Water footprint scenarios for 2050: a global analysis.

PubMed

Ercin, A Ertug; Hoekstra, Arjen Y

2014-03-01

This study develops water footprint scenarios for 2050 based on a number of drivers of change: population growth, economic growth, production/trade pattern, consumption pattern (dietary change, bioenergy use) and technological development. The objective the study is to understand the changes in the water footprint (WF) of production and consumption for possible futures by region and to elaborate the main drivers of this change. In addition, we assess virtual water flows between the regions of the world to show dependencies of regions on water resources in other regions under different possible futures. We constructed four scenarios, along two axes, representing two key dimensions of uncertainty: globalization versus regional selfsufficiency, and economy-driven development versus development driven by social and environmental objectives. The study shows how different drivers will change the level of water consumption and pollution globally in 2050. The presented scenarios can form a basis for a further assessment of how humanity can mitigate future freshwater scarcity. We showed with this study that reducing humanity's water footprint to sustainable levels is possible even with increasing populations, provided that consumption patterns change. This study can help to guide corrective policies at both national and international levels, and to set priorities for the years ahead in order to achieve sustainable and equitable use of the world's fresh water resources. Copyright © 2013 Elsevier Ltd. All rights reserved.

Land-use impacts on water resources and protected areas: applications of state-and-transition simulation modeling of future scenarios

NASA Astrophysics Data System (ADS)

Wilson, T. S.; Sleeter, B. M.; Sherba, J.; Cameron, D.

2014-12-01

Human land use will increasingly contribute to habitat losses and water shortages in California, given future population projections and associated demand for agricultural land. Understanding how land-use change may impact future water use and where existing protected areas may be threatened by land-use conversion will be important if effective, sustainable management approaches are to be implemented. We used a state-and-transition simulation modeling (STSM) framework to simulate spatially-explicit (1 km2) historical (1992-2010) and future (2011-2060) land-use change for 52 California counties within the Mediterranean California ecoregion. Historical land use change estimates were derived from the Farmland Mapping and Monitoring Program (FMMP) dataset and attributed with county-level agricultural water-use data from the California Department of Water Resources (CDWR). Six future alternative land-use scenarios were developed and modeled using the historical land-use change estimates and land-use projections based on the Intergovernmental Panel on Climate Change's (IPCC) Special Report on Emission Scenarios (SRES) A2 and B1 scenarios. Resulting spatial land-use scenario outputs were combined based on scenario agreement and a land conversion threat index developed to evaluate vulnerability of existing protected areas. Modeled scenario output of county-level agricultural water use data were also summarized, enabling examination of alternative water use futures. We present results of two separate applications of STSM of land-use change, demonstrating the utility of STSM in analyzing land-use related impacts on water resources as well as potential threats to existing protected land. Exploring a range of alternative, yet plausible, land-use change impacts will help to better inform resource management and mitigation strategies.

Future land-use related water demand in California

USGS Publications Warehouse

Wilson, Tamara; Sleeter, Benjamin M.; Cameron, D. Richard

2016-01-01

Water shortages in California are a growing concern amidst ongoing drought, earlier spring snowmelt, projected future climate warming, and currently mandated water use restrictions. Increases in population and land use in coming decades will place additional pressure on already limited available water supplies. We used a state-and-transition simulation model to project future changes in developed (municipal and industrial) and agricultural land use to estimate associated water use demand from 2012 to 2062. Under current efficiency rates, total water use was projected to increase 1.8 billion cubic meters(+4.1%) driven primarily by urbanization and shifts to more water intensive crops. Only if currently mandated 25% reductions in municipal water use are continuously implemented would water demand in 2062 balance to water use levels in 2012. This is the first modeling effort of its kind to examine regional land-use related water demand incorporating historical trends of both developed and agricultural land uses.

Simulating future water temperatures in the North Santiam River, Oregon

USGS Publications Warehouse

Buccola, Norman; Risley, John C.; Rounds, Stewart A.

2016-01-01

A previously calibrated two-dimensional hydrodynamic and water-quality model (CE-QUAL-W2) of Detroit Lake in western Oregon was used in conjunction with inflows derived from Precipitation-Runoff Modeling System (PRMS) hydrologic models to examine in-lake and downstream water temperature effects under future climate conditions. Current and hypothetical operations and structures at Detroit Dam were imposed on boundary conditions derived from downscaled General Circulation Models in base (1990–1999) and future (2059–2068) periods. Compared with the base period, future air temperatures were about 2 °C warmer year-round. Higher air temperature and lower precipitation under the future period resulted in a 23% reduction in mean annual PRMS-simulated discharge and a 1 °C increase in mean annual estimated stream temperatures flowing into the lake compared to the base period. Simulations incorporating current operational rules and minimum release rates at Detroit Dam to support downstream habitat, irrigation, and water supply during key times of year resulted in lower future lake levels. That scenario results in a lake level that is above the dam’s spillway crest only about half as many days in the future compared to historical frequencies. Managing temperature downstream of Detroit Dam depends on the ability to blend warmer water from the lake’s surface with cooler water from deep in the lake, and the spillway is an important release point near the lake’s surface. Annual average in-lake and release temperatures from Detroit Lake warmed 1.1 °C and 1.5 °C from base to future periods under present-day dam operational rules and fill schedules. Simulated dam operations such as beginning refill of the lake 30 days earlier or reducing minimum release rates (to keep more water in the lake to retain the use of the spillway) mitigated future warming to 0.4 and 0.9 °C below existing operational scenarios during the critical autumn spawning period for endangered salmonids. A hypothetical floating surface withdrawal at Detroit Dam improved temperature control in summer and autumn (0.6 °C warmer in summer, 0.6 °C cooler in autumn compared to existing structures) without altering release rates or lake level management rules.

Simulation of Ground-Water Flow in the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

USGS Publications Warehouse

Densmore, Jill N.

2003-01-01

Ground-water pumping in the Irwin Basin at Fort Irwin National Training Center, California resulted in water-level declines of about 30 feet from 1941 to 1996. Since 1992, artificial recharge from wastewater-effluent infiltration and irrigation-return flow has stabilized water levels, but there is concern that future water demands associated with expansion of the base may cause a resumption of water-level declines. To address these concerns, a ground-water flow model of the Irwin Basin was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Historical data show that ground-water-level declines in the Irwin Basin between 1941 and 1996, caused the formation of a pumping depression near the pumped wells, and that recharge from the wastewater-treatment facility and disposal area caused the formation of a recharge mound. There have been two periods of water-level recovery in the Irwin Basin since the development of ground water in this basin; these periods coincide with a period of decreased pumpage from the basin and a period of increased recharge of water imported from the Bicycle Basin beginning in 1967 and from the Langford Basin beginning in 1992. Since 1992, artificial recharge has exceeded pumpage in the Irwin Basin and has stabilized water-level declines. A two-layer ground-water flow model was developed to help better understand the aquifer system, assess the long-term availability and quality of ground water, and evaluate ground-water conditions owing to current pumping and to plan for future water needs at the base. Boundary conditions, hydraulic conductivity, altitude of the bottom of the layers, vertical conductance, storage coefficient, recharge, and discharge were determined using existing geohydrologic data. Rates and distribution of recharge and discharge were determined from existing data and estimated when unavailable. Results of predictive simulations indicate that in 50 years, if artificial recharge continues to exceed pumpage in Irwin Basin, water levels could rise as much as 65 feet beneath the pumping depression, and as much as 10 feet in the wastewater-treatment facility and disposal area. Particle-tracking simulations were used to determine the pathlines and the traveltimes of water high in dissolved solids into the main pumping area. The pathlines of particles from two areas with high dissolved-solids concentrations show that in 50 years water from these areas almost reaches the nearest pumped well.

Mediterranean California’s water use future under multiple scenarios of developed and agricultural land use change

USGS Publications Warehouse

Wilson, Tamara; Sleeter, Benjamin M.; Cameron, D. Richard

2017-01-01

With growing demand and highly variable inter-annual water supplies, California’s water use future is fraught with uncertainty. Climate change projections, anticipated population growth, and continued agricultural intensification, will likely stress existing water supplies in coming decades. Using a state-and-transition simulation modeling approach, we examine a broad suite of spatially explicit future land use scenarios and their associated county-level water use demand out to 2062. We examined a range of potential water demand futures sampled from a 20-year record of historical (1992–2012) data to develop a suite of potential future land change scenarios, including low/high change scenarios for urbanization and agriculture as well as “lowest of the low” and “highest of the high” anthropogenic use. Future water demand decreased 8.3 billion cubic meters (Bm3) in the lowest of the low scenario and decreased 0.8 Bm3 in the low agriculture scenario. The greatest increased water demand was projected for the highest of the high land use scenario (+9.4 Bm3), high agricultural expansion (+4.6 Bm3), and high urbanization (+2.1 Bm3) scenarios. Overall, these scenarios show agricultural land use decisions will likely drive future demand more than increasing municipal and industrial uses, yet improved efficiencies across all sectors could lead to potential water use savings. Results provide water managers with information on diverging land use and water use futures, based on historical, observed land change trends and water use histories.

Mediterranean California’s water use future under multiple scenarios of developed and agricultural land use change

PubMed Central

Sleeter, Benjamin M.; Cameron, D. Richard

2017-01-01

With growing demand and highly variable inter-annual water supplies, California’s water use future is fraught with uncertainty. Climate change projections, anticipated population growth, and continued agricultural intensification, will likely stress existing water supplies in coming decades. Using a state-and-transition simulation modeling approach, we examine a broad suite of spatially explicit future land use scenarios and their associated county-level water use demand out to 2062. We examined a range of potential water demand futures sampled from a 20-year record of historical (1992–2012) data to develop a suite of potential future land change scenarios, including low/high change scenarios for urbanization and agriculture as well as “lowest of the low” and “highest of the high” anthropogenic use. Future water demand decreased 8.3 billion cubic meters (Bm3) in the lowest of the low scenario and decreased 0.8 Bm3 in the low agriculture scenario. The greatest increased water demand was projected for the highest of the high land use scenario (+9.4 Bm3), high agricultural expansion (+4.6 Bm3), and high urbanization (+2.1 Bm3) scenarios. Overall, these scenarios show agricultural land use decisions will likely drive future demand more than increasing municipal and industrial uses, yet improved efficiencies across all sectors could lead to potential water use savings. Results provide water managers with information on diverging land use and water use futures, based on historical, observed land change trends and water use histories. PMID:29088254

Effects of Irrigation, Drought, and Ground-Water Withdrawals on Ground-Water Levels in the Southern Lihue Basin, Kauai, Hawaii

USGS Publications Warehouse

Izuka, Scot K.

2006-01-01

A numerical ground-water-flow model was used to investigate the effects of irrigation on ground-water levels in the southern Lihue Basin, Kauai, Hawaii, and the relation between declining ground-water levels observed in the basin in the 1990s and early 2000s and concurrent drought, irrigation reduction, and changes in ground-water withdrawal. Results of steady-state model simulations indicate that changing from pre-development to 1981 irrigation and ground-water-withdrawal conditions could, given enough time for steady state to be achieved, raise ground-water levels in some areas of the southern Lihue Basin by as much as 200 feet, and that changing from 1981 to 1998 irrigation and ground-water-withdrawal conditions could lower ground-water levels in some areas by as much as 100 feet. Transient simulations combining drought, irrigation reduction, and changes in ground-water withdrawal show trends that correspond with those observed in measured water levels. Results of this study indicate that irrigation reduction was the primary cause of the observed decline in ground-water-levels. In contrast, ground-water withdrawal had a long-duration but small-magnitude effect, and drought had a widespread, high-magnitude but short-duration effect. Inasmuch as irrigation in the future is unlikely to return to the same levels as during the period of peak sugarcane agriculture, the decline in ground-water levels resulting from the reduction and ultimate end of sugarcane irrigation can be considered permanent. Assuming that irrigation does not return to the southern Lihue Basin and that, on average, normal rainfall persists and ground-water withdrawal remains at 1998 rates, model projections indicate that average ground-water levels in the Kilohana-Puhi area will continue to recover from the drought of 1998-2002 and eventually rise to within about 4 feet of the pre-drought conditions. Long-term climate trends, increases in ground-water withdrawal, or other factors not simulated in the model could also affect ground-water levels in the southern Lihue Basin in the future.

Estuarine Response to River Flow and Sea-Level Rise under Future Climate Change and Human Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhaoqing; Wang, Taiping; Voisin, Nathalie

Understanding the response of river flow and estuarine hydrodynamics to climate change, land-use/land-cover change (LULC), and sea-level rise is essential to managing water resources and stress on living organisms under these changing conditions. This paper presents a modeling study using a watershed hydrology model and an estuarine hydrodynamic model, in a one-way coupling, to investigate the estuarine hydrodynamic response to sea-level rise and change in river flow due to the effect of future climate and LULC changes in the Snohomish River estuary, Washington, USA. A set of hydrodynamic variables, including salinity intrusion points, average water depth, and salinity of themore » inundated area, were used to quantify the estuarine response to river flow and sea-level rise. Model results suggest that salinity intrusion points in the Snohomish River estuary and the average salinity of the inundated areas are a nonlinear function of river flow, although the average water depth in the inundated area is approximately linear with river flow. Future climate changes will shift salinity intrusion points further upstream under low flow conditions and further downstream under high flow conditions. In contrast, under the future LULC change scenario, the salinity intrusion point will shift downstream under both low and high flow conditions, compared to present conditions. The model results also suggest that the average water depth in the inundated areas increases linearly with sea-level rise but at a slower rate, and the average salinity in the inundated areas increases linearly with sea-level rise; however, the response of salinity intrusion points in the river to sea-level rise is strongly nonlinear.« less

Past and future water conflicts in the Upper Klamath Basin: An economic appraisal

NASA Astrophysics Data System (ADS)

Boehlert, Brent B.; Jaeger, William K.

2010-10-01

The water conflict in the Upper Klamath Basin typifies the growing competition between agricultural and environmental water uses. In 2001, drought conditions triggered Endangered Species Act-related requirements that curtailed irrigation diversions to the Klamath Reclamation Project, costing irrigators tens of millions of dollars. Although this event has significantly elevated the perceived risk of future economic catastrophe in the basin (and therefore the level of conflict among water users), several key changes related to water availability have occurred since 2001. These changes include reduced ESA requirements and increased groundwater pumping capacity, which have lowered the actual risk and severity of future water shortages. In this paper, we use a mathematical programming model to evaluate how these changes alter the likelihood and economic consequences of future shortages. We also consider the effect of more flexible transfers among irrigators via water markets. Our analysis indicates that future drought conditions like those seen in 2001 would have more modest economic impacts than in 2001 and that when combined with contingent groundwater supplementation and water transfer mechanisms such as water markets, both the likelihood and magnitude of economic losses among irrigators would be greatly reduced.

Simulated water-level and water-quality changes in the bolson-fill aquifer, Post Headquarters area, White Sands Missile Range, New Mexico

USGS Publications Warehouse

Risser, D.W.

1988-01-01

The quantity of freshwater available in the Post Headquarters well field, White Sand Missile Range, New Mexico, is limited and its quality is threatened by saltwater enroachment. A three-dimensional, finite-difference, groundwater flow model and a cross-sectional, density-dependent solute-transport model were constructed to simulate possible future water level declines and water quality changes in the Post Headquarters well field. A six-layer flow model was constructed using hydraulic-conductivity values in the upper 600 ft of saturated aquifer ranging from 0.1 to 10 ft/day, specific yield of 0.15, and average recharge of about 1,590 acre-ft/yr. Water levels simulated by the model closely matched measured water levels for 1948-82. Possible future water level changes for 1983-2017 were simulated using rates of groundwater withdrawal of 1,033 and 2 ,066 acre-ft/year and wastewater return flow of 0 or 30% of the groundwater withdrawal rate. The cross-sectional solute-transport model indicated that the freshwater zone is about 1,500 to 2,000 ft thick beneath the well field. Transient simulations show that solutes probably will move laterally toward the well field rather than from beneath the well field. (USGS)

Applying downscaled global climate model data to a hydrodynamic surface-water and groundwater model

USGS Publications Warehouse

Swain, Eric; Stefanova, Lydia; Smith, Thomas

2014-01-01

Precipitation data from Global Climate Models have been downscaled to smaller regions. Adapting this downscaled precipitation data to a coupled hydrodynamic surface-water/groundwater model of southern Florida allows an examination of future conditions and their effect on groundwater levels, inundation patterns, surface-water stage and flows, and salinity. The downscaled rainfall data include the 1996-2001 time series from the European Center for Medium-Range Weather Forecasting ERA-40 simulation and both the 1996-1999 and 2038-2057 time series from two global climate models: the Community Climate System Model (CCSM) and the Geophysical Fluid Dynamic Laboratory (GFDL). Synthesized surface-water inflow datasets were developed for the 2038-2057 simulations. The resulting hydrologic simulations, with and without a 30-cm sea-level rise, were compared with each other and field data to analyze a range of projected conditions. Simulations predicted generally higher future stage and groundwater levels and surface-water flows, with sea-level rise inducing higher coastal salinities. A coincident rise in sea level, precipitation and surface-water flows resulted in a narrower inland saline/fresh transition zone. The inland areas were affected more by the rainfall difference than the sea-level rise, and the rainfall differences make little difference in coastal inundation, but a larger difference in coastal salinities.

Risk-based water resources planning: Incorporating probabilistic nonstationary climate uncertainties

NASA Astrophysics Data System (ADS)

Borgomeo, Edoardo; Hall, Jim W.; Fung, Fai; Watts, Glenn; Colquhoun, Keith; Lambert, Chris

2014-08-01

We present a risk-based approach for incorporating nonstationary probabilistic climate projections into long-term water resources planning. The proposed methodology uses nonstationary synthetic time series of future climates obtained via a stochastic weather generator based on the UK Climate Projections (UKCP09) to construct a probability distribution of the frequency of water shortages in the future. The UKCP09 projections extend well beyond the range of current hydrological variability, providing the basis for testing the robustness of water resources management plans to future climate-related uncertainties. The nonstationary nature of the projections combined with the stochastic simulation approach allows for extensive sampling of climatic variability conditioned on climate model outputs. The probability of exceeding planned frequencies of water shortages of varying severity (defined as Levels of Service for the water supply utility company) is used as a risk metric for water resources planning. Different sources of uncertainty, including demand-side uncertainties, are considered simultaneously and their impact on the risk metric is evaluated. Supply-side and demand-side management strategies can be compared based on how cost-effective they are at reducing risks to acceptable levels. A case study based on a water supply system in London (UK) is presented to illustrate the methodology. Results indicate an increase in the probability of exceeding the planned Levels of Service across the planning horizon. Under a 1% per annum population growth scenario, the probability of exceeding the planned Levels of Service is as high as 0.5 by 2040. The case study also illustrates how a combination of supply and demand management options may be required to reduce the risk of water shortages.

Monitoring Lake and Reservoir Level: Satellite Observations, Modeling and Prediction

NASA Astrophysics Data System (ADS)

Ricko, M.; Birkett, C. M.; Adler, R. F.; Carton, J.

2013-12-01

Satellite measurements of lake and reservoir water levels complement in situ observations by providing stage information for un-gauged basins and by filling data gaps in gauge records. However, different satellite radar altimeter-derived continental water level products may differ significantly owing to choice of satellites and data processing methods. To explore the impacts of these differences, a direct comparison between three different altimeter-based surface water level estimates (USDA/NASA GRLM, LEGOS and ESA-DMU) will be presented and products validated with lake level gauge time series for lakes and reservoirs of a variety of sizes and conditions. The availability of satellite-based rainfall (i.e., TRMM and GPCP) and satellite-based lake/reservoir levels offers exciting opportunities to estimate and monitor the hydrologic properties of the lake systems. Here, a simple water balance model is utilized to relate net freshwater flux on a catchment basin to lake/reservoir level. Focused on tropical lakes and reservoirs it allows a comparison of the flux to altimetric lake level estimates. The combined use of model, satellite-based rainfall, evaporation information and reanalysis products, can be used to output water-level hindcasts and seasonal future forecasts. Such a tool is fundamental for understanding present-day and future variations in lake/reservoir levels and enabling a better understand of climatic variations on inter-annual to inter-decadal time-scales. New model-derived water level estimates of lakes and reservoirs, on regional to global scales, would assist communities with interests in climate studies focusing on extreme events, such as floods and droughts, and be important for water resources management.

Climate Sensitivity Runs and Regional Hydrologic Modeling for Predicting the Response of the Greater Florida Everglades Ecosystem to Climate Change

NASA Astrophysics Data System (ADS)

Obeysekera, Jayantha; Barnes, Jenifer; Nungesser, Martha

2015-04-01

It is important to understand the vulnerability of the water management system in south Florida and to determine the resilience and robustness of greater Everglades restoration plans under future climate change. The current climate models, at both global and regional scales, are not ready to deliver specific climatic datasets for water resources investigations involving future plans and therefore a scenario based approach was adopted for this first study in restoration planning. We focused on the general implications of potential changes in future temperature and associated changes in evapotranspiration, precipitation, and sea levels at the regional boundary. From these, we developed a set of six climate and sea level scenarios, used them to simulate the hydrologic response of the greater Everglades region including agricultural, urban, and natural areas, and compared the results to those from a base run of current conditions. The scenarios included a 1.5 °C increase in temperature, ±10 % change in precipitation, and a 0.46 m (1.5 feet) increase in sea level for the 50-year planning horizon. The results suggested that, depending on the rainfall and temperature scenario, there would be significant changes in water budgets, ecosystem performance, and in water supply demands met. The increased sea level scenarios also show that the ground water levels would increase significantly with associated implications for flood protection in the urbanized areas of southeastern Florida.

18 CFR 806.23 - Standards for water withdrawals.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of groundwater or stream flow levels; rendering competing supplies unreliable; affecting other water..., at its own expense, an alternate water supply or other mitigating measures. (iii) Require the project... deficiencies, identify alternative water supply options, and support existing and proposed future withdrawals. ...

Extreme Water Levels in Bangladesh: Past Trends, Future Projections and their Impact on Mortality

NASA Astrophysics Data System (ADS)

Thiele-Eich, I.; Burkart, K.; Hopson, T. M.; Simmer, C.

2014-12-01

Climate change is expected to have an impact on meteorological and therefore hydrological extremes, thereby possibly altering the vulnerability of exposed populations. Our study focuses on Bangladesh, which is particularly vulnerable to changes in extremes due to both the large population at risk, as well as geographical characteristics such as the low-rising slope of the country through which the outflow of the combined catchments of the Ganges, Brahmaputra and Meghna rivers (GBM, ~1.75 million km2) is channeled.Time series of daily discharge and water level data for the past 100 years were analyzed with respect to trends in frequency, magnitude and duration, focusing on rare but particularly high-risk events using extreme-value theory. Mortality data is available for a five-year period (2003-2007), with a distributed lag non-linear model used to examine possible connections between extreme water levels and mortality. Then, using output from the Community Climate System Model CCSM4, projections were made regarding future flooding due to changes in precipitation intensity and frequency, while also accounting for the backwater effect of sea-level rise. For this, the upper catchment precipitation as well as monthly mean thermosteric sea-level rise at the river mouth outflow were taken from the four CCSM4 1° 20th Century ensemble members as well as from six CCSM4 1° ensemble members for the RCP scenarios RCP 2.6, 4.5, 6.0 and 8.5.Results show that while e.g. the mean water level did not significantly rise during the past 100 years, a change in extreme water levels can be detected. In addition, annual minimum water levels have decreased, which is of particular importance as there is a significant connection to an increase in mortality for low water levels. While mortality does not seem to increase significantly due to extreme floods, our results indicate that return levels projected for the future shift progressively, with the effect being strongest for RCP 8.5. Further measures to strengthen the resilience of the exposed population are therefore required to ensure that climate change effects do not overwhelm the population's coping capacities.

Simulation of a proposed emergency outlet from Devils Lake, North Dakota

USGS Publications Warehouse

Vecchia, Aldo V.

2002-01-01

From 1993 to 2001, Devils Lake rose more than 25 feet, flooding farmland, roads, and structures around the lake and causing more than $400 million in damages in the Devils Lake Basin. In July 2001, the level of Devils Lake was at 1,448.0 feet above sea level1, which was the highest lake level in more than 160 years. The lake could continue to rise to several feet above its natural spill elevation to the Sheyenne River (1,459 feet above sea level) in future years, causing extensive additional flooding in the basin and, in the event of an uncontrolled natural spill, downstream in the Red River of the North Basin as well. The outlet simulation model described in this report was developed to determine the potential effects of various outlet alternatives on the future lake levels and water quality of Devils Lake.Lake levels of Devils Lake are controlled largely by precipitation on the lake surface, evaporation from the lake surface, and surface inflow. For this study, a monthly water-balance model was developed to compute the change in total volume of Devils Lake, and a regression model was used to estimate monthly water-balance data on the basis of limited recorded data. Estimated coefficients for the regression model indicated fitted precipitation on the lake surface was greater than measured precipitation in most months, fitted evaporation from the lake surface was less than estimated evaporation in most months, and ungaged inflow was about 2 percent of gaged inflow in most months. Dissolved sulfate was considered to be the key water-quality constituent for evaluating the effects of a proposed outlet on downstream water quality. Because large differences in sulfate concentrations existed among the various bays of Devils Lake, monthly water-balance data were used to develop detailed water and sulfate mass-balance models to compute changes in sulfate load for each of six major storage compartments in response to precipitation, evaporation, inflow, and outflow from each compartment. The storage compartments--five for Devils Lake and one for Stump Lake--were connected by bridge openings, culverts, or natural channels that restricted mixing between compartments. A numerical algorithm was developed to calculate inflow and outflow from each compartment. Sulfate loads for the storage compartments first were calculated using the assumptions that no interaction occurred between the bottom sediments and the water column and no wind- or buoyancy-induced mixing occurred between compartments. However, because the fitted sulfate loads did not agree with the estimated sulfate loads, which were obtained from recorded sulfate concentrations, components were added to the sulfate mass-balance model to account for the flux of sulfate between bottom sediments and the lake and for mixing between storage compartments. Mixing between compartments can occur during periods of open water because of wind and during periods of ice cover because of water-density differences between compartments. Sulfate loads calculated using the sulfate mass-balance model with sediment interaction and mixing between compartments closely matched sulfate loads computed from historical concentrations. The water and sulfate mass-balance models were used to calculate potential future lake levels and sulfate concentrations for Devils Lake and Stump Lake given potential future values of monthly precipitation, evaporation, and inflow. Potential future inputs were generated using a scenario approach and a stochastic approach. In the scenario approach, historical values of precipitation, evaporation, and inflow were repeated in the future for a particular sequence of historical years. In the stochastic approach, a statistical time-series model was developed to randomly generate potential future inputs. The scenario approach was used to evaluate the effectiveness of various outlet alternatives, and the stochastic approach was used to evaluate the hydrologic and water-quality effects of the potential outlet alternatives that were selected on the basis of the scenario analysis. Given potential future lake levels and sulfate concentrations generated using either the scenario or stochastic approach and potential future ambient flows and sulfate concentrations for the Sheyenne River receiving waters, daily outlet discharges could be calculated for virtually any outlet alternative. For the scenario approach, future ambient flows and sulfate concentrations for the Sheyenne River were generated using the same sequence of years used for generating water-balance data for Devils Lake. For the stochastic approach, a procedure was developed for generating daily Sheyenne River flows and sulfate concentrations that were "in-phase" with the generated water-balance data for Devils Lake. Simulation results for the scenario approach indicated that neither of the West Bay outlet alternatives provided effective flood-damage reduction without exceeding downstream water-quality constraints. However, both Pelican Lake outlet alternatives provided significant flood-damage reduction with only minor downstream water-quality changes. The most effective alternative for controlling rising lake levels was a Pelican Lake outlet with a 480-cubic-foot-per-second pump capacity and a 250-milligram-per-liter downstream sulfate constraint. However, this plan is costly because of the high pump capacity and the requirement of a control structure on Highway 19 to control the level of Pelican Lake. A less costly, though less effective for flood-damage reduction, plan is a Pelican Lake outlet with a 300-cubic-foot-per-second pump capacity and a 250-milligram-per-liter downstream sulfate constraint. The plan is less costly because the pump capacity is smaller and because the control structure on Highway 19 is not required. The less costly Pelican Lake alternative with a 450-milligramper- liter downstream sulfate constraint rather than a 250-milligram-per-liter downstream sulfate constraint was identified by the U.S. Army Corps of Engineers as the preferred alternative for detailed design and engineering analysis. Simulation results for the stochastic approach indicated that the geologic history of lake-level fluctuations of Devils Lake for the past 2,500 years was consistent with a climatic history that consisted of two climate states--a wet state, similar to conditions during 1980-99, and a normal state, similar to conditions during 1950-78. The transition times between the wet and normal climatic periods occurred randomly. The average duration of the wet climatic periods was 20 years, and the average duration of the normal climatic periods was 120 years. The stochastic approach was used to generate 10,000 independent sequences of lake levels and sulfate concentrations for Devils Lake for water years 2001-50. Each trace began with the same starting conditions, and the duration of the current wet cycle was generated randomly for each trace. Each trace was generated for the baseline (natural) condition and for the Pelican Lake outlet with a 300-cubic-foot-per-second pump capacity and a 450-milligram-per-liter downstream sulfate constraint. The outlet significantly lowered the probabilities of future lake-level increases within the next 50 years and did not substantially increase the probabilities of reaching low lake levels or poor water-quality conditions during the same period.

Review of Knowledge on the Occurrence, Chemical Composition, and Potential Use for Desalination of Saline Ground Water in Arizona, New Mexico, and Texas with a Discussion of Potential Future Study Needs

USGS Publications Warehouse

Huff, G.F.

2004-01-01

Increasing demand on the limited supplies of freshwater in the desert Southwest, as well as other parts of the United States, has increased the level of interest in saline-water resources. Saline ground water has long been recognized as a potentially important contributor to water supply in the Southwest, as demonstrated by the number of hydrologic, geologic, and engineering studies on the distribution of saline water and the feasibility of desalination. Potential future study needs include investigating and documenting the three-dimensional distribution of salinity and chemical composition of saline-water resources and the hydraulic properties of aquifers containing these saline-water resources, assessing the chemical suitability of saline water for use with existing and anticipated desalination technologies, simulating the effect of withdrawal of saline ground water on water levels and water composition in saline and adjoining or overlying freshwater aquifers, and determining the suitability of target geologic formations for injection of desalination-generated waste.

Aquifer-System Compaction and Land Subsidence: Measurements, Analyses, and Simulations-the Holly Site, Edwards Air Force Base, Antelope Valley, California

USGS Publications Warehouse

Sneed, Michelle; Galloway, Devin L.

2000-01-01

Land subsidence resulting from ground-water-level declines has long been recognized as a problem in Antelope Valley, California. At Edwards Air Force Base (EAFB), ground-water extractions have caused more than 150 feet of water-level decline, resulting in nearly 4 feet of subsidence. Differential land subsidence has caused sinklike depressions and earth fissures and has accelerated erosion of the playa lakebed surface of Rogers Lake at EAFB, adversely affecting the runways on the lakebed which are used for landing aircraft such as the space shuttles. Since 1990, about 0.4 foot of aquifer-system compaction has been measured at a deep (840 feet) borehole extensometer (Holly site) at EAFB. More than 7 years of paired ground-water-level and aquifer-system compaction measurements made at the Holly site were analyzed for this study. Annually, seasonal water-level fluctuations correspond to steplike variations in aquifer-system compaction; summer water-level drawdowns are associated with larger rates of compaction, and winter water-level recoveries are associated with smaller rates of compaction. The absence of aquifer-system expansion during recovery is consistent with the delayed drainage and resultant delayed, or residual, compaction of thick aquitards. A numerical one-dimensional MODFLOW model of aquitard drainage was used to refine estimates of aquifer-system hydraulic parameters that control compaction and to predict potential future compaction at the Holly site. The analyses and simulations of aquifer-system compaction are based on established theories of aquitard drainage. Historical ground-water-level and land-subsidence data collected near the Holly site were used to constrain simulations of aquifer-system compaction and land subsidence at the site for the period 1908?90, and ground-water-level and aquifer- system compaction measurements collected at the Holly site were used to constrain the model for the period 1990?97. Model results indicate that two thick aqui- tards, which total 129 feet or about half the aggregate thickness of all the aquitards penetrated by the Holly boreholes, account for most (greater than 99 percent) of the compaction measured at the Holly site during the period 1990?97. The results of three scenarios of future water-level changes indicate that these two thick aquitards account for most of the future compaction. The results also indicate that if water levels decline to about 30 feet below the 1997 water levels an additional 1.7 feet of compaction may occur during the next 30 years. If water levels remain at 1997 levels, the model predicts that only 0.8 foot of compaction may occur during the same period, and even if water levels recover to about 30 feet above 1997 water levels, another 0.5 foot of compaction may occur in the next 30 years. In addition, only a portion of the compaction that ultimately will occur likely will occur within the next 30 years; therefore, the residual compaction and associated land subsidence attributed to slowly equilibrating aquitards is important to consider in the long-term management of land and water resources at EAFB.

Blue water scarcity and the economic impacts of future agricultural trade and demand

NASA Astrophysics Data System (ADS)

Schmitz, Christoph; Lotze-Campen, Hermann; Gerten, Dieter; Dietrich, Jan Philipp; Bodirsky, Benjamin; Biewald, Anne; Popp, Alexander

2013-06-01

An increasing demand for agricultural goods affects the pressure on global water resources over the coming decades. In order to quantify these effects, we have developed a new agroeconomic water scarcity indicator, considering explicitly economic processes in the agricultural system. The indicator is based on the water shadow price generated by an economic land use model linked to a global vegetation-hydrology model. Irrigation efficiency is implemented as a dynamic input depending on the level of economic development. We are able to simulate the heterogeneous distribution of water supply and agricultural water demand for irrigation through the spatially explicit representation of agricultural production. This allows in identifying regional hot spots of blue water scarcity and explicit shadow prices for water. We generate scenarios based on moderate policies regarding future trade liberalization and the control of livestock-based consumption, dependent on different population and gross domestic product (GDP) projections. Results indicate increased water scarcity in the future, especially in South Asia, the Middle East, and north Africa. In general, water shadow prices decrease with increasing liberalization, foremost in South Asia, Southeast Asia, and the Middle East. Policies to reduce livestock consumption in developed countries not only lower the domestic pressure on water but also alleviate water scarcity to a large extent in developing countries. It is shown that one of the two policy options would be insufficient for most regions to retain water scarcity in 2045 on levels comparable to 2005.

Sustainable-yield estimation for the Sparta Aquifer in Union County, Arkansas

USGS Publications Warehouse

Hays, Phillip D.

2000-01-01

Options for utilizing alternative sources of water to alleviate overdraft from the Sparta aquifer and ensure that the aquifer can continue to provide abundant water of excellent quality for the future are being evaluated by water managers in Union County. Sustainable yield is a critical element in identifying and designing viable water supply alternatives. With sustainable yield defined and a knowledge of total water demand in an area, any unmet demand can be calculated. The ground-water flow model of the Sparta aquifer was used to estimate sustainable yield using an iterative approach. The Sparta aquifer is a confined aquifer of regional importance that comprises a sequence of unconsolidated sand units that are contained within the Sparta Sand. Currently, the rate of withdrawal in some areas greatly exceeds the rate of recharge to the aquifer and considerable water-level declines have occurred. Ground-water flow model results indicate that the aquifer cannot continue to meet growing water-use demands indefinitely and that water levels will drop below the top of the primary producing sand unit in Union County (locally termed the El Dorado sand) by 2008 if current water-use trends continue. Declines of that magnitude will initiate dewatering of the El Dorado sand. The sustainable yield of the aquifer was calculated by targeting a specified minimum acceptable water level within Union County and varying Union County pumpage within the model to achieve the target water level. Selection of the minimum target water level for sustainable-yield estimation was an important criterion for the modeling effort. In keeping with the State Critical Ground-Water Area designation criteria and the desire of water managers in Union County to improve aquifer conditions and bring the area out of the Critical Ground-Water Area designation, the approximate altitude of the top of the Sparta Sand in central Union County was used as the minimum water level target for estimation of sustainable yield in the county. A specific category of sustainable yield? stabilization yield, reflecting the amount of water that the aquifer can provide while maintaining current water levels? also was determined and provides information for short-term management. The top of the primary producing sand unit (the El Dorado sand) was used as the minimum water-level target for estimating stabilization yield in the county because current minimum water levels in central Union County are near the top of the El Dorado sand. Model results show that withdrawals from the Sparta aquifer in Union County must be reduced to 28 percent of 1997 values to achieve sustainable yield and maintain water levels at the top of the Sparta Sand if future pumpage outside of Union County is assumed to increase at the rate observed from 1985-1997. Results of the simulation define a very large current unmet demand and represent a substantial reduction in the county?s current dependence upon the aquifer. If future pumpage outside of Union County is assumed to increase at double the rate observed from 1985-1997, withdrawals from the Sparta aquifer in Union County must be reduced to 25 percent of 1997 values to achieve sustainable yield. Withdrawals from the Sparta aquifer in Union County must be reduced to about 88 to 91 percent (depending on pumpage growth outside of the county) of 1997 values to stabilize water levels at the top of the El Dorado sand. This result shows that 1997 rate of withdrawal in the county is considerably greater than the rate needed to halt the rapid decline in water levels.

Historical and hypothetical future sedimentation and water storage in Kajakai Reservoir, central Afghanistan

USGS Publications Warehouse

Vining, Kevin C.; Vecchia, Aldo V.

2008-01-01

Sedimentation has reduced water storage in Kajakai Reservoir. If current sedimentation rates continue, hypothetical future reservoir water volumes at the spillway elevation of 1,033.5 meters could be reduced about 22 percent from 2006 to 2057. Even if the spillway elevation is raised to 1,045 meters, a severe drought could result in large multiyear irrigation-supply deficits in which reservoir water levels remain below 1,022 meters for more than 4 years. Hypothetical climate change and sedimentation could result in greater water-supply deficits. The chance of having sufficient water supplies in Kajakai Reservoir during the worst month is about 47 percent.

Conjunctive management of surface and groundwater resources under projected future climate change scenarios

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mani, Amir; Tsai, Frank T. -C.; Kao, Shih-Chieh

Our study introduces a mixed integer linear fractional programming (MILFP) method to optimize conjunctive use of future surface water and groundwater resources under projected climate change scenarios. The conjunctive management model maximizes the ratio of groundwater usage to reservoir water usage. Future inflows to the reservoirs were estimated from the future runoffs projected through hydroclimate modeling considering the Variable Infiltration Capacity model, and 11 sets of downscaled Coupled Model Intercomparison Project phase 5 global climate model projections. Bayesian model averaging was adopted to quantify uncertainty in future runoff projections and reservoir inflow projections due to uncertain future climate projections. Optimizedmore » conjunctive management solutions were investigated for a water supply network in northern Louisiana which includes the Sparta aquifer. Runoff projections under climate change scenarios indicate that runoff will likely decrease in winter and increase in other seasons. Ultimately, results from the developed conjunctive management model with MILFP indicate that the future reservoir water, even at 2.5% low inflow cumulative probability level, could counterbalance groundwater pumping reduction to satisfy demands while improving the Sparta aquifer through conditional groundwater head constraint.« less

Conjunctive management of surface and groundwater resources under projected future climate change scenarios

DOE PAGES

Mani, Amir; Tsai, Frank T. -C.; Kao, Shih-Chieh; ...

2016-06-16

Our study introduces a mixed integer linear fractional programming (MILFP) method to optimize conjunctive use of future surface water and groundwater resources under projected climate change scenarios. The conjunctive management model maximizes the ratio of groundwater usage to reservoir water usage. Future inflows to the reservoirs were estimated from the future runoffs projected through hydroclimate modeling considering the Variable Infiltration Capacity model, and 11 sets of downscaled Coupled Model Intercomparison Project phase 5 global climate model projections. Bayesian model averaging was adopted to quantify uncertainty in future runoff projections and reservoir inflow projections due to uncertain future climate projections. Optimizedmore » conjunctive management solutions were investigated for a water supply network in northern Louisiana which includes the Sparta aquifer. Runoff projections under climate change scenarios indicate that runoff will likely decrease in winter and increase in other seasons. Ultimately, results from the developed conjunctive management model with MILFP indicate that the future reservoir water, even at 2.5% low inflow cumulative probability level, could counterbalance groundwater pumping reduction to satisfy demands while improving the Sparta aquifer through conditional groundwater head constraint.« less

Towards a global water scarcity risk assessment framework: using scenarios and risk distributions

NASA Astrophysics Data System (ADS)

Veldkamp, Ted; Wada, Yoshihide; Aerts, Jeroen; Ward, Philip

2016-04-01

Over the past decades, changing hydro-climatic and socioeconomic conditions have led to increased water scarcity problems. A large number of studies have shown that these water scarcity conditions will worsen in the near future. Despite numerous calls for risk-based assessments of water scarcity, a framework that includes UNISDR's definition of risk does not yet exist at the global scale. This study provides a first step towards such a risk-based assessment, applying a Gamma distribution to estimate water scarcity conditions at the global scale under historic and future conditions, using multiple climate change projections and socioeconomic scenarios. Our study highlights that water scarcity risk increases given all future scenarios, up to >56.2% of the global population in 2080. Looking at the drivers of risk, we find that population growth outweigh the impacts of climate change at global and regional scales. Using a risk-based method to assess water scarcity in terms of Expected Annual Exposed Population, we show the results to be less sensitive than traditional water scarcity assessments to the use of fixed threshold to represent different levels of water scarcity. This becomes especially important when moving from global to local scales, whereby deviations increase up to 50% of estimated risk levels. Covering hazard, exposure, and vulnerability, risk-based methods are well-suited to assess water scarcity adaptation. Completing the presented risk framework therefore offers water managers a promising perspective to increase water security in a well-informed and adaptive manner.

Potential impacts of global warming on water resources in southern California.

PubMed

Beuhler, M

2003-01-01

Global warming will have a significant impact on water resources within the 20 to 90-year planning period of many water projects. Arid and semi-arid regions such as Southern California are especially vulnerable to anticipated negative impacts of global warming on water resources. Long-range water facility planning must consider global climate change in the recommended mix of new facilities needed to meet future water requirements. The generally accepted impacts of global warming include temperature, rising sea levels, more frequent and severe floods and droughts, and a shift from snowfall to rain. Precipitation changes are more difficult to predict. For Southern California, these impacts will be especially severe on surface water supplies. Additionally, rising sea levels will exacerbate salt-water intrusion into freshwater and impact the quality of surface water supplies. Integrated water resources planning is emerging as a tool to develop water supplies and demand management strategies that are less vulnerable to the impacts of global warming. These tools include water conservation, conjunctive use of surface and groundwater and desalination of brackish water and possibly seawater. Additionally, planning for future water needs should include explicit consideration of the potential range of global warming impacts through techniques such as scenario planning.

Hydrologic influences on water-level changes in the Eastern Snake River Plain aquifer at and near the Idaho National Laboratory, Idaho, 1949-2014

USGS Publications Warehouse

Bartholomay, Roy C.; Twining, Brian V.

2015-01-01

Geophysical logs indicate that most of the wells evaluated will maintain their current production until the water level declines to the depth of the pump. A few of the wells may become less productive once the water level gets to within about 5 ft from the top of the pump. Wells most susceptible to future drought cycles are those in the northeastern and northwestern areas of the INL.

Catchments' hedging strategy on evapotranspiration for climatic variability

NASA Astrophysics Data System (ADS)

Ding, W.; Zhang, C.; Li, Y.; Tang, Y.; Wang, D.; Xu, B.

2017-12-01

Hydrologic responses to climate variability and change are important for human society. Here we test the hypothesis that natural catchments utilize hedging strategies for evapotranspiration and water storage carryover with uncertain future precipitation. The hedging strategy for evapotranspiration in catchments under different levels of water availability is analytically derived from the economic perspective. It is found that there exists hedging between evapotranspiration for current and future only with a portion of water availability. Observation data sets of 160 catchments in the United States covering the period from 1983 to 2003 demonstrate the existence of hedging in catchment hydrology and validate the proposed hedging strategies. We also find that more water is allocated to carryover storage for hedging against the future evapotranspiration risk in the catchments with larger aridity indexes or with larger uncertainty in future precipitation, i.e., long-term climate and precipitation variability control the degree of hedging.

Evaporation from a temperate closed-basin lake and its impact on present, past, and future water level

USDA-ARS?s Scientific Manuscript database

Lakes provide enormous economic, recreational, and aesthetic benefits to citizens. These ecosystem services may be adversely impacted by climate change. In the Twin Cities Metropolitan Area of Minnesota, USA, many lakes have been at historic low levels and water augmentation strategies have been pro...

Method for Assessing Impacts of Global Sea Level Rise on Navigation Gate Operations

NASA Astrophysics Data System (ADS)

Obrien, P. S.; White, K. D.; Friedman, D.

2015-12-01

Coastal navigation infrastructure may be highly vulnerable to changing climate, including increasing sea levels and altered frequency and intensity of coastal storms. Future gate operations impacted by global sea level rise will pose unique challenges, especially for structures 50 years and older. Our approach is to estimate future changes in gate operational frequency based on a bootstrapping method to forecast future water levels. A case study will be presented to determine future changes in frequency of operations over the next 100 years. A statistical model in the R programming language was developed to apply future sea level rise projections using the three sea level rise scenarios prescribed by USACE Engineer Regulation ER 1100-2-8162. Information derived from the case study will help forecast changes in operational costs caused by increased gate operations and inform timing of decisions on adaptation measures.

Analysis of the ecological water diversion project in Wenzhou City

NASA Astrophysics Data System (ADS)

Xu, Haibo; Fu, Lei; Lin, Tong

2018-02-01

As a developed city in China, Wenzhou City has been suffered from bad water quality for years. In order to improve the river network water quality, an ecological water diversion project was designed and executed by the regional government. In this study, an investigation and analysis of the regional ecological water diversion project is made for the purpose of examining the water quality improvements. A numerical model is also established, different water diversion flow rates and sewer interception levels are considered during the simulation. Simulation results reveal that higher flow rate and sewer interception level will greatly improve the river network water quality in Wenzhou City. The importance of the flow rate and interception level has been proved and future work will be focused on increasing the flow rate and upgrading the sewer interception level.

Energy and Water

ERIC Educational Resources Information Center

Harte, John; El-Gasseir, Mohamed

1978-01-01

The water consumption requirements for a variety of energy options are presented, and comparative judgments drawn. Attention is focused on problems resulting from synthetic, gaseous, and liquid fuel production. Scenarios describing possible future levels of coal and electricity use are analyzed. They point to the importance of water supply…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fant, Charles; Schlosser, C. Adam; Gao, Xiang

The sustainability of future water resources is of paramount importance and is affected by many factors, including population, wealth and climate. Inherent in current methods to estimate these factors in the future is the uncertainty of their prediction. In this study, we integrate a large ensemble of scenarios—internally consistent across economics, emissions, climate, and population—to develop a risk portfolio of water stress over a large portion of Asia that includes China, India, and Mainland Southeast Asia in a future with unconstrained emissions. We isolate the effects of socioeconomic growth from the effects of climate change in order to identify themore » primary drivers of stress on water resources. We find that water needs related to socioeconomic changes, which are currently small, are likely to increase considerably in the future, often overshadowing the effect of climate change on levels of water stress. As a result, there is a high risk of severe water stress in densely populated watersheds by 2050, compared to recent history. There is strong evidence to suggest that, in the absence of autonomous adaptation or societal response, a much larger portion of the region’s population will live in water-stressed regions in the near future. Lastly, tools and studies such as these can effectively investigate large-scale system sensitivities and can be useful in engaging and informing decision makers.« less

Coastal vulnerability across the Pacific dominated by El Niño-Southern Oscillation

USGS Publications Warehouse

Barnard, Patrick L.; Short, Andrew D.; Harley, Mitchell D.; Splinter, Kristen D.; Vitousek, Sean; Turner, Ian L.; Allan, Jonathan; Banno, Masayuki; Bryan, Karin R.; Doria, André; Hansen, Jeff E.; Kato, Shigeru; Kuriyama, Yoshiaki; Randall-Goodwin, Evan; Ruggiero, Peter; Walker, Ian J.; Heathfield, Derek K.

2015-01-01

To predict future coastal hazards, it is important to quantify any links between climate drivers and spatial patterns of coastal change. However, most studies of future coastal vulnerability do not account for the dynamic components of coastal water levels during storms, notably wave-driven processes, storm surges and seasonal water level anomalies, although these components can add metres to water levels during extreme events. Here we synthesize multi-decadal, co-located data assimilated between 1979 and 2012 that describe wave climate, local water levels and coastal change for 48 beaches throughout the Pacific Ocean basin. We find that observed coastal erosion across the Pacific varies most closely with El Niño/Southern Oscillation, with a smaller influence from the Southern Annular Mode and the Pacific North American pattern. In the northern and southern Pacific Ocean, regional wave and water level anomalies are significantly correlated to a suite of climate indices, particularly during boreal winter; conditions in the northeast Pacific Ocean are often opposite to those in the western and southern Pacific. We conclude that, if projections for an increasing frequency of extreme El Niño and La Niña events over the twenty-first century are confirmed, then populated regions on opposite sides of the Pacific Ocean basin could be alternately exposed to extreme coastal erosion and flooding, independent of sea-level rise.

Identifying water price and population criteria for meeting future urban water demand targets

NASA Astrophysics Data System (ADS)

Ashoori, Negin; Dzombak, David A.; Small, Mitchell J.

2017-12-01

Predictive models for urban water demand can help identify the set of factors that must be satisfied in order to meet future targets for water demand. Some of the explanatory variables used in such models, such as service area population and changing temperature and rainfall rates, are outside the immediate control of water planners and managers. Others, such as water pricing and the intensity of voluntary water conservation efforts, are subject to decisions and programs implemented by the water utility. In order to understand this relationship, a multiple regression model fit to 44 years of monthly demand data (1970-2014) for Los Angeles, California was applied to predict possible future demand through 2050 under alternative scenarios for the explanatory variables: population, price, voluntary conservation efforts, and temperature and precipitation outcomes predicted by four global climate models with two CO2 emission scenarios. Future residential water demand in Los Angeles is projected to be largely driven by price and population rather than climate change and conservation. A median projection for the year 2050 indicates that residential water demand in Los Angeles will increase by approximately 36 percent, to a level of 620 million m3 per year. The Monte Carlo simulations of the fitted model for water demand were then used to find the set of conditions in the future for which water demand is predicted to be above or below the Los Angeles Department of Water and Power 2035 goal to reduce residential water demand by 25%. Results indicate that increases in price can not ensure that the 2035 water demand target can be met when population increases. Los Angeles must rely on furthering their conservation initiatives and increasing their use of stormwater capture, recycled water, and expanding their groundwater storage. The forecasting approach developed in this study can be utilized by other cities to understand the future of water demand in water-stressed areas. Improving water demand forecasts will help planners understand and optimize future investments in water supply infrastructure and related programs.

Water Quality and Hydrology of Whitefish (Bardon) Lake, Douglas County, Wisconsin, With Special Emphasis on Responses of an Oligotrophic Seepage Lake to Changes in Phosphorus Loading and Water Level

USGS Publications Warehouse

Robertson, Dale M.; Rose, William J.; Juckem, Paul F.

2009-01-01

Whitefish Lake, which is officially named Bardon Lake, is an oligotrophic, soft-water seepage lake in northwestern Wisconsin, and classified by the Wisconsin Department of Natural Resources as an Outstanding Resource Water. Ongoing monitoring of the lake demonstrated that its water quality began to degrade (increased phosphorus and chlorophyll a concentrations) around 2002 following a period of high water level. To provide a better understanding of what caused the degradation in water quality, and provide information to better understand the lake and protect it from future degradation, the U.S. Geological Survey did a detailed study from 2004 to 2008. The goals of the study were to describe the past and present water quality of the lake, quantify water and phosphorus budgets for the lake, simulate the potential effects of changes in phosphorus inputs on the lake's water quality, analyze changes in the water level in the lake since 1900, and relate the importance of changes in climate and changes in anthropogenic (human-induced) factors in the watershed to the water quality of the lake. Since 1998, total phosphorus concentrations increased from near the 0.005-milligrams per liter (mg/L) detection limit to about 0.010 mg/L in 2006, and then decreased slightly in 2007-08. During this time, chlorophyll a concentrations and Secchi depths remained relatively stable at about 1.5 micrograms per liter (ug/L) and 26 feet, respectively. Whitefish Lake is typically classified as oligotrophic. Because the productivity in Whitefish Lake is limited by phosphorus, phosphorus budgets were constructed for the lake. Because it was believed that much of its phosphorus comes from the atmosphere, phosphorus deposition was measured in this study. Phosphorus input from the atmosphere was greater than computed based on previously reported wetfall phosphorus concentrations. The concentrations and deposition rates can be used to estimate atmospheric loading in future lake studies. The average annual load of phosphorus to the lake was 232 pounds: 56 percent from precipitation, 27 percent from groundwater, and 16 percent from septic systems. During a series of dry years (low water levels) and wet years (high water levels), the inputs of water and phosphorus ranged by only 10-13 percent. Results from the Canfield and Bachmann eutrophication model and Carlson trophic-state-index equations demonstrated that the lake directly responds to changes in external phosphorus loading, with percent change in chlorophyll a being similar to the percent change in loading and the change in total phosphorus and Secchi depth being slightly smaller. Therefore, changes in phosphorus loading should affect the water quality of the lake. Specific scenarios that simulated the effects of anthropogenic (human-induced) and climatic (water level) changes demonstrated that: surface-water inflow (runoff) based on current development has little effect on pelagic water quality, changes in the inputs from septic systems and development in the watershed could have a large effect on water quality, and decreases in water and phosphorus loading during periods of low water level had little effect on water quality. Sustained high water levels, resulting from several wet years with relatively high water and phosphorus input, however, could cause a small degradation in water quality. Although high water levels may be associated with a degradation in water quality, it appears that anthropogenic changes in the watershed may be more important in affecting the future water quality of the lake. Fluctuations in water levels since 1998 are representative of what has occurred since 1900, with fluctuations of about 3 feet occurring about every 15 years. Based on total phosphorus concentrations inferred from sediment core analysis, there has been little long-term change in water quality and there has been a slight deterioration in water quality following most periods of high water levels. There

Projections of Water Stress Based on an Ensemble of Socioeconomic Growth and Climate Change Scenarios: A Case Study in Asia.

PubMed

Fant, Charles; Schlosser, C Adam; Gao, Xiang; Strzepek, Kenneth; Reilly, John

2016-01-01

The sustainability of future water resources is of paramount importance and is affected by many factors, including population, wealth and climate. Inherent in current methods to estimate these factors in the future is the uncertainty of their prediction. In this study, we integrate a large ensemble of scenarios--internally consistent across economics, emissions, climate, and population--to develop a risk portfolio of water stress over a large portion of Asia that includes China, India, and Mainland Southeast Asia in a future with unconstrained emissions. We isolate the effects of socioeconomic growth from the effects of climate change in order to identify the primary drivers of stress on water resources. We find that water needs related to socioeconomic changes, which are currently small, are likely to increase considerably in the future, often overshadowing the effect of climate change on levels of water stress. As a result, there is a high risk of severe water stress in densely populated watersheds by 2050, compared to recent history. There is strong evidence to suggest that, in the absence of autonomous adaptation or societal response, a much larger portion of the region's population will live in water-stressed regions in the near future. Tools and studies such as these can effectively investigate large-scale system sensitivities and can be useful in engaging and informing decision makers.

Projections of Water Stress Based on an Ensemble of Socioeconomic Growth and Climate Change Scenarios: A Case Study in Asia

PubMed Central

Fant, Charles; Schlosser, C. Adam; Gao, Xiang; Strzepek, Kenneth; Reilly, John

2016-01-01

The sustainability of future water resources is of paramount importance and is affected by many factors, including population, wealth and climate. Inherent in current methods to estimate these factors in the future is the uncertainty of their prediction. In this study, we integrate a large ensemble of scenarios—internally consistent across economics, emissions, climate, and population—to develop a risk portfolio of water stress over a large portion of Asia that includes China, India, and Mainland Southeast Asia in a future with unconstrained emissions. We isolate the effects of socioeconomic growth from the effects of climate change in order to identify the primary drivers of stress on water resources. We find that water needs related to socioeconomic changes, which are currently small, are likely to increase considerably in the future, often overshadowing the effect of climate change on levels of water stress. As a result, there is a high risk of severe water stress in densely populated watersheds by 2050, compared to recent history. There is strong evidence to suggest that, in the absence of autonomous adaptation or societal response, a much larger portion of the region’s population will live in water-stressed regions in the near future. Tools and studies such as these can effectively investigate large-scale system sensitivities and can be useful in engaging and informing decision makers. PMID:27028871

Modelling the water energy nexus: should variability in water supply impact on decision making for future energy supply options?

NASA Astrophysics Data System (ADS)

Cullis, James D. S.; Walker, Nicholas J.; Ahjum, Fadiel; Juan Rodriguez, Diego

2018-02-01

Many countries, like South Africa, Australia, India, China and the United States, are highly dependent on coal fired power stations for energy generation. These power stations require significant amounts of water, particularly when fitted with technology to reduce pollution and climate change impacts. As water resources come under stress it is important that spatial variability in water availability is taken into consideration for future energy planning particularly with regards to motivating for a switch from coal fired power stations to renewable technologies. This is particularly true in developing countries where there is a need for increased power production and associated increasing water demands for energy. Typically future energy supply options are modelled using a least cost optimization model such as TIMES that considers water supply as an input cost, but is generally constant for all technologies. Different energy technologies are located in different regions of the country with different levels of water availability and associated infrastructure development and supply costs. In this study we develop marginal cost curves for future water supply options in different regions of a country where different energy technologies are planned for development. These water supply cost curves are then used in an expanded version of the South Africa TIMES model called SATIM-W that explicitly models the water-energy nexus by taking into account the regional nature of water supply availability associated with different energy supply technologies. The results show a significant difference in the optimal future energy mix and in particular an increase in renewables and a demand for dry-cooling technologies that would not have been the case if the regional variability of water availability had not been taken into account. Choices in energy policy, such as the introduction of a carbon tax, will also significantly impact on future water resources, placing additional water demands in some regions and making water available for other users in other regions with a declining future energy demand. This study presents a methodology for modelling the water-energy nexus that could be used to inform the sustainable development planning process in the water and energy sectors for both developed and developing countries.

Regulation of water resources for sustaining global future socioeconomic development

NASA Astrophysics Data System (ADS)

Chen, J.; SHI, H.; Sivakumar, B.

2016-12-01

With population projections indicating continued growth during this century, socio-economic problems (e.g., water, food, and energy shortages) will be most likely to occur, especially if proper planning, development, and management strategies are not adopted. In the present study, firstly, we explore the vital role of dams in promoting economic growth through analyzing the relationship between dams and Gross Domestic Product (GDP) at both global and national scales. Secondly, we analyze the current situation of global water scarcity based on the data representing water resources availability, dam development, and the level of economic development. Third, with comprehensive consideration of population growth as the major driving force, water resources availability as the basic supporting factor, and topography as the important constraint, this study addresses the question of dam development in the future and predicts the locations of future dams around the world.

Multi-model and multi-scenario assessments of Asian water futures: The Water Futures and Solutions (WFaS) initiative

NASA Astrophysics Data System (ADS)

Satoh, Yusuke; Kahil, Taher; Byers, Edward; Burek, Peter; Fischer, Günther; Tramberend, Sylvia; Greve, Peter; Flörke, Martina; Eisner, Stephanie; Hanasaki, Naota; Magnuszewski, Piotr; Nava, Luzma Fabiola; Cosgrove, William; Langan, Simon; Wada, Yoshihide

2017-07-01

This paper presents one of the first quantitative scenario assessments for future water supply and demand in Asia to 2050. The assessment, developed by the Water Futures and Solutions (WFaS) initiative, uses the latest set of global climate change and socioeconomic scenarios and state-of-the-art global hydrological models. In Asia, water demand for irrigation, industry, and households is projected to increase substantially in the coming decades (30-40% by 2050 compared to 2010). These changes are expected to exacerbate water stress, especially in the current hotspots such as north India and Pakistan, and north China. By 2050, 20% of the land area in the Asia-Pacific region, with a population of 1.6-2 billion, is projected to experience severe water stress. We find that socioeconomic changes are the main drivers of worsening water scarcity in Asia, with climate change impacts further increasing the challenge into the 21st century. Moreover, a detailed basin-level analysis of the hydro-economic conditions of 40 Asian basins shows that although the coping capacity of all basins is expected to improve due to gross domestic product (GDP) growth, some basins continuously face severe water challenges. These basins will potentially be home to up to 1.6 billion people by mid-21st century.

Role of production intensification on water use efficiency in catfish pond aquaculture

USDA-ARS?s Scientific Manuscript database

Availability of fresh water is sometimes considered to be a limiting factor for future aquaculture development. This is certainly true at specific local levels where aquaculture may conflict with other water uses. A good example is the Yazoo-Mississippi River floodplain in northwest Mississippi, whe...

A review of water use in the U.S. electric power sector: insights from systems-level perspectives

EPA Science Inventory

Thermoelectric power production comprised 41% of total freshwater withdrawals in the U.S., surpassing even agriculture. This review highlights scenarios of the electric sector’s future demands for water, including scenarios that limit both CO2 and water availability. A number o...

Global Water Resources Under Future Changes: Toward an Improved Estimation

NASA Astrophysics Data System (ADS)

Islam, M.; Agata, Y.; Hanasaki, N.; Kanae, S.; Oki, T.

2005-05-01

Global water resources availability in the 21st century is going to be an important concern. Despite its international recognition, however, until now there are very limited global estimates of water resources, which considered the geographical linkage between water supply and demand, defined by runoff and its passage through river network. The available studies are again insufficient due to reasons like different approaches in defining water scarcity, simply based on annual average figures without considering the inter-annual or seasonal variability, absence of the inclusion of virtual water trading, etc. In this study, global water resources under future climate change associated with several socio-economic factors were estimated varying over both temporal and spatial scale. Global runoff data was derived from several land surface models under the GSWP2 (Global Soil Wetness Project) project, which was further processed through TRIP (Total Runoff Integrated Pathways) river routing model to produce a 0.5x0.5 degree grid based figure. Water abstraction was estimated for the same spatial resolution for three sectors as domestic, industrial and agriculture. GCM outputs from CCSR and MRI were collected to predict the runoff changes. Socio-economic factors like population and GDP growth, affected mostly the demand part. Instead of simply looking at annual figures, monthly figures for both supply and demand was considered. For an average year, such a seasonal variability can affect the crop yield significantly. In other case, inter-annual variability of runoff can cause for an absolute drought condition. To account for vulnerabilities of a region to future changes, both inter-annual and seasonal effects were thus considered. At present, the study assumed the future agricultural water uses to be unchanged under climatic changes. In this connection, EPIC model is underway to use for estimating future agricultural water demand under climatic changes on a monthly basis. From the estimation of present stress level (withdrawal to resource ratio), the months between January to May was found to have the highest number of population above water stress level, while the months between June to August having lower population in stress. The regions suffering from high seasonal variability are those of Asian monsoon zone, south-central Africa and central-east part of South America. Inter-annual variability, on the other hand, is dominant mostly along the Middle-east or Sahara regions and the western part of South America and Latin America. Virtual water trading among countries was estimated on per capita basis. It shows that many Middle east countries are able to compensate their water stress significantly through virtual water trading. The overall effect of climate change on lowering of river runoff mostly affected Europe, southern part of China and Latin America. India or Central Africa have better runoff availability under changing climate, but still subject to a higher water stress because of socio-economic factors like high population growth and expected increase in rate of water uses. Decrease in population as well as saturation level of maximum water uses along most European countries, on the contrary, relaxed the pressure of lowering river runoff, causing no significant change in future stress.

Present and future water resources supply and demand in the Central Andes of Peru: a comprehensive review with focus on the Cordillera Vilcanota

NASA Astrophysics Data System (ADS)

Drenkhan, Fabian; Huggel, Christian; Salzmann, Nadine; Giráldez, Claudia; Suarez, Wilson; Rohrer, Mario; Molina, Edwin; Montoya, Nilton; Miñan, Fiorella

2014-05-01

Glaciers have been an important element of Andean societies and livelihoods as direct freshwater supply for agriculture irrigation, hydropower generation and mining activities. Peru's mainly remotely living population in the Central Andes has to cope with a strong seasonal variation of precipitations and river runoff interannually superimposed by El Niño impacts. Direct glacier and lake water discharge thus constitute a vital continuous water supply and represent a regulating buffer as far as hydrological variability is concerned. This crucial buffer effect is gradually altered by accelerated glacier retreat which leads most likely to an increase of annual river runoff variability. Furthermore, a near-future crossing of the 'peak water' is expected, from where on prior enhanced streamflow decreases and levels out towards a new still unknown minimum discharge. Consequently, a sustainable future water supply especially during low-level runoff dry season might not be guaranteed whereas Peru's water demand increases significantly. Here we present a comprehensive review, the current conditions and perspectives for water resources in the Cusco area with focus on the Vilcanota River, Cordillera Vilcanota, Southern Peru. With 279 km2 the Cordillera Vilcanota represents the second largest glacierized mountain range of the tropics worldwide. Especially as of the second half of the 1980s, it has been strongly affected by massive ice loss with around 30% glacier area decline until present. Furthermore, glacier vanishing triggers the formation of new lakes and increase of lake levels and therefore constitutes determining hazardous drivers for mass movements related to deglaciation effects. The Vilcanota River still lacks more profound hydrological studies. It is likely that its peak water has already been or might be crossed in near-future. This has strong implications for the still at 0.9% (2.2%) annually growing population of the Cusco department (Cusco city). People mostly depend on these water resources but indicate a strong water vulnerability due to a high degree of absolute poverty, 30% and only 67% of access to drinking water. The Vilcanota area has been traditionally the breadbasket for the whole Cusco area. While agriculture is the most important labor sector, a growing export-oriented crop production depends highly on a minimum river streamflow ensuring sufficient water quantity and quality. Hydropower, with 53% of the total electricity nationwide the energy pillar of Peru's economy, might also be heavily affected by diminishing water resources. Nevertheless, improved power plants have to balance out Peru's by 7.5% y-1 increasing energy demand. For instance, the Machu Picchu hydropower plant is currently expanded by 100 MW to a full capacity of 190 MW but does not consider future water availability of the Vilcanota River and local impacts for the population. Our conclusions suggest to focus on an integrative risk-oriented supply-demand water balance model scheme in order to capture the complexity of recent and future water distribution. The integration of both physical and social key variables considering long-term changes in climate-glacier interactions as well as economic and demographic trends, plays a determinant role for the performance quality of that model and future adaptation strategies.

Monitoring Everglades freshwater marsh water level using L-band synthetic aperture radar backscatter

USGS Publications Warehouse

Kim, Jin-Woo; Lu, Zhong; Jones, John W.; Shum, C.K.; Lee, Hyongki; Jia, Yuanyuan

2014-01-01

The Florida Everglades plays a significant role in controlling floods, improving water quality, supporting ecosystems, and maintaining biodiversity in south Florida. Adaptive restoration and management of the Everglades requires the best information possible regarding wetland hydrology. We developed a new and innovative approach to quantify spatial and temporal variations in wetland water levels within the Everglades, Florida. We observed high correlations between water level measured at in situ gages and L-band SAR backscatter coefficients in the freshwater marsh, though C-band SAR backscatter has no close relationship with water level. Here we illustrate the complementarity of SAR backscatter coefficient differencing and interferometry (InSAR) for improved estimation of high spatial resolution water level variations in the Everglades. This technique has a certain limitation in applying to swamp forests with dense vegetation cover, but we conclude that this new method is promising in future applications to wetland hydrology research.

Increasing extreme water level flood risk as a result of future sea-level rise: A case study on a coastal city in China

NASA Astrophysics Data System (ADS)

Feng, A.; Wu, S.

2016-12-01

Extreme water levels, caused by the joint occurrence of storm surges and high tides, always lead to super floods along coastlines. In the context of climate change, this study explored the impact of future sea-level rise on the flood risk of extreme water levels. Using Rongcheng City in Shandong Province, China as a case study, flooded area, expected direct damage losses, and affected population and GDP were assessed for 2050 and 2100 under three greenhouse gas concentration Representative Concentration Pathways (RCP) scenarios, 2.6, 4.5, and 8.5. Results indicate that, as a result of sea-level rise induced by climate change, the flooded areas of Rongcheng City would increase by 3.23% to 10.64% in 2050 and by as much as 4.98% to 19.87% in 2100, compared with current recurrence periods. Residential land and farmland are at greatest risk of flooding in terms of exposure and losses than other land-use types, and under a high degree RCP 8.5 scenario, expected damage losses would be between 59.84 billion and 86.45 billion in 2050. Results show that the increase in total direct damage losses would reach an average of 60% in 2100 as a result of a 0.82 m sea-level rise. Similarly, affected population and GDP would increase by between 4.95% and 13.87% and between 3.66% and 10.95% in 2050, and by as much as 7.69% to 29.01% and 5.30% to 20.50% in 2100. This study shows that sea-level rise significantly shortens recurrence periods of extreme water levels, makes extreme flood events more frequent, and exacerbates the risk of future flooding. Our results suggest that, if there is no adaptation, sea-level rise will greatly increase the risk of flooding and severely impact human habitability along coastlines.

Coupled Atmosphere-Surface Modeling of Lake Levels of the North American Great Lakes under Climate Change

NASA Astrophysics Data System (ADS)

Lofgren, B. M.; Xiao, C.

2016-12-01

The influence of projected climate change on the water levels of the Great Lakes is subject to considerable uncertainty, and methods that have long been used to determine this sensitivity have been discredited. A strong candidate, albeit expensive, to replace problematic methods is to use outputs that result from dynamical downscaling of future climate simulations, focused on the hydroclimate of the Great Lakes basin. We have produced initial estimates of Great Lakes water levels in the mid- and late 21st century using the Weather Research and Forecasting (WRF) model, including its lake module, driven by lateral boundary conditions from the Geophysical Fluid Dynamics Lab Climate Model version 3.0 (GFDL CM3), under RCP4.5 and 8.5 scenarios. Future lake levels are influenced by the balance between projected general increases in precipitation and increases in evapotranspiration from both land and lake in the basin, driven primarily by the surface radiative energy budget and secondarily by air temperature. The net result was drops in lake level of up to 15 cm, in contrast to the results from much-used older methods, which often projected drops exceeding 1 m. Future plans include increased detail in the simulation of water flow overland and in river channels using WRF-Hydro, and full coupling of regional atmospheric systems with 3-dimensional dynamical lake implementation of the Finite Volume Community Ocean Model (FVCOM).

Current (2004-07) Conditions and Changes in Ground-Water Levels from Predevelopment to 2007, Southern High Plains Aquifer, Southeast New Mexico-Lea County Underground Water Basin

USGS Publications Warehouse

Tillery, Anne

2008-01-01

The Southern High Plains aquifer is the principal aquifer and primary source of water in southeastern New Mexico. The Lea County portion of the aquifer covers approximately the northern two thirds of the 4,393-square-mile county. Successful water-supply planning for New Mexico's Southern High Plains requires knowledge of the current aquifer conditions and a context from which to estimate future trends given current aquifer-management policy. Maps representing water-level declines, current (2007) water levels, aquifer saturated thickness, and depth to water accompanied by hydrographs from representative wells for the Southern High Plains aquifer in the Lea County Underground Water Basin were prepared in cooperation with the New Mexico Office of the State Engineer. Results of this mapping effort show the water level has declined as much as 97 feet in the Lea County Underground Water Basin from predevelopment (1914-54) to 2007 with rates as high as 0.88 feet per year.

Analysis of Tests of Subsurface Injection, Storage, and Recovery of Freshwater in Lancaster, Antelope Valley, California

USGS Publications Warehouse

Phillips, Steven P.; Carlson, Carl S.; Metzger, Loren F.; Howle, James F.; Galloway, Devin L.; Sneed, Michelle; Ikehara, Marti E.; Hudnut, Kenneth W.; King, Nancy E.

2003-01-01

Ground-water levels in Lancaster, California, declined more than 200 feet during the 20th century, resulting in reduced ground-water supplies and more than 6 feet of land subsidence. Facing continuing population growth, water managers are seeking solutions to these problems. Injection of imported, treated fresh water into the aquifer system when it is most available and least expensive, for later use during high-demand periods, is being evaluated as part of a management solution. The U.S. Geological Survey, in cooperation with the Los Angeles County Department of Public Works and the Antelope Valley-East Kern Water Agency, monitored a pilot injection program, analyzed the hydraulic and subsidence-related effects of injection, and developed a simulation/optimization model to help evaluate the effectiveness of using existing and proposed wells in an injection program for halting the decline of ground-water levels and avoiding future land subsidence while meeting increasing ground-water demand. A variety of methods were used to measure aquifer-system response to injection. Water levels were measured continuously in nested (multi-depth) piezometers and monitoring wells and periodically in other wells that were within several miles of the injection site. Microgravity surveys were done to estimate changes in the elevation of the water table in the absence of wells and to estimate specific yield. Aquifer-system deformation was measured directly and continuously using a dual borehole extensometer and indirectly using continuous Global Positioning System (GPS), first-order spirit leveling, and an array of tiltmeters. The injected water and extracted water were sampled periodically and analyzed for constituents, including chloride and trihalomethanes. Measured injection rates of about 750 gallons per minute (gal/min) per well at the injection site during a 5-month period showed that injection at or above the average extraction rates at that site (about 800 gal/min) was hydraulically feasible. Analyses of these data took many forms. Coupled measurements of gravity and water-level change were used to estimate the specific yield near the injection wells, which, in turn, was used to estimate areal water-table changes from distributed measurements of gravity change. Values of the skeletal components of aquifer-system storage, which are key subsidence-related characteristics of the system, were derived from continuous measurements of water levels and aquifer-system deformation. A numerical model of ground-water flow was developed for the area surrounding Lancaster and used to estimate horizontal and vertical hydraulic conductivities. A chemical mass balance was done to estimate the recovery of injected water. The ground-water-flow model was used to project changes in ground-water levels for 10 years into the future, assuming no injection, no change in pumping distribution, and forecasted increases in ground-water demand. Simulated ground-water levels decreased throughout the Lancaster area, suggesting that land subsidence would continue as would the depletion of ground-water supplies and an associated loss of well production capacity. A simulation/optimization model was developed to help identify optimal injection and extraction rates for 16 existing and 13 proposed wells to avoid future land subsidence and to minimize loss of well production capacity while meeting increasing ground-water demands. Results of model simulations suggest that these objectives can be met with phased installation of the proposed wells during the 10-year period. Water quality was not considered in the optimization, but chemical-mass-balance results indicate that a sustained injection program likely would have residual effects on the chemistry of ground water.

Current and future groundwater withdrawals: Effects, management and energy policy options for a semi-arid Indian watershed

NASA Astrophysics Data System (ADS)

Sishodia, Rajendra P.; Shukla, Sanjay; Graham, Wendy D.; Wani, Suhas P.; Jones, James W.; Heaney, James

2017-12-01

Effects of future expansion/intensification of irrigated agriculture on groundwater and surface water levels and availability in a semi-arid watershed were evaluated using an integrated hydrologic model (MIKE SHE/MIKE 11) in conjunction with biophysical measurements. Improved water use efficiency, water storage, and energy policy options were evaluated for their ability to sustain the future (2035) increased groundwater withdrawals. Three future withdrawal scenarios (low = 20, medium = 30, high = 50 wells/100 km2/year) based on the historical rate of growth of irrigation wells were formulated. While well drying from falling groundwater levels was limited to drought and consecutive below average rainfall years, under the current (2015) withdrawals, significant increases in frequency and duration (17-97 days/year) of well drying along with 13-26% (19-37 mm) reductions in surface flows were predicted under the future withdrawals. Higher (27-108%) energy demands of existing irrigation pumps due to declining groundwater levels and reduced hydroelectric generation due to decreased surface flows would create a vicious water-food-energy nexus in the future. Crop failure, one of the main causes of farmers' emotional distress and death in the region, is predicted to exacerbate under the future withdrawal scenarios. Shift to negative net recharge (-63 mm) and early and prolonged drying of wells under the high scenario will reduce the groundwater availability and negatively affect crop production in more than 60% and 90% of cropped areas in the Rabi (November-February) and summer (March-May) seasons, respectively during a drought year. Individual and combined demand (drip irrigation and reduced farm electricity subsidy) and supply (water storage) management options improved groundwater levels and reduced well drying by 55-97 days/year compared to business-as-usual management under the high scenario. The combined management (50% drip conversion, 50% reduction in subsidy, and enhanced water storage) mitigated well drying even during drought and consecutive below average rainfall years under the high scenario. A conservative economic evaluation for management options under the high scenario showed increases in crop production and per farmer annual profits by 987-1397 during a drought year (average household income = 1520/year). A scale-up of results showed that diverting 50% state power subsidy (6 billion for 3-6 years) can almost entirely fund the conversion to drip irrigation (4.2 billion) and water storage structures (2.9 billion) and help meet the water supply demand of a 50% increase in irrigated area under the high scenario. Converting flood to drip irrigation in 50% of irrigated area under the high scenario can reduce the electric energy consumption (7 × 106Mwh/year) and carbon footprint (6000 Mt/year) of groundwater irrigation by 24% in the state. Management options considered can potentially create a sustainable water-food-energy nexus in the larger semi-arid hard rock region. Reducing the power subsidy will require a strong political will since it has been used as a tool to win the elections in India. Considering future agricultural intensification, timely interventions are needed to ensure the livelihood and well-being of millions of small- and medium-scale farmers that rely on low storage, hard rock aquifers in the semi-arid regions of the world.

Institutional and socioeconomic aspects of water supply

NASA Astrophysics Data System (ADS)

Rauchenschwandtner, H.; Pachel, M.

2012-04-01

Institutional and socioeconomic aspects of water supply Within the project CC-WaterS the participating researchers of the Vienna University of Economics and B.A. have been responsible for the analysis of the socioeconomic aspects related to water supply and climate change, the assessment of future water demands in the City of Vienna, as well as an estimation of economic consequences of possible water shortages and possible scope for the introduction of new legal guidelines. The institutional and socioeconomic dimensions of drinking water and sanitation systems are being examined by utilisation of different prognostic scenarios in order to assess future costs of water provisioning and future demands of main water users, thus providing an information basis and recommendations for policy and decision makers in the water sector. These dimensions, for example, include EU legislation - especially the Water Framework Directive -, national legislations and strategies targeted at achieving sustainability in water usage, best practices and different forms of regulating water markets, and an analysis of the implications of demographic change. As a basis this task encompasses research of given institutional, social, and legal-political structures in the area of water supply. In this course we provide an analysis of the structural characteristics of water markets, the role of water prices, the increasing perception of water as an economic good as well as implications thereof, the public awareness in regard to climate change and water resources, as well as related legal aspects and involved actors from regional to international level; and show how water resources and the different systems of water provisioning are affected by (ideological) conflicts on various levels. Furthermore, and in order to provide a solid basis for management recommendations related to climate change and water supply, an analytical risk-assessment framework based on the concepts of new institutional economics is being developed, which provides a different analytical perspective for examining the linkages between institutions, economic processes, and societal factors.

Parametric Analysis of Life Support Systems for Future Space Exploration Missions

NASA Technical Reports Server (NTRS)

Swickrath, Michael J.; Anderson, Molly S.; Bagdigian, Bob M.

2011-01-01

The National Aeronautics and Space Administration is in a process of evaluating future targets for space exploration. In order to maintain the welfare of a crew during future missions, a suite of life support technology is responsible for oxygen and water generation, carbon dioxide control, the removal of trace concentrations of organic contaminants, processing and recovery of water, and the storage and reclamation of solid waste. For each particular life support subsystem, a variety competing technologies either exist or are under aggressive development efforts. Each individual technology has strengths and weaknesses with regard to launch mass, power and cooling requirements, volume of hardware and consumables, and crew time requirements for operation. However, from a system level perspective, the favorability of each life support architecture is better assessed when the sub-system technologies are analyzed in aggregate. In order to evaluate each specific life support system architecture, the measure of equivalent system mass (ESM) was employed to benchmark system favorability. Moreover, the results discussed herein will be from the context of loop-closure with respect to the air, water, and waste sub-systems. Specifically, closure relates to the amount of consumables mass that crosses the boundary of the vehicle over the lifetime of a mission. As will be demonstrated in this manuscript, the optimal level of loop closure is heavily dependent upon mission requirements such as duration and the level of extra-vehicular activity (EVA) performed. Sub-system level trades were also considered as a function of mission duration to assess when increased loop closure is practical. Although many additional factors will likely merit consideration in designing life support systems for future missions, the ESM results described herein provide a context for future architecture design decisions toward a flexible path program.

Regional hydrology and simulation of deep ground-water flow in the Southeastern Coastal Plain aquifer system in Mississippi, Alabama, Georgia, and South Carolina

USGS Publications Warehouse

Barker, R.A.; Pernik, Maribeth

1994-01-01

The Southeastern Coastal Plain aquifer system is a coastward-sloping, wedge-shaped sand and gravel reservoir exposed in outcrop to a humid climate and drained by an extensive surface-water network. Ground-water pumpage has increased to about 765 cubic feet per second since 1900, causing water-level declines of more than 150 feet in places, while base flow to major streams has decreased about 350 cubic feet per second. The water-level declines and adjustments in recharge and discharge are not expected to seriously restrict future ground-water development.

7 CFR 14.6 - Criteria for determining the pri- mary purpose of payments with respect to potential exclusion...

Code of Federal Regulations, 2010 CFR

2010-01-01

... conservation includes actions that, for a given level of water supply, reduce the demand for or use of water by... reuse of water, thereby making existing supplies available for other current or future uses; or (iv) Improving land management practices for the purpose of reducing water use, loss, waste, increasing the...

Risk to Water Security on Small Islands

NASA Astrophysics Data System (ADS)

Holding, S. T.; Allen, D. M.

2013-12-01

The majority of fresh water available on small islands is shallow groundwater that forms a freshwater lens. Freshwater lenses are generally limited in extent and as such are vulnerable to many stressors that impact water security. These include stressors related to climate change, such as sea level rise, as well as those related to human impacts, such as contamination. Traditionally, water security assessments have focussed on indicators that provide a snapshot of the current condition. However, recent work suggests that in order to effectively manage the water system, it is also important to consider uncertain future impacts to the system by evaluating how different stressors might impact water security. In this study, a framework for assessing risk to water security was developed and tested on Andros Island in The Bahamas. The assessment comprises two main components that characterise the water system: numerical modelling studies and a hazard survey. A baseline numerical model of the freshwater lens throughout Andros Island was developed to simulate the morphology of the freshwater lens and estimate the freshwater resources currently available. The model was prepared using SEAWAT, a density-dependent flow and solute transport code. Various stressors were simulated in the model to evaluate the response of the freshwater lens to predicted future shifts in climate patterns, sea level rise, and changes in water use. A hazard survey was also conducted on the island to collect information related to the storage of contaminants, sanitation infrastructure, waste disposal practices and groundwater abstraction rates. The results of the survey form a geo-spatial database of the location and associated hazards to the freshwater lens. The resulting risk framework provides a ranking of overall risk to water security based on information from the numerical modelling and hazard survey. The risk framework is implemented in a Geographic Information System (GIS) and provides a map of the risk to water security throughout Andros Island. It evaluates risk to water security for current and future scenarios and will enable water resource managers to effectively adapt to future impacts on water security.

Public participation in water resources management: Restructuring model of upstream Musi watershed

NASA Astrophysics Data System (ADS)

Andriani, Yuli; Zagloel, T. Yuri M.; Koestoer, R. H.; Suparmoko, M.

2017-11-01

Water is the source of life needed by living things. Human as one of living most in needs of water. Because the population growth follows the geometrical progression, while the natural resource increases calculates the arithmetic. Humans besides needing water also need land for shelter and for their livelihood needs, such as gardening or rice farmers. If the water absorption area is reduced, water availability will decrease. Therefore it is necessary to conduct an in-depth study of water resources management involving the community. The purpose of this study is to analyze community participation in water resources management, so that its availability can still meet the needs of living and sustainable. The method that used the level of community participation according to Arstein theory. The results obtained that community participation is at the level of partnership and power delegation. This level of participation is at the level of participation that determines the sustainability of water resources for present and future generations.

Past, Present, and Future Sea Level Change Assessments of Storm Surge: A Case Study Using Hurricane Katrina

NASA Astrophysics Data System (ADS)

Bilskie, M. V.; Medeiros, S. C.; Hagen, S. C.

2012-12-01

Major Gulf hurricanes have a high probability of impacting the northern Gulf of Mexico, especially coastal Mississippi (Resio, 2007). Due to the wide and flat continental shelf, this area provides near-perfect geometry for high water levels under tropical cyclonic conditions. Further, it is generally agreed that global sea levels due to climate change will rise anywhere from 18 to 100 cm by the year 2100 (Donoghue, 2011, IPCC, 2007) with some projecting even higher. Further, it is recognized that coastal Mississippi is highly susceptible to a retreating shoreline from sea level rise coupled with predictions for less frequent, more intense tropical storms from an increase in sea surface temperature (SST) (Trenberth, 2005, Webster, et al., 2005). A fully-validated, state-of-the-art ADCIRC+UnSWAN hydrodynamic model of coastal Mississippi was utilized to simulate Hurricane Katrina with present day sea level conditions. Using present day as a base scenario, past and future sea level changes were simulated. A regression was performed at local tide gauges to estimate past and project future sea levels. Also, surface roughness (i.e. Manning's n and wind reduction factors) was adjusted to reflect past landcover conditions as well as estimate future landcover change. Here, past, present and future sea level scenarios are modeled using a dynamic approach, along with Hurricane Katrina, and compared to present dynamic responses to sea level rise. The dynamic results will be compared and contrasted with a simpler bathtub model (static) approach. It will be demonstrated that water levels do not change linearly with modeled sea level cases (i.e. a 50 cm rise in sea level will not result in an additional 50 cm of water level at a given location) and are highly variable to changes in local conditions (e.g. topography, bathymetry, and surface roughness). Further, nearshore wind-wave conditions are affected by changes in local sea level due to the changes in momentum transfer from the waves to the water column. The results will be used to gain insight into possible morphological changes given several sea level scenarios coupled with an intense tropical cyclone. References Donoghue, J. (2011). "Sea Level History of the Northern Gulf of Mexico Coast and Sea Level Rise Scenarios for the near Future." Climatic Change, 107(1-2), 17-33. IPCC (2007). "The Physical Sceince Basis, Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change." Climate Change 2007, S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K. B. Avery, M. Tignor, and H. L. Miller, eds., Cambridge Univesity Press, Cambridge. Resio, D. T. (2007). "White Paper on Estimating Hurricane Inundation Probabilities." U.S. Army Engineering Research and Development Center, Vicksburg, MS, 125. Trenberth, K. (2005). "Uncertainty in Hurricanes and Global Warming." Science, 308(5729), 1753-1754. Webster, P. J., Holland, G. J., Curry, J. A., and Chang, H.-R. (2005). "Changes in Tropical Cyclone Number, Duration, and Intensity in a Warming Environment." Science, 309(5742), 1844-1846.

Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply

USGS Publications Warehouse

Ganju, N.K.; Schoellhamer, D.H.

2010-01-01

Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological hydrograph concept and the morphological acceleration factor. The four scenarios included (1) present-day conditions; (2) sea-level rise and freshwater flow changes of 2030; (3) sea-level rise and decreased watershed sediment supply of 2030; and (4) sea-level rise, freshwater flow changes, and decreased watershed sediment supply of 2030. Sea-level rise increased water levels thereby reducing wave-induced bottom shear stress and sediment redistribution during the wind-wave season. Decreased watershed sediment supply reduced net deposition within the estuary, while minor changes in freshwater flow timing and magnitude induced the smallest overall effect. In all future scenarios, net deposition in the entire estuary and in the shallowest areas did not keep pace with sea-level rise, suggesting that intertidal and wetland areas may struggle to maintain elevation. Tidal-timescale simulations using future conditions were also used to infer changes in optical depth: though sea-level rise acts to decrease mean light irradiance, decreased suspended-sediment concentrations increase irradiance, yielding small changes in optical depth. The modeling results also assisted with the development of a dimensionless estuarine geomorphic number representing the ratio of potential sediment import forces to sediment export forces; we found the number to be linearly related to relative geomorphic change in Suisun Bay. The methods implemented here are widely applicable to evaluating future scenarios of estuarine change over decadal timescales. ?? The Author(s) 2009.

Projections of water stress based on an ensemble of socioeconomic growth and climate change scenarios: A case study in Asia

DOE PAGES

Fant, Charles; Schlosser, C. Adam; Gao, Xiang; ...

2016-03-30

The sustainability of future water resources is of paramount importance and is affected by many factors, including population, wealth and climate. Inherent in current methods to estimate these factors in the future is the uncertainty of their prediction. In this study, we integrate a large ensemble of scenarios—internally consistent across economics, emissions, climate, and population—to develop a risk portfolio of water stress over a large portion of Asia that includes China, India, and Mainland Southeast Asia in a future with unconstrained emissions. We isolate the effects of socioeconomic growth from the effects of climate change in order to identify themore » primary drivers of stress on water resources. We find that water needs related to socioeconomic changes, which are currently small, are likely to increase considerably in the future, often overshadowing the effect of climate change on levels of water stress. As a result, there is a high risk of severe water stress in densely populated watersheds by 2050, compared to recent history. There is strong evidence to suggest that, in the absence of autonomous adaptation or societal response, a much larger portion of the region’s population will live in water-stressed regions in the near future. Lastly, tools and studies such as these can effectively investigate large-scale system sensitivities and can be useful in engaging and informing decision makers.« less

Water-balance simulations of runoff and reservoir storage for the Upper Helmand watershed and Kajakai Reservoir, central Afghanistan

USGS Publications Warehouse

Vining, Kevin C.; Vecchia, Aldo V.

2007-01-01

A study was performed to provide information on monthly historical and hypothetical future runoff for the Upper Helmand watershed and reservoir storage in Kajakai Reservoir that could be used by Afghanistan authorities to make economic and demographic decisions concerning reservoir design and operation, reservoir sedimentation, and development along the Helmand River. Estimated reservoir volume at the current spillway elevation of 1,033.5 meters decreased by about 365 million cubic meters from 1968 to 2006 because of sedimentation. Water-balance simulations indicated a good fit between modeled and recorded monthly runoff at the two gaging stations in the watershed for water years 1956-79 and indicated an excellent fit between modeled and recorded monthly changes in Kajakai Reservoir storage for water years 1956-79. Future simulations, which included low starting reservoir water levels and a spillway raised to an elevation of 1,045 meters, indicated that the reservoir is likely to fill within 2 years. Although Kajakai Reservoir is likely to fill quickly, multiyear deficits may still occur. If future downstream irrigation demand doubles but future precipitation, temperature, and reservoir sedimentation remain similar to historical conditions, the reservoir would have more than a 50-percent chance of being full during April or May of a typical year. Future simulations with a 10-percent reduction in precipitation indicated that supply deficits would occur more than 1 in 4 years, on average, during August, September, or October. The reservoir would be full during April or May fewer than 1 in 2 years, on average, and multiyear supply deficits could occur. Increased sedimentation had little effect on reservoir levels during April through July, but the frequency of deficits increased substantially during September and October.

The effects of climate change on storm surges around the United Kingdom.

PubMed

Lowe, J A; Gregory, J M

2005-06-15

Coastal flooding is often caused by extreme events, such as storm surges. In this study, improved physical models have been used to simulate the climate system and storm surges, and to predict the effect of increased atmospheric concentrations of greenhouse gases on the surges. In agreement with previous studies, this work indicates that the changes in atmospheric storminess and the higher time-average sea-level predicted for the end of the twenty-first century will lead to changes in the height of water levels measured relative to the present day tide. However, the details of these projections differ somewhat from earlier assessments. Uncertainty in projections of future extreme water levels arise from uncertainty in the amount and timing of future greenhouse gas emissions, uncertainty in the physical models used to simulate the climate system and from the natural variability of the system. The total uncertainty has not yet been reliably quantified and achieving this should be a priority for future research.

Estimating the potential water reuse based on fuzzy reasoning.

PubMed

Almeida, Giovana; Vieira, José; Marques, Alfeu Sá; Kiperstok, Asher; Cardoso, Alberto

2013-10-15

Studies worldwide suggest that the risk of water shortage in regions affected by climate change is growing. Decision support tools can help governments to identify future water supply problems in order to plan mitigation measures. Treated wastewater is considered a suitable alternative water resource and it is used for non-potable applications in many dry regions around the world. This work describes a decision support system (DSS) that was developed to identify current water reuse potential and the variables that determine the reclamation level. The DSS uses fuzzy inference system (FIS) as a tool and multi-criteria decision making is the conceptual approach behind the DSS. It was observed that water reuse level seems to be related to environmental factors such as drought, water exploitation index, water use, population density and the wastewater treatment rate, among others. A dataset was built to analyze these features through water reuse potential with a FIS that considered 155 regions and 183 cities. Despite some inexact fit between the classification and simulation data for agricultural and urban water reuse potential it was found that the FIS was suitable to identify the water reuse trend. Information on the water reuse potential is important because it issues a warning about future water supply needs based on climate change scenarios, which helps to support decision making with a view to tackling water shortage. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impact of climate change on Gironde Estuary

NASA Astrophysics Data System (ADS)

Laborie, Vanessya; Hissel, François; Sergent, Philippe

2014-05-01

Within the THESEUS European project, a simplified mathematical model for storm surge levels in the Bay of Biscay was adjusted on 10 events at Le Verdon using wind and pressure fields from CLM/SGA, so that the water levels at Le Verdon have the same statistic quantiles as observed tide records for the period [1960-2000]. The analysis of future storm surge levels shows a decrease in their quantiles at Le Verdon, whereas there is an increase of the quantiles of total water levels. This increase is smaller than the sea level rise and gets even smaller as one enters farther upstream in the estuary. A numerical model of the Gironde Estuary was then used to evaluate future water levels at 6 locations of the estuary from Le Verdon to Bordeaux and to assess the changes in the quantiles of water levels during the XXIst century using ONERC's pessimistic scenario for sea level rise (60 cm). The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A series of flood maps for different return periods between 2 and 100 years and for four time periods ([1960-1999], [2010-2039], [2040-2069] and [2070-2099]) have been built for the region of Bordeaux. Quantiles of water levels in the floodplain have also been calculated. The impact of climate change on the evolution of flooded areas in the Gironde Estuary and on quantiles of water levels in the floodplain mainly depends on the sea level rise. Areas which are not currently flooded for low return periods will be inundated in 2100. The influence of river discharges and dike breaching should also be taken into account for more accurate results.

Vulnerability of Water Resources under Climate and Land Use Change: Evaluation of Present and Future Threats for Austria

NASA Astrophysics Data System (ADS)

Nachtnebel, Hans-Peter; Wesemann, Johannes; Herrnegger, Mathew; Senoner, Tobias; Schulz, Karsten

2015-04-01

Climate and Land Use Change can have severe impacts on natural water resources needed for domestic, agricultural and industrial water use. In order to develop adaptation strategies, it is necessary to assess the present and future vulnerability of the water resources on the basis of water quantity, water quality and adaptive capacity indicators. Therefore a methodological framework was developed within the CC-Ware project and a detailed assessment was performed for Austria. The Water Exploitation Index (WEI) is introduced as a quantitative indicator. It is defined as the ratio between the water demand and the water availability. Water availability is assessed by a high resolution grid-based water balance model, utilizing the meteorological information from bias corrected regional climate models. The demand term can be divided into domestic, agricultural and industrial water demand and is assessed on the water supply association level. The Integrated Groundwater Pollution Load Index (GWPLI) represents an indicator for areas at risk regarding water quality, considering agricultural loads (nitrate pollution loads), potential erosion and potential risks from landfills. Except for the landfills, the information for the current situation is based on the CORINE Landcover data. Future changes were predicted utilizing the PRELUDE land use scenarios. Since vulnerability is also dependent on the adaptive capacity of a system, the Adaptive Capacity Index is introduced. The Adaptive Capacity Index thereby combines the Ecosystem Service Index (ESSI), which represents three water related ecosystem services (Water Provision, Water Quantity Regulation and Water Quality Regulation) and the regional economic capacity expressed by the gross value added. On the basis of these indices, the Overall Vulnerability of the water resources can be determined for the present and the future. For Austria the different indices were elaborated. Maps indicating areas of different levels of vulnerability were developed. A comparison with existing data (River Basin Management Plan and Groundwater Chemistry Regulation) shows a good agreement between the elaborated maps and observations for the present state. The Overall Vulnerability is very low and low for most parts of Austria, especially in the forested alpine region. Bigger cities like Vienna, Graz and Linz show medium vulnerabilities, due to the high water demand and low ecosystem services. Only in the north-eastern and south-eastern part of the country some water supply associations with high and very high overall vulnerability exist. Groundwater recharge is quite small in these regions and the water quality is limited due to intense agriculture and possible threats through landfills. The developed framework allows an evaluation of water quantity and quality vulnerabilities for large scales for the present and the future. Including ecosystem services and gross value added an overall vulnerability can be determined.

Assessing surface water availability considering human water use and projected climate variability

NASA Astrophysics Data System (ADS)

Ashraf, Batool; AghaKouchak, Amir; Mousavi-Baygi, Mohammd; Moftakhari, Hamed; Anjileli, Hassan

2017-04-01

Climate variability along with anthropogenic activities alter the hydrological cycle and local water availability. The overarching goal of this presentation is to demonstrate the compounding interactions between human water use/withdrawals and climate change and variability. We focus on Karkheh River basin and Urmia basin, in western Iran, that have high level of human activity and water use, and suffer from low water productivity. The future of these basins and their growth relies on sustainable water resources and hence, requires a holistic, basin-wide management to cope with water scarcity challenges. In this study, we investigate changes in the hydrology of the basin including human-induced alterations of the system, during the past three decades. Then, we investigate the individual and combined effects of climate variability and human water withdrawals on surface water storage in the 21st century. We use bias-corrected historical simulations and future projections from ensemble mean of eleven General Circulation Models (GCMs) under two climate change scenarios RCP4.5 and RCP8.5. The results show that, hydrology of the studied basins are significantly dominated by human activities over the baseline period (1976 - 2005). Results show that the increased anthropogenic water demand resulting from substantial socio-economic growth in the past three decades have put significant stress on water resources. We evaluate a number of future water demand scenarios and their interactions with future climate projections. Our results show that by the end of the 21st century, the compounding effects of increased irrigation water demand and precipitation variability may lead to severe local water scarcity in these basins. Our study highlights the necessity for understanding and considering the compounding effects of human water use and future climate projections. Such studies would be useful for improving water management and developing adaption plans in water scarce regions.

The Application of Climate Risk Informed Decision Analysis to the Ioland Water Treatment Plant in Lusaka, Zambia

NASA Astrophysics Data System (ADS)

Kucharski, John; Tkach, Mark; Olszewski, Jennifer; Chaudhry, Rabia; Mendoza, Guillermo

2016-04-01

This presentation demonstrates the application of Climate Risk Informed Decision Analysis (CRIDA) at Zambia's principal water treatment facility, The Iolanda Water Treatment Plant. The water treatment plant is prone to unacceptable failures during periods of low hydropower production at the Kafue Gorge Dam Hydroelectric Power Plant. The case study explores approaches of increasing the water treatment plant's ability to deliver acceptable levels of service under the range of current and potential future climate states. The objective of the study is to investigate alternative investments to build system resilience that might have been informed by the CRIDA process, and to evaluate the extra resource requirements by a bilateral donor agency to implement the CRIDA process. The case study begins with an assessment of the water treatment plant's vulnerability to climate change. It does so by following general principals described in "Confronting Climate Uncertainty in Water Resource Planning and Project Design: the Decision Tree Framework". By utilizing relatively simple bootstrapping methods a range of possible future climate states is generated while avoiding the use of more complex and costly downscaling methodologies; that are beyond the budget and technical capacity of many teams. The resulting climate vulnerabilities and uncertainty in the climate states that produce them are analyzed as part of a "Level of Concern" analysis. CRIDA principals are then applied to this Level of Concern analysis in order to arrive at a set of actionable water management decisions. The principal goals of water resource management is to transform variable, uncertain hydrology into dependable services (e.g. water supply, flood risk reduction, ecosystem benefits, hydropower production, etc…). Traditional approaches to climate adaptation require the generation of predicted future climate states but do little guide decision makers how this information should impact decision making. In this context it is not surprising that the increased hydrologic variability and uncertainty produced by many climate risk analyses bedevil water resource decision making. The Climate Risk Informed Decision Analysis (CRIDA) approach builds on work found in "Confronting Climate Uncertainty in Water Resource Planning and Project Design: the Decision Tree Framework" which provide guidance of vulnerability assessments. It guides practitioners through a "Level of Concern" analysis where climate vulnerabilities are analyzed to produce actionable alternatives and decisions.

Sea Extremes: Integrated impact assessment in coastal climate adaptation

NASA Astrophysics Data System (ADS)

Sorensen, Carlo; Knudsen, Per; Broge, Niels; Molgaard, Mads; Andersen, Ole

2016-04-01

We investigate effects of sea level rise and a change in precipitation pattern on coastal flooding hazards. Historic and present in situ and satellite data of water and groundwater levels, precipitation, vertical ground motion, geology, and geotechnical soil properties are combined with flood protection measures, topography, and infrastructure to provide a more complete picture of the water-related impact from climate change at an exposed coastal location. Results show that future sea extremes evaluated from extreme value statistics may, indeed, have a large impact. The integrated effects from future storm surges and other geo- and hydro-parameters need to be considered in order to provide for the best protection and mitigation efforts, however. Based on the results we present and discuss a simple conceptual model setup that can e.g. be used for 'translation' of regional sea level rise evidence and projections to concrete impact measures. This may be used by potentially affected stakeholders -often working in different sectors and across levels of governance, in a common appraisal of the challenges faced ahead. The model may also enter dynamic tools to evaluate local impact as sea level research advances and projections for the future are updated.

Drinking water studies: a review on heavy metal, application of biomarker and health risk assessment (a special focus in Malaysia).

PubMed

Ab Razak, Nurul Hafiza; Praveena, Sarva Mangala; Aris, Ahmad Zaharin; Hashim, Zailina

2015-12-01

Malaysia has abundant sources of drinking water from river and groundwater. However, rapid developments have deteriorated quality of drinking water sources in Malaysia. Heavy metal studies in terms of drinking water, applications of health risk assessment and bio-monitoring in Malaysia were reviewed from 2003 to 2013. Studies on heavy metal in drinking water showed the levels are under the permissible limits as suggested by World Health Organization and Malaysian Ministry of Health. Future studies on the applications of health risk assessment are crucial in order to understand the risk of heavy metal exposure through drinking water to Malaysian population. Among the biomarkers that have been reviewed, toenail is the most useful tool to evaluate body burden of heavy metal. Toenails are easy to collect, store, transport and analysed. This review will give a clear guidance for future studies of Malaysian drinking water. In this way, it will help risk managers to minimize the exposure at optimum level as well as the government to formulate policies in safe guarding the population. Copyright © 2015 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

Ground-water levels in observation wells in Oklahoma, 1956-1960

USGS Publications Warehouse

Hart, D.L.

1963-01-01

The investigation of the ground-water resources of Oklahoma by the U.S. Geological Survey in cooperation with the Oklahoma Water Resources Board includes a continuing program to collect on a systematic basis records of water levels in selected observation wells. These water-level records: (1) provide an index to available ground-water supplies; (2) facilitate the prediction of trends in water levels that will indicate likely changes in storage; (3) aid in the prediction of the base flow of streams; (4) provide information for use in basic research; and (5) provide long-time continuous records of fluctuations of water levels in representative wells, These selected records also serve as a framework to which other types of hydrologic data may be related.Prior to 1956, measurements of water levels in observation wells in Oklahoma were included in water-supply papers published annually by the U.S. Geological Survey (table 1). Beginning with the 1956 calendar year, however, Federal water-level reports will contain only records of a selected network of observation wells, and will be published by the U.S. Geological Survey at 5-year intervals. The first of this series, for the 1956-59 period has recently been published.This report has been prepared primarily to present water-level records of wells not included in the Federal network. However, for the sake of completeness it includes water-level records of Federal wells that either have been or will be published in Water-Supply Papers since 1955. This report, which contains water-level records for the 5-year period (1956-60), is the first of a series presenting water-level records for all permanent observation wells in Oklahoma. It is planned that future water-level reports will be published at 2-year intervals.

Groundwater-Surface water interaction in agricultural watershed that encompasses dense network of High Capacity wells

NASA Astrophysics Data System (ADS)

Talib, A.; Desai, A. R.

2017-12-01

The Central Sands region of Wisconsin is characterized by productive trout streams, lakes, farmland and forest. However, stream channelization, past wetland drainage, and ground water withdrawals have disrupted the hydrology of this Central Sands region. Climatically driven conditions in last decade (2000-2008) alone are unable to account for the severely depressed water levels. Increased interception and evapotranspiration from afforested areas in central sand Wisconsin may also be culprit for reduced water recharge. Hence, there is need to study the cumulative effects of changing precipitation patterns, groundwater withdrawals, and forest evapotranspiration to improve projections of the future of lake levels and water availability in this region. Here, the SWAT-MODFLOW coupled model approach was applied at large spatio-temporal scale. The coupled model fully integrates a watershed model (SWAT) with a groundwater flow model (MODFLOW). Surface water and ground water flows were simulated integratively at daily time step to estimate the groundwater discharge to the stream network in Central Sands that encompasses high capacity wells. The model was calibrated (2010-2013) and validated (2014-2017) based on streamflow, groundwater extraction, and water table elevation. As the long-term trends in some of the primary drivers is presently ambiguous in Central Sands under future climate, as is the case for total precipitation or timing of precipitation, we relied on a sensitivity student to quantitatively access how primary and secondary drivers may influence future net groundwater recharge. We demonstrate how such an approach could then be coupled with decision-making models to evaluate the effectiveness of groundwater withdrawal policies under a changing climate.

Projections of extreme water level events for atolls in the western Tropical Pacific

NASA Astrophysics Data System (ADS)

Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

2014-12-01

Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

Modelling the impact of future socio-economic and climate change scenarios on river microbial water quality.

PubMed

Islam, M M Majedul; Iqbal, Muhammad Shahid; Leemans, Rik; Hofstra, Nynke

2018-03-01

Microbial surface water quality is important, as it is related to health risk when the population is exposed through drinking, recreation or consumption of irrigated vegetables. The microbial surface water quality is expected to change with socio-economic development and climate change. This study explores the combined impacts of future socio-economic and climate change scenarios on microbial water quality using a coupled hydrodynamic and water quality model (MIKE21FM-ECOLab). The model was applied to simulate the baseline (2014-2015) and future (2040s and 2090s) faecal indicator bacteria (FIB: E. coli and enterococci) concentrations in the Betna river in Bangladesh. The scenarios comprise changes in socio-economic variables (e.g. population, urbanization, land use, sanitation and sewage treatment) and climate variables (temperature, precipitation and sea-level rise). Scenarios have been developed building on the most recent Shared Socio-economic Pathways: SSP1 and SSP3 and Representative Concentration Pathways: RCP4.5 and RCP8.5 in a matrix. An uncontrolled future results in a deterioration of the microbial water quality (+75% by the 2090s) due to socio-economic changes, such as higher population growth, and changes in rainfall patterns. However, microbial water quality improves under a sustainable scenario with improved sewage treatment (-98% by the 2090s). Contaminant loads were more influenced by changes in socio-economic factors than by climatic change. To our knowledge, this is the first study that combines climate change and socio-economic development scenarios to simulate the future microbial water quality of a river. This approach can also be used to assess future consequences for health risks. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

On the effects of adaptive reservoir operating rules in hydrological physically-based models

NASA Astrophysics Data System (ADS)

Giudici, Federico; Anghileri, Daniela; Castelletti, Andrea; Burlando, Paolo

2017-04-01

Recent years have seen a significant increase of the human influence on the natural systems both at the global and local scale. Accurately modeling the human component and its interaction with the natural environment is key to characterize the real system dynamics and anticipate future potential changes to the hydrological regimes. Modern distributed, physically-based hydrological models are able to describe hydrological processes with high level of detail and high spatiotemporal resolution. Yet, they lack in sophistication for the behavior component and human decisions are usually described by very simplistic rules, which might underperform in reproducing the catchment dynamics. In the case of water reservoir operators, these simplistic rules usually consist of target-level rule curves, which represent the average historical level trajectory. Whilst these rules can reasonably reproduce the average seasonal water volume shifts due to the reservoirs' operation, they cannot properly represent peculiar conditions, which influence the actual reservoirs' operation, e.g., variations in energy price or water demand, dry or wet meteorological conditions. Moreover, target-level rule curves are not suitable to explore the water system response to climate and socio economic changing contexts, because they assume a business-as-usual operation. In this work, we quantitatively assess how the inclusion of adaptive reservoirs' operating rules into physically-based hydrological models contribute to the proper representation of the hydrological regime at the catchment scale. In particular, we contrast target-level rule curves and detailed optimization-based behavioral models. We, first, perform the comparison on past observational records, showing that target-level rule curves underperform in representing the hydrological regime over multiple time scales (e.g., weekly, seasonal, inter-annual). Then, we compare how future hydrological changes are affected by the two modeling approaches by considering different future scenarios comprising climate change projections of precipitation and temperature and projections of electricity prices. We perform this comparative assessment on the real-world water system of Lake Como catchment in the Italian Alps, which is characterized by the massive presence of artificial hydropower reservoirs heavily altering the natural hydrological regime. The results show how different behavioral model approaches affect the system representation in terms of hydropower performance, reservoirs dynamics and hydrological regime under different future scenarios.

An urgent need to reassess the safe levels of copper in the drinking water: lessons from studies on healthy animals harboring no genetic deficits.

PubMed

Pal, Amit; Jayamani, Jayagandan; Prasad, Rajendra

2014-09-01

Recent seminal studies have established neurodegeneration, cognitive waning and/or β-amyloid deposition due to chronic copper intoxication via drinking water in healthy animals; henceforth, fuelling the debate all again over the safe levels of copper in the drinking water. This review encompasses the contemporary imperative animal studies in which the effect of chronic copper toxicity (especially via drinking water) was evaluated on the central nervous system and memory of uncompromised animals along with discussing the future perspectives. Copyright © 2014 Elsevier Inc. All rights reserved.

Predicting location-specific extreme coastal floods in the future climate by introducing a probabilistic method to calculate maximum elevation of the continuous water mass caused by a combination of water level variations and wind waves

NASA Astrophysics Data System (ADS)

Leijala, Ulpu; Björkqvist, Jan-Victor; Johansson, Milla M.; Pellikka, Havu

2017-04-01

Future coastal management continuously strives for more location-exact and precise methods to investigate possible extreme sea level events and to face flooding hazards in the most appropriate way. Evaluating future flooding risks by understanding the behaviour of the joint effect of sea level variations and wind waves is one of the means to make more comprehensive flooding hazard analysis, and may at first seem like a straightforward task to solve. Nevertheless, challenges and limitations such as availability of time series of the sea level and wave height components, the quality of data, significant locational variability of coastal wave height, as well as assumptions to be made depending on the study location, make the task more complicated. In this study, we present a statistical method for combining location-specific probability distributions of water level variations (including local sea level observations and global mean sea level rise) and wave run-up (based on wave buoy measurements). The goal of our method is to obtain a more accurate way to account for the waves when making flooding hazard analysis on the coast compared to the approach of adding a separate fixed wave action height on top of sea level -based flood risk estimates. As a result of our new method, we gain maximum elevation heights with different return periods of the continuous water mass caused by a combination of both phenomena, "the green water". We also introduce a sensitivity analysis to evaluate the properties and functioning of our method. The sensitivity test is based on using theoretical wave distributions representing different alternatives of wave behaviour in relation to sea level variations. As these wave distributions are merged with the sea level distribution, we get information on how the different wave height conditions and shape of the wave height distribution influence the joint results. Our method presented here can be used as an advanced tool to minimize over- and underestimation of the combined effect of sea level variations and wind waves, and to help coastal infrastructure planning and support smooth and safe operation of coastal cities in a changing climate.

Taking climate change into estimation of long-term flood risks: A case of Devils Lake of North Dakota, USA

NASA Astrophysics Data System (ADS)

Kharel, G.; Kirilenko, A.

2014-12-01

Terminal lakes are heavily impacted by regional changes in climate. Devils Lake (DL) is a terminal lake located in the northeastern North Dakota of the US. Since 1990, following a shift in regional precipitation pattern, DL has encountered a 10 m water level rise, with over 400% increase in surface area and 600% increase in water volume, costing over $1.5 billion in mitigation. Currently, the lake is <1.5 m from spillover level to the nearby Sheyenne River with potential negative consequences for downstream water quality and flooding. Recently, the artificial outlets have been constructed and operated to divert DL water to the Sheyenne River amid legal and political pressure. Outlet construction however did not take into consideration possible changes in local climate. We modeled the DL basin ( 9,800 km2) hydrology using the Soil and Water Assessment Tool (SWAT) and estimated future water levels of DL for different outlet scenarios under three Intergovernmental Panel on Climate Change (IPCC) SRES scenarios (A1B, B1 & A2) for 2020s and 2050s. We evaluated model performance by comparing SWAT simulated daily streamflow outputs against the observed streamflow data recorded at 6 USGS water gauge locations within the basin. Future climate conditions in the region were estimated by combining historical weather data (1981-2010), 15 CMIP3 General Circulation Model projections from the IPCC data center, and stochastic downscaling methodology (LARS-WG). Our results indicate significant likelihood (7.3% ̶ 20.0%) of uncontrolled DL water overspill in the next few decades in the absence of outlets, with some members of GCM integration ensemble carrying over 85.0% and 95.0% overspill probability for 2020s and 2050s respectively. However, full-capacity outlets show radical reduction in overspill probability to partially mitigate the flooding problem by decreasing the average lake level by approximately 1.9 m and 1.5 m in 2020s and 2050s. Moreover, had there been outlet operation from the beginning of the flood episode since 1990s, not only the future overspill risks but also the current flooding extent would have been reduced significantly (Fig. 1).

Water scarcity and economic damage in Europe: regionally relevant simulations from 2000 to 2050

NASA Astrophysics Data System (ADS)

Bernhard, Jeroen; de Roo, Ad; Bisselink, Bernard; Gelati, Emiliano; Karssenberg, Derek; de Jong, Steven

2017-04-01

Water availability is unequally distributed across Europe. Where certain regions experience a surplus of water, other areas have limited water availability which causes economic damage to the water using sectors such as households, industries or agriculture. Future changes in climatic and socio-economic conditions are expected to further increase the competition for available water that is already present in Europe. This means there is an increasing need for models that are able to simulate this multi-sectorial system of water availability and demand and incorporate the socio-economic component required for robust decisions and policy support. We present our modelling study which is focused at providing regionally relevant pan-European water scarcity and economic damage simulations. First we developed regionally relevant pan-European water demand simulations for the household and industry sector from 2000 up to 2050. For the household sector we developed a model to simulate water use based on water price, income and several other relevant variables at NUTS-3 level (over 1200 regions in Europe). Alternatively, we modelled industrial water use based on regionally downscaled water productivity values at the national level for ten sub-sections of the NACE (Nomenclature of Economic Activities) classification for economic activities. Subsequently we used scenario projections of our explanatory variables to make scenario simulations of water demand from 2000 up to 2050 at pan-European scale with unprecedented spatial and sub-sectorial detail. In order to analyze the European water use system we integrated these water demand scenarios into the hydrological rainfall-runoff model called LISFLOOD (Distributed Water Balance and Flood Simulation Model), which incorporates a vegetation module for the simulation of crop yield and irrigation water demand of the agriculture sector. We simulated river discharge and groundwater availability for abstractions of water using sectors across Europe from 2000 up to 2050 at 5km grid level for multiple climate and socio-economic scenarios. This allowed us to identify regions with water scarcity problems from the recent past up to 2050 and quantify the economic damage that can be attributed to the limited water availability. Results showed several regions where substantially more water is extracted from the system than what would be sustainable into the future. Furthermore, we analyzed how changing water prices or relocation of economic activities could reduce future water scarcity problems and decrease the related economical damage. We found that for some regions, relatively small measurers already could have a positive impact on water scarcity problems.

The effects of country-level population policy for enhancing adaptation to climate change

NASA Astrophysics Data System (ADS)

Gunasekara, N. K.; Kazama, S.; Yamazaki, D.; Oki, T.

2013-11-01

The effectiveness of population policy in reducing the combined impacts of population change and climate change on water resources is explored. One no-policy scenario and two scenarios with population policy assumptions are employed in combination with water availability under the SRES scenarios A1b, B1 and A2 for the impact analysis. The population data used are from the World Bank. The river discharges per grid of horizontal resolution 0.5° are obtained from the Total Runoff Integrating Pathways (TRIP) of the University of Tokyo, Japan. Unlike the population scenarios utilized in the SRES emission scenarios and the newest representative concentration pathways, the scenarios employed in this research are based, even after 2050, on country-level rather than regional-level growth assumptions. Our analysis implies that the heterogeneous pattern of population changes across the world is the dominant driver of water stress, irrespective of future greenhouse gas emissions, with highest impacts occurring in the already water-stressed low latitudes. In 2100, Africa, Middle East and parts of Asia are under extreme water stress under all scenarios. The sensitivity analysis reveals that a small reduction in populations over the region could relieve a large number of people from high water stress, while a further increase in population from the assumed levels (SC1) might not increase the number of people under high water stress considerably. Most of the population increase towards 2100 occurs in the already water-stressed lower latitudes. Therefore, population reduction policies are recommended for this region as a method of adaptation to the future water stress conditions. Population reduction policies will facilitate more control over their future development pathways, even if these countries were not able to contribute significantly to greenhouse gas (GHG) emission cuts due to economic constraints. However, for the European region, the population living in water-stressed regions is almost 20 times lower than that in the lower latitudes. For countries with high population momentum, the population policy scenario with fertility-reduction assumptions gained a maximum of 6.1 times the water availability in Niger and 5.3 times that in Uganda compared with the no-policy scenario. Most of these countries are in sub-Saharan Africa. These countries represent 24.5% of the global population in the no-policy scenario, and the scenario with fertility-reduction assumptions reduces it to 8.7% by 2100. This scenario is also effective in reducing the area under extreme water stress in these countries. However, the policy scenario with assumptions of population stabilization at the replacement fertility rate increases the water stress in high-latitude countries. Nevertheless, the impact is low due to the high per capita water availability in the region. This research is expected to widen the understanding of the combined impacts of climate change in the future and of the strategies needed to enhance the space for adaptation.

Sensitivity of power system operations to projected changes in water availability due to climate change: the Western U.S. case study

NASA Astrophysics Data System (ADS)

Voisin, N.; Macknick, J.; Fu, T.; O'Connell, M.; Zhou, T.; Brinkman, G.

2017-12-01

Water resources provide multiple critical services to the electrical grid through hydropower technologies, from generation to regulation of the electric grid (frequency, capacity reserve). Water resources can also represent vulnerabilities to the electric grid, as hydropower and thermo-electric facilities require water for operations. In the Western U.S., hydropower and thermo-electric plants that rely on fresh surface water represent 67% of the generating capacity. Prior studies have looked at the impact of change in water availability under future climate conditions on expected generating capacity in the Western U.S., but have not evaluated operational risks or changes resulting from climate. In this study, we systematically assess the impact of change in water availability and air temperatures on power operations, i.e. we take into account the different grid services that water resources can provide to the electric grid (generation, regulation) in the system-level context of inter-regional coordination through the electric transmission network. We leverage the Coupled Model Intercomparison Project Phase 5 (CMIP5) hydrology simulations under historical and future climate conditions, and force the large scale river routing- water management model MOSART-WM along with 2010-level sectoral water demands. Changes in monthly hydropower potential generation (including generation and reserves), as well as monthly generation capacity of thermo-electric plants are derived for each power plant in the Western U.S. electric grid. We then utilize the PLEXOS electricity production cost model to optimize power system dispatch and cost decisions for the 2010 infrastructure under 100 years of historical and future (2050 horizon) hydroclimate conditions. We use economic metrics as well as operational metrics such as generation portfolio, emissions, and reserve margins to assess the changes in power system operations between historical and future normal and extreme water availability conditions. We provide insight on how this information can be used to support resource adequacy and grid expansion studies over the Western U.S. in the context of inter-annual variability and climate change.

Assessment of the climate change impacts on fecal coliform contamination in a tidal estuarine system.

PubMed

Liu, Wen-Cheng; Chan, Wen-Ting

2015-12-01

Climate change is one of the key factors affecting the future microbiological water quality in rivers and tidal estuaries. A coupled 3D hydrodynamic and fecal coliform transport model was developed and applied to the Danshuei River estuarine system for predicting the influences of climate change on microbiological water quality. The hydrodynamic and fecal coliform model was validated using observational salinity and fecal coliform distributions. According to the analyses of the statistical error, predictions of the salinity and the fecal coliform concentration from the model simulation quantitatively agreed with the observed data. The validated model was then applied to predict the fecal coliform contamination as a result of climate change, including the change of freshwater discharge and the sea level rise. We found that the reduction of freshwater discharge under climate change scenarios resulted in an increase in the fecal coliform concentration. The sea level rise would decrease fecal coliform distributions because both the water level and the water volume increased. A reduction in freshwater discharge has a negative impact on the fecal coliform concentration, whereas a rising sea level has a positive influence on the fecal coliform contamination. An appropriate strategy for the effective microbiological management in tidal estuaries is required to reveal the persistent trends of climate in the future.

The uncertainty of future water supply adequacy in megacities: Effects of population growth and climate change

NASA Astrophysics Data System (ADS)

Alarcon, T.; Garcia, M. E.; Small, D. L.; Portney, K.; Islam, S.

2013-12-01

Providing water to the expanding population of megacities, which have over 10 million people, with a stressed and aging water infrastructure creates unprecedented challenges. These challenges are exacerbated by dwindling supply and competing demands, altered precipitation and runoff patterns in a changing climate, fragmented water utility business models, and changing consumer behavior. While there is an extensive literature on the effects of climate change on water resources, the uncertainty of climate change predictions continues to be high. This hinders the value of these predictions for municipal water supply planning. The ability of water utilities to meet future water needs will largely depend on their capacity to make decisions under uncertainty. Water stressors, like changes in demographics, climate, and socioeconomic patterns, have varying degrees of uncertainty. Identifying which stressors will have a greater impact on water resources, may reduce the level of future uncertainty for planning and managing water utilities. Within this context, we analyze historical and projected changes of population and climate to quantify the relative impacts of these two stressors on water resources. We focus on megacities that rely primarily on surface water resources to evaluate (a) population growth pattern from 1950-2010 and projected population for 2010-2060; (b) climate change impact on projected climate change scenarios for 2010-2060; and (c) water access for 1950-2010; projected needs for 2010-2060.

Climate change impacts on water availability in the Red River Basin and critical areas for future water conservation

NASA Astrophysics Data System (ADS)

Zamani Sabzi, H.; Moreno, H. A.; Neeson, T. M.; Rosendahl, D. H.; Bertrand, D.; Xue, X.; Hong, Y.; Kellog, W.; Mcpherson, R. A.; Hudson, C.; Austin, B. N.

2017-12-01

Previous periods of severe drought followed by exceptional flooding in the Red River Basin (RRB) have significantly affected industry, agriculture, and the environment in the region. Therefore, projecting how climate may change in the future and being prepared for potential impacts on the RRB is crucially important. In this study, we investigated the impacts of climate change on water availability across the RRB. We used three down-scaled global climate models and three potential greenhouse gas emission scenarios to assess precipitation, temperature, streamflow and lake levels throughout the RRB from 1961 to 2099 at a spatial resolution of 1/10°. Unit-area runoff and streamflow were obtained using the Variable Infiltration Capacity (VIC) model applied across the entire basin. We found that most models predict less precipitation in the western side of the basin and more in the eastern side. In terms of temperature, the models predict that average temperature could increase as much as 6°C. Most models project slightly more precipitation and streamflow values in the future, specifically in the eastern side of the basin. Finally, we analyzed the projected meteorological and hydrologic parameters alongside regional water demand for different sectors to identify the areas on the RRB that will need water-environmental conservation actions in the future. These hotspots of future low water availability are locations where regional environmental managers, water policy makers, and the agricultural and industrial sectors must proactively prepare to deal with declining water availability over the coming decades.

The Water Level Fall of Lake Megali Prespa (N Greece): an Indicator of Regional Water Stress Driven by Climate Change and Amplified by Water Extraction?

NASA Astrophysics Data System (ADS)

van der Schriek, Tim; Giannakopoulos, Christos

2014-05-01

The Mediterranean stands out globally due to its sensitivity to (future) climate change, with future projections predicting an increase in excessive drought events and declining rainfall. Regional freshwater ecosystems are particularly threatened: precipitation decreases, while extreme droughts increase and human impacts intensify (e.g. water extraction, drainage, pollution and dam-building). Many Mediterranean lake-wetland systems have shrunk or disappeared over the past two decades. Protecting the remaining systems is extremely important for supporting global biodiversity and for ensuring sustainable water availability. This protection should be based on a clear understanding of lake-wetland hydrological responses to natural and human-induced changes, which is currently lacking in many parts of the Mediterranean. The interconnected Prespa-Ohrid Lake system is a global hotspot of biodiversity and endemism. The unprecedented fall in water level (~8m) of Lake Megali Prespa threatens this system, but causes remain debated. Modelling suggests that the S Balkan will experience rainfall and runoff decreases of ~30% by 2050. However, projections revealing the potential impact of these changes on future lake level are unavailable as lake regime is not understood. A further drop in lake level may have serious consequences. The Prespa Lakes contribute ~25% of the total inflow into Lake Ohrid through underground karst channels; falling lake levels decrease this discharge. Lake Ohrid, in turn, feeds the Drim River. This entire catchment may therefore be affected by falling lake levels; its water resources are of great importance for Greece, Albania, FYROM and Montenegro (e.g. tourism, agriculture, hydro-energy, urban & industrial use). This new work proves that annual water level fluctuations of Lake Megali Prespa are predominantly related to precipitation during the first 7 months (Oct-Apr) of the hydrological year (Oct-Sep). Lake level is very sensitive to regional and Mediterranean wet-dry events during this period. There are robust indications for a link between lake level and the North Atlantic Oscillation, which is known to strongly influence Mediterranean winter precipitation. Hydro-climatic records show a complicated picture, but tentatively support the conclusion that the unprecedented lake level fall is principally related to climate change. The available fluvial discharge record and most existing snowfall records show statistically significant decreases in annual averages. Annual rainfall only shows a statistically significant decrease of the 25th percentile; 7-month rainfall (Oct-Apr) additionally shows a statistically significant but non-robust decrease of the mean. The modest amount of water extraction (annually: ~14*103m3, ~0.004% of total lake volume) exerts a progressive and significant impact on lake level over the longer term, accounting for ~25% of the observed fall. Lake level lowering ends when lake-surface area shrinkage has led to a decrease in lake-surface evaporation that is equivalent to the amount of water extracted. The adjustment of lake level to stable extraction rates requires two to three decades. This work aims to steer adaptation and mitigation strategies by informing on lake response under different climate change and extraction scenarios. Lake protection is a cost effective solution for supporting global biodiversity and for providing sustainable water resources.

Future Water Management in the South Platte River Basin: Impacts of Hydraulic Fracturing, Population, Agriculture, and Climate Change in a Semi-Arid Region.

NASA Astrophysics Data System (ADS)

Walker, E. L.; Hogue, T. S.; Anderson, A. M.; Read, L.

2015-12-01

In semi-arid basins across the world, the gap between water supply and demand is growing due to climate change, population growth, and shifts in agriculture and unconventional energy development. Water conservation efforts among residential and industrial water users, recycling and reuse techniques and innovative regulatory frameworks for water management strive to mitigate this gap, however, the extent of these strategies are often difficult to quantify and not included in modeling water allocations. Decision support systems (DSS) are purposeful for supporting water managers in making informed decisions when competing demands create the need to optimize water allocation between sectors. One region of particular interest is the semi-arid region of the South Platte River basin in northeastern Colorado, where anthropogenic and climatic effects are expected to increase the gap between water supply and demand in the near future. Specifically, water use in the South Platte is impacted by several high-intensity activities, including unconventional energy development, i.e. hydraulic fracturing, and large withdrawals for agriculture; these demands are in addition to a projected population increase of 100% by 2050. The current work describes the development of a DSS for the South Platte River basin, using the Water Evaluation and Planning system software (WEAP) to explore scenarios of how variation in future water use in the energy, agriculture, and municipal sectors will impact water allocation decisions. Detailed data collected on oil and gas water use in the Niobrara shale play will be utilized to predict future sector use. We also employ downscaled climate projections for the region to quantify the potential range of water availability in the basin under each scenario, and observe whether or not, and to what extent, climate may impact management decisions at the basin level.

Separating decadal global water cycle variability from sea level rise.

PubMed

Hamlington, B D; Reager, J T; Lo, M-H; Karnauskas, K B; Leben, R R

2017-04-20

Under a warming climate, amplification of the water cycle and changes in precipitation patterns over land are expected to occur, subsequently impacting the terrestrial water balance. On global scales, such changes in terrestrial water storage (TWS) will be reflected in the water contained in the ocean and can manifest as global sea level variations. Naturally occurring climate-driven TWS variability can temporarily obscure the long-term trend in sea level rise, in addition to modulating the impacts of sea level rise through natural periodic undulation in regional and global sea level. The internal variability of the global water cycle, therefore, confounds both the detection and attribution of sea level rise. Here, we use a suite of observations to quantify and map the contribution of TWS variability to sea level variability on decadal timescales. In particular, we find that decadal sea level variability centered in the Pacific Ocean is closely tied to low frequency variability of TWS in key areas across the globe. The unambiguous identification and clean separation of this component of variability is the missing step in uncovering the anthropogenic trend in sea level and understanding the potential for low-frequency modulation of future TWS impacts including flooding and drought.

Assessment of the impact of climate change on spatiotemporal variability of blue and green water resources under CMIP3 and CMIP5 models in a highly mountainous watershed

NASA Astrophysics Data System (ADS)

Fazeli Farsani, Iman; Farzaneh, M. R.; Besalatpour, A. A.; Salehi, M. H.; Faramarzi, M.

2018-04-01

The variability and uncertainty of water resources associated with climate change are critical issues in arid and semi-arid regions. In this study, we used the soil and water assessment tool (SWAT) to evaluate the impact of climate change on the spatial and temporal variability of water resources in the Bazoft watershed, Iran. The analysis was based on changes of blue water flow, green water flow, and green water storage for a future period (2010-2099) compared to a historical period (1992-2008). The r-factor, p-factor, R 2, and Nash-Sutcliff coefficients for discharge were 1.02, 0.89, 0.80, and 0.80 for the calibration period and 1.03, 0.76, 0.57, and 0.59 for the validation period, respectively. General circulation models (GCMs) under 18 emission scenarios from the IPCC's Fourth (AR4) and Fifth (AR5) Assessment Reports were fed into the SWAT model. At the sub-basin level, blue water tended to decrease, while green water flow tended to increase in the future scenario, and green water storage was predicted to continue its historical trend into the future. At the monthly time scale, the 95% prediction uncertainty bands (95PPUs) of blue and green water flows varied widely in the watershed. A large number (18) of climate change scenarios fell within the estimated uncertainty band of the historical period. The large differences among scenarios indicated high levels of uncertainty in the watershed. Our results reveal that the spatial patterns of water resource components and their uncertainties in the context of climate change are notably different between IPCC AR4 and AR5 in the Bazoft watershed. This study provides a strong basis for water supply-demand analyses, and the general analytical framework can be applied to other study areas with similar challenges.

Nitrate and drinking water from private wells: will there be an epidemic of cancers of the digestive tract, urinary bladder and thyroid?

PubMed

Njeze, G E; Dilibe, U; Ilo, C

2014-01-01

To estimate the nitrate levels in private wells located in different parts of Enugu and discuss the future health implications following chronic ingestion of well water. The map of Enugu was used to divide the city into many 25 units, using grid lines 1 cm apart. Cluster sampling method was used to collect samples. These samples were sent to two laboratories for estimation of nitrate levels. The people drawing water from the different wells were interviewed to determine what they used the water for. The subjects who were interviewed said they ingested the water. The nitrate levels found in these wells (median value of 31 mg/L) were significantly higher than the internationally accepted levels of nitrate in water for ingestion, (P < 0.0001). High nitrate levels drinking water is dangerous to health and can cause methemoglobinemia in children. It may also increase cancer risk in adults because nitrate is endogenously reduced to nitrite and subsequent nitrosation reactions give rise to N-nitroso compounds (NOCs), which are highly carcinogenic and can act systemically.

Kansas ground-water observation-well network, 1985

USGS Publications Warehouse

Dague, B.J.; Stullken, L.E.

1986-01-01

Water level measurements are made in 1,892 selected wells in 73 counties, which currently (1985) comprise the Kansas groundwater observation-well network. These measurements are made on a continuous, monthly, quarterly, or annual basis. Water level measurements have been made in observation wells since 1937 as part of a cooperative program among the Kansas Geological Survey , the Kansas State Board of Agriculture, the city of Wichita, and the U.S. Geological Survey. The objectives of the observation-well cooperative program are: (1) to provide long-term records of water level fluctuations in representative wells, (2) to facilitate the determination of possible water level trends that may indicate future availability of groundwater supplies, (3) to aid in the determination of possible changes in the base flow of streams, and (4) to provide information for use in water-resources research. This report lists for each well in the network the location, the first year of recorded water level measurement, the frequency and number of measurements, the land-surface altitude, hexagon-grid identifiers for wells in the High Plains aquifer, and the principal geologic unit(s) in which the well is completed. (USGS)

Making markets work for clean water.

PubMed

Carpenter, G

2003-01-01

Part of the solution to close the gap to meet the UN Millennium safe water goal lies in the domestic consumer marketplace. Multinational corporations must design products for low income consumers to deliver clean water at a household level. The future of business is linked to improving the lives of developing country consumers and to the improved economic status of those consumers.

Local Institutional Development and Organizational Change for Advancing Sustainable Urban Water Futures

NASA Astrophysics Data System (ADS)

Brown, Rebekah R.

2008-02-01

This paper presents the local institutional and organizational development insights from a five-year ongoing interdisciplinary research project focused on advancing the implementation of sustainable urban water management. While it is broadly acknowledged that the inertia associated with administrative systems is possibly the most significant obstacle to advancing sustainable urban water management, contemporary research still largely prioritizes investigations at the technological level. This research is explicitly concerned with critically informing the design of methodologies for mobilizing and overcoming the administrative inertia of traditional urban water management practice. The results of fourteen in-depth case studies of local government organizations across Metropolitan Sydney primarily reveal that (i) the political institutionalization of environmental concern and (ii) the commitment to local leadership and organizational learning are key corporate attributes for enabling sustainable management. A typology of five organizational development phases has been proposed as both a heuristic and capacity benchmarking tool for urban water strategists, policy makers, and decision makers that are focused on improving the level of local implementation of sustainable urban water management activity. While this investigation has focused on local government, these findings do provide guideposts for assessing the development needs of future capacity building programs across a range of different institutional contexts.

Local institutional development and organizational change for advancing sustainable urban water futures.

PubMed

Brown, Rebekah R

2008-02-01

This paper presents the local institutional and organizational development insights from a five-year ongoing interdisciplinary research project focused on advancing the implementation of sustainable urban water management. While it is broadly acknowledged that the inertia associated with administrative systems is possibly the most significant obstacle to advancing sustainable urban water management, contemporary research still largely prioritizes investigations at the technological level. This research is explicitly concerned with critically informing the design of methodologies for mobilizing and overcoming the administrative inertia of traditional urban water management practice. The results of fourteen in-depth case studies of local government organizations across Metropolitan Sydney primarily reveal that (i) the political institutionalization of environmental concern and (ii) the commitment to local leadership and organizational learning are key corporate attributes for enabling sustainable management. A typology of five organizational development phases has been proposed as both a heuristic and capacity benchmarking tool for urban water strategists, policy makers, and decision makers that are focused on improving the level of local implementation of sustainable urban water management activity. While this investigation has focused on local government, these findings do provide guideposts for assessing the development needs of future capacity building programs across a range of different institutional contexts.

Water level management of lakes connected to regulated rivers: An integrated modeling and analytical methodology

NASA Astrophysics Data System (ADS)

Hu, Tengfei; Mao, Jingqiao; Pan, Shunqi; Dai, Lingquan; Zhang, Peipei; Xu, Diandian; Dai, Huichao

2018-07-01

Reservoir operations significantly alter the hydrological regime of the downstream river and river-connected lake, which has far-reaching impacts on the lake ecosystem. To facilitate the management of lakes connected to regulated rivers, the following information must be provided: (1) the response of lake water levels to reservoir operation schedules in the near future and (2) the importance of different rivers in terms of affecting the water levels in different lake regions of interest. We develop an integrated modeling and analytical methodology for the water level management of such lakes. The data-driven method is used to model the lake level as it has the potential of producing quick and accurate predictions. A new genetic algorithm-based synchronized search is proposed to optimize input variable time lags and data-driven model parameters simultaneously. The methodology also involves the orthogonal design and range analysis for extracting the influence of an individual river from that of all the rivers. The integrated methodology is applied to the second largest freshwater lake in China, the Dongting Lake. The results show that: (1) the antecedent lake levels are of crucial importance for the current lake level prediction; (2) the selected river discharge time lags reflect the spatial heterogeneity of the rivers' impacts on lake level changes; (3) the predicted lake levels are in very good agreement with the observed data (RMSE ≤ 0.091 m; R2 ≥ 0.9986). This study demonstrates the practical potential of the integrated methodology, which can provide both the lake level responses to future dam releases and the relative contributions of different rivers to lake level changes.

Simulation of groundwater withdrawal scenarios for the Redwall-Muav and Coconino Aquifer Systems of northern and central Arizona

USGS Publications Warehouse

Pool, D.R.

2016-09-23

The Northern Arizona Regional Groundwater Flow Model was used to estimate the hydrologic changes, including water-level change and groundwater discharge to streams and springs, that may result from future changes in groundwater withdrawals in and near the Coconino Plateau Water Advisory Council study area, Coconino and Navajo Counties, Arizona. Three future groundwater withdrawal scenarios for tribal and nontribal uses were developed by the Coconino Plateau Water Advisory Council and were simulated for the period representing the years from 2006 through 2105. Scenario 1 assumes no major changes in groundwater use except for increased demand based on population projections. Scenario 2 assumes that a pipeline will provide a source of surface water from Lake Powell to areas near Cameron and Moenkopi that would replace local groundwater withdrawals. Scenario 3 assumes that the pipeline extends to the Flagstaff and Williams areas, and would replace groundwater demands for water in the area.The Coconino Plateau Water Advisory Council withdrawal scenarios primarily influence water levels and groundwater discharge in the Coconino Plateau basin, near the western margin of the Little Colorado River Plateau basin, and the Verde Valley subbasin. Simulated effects of the withdrawal scenarios are superimposed on effects of previous variations in groundwater withdrawals and artificial and incidental recharge. Pre-scenario variations include changes in water-levels in wells; groundwater storage; discharge to streams and springs; and evapotranspiration by plants that use groundwater. Future variations in groundwater discharge and water-levels in wells will continue to occur as a result of both the past and any future changes.Water-level variations resulting from post-2005 stresses, including groundwater withdrawals and incidental and artificial recharge, in the area of the withdrawal scenarios are primarily localized and superimposed on the regional changes caused by variations in stresses that occurred since the beginning of the initial stresses in the early 1900s through 2005. Withdrawal scenario 1 produced a broad region on the Coconino Plateau where water-levels declined 3–5 feet by 2105, and local areas with water-level declines of 100 feet or more where groundwater withdrawals are concentrated, near the City of Flagstaff Woody Mountain and Lake Mary well fields, and the towns of Tusayan, Williams, and Moenkopi. Water-level rises of 100 feet or more were simulated at areas of incidental recharge near wastewater treatment facilities near Flagstaff, Tusayan, Grand Canyon South Rim, Williams, and Munds Park.Simulated water-level change from 2006 through 2105 for scenarios 2 and 3 is mostly different from water-level change simulated for scenario 1 at the local level. For scenarios 2 and 3, water levels near Cameron in 2105 where 1–3 feet higher than simulated for scenario 1. Water levels at Moenkopi are more than 100 feet higher due to the elimination of a proposed withdrawal well that was simulated in scenario 1. Scenario 3 eliminates more groundwater withdrawals in the Flagstaff and Williams areas, simulates 1–3 feet less water-level decline than scenario 1 across much of the Coconino Plateau, and water levels that are as much as 50 feet higher than simulated by scenario 1 near withdrawal wells in the Williams and Flagstaff areas.Scenario 1 simulated the most change in groundwater discharge for the Little Colorado River below Cameron and for Oak Creek above Page Springs where declines in discharge of about 1.3 and 0.9 cubic feet per second (ft3/s), respectively, were simulated. Other simulated changes in discharge through 2105 in scenario 1 are losses of less than 0.4 ft3/s at the Upper Verde River, losses of less than 0.3 ft3/s at Havasu Creek and at Colorado River below Havasu Creek, losses of less than 0.1 ft3/s at Clear Creek, and increases in flow at the south rim springs and Chevelon Creek of less than 0.1 and 0.3 ft3/s, respectively. Simulated changes in discharge for scenarios 2 and 3 are less than for scenario 1 because of lower rates of groundwater withdrawal. Scenario 3 resulted in greater groundwater discharge than scenarios 1 and 2 at all major groundwater discharge features from 2006 through 2105 except for Clear and Chevelon Creeks, where the same groundwater discharge was simulated by each of the three scenarios.Changes in groundwater discharge are expected to occur after 2105 to all major surface features that discharge from the Redwall-Muav and Coconino aquifers because change in aquifer storage was occurring at the end of the simulation in 2105. The accuracy of simulated changes resulting from the Coconino Plateau Water Advisory Council groundwater withdrawal scenarios is dependent on the persistence of several hydrologic assumptions that are inherent in the Northern Arizona Regional Groundwater Flow Model including, but not limited to, the reasonably accurate simulation of (1) transmissivity distributions, (2) distributions of vertical hydraulic properties, (3) distributions of spatial rates of withdrawal and incidental recharge, (4) aquifer extents, and (5) hydrologic barriers and conduits.

Towards risk-based drought management in the Netherlands: making water supply levels transparent to water users

NASA Astrophysics Data System (ADS)

Maat Judith, Ter; Marjolein, Mens; Vuren Saskia, Van; der Vat Marnix, Van

2016-04-01

To prepare the Dutch Delta for future droughts and water scarcity, a nation-wide 4-year project, called Delta Programme, assessed the impact of climate change and socio-economic development, and explored strategies to deal with these impacts. The Programme initiated a joint approach to water supply management with stakeholders and developed a national adaptation plan that is able to adapt to future uncertain conditions. The adaptation plan consists of a set of preferred policy pathways - sequences of possible actions and measures through time - to achieve targets while responding in a flexible manner to uncertain developments over time, allowing room to respond to new opportunities and insights. With regard to fresh water allocation, the Delta Programme stated that supplying water of sufficient quality is a shared responsibility that requires cohesive efforts among users in the main and regional water system. The national and local authorities and water users involved agreed that the water availability and, where relevant, the water quality should be as transparent and predictable as possible under normal, dry and extremely dry conditions. They therefore introduced the concept of "water supply service levels", which should describe water availability and quality that can be delivered with a certain return period, for all regions and all relevant water users in the Netherlands. The service levels form an addition to the present policy and should be decided on by 2021. At present water allocation during periods of (expected) water shortage occurs according to a prearranged ranking system (a water hierarchy scheme based on a list of priorities), if water availability drops below a critical low level. The aim is to have supply levels available that are based on the probability of occurrence and economic impact of water shortage, and that are transparent for all water users in the regional water systems and the main water system. As part of the European project Improving Predictions and Management of Hydrological Extremes (IMPREX), running from 2016-2019, a consortium of the Dutch research institute Deltares and the Dutch water management consultant HKV will design and build a tool to support quantitative risk-informed decision-making for fresh water management for the Netherlands, in particular the decision on water supply service levels. The research will be conducted in collaboration with the Dutch Ministry for Infrastructure and Environment, the Freshwater Supply Programme Office, the Dutch governmental organisation responsible for water management (Rijkswaterstaat), the Foundation for Applied Water Research, (STOWA, knowledge centre of the water boards) and a number of water boards. In the session we will present the conceptual framework for a risk-based approach for water shortage management and share thoughts on how the proposed tool can be applied in the Dutch water management context.

Integrated Energy-Water Planning in the Western and Texas Interconnections (Invited)

NASA Astrophysics Data System (ADS)

Tidwell, V. C.

2013-12-01

While thermoelectric power generation accounts for less than one percent of total water consumption in the western U.S, steady growth in demand is projected for this sector. Complexities and heterogeneity in water supply, water demand, and institutional controls make water development a challenging proposition throughout the West. A consortium of National Laboratories, the University of Texas and the Electric Power Research Institute are working with the Western Governors' Association and Western States Water Council to assist the Western Electricity Coordinating Council and the Electric Reliability Council of Texas to integrate water related issues into long-term transmission planning. Specifically, water withdrawal and consumption have been estimated for each western power plant and their susceptibility to climate impacts assessed. To assist with transmission planning, water availability and cost data have been mapped at the 8-digit Hydrologic Unit Code level for the conterminous western U.S. (1208 watersheds). Five water sources were individually considered, including unappropriated surface water, unappropriated groundwater, appropriated water, municipal wastewater and brackish groundwater. Also mapped is projected growth in consumptive water demand to 2030. The relative costs (capital and O&M) to secure, convey, and treat the water as necessary have also been estimated for each source of water. These data configured into watershed level supply curves were subsequently used to constrain West-wide transmission planning. Results across a range of alternative energy futures indicate the impact of water availability and cost on the makeup and siting of future power generation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. Water budgets at a 8-digit HUC level constructed by aggregating available water (all five sources) and subtracting projected change in demand for 2010-2030.

Analyzing Uncertainty and Risk in the Management of Water Resources in the State Of Texas

NASA Astrophysics Data System (ADS)

Singh, A.; Hauffpauir, R.; Mishra, S.; Lavenue, M.

2010-12-01

The State of Texas updates its state water plan every five years to determine the water demand required to meet its growing population. The plan compiles forecasts of water deficits from state-wide regional water planning groups as well as the water supply strategies to address these deficits. To date, the plan has adopted a deterministic framework, where reference values (e.g., best estimates, worst-case scenario) are used for key factors such as population growth, demand for water, severity of drought, water availability, etc. These key factors can, however, be affected by multiple sources of uncertainties such as - the impact of climate on surface water and groundwater availability, uncertainty in population projections, changes in sectoral composition of the economy, variability in water usage, feasibility of the permitting process, cost of implementation, etc. The objective of this study was to develop a generalized and scalable methodology for addressing uncertainty and risk in water resources management both at the regional and the local water planning level. The study proposes a framework defining the elements of an end-to-end system model that captures the key components of demand, supply and planning modules along with their associated uncertainties. The framework preserves the fundamental elements of the well-established planning process in the State of Texas, promoting an incremental and stakeholder-driven approach to adding different levels of uncertainty (and risk) into the decision-making environment. The uncertainty in the water planning process is broken down into two primary categories: demand uncertainty and supply uncertainty. Uncertainty in Demand is related to the uncertainty in population projections and the per-capita usage rates. Uncertainty in Supply, in turn, is dominated by the uncertainty in future climate conditions. Climate is represented in terms of time series of precipitation, temperature and/or surface evaporation flux for some future time period of interest, which can be obtained as outputs of global climate models (GCMs). These are then linked with hydrologic and water-availability models (WAMs) to estimate water availability for the worst drought conditions under each future climate scenario. Combining the demand scenarios with the water availability scenarios yields multiple scenarios for water shortage (or surplus). Given multiple shortage/surplus scenarios, various water management strategies can be assessed to evaluate the reliability of meeting projected deficits. These reliabilities are then used within a multi-criteria decision-framework to assess trade-offs between various water management objectives, thus helping to make more robust decisions while planning for the water needs of the future.

A water balance model to estimate flow through the Old and Middle River corridor

USGS Publications Warehouse

Andrews, Stephen W.; Gross, Edward S.; Hutton, Paul H.

2016-01-01

We applied a water balance model to predict tidally averaged (subtidal) flows through the Old River and Middle River corridor in the Sacramento–San Joaquin Delta. We reviewed the dynamics that govern subtidal flows and water levels and adopted a simplified representation. In this water balance approach, we estimated ungaged flows as linear functions of known (or specified) flows. We assumed that subtidal storage within the control volume varies because of fortnightly variation in subtidal water level, Delta inflow, and barometric pressure. The water balance model effectively predicts subtidal flows and approaches the accuracy of a 1–D Delta hydrodynamic model. We explore the potential to improve the approach by representing more complex dynamics and identify possible future improvements.

Simulated water sources and effects of pumping on surface and ground water, Sagamore and Monomoy flow lenses, Cape Cod, Massachusetts

USGS Publications Warehouse

Walter, Donald A.; Whealan, Ann T.

2005-01-01

The sandy sediments underlying Cape Cod, Massachusetts, compose an important aquifer that is the sole source of water for a region undergoing rapid development. Population increases and urbanization on Cape Cod lead to two primary environmental effects that relate directly to water supply: (1) adverse effects of land use on the quality of water in the aquifer and (2) increases in pumping that can adversely affect environmentally sensitive surface waters, such as ponds and streams. These considerations are particularly important on the Sagamore and Monomoy flow lenses, which underlie the largest and most populous areas on Cape Cod. Numerical models of the two flow lenses were developed to simulate ground-water-flow conditions in the aquifer and to (1) delineate areas at the water table contributing water to wells and (2) estimate the effects of pumping and natural changes in recharge on surface waters. About 350 million gallons per day (Mgal/d) of water recharges the aquifer at the water table in this area; most water (about 65 percent) discharges at the coast and most of the remaining water (about 28 percent) discharges into streams. A total of about 24.9 Mgal/d, or about 7 percent, of water in the aquifer is withdrawn for water supply; most pumped water is returned to the hydrologic system as return flow creating a state of near mass balance in the aquifer. Areas at the water table that contribute water directly to production wells total about 17 square miles; some water (about 10 percent) pumped from the wells flows through ponds prior to reaching the wells. Current (2003) steady-state pumping reduces simulated ground-water levels in some areas by more than 4 feet; projected (2020) pumping may reduce water levels by an additional 3 feet or more in these same areas. Current (2003) and future (2020) pumping reduces total streamflow by about 4 and 9 cubic feet per second (ft3/s), corresponding to about 5 percent and 9 percent, respectively, of total streamflow. Natural recharge varies with time, over both monthly and multiyear time scales. Monthly changes in recharge cause pond levels to vary between 1 and 2 feet in an average year; annual changes in recharge, which can be much larger than monthly variations, can cause pond levels to vary by more than 10 feet in some areas over a period of years. Streamflow, which also changes in response to changes in recharge, varies by a factor of two over an average year and can vary more over multiyear periods. On average, monthly pumping ranges from 15.8 Mgal/d in March to 45.3 Mgal/d in August. Pumping and the distribution of return flow can seasonally affect the hydrologic system by lowering ground-water and pond levels and by depleting streamflows, particularly in the summer months. Maximum drawdowns in March and August exceed 3 feet and 6 feet, respectively, for current (2003) pumping. Simulated drawdowns from projected (2020) pumping, relative to water levels representing 2003 pumping conditions, exceed 2 feet in March and 5 feet in August. Current (2003) and future (2020) pumping can decrease pond levels in some areas by more than 3 feet; drawdown generally is largest during the month of August of an average year. Over multiyear periods, seasonal pumping can lower pond levels in some areas by more than 4 feet; the effects of seasonal pumping are largest during periods of reduced recharge. Monthly streamflow depletion varies in individual streams but can exceed 2 ft3/s in some streams. The combined effects of seasonal pumping and drought can reduce pond levels by more than 10 feet below average levels. Water levels in Mary Dunn Pond, which is in an area of large current and projected pumping, are predicted (2020) to decline during drought conditions by about 10.6 feet: about 6.9 feet from lower recharge, about 2.3 feet from current (2003) pumping, and about 1.4 feet from additional future (2020) pumping. The results indicate that pumping generally does not cause substantial

Are implicit policy assumptions about climate adaptation trying to push drinking water utilities down an impossible path?

NASA Astrophysics Data System (ADS)

Klasic, M. R.; Ekstrom, J.; Bedsworth, L. W.; Baker, Z.

2017-12-01

Extreme events such as wildfires, droughts, and flooding are projected to be more frequent and intense under a changing climate, increasing challenges to water quality management. To protect and improve public health, drinking water utility managers need to understand and plan for climate change and extreme events. This three year study began with the assumption that improved climate projections were key to advancing climate adaptation at the local level. Through a survey (N = 259) and interviews (N = 61) with California drinking water utility managers during the peak of the state's recent drought, we found that scientific information was not a key barrier hindering adaptation. Instead, we found that managers fell into three distinct mental models based on their interaction with, perceptions, and attitudes, towards scientific information and the future of water in their system. One of the mental models, "modeled futures", is a concept most in line with how climate change scientists talk about the use of information. Drinking water utilities falling into the "modeled future" category tend to be larger systems that have adequate capacity to both receive and use scientific information. Medium and smaller utilities in California, that more often serve rural low income communities, tend to fall into the other two mental models, "whose future" and "no future". We show evidence that there is an implicit presumption that all drinking water utility managers should strive to align with "modeled future" mental models. This presentation questions this assumption as it leaves behind many utilities that need to adapt to climate change (several thousand in California alone), but may not have the technical, financial, managerial, or other capacity to do so. It is clear that no single solution or pathway to drought resilience exists for water utilities, but we argue that a more explicit understanding and definition of what it means to be a resilient drinking water utility is necessary. By highlighting, then questioning, the assumption that all utility managers should strive to have "modeled future" mentalities, this presentation seeks to foster an open dialogue around which pathway or pathways are most feasible for supporting drinking water utility managers planning for climate change.

Uncertainty considerations in calibration and validation of hydrologic and water quality models

USDA-ARS?s Scientific Manuscript database

Hydrologic and water quality models (HWQMs) are increasingly used to support decisions on the state of various environmental issues and policy directions on present and future scenarios, at scales varying from watershed to continental levels. Uncertainty associated with such models may impact the ca...

LEAD AND COPPER RESEARCH UPDATE: RECENT AND FUTURE AREAS OF WORK

EPA Science Inventory

Although the Lead and Copper Rule has been in place for over 10 years, many drinking water systems still have difficulty in meeting the lead and copper action levels. Some water quality conditions remain either difficult to treat or changes brought about by treatment changes dir...

Past and future drivers of increased erosion risk in the northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Wahl, T.; Plant, N. G.

2014-12-01

We use hourly observations of water levels from two tide gauges and wave data from three buoys to assess their relative contribution to past and potential future changes in the erosion risk for Dauphin Island, a barrier island located off the coastline of Alabama. Topographic information (i.e. beach slopes and dune toe and crest heights) is obtained from the most recent lidar survey conducted in the area in July 2013. Water levels and wave parameters (i.e. significant wave height and peak period) from the two tide gauges and three wave buoys are merged into single records spanning the period from 1981 to 2013. The Stockdon et al. (2006) run-up model is used to estimate the 2% exceedance values of wave run-up maxima, which are then combined with the observed water levels at the representative tide gauge site to obtain total water levels (TWLs). With this information we assess the relative contribution of geocentric sea level rise, vertical land-movement, and long-term changes in the wave parameters to the observed increase in erosion risk. The latter is approximated using the concept of impact hours per year (IHPY; Ruggiero 2013) at dune toe and dune crest elevation thresholds derived from the lidar data. Wahl et al. (2014) recently discovered a significant increase in the amplitude of the seasonal sea level cycle in the Gulf of Mexico. Here, we explore the potential of these changes, and similar developments in the seasonal cycle of the wave data and corresponding IHPY, to affect coastal erosion. Such intra-annual signals with longer-term variations have not been included in most earlier studies in favour of analysing the effects of annually averaged long-term trends. Finally, scenarios of potential future changes of all relevant parameters are used to explore their relative contribution to further increase in the coastal erosion risk over the next few decades.

Coastal Hazards and Integration of Impacts in Local Adaptation Planning

NASA Astrophysics Data System (ADS)

Knudsen, P.; Sorensen, C.; Molgaard, M. R.; Broge, N. H.; Andersen, O. B.

2016-12-01

Data on sea and groundwater levels, precipitation, land subsidence, geology, and geotechnical soil properties are combined with information on flood and erosion protection measures to analyze water-related impacts from climate change at an exposed coastal location. Future sea extremes will have a large impact but several coupled effects in the hydrological system need to be considered as well to provide for optimal protection and mitigation efforts. For instance, the investment and maintenance costs of securing functional water and wastewater pipes are significantly reduced by incorporating knowledge about climate change. The translation of regional sea level rise evidence and projections to concrete impact measures should take into account the potentially affected stakeholders who must collaborate on common and shared adaptation solutions. Here, knowledge integration across levels of governance and between research, private and public institutions, and the local communities provides: understanding of the immediate and potential future challenges; appreciation of different stakeholder motives, business agendas, legislative constraints etc., and a common focus on how to cost-efficiently adapt to and manage impacts of climate change. By construction of a common working platform that is updated with additional data and knowledge, e.g. from future regional models or extreme events, advances in sea level research can more readily be translated into concrete and local impact measures in a way that handles uncertainties in the future climate and urban development as well as suiting the varying stakeholder needs.

Predicting Effects of Water Regime Changes on Waterbirds: Insights from Staging Swans

PubMed Central

Nolet, Bart A.; Gyimesi, Abel; van Krimpen, Roderick R. D.; de Boer, Willem F.; Stillman, Richard A.

2016-01-01

Predicting the environmental impact of a proposed development is notoriously difficult, especially when future conditions fall outside the current range of conditions. Individual-based approaches have been developed and applied to predict the impact of environmental changes on wintering and staging coastal bird populations. How many birds make use of staging sites is mostly determined by food availability and accessibility, which in the case of many waterbirds in turn is affected by water level. Many water systems are regulated and water levels are maintained at target levels, set by management authorities. We used an individual-based modelling framework (MORPH) to analyse how different target water levels affect the number of migratory Bewick’s swans Cygnus columbianus bewickii staging at a shallow freshwater lake (Lauwersmeer, the Netherlands) in autumn. As an emerging property of the model, we found strong non-linear responses of swan usage to changes in water level, with a sudden drop in peak numbers as well as bird-days with a 0.20 m rise above the current target water level. Such strong non-linear responses are probably common and should be taken into account in environmental impact assessments. PMID:26862895

Predicting Effects of Water Regime Changes on Waterbirds: Insights from Staging Swans.

PubMed

Nolet, Bart A; Gyimesi, Abel; van Krimpen, Roderick R D; de Boer, Willem F; Stillman, Richard A

2016-01-01

Predicting the environmental impact of a proposed development is notoriously difficult, especially when future conditions fall outside the current range of conditions. Individual-based approaches have been developed and applied to predict the impact of environmental changes on wintering and staging coastal bird populations. How many birds make use of staging sites is mostly determined by food availability and accessibility, which in the case of many waterbirds in turn is affected by water level. Many water systems are regulated and water levels are maintained at target levels, set by management authorities. We used an individual-based modelling framework (MORPH) to analyse how different target water levels affect the number of migratory Bewick's swans Cygnus columbianus bewickii staging at a shallow freshwater lake (Lauwersmeer, the Netherlands) in autumn. As an emerging property of the model, we found strong non-linear responses of swan usage to changes in water level, with a sudden drop in peak numbers as well as bird-days with a 0.20 m rise above the current target water level. Such strong non-linear responses are probably common and should be taken into account in environmental impact assessments.

Effects of sea-level rise on salt water intrusion near a coastal well field in southeastern Florida

USGS Publications Warehouse

Langevin, Christian D.; Zygnerski, Michael

2013-01-01

A variable-density groundwater flow and dispersive solute transport model was developed for the shallow coastal aquifer system near a municipal supply well field in southeastern Florida. The model was calibrated for a 105-year period (1900 to 2005). An analysis with the model suggests that well-field withdrawals were the dominant cause of salt water intrusion near the well field, and that historical sea-level rise, which is similar to lower-bound projections of future sea-level rise, exacerbated the extent of salt water intrusion. Average 2005 hydrologic conditions were used for 100-year sensitivity simulations aimed at quantifying the effect of projected rises in sea level on fresh coastal groundwater resources near the well field. Use of average 2005 hydrologic conditions and a constant sea level result in total dissolved solids (TDS) concentration of the well field exceeding drinking water standards after 70 years. When sea-level rise is included in the simulations, drinking water standards are exceeded 10 to 21 years earlier, depending on the specified rate of sea-level rise.

Rising water levels and the future of southeastern Louisiana swamp forests

USGS Publications Warehouse

Conner, W.H.; Brody, M.

1989-01-01

An important factor contributing to the deterioration of wetland forests in Louisiana is increasing water levels resulting from eustatic sea-level rise and subsidence. Analyses of long-term water level records from the Barataria and Verret watersheds in southeastern Louisiana indicate an apparent sea level rise of about 1-m per century, mainly the result of subsidence. Permanent study plots were established in cypress-tupelo stands in these two watersheds. The tree, water level, and subsidence data collected in these plots were entered into the U.S. Fish and Wildlife Servicea??s FORFLO bottomland hardwood succession model to determine the long-term effects of rising water levels on forest structure. Analyses were made of 50a??100 years for a cypress-tupelo swamp site in each basin and a bottomland hardwood ridge in the Verret watershed. As flooding increased, less flood tolerant species were replaced by cypress-tupelo within 50 years. As flooding continued, the sites start to become nonforested. From the test analyses, the FORFLO model seems to be an excellent tool for predicting long-term changes in the swamp habitat of south Louisiana.

Research on critical groundwater level under the threshold value of land subsidence in the typical region of Beijing

NASA Astrophysics Data System (ADS)

Jiang, Y.; Liu, J.-R.; Luo, Y.; Yang, Y.; Tian, F.; Lei, K.-C.

2015-11-01

Groundwater in Beijing has been excessively exploited in a long time, causing the groundwater level continued to declining and land subsidence areas expanding, which restrained the economic and social sustainable development. Long years of study show good time-space corresponding relationship between groundwater level and land subsidence. To providing scientific basis for the following land subsidence prevention and treatment, quantitative research between groundwater level and settlement is necessary. Multi-linear regression models are set up by long series factual monitoring data about layered water table and settlement in the Tianzhu monitoring station. The results show that: layered settlement is closely related to water table, water level variation and amplitude, especially the water table. Finally, according to the threshold value in the land subsidence prevention and control plan of China (45, 30, 25 mm), the minimum allowable layered water level in this region while settlement achieving the threshold value is calculated between -18.448 and -10.082 m. The results provide a reasonable and operable control target of groundwater level for rational adjustment of groundwater exploited horizon in the future.

Future extreme water levels and floodplains in Gironde Estuary considering climate change

NASA Astrophysics Data System (ADS)

Laborie, V.; Hissel, F.; Sergent, P.

2012-04-01

Within THESEUS European project, an overflowing model of Gironde Estuary has been used to evaluate future surge levels at Le Verdon and future water levels at 6 specific sites of the estuary : le Verdon, Richard, Laména, Pauillac, Le Marquis and Bordeaux. It was then used to study the evolution of floodplains' location and areas towards 2100 in the entire Estuary. In this study, no breaching and no modification in the elevation of the dike was considered. The model was fed by several data sources : wind fields at Royan and Mérignac interpolated from the grid of the European Climatolologic Model CLM/SGA, a tide signal at Le Verdon, the discharges of Garonne (at La Réole), the Dordogne (at Pessac) and Isle (at Libourne). A simplified mathematical model of surge levels has been adjusted at Le Verdon with 10 surge storms and by using wind and pressure fields given by CLM/SGA. This adjustment was led so that the statistical analysis of the global signal at Le Verdon gives the same quantiles as the same analysis driven on maregraphic observations for the period [1960 ; 2000]. The assumption used for sea level rise was the pessimistic one of the French national institute for climate change: 60 cm in 2100. The model was then used to study the evolution of extreme water levels towards 2100. The analysis of surge levels at Le Verdon shows a decrease in quantiles which is coherent with the analysis of climatologic fields. The analysis of water levels shows that the increase in mean water levels quantiles represents only a part of sea level rise in Gironde Estuary. Moreover this effect seems to decrease from the maritime limit of the model towards upstream. Concerning floodplains, those corresponding to return periods from 2 to 100 years for present conditions and 3 slices [2010; 2039], [2040; 2069] and [2070; 2099] have been mapped for 3 areas in Gironde Estuary : around Le Verdon, at the confluence between Garonne and Dordogne, and near Bordeaux. Concerning the evolution of floodplains in Gironde Estuary, taking into account IPCC scenario A1B, under the same assumptions, it appears that the impact of the climate change on the quantiles of water levels in floodplains depends on the sea level rise over the period considered ([2010; 2039], [2040; 2069], [2070; 2099]) and that areas which are not flooded today for weak return periods become submerged towards 2100. The neighborhood of Le Verdon undergoes a negative impact only in the medium and long term. For the period [2010; 2039], a small reduction of floodplains can be observed in quantiles of water levels for all return periods. Under those assumptions, in the area of Bordeaux, significant effects would be felt along the road RN230 towards 2100. The effects of the discharges and dike breaching will have to be studied in order to precise these results.

Evaluation of the effects of sea-level change and coastal canal management on saltwater intrusion in the Biscayne aquifer of south Florida, USA

NASA Astrophysics Data System (ADS)

Hughes, J. D.; Sifuentes, D. F.; White, J.

2015-12-01

Sea-level increases are expected to have an effect on the position of the freshwater-saltwater interface in the Biscayne aquifer in south Florida as a result of the low topographic relief of the area and high rates of groundwater withdrawal from the aquifer. To study the effects that future sea-level increases will have on saltwater intrusion in the Biscayne aquifer in Broward County, Florida, a three-dimensional, variable-density, groundwater-flow and transport model was developed. The model was calibrated to observed groundwater heads and chloride concentrations for a 62-year period that includes historic increases in sea level, development of a surface-water management system to control flooding, and increases in groundwater withdrawals as the area transitioned from agricultural to urban land uses. Sensitivity analyses indicate that downward leakage of saltwater from coastal canals and creeks was the primary source of saltwater to the Biscayne aquifer during the last 62-years in areas where the surface-water system is not actively managed and is tidally influenced. In areas removed from the coastal canals and creeks or under active surface-water management, historic groundwater withdrawals were the primary cause of saltwater intrusion into the aquifer. Simulation of future conditions suggests that possible increases in sea level will result in additional saltwater intrusion. Model scenarios suggest that additional saltwater intrusion will be greatest in areas where coastal canals and creeks were historically the primary source of seawater. Future saltwater intrusion in those areas, however, may be reduced by relocation of salinity-control structures.

A systematic review of waterborne disease burden methodologies from developed countries.

PubMed

Murphy, H M; Pintar, K D M; McBean, E A; Thomas, M K

2014-12-01

The true incidence of endemic acute gastrointestinal illness (AGI) attributable to drinking water in Canada is unknown. Using a systematic review framework, the literature was evaluated to identify methods used to attribute AGI to drinking water. Several strategies have been suggested or applied to quantify AGI attributable to drinking water at a national level. These vary from simple point estimates, to quantitative microbial risk assessment, to Monte Carlo simulations, which rely on assumptions and epidemiological data from the literature. Using two methods proposed by researchers in the USA, this paper compares the current approaches and key assumptions. Knowledge gaps are identified to inform future waterborne disease attribution estimates. To improve future estimates, there is a need for robust epidemiological studies that quantify the health risks associated with small, private water systems, groundwater systems and the influence of distribution system intrusions on risk. Quantification of the occurrence of enteric pathogens in water supplies, particularly for groundwater, is needed. In addition, there are unanswered questions regarding the susceptibility of vulnerable sub-populations to these pathogens and the influence of extreme weather events (precipitation) on AGI-related health risks. National centralized data to quantify the proportions of the population served by different water sources, by treatment level, source water quality, and the condition of the distribution system infrastructure, are needed.

Assessing hydrological effects of human interventions on coastal systems: numerical applications to the Venice Lagoon

NASA Astrophysics Data System (ADS)

Ferrarin, C.; Ghezzo, M.; Umgiesser, G.; Tagliapietra, D.; Camatti, E.; Zaggia, L.; Sarretta, A.

2012-12-01

The hydrological consequences of historical, contemporary and future human activities on a coastal system were investigated by means of numerical models. The changes in the morphology of the Lagoon of Venice during the last century result from the sedimentological response to the combined effects of human interventions on the environment and global changes. This study focuses on changes from 1927 to 2012 and includes the changes planned for the protection of the city of Venice from storm surges and exceptional tides under future sea level rise scenarios. The application of a hydrodynamic model to simulate the circulation of water masses and the transport of a passive tracer enabled the analysis of the morphodynamic effects on the lagoon circulation and the interaction with the sea. The absolute values of the exchange between the lagoon and sea increased from 1927 to 2002 (from 3900 to 4600 m3 s-1), while the daily fraction of lagoon water volume exchanged decreased. At the same time, the water renewal time shortened from 11.9 to 10.8 days. Morphological changes during the last decade induced an increase of the basin-wide water renewal time (from 10.8 to 11.3 days). In the future, Venice Lagoon will evolve to a more restricted environment due to sea level rise and periodical closure of the lagoon from the sea during flooding events. Simulated scenarios of sea level rise showed that under fall-winter conditions the water renewal time will increased considerably especially in the central part of the lagoon. Furthermore, some considerations on the impact of the hydromorphological changes on the ecological dynamics are proposed.

Molecular Modeling of Water Interfaces: From Molecular Spectroscopy to Thermodynamics.

PubMed

Nagata, Yuki; Ohto, Tatsuhiko; Backus, Ellen H G; Bonn, Mischa

2016-04-28

Understanding aqueous interfaces at the molecular level is not only fundamentally important, but also highly relevant for a variety of disciplines. For instance, electrode-water interfaces are relevant for electrochemistry, as are mineral-water interfaces for geochemistry and air-water interfaces for environmental chemistry; water-lipid interfaces constitute the boundaries of the cell membrane, and are thus relevant for biochemistry. One of the major challenges in these fields is to link macroscopic properties such as interfacial reactivity, solubility, and permeability as well as macroscopic thermodynamic and spectroscopic observables to the structure, structural changes, and dynamics of molecules at these interfaces. Simulations, by themselves, or in conjunction with appropriate experiments, can provide such molecular-level insights into aqueous interfaces. In this contribution, we review the current state-of-the-art of three levels of molecular dynamics (MD) simulation: ab initio, force field, and coarse-grained. We discuss the advantages, the potential, and the limitations of each approach for studying aqueous interfaces, by assessing computations of the sum-frequency generation spectra and surface tension. The comparison of experimental and simulation data provides information on the challenges of future MD simulations, such as improving the force field models and the van der Waals corrections in ab initio MD simulations. Once good agreement between experimental observables and simulation can be established, the simulation can be used to provide insights into the processes at a level of detail that is generally inaccessible to experiments. As an example we discuss the mechanism of the evaporation of water. We finish by presenting an outlook outlining four future challenges for molecular dynamics simulations of aqueous interfacial systems.

Projecting Future Water Levels of the Laurentian Great Lakes

NASA Astrophysics Data System (ADS)

Bennington, V.; Notaro, M.; Holman, K.

2013-12-01

The Laurentian Great Lakes are the largest freshwater system on Earth, containing 84% of North America's freshwater. The lakes are a valuable economic and recreational resource, valued at over 62 billion in annual wages and supporting a 7 billion fishery. Shipping, recreation, and coastal property values are significantly impacted by water level variability, with large economic consequences. Great Lakes water levels fluctuate both seasonally and long-term, responding to natural and anthropogenic climate changes. Due to the integrated nature of water levels, a prolonged small change in any one of the net basin supply components: over-lake precipitation, watershed runoff, or evaporation from the lake surface, may result in important trends in water levels. We utilize the Abdus Salam International Centre for Theoretical Physics's Regional Climate Model Version 4.5.6 to dynamically downscale three global global climate models that represent a spread of potential future climate change for the region to determine whether the climate models suggest a robust response of the Laurentian Great Lakes to anthropogenic climate change. The Model for Interdisciplinary Research on Climate Version 5 (MIROC5), the National Centre for Meteorological Research Earth system model (CNRM-CM5), and the Community Climate System Model Version 4 (CCSM4) project different regional temperature increases and precipitation change over the next century and are used as lateral boundary conditions. We simulate the historical (1980-2000) and late-century periods (2080-2100). Upon model evaluation we will present dynamically downscaled projections of net basin supply changes for each of the Laurentian Great Lakes.

Seasonal presence of cetaceans and ambient noise levels in polar waters of the North Atlantic.

PubMed

Klinck, Holger; Nieukirk, Sharon L; Mellinger, David K; Klinck, Karolin; Matsumoto, Haruyoshi; Dziak, Robert P

2012-09-01

In 2009 two calibrated acoustic recorders were deployed in polar waters of the North Atlantic to study the seasonal occurrence of blue, fin, and sperm whales and to assess current ambient noise levels. Sounds from these cetaceans were recorded at both locations in most months of the year. During the summer months, seismic airguns associated with oil and gas exploration were audible for weeks at a time and dominated low frequency noise levels. Noise levels might further increase in the future as the receding sea ice enables extended human use of the area.

Water demands for electricity generation in the U.S.: Modeling different scenarios for the water–energy nexus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Lu; Hejazi, Mohamad I.; Patel, Pralit L.

Water withdrawal for electricity generation in the United States accounts for approximately half the total freshwater withdrawal. With steadily growing electricity demands, a changing climate, and limited water supplies in many water-scarce states, meeting future energy and water demands poses a significant socio-economic challenge. Employing an integrated modeling approach that can capture the energy-water interactions at regional and national scales is essential to improve our understanding of the key drivers that govern those interactions and the role of national policies. In this study, the Global Change Assessment Model (GCAM), a technologically-detailed integrated model of the economy, energy, agriculture and landmore » use, water, and climate systems, was extended to model the electricity and water systems at the state level in the U.S. (GCAM-USA). GCAM-USA was employed to estimate future state-level electricity generation and consumption, and their associated water withdrawals and consumption under a set of six scenarios with extensive details on the generation fuel portfolio, cooling technology mix, and their associated water use intensities. Six scenarios of future water demands of the U.S. electric-sector were explored to investigate the implications of socioeconomics development and growing electricity demands, climate mitigation policy, the transition of cooling systems, electricity trade, and water saving technologies. Our findings include: 1) decreasing water withdrawals and substantially increasing water consumption from both climate mitigation and the conversion from open-loop to closed-loop cooling systems; 2) open trading of electricity benefiting energy scarce yet demand intensive states; 3) within state variability under different driving forces while across state homogeneity under certain driving force ; 4) a clear trade-off between water consumption and withdrawal for the electricity sector in the U.S. The paper discusses this withdrawal-consumption trade-off in the context of current national policies and regulations that favor decreasing withdrawals (increasing consumptive use), and the role of water saving technologies. The highly-resolved nature of this study both geographically and technologically provides a useful platform to address scientific and policy relevant and emerging issues at the heart of the water-energy nexus in the U.S.« less

The Water Footprint as an indicator of environmental sustainability in water use at the river basin level.

PubMed

Pellicer-Martínez, Francisco; Martínez-Paz, José Miguel

2016-11-15

One of the main challenges in water management is to determine how the current water use can condition its availability to future generations and hence its sustainability. This study proposes the use of the Water Footprint (WF) indicator to assess the environmental sustainability in water resources management at the river basin level. The current study presents the methodology developed and applies it to a case study. The WF is a relatively new indicator that measures the total volume of freshwater that is used as a production factor. Its application is ever growing in the evaluation of water use in production processes. The calculation of the WF involves water resources (blue), precipitation stored in the soil (green) and pollution (grey). It provides a comprehensive assessment of the environmental sustainability of water use in a river basin. The methodology is based upon the simulation of the anthropised water cycle, which is conducted by combining a hydrological model and a decision support system. The methodology allows the assessment of the environmental sustainability of water management at different levels, and/or ex-ante analysis of how the decisions made in water planning process affect sustainability. The sustainability study was carried out in the Segura River Basin (SRB) in South-eastern Spain. The SRB is among the most complex basins in Europe, given its special peculiarities: competition for the use, overexploitation of aquifers, pollution, alternative sources, among others. The results indicate that blue water use is not sustainable due to the generalised overexploitation of aquifers. They also reveal that surface water pollution, which is not sustainable, is mainly caused by phosphate concentrations. The assessment of future scenarios reveals that these problems will worsen if no additional measures are implemented, and therefore the water management in the SRB is environmentally unsustainable in both the short- and medium-term. Copyright © 2016 Elsevier B.V. All rights reserved.

Selected water-level records for Oklahoma, 1976-1978

USGS Publications Warehouse

Goemaat, Robert L.; Spiser, Dannie E.

1979-01-01

A systematic program to collect water-level records in Oklahoma began in 1937. The objectives of this program are (1) to provide long-term records of water-level fluctuations in representative wells, (2) to facilitate the prediction of water-level trends and indicate future availability of ground-water supplies, and (3) to provide information for use in basic research.Water-level data in table 1 are from wells that are measured annually, prior to the irrigation season, to achieve the most natural representation of the static water level. Water-level measurements listed in the column under 1976 may have been made during December 1975 or January, February, March, April, or May, 1976. Measurements listed in the column 1977 may have been made during December 1976 or January, February, March, or April 1977. Figure 1 shows the counties and number of wells therein, where data were obtained for this report.Records of water levels in Oklahoma are collected through a cooperative program by the U.S. Geological Survey and the Oklahoma Water Resources Board. The records are tabulated and published by the U.S. Geological Survey on an annual basis.The stratigraphic nomenclature and age determinations used in this report are those accepted by the Oklahoma Geological Survey and do not necessarily agree with those of the U.S. Geological Survey except for the Cheyenne Sandstone which is considered to be Purgatoire Sandstone by the Oklahoma Geological Survey (Robert 0. Fay, Personal Communication, August 9, 1979).

Future irrigation expansion outweigh groundwater recharge gains from climate change in semi-arid India.

PubMed

Sishodia, Rajendra P; Shukla, Sanjay; Wani, Suhas P; Graham, Wendy D; Jones, James W

2018-09-01

Simultaneous effects of future climate and irrigation intensification on surface and groundwater systems are not well understood. Efforts are needed to understand the future groundwater availability and associated surface flows under business-as-usual management to formulate policy changes to improve water sustainability. We combine measurements with integrated modeling (MIKE SHE/MIKE11) to evaluate the effects of future climate (2040-2069), with and without irrigation expansion, on water levels and flows in an agricultural watershed in low-storage crystalline aquifer region of south India. Demand and supply management changes, including improved efficiency of irrigation water as well as energy uses, were evaluated. Increased future rainfall (7-43%, from 5 Global Climate Models) with no further expansion of irrigation wells increased the groundwater recharge (10-55%); however, most of the recharge moved out of watershed as increased baseflow (17-154%) with a small increase in net recharge (+0.2mm/year). When increased rainfall was considered with projected increase in irrigation withdrawals, both hydrologic extremes of well drying and flooding were predicted. A 100-year flow event was predicted to be a 5-year event in the future. If irrigation expansion follows the historical trends, earlier and more frequent well drying, a source of farmers' distress in India, was predicted to worsen in the future despite the recharge gains from increased rainfall. Storage and use of excess flows, improved irrigation efficiency with flood to drip conversion in 25% of irrigated area, and reduced energy subsidy (free electricity for 3.5h compared to 7h/day; $1 billion savings) provided sufficient water savings to support future expansion in irrigated areas while mitigating well drying as well as flooding. Reductions in energy subsidy to fund the implementation of economically desirable (high benefit-cost ratio) demand (drip irrigation) and supply (water capture and storage) management was recommended to achieve a sustainable food-water-energy nexus in semi-arid regions. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of water-quality characteristics and sampling design for streams in North Dakota, 1970–2008

USGS Publications Warehouse

Galloway, Joel M.; Vecchia, Aldo V.; Vining, Kevin C.; Densmore, Brenda K.; Lundgren, Robert F.

2012-01-01

In response to the need to examine the large amount of historic water-quality data comprehensively across North Dakota and evaluate the efficiency of the State-wide sampling programs, a study was done by the U.S. Geological Survey in cooperation with the North Dakota State Water Commission and the North Dakota Department of Health to describe the water-quality data collected for the various programs and determine an efficient State-wide sampling design for monitoring future water-quality conditions. Although data collected for the North Dakota State Water Commission High-Low Sampling Program, the North Dakota Department of Health Ambient Water-Quality Network, and other projects and programs provide valuable information on the quality of water in streams in North Dakota, the objectives vary among the programs, some of the programs overlap spatially and temporally, and the various sampling designs may not be the most efficient or relevant to the objectives of the individual programs as they have changed through time. One objective of a State-wide sampling program was to evaluate ways to describe the spatial variability of water-quality conditions across the State in the most efficient manner. Weighted least-squares regression analysis was used to relate the average absolute difference between paired downstream and upstream concentrations, expressed as a percent of the average downstream concentration, to the average absolute difference in daily flow between the downstream and upstream pairs, expressed as a percent of the average downstream flow. The analysis showed that a reasonable spatial network would consist of including the most downstream sites in large basins first, followed by the next upstream site(s) that roughly bisect the downstream flows at the first sites, followed by the next upstream site(s) that roughly bisect flows for the second sites. Sampling sites to be included in a potential State-wide network were prioritized into 3 design levels: level 1 (highest priority), level 2 (second priority), and level 3 (third priority). Given the spatial distribution and priority designation (levels 1–3) of sites in the potential spatial network, the next consideration was to determine the appropriate temporal sampling frequency to use for monitoring future water-quality conditions. The time-series model used to detect concentration trends for this report also was used to evaluate sampling designs to monitor future water-quality trends. Sampling designs were evaluated with regard to their sensitivity to detect seasonal trends that occurred during three 4-month seasons—March through June, July through October, and November through February. For the 34 level-1 sites, samples would be collected for major ions, trace metals, nutrients, bacteria, and sediment eight times per year, with samples in January, April (2 samples),May, June, July, August, and October. For the 21 level-2 sites, samples would be collected for major ions, trace metals, and nutrients six times per year (January, April, May, June, August, and October), and for the 26 level-3 sites, samples would be collected for these constituents four times per year (April, June, August, and October).

Water Level Prediction of Lake Cascade Mahakam Using Adaptive Neural Network Backpropagation (ANNBP)

NASA Astrophysics Data System (ADS)

Mislan; Gaffar, A. F. O.; Haviluddin; Puspitasari, N.

2018-04-01

A natural hazard information and flood events are indispensable as a form of prevention and improvement. One of the causes is flooding in the areas around the lake. Therefore, forecasting the surface of Lake water level to anticipate flooding is required. The purpose of this paper is implemented computational intelligence method namely Adaptive Neural Network Backpropagation (ANNBP) to forecasting the Lake Cascade Mahakam. Based on experiment, performance of ANNBP indicated that Lake water level prediction have been accurate by using mean square error (MSE) and mean absolute percentage error (MAPE). In other words, computational intelligence method can produce good accuracy. A hybrid and optimization of computational intelligence are focus in the future work.

Assessing Water Level Changes in Lake, Reservoir, Wetland, and River Systems with Remote Sensing Tools and Hydrological Model

NASA Astrophysics Data System (ADS)

Ricko, M.; Birkett, C. M.; Beckley, B. D.

2017-12-01

The NASA/USDA Global Reservoir and Lake Monitor (G-REALM) offers multi-mission satellite radar altimetry derived surface water level products for a subset of large reservoirs, lakes, and wetlands. These products complement the in situ networks by providing stage information at un-gauged locations, and filling existing data gaps. The availability of both satellite-based rainfall (e.g., TRMM, GPCP) and surface water level products offers great opportunities to estimate and monitor additional hydrologic properties of the lake/reservoir systems. A simple water balance model relating the net freshwater flux over a catchment basin to the lake/reservoir level has been previously utilized (Ricko et al., 2011). The applicability of this approach enables the construction of a longer record of surface water level, i.e. improving the climate data record. As instrument technology and data availability evolve, this method can be used to estimate the water level of a greater number of water bodies, and a greater number of much smaller targets. In addition, such information can improve water balance estimation in different lake, reservoir, wetland, and river systems, and be very useful for assessment of improved prediction of surface water availability. Connections to climatic variations on inter-annual to inter-decadal time-scales are explored here, with a focus on a future ability to predict changes in storage volume for water resources or natural hazards concerns.

Hydrologic reconnaissance of the southern Uinta basin, Utah and Colorado

USGS Publications Warehouse

Price, Don; Miller, Louise L.

1975-01-01

This report summarizes the findings of an investigation of the water resources of the southern Uinta Basin conducted by the U.S. Geological Survey in cooperation with the Utah Department of Natural Resources, Division of Water Rights. The purpose of the investigation was to evaluate the water resources of the southern Uinta Basin on a reconnaissance level and to provide information to assist in future planning and development of the water and related land resources.

Assessing hydrological drought risk for the irrigation sector in future climate scenarios: lessons learned from the Apulia case study (Italy)

NASA Astrophysics Data System (ADS)

Critto, Andrea; Torresan, Silvia; Ronco, Paolo; Zennaro, Federica; Santini, Monia; Trabucco, Antonio; Marcomini, Antonio

2016-04-01

Climate change is already affecting the frequency of drought events which may threaten the current stocks of water resources and thus the availability of freshwater for the irrigation. The achievement of a sustainable equilibrium between the availability of water resources and the irrigation demand is essentially related to the planning and implementation of evidence-based adaptation strategies and actions. In this sense, the improvement (of existing) and the development of (new) appropriate risk assessment methods and tools to evaluate the impact of drought events on irrigated crops is fundamental in order to assure that the agricultural yields are appropriate to meet the current and future food and market demand. This study evaluates the risk of hydrological drought on the irrigated agronomic compartment of Apulia, a semi-arid region in Southern Italy. We applied a stepwise Regional Risk Assessment (RRA) procedure, based on the consecutive analysis of hazards, exposure, vulnerability and risks, integrating the qualitative and quantitative available information. Future climate projections for the timeframes 2021-2050 and 2041-2070 were provided by COSMO-CLM under the radiative forcing RCP4.5 and RCP8.5. The run-off feeding the water stocks of the most important irrigation reservoirs in Apulia was then modeled with Arc-SWAT. Hence, the hazard analysis was carried out in order to estimate the degree of fulfillment of actual irrigation demand satisfied by water supply of different reservoirs in future scenarios. Vulnerability of exposed irrigated crops was evaluated depending on three factors accounting for crop yield variation vs water stress, water losses along the irrigation network, diversification of water supply. Resulting risk and vulnerability maps allowed: the identification of Reclamation Consortia at higher risk of not fulfilling their future irrigation demand (e.g. Capitanata Reclamation Consortia in RCP8.5 2041-2070 scenario); the ranking of most affected crops (e.g. fruit trees and vineyards); and finally, the characterization of vulnerability pattern of irrigation systems. Major achievements included the definition of a portfolio of science-driven adaptation strategies to reduce the risk pattern at both agronomic level (preferring crops with low vulnerability score, as olive groves) and at structural level (differentiating the water stocks and supplies and reducing losses and inefficiencies).

User requirements and user acceptance of current and next-generation satellite mission and sensor complement, oriented toward the monitoring of water resources

NASA Technical Reports Server (NTRS)

Castruccio, P. A.; Loats, H. L., Jr.; Fowler, T. R.; Robinson, P.

1975-01-01

Principal water resources users were surveyed to determine the applicability of remotely sensed data to their present and future requirements. Analysis of responses was used to assess the levels of adequacy of LANDSAT 1 and 2 in fulfilling hydrological functions, and to derive systems specifications for future water resources-oriented remote sensing satellite systems. The analysis indicates that water resources applications for all but the very large users require: (1) resolutions on the order of 15 meters, (2) a number of radiometric levels of the same order as currently used in LANDSAT 1 (64), (3) a number of spectral bands not in excess of those used in LANDSAT 1, and (4) a repetition frequency on the order of 2 weeks. The users had little feel for the value of new sensors (thermal IR, passive and active microwaves). What is needed in this area is to achieve specific demonstrations of the utility of these sensors and submit the results to the users to evince their judgement.

Questions and Answers About the Effects of Septic Systems on Water Quality in the La Pine Area, Oregon

USGS Publications Warehouse

Williams, John S.; Morgan, David S.; Hinkle, Stephen R.

2007-01-01

Nitrate levels in the ground-water aquifer underlying the central Oregon city of La Pine and the surrounding area are increasing due to contamination from residential septic systems. This contamination has public health implications because ground water is the sole source of drinking water for area residents. The U.S. Geological Survey, in cooperation with Deschutes County and the Oregon Department of Environmental Quality, studied the movement and chemistry of nitrate in the aquifer and developed computer models that can be used to predict future nitrate levels and to evaluate alternatives for protecting water quality. This fact sheet summarizes the results of that study in the form of questions and answers.

Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study.

PubMed

Manassaram, Deana M; Backer, Lorraine C; Messing, Rita; Fleming, Lora E; Luke, Barbara; Monteilh, Carolyn P

2010-10-14

Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Pregnant women showed a decrease in methemoglobin levels with increasing gestation although <1% had levels above the physiologic normal of 2% methemoglobin, regardless of the source of their drinking water. The multivariable analyses did not show a statistically significant association between methemoglobin levels and the estimated nitrate intake from tap water among pregnant women around 36 weeks gestation (β = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p < 0.0001). Also, a greater proportion of private well users (27%) compared to public system users (13%) were using devices capable of removing nitrate from water (p < 0.0001). Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and should be considered in the assessment of exposure to nitrates in future studies.

Nitrates in drinking water and methemoglobin levels in pregnancy: a longitudinal study

PubMed Central

2010-01-01

Background Private water systems are more likely to have nitrate levels above the maximum contaminant level (MCL). Pregnant women are considered vulnerable to the effects of exposure to high levels of nitrates in drinking water due to their altered physiological states. The level of methemoglobin in the blood is the biomarker often used in research for assessing exposure to nitrates. The objective of this study was to assess methemoglobin levels and examine how various factors affected methemoglobin levels during pregnancy. We also examined whether differences in water use practices existed among pregnant women based on household drinking water source of private vs. public supply. Methods A longitudinal study of 357 pregnant women was conducted. Longitudinal regression models were used to examine changes and predictors of the change in methemoglobin levels over the period of gestation. Results Pregnant women showed a decrease in methemoglobin levels with increasing gestation although <1% had levels above the physiologic normal of 2% methemoglobin, regardless of the source of their drinking water. The multivariable analyses did not show a statistically significant association between methemoglobin levels and the estimated nitrate intake from tap water among pregnant women around 36 weeks gestation (β = 0.046, p = 0.986). Four women had tap water nitrate levels above the MCL of 10 mg/L. At enrollment, a greater proportion of women who reported using water treatment devices were private wells users (66%) compared to public system users (46%) (p < 0.0001). Also, a greater proportion of private well users (27%) compared to public system users (13%) were using devices capable of removing nitrate from water (p < 0.0001). Conclusion Pregnant women potentially exposed to nitrate levels primarily below the MCL for drinking water were unlikely to show methemoglobin levels above the physiologic normal. Water use practices such as the use of treatment devices to remove nitrates varied according to water source and should be considered in the assessment of exposure to nitrates in future studies. PMID:20946657

Water-Balance Model to Simulate Historical Lake Levels for Lake Merced, California

NASA Astrophysics Data System (ADS)

Maley, M. P.; Onsoy, S.; Debroux, J.; Eagon, B.

2009-12-01

Lake Merced is a freshwater lake located in southwestern San Francisco, California. In the late 1980s and early 1990s, an extended, severe drought impacted the area that resulted in significant declines in Lake Merced lake levels that raised concerns about the long-term health of the lake. In response to these concerns, the Lake Merced Water Level Restoration Project was developed to evaluate an engineered solution to increase and maintain Lake Merced lake levels. The Lake Merced Lake-Level Model was developed to support the conceptual engineering design to restore lake levels. It is a spreadsheet-based water-balance model that performs monthly water-balance calculations based on the hydrological conceptual model. The model independently calculates each water-balance component based on available climate and hydrological data. The model objective was to develop a practical, rule-based approach for the water balance and to calibrate the model results to measured lake levels. The advantage of a rule-based approach is that once the rules are defined, they enhance the ability to then adapt the model for use in future-case simulations. The model was calibrated to historical lake levels over a 70-year period from 1939 to 2009. Calibrating the model over this long historical range tested the model over a variety of hydrological conditions including wet, normal and dry precipitation years, flood events, and periods of high and low lake levels. The historical lake level range was over 16 feet. The model calibration of historical to simulated lake levels had a residual mean of 0.02 feet and an absolute residual mean of 0.42 feet. More importantly, the model demonstrated the ability to simulate both long-term and short-term trends with a strong correlation of the magnitude for both annual and seasonal fluctuations in lake levels. The calibration results demonstrate an improved conceptual understanding of the key hydrological factors that control lake levels, reduce uncertainty in the hydrological conceptual model, and increase confidence in the model’s ability to forecast future lake conditions. The Lake Merced Lake-Level Model will help decision-makers with a straightforward, practical analysis of the major contributions to lake-level declines that can be used to support engineering, environmental and other decisions.

Income-based projections of water footprint of food consumption in Uzbekistan

NASA Astrophysics Data System (ADS)

Djanibekov, Nodir; Frohberg, Klaus; Djanibekov, Utkur

2013-11-01

Assessing future water requirements for feeding the growing population of Central Asia can improve understanding of the projected water supply scenarios in the region. Future water requirements will be partially determined by the dietary habits of the populations, and are thus responsive to significant variation of income levels. Using Uzbekistan as an example, this study projects the water footprints of income driven changes on the population's diet in Central Asia. To reveal the influence of large income changes on dietary habits a Normalized Quadratic-Quadratic Expenditure System was calibrated and applied to data from 2009. The national water footprints of food consumption in Uzbekistan were projected until 2034 by applying the parameterized demand system to estimate the respective water footprint values. The results showed that for Uzbekistan the projected increase in the food consumption water footprint would be primarily linked to income growth rather than population growth. Due to the high water footprint of common food products, the composition of the population's diet, and responsiveness to income, economic growth is expected to put greater pressure on water resources in Uzbekistan unless proper measures are undertaken.

Assessing the effects of adaptation measures on optimal water resources allocation under varied water availability conditions

NASA Astrophysics Data System (ADS)

Liu, Dedi; Guo, Shenglian; Shao, Quanxi; Liu, Pan; Xiong, Lihua; Wang, Le; Hong, Xingjun; Xu, Yao; Wang, Zhaoli

2018-01-01

Human activities and climate change have altered the spatial and temporal distribution of water availability which is a principal prerequisite for allocation of different water resources. In order to quantify the impacts of climate change and human activities on water availability and optimal allocation of water resources, hydrological models and optimal water resource allocation models should be integrated. Given that increasing human water demand and varying water availability conditions necessitate adaptation measures, we propose a framework to assess the effects of these measures on optimal allocation of water resources. The proposed model and framework were applied to a case study of the middle and lower reaches of the Hanjiang River Basin in China. Two representative concentration pathway (RCP) scenarios (RCP2.6 and RCP4.5) were employed to project future climate, and the Variable Infiltration Capacity (VIC) hydrological model was used to simulate the variability of flows under historical (1956-2011) and future (2012-2099) conditions. The water availability determined by simulating flow with the VIC hydrological model was used to establish the optimal water resources allocation model. The allocation results were derived under an extremely dry year (with an annual average water flow frequency of 95%), a very dry year (with an annual average water flow frequency of 90%), a dry year (with an annual average water flow frequency of 75%), and a normal year (with an annual average water flow frequency of 50%) during historical and future periods. The results show that the total available water resources in the study area and the inflow of the Danjiangkou Reservoir will increase in the future. However, the uneven distribution of water availability will cause water shortage problems, especially in the boundary areas. The effects of adaptation measures, including water saving, and dynamic control of flood limiting water levels (FLWLs) for reservoir operation, were assessed and implemented to alleviate water shortages. The negative impacts from the South-to-North Water Transfer Project (Middle Route) in the mid-lower reaches of the Hanjiang River Basin can be avoided through the dynamic control of FLWLs in Danjiangkou Reservoir, under the historical and future RCP2.6 and RCP4.5 scenarios. However, the effects of adaptation measures are limited due to their own constraints, such as the characteristics of the reservoirs influencing the FLWLs. The utilization of storm water appears necessary to meet future water demand. Overall, the results indicate that the framework for assessing the effects of adaptation measures on water resources allocation might aid water resources management, not only in the study area but also in other places where water availability conditions vary due to climate change and human activities.

Ground-water protection, low-level waste, and below regulatory concern: What`s the connection?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gruhlke, J.M.; Galpin, F.L.

1991-12-31

The Environmental Protection Agency (EPA) has a responsibility to protect ground water and drinking water under a wide variety of statutes. Each statute establishes different but specific requirements for EPA and applies to diverse environmental contaminants. Radionuclides are but one of the many contaminants subject to this regulatory matrix. Low-level radioactive waste (LLW) and below regulatory concern (BRC) are but two of many activities falling into this regulatory structure. The nation`s ground water serves as a major source of drinking water, supports sensitive ecosystems, and supplies the needs of agriculture and industry. Ground water can prove enormously expensive to cleanmore » up. EPA policy for protecting ground water has evolved considerably over the last ten years. The overall goal is to prevent adverse effects to human health, both now and in the future, and to protect the integrity of the nation`s ground-water resources. The Agency uses the Maximum Contaminant Levels (MCLs) under the Safe Drinking Water Act as reference points for protection in both prevention and remediation activities. What`s the connection? Both low-level waste management and disposal activities and the implementation of below regulatory concern related to low-level waste disposal have the potential for contaminating ground water. EPA is proposing to use the MCLs as reference points for low-level waste disposal and BRC disposal in order to define limits to the environmental contamination of ground water that is, or may be, used for drinking water.« less

The Blackwater NWR inundation model. Rising sea level on a low-lying coast: land use planning for wetlands

USGS Publications Warehouse

Larsen, Curt; Clark, Inga; Guntenspergen, Glenn; Cahoon, Don; Caruso, Vincent; Hupp, Cliff; Yanosky, Tom

2004-01-01

The Blackwater National Wildlife Refuge (BNWR), on the Eastern Shore of Chesapeake Bay (figure 1), occupies an area less than 1 meter above sea level. The Refuge has been featured prominently in studies of the impact of sea level rise on coastal wetlands. Most notably, the refuge has been sited by the Intergovernmental Panel on Climate Change (IPCC) as a key example of 'wetland loss' attributable to rising sea level due to global temperature increase. Comparative studies of aerial photos taken since 1938 show an expanding area of open water in the central area of the refuge. The expanding area of open water can be shown to parallel the record of sea level rise over the past 60 years. The U.S. Fish and Wildlife Service (FWS) manages the refuge to support migratory waterfowl and to preserve endangered upland species. High marsh vegetation is critical to FWS waterfowl management strategies. A broad area once occupied by high marsh has decreased with rising sea level. The FWS needs a planning tool to help predict current and future areas of high marsh available for waterfowl. 'Wetland loss' is a relative term. It is dependant on the boundaries chosen for measurement. Wetland vegetation, zoned by elevation and salinity (figure 3), respond to rising sea level. Wetlands migrate inland and upslope and may vary in areas depending on the adjacent land slopes. Refuge managers need a geospatial tool that allows them to predict future areas that will be converted to high and intertidal marsh. Shifts in location and area of coverage must be anticipated. Viability of a current marsh area is also important. When will sea level rise make short-term management strategies to maintain an area impractical? The USGS has developed an inundation model for the BNWR centered on the refuge and surrounding areas. Such models are simple in concept, but they require a detailed topographic map upon which to superimpose future sea level positions. The new system of LIDAR mapping of land and shallow water surfaces has solved this problem. Our team has developed a detailed LIDAR map of the BNWR area at a 30 centimeter (ca. 1 ft) contour interval (figure 2). The new map allows us to identify the present marsh vegetation zones and to predict the location and area of future zones on a decade-by- decade basis over the next century at increments of sea level rise on the order of 3 cm/decade (ca. 1 inch). We have developed two scenarios for the model. The first is a steady-state model that uses the historic rate of sea level rise of 3.1 mm/yr to predict marsh areas. The second is a 'global warming' scenario utilizing a conservative IPCC model with an exponentially-increasing rate of sea level rise. Under either scenario, the BNWR is progressively inundated with an expanding core of open water. Although their positions change in the future, the areas of intertidal marsh as well as those of the critical high marsh remain fairly constant until the year 2050. Beyond that time, the low-lying land surface is overtopped by rising sea level and the area is dominated by open water. Our model suggests that wetland habitat in the Blackwater area might be maintained and sustained through a combination of public and private preservation efforts through easements in combination with judicious Federal land acquisition into the predicted areas of suitable marsh formation - but for only the next 50 years. Beyond that time much of this area will become open water.

Estimation of water storage changes in small endorheic lakes in Burabay National Nature Park (Northern Kazakhstan, Central Asia); the effect of climate change and anthropogenic influences

NASA Astrophysics Data System (ADS)

Yapiyev, Vadim; Sagintayev, Zhanay; Verhoef, Anne; Samarkhanov, Kanat; Jumassultanova, Saltanat

2017-04-01

Both climate change and anthropogenic activities contribute to deterioration of terrestrial water resources and ecosystems worldwide. It has been observed in recent decades that water-limited steppe regions of Central Asia are among ecosystems found to exhibit enhanced responses to climate variability. In fact, the largest share of worldwide net loss of permanent water extent is geographically concentrated in the Central Asia and Middle East regions attributed to both climate variability/change and human activities impacts. We used a digital elevation model, digitized bathymetry maps and high resolution Landsat images to estimate the areal water cover extent and volumetric storage changes in small terminal lakes in Burabay National Nature Park (BNNP), located in Northern Central Asia, for the period 2000-2016. Based on the analysis of long-term climatic data from meteorological stations, hydrometeorological network observations as well as regional climate model projections we evaluate the impacts of past thirty years and future climatic conditions on the water balance of BNNP lake catchments. The anthropogenic water consumption was estimated based on data collected at a local water supply company and regulation authorities. One the one hand historical in-situ observations and future climate projections do not show a significant change in precipitation in BNNP. On the other hand both observations and the model demonstrate steadily rising air temperatures in the area. It is concluded that the long-term decline in water levels for most of these lakes can be largely attributed to climate change (but only via changes in air temperature, causing evaporation to exceed precipitation) and not to direct anthropogenic influences such as increased water withdrawals. In addition, the two largest lakes, showing the highest historical water level decline, do not have sufficient water drainage basin area to sustain water levels under increased evaporation rates.

The risk of water scarcity at different levels of global warming

NASA Astrophysics Data System (ADS)

Schewe, Jacob; Sharpe, Simon

2015-04-01

Water scarcity is a threat to human well-being and economic development in many countries today. Future climate change is expected to exacerbate the global water crisis by reducing renewable freshwater resources different world regions, many of which are already dry. Studies of future water scarcity often focus on most-likely, or highest-confidence, scenarios. However, multi-model projections of water resources reveal large uncertainty ranges, which are due to different types of processes (climate, hydrology, human) and are therefore not easy to reduce. Thus, central estimates or multi-model mean results may be insufficient to inform policy and management. Here we present an alternative, risk-based approach. We use an ensemble of multiple global climate and hydrological models to quantify the likelihood of crossing a given water scarcity threshold under different levels of global warming. This approach allows assessing the risk associated with any particular, pre-defined threshold (or magnitude of change that must be avoided), regardless of whether it lies in the center or in the tails of the uncertainty distribution. We show applications of this method on the country and river basin scale, illustrate the effects of societal processes on the resulting risk estimates, and discuss the further potential of this approach for research and stakeholder dialogue.

Dryland Salinity in the North Stirling Land Conservation District, Western Australia: Simulation and Management Options

NASA Astrophysics Data System (ADS)

Gomboso, J.; Ghassemi, F.; Appleyard, S. J.

1997-01-01

The North Stirling Land Conservation District consists of approximately 100,000 hectares north of the Stirling Range National Park, Western Australia. Clearing of land for agriculture occurred in the 1960's and early 1970's. The groundwater is highly saline, and, since clearing, the water table has risen by as much as 12 m; it is now generally less than 3 m below ground level throughout the area. The rise in groundwater levels following clearing and the use of crops and pastures requiring low water use have caused dramatic secondary salinisation over a short period of time. Groundwater flow was simulated with models of steady-state and transient groundwater flow. By incorporating economic simulations with the calibrated transient hydrogeological model, estimates of the expected gross margin losses were made. Three salinity-management strategies were simulated. Results indicate that 1) under the `do-nothing' strategy, future gross margins are expected to decline; 2) under the agronomic strategy, the rate of water-table rise would be reduced and foregone agricultural production losses would be less than the `do-nothing' strategy; and 3) under the agroforestry strategy, the water table is expected to decline in the long term, which would increase future agricultural production levels and, hence, profitability.

Effects of Projected Future Climate Change on Groundwater Recharge and Storage for Two Coastal Aquifers in Guanacaste Province, Costa Rica

NASA Astrophysics Data System (ADS)

Kolb, C.

2017-12-01

Climate change is expected to pose a significant threat to water resources in the future. Guanacaste Province, located in northwestern Costa Rica, has a unique climate that is influenced by the Pacific Ocean and Caribbean Sea, as well as the Central Cordillera mountain range. Although the region experiences a marked rainy season between May and November, the hot, dry summers often stress water resources. Climate change projections suggest increased temperatures and reduced precipitation for the region, which will further stress water supplies. This study focuses on the effects of climate change on groundwater resources for two coastal aquifers, Potrero and Brasilito. The UZF model package coupled with the finite difference groundwater flow model MODFLOW were used to evaluate the effect of climate change on groundwater recharge and storage. A potential evapotranspiration model was used to estimate groundwater infiltration rates used in the MODFLOW model. Climate change projections for temperature, precipitation, and sea level rise were used to develop climate scenarios, which were compared to historical data. Preliminary results indicate that climate change could reduce future recharge, especially during the dry season. Additionally, the coastal aquifers are at increased risk of reduced storage and increased salinization due to the reductions in groundwater recharge and sea level rise. Climate change could also affect groundwater quality in the region, disrupting the ecosystem and impairing a primary source of drinking water.

Continued geophysical logging near the GMH Electronics National Priorities List Superfund site near Roxboro, North Carolina

USGS Publications Warehouse

Antolino, Dominick J.; Chapman, Melinda J.

2017-01-06

The U.S. Geological Survey South Atlantic Water Science Center collected borehole geophysical logs and images and continuous water-level data near the GMH Electronics National Priorities List Superfund site near Roxboro, North Carolina, during December 2012 through July 2015. Previous work by the U.S. Geological Survey South Atlantic Water Science Center at the site involved the collection of borehole geophysical log data in 15 wells, in addition to surface geologic mapping and passive diffusion bag sampling. In a continued effort to assist the U.S. Environmental Protection Agency in developing a conceptual groundwater model to assess current contaminant distribution and future migration of contaminants, more than 900 subsurface features (primarily fracture orientations) in 10 open borehole wells were delineated and continuous water-level data information from 14 monitoring wells within close proximity of the initially drilled boreholes was collected to observe any induced water-level fluctuations during drilling operations

Modeling the effects of climatic and land use changes on phytoplankton and water quality of the largest Turkish freshwater lake: Lake Beyşehir.

PubMed

Bucak, Tuba; Trolle, Dennis; Tavşanoğlu, Ü Nihan; Çakıroğlu, A İdil; Özen, Arda; Jeppesen, Erik; Beklioğlu, Meryem

2018-04-15

Climate change and intense land use practices are the main threats to ecosystem structure and services of Mediterranean lakes. Therefore, it is essential to predict the future changes and develop mitigation measures to combat such pressures. In this study, Lake Beyşehir, the largest freshwater lake in the Mediterranean basin, was selected to study the impacts of climate change and various land use scenarios on the ecosystem dynamics of Mediterranean freshwater ecosystems and the services that they provide. For this purpose, we linked catchment model outputs to the two different processed-based lake models: PCLake and GLM-AED, and tested the scenarios of five General Circulation Models, two Representation Concentration Pathways and three different land use scenarios, which enable us to consider the various sources of uncertainty. Climate change and land use scenarios generally predicted strong future decreases in hydraulic and nutrient loads from the catchment to the lake. These changes in loads translated into alterations in water level as well as minor changes in chlorophyll a (Chl-a) concentrations. We also observed an increased abundance of cyanobacteria in both lake models. Total phosphorus, temperature and hydraulic loading were found to be the most important variables determining cyanobacteria biomass. As the future scenarios revealed only minor changes in Chl-a due to the significant decrease in nutrient loads, our results highlight that reduced nutrient loading in a warming world may play a crucial role in offsetting the effects of temperature on phytoplankton growth. However, our results also showed increased abundance of cyanobacteria in the future may threaten ecosystem integrity and may limit drinking water ecosystem services. In addition, extended periods of decreased hydraulic loads from the catchment and increased evaporation may lead to water level reductions and may diminish the ecosystem services of the lake as a water supply for irrigation and drinking water. Copyright © 2017 Elsevier B.V. All rights reserved.

Water storage in marine sediment and implications for inferences of past global ice volume

NASA Astrophysics Data System (ADS)

Ferrier, K.; Li, Q.; Pico, T.; Austermann, J.

2017-12-01

Changes in past sea level are of wide interest because they provide information on the sensitivity of ice sheets to climate change, and thus inform predictions of future sea-level change. Sea level changes are influenced by many processes, including the storage of water in sedimentary pore space. Here we use a recent extension of gravitationally self-consistent sea-level models to explore the effects of marine sedimentary water storage on the global seawater balance and inferences of past global ice volume. Our analysis suggests that sedimentary water storage can be a significant component of the global seawater budget over the 105-year timescales associated with glacial-interglacial cycles, and an even larger component over longer timescales. Estimates of global sediment fluxes to the oceans suggest that neglecting marine sedimentary water storage may produce meter-scale errors in estimates of peak global mean sea level equivalent (GMSL) during the Last Interglacial (LIG). These calculations show that marine sedimentary water storage can be a significant contributor to the overall effects of sediment redistribution on sea-level change, and that neglecting sedimentary water storage can lead to substantial errors in inferences of global ice volume at past interglacials. This highlights the importance of accounting for the influences of sediment fluxes and sedimentary water storage on sea-level change over glacial-interglacial timescales.

A Water Grid for the UK

NASA Astrophysics Data System (ADS)

Leathard, A.; Fowler, H. J.; Kilsby, C. G.

2009-04-01

Anthropogenically aggravated climate change associated with intensive expansion of the global economy has increased the demand for water whilst simultaneously altering natural variability in its distribution, straining water resources unsustainably and inequitably in many parts of the world, increasing drought risk, and encouraging decision-makers to reconsider the security of water supply. Indeed, in the absence of additional resource development, contemporary planning forecasts imply increased water stress across much of the United Kingdom. The regulatory authorities of the UK currently promote increased efficiency of water delivery and consumption combined with a portfolio of financial instruments as a means of reducing water stress, maintaining present levels of consumer service without significant further exploitation of the environment. Despite an increasingly sophisticated understanding of climate change and its effects, significant uncertainty remains in the quantification of its impacts on the water sector, and questions persist as to the effectiveness of such demand management measures compared to that of more traditional infrastructure improvements. Faced with possible futures provided for by detrimentally over-stressed resources, what opportunities remain for future strategic development in the UK? Is there a single national strategy that is both politically and socially acceptable? This ongoing study aims to evolve robust national adaptation strategies by quantifying the projected impacts of climate change across mainland UK using multi-model and perturbed-physics ensembles of projected future climate, encapsulating uncertainties in a scenario-driven integrated water resources model incorporating socio-economic elements.

Climate variability and demand growth as drivers of water scarcity in the Turkwel river basin: a bottom-up risk assessment of a data-sparse basin in Kenya

NASA Astrophysics Data System (ADS)

Hirpa, F. A.; Dyer, E.; Hope, R.; Dadson, S. J.

2017-12-01

Sustainable water management and allocation are essential for maintaining human well-being, sustaining healthy ecosystems, and supporting steady economic growth. The Turkwel river basin, located in north-western Kenya, experiences a high level of water scarcity due to its arid climate, high rainfall variability, and rapidly growing water demand. However, due to sparse hydro-climatic data and limited literature, the water resources system of the basin has been poorly understood. Here we apply a bottom-up climate risk assessment method to estimate the resilience of the basin's water resources system to growing demand and climate stressors. First, using a water resource system model and historical climate data, we construct a climate risk map that depicts the way in which the system responds to climate change and variability. Then we develop a set of water demand scenarios to identify the conditions that potentially lead to the risk of unmet water demand and groundwater depletion. Finally, we investigate the impact of climate change and variability by stress testing these development scenarios against historically strong El Niño/Southern Oscillation (ENSO) years and future climate projections from multiple Global Circulation Models (GCMs). The results reveal that climate variability and increased water demand are the main drivers of water scarcity in the basin. Our findings show that increases in water demand due to expanded irrigation and population growth exert the strongest influence on the ability of the system to meet water resource supply requirements, and in all cases considered increase the impacts of droughts caused by future climate variability. Our analysis illustrates the importance of combining analysis of future climate risks with other development decisions that affect water resources planning. Policy and investment decisions which maximise water use efficiency in the present day are likely to impart resilience to climate change and variability under a wide range of future scenarios and therefore constitute low regret measures for climate adaptation.

Analysis of High Plains Resource Risk and Economic Impacts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tidwell, Vincent C.; Vargas, Vanessa N; Jones, Shannon M

2016-04-01

The importance of the High Plains Aquifer is broadly recognized as is its vulnerability to continued overuse. T his study e xplore s how continued depletions of the High Plains Aquifer might impact both critical infrastructure and the economy at the local, r egional , and national scale. This analysis is conducted at the county level over a broad geographic region within the states of Kansas and Nebraska. In total , 140 counties that overlie the High Plains Aquifer in these two states are analyzed. The analysis utilizes future climate projections to estimate crop production. Current water use and managementmore » practices are projected into the future to explore their related impact on the High Plains Aquifer , barring any changes in water management practices, regulat ion, or policy. Finally, the impact of declining water levels and even exhaustion of groundwater resources are projected for specific sectors of the economy as well as particular elements of the region's critical infrastructure.« less

Sea-Level Rise and Flood Potential along the California Coast

NASA Astrophysics Data System (ADS)

Delepine, Q.; Leung, C.

2013-12-01

Sea-level rise is becoming an ever-increasing problem in California. Sea-level is expected to rise significantly in the next 100 years, which will raise flood elevations in coastal communities. This will be an issue for private homeowners, businesses, and the state. One study suggests that Venice Beach could lose a total of at least $440 million in tourism spending and tax dollars from flooding and beach erosion if sea level rises 1.4 m by 2100. In addition, several airports, such as San Francisco International Airport, are located in coastal regions that have flooded in the past and will likely be flooded again in the next 30 years, but sea-level rise is expected to worsen the effects of flooding in the coming decades It is vital for coastal communities to understand the risks associated with sea-level rise so that they can plan to adapt to it. By obtaining accurate LiDAR elevation data from the NOAA Digital Coast Website (http://csc.noaa.gov/dataviewer/?keyword=lidar#), we can create flood maps to simulate sea level rise and flooding. The data are uploaded to ArcGIS and contour lines are added for different elevations that represent future coastlines during 100-year flooding. The following variables are used to create the maps: 1. High-resolution land surface elevation data - obtained from NOAA 2. Local mean high water level - from USGS 3. Local 100-year flood water level - from the Pacific Institute 4. Sea-level rise projections for different future dates (2030, 2050, and 2100) - from the National Research Council The values from the last three categories are added to represent sea-level rise plus 100-year flooding. These values are used to make the contour lines that represent the projected flood elevations, which are then exported as KML files, which can be opened in Google Earth. Once these KML files are made available to the public, coastal communities will gain an improved understanding of how flooding and sea-level rise might affect them in the future. This would allow them to plan ahead to reduce the level of risk to homes, industry, and infrastructure San Francisco International Airport will be most likely be flooded in the next 30 years. Blue lines indicate current Mean High Water Levels. Yellow lines indicate the Mean High Water level combined with flood levels for 2030. Green, 2050, and Red lines, 2100

Pathways to sustainable intensification through crop water management

NASA Astrophysics Data System (ADS)

MacDonald, Graham K.; D'Odorico, Paolo; Seekell, David A.

2016-09-01

How much could farm water management interventions increase global crop production? This is the central question posed in a global modelling study by Jägermeyr et al (2016 Environ. Res. Lett. 11 025002). They define the biophysical realm of possibility for future gains in crop production related to agricultural water practices—enhancing water availability to crops and expanding irrigation by reducing non-productive water consumption. The findings of Jägermeyr et al offer crucial insight on the potential for crop water management to sustainably intensify agriculture, but they also provide a benchmark to consider the broader role of sustainable intensification targets in the global food system. Here, we reflect on how the global crop water management simulations of Jägermeyr et al could interact with: (1) farm size at more local scales, (2) downstream water users at the river basin scale, as well as (3) food trade and (4) demand-side food system strategies at the global scale. Incorporating such cross-scale linkages in future research could highlight the diverse pathways needed to harness the potential of farm-level crop water management for a more productive and sustainable global food system.

Translating Uncertain Sea Level Projections Into Infrastructure Impacts Using a Bayesian Framework

NASA Astrophysics Data System (ADS)

Moftakhari, Hamed; AghaKouchak, Amir; Sanders, Brett F.; Matthew, Richard A.; Mazdiyasni, Omid

2017-12-01

Climate change may affect ocean-driven coastal flooding regimes by both raising the mean sea level (msl) and altering ocean-atmosphere interactions. For reliable projections of coastal flood risk, information provided by different climate models must be considered in addition to associated uncertainties. In this paper, we propose a framework to project future coastal water levels and quantify the resulting flooding hazard to infrastructure. We use Bayesian Model Averaging to generate a weighted ensemble of storm surge predictions from eight climate models for two coastal counties in California. The resulting ensembles combined with msl projections, and predicted astronomical tides are then used to quantify changes in the likelihood of road flooding under representative concentration pathways 4.5 and 8.5 in the near-future (1998-2063) and mid-future (2018-2083). The results show that road flooding rates will be significantly higher in the near-future and mid-future compared to the recent past (1950-2015) if adaptation measures are not implemented.

The competing impacts of climate change and nutrient reductions on dissolved oxygen in Chesapeake Bay

NASA Astrophysics Data System (ADS)

Irby, Isaac D.; Friedrichs, Marjorie A. M.; Da, Fei; Hinson, Kyle E.

2018-05-01

The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea level will increase estuarine circulation, reducing residence time in bottom waters and increasing stratification. As a result, oxygen concentrations in bottom waters are projected to increase, while oxygen concentrations at mid-depths (3 < DO < 5 mg L-1) will typically decrease. Changes in precipitation are projected to deliver higher winter and spring freshwater flow and nutrient loads, fueling increased primary production. Together, these multiple climate impacts will lower DO throughout the Chesapeake Bay and negatively impact progress towards meeting water quality standards associated with the Chesapeake Bay Total Maximum Daily Load. However, this research also shows that the potential impacts of climate change will be significantly smaller than improvements in DO expected in response to the required nutrient reductions, especially at the anoxic and hypoxic levels. Overall, increased temperature exhibits the strongest control on the change in future DO concentrations, primarily due to decreased solubility, while sea level rise is expected to exert a small positive impact and increased winter river flow is anticipated to exert a small negative impact.

Effects of remedial grouting on the ground-water flow system at Red Rock Dam near Pella, Iowa

USGS Publications Warehouse

Linhart, S. Mike; Schaap, Bryan D.

2001-01-01

Hydrographs, statistical analysis of waterlevel data, and water-chemistry data suggest that underseepage on the northeast side of the dam has been reduced but not completely eliminated. Some areas appear to have been affected to a greater degree and for a longer period of time than other areas. Future monitoring of water levels, water chemistry, and stable isotopes can aid in the evaluation of the long-term effectiveness of remedial grouting.

Compounding Impacts of Climate Change and Increased Human Water Withdrawal on Urmia Lake Water Availability

NASA Astrophysics Data System (ADS)

Alborzi, A.; Moftakhari, H.; Azaranfar, A.; Mallakpour, I.; Ashraf, B.; AghaKouchak, A.

2017-12-01

In recent decades, climate change and increase in human water withdrawal, combined, have caused ecological degradation in several terminal lakes worldwide. Among them, the shallow and hyper-saline Urmia Lake in Iran has experienced about 6 meters drawdown in lake level and 80% reduction in surface area. Here, we assess the imposed stress on Urmia Basin's water availability and Lake's ecological condition in response to coupled climate change and human-induced water withdrawal. A generalized river basin decision support system model consisting network flow is developed to simulate the basin-lake interactions under a wide range of scenarios. This model explicitly includes water management infrastructure, reservoirs, and irrigation and municipal water use. Studied scenarios represent a wide range of historic climate and water use scenarios including a historical baseline, future increase in water demand, and also improved water efficiency. In this presentation, we show the lake's water level, as a measure of lake's ecological health, under the compounding effects of the climate condition (top-down) and water use (bottom-up) scenarios. This method illustrates what combinations lead to failure in meeting the lake's ecological level.

Paleohydrology of the southern Great Basin, with special reference to water table fluctuations beneath the Nevada Test Site during the late(?) Pleistocene

USGS Publications Warehouse

Winograd, Isaac Judah; Doty, Gene C.

1980-01-01

Knowledge of the magnitude of water-table rise during Pleistocene pluvial climates, and of the resultant shortening of groundwater flow path and reduction in unsaturated zone thickness, is mandatory for a technical evaluation of the Nevada Test Site (NTS) or other arid zone sites as repositories for high-level or transuranic radioactive wastes. The distribution of calcitic veins filling fractures in alluvium, and of tufa deposits between the Ash Meadows spring discharge area and the Nevada Test Site indicates that discharge from the regional Paleozoic carbonate aquifer during the Late( ) Pleistocene pluvial periods may have occurred at an altitude about 50 meters higher than at present and 14 kilometers northeast of Ash Meadows. Use of the underflow equation (relating discharge to transmissivity, aquifer width, and hydraulic gradient), and various assumptions regarding pluvial recharge, transmissivity, and altitude of groundwater base level, suggest possible rises in potentiometric level in the carbonate aquifer of about -90 meters beneath central Frenchman Flat. During Wisconsin time the rise probably did not exceed 30 meters. Water-level rises beneath Frenchman Flat during future pluvials are unlikely to exceed 30 meters and might even be 10 meters lower than modern levels. Neither the cited rise in potentiometric level in the regional carbonate aquifer, nor the shortened flow path during the Late( ) Pleistocene preclude utilization of the NTS as a repository for high-level or transuranic-element radioactive wastes provided other requisite conditions are met as this site. Deep water tables, attendant thick (up to several hundred meter) unsaturated zones, and long groundwater flow paths characterized the region during the Wisconsin Stage and probably throughout the Pleistocene Epoch and are likely to so characterize it during future glacial periods. (USGS)

Effect of sea-level rise on salt water intrusion near a coastal well field in southeastern Florida.

PubMed

Langevin, Christian D; Zygnerski, Michael

2013-01-01

A variable-density groundwater flow and dispersive solute transport model was developed for the shallow coastal aquifer system near a municipal supply well field in southeastern Florida. The model was calibrated for a 105-year period (1900 to 2005). An analysis with the model suggests that well-field withdrawals were the dominant cause of salt water intrusion near the well field, and that historical sea-level rise, which is similar to lower-bound projections of future sea-level rise, exacerbated the extent of salt water intrusion. Average 2005 hydrologic conditions were used for 100-year sensitivity simulations aimed at quantifying the effect of projected rises in sea level on fresh coastal groundwater resources near the well field. Use of average 2005 hydrologic conditions and a constant sea level result in total dissolved solids (TDS) concentration of the well field exceeding drinking water standards after 70 years. When sea-level rise is included in the simulations, drinking water standards are exceeded 10 to 21 years earlier, depending on the specified rate of sea-level rise. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

On the utilization of hydrological modelling for road drainage design under climate and land use change.

PubMed

Kalantari, Zahra; Briel, Annemarie; Lyon, Steve W; Olofsson, Bo; Folkeson, Lennart

2014-03-15

Road drainage structures are often designed using methods that do not consider process-based representations of a landscape's hydrological response. This may create inadequately sized structures as coupled land cover and climate changes can lead to an amplified hydrological response. This study aims to quantify potential increases of runoff in response to future extreme rain events in a 61 km(2) catchment (40% forested) in southwest Sweden using a physically-based hydrological modelling approach. We simulate peak discharge and water level (stage) at two types of pipe bridges and one culvert, both of which are commonly used at Swedish road/stream intersections, under combined forest clear-cutting and future climate scenarios for 2050 and 2100. The frequency of changes in peak flow and water level varies with time (seasonality) and storm size. These changes indicate that the magnitude of peak flow and the runoff response are highly correlated to season rather than storm size. In all scenarios considered, the dimensions of the current culvert are insufficient to handle the increase in water level estimated using a physically-based modelling approach. It also appears that the water level at the pipe bridges changes differently depending on the size and timing of the storm events. The findings of the present study and the approach put forward should be considered when planning investigations on and maintenance for areas at risk of high water flows. In addition, the research highlights the utility of physically-based hydrological models to identify the appropriateness of road drainage structure dimensioning. Copyright © 2014 Elsevier B.V. All rights reserved.

Glaciers and small ice caps in the macro-scale hydrological cycle - an assessment of present conditions and future changes

NASA Astrophysics Data System (ADS)

Lammers, Richard; Hock, Regine; Prusevich, Alexander; Bliss, Andrew; Radic, Valentina; Glidden, Stanley; Grogan, Danielle; Frolking, Steve

2014-05-01

Glacier and small ice cap melt water contributions to the global hydrologic cycle are an important component of human water supply and for sea level rise. This melt water is used in many arid and semi-arid parts of the world for direct human consumption as well as indirect consumption by irrigation for crops, serving as frozen reservoirs of water that supplement runoff during warm and dry periods of summer when it is needed the most. Additionally, this melt water reaching the oceans represents a direct input to sea level rise and therefore accurate estimates of this contribution have profound economic and geopolitical implications. It has been demonstrated that, on the scale of glacierized river catchments, land surface hydrological models can successfully simulate glacier contribution to streamflow. However, at global scales, the implementation of glacier melt in hydrological models has been rudimentary or non-existent. In this study, a global glacier mass balance model is coupled with the University of New Hampshire Water Balance/Transport Model (WBM) to assess recent and projected future glacier contributions to the hydrological cycle over the global land surface (excluding the ice sheets of Greenland and Antarctica). For instance, results of WBM simulations indicate that seasonal glacier melt water in many arid climate watersheds comprises 40 % or more of their discharge. Implicitly coupled glacier and WBM models compute monthly glacier mass changes and resulting runoff at the glacier terminus for each individual glacier from the globally complete Randolph Glacier Inventory including over 200 000 glaciers. The time series of glacier runoff is aggregated over each hydrological modeling unit and delivered to the hydrological model for routing downstream and mixing with non-glacial contribution of runoff to each drainage basin outlet. WBM tracks and uses glacial and non-glacial components of the in-stream water for filling reservoirs, transfers of water between drainage basins (inter-basin hydrological transfers), and irrigation along the global system of rivers with net discharge to the ocean. Climate scenarios from global climate models prepared for IPCC AR5 are used to explore an expected range of possible future glacier outflow variability to estimate the impacts on human use of these valuable waters and their poorly understood net contribution to sea level change.

Using info-Gap Decision Theory for Water Resources Planning Under Severe Uncertainty

NASA Astrophysics Data System (ADS)

Korteling, B.; Brazier, R.; Kapelan, Z.; Dessai, S.

2012-12-01

Water resource managers are required to develop comprehensive water resource plans based on severely uncertain information of the effects of climate change on local hydrology and future socio-economic changes on localised demand. In England and Wales, current water resource planning methodologies include a headroom estimation process that quantifies uncertainty based on only one point of an assumed range of deviations from the expected climate and projected demand 25 years into the future. There are many situations where there is not enough knowledge to be able to estimate a representative probability of occurrence, or to be confident that the tails of an assumed probability distribution will not exhibit unexpected skewness, or that the kurtosis of a distribution differs from the norm. These situations can be considered severely uncertain. Information-Gap decision theory offers a method to sample a wider range of uncertainty than with traditional methods, and as a result, compare the robustness of various water resource management options under conditions of severe uncertainty. A more robust management option is one that delivers the same level of performance as other options at higher levels of uncertainty. A case study is based on a Water Supply Area that encompasses the county of Cornwall in southwest England containing 17 reservoirs and 19 demand nodes. The performance success of management options are evaluated primarily by measures of water availability including a reservoir risk measure that tests the probability and magnitude that strategic reservoir storage levels fall below the drought management curve under adverse conditions and also a safety margin deficit that tests how quickly reservoir levels can return to optimum operating levels in favourable conditions. Multi-Criteria Decision Analysis (MCDA) is used to test the effectiveness of different management options with different weightings for metrics other than water availability including; capital and operating costs, costs to customers, carbon emissions, environmental impact and social acceptability. Findings show that beyond the uncertainty range explored with the traditional headroom method, preference reversals can occur, i.e. some management options that underperform at lower uncertainties, outperform at higher levels of uncertainty. This study also shows that when 50% or more of the population adopts demand side management, efficiency related measures and innovative options such as rainwater collection can perform equally well or better than some supply side options. The additional use of MCDA shifts the focus away from reservoir expansion options that perform best with respect to water availability, to combined strategies that include innovative demand side management actions of rainwater collection and greywater reuse as well as efficiency measures and additional regional transfers. This research illustrates how an Info-Gap based approach can offer a comprehensive picture of potential supply/demand futures and a rich variety of information to support adaptive management of water systems under severe uncertainty.

Evaporation from a temperate closed-basin lake and its impact on present, past, and future water level

NASA Astrophysics Data System (ADS)

Xiao, Ke; Griffis, Timothy J.; Baker, John M.; Bolstad, Paul V.; Erickson, Matt D.; Lee, Xuhui; Wood, Jeffrey D.; Hu, Cheng; Nieber, John L.

2018-06-01

Lakes provide enormous economic, recreational, and aesthetic benefits to citizens. These ecosystem services may be adversely impacted by climate change. In the Twin Cities Metropolitan Area of Minnesota, USA, many lakes have been at historic low levels and water augmentation strategies have been proposed to alleviate the problem. White Bear Lake (WBL) is a notable example. Its water level declined 1.5 m during 2003-2013 for reasons that are not fully understood. This study examined current, past, and future lake evaporation to better understand how climate will impact the water balance of lakes within this region. Evaporation from WBL was measured from July 2014 to February 2017 using two eddy covariance (EC) systems to provide better constraints on the water budget and to investigate the impact of evaporation on lake level. The estimated annual evaporation losses for years 2014 through 2016 were 559 ± 22 mm, 779 ± 81 mm, and 766 ± 11 mm, respectively. The higher evaporation in 2015 and 2016 was caused by the combined effects of larger average daily evaporation and a longer ice-free season. The EC measurements were used to tune the Community Land Model 4 - Lake, Ice, Snow and Sediment Simulator (CLM4-LISSS) to estimate lake evaporation over the period 1979-2016. Retrospective analyses indicate that WBL evaporation increased during this time by about 3.8 mm year-1, which was driven by increased wind speed and lake-surface vapor pressure gradient. Using a business-as-usual greenhouse gas emission scenario (RCP8.5), lake evaporation was modeled forward in time from 2017 to 2100. Annual evaporation is expected to increase by 1.4 mm year-1 over this century, largely driven by lengthening ice-free periods. These changes in ice phenology and evaporation will have important implications for the regional water balance, and water management and water augmentation strategies that are being proposed for these Metropolitan lakes.

Impact analysis of government investment on water projects in the arid Gansu Province of China

NASA Astrophysics Data System (ADS)

Wang, Zhan; Deng, Xiangzheng; Li, Xiubin; Zhou, Qing; Yan, Haiming

In this paper, we introduced three-nested Constant Elasticity of Substitution (CES) production function into a static Computable General Equilibrium (CGE) Model. Through four levels of factor productivity, we constructed three nested production function of land use productivity in the conceptual modeling frameworks. The first level of factor productivity is generated by the basic value-added land. On the second level, factor productivity in each sector is generated by human activities that presents human intervention to the first level of factor productivity. On the third level of factor productivity, water allocation reshapes the non-linear structure of transaction among first and second levels. From the perspective of resource utilization, we examined the economic efficiency of water allocation. The scenario-based empirical analysis results show that the three-nested CES production function within CGE model is well-behaved to present the economy system of the case study area. Firstly, water scarcity harmed economic production. Government investment on water projects in Gansu thereby had impacts on economic outcomes. Secondly, huge governmental financing on water projects bring depreciation of present value of social welfare. Moreover, water use for environment adaptation pressures on water supply. The theoretical water price can be sharply increased due to the increasing costs of factor inputs. Thirdly, water use efficiency can be improved by water projects, typically can be benefited from the expansion of water-saving irrigation areas even in those expanding dry area in Gansu. Therefore, increasing governmental financing on water projects can depreciate present value of social welfare but benefit economic efficiency for future generation.

Potential effects of existing and proposed groundwater withdrawals on water levels and natural groundwater discharge in Snake Valley and surrounding areas, Utah and Nevada

USGS Publications Warehouse

Masbruch, Melissa D.; Brooks, Lynette E.

2017-04-14

Several U.S. Department of Interior (DOI) agencies are concerned about the cumulative effects of groundwater development on groundwater resources managed by, and other groundwater resources of interest to, these agencies in Snake Valley and surrounding areas. The new water uses that potentially concern the DOI agencies include 12 water-right applications filed in 2005, totaling approximately 8,864 acre-feet per year. To date, only one of these applications has been approved and partially developed. In addition, the DOI agencies are interested in the potential effects of three new water-right applications (UT 18-756, UT 18-758, and UT 18-759) and one water-right change application (UT a40687), which were the subject of a water-right hearing on April 19, 2016.This report presents a hydrogeologic analysis of areas in and around Snake Valley to assess potential effects of existing and future groundwater development on groundwater resources, specifically groundwater discharge sites, of interest to the DOI agencies. A previously developed steady-state numerical groundwater-flow model was modified to transient conditions with respect to well withdrawals and used to quantify drawdown and capture (withdrawals that result in depletion) of natural discharge from existing and proposed groundwater withdrawals. The original steady-state model simulates and was calibrated to 2009 conditions. To investigate the potential effects of existing and proposed groundwater withdrawals on the groundwater resources of interest to the DOI agencies, 10 withdrawal scenarios were simulated. All scenarios were simulated for periods of 5, 10, 15, 30, 55, and 105 years from the start of 2010; additionally, all scenarios were simulated to a new steady state to determine the ultimate long-term effects of the withdrawals. Capture maps were also constructed as part of this analysis. The simulations used to develop the capture maps test the response of the system, specifically the reduction of natural discharge, to future stresses at a point in the area represented by the model. In this way, these maps can be used as a tool to determine the source of water to, and potential effects at specific areas from, future well withdrawals.Downward trends in water levels measured in wells indicate that existing groundwater withdrawals in Snake Valley are affecting water levels. The numerical model simulates similar downward trends in water levels; simulated drawdowns in the model, however, are generally less than observed water-level declines. At the groundwater discharge sites of interest to the DOI agencies, simulated drawdowns from existing well withdrawals (projected into the future) range from 0 to about 50 feet. Following the addition of the proposed withdrawals, simulated drawdowns at some sites increase by 25 feet. Simulated drawdown resulting from the proposed withdrawals began in as few as 5 years after 2014 at several of the sites. At the groundwater discharge sites of interest to the DOI agencies, simulated capture of natural discharge resulting from the existing withdrawals ranged from 0 to 87 percent. Following the addition of the proposed withdrawals, simulated capture at several of the sites reached 100 percent, indicating that groundwater discharge at that site would cease. Simulated capture following the addition of the proposed withdrawals increased in as few as 5 years after 2014 at several of the sites.

A Water Grid for the UK

NASA Astrophysics Data System (ADS)

Leathard, A.; Fowler, H. J.; Kilsby, C. G.

2009-12-01

Anthropogenically aggravated climate change associated with intensive expansion of the global economy has increased the demand for water whilst simultaneously altering natural variability in its distribution, straining water resources unsustainably and inequitably in many parts of the world, increasing drought risk, and encouraging decision-makers to reconsider the security of water supply. Indeed, in the absence of additional resource development, contemporary planning forecasts imply increased water stress across much of the United Kingdom. Until recently the regulatory authorities of the UK promoted increased efficiency of water delivery and consumption combined with a portfolio of financial instruments as a means of reducing water stress, maintaining present levels of consumer service without significant further exploitation of the environment. However, despite an increasingly sophisticated understanding of climate change and its effects, significant uncertainty remains in the quantification of its impacts on the water sector, and questions persist as to the effectiveness of such demand management measures compared to that of more traditional infrastructure improvements. Faced with possible futures provided for by detrimentally over-stressed resources, what opportunities remain for future strategic development in the UK? Is there a single national strategy that is both politically and socially acceptable? Do the benefits of national water infrastructure projects outweigh their costs? This ongoing study aims to evolve robust national adaptation strategies by quantifying the projected impacts of climate change across mainland UK using multi-model and perturbed-physics ensembles of projected future climate, encapsulating uncertainties in a scenario-driven integrated water resources model incorporating socio-economic elements.

Hydrologic analysis of Mojave River Basin, California, using electric analog model

USGS Publications Warehouse

Hardt, W.F.

1971-01-01

The water needs of the Mojave River basin will increase because of population and industrial growth. The Mojave Water Agency is responsible for providing sufficient water of good quality for the full economic development of the area. The U.S. Geological Survey suggested an electric analog model of the basin as a predictive tool to aid management. About 1,375 square miles of the alluvial basin was simulated by a passive resistor-capacitor network. The Mojave River, the main source of recharge, was simulated by subdividing the river into 13 reaches, depending on intermittent or perennial flow and on phreatophytes. The water loss to the aquifer was based on records at five gaging stations. The aquifer system depends on river recharge to maintain the water table as most of the ground-water pumping and development is adjacent to the river. The accuracy and reliability of the model was assessed by comparing the water-level changes computed by the model for the period 1930-63 with the changes determined from field data for the same period. The model was used to predict the effects on the physical system by determining basin-wide water-level changes from 1930-2000 under different pumping rates and extremes in flow of the Mojave River. Future pumping was based on the 1960-63 rate, on an increase of 20 percent from this rate, and on population projections to 2000 in the Barstow area. For future predictions, the Mojave River was modeled as average flow based on 1931-65 records and also as high flow, 1937-46, and low flow, 1947-65. Other model runs included water-level change 1930-63 assuming aquifer depletion only and no recharge, effects of a well field pumping 10,000 acre-feet in 4 months north of Victorville and southeast of Yermo, and effects of importing 10,000, 35,000, and 50,800 acre-feet of water per year from the California Water Project into the Mojave River for conveyance downstream.

Risk, Robustness and Water Resources Planning Under Uncertainty

NASA Astrophysics Data System (ADS)

Borgomeo, Edoardo; Mortazavi-Naeini, Mohammad; Hall, Jim W.; Guillod, Benoit P.

2018-03-01

Risk-based water resources planning is based on the premise that water managers should invest up to the point where the marginal benefit of risk reduction equals the marginal cost of achieving that benefit. However, this cost-benefit approach may not guarantee robustness under uncertain future conditions, for instance under climatic changes. In this paper, we expand risk-based decision analysis to explore possible ways of enhancing robustness in engineered water resources systems under different risk attitudes. Risk is measured as the expected annual cost of water use restrictions, while robustness is interpreted in the decision-theoretic sense as the ability of a water resource system to maintain performance—expressed as a tolerable risk of water use restrictions—under a wide range of possible future conditions. Linking risk attitudes with robustness allows stakeholders to explicitly trade-off incremental increases in robustness with investment costs for a given level of risk. We illustrate the framework through a case study of London's water supply system using state-of-the -art regional climate simulations to inform the estimation of risk and robustness.

Results of exploratory drilling at Point MacKenzie, Alaska, 1981

USGS Publications Warehouse

Patrick, Leslie

1981-01-01

The Matanuska-Susitna Borough anticipates industrial development near Point MacKenzie, Alaska. Because little hydrologic information is available for the area, the Borough contracted for the drilling of two test wells. It was found that: Both wells penetrated unconsolidated stratified clay, silt, sand, and gravel; each well penetrated a shallow unconfined and deeper confined aquifers; the water levels in the wells rise and fall with the tide; the chemical analyses indicate that the water quality meets the Alaska Drinking Water Standards, except for slightly high levels of manganese and pH; and the potential for saltwater intrusion should be evaluated as part of future studies. (USGS)

[Fluoride intake through consumption of water from municipal network in the INMA-Gipuzkoa cohort].

PubMed

Jiménez-Zabala, Ana; Santa-Marina, Loreto; Otazua, Mónica; Ayerdi, Mikel; Galarza, Ane; Gallastegi, Mara; Ulibarrena, Enrique; Molinuevo, Amaia; Anabitarte, Asier; Ibarluzea, Jesús

2017-05-22

To estimate fluoride intake through consumption of water from the municipal network in pregnant women and their children from the INMA-Gipuzkoa cohort and to compare these intakes with recommended levels. In Euskadi (Spain), fluoridation of drinking water is compulsory in water supplies for more than 30,000 inhabitants. 575 pregnant women (recruitment, 2006-2008) and 424 4-year-old children (follow-up, 2010-2012) have been included. Fluoride levels in drinking water were obtained from the water consumption information system of the Basque Country (EKUIS). Water consumption habits and socioeconomic variables were obtained by questionnaire. 74.9% and 87.7% of women and children consumed water from the municipal network. Average fluoride levels in fluoridated water were 0.805 (SD: 0.194) mg/L during baseline recruitment and 0.843 (SD: 0.080) mg/L during follow up, at 4 years old of the children. Average and 95th percentile of fluoride intake were 0.015 and 0.026mg/kg per day in women and 0.033 and 0.059mg/kg per day in children. Considering only fluoride provided by drinking water, 8.71% of children living in fluoridated areas exceeded intake level recommended by the European Food Safety Authority, consisting in 0.05mg/kg per day. The results show that ingested levels of fluoride through consumption of municipal water can exceed the recommended levels in children and encourages further studies that will help in fluoridation policies of drinking water in the future. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Comparing CMIP-3 and CMIP-5 climate projections on flooding estimation of Devils Lake of North Dakota, USA

PubMed Central

2018-01-01

Background Water level fluctuations in endorheic lakes are highly susceptible to even slight changes in climate and land use. Devils Lake (DL) in North Dakota, USA is an endorheic system that has undergone multi-decade flooding driven by changes in regional climate. Flooding mitigation strategies have centered on the release of lake water to a nearby river system through artificial outlets, resulting in legal challenges and environmental concerns related to water quality, downstream flooding, species migration, stakeholder opposition, and transboundary water conflicts between the US and Canada. Despite these drawbacks, running outlets would result in low overspill risks in the next 30 years. Methods In this study we evaluated the efficacy of this outlet-based mitigation strategy under scenarios based on the latest IPCC future climate projections. We used the Coupled Model Intercomparison Project CMIP-5 weather patterns from 17 general circulation models (GCMs) obtained under four representative concentration pathways (RCP) scenarios and downscaled to the DL region. Then, we simulated the changes in lake water levels using the soil and water assessment tool based hydrological model of the watershed. We estimated the probability of future flood risks under those scenarios and compared those with previously estimated overspill risks under the CMIP-3 climate. Results The CMIP-5 ensemble projected a mean annual temperature of 5.78 °C and mean daily precipitation of 1.42 mm/day; both are higher than the existing CMIP-3 future estimates of 4.98 °C and 1.40 mm/day, respectively. The increased precipitation and higher temperature resulted in a significant increase of DL’s overspill risks: 24.4–47.1% without release from outlets and 3.5–14.4% even if the outlets are operated at their combined full 17 m3/s capacity. Discussion The modeled increases in overspill risks indicate a greater frequency of water releases through the artificial outlets. Future risk mitigation management should include providing a flood warning signal to local resource managers, and tasking policy makers to identify additional solution measures such as land use management in the upper watershed to mitigate DL’s flooding. PMID:29736343

Comparing CMIP-3 and CMIP-5 climate projections on flooding estimation of Devils Lake of North Dakota, USA.

PubMed

Kharel, Gehendra; Kirilenko, Andrei

2018-01-01

Water level fluctuations in endorheic lakes are highly susceptible to even slight changes in climate and land use. Devils Lake (DL) in North Dakota, USA is an endorheic system that has undergone multi-decade flooding driven by changes in regional climate. Flooding mitigation strategies have centered on the release of lake water to a nearby river system through artificial outlets, resulting in legal challenges and environmental concerns related to water quality, downstream flooding, species migration, stakeholder opposition, and transboundary water conflicts between the US and Canada. Despite these drawbacks, running outlets would result in low overspill risks in the next 30 years. In this study we evaluated the efficacy of this outlet-based mitigation strategy under scenarios based on the latest IPCC future climate projections. We used the Coupled Model Intercomparison Project CMIP-5 weather patterns from 17 general circulation models (GCMs) obtained under four representative concentration pathways (RCP) scenarios and downscaled to the DL region. Then, we simulated the changes in lake water levels using the soil and water assessment tool based hydrological model of the watershed. We estimated the probability of future flood risks under those scenarios and compared those with previously estimated overspill risks under the CMIP-3 climate. The CMIP-5 ensemble projected a mean annual temperature of 5.78 °C and mean daily precipitation of 1.42 mm/day; both are higher than the existing CMIP-3 future estimates of 4.98 °C and 1.40 mm/day, respectively. The increased precipitation and higher temperature resulted in a significant increase of DL's overspill risks: 24.4-47.1% without release from outlets and 3.5-14.4% even if the outlets are operated at their combined full 17 m 3 /s capacity. The modeled increases in overspill risks indicate a greater frequency of water releases through the artificial outlets. Future risk mitigation management should include providing a flood warning signal to local resource managers, and tasking policy makers to identify additional solution measures such as land use management in the upper watershed to mitigate DL's flooding.

Estimated 2008 groundwater potentiometric surface and predevelopment to 2008 water-level change in the Santa Fe Group aquifer system in the Albuquerque area, central New Mexico

USGS Publications Warehouse

Falk, Sarah E.; Bexfield, Laura M.; Anderholm, Scott K.

2011-01-01

The water-supply requirements of the Albuquerque metropolitan area of central New Mexico have historically been met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. Previous studies have indicated that the large quantity of groundwater withdrawal relative to recharge has resulted in water-level declines in the aquifer system throughout the metropolitan area. Analysis of the magnitude and pattern of water-level change can help improve understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies' efforts to minimize future water-level declines and improve sustainability. This report, prepared by the U.S. Geological Survey in cooperation with the Albuquerque Bernalillo County Water Utility Authority, presents the estimated groundwater potentiometric surface during winter (from December to March) of the 2008 water year and the estimated changes in water levels between predevelopment and water year 2008 for the production zone of the Santa Fe Group aquifer system in the Albuquerque and surrounding metropolitan and military areas. Hydrographs from selected wells are included to provide details of historical water-level changes. In general, water-level measurements used for this report were measured in small-diameter observation wells screened over short intervals and were considered to best represent the potentiometric head in the production zone-the interval of the aquifer, about 300 feet below land surface to 1,100 feet or more below land surface, in which production wells generally are screened. Water-level measurements were collected by various local and Federal agencies. The 2008 water year potentiometric surface map was created in a geographic information system, and the change in water-level elevation from predevelopment to water year 2008 was calculated. The 2008 water-level contours indicate that the general direction of groundwater flow is from the Rio Grande towards clusters of production wells in the east, north, and west. Water-level changes from predevelopment to 2008 are variable across the area. Hydrographs from piezometers on the east side of the river generally indicate a trend of decline in the annual highest water level through most of the period of record. Hydrographs from piezometers in the valley near the river and on the west side of the river indicate spatial variability in water-level trends.

Forecasting effects of climate change on Great Lakes fisheries: models that link habitat supply to population dynamics can help

USGS Publications Warehouse

Jones, Michael L.; Shuter, Brian J.; Zhao, Yingming; Stockwell, Jason D.

2006-01-01

Future changes to climate in the Great Lakes may have important consequences for fisheries. Evidence suggests that Great Lakes air and water temperatures have risen and the duration of ice cover has lessened during the past century. Global circulation models (GCMs) suggest future warming and increases in precipitation in the region. We present new evidence that water temperatures have risen in Lake Erie, particularly during summer and winter in the period 1965–2000. GCM forecasts coupled with physical models suggest lower annual runoff, less ice cover, and lower lake levels in the future, but the certainty of these forecasts is low. Assessment of the likely effects of climate change on fish stocks will require an integrative approach that considers several components of habitat rather than water temperature alone. We recommend using mechanistic models that couple habitat conditions to population demographics to explore integrated effects of climate-caused habitat change and illustrate this approach with a model for Lake Erie walleye (Sander vitreum). We show that the combined effect on walleye populations of plausible changes in temperature, river hydrology, lake levels, and light penetration can be quite different from that which would be expected based on consideration of only a single factor.

Quantifying the combined effects of land use and climate changes on stream flow and nutrient loads: A modelling approach in the Odense Fjord catchment (Denmark).

PubMed

Molina-Navarro, Eugenio; Andersen, Hans E; Nielsen, Anders; Thodsen, Hans; Trolle, Dennis

2018-04-15

Water pollution and water scarcity are among the main environmental challenges faced by the European Union, and multiple stressors compromise the integrity of water resources and ecosystems. Particularly in lowland areas of northern Europe, high population density, flood protection and, especially, intensive agriculture, are important drivers of water quality degradation. In addition, future climate and land use changes may interact, with uncertain consequences for water resources. Modelling approaches have become essential to address water issues and to evaluate ecosystem management. In this work, three multi-stressor future storylines combining climatic and socio-economic changes, defined at European level, have been downscaled for the Odense Fjord catchment (Denmark), giving three scenarios: High-Tech agriculture (HT), Agriculture for Nature (AN) and Market-Driven agriculture (MD). The impacts of these scenarios on water discharge and inorganic and organic nutrient loads to the streams have been simulated using the Soil and Water Assessment Tool (SWAT). The results revealed that the scenario-specific climate inputs were most important when simulating hydrology, increasing river discharge in the HT and MD scenarios (which followed the high emission 8.5 representative concentration pathway, RCP), while remaining stable in the AN scenario (RCP 4.5). Moreover, discharge was the main driver of changes in organic nutrients and inorganic phosphorus loads that consequently increased in a high emission scenario. Nevertheless, both land use (via inputs of fertilizer) and climate changes affected the nitrate transport. Different levels of fertilization yielded a decrease in the nitrate load in AN and an increase in MD. In HT, however, nitrate losses remained stable because the fertilization decrease was counteracted by a flow increase. Thus, our results suggest that N loads will ultimately depend on future land use and management in an interaction with climate changes, and this knowledge is of utmost importance for the achievement of European environmental policy goals. Copyright © 2017 Elsevier B.V. All rights reserved.

Hydrologic and water quality impacts of biofuel feedstock production in the Ohio River Basin

DOE PAGES

Demissie, Yonas; Yan, Eugene; Wu, May

2017-07-10

Our study addresses the uncertainties related to potential changes in land use and management and associated impacts on hydrology and water quality resulting from increased production of biofuel from the conventional and cellulosic feedstock. The Soil Water Assessment Tool (SWAT) was then used to assess the impacts on regional and field scale evapotranspiration, soil moisture content, stream flow, sediment, and nutrient loadings in the Ohio River Basin. The model incorporates spatially and temporally detailed hydrologic, climate and agricultural practice data that are pertinent to simulate biofuel feedstock production, watershed hydrology and water quality. Three future biofuel production scenarios in themore » region were considered, including a feedstock projection from the DOE Billion-Ton (BT2) Study, a change in corn rotations to continuous corn, and harvest of 50% corn stover. The impacts were evaluated on the basis of relative changes in hydrology and water quality from historical baseline and future business-as-usual conditions of the basin. The overall impact on water quality is an order of magnitude higher than the impact on hydrology. For all the three future scenarios, the sub-basin results indicated an overall increase in annual evapotranspiration of up to 6%, a decrease in runoff up to 10% and minimal change in soil moisture. The sediment and phosphorous loading at both regional and field levels increased considerably (up to 40–90%) for all the biofuel feedstock scenario considered, while the nitrogen loading increased up to 45% in some regions under the BT2 Study scenario, decreased up to 10% when corn are grown continuously instead of in rotations, and changed minimally when 50% of the stover are harvested. Field level analyses revealed significant variability in hydrology and water quality impacts that can further be used to identify suitable locations for the feedstock productions without causing major impacts on water quantity and quality.« less

Hydrologic and water quality impacts of biofuel feedstock production in the Ohio River Basin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demissie, Yonas; Yan, Eugene; Wu, May

Our study addresses the uncertainties related to potential changes in land use and management and associated impacts on hydrology and water quality resulting from increased production of biofuel from the conventional and cellulosic feedstock. The Soil Water Assessment Tool (SWAT) was then used to assess the impacts on regional and field scale evapotranspiration, soil moisture content, stream flow, sediment, and nutrient loadings in the Ohio River Basin. The model incorporates spatially and temporally detailed hydrologic, climate and agricultural practice data that are pertinent to simulate biofuel feedstock production, watershed hydrology and water quality. Three future biofuel production scenarios in themore » region were considered, including a feedstock projection from the DOE Billion-Ton (BT2) Study, a change in corn rotations to continuous corn, and harvest of 50% corn stover. The impacts were evaluated on the basis of relative changes in hydrology and water quality from historical baseline and future business-as-usual conditions of the basin. The overall impact on water quality is an order of magnitude higher than the impact on hydrology. For all the three future scenarios, the sub-basin results indicated an overall increase in annual evapotranspiration of up to 6%, a decrease in runoff up to 10% and minimal change in soil moisture. The sediment and phosphorous loading at both regional and field levels increased considerably (up to 40–90%) for all the biofuel feedstock scenario considered, while the nitrogen loading increased up to 45% in some regions under the BT2 Study scenario, decreased up to 10% when corn are grown continuously instead of in rotations, and changed minimally when 50% of the stover are harvested. Field level analyses revealed significant variability in hydrology and water quality impacts that can further be used to identify suitable locations for the feedstock productions without causing major impacts on water quantity and quality.« less

Objective Assessment of Groundwater Resources for the Isle of Wight, UK

NASA Astrophysics Data System (ADS)

Simpson, M.; Butler, A. P.; McIntyre, N.

2012-12-01

Water resources are of crucial importance to the UK, and are essential to agriculture and industry as well as for domestic usage. A combination of factors - population growth, climate change and increasing regulatory restriction - will alter water availability over the next fifty years, potentially leading to shortages. Groundwater systems, representing 60% of available water in the southern UK, are typically conceptualised through geological interpretation, resulting in skilful and widely used systems models. Where these models are not successful, alternative approaches to groundwater resource assessments are required. A process for objectively modelling groundwater systems from borehole level observation data is presented, along with a methodology for incorporating climate change and population growth forecasts into an assessment of future water availability. The objective assessment described is a three stage process. Firstly, the observation data can be associated into groups, in order to best represent the water table response and thus identify units with consistent storage coefficient and transport process, analogous to varying aquifer media. Here this is achieved through the use of cluster analysis, applying various distance metrics to observation variances and incorporating spatial displacement. Secondly, the resulting groups are used to generate interpolated surfaces of mean water table level. A series of interpolative methods, including stochastic approaches, are applied and cross-validated to generate the most credible groundwater surface. Thirdly, the presence and influence of spatial and temporal anomalies such as groundwater abstraction points are identified through examination of observations furthest from the final interpolated groundwater surface. This groundwater systems model can then be incorporated into a groundwater/surface model relating rainfall to water table level and river flow, which in turn is used in conjunction with state-of-the-art climate projections and population change forecasts to generate projections of change for future scenarios. A case study illustrating the use of this methodology is presented. The Isle of Wight, a small island off the south coast of England with a population of 140,000, is exceptionally water stressed by UK standards and currently dependent on mainland transfers. These transfers are under review due to environmental pressure on the neighbouring county of Hampshire. Alongside this, a high population growth rate and the southerly location make the Isle of Wight the most likely part of the UK to be affected by reduced water availability. Lower Greensands and Chalk aquifer systems provide most of the island's non-imported water, yet these remain poorly understood. The principle reason for this is the exceptionally complex geology, a result of the island's location at the convergence of two asymmetric anticlinal structures and, in the case of the Lower Greensand group, multiple layers of alternating aquiferous and non-aquiferous material. A statistical assessment of borehole data may provide evidence for groundwater processes where direct lithological analysis is not appropriate. Through development of a credible groundwater systems model and sensible projections of future water availability, critical information can be provided to influence future water management policy.

Genome-wide transcriptome analysis of soybean primary root under varying water-deficit conditions.

PubMed

Song, Li; Prince, Silvas; Valliyodan, Babu; Joshi, Trupti; Maldonado dos Santos, Joao V; Wang, Jiaojiao; Lin, Li; Wan, Jinrong; Wang, Yongqin; Xu, Dong; Nguyen, Henry T

2016-01-15

Soybean is a major crop that provides an important source of protein and oil to humans and animals, but its production can be dramatically decreased by the occurrence of drought stress. Soybeans can survive drought stress if there is a robust and deep root system at the early vegetative growth stage. However, little is known about the genome-wide molecular mechanisms contributing to soybean root system architecture. This study was performed to gain knowledge on transcriptome changes and related molecular mechanisms contributing to soybean root development under water limited conditions. The soybean Williams 82 genotype was subjected to very mild stress (VMS), mild stress (MS) and severe stress (SS) conditions, as well as recovery from the severe stress after re-watering (SR). In total, 6,609 genes in the roots showed differential expression patterns in response to different water-deficit stress levels. Genes involved in hormone (Auxin/Ethylene), carbohydrate, and cell wall-related metabolism (XTH/lipid/flavonoids/lignin) pathways were differentially regulated in the soybean root system. Several transcription factors (TFs) regulating root growth and responses under varying water-deficit conditions were identified and the expression patterns of six TFs were found to be common across the stress levels. Further analysis on the whole plant level led to the finding of tissue-specific or water-deficit levels specific regulation of transcription factors. Analysis of the over-represented motif of different gene groups revealed several new cis-elements associated with different levels of water deficit. The expression patterns of 18 genes were confirmed byquantitative reverse transcription polymerase chain reaction method and demonstrated the accuracy and effectiveness of RNA-Seq. The primary root specific transcriptome in soybean can enable a better understanding of the root response to water deficit conditions. The genes detected in root tissues that were associated with key hormones, carbohydrates, and cell wall-related metabolism could play a vital role in achieving drought tolerance and could be promising candidates for future functional characterization. TFs involved in the soybean root and at the whole plant level could be used for future network analysis between TFs and cis-elements. All of these findings will be helpful in elucidating the molecular mechanisms associated with water stress responses in soybean roots.

Effects of human management on black carbon sorption/desorption during a water transfer project: Recognizing impacts and identifying mitigation possibilities.

PubMed

Hao, Rong; Zhang, Jinliang; Wang, Peichao; Hu, Ronggui; Song, Yantun; Wu, Yupeng; Qiu, Guohong

2018-05-15

Water resources management is an important public concern. In this study, we examined the extent of sorption/desorption of trace pollutants to soil black carbon (BC) in the water level fluctuation zone (WLFZ) of the middle route of the South to North Water Transfer Project in China. In addition, we investigated the main management measures affecting these processes during the project. The results showed that the pseudo second-order model adequately describes the sorption/desorption of phenanthrene on the soil BC in the WLFZ. Water level fluctuation may indirectly influenced BC sorption/desorption by altering water chemistry. Water level residence time had negative effects on BC sorption in short-term experiments (days to months), but the impact gradually diminished with increased residence time. The results suggested that long-term field monitoring of water chemistry is urgent. During the initial period of water transfer, delaying the water supplies as drinking water source or directly irrigating crops could mitigate the adverse impacts. Future research should focus on the water-soluble products of BC degradation. The findings of this study should be useful in improving sustainable management of water resources for water transfer projects. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaporation from a temperate closed-basin lake and its impact on present, past, and future water level

NASA Astrophysics Data System (ADS)

Xiao, K.; Griffis, T. J.; Baker, J. M.; Bolstad, P. V.; Erickson, M. D.; Lee, X.; Wood, J. D.; Hu, C.

2017-12-01

Lakes provide enormous economic, recreational, and aesthetic benefits to citizens. These ecosystem services may be adversely impacted by climate change. In the Twin Cities Metropolitan Area of Minnesota, USA, many lakes have been at historic low levels and water augmentation strategies have been proposed to alleviate the problem. For example, the water level of White Bear Lake (WBL) declined 1.5 m during 2003-2013 for reasons that are not fully understood. This study examined current, past, and future lake evaporation to better understand how climate will impact the water balance of lakes within this region. Evaporation from WBL was measured from July 2014 to February 2017 using two eddy covariance (EC) systems to provide better constraints on the water budget and to investigate the impact of evaporation on lake level. The annual evaporation for years 2014 through 2016 were 559±22 mm, 779±81 mm, and 766±11 mm, respectively. The larger evaporation in 2015 and 2016 was caused by the combined effects of larger average daily evaporation and a longer ice-free season. The EC measurements were used to tune the Community Land Model 4 - Lake, Ice, Snow and Sediment Simulator (CLM4-LISSS) to estimate lake evaporation over the period 1979-2016. Retrospective analyses indicated that WBL evaporation increased by about 3.8 mm yr-1. Mass balance analysis implied that the lake level declines at WBL during 1986-1990 and 2003-2012 were mainly caused by the coupled low precipitation and high evaporation. Using a business-as-usual greenhouse gas emission scenario (RCP8.5), lake evaporation was modeled forward in time from 2017 to 2100. Annual evaporation is expected to increase by 1.4 mm yr-1 over this century, which is largely driven by lengthening ice-free periods. These changes in ice phenology and evaporation will have important implications for the regional water balance, and water management and water augmentation strategies that are being proposed for these Metropolitan lakes.

Natural fluoride levels in the drinking water, water fluoridation and estimated risk of dental fluorosis in a tropical region of Brazil.

PubMed

Sampaio, Fábio Correia; Silva, Fábia Danielle; Silva, Andréa Cristina; Machado, Ana Thereza; de Araújo, Demétrius Antônio; de Sousa, Erik Melo

2010-01-01

The aim of the present study was to determine the natural fluoride levels in the drinking water supplies of a tropical area of Brazil to identify the cities at risk of high prevalence of dental fluorosis and to provide data for future water fluoridation projects in the region. The present study was carried out in Paraíba, in the north-eastern region of Brazil. A total of 223 cities were selected, and local health workers were instructed to collect three samples of drinking water: one from the main public water supply and the other two from a public or residential tap with the same water source. Fluoride analyses were carried out in duplicate using a fluoride-specific electrode coupled to an ion analyser. A total of 167 cities (75%) provided water samples for analysis. Fluoride levels ranged from 0.1 to 1.0 ppm (mg/l). Samples from most of the cities (n = 163, 73%) presented low levels of fluoride (< 0.5 mg/l). Samples from three cities (a total estimate of 28,222 inhabitants exposed) presented 'optimum' fluoride levels (0.6 to 0.8 mg/l). Samples from one city (16,724 inhabitants) with 1.0 mg/l of fluoride in the water were above the recommended level (0.7 mg/l) for the local temperature. It can be concluded that the cities in this area of Brazil presented low natural fluoride levels in the drinking water and could implement controlled water fluoridation projects when technical requirements are accomplished. A high or a moderate prevalence of dental fluorosis due to the intake of natural fluoride in the drinking water is likely to take place in one city only.

Climatic water deficit, tree species ranges, and climate change in Yosemite National Park

USGS Publications Warehouse

Lutz, James A.; Van Wagtendonk, Jan W.; Franklin, Jerry F.

2010-01-01

Aim  (1) To calculate annual potential evapotranspiration (PET), actual evapotranspiration (AET) and climatic water deficit (Deficit) with high spatial resolution; (2) to describe distributions for 17 tree species over a 2300-m elevation gradient in a 3000-km2 landscape relative to AET and Deficit; (3) to examine changes in AET and Deficit between past (c. 1700), present (1971–2000) and future (2020–49) climatological means derived from proxies, observations and projections; and (4) to infer how the magnitude of changing Deficit may contribute to changes in forest structure and composition.Location  Yosemite National Park, California, USA.Methods  We calculated the water balance within Yosemite National Park using a modified Thornthwaite-type method and correlated AET and Deficit with tree species distribution. We used input data sets with different spatial resolutions parameterized for variation in latitude, precipitation, temperature, soil water-holding capacity, slope and aspect. We used climate proxies and climate projections to model AET and Deficit for past and future climate. We compared the modelled future water balance in Yosemite with current species water-balance ranges in North America.Results  We calculated species climatic envelopes over broad ranges of environmental gradients – a range of 310 mm for soil water-holding capacity, 48.3°C for mean monthly temperature (January minima to July maxima), and 918 mm yr−1 for annual precipitation. Tree species means were differentiated by AET and Deficit, and at higher levels of Deficit, species means were increasingly differentiated. Modelled Deficit for all species increased by a mean of 5% between past (c. 1700) and present (1971–2000). Projected increases in Deficit between present and future (2020–49) were 23% across all plots.Main conclusions  Modelled changes in Deficit between past, present and future climate scenarios suggest that recent past changes in forest structure and composition may accelerate in the future, with species responding individualistically to further declines in water availability. Declining water availability may disproportionately affect Pinus monticola and Tsuga mertensiana. Fine-scale heterogeneity in soil water-holding capacity, aspect and slope implies that plant water balance may vary considerably within the grid cells of kilometre-scale climate models. Sub-grid-cell soil and topographical data can partially compensate for the lack of spatial heterogeneity in gridded climate data, potentially improving vegetation-change projections in mountainous landscapes with heterogeneous topography.

Designing Dynamic Adaptive Policy Pathways using Many-Objective Robust Decision Making

NASA Astrophysics Data System (ADS)

Kwakkel, Jan; Haasnoot, Marjolijn

2017-04-01

Dealing with climate risks in water management requires confronting a wide variety of deeply uncertain factors, while navigating a many dimensional space of trade-offs amongst objectives. There is an emerging body of literature on supporting this type of decision problem, under the label of decision making under deep uncertainty. Two approaches within this literature are Many-Objective Robust Decision Making, and Dynamic Adaptive Policy Pathways. In recent work, these approaches have been compared. One of the main conclusions of this comparison was that they are highly complementary. Many-Objective Robust Decision Making is a model based decision support approach, while Dynamic Adaptive Policy Pathways is primarily a conceptual framework for the design of flexible strategies that can be adapted over time in response to how the future is actually unfolding. In this research we explore this complementarity in more detail. Specifically, we demonstrate how Many-Objective Robust Decision Making can be used to design adaptation pathways. We demonstrate this combined approach using a water management problem, in the Netherlands. The water level of Lake IJselmeer, the main fresh water resource of the Netherlands, is currently managed through discharge by gravity. Due to climate change, this won't be possible in the future, unless water levels are changed. Changing the water level has undesirable flood risk and spatial planning consequences. The challenge is to find promising adaptation pathways that balance objectives related to fresh water supply, flood risk, and spatial issues, while accounting for uncertain climatic and land use change. We conclude that the combination of Many-Objective Robust Decision Making and Dynamic Adaptive Policy Pathways is particularly suited for dealing with deeply uncertain climate risks.

Effects of climate change on water abstraction restrictions for irrigation during droughts - The UK case

NASA Astrophysics Data System (ADS)

Rey Vicario, D.; Holman, I.

2016-12-01

The use of water for irrigation and on-farm reservoir filling is globally important for agricultural production. In humid climates, like the UK, supplemental irrigation can be critical to buffer the effects of rainfall variability and to achieve high quality crops. Given regulatory efforts to secure sufficient environmental river flows and meet rising water demands due to population growth and climate change, increasing water scarcity is likely to compound the drought challenges faced by irrigated agriculture in this region. Currently, water abstraction from surface waters for agricultural irrigation can be restricted by the Environment Agency during droughts under Section 57 of the Water Resources Act (1991), based on abnormally low river flow levels and rainfall forecast, causing significant economic impacts on irrigated agricultural production. The aim of this study is to assess the impact that climate change may have on agricultural abstraction in the UK within the context of the abstraction restriction triggers currently in place. These triggers have been applied to the `Future Flows hydrology' database to assess the likelihood of increasing restrictions on agricultural abstraction in the future by comparing the probability of voluntary and compulsory restrictions in the baseline (1961-1990) and future period (2071-2098) for 282 catchments throughout the whole of the UK. The results of this study show a general increase in the probability of future agricultural irrigation abstraction restrictions in the UK in the summer, particularly in the South West, although there is significant variability between the 11 ensemble members. The results also indicate that UK winters are likely to become wetter in the future, although in some catchments the probability of abstraction restriction in the reservoir refilling winter months (November-February) could increase slightly. An increasing frequency of drought events due to climate change is therefore likely to lead to more water abstraction restrictions, increasing the need for irrigators to adapt their businesses to increase drought resilience and hence food security.

Country-level assessment of future risk of water scarcity in Europe

NASA Astrophysics Data System (ADS)

Garrote, Luis; Iglesias, Ana; Granados, Alfredo

2018-06-01

A methodology for regional assessment of current and future water availability in Europe is presented in this study. The methodology is based on a proposed indicator of risk of water scarcity based on the projections of runoff and water availability for European countries. The risk of water scarcity is the combined result of hydrological processes, which determine streamflow in natural conditions, and human intervention, which determines water management using the available hydraulic infrastructure and establishes water supply conditions through operating rules. Model results show that changes in runoff and availability obtained for individual GCM projections can be large and even contradictory. These heterogeneous results are summarized in the water scarcity risk index, a global value that accounts for the results obtained with the ensemble of model results and emission scenarios. The countries at larger risk are (in this order) Spain, Portugal, Macedonia, Greece, Bulgaria, Albania, France and Italy. They are mostly Mediterranean countries already exposed to significant water scarcity problems. There are countries, like Slovakia, Ireland, Belgium, Luxembourg, Croatia and Romania, with mild risk. Northern Arctic countries, like Sweden, Finland, Norway and Russia, show a robust however mild increase in water availability.

Quantifying an aquifer nitrate budget and future nitrate discharge using field data from streambeds and well nests

NASA Astrophysics Data System (ADS)

Gilmore, Troy E.; Genereux, David P.; Solomon, D. Kip; Farrell, Kathleen M.; Mitasova, Helena

2016-11-01

Novel groundwater sampling (age, flux, and nitrate) carried out beneath a streambed and in wells was used to estimate (1) the current rate of change of nitrate storage, dSNO3/dt, in a contaminated unconfined aquifer, and (2) future [NO3-]FWM (the flow-weighted mean nitrate concentration in groundwater discharge) and fNO3 (the nitrate flux from aquifer to stream). Estimates of dSNO3/dt suggested that at the time of sampling (2013) the nitrate storage in the aquifer was decreasing at an annual rate (mean = -9 mmol/m2yr) equal to about one-tenth the rate of nitrate input by recharge. This is consistent with data showing a slow decrease in the [NO3-] of groundwater recharge in recent years. Regarding future [NO3-]FWM and fNO3, predictions based on well data show an immediate decrease that becomes more rapid after ˜5 years before leveling out in the early 2040s. Predictions based on streambed data generally show an increase in future [NO3-]FWM and fNO3 until the late 2020s, followed by a decrease before leveling out in the 2040s. Differences show the potential value of using information directly from the groundwater—surface water interface to quantify the future impact of groundwater nitrate on surface water quality. The choice of denitrification kinetics was similarly important; compared to zero-order kinetics, a first-order rate law levels out estimates of future [NO3-]FWM and fNO3 (lower peak, higher minimum) as legacy nitrate is flushed from the aquifer. Major fundamental questions about nonpoint-source aquifer contamination can be answered without a complex numerical model or long-term monitoring program.

Fusion of radar and optical data for mapping and monitoring of water bodies

NASA Astrophysics Data System (ADS)

Jenerowicz, Agnieszka; Siok, Katarzyn

2017-10-01

Remote sensing techniques owe their great popularity to the possibility to obtain of rapid, accurate and information over large areas with optimal time, spatial and spectral resolutions. The main areas of interest for remote sensing research had always been concerned with environmental studies, especially water bodies monitoring. Many methods that are using visible and near- an infrared band of the electromagnetic spectrum had been already developed to detect surface water reservoirs. Moreover, the usage of an image obtained in visible and infrared spectrum allows quality monitoring of water bodies. Nevertheless, retrieval of water boundaries and mapping surface water reservoirs with optical sensors is still quite demanding. Therefore, the microwave data could be the perfect complement to data obtained with passive optical sensors to detect and monitor aquatic environment especially surface water bodies. This research presents the methodology to detect water bodies with open- source satellite imagery acquired with both optical and microwave sensors. The SAR Sentinel- 1 and multispectral Sentinel- 2 imagery were used to detect and monitor chosen reservoirs in Poland. In the research Level, 1 Sentinel- 2 data and Level 1 SAR images were used. SAR data were mainly used for mapping water bodies. Next, the results of water boundaries extraction with Sentinel-1 data were compared to results obtained after application of modified spectral indices for Sentinel- 2 data. The multispectral optical data can be used in the future for the evaluation of the quality of the reservoirs. Preliminary results obtained in the research had shown, that the fusion of data obtained with optical and microwave sensors allow for the complex detection of water bodies and could be used in the future quality monitoring of water reservoirs.

How Sustainable is Groundwater Abstraction? A Global Assessment.

NASA Astrophysics Data System (ADS)

de Graaf, I.; Van Beek, R.; Gleeson, T. P.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

2016-12-01

Groundwater is the world's largest accessible freshwater resource and is of critical importance for irrigation, and thus for global food security. For regions with high demands, groundwater abstractions often exceed recharge and persistent groundwater depletion occurs. The direct effects of depletion are falling groundwater levels, increased pumping costs, land subsidence, and reduced baseflows to rivers. Water demands are expected to increase further due to growing population, economic development, and climate change, posing the urgent question how sustainable current water abstractions are worldwide and where and when these abstractions approach conceivable economic and environmental limits. In this study we estimated trends over 1960-2100 in groundwater levels, resulting from changes in demand and climate. We explored the limits of groundwater abstraction by predicting where and when groundwater levels drop that deep that groundwater gets unattainable for abstraction (economic limit) or, that groundwater baseflows to rivers drop below environmental requirements (environmental limit). We used a global hydrological model coupled to a groundwater model, meaning lateral groundwater flows, river infiltration and drainage, and infiltration and capillary-rise are simulated dynamically. Historical data and projections are used to prescribe water demands and climate forcing to the model. For the near future we used RCP8.5 and applied globally driest, average, and wettest GCM to test climate sensitivity. Results show that in general environmental limits are reached before economic limits, for example starting as early as the 1970s compared to the 1980s for economic limits in the upper Ganges basin. Economic limits are mostly related to regions with depletion, while environmental limits are reached also in regions were groundwater and surface water withdrawals are significant but depletion is not taking place (yet), for example in Spain and Portugal. In the near future, more regions will reach their limits, current depletion regions will expand and new regions experiencing depletion will develop. Regionally the increasing level of groundwater stress, economically and environmentally, will be an important factor in future economic development and could lead to socio-economic tension.

How Sustainable is Groundwater Abstraction? A Global Assessment.

NASA Astrophysics Data System (ADS)

de Graaf, I.; Van Beek, R.; Gleeson, T. P.; Sutanudjaja, E.; Wada, Y.; Bierkens, M. F.

2017-12-01

Groundwater is the world's largest accessible freshwater resource and is of critical importance for irrigation, and thus for global food security. For regions with high demands, groundwater abstractions often exceed recharge and persistent groundwater depletion occurs. The direct effects of depletion are falling groundwater levels, increased pumping costs, land subsidence, and reduced baseflows to rivers. Water demands are expected to increase further due to growing population, economic development, and climate change, posing the urgent question how sustainable current water abstractions are worldwide and where and when these abstractions approach conceivable economic and environmental limits. In this study we estimated trends over 1960-2100 in groundwater levels, resulting from changes in demand and climate. We explored the limits of groundwater abstraction by predicting where and when groundwater levels drop that deep that groundwater gets unattainable for abstraction (economic limit) or, that groundwater baseflows to rivers drop below environmental requirements (environmental limit). We used a global hydrological model coupled to a groundwater model, meaning lateral groundwater flows, river infiltration and drainage, and infiltration and capillary-rise are simulated dynamically. Historical data and projections are used to prescribe water demands and climate forcing to the model. For the near future we used RCP8.5 and applied globally driest, average, and wettest GCM to test climate sensitivity. Results show that in general environmental limits are reached before economic limits, for example starting as early as the 1970s compared to the 1980s for economic limits in the upper Ganges basin. Economic limits are mostly related to regions with depletion, while environmental limits are reached also in regions were groundwater and surface water withdrawals are significant but depletion is not taking place (yet), for example in Spain and Portugal. In the near future, more regions will reach their limits, current depletion regions will expand and new regions experiencing depletion will develop. Regionally the increasing level of groundwater stress, economically and environmentally, will be an important factor in future economic development and could lead to socio-economic tension.

Optimizing conjunctive use of surface water and groundwater resources with stochastic dynamic programming

NASA Astrophysics Data System (ADS)

Davidsen, Claus; Liu, Suxia; Mo, Xingguo; Rosbjerg, Dan; Bauer-Gottwein, Peter

2014-05-01

Optimal management of conjunctive use of surface water and groundwater has been attempted with different algorithms in the literature. In this study, a hydro-economic modelling approach to optimize conjunctive use of scarce surface water and groundwater resources under uncertainty is presented. A stochastic dynamic programming (SDP) approach is used to minimize the basin-wide total costs arising from water allocations and water curtailments. Dynamic allocation problems with inclusion of groundwater resources proved to be more complex to solve with SDP than pure surface water allocation problems due to head-dependent pumping costs. These dynamic pumping costs strongly affect the total costs and can lead to non-convexity of the future cost function. The water user groups (agriculture, industry, domestic) are characterized by inelastic demands and fixed water allocation and water supply curtailment costs. As in traditional SDP approaches, one step-ahead sub-problems are solved to find the optimal management at any time knowing the inflow scenario and reservoir/aquifer storage levels. These non-linear sub-problems are solved using a genetic algorithm (GA) that minimizes the sum of the immediate and future costs for given surface water reservoir and groundwater aquifer end storages. The immediate cost is found by solving a simple linear allocation sub-problem, and the future costs are assessed by interpolation in the total cost matrix from the following time step. Total costs for all stages, reservoir states, and inflow scenarios are used as future costs to drive a forward moving simulation under uncertain water availability. The use of a GA to solve the sub-problems is computationally more costly than a traditional SDP approach with linearly interpolated future costs. However, in a two-reservoir system the future cost function would have to be represented by a set of planes, and strict convexity in both the surface water and groundwater dimension cannot be maintained. The optimization framework based on the GA is still computationally feasible and represents a clean and customizable method. The method has been applied to the Ziya River basin, China. The basin is located on the North China Plain and is subject to severe water scarcity, which includes surface water droughts and groundwater over-pumping. The head-dependent groundwater pumping costs will enable assessment of the long-term effects of increased electricity prices on the groundwater pumping. The coupled optimization framework is used to assess realistic alternative development scenarios for the basin. In particular the potential for using electricity pricing policies to reach sustainable groundwater pumping is investigated.

Observations and a linear model of water level in an interconnected inlet-bay system

NASA Astrophysics Data System (ADS)

Aretxabaleta, Alfredo L.; Ganju, Neil K.; Butman, Bradford; Signell, Richard P.

2017-04-01

A system of barrier islands and back-barrier bays occurs along southern Long Island, New York, and in many coastal areas worldwide. Characterizing the bay physical response to water level fluctuations is needed to understand flooding during extreme events and evaluate their relation to geomorphological changes. Offshore sea level is one of the main drivers of water level fluctuations in semienclosed back-barrier bays. We analyzed observed water levels (October 2007 to November 2015) and developed analytical models to better understand bay water level along southern Long Island. An increase (˜0.02 m change in 0.17 m amplitude) in the dominant M2 tidal amplitude (containing the largest fraction of the variability) was observed in Great South Bay during mid-2014. The observed changes in both tidal amplitude and bay water level transfer from offshore were related to the dredging of nearby inlets and possibly the changing size of a breach across Fire Island caused by Hurricane Sandy (after December 2012). The bay response was independent of the magnitude of the fluctuations (e.g., storms) at a specific frequency. An analytical model that incorporates bay and inlet dimensions reproduced the observed transfer function in Great South Bay and surrounding areas. The model predicts the transfer function in Moriches and Shinnecock bays where long-term observations were not available. The model is a simplified tool to investigate changes in bay water level and enables the evaluation of future conditions and alternative geomorphological settings.

Observations and a linear model of water level in an interconnected inlet-bay system

USGS Publications Warehouse

Aretxabaleta, Alfredo; Ganju, Neil K.; Butman, Bradford; Signell, Richard

2017-01-01

A system of barrier islands and back-barrier bays occurs along southern Long Island, New York, and in many coastal areas worldwide. Characterizing the bay physical response to water level fluctuations is needed to understand flooding during extreme events and evaluate their relation to geomorphological changes. Offshore sea level is one of the main drivers of water level fluctuations in semienclosed back-barrier bays. We analyzed observed water levels (October 2007 to November 2015) and developed analytical models to better understand bay water level along southern Long Island. An increase (∼0.02 m change in 0.17 m amplitude) in the dominant M2 tidal amplitude (containing the largest fraction of the variability) was observed in Great South Bay during mid-2014. The observed changes in both tidal amplitude and bay water level transfer from offshore were related to the dredging of nearby inlets and possibly the changing size of a breach across Fire Island caused by Hurricane Sandy (after December 2012). The bay response was independent of the magnitude of the fluctuations (e.g., storms) at a specific frequency. An analytical model that incorporates bay and inlet dimensions reproduced the observed transfer function in Great South Bay and surrounding areas. The model predicts the transfer function in Moriches and Shinnecock bays where long-term observations were not available. The model is a simplified tool to investigate changes in bay water level and enables the evaluation of future conditions and alternative geomorphological settings.

Kiel Canal: Past and future threats for shipping resulting from precipitation, wind surge and sea level rise

NASA Astrophysics Data System (ADS)

Ganske, Anette; Hüttl-Kabus, Sabine; Möller, Jens; Schade, Nils; Heinrich, Hartmut; Tinz, Birger

2017-04-01

The Kiel Canal is the most frequented artificial waterway in the world. It connects the North Sea and the Hamburg Harbor with the Baltic Sea and has a length of about 100 km. The Canal receives its water from the upper catchment of the river Eider. Discharge from the Canal towards the North Sea is via the sluices at Brunsbüttel (90%) into river Elbe and into the Baltic Sea via the sluices at Kiel-Holtenau. A risk of closure of the Canal occurs when high precipitation in the catchment meets high water levels in the river Elbe and/or the Baltic preventing the discharge of excess Canal water. Future sea level rise jointly with other effects such as possibly increasing wind surge and precipitation will close the gap between the inner and outer water levels, so that someday the outside levels will surmount the inner one. The German Federal Ministry of Transport and Digital Infrastructure (BMVI) tasked its internal Network of Experts to run a case study on the evolution of critical water levels in order to estimate risks and vulnerabilities for adaptation measures. First step of the investigation is a search for factors or combination of factors responsible for closures in the past. Candidates are factors such as higher water levels at low tides, high precipitation events on land, soil moisture and human factors like preventive water management measures. Second step will be the search for the natural criteria in climate projections. Here we report on the results of the first step of the case study with a focus on the exit towards the North Sea. There, discharge is possible only during low tide. Presently still sufficient difference in height exists between the levels in the Canal and the river Elbe allowing for a free flow of excess Canal water. Shipping is ceased when levels in the Canal surpass safety limits due to high precipitation events in the catchment jointly with high outer water levels. We used atmospheric data from ERA-Interim reanalysis instead of gauge data for reconstructing the history in order to provide metrics that in the second step can be searched in Atmosphere Regional Climate Model runs. Water levels at Brunsbüttel were determined with hourly resolution using atmospheric conditions and astronomical tide. Ocean Model results were and will be excluded because of the small number of runs with astronomical tides and sufficient resolution. Past inflow from the tributary rivers into the Canal was simulated via antecedent and event precipitation derived from the REGNIE data set. Finally, the potential of critical situations in the past was calculated by combining both results and compared their occurrences with the recordings of the responsible waterway authority. In the second step we will analyze the proxies elaborated in step one in regional climate projections and combine them with expected changes of the sea levels in the North and Baltic Seas.

Impact of European Union Legislation On The Wash Catchment, U.k.

NASA Astrophysics Data System (ADS)

Daldorph, P.; Wheater, H.; Saunders, A.

A case study is presented which shows the impact of existing European Legislation (Urban Waste Water Directive, Nitrate Directive, Bathing Waters Directive, Habitats Directive) on aquatic nutrient concentrations in the 16112 km2 catchment area of The Wash in eastern England , including both the inland and coastal zones. Information is provided on the implementation process (administrative and economic) and the observed impacts of measures to reduce environmental nutrient levels. Impacts are compared with simulations of nutrients in the inland and coastal zones, and the modeling tools are further used to predict impacts of future management change, e.g. to meet possible requirements of the Water Framework Directive. The issues in setting future environmental targets and research needs to underpin this process are discussed in the context of developing river basin management plans to support the Common Implementation Strategy for the Water Framework Directive.

An integrated assessment of energy-water nexus at the state level in the United States: Projections and analyses under different scenarios through 2095

NASA Astrophysics Data System (ADS)

Liu, L.; Patel, P. L.; Hejazi, M. I.; Kyle, P.; Davies, E. G.; Zhou, Y.; Clarke, L.; Edmonds, J.

2013-12-01

Water withdrawals for thermoelectric power plants account for approximately half of the total water use in the United States. With growing electricity demands in the future and limited water supplies in many water-scarce states in the U.S., grasping the trade-off between energy and water requires an integrated modeling approach that can capture the interactions among energy, water availability, climate, technology, and economic factors at various scales. In this study, the Global Change Assessment Model (GCAM), a technologically-detailed integrated model of the economy, energy, agriculture and land use, water, and climate systems, with 14 geopolitical regions that are further dissaggregated into up to 18 agro-ecological zones, was extended to model the electricity and water systems at the state level in the U.S. More specifically, GCAM was employed to estimate future state-level electricity generation and demands, and the associated water withdrawals and consumptions under a set of six scenarios with extensive levels of details on generation fuel portfolio, cooling technology mix, and water use intensities. The state-level estimates were compared against available inventories where good agreement was achieved on national and regional levels. We then explored the electric-sector water use up to 2095, focusing on implications from: 1) socioeconomics and growing demands, 2) the adoption of climate mitigation policy (e.g., RCP4.5 W/m2 vs. a reference scenario), 3) the transition of cooling systems, 4) constraints on electricity trading across states (full trading vs. limited trading), and 5) the adoption of water saving technologies. Overall, the fast retirement of once-through cooling, together with the gradual transition from fossil fuels dominant to a mixture of different fuels, accelerate the decline of water withdrawals and correspondingly compensate consumptive water use. Results reveal that U.S. electricity generation expands significantly as population grows, while U.S. electric-sector water withdrawals are projected to decline by 8.6% - 89% by 2095 and water consumptions are projected to increase by 14% - 101%. Some regional patterns could be observed when analyzing the state-level results spatially. Under the climate mitigation policy (RCP4.5) scenario, nuclear power plants contribute heavily to total electric-sector water withdrawal and consumption in Eastern U.S., while under the reference scenario, coal power plants are the primary water users in Eastern U.S. In the reference scenario, Eastern U.S. is projected to experience substantial drops in water withdrawals, while the Western U.S. will likely endure a moderate increase over the century. The highly-resolved nature of this study both geographically and technologically provides a useful platform to address scientific and policy relevant and emerging issues at the heart of the water-energy nexus in the U.S. Although this study is focused on the U.S., it is performed in the context of the global framework of GCAM where local changes can propagate to influence decisions in other regions outside of the U.S. and vice versa.

Simulation of Groundwater Flow in the Coastal Plain Aquifer System of Virginia

USGS Publications Warehouse

Heywood, Charles E.; Pope, Jason P.

2009-01-01

The groundwater model documented in this report simulates the transient evolution of water levels in the aquifers and confining units of the Virginia Coastal Plain and adjacent portions of Maryland and North Carolina since 1890. Groundwater withdrawals have lowered water levels in Virginia Coastal Plain aquifers and have resulted in drawdown in the Potomac aquifer exceeding 200 feet in some areas. The discovery of the Chesapeake Bay impact crater and a revised conceptualization of the Potomac aquifer are two major changes to the hydrogeologic framework that have been incorporated into the groundwater model. The spatial scale of the model was selected on the basis of the primary function of the model of assessing the regional water-level responses of the confined aquifers beneath the Coastal Plain. The local horizontal groundwater flow through the surficial aquifer is not intended to be accurately simulated. Representation of recharge, evapotranspiration, and interaction with surface-water features, such as major rivers, lakes, the Chesapeake Bay, and the Atlantic Ocean, enable simulation of shallow flow-system details that influence locations of recharge to and discharge from the deeper confined flow system. The increased density of groundwater associated with the transition from fresh to salty groundwater near the Atlantic Ocean affects regional groundwater flow and was simulated with the Variable Density Flow Process of SEAWAT (a U.S. Geological Survey program for simulation of three-dimensional variable-density groundwater flow and transport). The groundwater density distribution was generated by a separate 108,000-year simulation of Pleistocene freshwater flushing around the Chesapeake Bay impact crater during transient sea-level changes. Specified-flux boundaries simulate increasing groundwater underflow out of the model domain into Maryland and minor underflow from the Piedmont Province into the model domain. Reported withdrawals accounted for approximately 75 percent of the total groundwater withdrawn from Coastal Plain aquifers during the year 2000. Unreported self-supplied withdrawals were simulated in the groundwater model by specifying their probable locations, magnitudes, and aquifer assignments on the basis of a separate study of domestic-well characteristics in Virginia. The groundwater flow model was calibrated to 7,183 historic water-level observations from 497 observation wells with the parameter-estimation codes UCODE-2005 and PEST. Most water-level observations were from the Potomac aquifer system, which permitted a more complex spatial distribution of simulated hydraulic conductivity within the Potomac aquifer than was possible for other aquifers. Zone, function, and pilot-point approaches were used to distribute assigned hydraulic properties within the aquifer system. The good fit (root mean square error = 3.6 feet) of simulated to observed water levels and reasonableness of the estimated parameter values indicate the model is a good representation of the physical groundwater flow system. The magnitudes and temporal and spatial distributions of residuals indicate no appreciable model bias. The model is intended to be useful for predicting changes in regional groundwater levels in the confined aquifer system in response to future pumping. Because the transient release of water stored in low-permeability confining units is simulated, drawdowns resulting from simulated pumping stresses may change substantially through time before reaching steady state. Consequently, transient simulations of water levels at different future times will be more accurate than a steady-state simulation for evaluating probable future aquifer-system responses to proposed pumping.

Concerns and perceptions immediately following Superstorm Sandy: ratings for property damage were higher than for health issues

PubMed Central

Burger, Joanna; Gochfeld, Michael

2015-01-01

Governmental officials, health and safety professionals, early responders, and the public are interested in the perceptions and concerns of people faced with a crisis, especially during and immediately after a disaster strikes. Reliable information can lead to increased individual and community preparedness for upcoming crises. The objective of this research was to evaluate concerns of coastal and central New Jersey residents within the first 100 days of Superstorm Sandy’s landfall. Respondents living in central New Jersey and Jersey shore communities were differentially impacted by the storm, with shore residents having higher evacuation rates (47% vs. 13%), more flood waters in their homes, longer power outages (average 23 vs. 6 days), and longer periods without Internet (29 vs. 6 days). Ratings of concerns varied both among and within categories as a function of location (central vs. coastal New Jersey), stressor level (ranging from 1 to 3 for combinations of power outages, high winds, and flooding), and demographics. Respondents were most concerned about property damage, health, inconveniences, ecological services, and nuclear power plants in that order. Respondents from the shore gave higher ratings to the concerns within each major category, compared to those from central Jersey. Four findings have implications for understanding future risk, recovery, and resiliency: (1) respondents with the highest stressor level (level 3) were more concerned about water damage than others, (2) respondents with flood damage were more concerned about water drainage and mold than others, (3) respondents with the highest stressor levels rated all ecological services higher than others, and (4) shore respondents rated all ecological services higher than central Jersey residents. These data provide information to design future preparedness plans, improve resiliency for future severe weather events, and reduce public health risk. PMID:27011757

Uncertainty estimation of water levels for the Mitch flood event in Tegucigalpa

NASA Astrophysics Data System (ADS)

Fuentes Andino, D. C.; Halldin, S.; Lundin, L.; Xu, C.

2012-12-01

Hurricane Mitch in 1998 left a devastating flood in Tegucigalpa, the capital city of Honduras. Simulation of elevated water surfaces provides a good way to understand the hydraulic mechanism of large flood events. In this study the one-dimensional HEC-RAS model for steady flow conditions together with the two-dimensional Lisflood-fp model were used to estimate the water level for the Mitch event in the river reaches at Tegucigalpa. Parameters uncertainty of the model was investigated using the generalized likelihood uncertainty estimation (GLUE) framework. Because of the extremely large magnitude of the Mitch flood, no hydrometric measurements were taken during the event. However, post-event indirect measurements of discharge and observed water levels were obtained in previous works by JICA and USGS. To overcome the problem of lacking direct hydrometric measurement data, uncertainty in the discharge was estimated. Both models could well define the value for channel roughness, though more dispersion resulted from the floodplain value. Analysis of the data interaction showed that there was a tradeoff between discharge at the outlet and floodplain roughness for the 1D model. The estimated discharge range at the outlet of the study area encompassed the value indirectly estimated by JICA, however the indirect method used by the USGS overestimated the value. If behavioral parameter sets can well reproduce water surface levels for past events such as Mitch, more reliable predictions for future events can be expected. The results acquired in this research will provide guidelines to deal with the problem of modeling past floods when no direct data was measured during the event, and to predict future large events taking uncertainty into account. The obtained range of the uncertain flood extension will be an outcome useful for decision makers.

Coastal Storm Hazards from Virginia to Maine

DTIC Science & Technology

2015-11-01

study, storm surge, tide, waves, wind, atmospheric pressure, and currents were the dominant storm responses computed. The effect of sea level change on...coastal storm hazards and vulnerability nationally (USACE 2015). NACCS goals also included evaluating the effect of future sea level change (SLC) on...the computed high-fidelity responses included storm surge, astronomical tide, waves, wave effects on water levels, storm duration, wind, currents

Long-term (1930-2010) trends in groundwater levels in Texas: influences of soils, landcover and water use.

PubMed

Chaudhuri, Sriroop; Ale, Srinivasulu

2014-08-15

Rapid groundwater depletion has raised grave concerns about sustainable development in many parts of Texas, as well as in other parts of the world. Previous hydrologic investigations on groundwater levels in Texas were conducted mostly on aquifer-specific basis, and hence lacked state-wide panoramic view. The aim of this study was to present a qualitative overview of long-term (1930-2010) trends in groundwater levels in Texas and identify spatial patterns by applying different statistical (boxplots, correlation-regression, hierarchical cluster analysis) and geospatial techniques (Moran's I, Local Indicators of Spatial Association) on 136,930 groundwater level observations from Texas Water Development Board's database. State-wide decadal median water-levels declined from about 14 m from land surface in the 1930s to about 36 m in the 2000s. Number of counties with deeper median water-levels (water-level depth>100 m) increased from 2 to 13 between 1930s and 2000s, accompanied by a decrease in number of counties having shallower median water-levels (water-level depth<25 m) from 134 to 113. Water-level declines across Texas, however, mostly followed logarithmic trends marked by leveling-off phenomena in recent times. Assessment of water-levels by Groundwater Management Areas (GMA), management units created to address groundwater depletion issues, indicated hotspots of deep water-levels in Texas Panhandle and GMA 8 since the 1960s. Contrasting patterns in water use, landcover, geology and soil properties distinguished Texas Panhandle from GMA 8. Irrigated agriculture is the major cause of depletion in the Texas Panhandle as compared to increasing urbanization in GMA 8. Overall our study indicated that use of robust spatial and statistical methods can reveal important details about the trends in water-level changes and shed lights on the associated factors. Due to very generic nature, techniques used in this study can also be applied to other areas with similar eco-hydrologic issues to identify regions that warrant future management actions. Copyright © 2014 Elsevier B.V. All rights reserved.

Heavy metals in drinking water: Occurrences, implications, and future needs in developing countries.

PubMed

Chowdhury, Shakhawat; Mazumder, M A Jafar; Al-Attas, Omar; Husain, Tahir

2016-11-01

Heavy metals in drinking water pose a threat to human health. Populations are exposed to heavy metals primarily through water consumption, but few heavy metals can bioaccumulate in the human body (e.g., in lipids and the gastrointestinal system) and may induce cancer and other risks. To date, few thousand publications have reported various aspects of heavy metals in drinking water, including the types and quantities of metals in drinking water, their sources, factors affecting their concentrations at exposure points, human exposure, potential risks, and their removal from drinking water. Many developing countries are faced with the challenge of reducing human exposure to heavy metals, mainly due to their limited economic capacities to use advanced technologies for heavy metal removal. This paper aims to review the state of research on heavy metals in drinking water in developing countries; understand their types and variability, sources, exposure, possible health effects, and removal; and analyze the factors contributing to heavy metals in drinking water. This study identifies the current challenges in developing countries, and future research needs to reduce the levels of heavy metals in drinking water. Copyright © 2016 Elsevier B.V. All rights reserved.

The High Plains Aquifer, USA: Groundwater development and sustainability

USGS Publications Warehouse

Dennehy, K.F.; Litke, D.W.; McMahon, P.B.

2002-01-01

The High Plains Aquifer, located in the United States, is one of the largest freshwater aquifers in the world and is threatened by continued decline in water levels and deteriorating water quality. Understanding the physical and cultural features of this area is essential to assessing the factors that affect this groundwater resource. About 27% of the irrigated land in the United States overlies this aquifer, which yields about 30% of the nation's groundwater used for irrigation of crops including wheat, corn, sorghum, cotton and alfalfa. In addition, the aquifer provides drinking water to 82% of the 2.3 million people who live within the aquifer boundary. The High Plains Aquifer has been significantly impacted by human activities. Groundwater withdrawals from the aquifer exceed recharge in many areas, resulting in substantial declines in groundwater level. Residents once believed that the aquifer was an unlimited resource of high-quality water, but they now face the prospect that much of the water may be gone in the near future. Also, agricultural chemicals are affecting the groundwater quality. Increasing concentrations of nitrate and salinity can first impair the use of the water for public supply and then affect its suitability for irrigation. A variety of technical and institutional measures are currently being planned and implemented across the aquifer area in an attempt to sustain this groundwater resource for future generations. However, because groundwater withdrawals remain high and water quality impairments are becoming more commonplace, the sustainability of the High Plains Aquifer is uncertain.

Modeling level change in Lake Urmia using hybrid artificial intelligence approaches

NASA Astrophysics Data System (ADS)

Esbati, M.; Ahmadieh Khanesar, M.; Shahzadi, Ali

2017-06-01

The investigation of water level fluctuations in lakes for protecting them regarding the importance of these water complexes in national and regional scales has found a special place among countries in recent years. The importance of the prediction of water level balance in Lake Urmia is necessary due to several-meter fluctuations in the last decade which help the prevention from possible future losses. For this purpose, in this paper, the performance of adaptive neuro-fuzzy inference system (ANFIS) for predicting the lake water level balance has been studied. In addition, for the training of the adaptive neuro-fuzzy inference system, particle swarm optimization (PSO) and hybrid backpropagation-recursive least square method algorithm have been used. Moreover, a hybrid method based on particle swarm optimization and recursive least square (PSO-RLS) training algorithm for the training of ANFIS structure is introduced. In order to have a more fare comparison, hybrid particle swarm optimization and gradient descent are also applied. The models have been trained, tested, and validated based on lake level data between 1991 and 2014. For performance evaluation, a comparison is made between these methods. Numerical results obtained show that the proposed methods with a reasonable error have a good performance in water level balance prediction. It is also clear that with continuing the current trend, Lake Urmia will experience more drop in the water level balance in the upcoming years.

Scenarios reveal pathways to sustain future ecosystem services in an agricultural landscape.

PubMed

Qiu, Jiangxiao; Carpenter, Stephen R; Booth, Eric G; Motew, Melissa; Zipper, Samuel C; Kucharik, Christopher J; Chen, Xi; Loheide, Steven P; Seifert, Jenny; Turner, Monica G

2018-01-01

Sustaining food production, water quality, soil retention, flood, and climate regulation in agricultural landscapes is a pressing global challenge given accelerating environmental changes. Scenarios are stories about plausible futures, and scenarios can be integrated with biophysical simulation models to explore quantitatively how the future might unfold. However, few studies have incorporated a wide range of drivers (e.g., climate, land-use, management, population, human diet) in spatially explicit, process-based models to investigate spatial-temporal dynamics and relationships of a portfolio of ecosystem services. Here, we simulated nine ecosystem services (three provisioning and six regulating services) at 220 × 220 m from 2010 to 2070 under four contrasting scenarios in the 1,345-km 2 Yahara Watershed (Wisconsin, USA) using Agro-IBIS, a dynamic model of terrestrial ecosystem processes, biogeochemistry, water, and energy balance. We asked (1) How does ecosystem service supply vary among alternative future scenarios? (2) Where on the landscape is the provision of ecosystem services most susceptible to future social-ecological changes? (3) Among alternative future scenarios, are relationships (i.e., trade-offs, synergies) among food production, water, and biogeochemical services consistent over time? Our results showed that food production varied substantially with future land-use choices and management, and its trade-offs with water quality and soil retention persisted under most scenarios. However, pathways to mitigate or even reverse such trade-offs through technological advances and sustainable agricultural practices were apparent. Consistent relationships among regulating services were identified across scenarios (e.g., trade-offs of freshwater supply vs. flood and climate regulation, and synergies among water quality, soil retention, and climate regulation), suggesting opportunities and challenges to sustaining these services. In particular, proactive land-use changes and management may buffer water quality against undesirable future climate changes, but changing climate may overwhelm management efforts to sustain freshwater supply and flood regulation. Spatially, changes in ecosystem services were heterogeneous across the landscape, underscoring the power of local actions and fine-scale management. Our research highlights the value of embracing spatial and temporal perspectives in managing ecosystem services and their complex interactions, and provides a system-level understanding for achieving sustainability of the food-water-climate nexus in agricultural landscapes. © 2017 by the Ecological Society of America.

Physical and virtual water transfers for regional water stress alleviation in China

PubMed Central

Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R.; Guan, Dabo; Hubacek, Klaus

2015-01-01

Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management. PMID:25583516

Physical and virtual water transfers for regional water stress alleviation in China.

PubMed

Zhao, Xu; Liu, Junguo; Liu, Qingying; Tillotson, Martin R; Guan, Dabo; Hubacek, Klaus

2015-01-27

Water can be redistributed through, in physical terms, water transfer projects and virtually, embodied water for the production of traded products. Here, we explore whether such water redistributions can help mitigate water stress in China. This study, for the first time to our knowledge, both compiles a full inventory for physical water transfers at a provincial level and maps virtual water flows between Chinese provinces in 2007 and 2030. Our results show that, at the national level, physical water flows because of the major water transfer projects amounted to 4.5% of national water supply, whereas virtual water flows accounted for 35% (varies between 11% and 65% at the provincial level) in 2007. Furthermore, our analysis shows that both physical and virtual water flows do not play a major role in mitigating water stress in the water-receiving regions but exacerbate water stress for the water-exporting regions of China. Future water stress in the main water-exporting provinces is likely to increase further based on our analysis of the historical trajectory of the major governing socioeconomic and technical factors and the full implementation of policy initiatives relating to water use and economic development. Improving water use efficiency is key to mitigating water stress, but the efficiency gains will be largely offset by the water demand increase caused by continued economic development. We conclude that much greater attention needs to be paid to water demand management rather than the current focus on supply-oriented management.

Radiation field control at the latest BWR plants -- design principle, operational experience and future subjects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Uchida, Shunsuke; Ohsumi, Katsumi; Takashima, Yoshie

1995-03-01

Improvements of operational procedures to control water chemistry, e.g., nickel/iron control, as well as application of hardware improvements for reducing radioactive corrosion products resulted in an extremely low occupational exposure of less than 0.5 man.Sv/yr without any serious impact on the radwaste system, for BWR plants involved in the Japanese Improvement and Standardization Program. Recently, {sup 60}C radioactively in the reactor water has been increasing due to less crud fixation on the two smooth surfaces of new type high performance fuels and to the pH drop caused by chromium oxide anions released from stainless steel structures and pipings. This increasemore » must be limited by changes in water chemistry, e.g., applications of modified nickel/iron ratio control and weak alkali control. Controlled water chemistry to optimize three points, the plant radiation level and integrities of fuel and structural materials, is the primary future subject for BWR water chemistry.« less

Results of the Level-1 Water-Quality Inventory at the Pinnacles National Monument, June 2006

USGS Publications Warehouse

Borchers, James W.; Lyttge, Michael S.

2007-01-01

To help define baseline water quality of key water resources at Pinnacles National Monument, California, the U.S. Geological Survey collected and analyzed ground water from seven springs sampled during June 2006. During the dry season, seeps and springs are the primary source of water for wildlife in the monument and provide habitat for plants, amphibians, and aquatic life. Water samples were analyzed for dissolved concentrations of major ions, trace elements, nutrients, stable isotopes of hydrogen and oxygen, and tritium. In most cases, the concentrations of measured water-quality constituents in spring samples were lower than California threshold standards for drinking water and Federal threshold standards for drinking water and aquatic life. The concentrations of dissolved arsenic in three springs were above the Federal Maximum Contaminant Level for drinking water (10 g/L). Water-quality information for samples collected from the springs will provide a reference point for comparison of samples collected from future monitoring networks and hydrologic studies in the Pinnacles National Monument, and will help National Park Service managers assess relations between water chemistry, geology, and land use.

The Spatial Distributions and Variations of Water Environmental Risk in Yinma River Basin, China.

PubMed

Di, Hui; Liu, Xingpeng; Zhang, Jiquan; Tong, Zhijun; Ji, Meichen

2018-03-15

Water environmental risk is the probability of the occurrence of events caused by human activities or the interaction of human activities and natural processes that will damage a water environment. This study proposed a water environmental risk index (WERI) model to assess the water environmental risk in the Yinma River Basin based on hazards, exposure, vulnerability, and regional management ability indicators in a water environment. The data for each indicator were gathered from 2000, 2005, 2010, and 2015 to assess the spatial and temporal variations in water environmental risk using particle swarm optimization and the analytic hierarchy process (PSO-AHP) method. The results showed that the water environmental risk in the Yinma River Basin decreased from 2000 to 2015. The risk level of the water environment was high in Changchun, while the risk levels in Yitong and Yongji were low. The research methods provide information to support future decision making by the risk managers in the Yinma River Basin, which is in a high-risk water environment. Moreover, water environment managers could reduce the risks by adjusting the indicators that affect water environmental risks.

Coherence between coastal and river flooding along the California coast

USGS Publications Warehouse

Odigie, Kingsley O.; Warrick, Jonathan

2018-01-01

Water levels around river mouths are intrinsically determined by sea level and river discharge. If storm-associated coastal water-level anomalies coincide with extreme river discharge, landscapes near river mouths will be flooded by the hydrodynamic interactions of these two water masses. Unfortunately, the temporal relationships between ocean and river water masses are not well understood. The coherence between extreme river discharge and coastal water levels at six California river mouths across different climatic and geographic regions was examined. Data from river gauges, wave buoys, and tide gauges from 2007 to 2014 were integrated to investigate the relationships between extreme river discharge and coastal water levels near the mouths of the Eel, Russian, San Lorenzo, Ventura, Arroyo Trabuco, and San Diego rivers. Results indicate that mean and extreme coastal water levels during extreme river discharge are significantly higher compared with background conditions. Elevated coastal water levels result from the combination of nontidal residuals (NTRs) and wave setups. Mean and extreme (>99th percentile of observations) NTRs are 3–20 cm and ∼30 cm higher during extreme river discharge conditions, respectively. Mean and extreme wave setups are up to 40 cm and ∼20–90 cm higher during extreme river discharge than typical conditions, respectively. These water-level anomalies were generally greatest for the northern rivers and least for the southern rivers. Time-series comparisons suggest that increases in NTRs are largely coherent with extreme river discharge, owing to the low atmospheric pressure systems associated with storms. The potential flooding risks of the concurrent timing of these water masses are tempered by the mixed, semidiurnal tides of the region that have amplitudes of 2–2.5 m. In summary, flooding hazard assessments for floodplains near California river mouths for current or future conditions with sea-level rise should include the temporal coherence of fluvial and oceanic water levels.

Do we have to take an acceleration of sea level rise into account?

NASA Astrophysics Data System (ADS)

Dillingh, D.; Baart, F.; de Ronde, J.

2012-04-01

In view of preservation of safety against inundation and of the many values and functions of the coastal zone, coastal retreat is no longer acceptable. That is why it was decided to maintain the Dutch coastline on its position in 1990. Later the preservation concept was extended to the Dutch coastal foundation, which is the area that encompasses all dune area's and hard sea defences and reaches seawards until the 20m depth contour line. Present Dutch coastal policy is to grow with sea level by means of sand nourishments. A main issue for the planning of sand nourishments is the rate of sea level rise, because that is the main parameter for the volume of the sand needed. The question is than relevant if we already have to take into account an acceleration of sea level rise. Six stations with long water level records, well spread along the Dutch coast, were analysed. Correction of the measured data was considered necessary for an adaptation of the NAP in 2005 as a consequence of movements of the top of the pleistoceen, on which the NAP bench marks have been founded, and for the 18.6 year (nodal) cycle in the time series of yearly mean sea levels. It has been concluded that along the Dutch coast no significant acceleration of sea level rise could be detected yet. Over the last 120 years sea level rose with an average speed of 19 cm per century relative to NAP (the Dutch ordnance datum). Time series shorter than about 50 years showed less robust estimates of sea level rise. Future sea level rise also needs consideration in view of the estimate of future sand nourishment volumes. Scenario's for sea level rise have been derived for the years 2050 and 2100 relative to 1990 by the KNMI (Dutch Met Office) in 2006 for the Dutch situation. Plausible curves have been drawn from 1990 tangent to the linear regression line in 1990 and forced through the high and low scenario projections for 2050 and 2100. These curves show discrepancies with measurements of the last decade, particularly for the high scenario. Dutch design levels for coastal water defence structures (dikes and dunes) are based on extreme value statistics of long time series of high water levels. These design levels have typically return periods of 2000, 4000 and 10.000 years, depending on the importance of the protected dike ring. The last statistical analysis for the update of the design levels refers to the sea level situation of 1985. According to the Water Act Dutch design levels must be tested periodically (every 6 years). Due to sea level rise and tidal changes the design levels are corrected for the rise of the mean high waters from 1985 until the end of the testing period under consideration. This demands a tailoring approach for different regions or locations instead of a national average as for coastal preservation. Runs with climate models and coupled hydrodynamic models in the framework of the Essence project and the Delta Committee 2008 showed no indication for a change in the statistics of extreme storm surge levels. For the estimation of sea level rise over the last 120 years a linear regression gives the most robust estimate. Showing decadal variability needs more sophisticated models. For the last update of the design levels the elegant Whittaker smoother has been applied. Dutch policy prescribes to account for a future sea level rise of 60 cm per century for the design of new dikes or dike reinforcements and 85 cm per century for the long term (200 years) allocation of space for future reinforcements, in agreement with the KNMI'06 scenario's for sea level rise (central value and upper limit).

Facing Water Scarcity in Jordan: Reuse, Demand Reduction, Energy and Transboundary Approaches to Assure Future Water Supplies

NASA Astrophysics Data System (ADS)

Scott, C. A.; El-Naser, H.; Hagan, R. E.; Hijazi, A.

2001-05-01

Jordan is extremely water-scarce with just 170 cubic meters per capita per year to meet domestic, industrial, agricultural, tourism, and environmental demands for water. Given the natural climatological conditions, demographic pressure, and transboundary nature of water resources, all renewable water resources of suitable quality are being exploited and some non-renewable aquifers are being depleted. The heavy exploitation of water resources has contributed to declines in the level of the Dead Sea. Rapid growth in demand, particularly for higher quality water for domestic, industrial and tourism uses, is significantly increasing pressure on agricultural and environmental uses of water, both of which must continue to adapt to reduced volumes and lower quality water. The agricultural sector has begun to respond by improving irrigation efficiency and increasing the use of recycled water. Total demand for water still exceeds renewable supplies while inadequate treatment of sewage used for irrigation creates potential environmental and health risks and presents agricultural marketing challenges that undermine the competitiveness of exports. The adaptive capability of the natural environment may already be past sustainable limits with groundwater discharge oasis wetlands that have been seriously affected. Development of new water resources is extremely expensive in Jordan with an average investment cost of US\\$ 4-5 per cubic meter. Integrated water resources management (IWRM) that incorporates factors external to the 'water sector' as conventionally defined will help to assure sustainable future water supplies in Jordan. This paper examines four IWRM approaches of relevance to Jordan: water reuse, demand management, energy-water linkages, and transboundary water management. While progress in Jordan has been made, the Ministry of Water and Irrigation continues to be concerned about the acute water scarcity the country faces as well as the need to continue working with concerned stakeholders to assure future water supplies.

The Coffee Sand and Ripley aquifers in Mississippi

USGS Publications Warehouse

Boswell, E.H.

1978-01-01

The Coffee Sand and Ripley aquifers, of Cretaceous age, are in the Selma Group in northern Mississippi. The aquifers contain freshwater in an area of about 4,400 square miles in northern Mississippi. Water produced from the aquifers by public water systems and numerous industries in 1975 averaged about 4 Mgal/d. Regional water-level declines have been very small and the aquifers have a moderate potential for future development. The aquifers are used in some areas where there are no other significant sources of ground water. The most common problems in developing water supplies are low yields to wells and hard water. (Kosco-USGS)

Effects of climate change on hydrology and hydraulics of Qu River Basin, East China.

NASA Astrophysics Data System (ADS)

Gao, C.; Zhu, Q.; Zhao, Z.; Pan, S.; Xu, Y. P.

2015-12-01

The impacts of climate change on regional hydrological extreme events have attracted much attention in recent years. This paper aims to provide a general overview of changes on future runoffs and water levels in the Qu River Basin, upper reaches of Qiantang River, East China by combining future climate scenarios, hydrological model and 1D hydraulic model. The outputs of four GCMs BCC, BNU, CanESM and CSIRO under two scenarios RCP4.5 and RCP8.5 for 2021-2050 are chosen to represent future climate change projections. The LARS-WG statistical downscaling method is used to downscale the coarse GCM outputs and generate 50 years of synthetic precipitation and maximum and minimum temperatures to drive the GR4J hydrological model and the 1D hydraulic model for the baseline period 1971-2000 and the future period 2021-2050. Finally the POT (Peaks Over Threshold) method is applied to analyze the change of extreme events in the study area. The results show that design runoffs and water levels all indicate an increasing trend in the future period for Changshangang River, Jiangshangang River and Qu River at most cases, especially for small return periods(≤20), and for Qu River the increase becomes larger, which suggests that the risk of flooding will probably become greater and appropriate adaptation measures need to be taken.

Life-history responses of insects to water-deficit stress: a case study with the aphid Sitobion avenae.

PubMed

Liu, Deguang; Dai, Peng; Li, Shirong; Ahmed, Syed Suhail; Shang, Zheming; Shi, Xiaoqin

2018-05-29

Drought may become one of the greatest challenges for cereal production under future warming scenarios, and its impact on insect pest outbreaks is still controversial. To address this issue, life-history responses of the English grain aphid, Sitobion avenae (Fabricius), from three areas of different drought levels were compared under three water treatments. Significant differences were identified in developmental time, fecundity and adult weight among S. avenae clones from moist, semiarid and arid areas under all the three water treatments. Semiarid and arid area clones tended to have higher heritability for test life-history traits than moist area clones. We identified significant selection of water-deficit on the developmental time of 1st instar nymphs and adult weight for both semiarid and arid area clones. The impact of intermediate and severe water-stress on S. avenae's fitness was neutral and negative (e.g., decreased fecundity and weight), respectively. Compared with arid-area clones, moist- and semiarid-area clones showed higher extents of adaptation to the water-deficit level of their respective source environment. Adult weight was identified as a good indicator for S. avenae's adaptation potential under different water-stress conditions. After their exposure to intermediate water-deficit stress for only five generations, adult weight and fecundity tended to decrease for moist- and semiarid-area clones, but increase for arid-area clones. It is evident from our study that S. avenae clones from moist, semiarid and arid areas have diverged under different water-deficit stress, and such divergence could have a genetic basis. The impact of drought on S. avenae's fitness showed a water-level dependent pattern. Clones of S. avenae were more likely to become adapted to intermediate water-deficit stress than severe water-deficit stress. After continuous water-deficit stress of only five generations, the adaptation potential of S. avenae tended to decrease for moist and semiarid area clones, but increase for arid area clones. The rapid shift of aphids' life-history traits and adaptation potential under drought could have significant implications for their evolutionary dynamics and outbreak risks in future climate change scenarios.

Modeling wetland plant community response to assess water-level regulation scenarios in the Lake Ontario-St. Lawrence River basin

USGS Publications Warehouse

Hudon, Christiane; Wilcox, Douglas; Ingram, Joel

2006-01-01

The International Joint Commission has recently completed a five-year study (2000-2005) to review the operation of structures controlling the flows and levels of the Lake Ontario - St. Lawrence River system. In addition to addressing the multitude of stakeholder interests, the regulation plan review also considers environmental sustainability and integrity of wetlands and various ecosystem components. The present paper outlines the general approach, scientific methodology and applied management considerations of studies quantifying the relationships between hydrology and wetland plant assemblages (% occurrence, surface area) in Lake Ontario and the Upper and Lower St. Lawrence River. Although similar study designs were used across the study region, different methodologies were required that were specifically adapted to suit the important regional differences between the lake and river systems, range in water-level variations, and confounding factors (geomorphic types, exposure, sediment characteristics, downstream gradient of water quality, origin of water masses in the Lower River). Performance indicators (metrics), such as total area of wetland in meadow marsh vegetation type, that link wetland response to water levels will be used to assess the effects of different regulation plans under current and future (climate change) water-supply scenarios.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bougamont, M.; Christoffersen, P.; Price, S. F.

Ongoing, centennial-scale flow variability within the Ross ice streams of West Antarctica suggests that the present-day positive mass balance in this region may reverse in the future. Here we use a three-dimensional ice sheet model to simulate ice flow in this region over 250 years. The flow responds to changing basal properties, as a subglacial till layer interacts with water transported in an active subglacial hydrological system. We show that a persistent weak bed beneath the tributaries of the dormant Kamb Ice Stream is a source of internal ice flow instability, which reorganizes all ice streams in this region, leadingmore » to a reduced (positive) mass balance within decades and a net loss of ice within two centuries. This hitherto unaccounted for flow variability could raise sea level by 5 mm this century. Furthermore, better constraints on future sea level change from this region will require improved estimates of geothermal heat flux and subglacial water transport.« less

Impacts of Human Induced Nitrogen Deposition on Ecosystem Carbon Sequestration and Water Balance in China

NASA Astrophysics Data System (ADS)

Sheng, M.; Yang, D.; Tang, J.; Lei, H.

2017-12-01

Enhanced plant biomass accumulation in response to elevated atmospheric CO2 concentration could dampen the future rate of increase in CO2 levels and associated climate warming. However, many experiments around the world reported that nitrogen availability could limit the sustainability of the ecosystems' response to elevated CO2. In the recent 20 years, atmospheric nitrogen deposition, primarily from fossil fuel combustion, has increased sharply about 25% in China and meanwhile, China has the highest carbon emission in the world, implying a large opportunity to increase vegetation greenness and ecosystem carbon sequestration. Moreover, the water balance of the ecosystem will also change. However, in the future, the trajectory of increasing nitrogen deposition from fossil fuel use is to be controlled by the government policy that shapes the energy and industrial structure. Therefore, the historical and future trajectories of nitrogen deposition are likely very different, and it is imperative to understand how changes in nitrogen deposition will impact the ecosystem carbon sequestration and water balance in China. We here use the Community Land Model (CLM 4.5) to analyze how the change of nitrogen deposition has influenced and will influence the ecosystem carbon and water cycle in China at a high spatial resolution (0.1 degree). We address the following questions: 1) what is the contribution of the nitrogen deposition on historical vegetation greenness? 2) How does the change of nitrogen deposition affect the carbon sequestration? 3) What is its influence to water balance? And 4) how different will be the influence of the nitrogen deposition on ecosystem carbon and water cycling in the future?

Simulating climate change and socio-economic change impacts on flows and water quality in the Mahanadi River system, India.

PubMed

Jin, Li; Whitehead, Paul G; Rodda, Harvey; Macadam, Ian; Sarkar, Sananda

2018-10-01

Delta systems formed by the deposition of sediments at the mouths of large catchments are vulnerable to sea level rise and other climate change impacts. Deltas often have some of the highest population densities in the world and the Mahanadi Delta in India is one of these, with a population of 39 million. The Mahanadi River is a major river in East Central India and flows through Chattisgarh and Orissa states before discharging into the Bay of Bengal. This study uses an Integrated Catchment Model (INCA) to simulate flow dynamics and water quality (nitrogen and phosphorus) and to analyze the impacts of climate change and socio-economic drivers in the Mahanadi River system. Future flows affected by large population growth, effluent discharge increases and changes in irrigation water demand from changing land uses are assessed under shared socio-economic pathways (SSPs). Model results indicate a significant increase in monsoon flows under the future climates at 2050s (2041-2060) and 2090s (2079-2098) which greatly enhances flood potential. The water availability under low flow conditions will be worsened because of increased water demand from population growth and increased irrigation in the future. Decreased concentrations of nitrogen and phosphorus are expected due to increased flow hence dilution. Socio-economic scenarios have a significant impact on water quality but less impact on the river flow. For example, higher population growth, increased sewage treatment discharges, land use change and enhanced atmospheric deposition would result in the deterioration of water quality, while the upgrade of the sewage treatment works lead to improved water quality. In summary, socio-economic scenarios would change future water quality of the Mahanadi River and alter nutrient fluxes transported into the delta region. This study has serious implications for people's livelihoods in the deltaic area and could impact coastal and Bay of Bengal water ecology. Copyright © 2018 Elsevier B.V. All rights reserved.

Concentrations and possible sources of nitrate in water from the Silurian-Devonian aquifer, Cedar Falls, Iowa

USGS Publications Warehouse

Schaap, Bryan D.

1999-01-01

Nitrogen fertilizer sales in Iowa have been higher in recent years than during the mid- 1970’s. This suggests that nitrate concentrations in water from well 9 may persist at present levels or could increase in future years if fertilizer use increases and if higher nitrate concentrations are directly related to higher nitrogen fertilizer use.

Assessment and management of water resources in Egypt to face drought and water scarcity

NASA Astrophysics Data System (ADS)

Wolters, Wouter; El Guindy, Samia; Salah El Deen, Magdy; Roest, Koen; Smit, Robert; Froebrich, Jochen

2013-04-01

Egypt is one of the countries hardest hit by global and climate change. Challenges include population growth; increased demands for food, water, and energy; as well as changing land use patterns and urbanization. Egypt's part of the Mediterranean is characterized by a very complex hydrological system, as it lacks rainfall (Cairo average 30 mm/year) and it is completely dependent on the Nile river flow. The growth of the Egyptian population and its economy in the near future leads to an increase in the demand for water and the overall water allocation priority basically is: first drinking water, then industry, and whatever is remaining will be available for agriculture and nature. Because the agricultural sector uses more than 80 per cent of available water, the main option available to reduce water scarcity in the priority sectors of the economy is to allocate less to the agriculture sector. Scientifically based advances in facing future drought and water scarcity through innovations increasing yields and food security by measures leading to "more crop per drop" are required. New and modern large- and medium-scale agriculture is being developed in desert areas with participation of the private sector for investments. To prepare the farming community and others elsewhere, for the future situation of water shortages, a paradigm shift is needed. New farming systems under tight water supply conditions are in development to prepare for a future with less water. Egyptian farming systems need a major transition to prevent further marginalization of agriculture, which would also have a major impact on food security. Central to this transition should be the increase of value generated per volume available water, also referred to as "more crop per drop" or "more cash per splash". There is room for the urgently required improvement: the present return on water in agriculture in Egypt is about US 0.25 /m3, where values of over US 1 /m3 are "easily" reached elsewhere. Moreover, innovations on resource efficiency enabling use of rest and by-products of one agricultural activity as an input for another one will be profitable for the food producers and will also be better for the environment. The creative design process to reach the required technological and policy innovations contributes to the developed adaptation strategy to face drought and water scarcity. Results will incorporate some previously un-thought of options. The issues of water scarcity and drought have consequences and implications that can no longer be adequately addressed by any one of the Ministries alone. Many other government departments and agencies must be involved and decisions will have to be made at the highest political level. All policies in Egypt must be conscious of the limitations in water availability, and water policies need to address technological developments as well as the full range of other issues, including: macro-economic factors, economic issues that influence farm-level decisions, development of human capital, governance, and financial risk management.

Browns Ferry Nuclear Plant low-level radwaste storage facility ground-water pathway analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boggs, J.M.

1982-10-01

The proposed low-level radwaste storage facility (LLRWSF) at Browns Ferry Nuclear Plant is underlain by soils having low hydraulic conductivity and high sorptive capacity which greatly reduce the risks associated with a potential contaminant excursion. A conservative ground-water pathway accident analysis using flow and solute transport modeling techniques indicates that without interdiction the concentrations of the five radionuclides of concern (Sr-90, Cs-137, Cs-134, Co-60, and Mn-54) would be well below 10 CFR Part 20 criteria at downgradient receptors. These receptors include a possible future private water well located near the eastern site boundary and Wheeler Reservoir. Routine ground-water monitoring ismore » not recommended at the LLRWSF except in the unlikely event of an accident.« less

Land-use impacts on water resources and protected areas: applications of state-and-transition simulation modeling of future scenarios

USGS Publications Warehouse

Wilson, Tamara; Sleeter, Benjamin M.; Sherba, Jason T.; Dick Cameron,

2015-01-01

Human land use will increasingly contribute to habitat loss and water shortages in California, given future population projections and associated land-use demand. Understanding how land-use change may impact future water use and where existing protected areas may be threatened by land-use conversion will be important if effective, sustainable management approaches are to be implemented. We used a state-and-transition simulation modeling (STSM) framework to simulate spatially-explicit (1 km2) historical (1992-2010) and future (2011-2060) land-use change for 52 California counties within Mediterranean California ecoregions. Historical land use and land cover (LULC) change estimates were derived from the Farmland Mapping and Monitoring Program dataset and attributed with county-level agricultural water-use data from the California Department of Water Resources. Five future alternative land-use scenarios were developed and modeled using the historical land-use change estimates and land-use projections based on the Intergovernmental Panel on Climate Change's Special Report on Emission Scenarios A2 and B1 scenarios. Spatial land-use transition outputs across scenarios were combined to reveal scenario agreement and a land conversion threat index was developed to evaluate vulnerability of existing protected areas to proximal land conversion. By 2060, highest LULC conversion threats were projected to impact nearly 10,500 km2 of land area within 10 km of a protected area boundary and over 18,000 km2 of land area within essential habitat connectivity areas. Agricultural water use declined across all scenarios perpetuating historical drought-related land use from 2008-2010 and trends of annual cropland conversion into perennial woody crops. STSM is useful in analyzing land-use related impacts on water resource use as well as potential threats to existing protected land. Exploring a range of alternative, yet plausible, LULC change impacts will help to better inform resource management and mitigation strategies.

Exploring the Potential for Sustainable Future Bioenergy Production in the Arkansas-White-Red River Basin

NASA Astrophysics Data System (ADS)

Baskaran, L.; Jager, H.; Kreig, J.

2016-12-01

Bioenergy production in the US has been projected to increase in the next few years and this has raised concerns over environmentally sustainable production. Specifically, there are concerns that managing lands to produce bioenergy feedstocks in the Mississippi-Atchafalaya River Basin (MARB) may have impacts over the water quality in the streams draining these lands and hamper with efforts to reduce the size of the Gulf of Mexico's "Dead Zone" (hypoxic waters). However, with appropriate choice of feedstocks and good conservation practices, bioenergy production systems can be environmentally and economically sustainable. We evaluated opportunities for producing 2nd generation cellulosic feedstocks that are economically sustainable and improve water quality in the Arkansas-White-Red (AWR) river basin, which is major part of the MARB. We generated a future bioenergy landscape by downscaling county-scale projections of bioenergy crop production produced by an economic model, POLYSYS, at a market price of $60 per dry ton and a 1% annual yield increase. Our future bioenergy landscape includes perennial grasses (switchgrass and miscanthus), short-rotated woody crops (poplar and willow) and annual crops (high yield sorghum, sorghum stubble, corn stover and wheat straw). Using the Soil and Water Assessment Tool (SWAT) we analyzed changes in water quality and quantity by simulating a baseline scenario with the current landscape (2014 land cover) and a future scenario with the bioenergy landscape. Our results over the AWR indicate decreases in median nutrient and sediment loadings from the baseline scenario. We also explored methods to evaluate if conservation practices (such as reducing fertilizer applications, incorporating filter strips, planting cover crops and moving to a no-till system) can improve water quality, while maintaining biomass yield. We created a series of SWAT simulations with varying levels of conservation practices by crop and present our methods towards identifying future scenarios that may minimize water quality and maximize biomass yields.

Improving the Predictability of Severe Water Levels along the Coasts of Marginal Seas

NASA Astrophysics Data System (ADS)

Ridder, N. N.; de Vries, H.; van den Brink, H.; De Vries, H.

2016-12-01

Extreme water levels can lead to catastrophic consequences with severe societal and economic repercussions. Particularly vulnerable are countries that are largely situated below sea level. To support and optimize forecast models, as well as future adaptation efforts, this study assesses the modeled contribution of storm surges and astronomical tides to total water levels under different air-sea momentum transfer parameterizations in a numerical surge model (WAQUA/DCSMv5) of the North Sea. It particularly focuses on the implications for the representation of extreme and rapidly recurring severe water levels over the past decades based on the example of the Netherlands. For this, WAQUA/DCSMv5, which is currently used to forecast coastal water levels in the Netherlands, is forced with ERA Interim reanalysis data. Model results are obtained from two different methodologies to parameterize air-sea momentum transfer. The first calculates the governing wind stress forcing using a drag coefficient derived from the conventional approach of wind speed dependent Charnock constants. The other uses instantaneous wind stress from the parameterization of the quasi-linear theory applied within the ECMWF wave model which is expected to deliver a more realistic forcing. The performance of both methods is tested by validating the model output with observations, paying particular attention to their ability to reproduce rapidly succeeding high water levels and extreme events. In a second step, the common features of and connections between these events are analyzed. The results of this study will allow recommendations for the improvement of water level forecasts within marginal seas and support decisions by policy makers. Furthermore, they will strengthen the general understanding of severe and extreme water levels as a whole and help to extend the currently limited knowledge about clustering events.

Benefits of economic criteria for water scarcity management under global changes: insights from a large-scale hydroeconomic framework

NASA Astrophysics Data System (ADS)

Neverre, Noémie; Dumas, Patrice; Nassopoulos, Hypatia

2016-04-01

Global changes are expected to exacerbate water scarcity issues in the Mediterranean region in the next decades. In this work, we investigate the impacts of reservoirs operation rules based on an economic criterion. We examine whether can they help reduce the costs of water scarcity, and whether they become more relevant under future climatic and socioeconomic conditions. We develop an original hydroeconomic model able to compare future water supply and demand on a large scale, while representing river basin heterogeneity. On the demand side, we focus on the two main sectors of water use: the irrigation and domestic sectors. Demands are projected in terms of both quantity and economic value. Irrigation requirements are computed for 12 types of crops, at the 0.5° spatial resolution, under future climatic conditions (A1B scenario). The computation of the economic benefits of irrigation water is based on a yield comparison approach between rainfed and irrigated crops. For the domestic sector, we project the combined effects of demographic growth, economic development and water cost evolution on future demands. The economic value of domestic water is defined as the economic surplus. On the supply side, we evaluate the impacts of climate change on water inflows to the reservoirs. Operating rules of the reservoirs are set up using a parameterisation-simulation-optimisation approach. The objective is to maximise water benefits. We introduce prudential parametric rules in order to take into account spatial and temporal trade-offs. The methodology is applied to Algeria at the 2050 horizon. Overall, our results show that the supply-demand imbalance and its costs will increase in most basins under future climatic and socioeconomic conditions. Our results suggest that the benefits of operating rules based on economic criteria are not unequivocally increased with global changes: in some basins the positive impact of economic prioritisation is higher under future conditions, but in other basins it is higher under historical conditions. Global changes may be an incentive to use valuation in operating rules in some basins. In other basins, the benefits of reservoirs management based on economic criteria are less pronounced; in this case, trade-offs could arise between implementing economic based operation policies or not. Given its generic nature and low data requirements, the framework developed could be implemented in other regions concerned with water scarcity and its cost, or extended to a global coverage. Water policies at the country or regional level could be assessed.

Adaptation strategies for water supply management in a drought prone Mediterranean river basin: Application of outranking method.

PubMed

Kumar, Vikas; Del Vasto-Terrientes, Luis; Valls, Aida; Schuhmacher, Marta

2016-01-01

The regional water allocation planning is one of those complex decision problems where holistic approach to water supply management considering different criteria would be valuable. However, multi-criteria decision making with diverse indicators measured on different scales and uncertainty levels is difficult to solve. Objective of this paper is to develop scenarios for the future imbalances in water supply and demand for a water stressed Mediterranean area of Northern Spain (Tarragona) and to test the applicability and suitability of an outranking method ELECTRE-III-H for evaluating sectoral water allocation policies. This study is focused on the use of alternative water supply scenarios to fulfil the demand of water from three major sectors: domestic, industrial and agricultural. A detail scenario planning for regional water demand and supply has been discussed. For each future scenario of climate change, the goal is to obtain a ranking of a set of possible actions with regards to different types of indicators (costs, water stress and environmental impact). The analytical method used is based on outranking models for decision aid with hierarchical structures of criteria and ranking alternatives using partial preorders based on pairwise preference relations. We compare several adaptation measures including alternative water sources (reclaimed water and desalination); inter basin water transfer and sectoral demand management coming from industry, agriculture and domestic sectors and tested the sustainability of management actions for different climate change scenarios. Results have shown use of alternative water resources as the most reliable alternative with medium reclaimed water reuse in industry and agriculture and low to medium use of desalination water in domestic and industrial sectors as the best alternative. The proposed method has several advantages such as the management of heterogeneous scales of measurement without requiring any artificial transformation and the management of uncertainty by means of comparisons at a qualitative level in terms of the decision maker preferences. Copyright © 2015 Elsevier B.V. All rights reserved.

Planning and Design of Water Resources Systems Under Climate Change and Variability

NASA Astrophysics Data System (ADS)

Strzepek, K. M.

2014-12-01

Regional and local water supplies and demands are impacted by global and national systems: climate, economics, population and energy as well as policies: development, energy, and environmental. These drivers can result in complex interactions that require deeper understanding in order to provide actionable information for water planners and stakeholders to develop strategic plans in the face of a changing and growing world. To add more complexity to this issue is the fact that all these drivers are uncertain and the type of uncertainty is not the same. This talk will address approaches to Water Resource Planning at sub-national water regions, national levels and trans-boundary river basins under a non-stationary hydro-climatic future. Additionally the talk will address the design of specific water resource projects such as reservoirs and hydroplants that are being designed now but will operate far in the future when the hydro-climatology will be very different. Examples will be drawn from recent work in Africa, Eastern Europe and Central Asia, and North America and some insights and outstanding questions will be presented.

A Global and Spatially Explicit Assessment of Climate Change Impacts on Crop Production and Consumptive Water Use

PubMed Central

Liu, Junguo; Folberth, Christian; Yang, Hong; Röckström, Johan; Abbaspour, Karim; Zehnder, Alexander J. B.

2013-01-01

Food security and water scarcity have become two major concerns for future human's sustainable development, particularly in the context of climate change. Here we present a comprehensive assessment of climate change impacts on the production and water use of major cereal crops on a global scale with a spatial resolution of 30 arc-minutes for the 2030s (short term) and the 2090s (long term), respectively. Our findings show that impact uncertainties are higher on larger spatial scales (e.g., global and continental) but lower on smaller spatial scales (e.g., national and grid cell). Such patterns allow decision makers and investors to take adaptive measures without being puzzled by a highly uncertain future at the global level. Short-term gains in crop production from climate change are projected for many regions, particularly in African countries, but the gains will mostly vanish and turn to losses in the long run. Irrigation dependence in crop production is projected to increase in general. However, several water poor regions will rely less heavily on irrigation, conducive to alleviating regional water scarcity. The heterogeneity of spatial patterns and the non-linearity of temporal changes of the impacts call for site-specific adaptive measures with perspectives of reducing short- and long-term risks of future food and water security. PMID:23460901

A generic hydroeconomic model to assess future water scarcity

NASA Astrophysics Data System (ADS)

Neverre, Noémie; Dumas, Patrice

2015-04-01

We developed a generic hydroeconomic model able to confront future water supply and demand on a large scale, taking into account man-made reservoirs. The assessment is done at the scale of river basins, using only globally available data; the methodology can thus be generalized. On the supply side, we evaluate the impacts of climate change on water resources. The available quantity of water at each site is computed using the following information: runoff is taken from the outputs of CNRM climate model (Dubois et al., 2010), reservoirs are located using Aquastat, and the sub-basin flow-accumulation area of each reservoir is determined based on a Digital Elevation Model (HYDRO1k). On the demand side, agricultural and domestic demands are projected in terms of both quantity and economic value. For the agricultural sector, globally available data on irrigated areas and crops are combined in order to determine irrigated crops localization. Then, crops irrigation requirements are computed for the different stages of the growing season using Allen (1998) method with Hargreaves potential evapotranspiration. Irrigation water economic value is based on a yield comparison approach between rainfed and irrigated crops. Potential irrigated and rainfed yields are taken from LPJmL (Blondeau et al., 2007), or from FAOSTAT by making simple assumptions on yield ratios. For the domestic sector, we project the combined effects of demographic growth, economic development and water cost evolution on future demands. The method consists in building three-blocks inverse demand functions where volume limits of the blocks evolve with the level of GDP per capita. The value of water along the demand curve is determined from price-elasticity, price and demand data from the literature, using the point-expansion method, and from water costs data. Then projected demands are confronted to future water availability. Operating rules of the reservoirs and water allocation between demands are based on the maximization of water benefits, over time and space. A parameterisation-simulation-optimisation approach is used. This gives a projection of future water scarcity in the different locations and an estimation of the associated direct economic losses from unsatisfied demands. This generic hydroeconomic model can be easily applied to large-scale regions, in particular developing regions where little reliable data is available. We will present an application to Algeria, up to the 2050 horizon.

Mapping groundwater level and aquifer storage variations from InSAR measurements in the Madrid aquifer, Central Spain

NASA Astrophysics Data System (ADS)

Béjar-Pizarro, Marta; Ezquerro, Pablo; Herrera, Gerardo; Tomás, Roberto; Guardiola-Albert, Carolina; Ruiz Hernández, José M.; Fernández Merodo, José A.; Marchamalo, Miguel; Martínez, Rubén

2017-04-01

Groundwater resources are under stress in many regions of the world and the future water supply for many populations, particularly in the driest places on Earth, is threatened. Future climatic conditions and population growth are expected to intensify the problem. Understanding the factors that control groundwater storage variation is crucial to mitigate its adverse consequences. In this work, we apply satellite-based measurements of ground deformation over the Tertiary detritic aquifer of Madrid (TDAM), Central Spain, to infer the spatio-temporal evolution of water levels and estimate groundwater storage variations. Specifically, we use Persistent Scatterer Interferometry (PSI) data during the period 1992-2010 and piezometric time series on 19 well sites covering the period 1997-2010 to build groundwater level maps and quantify groundwater storage variations. Our results reveal that groundwater storage loss occurred in two different periods, 1992-1999 and 2005-2010 and was mainly concentrated in a region of ∼200 km2. The presence of more compressible materials in that region combined with a long continuous water extraction can explain this volumetric deficit. This study illustrates how the combination of PSI and piezometric data can be used to detect small aquifers affected by groundwater storage loss helping to improve their sustainable management.

Assessment of water, sanitation and hygiene interventions in response to an outbreak of typhoid fever in Neno District, Malawi.

PubMed

Bennett, Sarah D; Lowther, Sara A; Chingoli, Felix; Chilima, Benson; Kabuluzi, Storn; Ayers, Tracy L; Warne, Thomas A; Mintz, Eric

2018-01-01

On May 2, 2009 an outbreak of typhoid fever began in rural villages along the Malawi-Mozambique border resulting in 748 illnesses and 44 deaths by September 2010. Despite numerous interventions, including distribution of WaterGuard (WG) for in-home water treatment and education on its use, cases of typhoid fever continued. To inform response activities during the ongoing Typhoid outbreak information on knowledge, attitudes, and practices surrounding typhoid fever, safe water, and hygiene were necessary to plan future outbreak interventions. In September 2010, a survey was administered to female heads in randomly selected households in 17 villages in Neno District, Malawi. Stored household drinking water was tested for free chlorine residual (FCR) levels using the N,N diethyl-p-phenylene diamine colorimetric method (HACH Company, Loveland, CO, USA). Attendance at community-wide educational meetings was reported by 56% of household respondents. Respondents reported that typhoid fever is caused by poor hygiene (77%), drinking unsafe water (49%), and consuming unsafe food (25%), and that treating drinking water can prevent it (68%). WaterGuard, a chlorination solution for drinking water treatment, was observed in 112 (56%) households, among which 34% reported treating drinking water. FCR levels were adequate (FCR ≥ 0.2 mg/L) in 29 (76%) of the 38 households who reported treatment of stored water and had stored water available for testing and an observed bottle of WaterGuard in the home. Soap was observed in 154 (77%) households, among which 51% reported using soap for hand washing. Educational interventions did not reach almost one-half of target households and knowledge remains low. Despite distribution and promotion of WaterGuard and soap during the outbreak response, usage was low. Future interventions should focus on improving water, sanitation and hygiene knowledge, practices, and infrastructure. Typhoid vaccination should be considered.

Assessment of water, sanitation and hygiene interventions in response to an outbreak of typhoid fever in Neno District, Malawi

PubMed Central

Lowther, Sara A.; Chingoli, Felix; Chilima, Benson; Kabuluzi, Storn; Ayers, Tracy L.; Warne, Thomas A.; Mintz, Eric

2018-01-01

On May 2, 2009 an outbreak of typhoid fever began in rural villages along the Malawi-Mozambique border resulting in 748 illnesses and 44 deaths by September 2010. Despite numerous interventions, including distribution of WaterGuard (WG) for in-home water treatment and education on its use, cases of typhoid fever continued. To inform response activities during the ongoing Typhoid outbreak information on knowledge, attitudes, and practices surrounding typhoid fever, safe water, and hygiene were necessary to plan future outbreak interventions. In September 2010, a survey was administered to female heads in randomly selected households in 17 villages in Neno District, Malawi. Stored household drinking water was tested for free chlorine residual (FCR) levels using the N,N diethyl-p-phenylene diamine colorimetric method (HACH Company, Loveland, CO, USA). Attendance at community-wide educational meetings was reported by 56% of household respondents. Respondents reported that typhoid fever is caused by poor hygiene (77%), drinking unsafe water (49%), and consuming unsafe food (25%), and that treating drinking water can prevent it (68%). WaterGuard, a chlorination solution for drinking water treatment, was observed in 112 (56%) households, among which 34% reported treating drinking water. FCR levels were adequate (FCR ≥ 0.2 mg/L) in 29 (76%) of the 38 households who reported treatment of stored water and had stored water available for testing and an observed bottle of WaterGuard in the home. Soap was observed in 154 (77%) households, among which 51% reported using soap for hand washing. Educational interventions did not reach almost one-half of target households and knowledge remains low. Despite distribution and promotion of WaterGuard and soap during the outbreak response, usage was low. Future interventions should focus on improving water, sanitation and hygiene knowledge, practices, and infrastructure. Typhoid vaccination should be considered. PMID:29474394

King Tides and Climate Change

EPA Pesticide Factsheets

The highest predicted high tide of the year at a coastal location can bring unusually high water levels and can cause flooding. Learn about these tides including what they are, when they occur, and what they can mean for the future.

Water supply as a constraint on transmission expansion planning in the Western interconnection

NASA Astrophysics Data System (ADS)

Tidwell, Vincent C.; Bailey, Michael; Zemlick, Katie M.; Moreland, Barbara D.

2016-12-01

Consideration of water supply in transmission expansion planning (TEP) provides a valuable means of managing impacts of thermoelectric generation on limited water resources. Toward this opportunity, thermoelectric water intensity factors and water supply availability (fresh and non-fresh sources) were incorporated into a recent TEP exercise conducted for the electric interconnection in the Western United States. The goal was to inform the placement of new thermoelectric generation so as to minimize issues related to water availability. Although freshwater availability is limited in the West, few instances across five TEP planning scenarios were encountered where water availability impacted the development of new generation. This unexpected result was related to planning decisions that favored the development of low water use generation that was geographically dispersed across the West. These planning decisions were not made because of their favorable influence on thermoelectric water demand; rather, on the basis of assumed future fuel and technology costs, policy drivers and the topology of electricity demand. Results also projected that interconnection-wide thermoelectric water consumption would increase by 31% under the business-as-usual case, while consumption would decrease by 42% under a scenario assuming a low-carbon future. Except in a few instances, new thermoelectric water consumption could be accommodated with less than 10% of the local available water supply; however, limited freshwater supplies and state-level policies could increase use of non-fresh water sources for new thermoelectric generation. Results could have been considerably different if scenarios favoring higher-intensity water use generation technology or potential impacts of climate change had been explored. Conduct of this exercise highlighted the importance of integrating water into all phases of TEP, particularly joint management of decisions that are both directly (e.g., water availability constraint) and indirectly (technology or policy constraints) related to future thermoelectric water demand, as well as, the careful selection of scenarios that adequately bound the potential dimensions of water impact.

Water supply as a constraint on transmission expansion planning in the Western interconnection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tidwell, Vincent C.; Bailey, Michael; Zemlick, Katie M.

Here, consideration of water supply in transmission expansion planning (TEP) provides a valuable means of managing impacts of thermoelectric generation on limited water resources. Toward this opportunity, thermoelectric water intensity factors and water supply availability (fresh and non-fresh sources) were incorporated into a recent TEP exercise conducted for the electric interconnection in the Western United States. The goal was to inform the placement of new thermoelectric generation so as to minimize issues related to water availability. Although freshwater availability is limited in the West, few instances across five TEP planning scenarios were encountered where water availability impacted the development ofmore » new generation. This unexpected result was related to planning decisions that favored the development of low water use generation that was geographically dispersed across the West. These planning decisions were not made because of their favorable influence on thermoelectric water demand; rather, on the basis of assumed future fuel and technology costs, policy drivers and the topology of electricity demand. Results also projected that interconnection-wide thermoelectric water consumption would increase by 31% under the business-as-usual case, while consumption would decrease by 42% under a scenario assuming a low-carbon future. Except in a few instances, new thermoelectric water consumption could be accommodated with less than 10% of the local available water supply; however, limited freshwater supplies and state-level policies could increase use of non-fresh water sources for new thermoelectric generation. Results could have been considerably different if scenarios favoring higher-intensity water use generation technology or potential impacts of climate change had been explored. Conduct of this exercise highlighted the importance of integrating water into all phases of TEP, particularly joint management of decisions that are both directly (e.g., water availability constraint) and indirectly (technology or policy constraints) related to future thermoelectric water demand, as well as, the careful selection of scenarios that adequately bound the potential dimensions of water impact.« less

Water supply as a constraint on transmission expansion planning in the Western interconnection

DOE PAGES

Tidwell, Vincent C.; Bailey, Michael; Zemlick, Katie M.; ...

2016-11-21

Here, consideration of water supply in transmission expansion planning (TEP) provides a valuable means of managing impacts of thermoelectric generation on limited water resources. Toward this opportunity, thermoelectric water intensity factors and water supply availability (fresh and non-fresh sources) were incorporated into a recent TEP exercise conducted for the electric interconnection in the Western United States. The goal was to inform the placement of new thermoelectric generation so as to minimize issues related to water availability. Although freshwater availability is limited in the West, few instances across five TEP planning scenarios were encountered where water availability impacted the development ofmore » new generation. This unexpected result was related to planning decisions that favored the development of low water use generation that was geographically dispersed across the West. These planning decisions were not made because of their favorable influence on thermoelectric water demand; rather, on the basis of assumed future fuel and technology costs, policy drivers and the topology of electricity demand. Results also projected that interconnection-wide thermoelectric water consumption would increase by 31% under the business-as-usual case, while consumption would decrease by 42% under a scenario assuming a low-carbon future. Except in a few instances, new thermoelectric water consumption could be accommodated with less than 10% of the local available water supply; however, limited freshwater supplies and state-level policies could increase use of non-fresh water sources for new thermoelectric generation. Results could have been considerably different if scenarios favoring higher-intensity water use generation technology or potential impacts of climate change had been explored. Conduct of this exercise highlighted the importance of integrating water into all phases of TEP, particularly joint management of decisions that are both directly (e.g., water availability constraint) and indirectly (technology or policy constraints) related to future thermoelectric water demand, as well as, the careful selection of scenarios that adequately bound the potential dimensions of water impact.« less

Greenland ice-sheet contribution to sea-level rise buffered by meltwater storage in firn.

PubMed

Harper, J; Humphrey, N; Pfeffer, W T; Brown, J; Fettweis, X

2012-11-08

Surface melt on the Greenland ice sheet has shown increasing trends in areal extent and duration since the beginning of the satellite era. Records for melt were broken in 2005, 2007, 2010 and 2012. Much of the increased surface melt is occurring in the percolation zone, a region of the accumulation area that is perennially covered by snow and firn (partly compacted snow). The fate of melt water in the percolation zone is poorly constrained: some may travel away from its point of origin and eventually influence the ice sheet's flow dynamics and mass balance and the global sea level, whereas some may simply infiltrate into cold snow or firn and refreeze with none of these effects. Here we quantify the existing water storage capacity of the percolation zone of the Greenland ice sheet and show the potential for hundreds of gigatonnes of meltwater storage. We collected in situ observations of firn structure and meltwater retention along a roughly 85-kilometre-long transect of the melting accumulation area. Our data show that repeated infiltration events in which melt water penetrates deeply (more than 10 metres) eventually fill all pore space with water. As future surface melt intensifies under Arctic warming, a fraction of melt water that would otherwise contribute to sea-level rise will fill existing pore space of the percolation zone. We estimate the lower and upper bounds of this storage sink to be 322 ± 44 gigatonnes and  1,289(+388)(-252) gigatonnes, respectively. Furthermore, we find that decades are required to fill this pore space under a range of plausible future climate conditions. Hence, routing of surface melt water into filling the pore space of the firn column will delay expansion of the area contributing to sea-level rise, although once the pore space is filled it cannot quickly be regenerated.

Representation of physiological drought at ecosystem level based on model and eddy covariance measurements

NASA Astrophysics Data System (ADS)

Zhang, Y.; Novick, K. A.; Song, C.; Zhang, Q.; Hwang, T.

2017-12-01

Drought and heat waves are expected to increase both in frequency and amplitude, exhibiting a major disturbance to global carbon and water cycles under future climate change. However, how these climate anomalies translate into physiological drought, or ecosystem moisture stress are still not clear, especially under the co-limitations from soil moisture supply and atmospheric demand for water. In this study, we characterized the ecosystem-level moisture stress in a deciduous forest in the southeastern United States using the Coupled Carbon and Water (CCW) model and in-situ eddy covariance measurements. Physiologically, vapor pressure deficit (VPD) as an atmospheric water demand indicator largely controls the openness of leaf stomata, and regulates atmospheric carbon and water exchanges during periods of hydrological stress. Here, we tested three forms of VPD-related moisture scalars, i.e. exponent (K2), hyperbola (K3), and logarithm (K4) to quantify the sensitivity of light-use efficiency to VPD along different soil moisture conditions. The sensitivity indicators of K values were calibrated based on the framework of CCW using Monte Carlo simulations on the hourly scale, in which VPD and soil water content (SWC) are largely decoupled and the full carbon and water exchanging information are held. We found that three K values show similar performances in the predictions of ecosystem-level photosynthesis and transpiration after calibration. However, all K values show consistent gradient changes along SWC, indicating that this deciduous forest is less responsive to VPD as soil moisture decreases, a phenomena of isohydricity in which plants tend to close stomata to keep the leaf water potential constant and reduce the risk of hydraulic failure. Our study suggests that accounting for such isohydric information, or spectrum of moisture stress along different soil moisture conditions in models can significantly improve our ability to predict ecosystem responses to future drought.

Hydrologic data and description of a hydrologic monitoring plan for the Borax Lake area, Oregon

USGS Publications Warehouse

Schneider, Tiffany Rae; McFarland, William D.

1995-01-01

Information from field visits was used to develop a monitoring plan. The plan would include monitoring Borax Lake by measuring discharge, stage, evaporation, temperature, and specific conductance; water-quality sampling and analysis; and monitoring shallow ground-water levels near Borax Lake using shallow piezometers. Minimally, one hot spring in North Borax Lake Spring Group 1 would be monitored for temperature and specific conductance and sampled for water-quality analysis. In addition, two flowing wells would be monitored for water levels, temperature, specific conductance, and discharge and sampled for water-quality analysis. The construction characteristics of these wells must be verified before long-term data collection begins. In the future, it may be helpful to monitor shallow and (or) deep observation wells drilled into the thermal aquifer to understand the possible effects of geothermal development on Borax Lake and nearby springs.

Evaluation of groundwater levels in the South Platte River alluvial aquifer, Colorado, 1953-2012, and design of initial well networks for monitoring groundwater levels

USGS Publications Warehouse

Wellman, Tristan

2015-01-01

A network of candidate monitoring wells was proposed to initiate a regional monitoring program. Consistent monitoring and analysis of groundwater levels will be needed for informed decisions to optimize beneficial use of water and to limit high groundwater levels in susceptible areas. Finalization of the network will require future field reconnaissance to assess local site conditions and discussions with State authorities.

Adapting water treatment design and operations to the impacts of global climate change

NASA Astrophysics Data System (ADS)

Clark, Robert M.; Li, Zhiwei; Buchberger, Steven G.

2011-12-01

It is anticipated that global climate change will adversely impact source water quality in many areas of the United States and will therefore, potentially, impact the design and operation of current and future water treatment systems. The USEPA has initiated an effort called the Water Resources Adaptation Program (WRAP) which is intended to develop tools and techniques that can assess the impact of global climate change on urban drinking water and wastewater infrastructure. A three step approach for assessing climate change impacts on water treatment operation and design is being persude in this effort. The first step is the stochastic characterization of source water quality, the second step is the application of the USEPA Water Treatment Plant model and the third step is the application of cost algorithms to provide a metric that can be used to assess the coat impact of climate change. A model has been validated using data collected from Cincinnati's Richard Miller Water Treatment Plant for the USEPA Information Collection Rule (ICR) database. An analysis of the water treatment processes in response to assumed perturbations in raw water quality identified TOC, pH, and bromide as the three most important parameters affecting performance of the Miller WTP. The Miller Plant was simulated using the EPA WTP model to examine the impact of these parameters on selected regulated water quality parameters. Uncertainty in influent water quality was analyzed to estimate the risk of violating drinking water maximum contaminant levels (MCLs).Water quality changes in the Ohio River were projected for 2050 using Monte Carlo simulation and the WTP model was used to evaluate the effects of water quality changes on design and operation. Results indicate that the existing Miller WTP might not meet Safe Drinking Water Act MCL requirements for certain extreme future conditions. However, it was found that the risk of MCL violations under future conditions could be controlled by enhancing existing WTP design and operation or by process retrofitting and modification.

LONG-TERM GLOBAL WATER USE PROJECTIONS USING SIX SOCIOECONOMIC SCENARIOS IN AN INTEGRATED ASSESSMENT MODELING FRAMEWORK

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hejazi, Mohamad I.; Edmonds, James A.; Clarke, Leon E.

2014-01-19

In this paper, we assess future water demands for the agricultural (irrigation and livestock), energy (electricity generation, primary energy production and processing), industrial (manufacturing and mining), and municipal sectors, by incorporating water demands into a technologically-detailed global integrated assessment model of energy, agriculture, and climate change – the Global Change Assessment Model (GCAM). Base-year water demands—both gross withdrawals and net consumptive use—are assigned to specific modeled activities in a way that maximizes consistency between bottom-up estimates of water demand intensities of specific technologies and practices, and top-down regional and sectoral estimates of water use. The energy, industrial, and municipal sectorsmore » are represented in fourteen geopolitical regions, with the agricultural sector further disaggregated into as many as eighteen agro-ecological zones (AEZs) within each region. We assess future water demands representing six socioeconomic scenarios, with no constraints imposed by future water supplies. The scenarios observe increases in global water withdrawals from 3,578 km3 year-1 in 2005 to 5,987 – 8,374 km3 year-1 in 2050, and to 4,719 – 12,290 km3 year-1 in 2095. Comparing the projected total regional water withdrawals to the historical supply of renewable freshwater, the Middle East exhibits the highest levels of water scarcity throughout the century, followed by India; water scarcity increases over time in both of these regions. In contrast, water scarcity improves in some regions with large base-year electric sector withdrawals, such as the USA and Canada, due to capital stock turnover and the almost complete phase-out of once-through flow cooling systems. The scenarios indicate that: 1) water is likely a limiting factor in climate change mitigation policies, 2) many regions can be expected to increase reliance on non-renewable groundwater, water reuse, and desalinated water, but they also highlight an important role for development and deployment of water conservation technologies and practices.« less

An Index-Based Assessment of Agricultural Water Scarcity for Sustainable Water Resource Management

NASA Astrophysics Data System (ADS)

Kim, S. E.; Lee, D. K.; Kim, K. S.; Hyun, S.; Kim, Y.

2017-12-01

Global precipitation pattern is changing due to climate change, causing drought and water scarcity all around the world. As water is mandatory to all lives, water availability is becoming essential and so is sustainable water resource management. Especially in agriculture, water resource management is crucial, as it is directly connected to the production. However, many studies about water scarcity show limits by focusing on current situation and overlooking future possibilities of water availability. Also, most of the studies about water scarcity use single index or model. To overcome these shortcomings, we assessed agricultural water scarcity considering future climate, using water scarcity indices. We assessed present and future water scarcity using several indices and compared the results derived from each index. The study area of this research is South Korea, as drought is a prominent problem in agricultural sector. Precipitation in Korea is concentrated in summer, causing severe drought in spring and fall. Rainfall density in Korea is increasing with climate change, and sustainable water resource management is inevitable. In this research, we used irrigational demand along with current and future crop production of 2030 and 2050 as water demand. We projected the future (2020-2100) runoff of dams located in Korea as water demand under future scenarios, RCP 4.5 and 8.5. The result showed severe water scarcity in Southern area of Korea both in the present and the future. It was due to increase of water demand and decrease of precipitation. It indicates that the water scarcity gets more intense in the future, and emphasizes the importance of water resource management of the southern part. This research will be valuable in establishing water resource management in agricultural sector for sustainable water availability in the future.

The relative contribution of waves, tides, and nontidal residuals to extreme total water levels on U.S. West Coast sandy beaches

USGS Publications Warehouse

Serafin, Katherine A.; Ruggiero, Peter; Stockdon, Hilary F.

2017-01-01

To better understand how individual processes combine to cause flooding and erosion events, we investigate the relative contribution of tides, waves, and nontidal residuals to extreme total water levels (TWLs) at the shoreline of U.S. West Coast sandy beaches. Extreme TWLs, defined as the observed annual maximum event and the simulated 100 year return level event, peak in Washington, and are on average larger in Washington and Oregon than in California. The relative contribution of wave-induced and still water levels (SWL) to the 100 year TWL event is similar to that of the annual maximum event; however, the contribution of storm surge to the SWL doubles across events. Understanding the regional variability of TWLs will lead to a better understanding of how sea level rise, changes in storminess, and possible changes in the frequency of major El Niños may impact future coastal flooding and erosion along the U.S. West Coast and elsewhere.

Identification and assessment of hazardous compounds in drinking water.

PubMed

Fawell, J K; Fielding, M

1985-12-01

The identification of organic chemicals in drinking water and their assessment in terms of potential hazardous effects are two very different but closely associated tasks. In relation to both continuous low-level background contamination and specific, often high-level, contamination due to pollution incidents, the identification of contaminants is a pre-requisite to evaluation of significant hazards. Even in the case of the rapidly developing short-term bio-assays which are applied to water to indicate a potential genotoxic hazard (for example Ames tests), identification of the active chemicals is becoming a major factor in the further assessment of the response. Techniques for the identification of low concentrations of organic chemicals in drinking water have developed remarkably since the early 1970s and methods based upon gas chromatography-mass spectrometry (GC-MS) have revolutionised qualitative analysis of water. Such techniques are limited to "volatile" chemicals and these usually constitute a small fraction of the total organic material in water. However, in recent years there have been promising developments in techniques for "non-volatile" chemicals in water. Such techniques include combined high-performance liquid chromatography-mass spectrometry (HPLC-MS) and a variety of MS methods, involving, for example, field desorption, fast atom bombardment and thermospray ionisation techniques. In the paper identification techniques in general are reviewed and likely future developments outlined. The assessment of hazards associated with chemicals identified in drinking and related waters usually centres upon toxicology - an applied science which involves numerous disciplines. The paper examines the toxicological information needed, the quality and deployment of such information and discusses future research needs. Application of short-term bio-assays to drinking water is a developing area and one which is closely involved with, and to some extent dependent on, powerful methods of identification. Recent developments are discussed.

Emerging risks from ballast water treatment: the run-up to the International Ballast Water Management Convention.

PubMed

Werschkun, Barbara; Banerji, Sangeeta; Basurko, Oihane C; David, Matej; Fuhr, Frank; Gollasch, Stephan; Grummt, Tamara; Haarich, Michael; Jha, Awadhesh N; Kacan, Stefan; Kehrer, Anja; Linders, Jan; Mesbahi, Ehsan; Pughiuc, Dandu; Richardson, Susan D; Schwarz-Schulz, Beatrice; Shah, Amisha; Theobald, Norbert; von Gunten, Urs; Wieck, Stefanie; Höfer, Thomas

2014-10-01

Uptake and discharge of ballast water by ocean-going ships contribute to the worldwide spread of aquatic invasive species, with negative impacts on the environment, economies, and public health. The International Ballast Water Management Convention aims at a global answer. The agreed standards for ballast water discharge will require ballast water treatment. Systems based on various physical and/or chemical methods were developed for on-board installation and approved by the International Maritime Organization. Most common are combinations of high-performance filters with oxidizing chemicals or UV radiation. A well-known problem of oxidative water treatment is the formation of disinfection by-products, many of which show genotoxicity, carcinogenicity, or other long-term toxicity. In natural biota, genetic damages can affect reproductive success and ultimately impact biodiversity. The future exposure towards chemicals from ballast water treatment can only be estimated, based on land-based testing of treatment systems, mathematical models, and exposure scenarios. Systematic studies on the chemistry of oxidants in seawater are lacking, as are data about the background levels of disinfection by-products in the oceans and strategies for monitoring future developments. The international approval procedure of ballast water treatment systems compares the estimated exposure levels of individual substances with their experimental toxicity. While well established in many substance regulations, this approach is also criticised for its simplification, which may disregard critical aspects such as multiple exposures and long-term sub-lethal effects. Moreover, a truly holistic sustainability assessment would need to take into account factors beyond chemical hazards, e.g. energy consumption, air pollution or waste generation. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Managing Water-Food-Energy Futures in the Canadian Prairies

NASA Astrophysics Data System (ADS)

Wheater, H. S.; Hassanzadeh, E.; Nazemi, A.; Elshorbagy, A. A.

2016-12-01

The water-food-energy nexus is a convenient phrase to highlight competing societal uses for water and the need for cross-sectoral policy integration, but this can lead to oversimplification of the multiple dimensions of water (and energy) management. In practice, water managers must balance (and prioritize) demands for water for many uses, including environmental flows, and reservoir operation often involves managing conflicting demands, for example to maximize retention for supply, reduce storage to facilitate flood control, and constrain water levels and releases for habitat protection. Agriculture and water quality are also inextricably linked: irrigated agriculture requires appropriate water quality for product quality and certification, but agriculture can be a major source of nutrient pollution, with impacts on human and ecosystem health, drinking water treatment and amenity. And energy-water interactions include energy production (hydropower and cooling water for thermal power generation) and energy consumption (e.g. for pumping and water and wastewater treatment). These dependencies are illustrated for the Canadian prairies, and a risk-based approach to the management of climate change is presented. Trade-offs between economic benefits of hydropower and irrigation are illustrated for alternative climate futures, including implications for freshwater habitats. The results illustrate that inter-sector interactions vary as a function of climate and its variability, and that there is a need for policy to manage inter-sector allocations as a function of economic risk.

Tree water dynamics in a drying and warming world: Future tree water dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grossiord, Charlotte; Sevanto, Sanna; Borrego, Isaac

Disentangling the relative impacts of precipitation reduction and vapour pressure deficit (VPD) on plant water dynamics and determining whether acclimation may influence these patterns in the future is an important challenge. Here, we report sap flux density (FD), stomatal conductance (Gs), hydraulic conductivity (KL) and xylem anatomy in piñon pine (Pinus edulis) and juniper (Juniperus monosperma) trees subjected to five years of precipitation reduction, atmospheric warming (elevated VPD) and their combined effects. No acclimation occurred under precipitation reduction: lower Gs and FD were found for both species compared to ambient conditions. Warming reduced the sensibility of stomata to VPD formore » both species but resulted in the maintenance of Gs and FD to ambient levels only for piñon. For juniper, reduced soil moisture under warming negated benefits of stomatal adjustments and resulted in reduced FD, Gs and KL. Although reduced stomatal sensitivity to VPD also occurred under combined stresses, reductions in Gs, FD and KL took place to similar levels as under single stresses for both species. Our results show that stomatal conductance adjustments to high VPD could minimize but not entirely prevent additive effects of warming and drying on water use and carbon acquisition of trees in semi-arid regions.« less

Transboundary impacts on regional ground water modeling in Texas

USGS Publications Warehouse

Rainwater, K.; Stovall, J.; Frailey, S.; Urban, L.

2005-01-01

Recent legislation required regional grassroots water resources planning across the entire state of Texas. The Texas Water Development Board (TWDB), the state's primary water resource planning agency, divided the state into 16 planning regions. Each planning group developed plans to manage both ground water and surface water sources and to meet future demands of various combinations of domestic, agricultural, municipal, and industrial water consumers. This presentation describes the challenges in developing a ground water model for the Llano Estacado Regional Water Planning Group (LERWPG), whose region includes 21 counties in the Southern High Plains of Texas. While surface water is supplied to several cities in this region, the vast majority of the regional water use comes from the High Plains aquifer system, often locally referred to as the Ogallala Aquifer. Over 95% of the ground water demand is for irrigated agriculture. The LERWPG had to predict the impact of future TWDB-projected water demands, as provided by the TWDB, on the aquifer for the period 2000 to 2050. If detrimental impacts were noted, alternative management strategies must be proposed. While much effort was spent on evaluating the current status of the ground water reserves, an appropriate numerical model of the aquifer system was necessary to demonstrate future impacts of the predicted withdrawals as well as the effects of the alternative strategies. The modeling effort was completed in the summer of 2000. This presentation concentrates on the political, scientific, and nontechnical issues in this planning process that complicated the modeling effort. Uncertainties in data, most significantly in distribution and intensity of recharge and withdrawals, significantly impacted the calibration and predictive modeling efforts. Four predictive scenarios, including baseline projections, recurrence of the drought of record, precipitation enhancement, and reduced irrigation demand, were simulated to identify counties at risk of low final ground water storage volume or low levels of satisfied demand by 2050. Copyright ?? 2005 National Ground Water Association.

Stable isotope ratios of tap water in the contiguous United States

NASA Astrophysics Data System (ADS)

Bowen, Gabriel J.; Ehleringer, James R.; Chesson, Lesley A.; Stange, Erik; Cerling, Thure E.

2007-03-01

Understanding links between water consumers and climatological (precipitation) sources is essential for developing strategies to ensure the long-term sustainability of water supplies. In pursing this understanding a need exists for tools to study and monitor complex human-hydrological systems that involve high levels of spatial connectivity and supply problems that are regional, rather than local, in nature. Here we report the first national-level survey of stable isotope ratios in tap water, including spatially and temporally explicit samples from a large number of cities and towns across the contiguous United States. We show that intra-annual ranges of tap water isotope ratios are relatively small (e.g., <10‰ for δ2H) at most sites. In contrast, spatial variation in tap water isotope ratios is very large, spanning ranges of 163‰ for δ2H and 23.6‰ for δ18O. The spatial distribution of tap water isotope ratios at the national level is similar to that of stable isotope ratios of precipitation. At the regional level, however, pervasive differences between tap water and precipitation isotope ratios can be attributed to hydrological factors in the water source to consumer chain. These patterns highlight the potential for monitoring of tap water isotope ratios to contribute to the study of regional water supply stability and provide warning signals for impending water resource changes. We present the first published maps of predicted tap water isotope ratios for the contiguous United States, which will be useful in guiding future research on human-hydrological systems and as a tool for applied forensics and traceability studies.

Spatial and Temporal Self-Calibration of a Hydroeconomic Model

NASA Astrophysics Data System (ADS)

Howitt, R. E.; Hansen, K. M.

2008-12-01

Hydroeconomic modeling of water systems where risk and reliability of water supply are of critical importance must address explicitly how to model water supply uncertainty. When large fluctuations in annual precipitation and significant variation in flows by location are present, a model which solves with perfect foresight of future water conditions may be inappropriate for some policy and research questions. We construct a simulation-optimization model with limited foresight of future water conditions using positive mathematical programming and self-calibration techniques. This limited foresight netflow (LFN) model signals the value of storing water for future use and reflects a more accurate economic value of water at key locations, given that future water conditions are unknown. Failure to explicitly model this uncertainty could lead to undervaluation of storage infrastructure and contractual mechanisms for managing water supply risk. A model based on sequentially updated information is more realistic, since water managers make annual storage decisions without knowledge of yet to be realized future water conditions. The LFN model runs historical hydrological conditions through the current configuration of the California water system to determine the economically efficient allocation of water under current economic conditions and infrastructure. The model utilizes current urban and agricultural demands, storage and conveyance infrastructure, and the state's hydrological history to indicate the scarcity value of water at key locations within the state. Further, the temporal calibration penalty functions vary by year type, reflecting agricultural water users' ability to alter cropping patterns in response to water conditions. The model employs techniques from positive mathematical programming (Howitt, 1995; Howitt, 1998; Cai and Wang, 2006) to generate penalty functions that are applied to deviations from observed data. The functions are applied to monthly flows across key nodes on the network and to annual carryover storage at ground and surface water storage facilities. To our knowledge, this is the first hydroeconomic model to perform spatial and temporal calibration simultaneously. The base for the LFN model is CALVIN, a hydroeconomic optimization model of the California water system developed at the University of California, Davis (Draper, et al. 2003). The LFN model, programmed in GAMS, is nonlinear, which permits incorporation of dynamic groundwater pumping costs that reflect head elevation. Hydropower production, also nonlinear in storage levels, could be added in the future. In this paper, we describe model implementation and performance over a sequence of water years drawn from the historical hydrologic record in California. Preliminary findings indicate that calibration occurs within acceptable limits and simulations replicate base case results well. Cai, X., and Wang, D. 2006. "Calibrating Holistic Water Resources-Economic Models." Journal of Water Resources Planning and Management November-December. Draper, A.J., M.W. Jenkins, K.W. Kirby, J.R. Lund, and R.E. Howitt. 2003. "Economic-Engineering Optimization for California Water Management." Journal of Water Resources Planning and Management 129(3):155-164. Howitt, R.E. 1995. "Positive Mathematical Programming." American Journal of Agricultural Economics 77:329-342. Howitt, R.E. 1998. "Self-Calibrating Network Flow Models." Working Paper, Department of Agricultural and Resource Economics, University of California, Davis. October 1998. class="ab'>

Water data in US: a spatial, temporal and sectoral analysis

NASA Astrophysics Data System (ADS)

Josset, L.; Allaire, M.; Rising, J. A.; Thomas, C.; Lall, U.

2017-12-01

Water data plays a crucial role in the development and implementation of sustainable water management strategies. Both effective design and assessment hinge on accurate information. This requires environmental, climatic, hydrologic, hydrogeologic, industrial, agricultural, energetic and socio-economic data to accurately characterize and project future supply and demand. In 2001, Vorosmarty et al. painted a stark future for water data, which was qualified as ``a new endangered species". Sixteen years after this publication, we propose a review of the current state of water data in the United States. While considerable progress has been made in data science and model development in the recent years, models are only as good as the data that populate them. After a brief overview of water data aggregated at the national level, we compare datasets from federal agencies with water information collected by individual states. We note in particular the potential gaps in the collected information that would support research beyond water balance accounts to informing regulations, investments, and economic decisions. In addition, we assess the information structures that host and disseminate data as well as data availability and usability (i.e. whether tools are proposed such as metrics, visualization, projections). We conclude our paper with a review of the current technological developments, policies and initiatives that may be transformative and redefine the future of water data. We follow two angles: the progress made in data collection (e.g. remote sensing, datascience, reporting policies) and in data dissemination (frameworks, cyber-infrastructures and standards). We review in particular the current initiatives taking place in US and around the world that promote water data freely available to all.

Deep-convection events foster carbonate ion reduction in deep coral reefs

NASA Astrophysics Data System (ADS)

Perez, Fiz F.; Fontela, Marcos; Garcia-Ibañez, Maribel I.; Lherminier, Pascale; Zunino, Patricia; de la Paz, Mercedes; Padín, Xose A.; Alonso-Pérez, Fernando; Velo, Anton; Guallart, Elisa F.; Mercier, Herle

2017-04-01

Since millennial times, water mass circulation and deep-convection events have been transforming warm upper waters at high latitudes into cold and well-oxygenated deep waters. These processes have filled the deep North Atlantic Ocean with waters moderately saturated in calcium carbonate, thus promoting the growth of stony corals, which are hotspots of biodiversity. During the Anthropocene, the meridional circulation has been conveying cumulative amounts of more acidified waters with lower calcium carbonate saturation levels due to the incorporation of anthropogenic carbon dioxide, with very harsh conditions for deep cold-water corals projected by 2100. We evaluate the diminution of calcium carbonate saturation levels (aragonite form) due to the increase in anthropogenic carbon dioxide during the last two decades (2002-2016). We observe a strong decrease in the aragonite saturation levels concomitant with the reduction in the volume transport of aragonite-saturated waters. We estimate a 30-35% reduction in the transport of ion carbonate excess over the saturation levels with respect to the natural carbon cycle for the period 2002-2016. This reduction is associated with an increase in the downward transport of hydrogen ions. We also observe a heaving of the aragonite saturation horizons during the last 25 years, which is estimated at 6 m year-1 for the deep waters and 12-14 m year-1 for the intermediated waters. The harsh winters of 2015 and 2016 have fostered the fast addition of more acidified water into the lower layers of the North Atlantic through deep-convection events. In the future scenario of 2oC warming, the anthropogenic carbon dioxide in the water column would be double than today and the associated transport of hydrogen ions towards the bottom water would reduce the aragonite saturation levels to 60-80% with respect to preindustrial levels. This reduction in the aragonite saturation levels would suppose a strong diminution of the North Atlantic habitats where stony corals will be able to inhabit.

WATER MASERS IN THE ANDROMEDA GALAXY. I. A SURVEY FOR WATER MASERS, AMMONIA, AND HYDROGEN RECOMBINATION LINES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darling, Jeremy; Gerard, Benjamin; Amiri, Nikta

We report the results of a Green Bank Telescope survey for water masers, ammonia (1, 1) and (2, 2), and the H66 α recombination line toward 506 luminous compact 24 μ m emitting regions in the Andromeda Galaxy (M31). We include the 206 sources observed in the Darling water maser survey for completeness. The survey was sensitive enough to detect any maser useful for ∼10 μ as yr{sup 1} astrometry. No new water masers, ammonia lines, or H66 α recombination lines were detected individually or in spectral stacks reaching rms noise levels of ∼3 mJy and ∼0.2 mJy, respectively, inmore » 3.1–3.3 km s{sup 1} channels. The lack of detections in individual spectra and in the spectral stacks is consistent with Galactic extrapolations. Contrary to previous assertions, there do not seem to be any additional bright water masers to be found in M31. The strong variability of water masers may enable new maser detections in the future, but variability may also limit the astrometric utility of known (or future) masers because flaring masers must also fade.« less

Effect of Pumping on Groundwater Levels: A Case Study

NASA Astrophysics Data System (ADS)

Sindhu, G.; Vijayachandran, Lekshmi

2018-03-01

Groundwater is a major source for drinking and domestic purposes. Nowadays, extensive pumping has become a major issue of concern since pumping has led to rapid decline in the groundwater table, thus imposing landward gradient, leading to saline water intrusion especially in coastal areas. Groundwater pumping has seen its utmost effect on coastal aquifer systems, where the sea-ward gradient gets disturbed due to anthropogenic influences. Hence, a groundwater flow modelling of an aquifer system is essential for understanding the various hydro-geologic conditions, which can be used to study the responses of the aquifer system with regard to various pumping scenarios. Besides, a model helps to predict the water levels for the future period with respect to changing environment. In this study, a finite element groundwater flow model of a coastal aquifer system at Aakulam, Trivandrum district is developed, calibrated and simulated using the software Finite Element subsurface Flow system (FEFLOW 6.2).This simulated model is then used to predict the groundwater levels for a future 5 year period during pre monsoon and post monsoon season.

Effect of Pumping on Groundwater Levels: A Case Study

NASA Astrophysics Data System (ADS)

Sindhu, G.; Vijayachandran, Lekshmi

2018-06-01

Groundwater is a major source for drinking and domestic purposes. Nowadays, extensive pumping has become a major issue of concern since pumping has led to rapid decline in the groundwater table, thus imposing landward gradient, leading to saline water intrusion especially in coastal areas. Groundwater pumping has seen its utmost effect on coastal aquifer systems, where the sea-ward gradient gets disturbed due to anthropogenic influences. Hence, a groundwater flow modelling of an aquifer system is essential for understanding the various hydro-geologic conditions, which can be used to study the responses of the aquifer system with regard to various pumping scenarios. Besides, a model helps to predict the water levels for the future period with respect to changing environment. In this study, a finite element groundwater flow model of a coastal aquifer system at Aakulam, Trivandrum district is developed, calibrated and simulated using the software Finite Element subsurface Flow system (FEFLOW 6.2).This simulated model is then used to predict the groundwater levels for a future 5 year period during pre monsoon and post monsoon season.

Modelling the response of shallow groundwater levels to combined climate and water-diversion scenarios in Beijing-Tianjin-Hebei Plain, China

NASA Astrophysics Data System (ADS)

Li, Xue; Ye, Si-Yuan; Wei, Ai-Hua; Zhou, Peng-Peng; Wang, Li-Heng

2017-09-01

A three-dimensional groundwater flow model was implemented to quantify the temporal variation of shallow groundwater levels in response to combined climate and water-diversion scenarios over the next 40 years (2011-2050) in Beijing-Tianjin-Hebei (Jing-Jin-Ji) Plain, China. Groundwater plays a key role in the water supply, but the Jing-Jin-Ji Plain is facing a water crisis. Groundwater levels have declined continuously over the last five decades (1961-2010) due to extensive pumping and climate change, which has resulted in decreased recharge. The implementation of the South-to-North Water Diversion Project (SNWDP) will provide an opportunity to restore the groundwater resources. The response of groundwater levels to combined climate and water-diversion scenarios has been quantified using a groundwater flow model. The impacts of climate change were based on the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset for future high (A2), medium (A1B), and low (B1) greenhouse gas scenarios; precipitation data from CMIP3 were applied in the model. The results show that climate change will slow the rate of decrease of the shallow groundwater levels under three climate-change scenarios over the next 40 years compared to the baseline scenario; however, the shallow groundwater levels will rise significantly (maximum of 6.71 m) when considering scenarios that combine climate change and restrictions on groundwater exploitation. Restrictions on groundwater exploitation for water resource management are imperative to control the decline of levels in the Jing-Jin-Ji area.

Norfolk, Virginia—Planning to be the Coastal Community of the Future in a rising water environment

NASA Astrophysics Data System (ADS)

Homewood, G. M.

2017-12-01

Norfolk VA is the second most at-risk population center in North America from sea level rise while also being home to the world's largest naval base and one of the 3 largest east coast ports. Norfolk is one of the original cohort of cities in the 100 Resilient Cities effort pioneered by the Rockefeller Foundation and has changed its sea level adaptation strategy from "keep the water out" to "living with water" through a ground-breaking community visioning process. In Norfolk, this means, among other goals, finding co-benefits in public and private investments and interventions—these can be environmental, economic, social, recreational or other things we have not yet thought about—and it is in this area that the geosciences can benefit Norfolk's planning for a rising water environment.

SENTINEL-1/2 Data for Ship Traffic Monitoring on the Danube River

NASA Astrophysics Data System (ADS)

Negula, I. Dana; Poenaru, V. D.; Olteanu, V. G.; Badea, A.

2016-06-01

After a long period of drought, the water level of the Danube River has significantly dropped especially on the Romanian sector, in July-August 2015. Danube reached the lowest water level recorded in the last 12 years, causing the blockage of the ships in the sector located close to Zimnicea Harbour. The rising sand banks in the navigable channel congested the commercial traffic for a few days with more than 100 ships involved. The monitoring of the decreasing water level and the traffic jam was performed based on Sentinel-1 and Sentinel-2 free data provided by the European Space Agency and the European Commission within the Copernicus Programme. Specific processing methods (calibration, speckle filtering, geocoding, change detection, image classification, principal component analysis, etc.) were applied in order to generate useful products that the responsible authorities could benefit from. The Sentinel data yielded good results for water mask extraction and ships detection. The analysis continued after the closure of the crisis situation when the water reached the nominal level again. The results indicate that Sentinel data can be successfully used for ship traffic monitoring, building the foundation of future endeavours for a durable monitoring of the Danube River.

Development of adaptation strategies of marshland water management to regional climate change

NASA Astrophysics Data System (ADS)

Bormann, Helge; Frank, Ahlhorn; Luise, Giani; Kirsten, Klaassen; Thomas, Klenke

2010-05-01

Since many centuries, low lying areas at the German North Sea coast are intensively managed by water boards and dike boards. Sophisticated water management systems have been developed in order to keep the water out of the low lying areas in wet periods, while in some regions additional water is needed in dry periods for agricultural and ecological purposes. For example in the Wesermarsch region, a water management system has been developed in historical times, draining the landscape in winter time by means of channels, ditches, gates, sluices and pumping stations. In contrast, in summer time water is conducted from Weser River into the Wesermarsch region to serve watering of animals, fencing grazing areas and ensuring a continuous flow in the marsh watercourses. Doing so, maintaining soil fertility is guaranteed for agriculture as well as protection against floods, sustaining river ecology and traditional livestock farming. Due to climate variability and river engineering, the water management of the Wesermarsch already runs into problems because watering in summer cannot be assured any longer in sufficient water quality. During high tides, salt water from the North Sea is flowing upstream into the Weser estuary, generating brackish conditions in the lower Weser River. In addition, soil subsidence and soil mineralization of marsh and peat soils as well as the sea level rise increase the necessary pumping frequency and the emerging energy costs. The expected future climate change will further aggravate those problems and require an adaptation of the current management system. This presentation introduces the concept behind and preliminary results of an integrative and participatory project, aiming at the development of a new water management strategy adapted to the regional climate change likely to occur until year 2050. In close cooperation with a number of regional stakeholders and based on the priorities with respect to the future development of the region, alternative strategies for a future water management were developed. They are based on the stakeholder's picture of their future landscape, describing how the region should look like in year 2050, considering the landscape in general as well as socioeconomic aspects such as land use, employment market and tourism. And they are also based on guiding principles of future water management on which all stakeholders agreed. In comparison with the list of potential measures suggested by regional stakeholders, a concept is presented which was developed by a group of international water management experts from Netherlands, UK, Sweden and Belgium in the framework of a project workshop of the EU-Interreg IVb ‘Climate Proof Areas' project. This comparison highlights the impact of setting certain boundary conditions of a future development, i.e. the sustainable development of the future landscape versus keeping the landscape and its cultural heritage as it is now, for example by maintaining the traditional farming system as fundamental precondition for the climate adaptation process. Setting these priorities governs the decision making process and decides whether the focus is set on technical adaptation measures in contrast to alternative land use concepts for a region.

Projected impact of climate change and chemical emissions on the water quality of the European rivers Rhine and Meuse: A drinking water perspective.

PubMed

Sjerps, Rosa M A; Ter Laak, Thomas L; Zwolsman, Gertjan J J G

2017-12-01

Low river discharges of the rivers Rhine and Meuse are expected to occur more often and more prolonged in a changing climate. During these dry periods the dilution of point sources such as sewage effluents is reduced leading to a decline in chemical water quality. This study projects chemical water quality of the rivers Rhine and Meuse in the year 2050, based on projections of chemical emissions and two climate scenarios: moderate and fast climate change. It focuses on specific compounds known to be relevant to drinking water production, i.e. four pharmaceuticals, a herbicide and its metabolite and an artificial sweetener. Hydrological variability, climate change, and increased emission show a significant influence on the water quality in the Rhine and Meuse. The combined effect of changing future emissions of these compounds and reduced dilution due to climate change has leaded to increasing (peak) concentrations in the river water by a factor of two to four. Current water treatment efficiencies in the Netherlands are not sufficient to reduce these projected concentrations in drinking water produced from surface water below precautionary water target values. If future emissions are not sufficiently reduced or treatment efficiencies are not improved, these compounds will increasingly be found in drinking water, albeit at levels which pose no threat to human health. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessing Climate Vulnerability and Resilience of a Major Water Resource System - Inverting the Paradigm for Specific Risk Quantification at Decision Making Points of Impact

NASA Astrophysics Data System (ADS)

Murphy, K. W.; Ellis, A. W.; Skindlov, J. A.

2015-12-01

Water resource systems have provided vital support to transformative growth in the Southwest United States and the Phoenix, Arizona metropolitan area where the Salt River Project (SRP) currently satisfies 40% of the area's water demand from reservoir storage and groundwater. Large natural variability and expectations of climate changes have sensitized water management to risks posed by future periods of excess and drought. The conventional approach to impacts assessment has been downscaled climate model simulations translated through hydrologic models; but, scenario ranges enlarge as uncertainties propagate through sequential levels of modeling complexity. The research often does not reach the stage of specific impact assessments, rendering future projections frustratingly uncertain and unsuitable for complex decision-making. Alternatively, this study inverts the common approach by beginning with the threatened water system and proceeding backwards to the uncertain climate future. The methodology is built upon reservoir system response modeling to exhaustive time series of climate-driven net basin supply. A reservoir operations model, developed with SRP guidance, assesses cumulative response to inflow variability and change. Complete statistical analyses of long-term historical watershed climate and runoff data are employed for 10,000-year stochastic simulations, rendering the entire range of multi-year extremes with full probabilistic characterization. Sets of climate change projections are then translated by temperature sensitivity and precipitation elasticity into future inflow distributions that are comparatively assessed with the reservoir operations model. This approach provides specific risk assessments in pragmatic terms familiar to decision makers, interpretable within the context of long-range planning and revealing a clearer meaning of climate change projections for the region. As a transferable example achieving actionable findings, the approach can guide other communities confronting water resource planning challenges.

The Spatial Distributions and Variations of Water Environmental Risk in Yinma River Basin, China

PubMed Central

Di, Hui; Liu, Xingpeng; Tong, Zhijun; Ji, Meichen

2018-01-01

Water environmental risk is the probability of the occurrence of events caused by human activities or the interaction of human activities and natural processes that will damage a water environment. This study proposed a water environmental risk index (WERI) model to assess the water environmental risk in the Yinma River Basin based on hazards, exposure, vulnerability, and regional management ability indicators in a water environment. The data for each indicator were gathered from 2000, 2005, 2010, and 2015 to assess the spatial and temporal variations in water environmental risk using particle swarm optimization and the analytic hierarchy process (PSO-AHP) method. The results showed that the water environmental risk in the Yinma River Basin decreased from 2000 to 2015. The risk level of the water environment was high in Changchun, while the risk levels in Yitong and Yongji were low. The research methods provide information to support future decision making by the risk managers in the Yinma River Basin, which is in a high-risk water environment. Moreover, water environment managers could reduce the risks by adjusting the indicators that affect water environmental risks. PMID:29543706

Under-estimated wave contribution to coastal sea-level rise

NASA Astrophysics Data System (ADS)

Melet, Angélique; Meyssignac, Benoit; Almar, Rafael; Le Cozannet, Gonéri

2018-03-01

Coastal communities are threatened by sea-level changes operating at various spatial scales; global to regional variations are associated with glacier and ice sheet loss and ocean thermal expansion, while smaller coastal-scale variations are also related to atmospheric surges, tides and waves. Here, using 23 years (1993-2015) of global coastal sea-level observations, we examine the contribution of these latter processes to long-term sea-level rise, which, to date, have been relatively less explored. It is found that wave contributions can strongly dampen or enhance the effects of thermal expansion and land ice loss on coastal water-level changes at interannual-to-multidecadal timescales. Along the US West Coast, for example, negative wave-induced trends dominate, leading to negative net water-level trends. Accurate estimates of past, present and future coastal sea-level rise therefore need to consider low-frequency contributions of wave set-up and swash.

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

PubMed

Susko, Michele L; Bloom, Michael S; Neamtiu, Iulia A; Appleton, Allison A; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F; Anastasiu, Doru; Gurzau, Eugen S

2017-04-01

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiṣ County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. Copyright © 2016 Elsevier Inc. All rights reserved.

Low-level arsenic exposure via drinking water consumption and female fecundity - a preliminary investigation

PubMed Central

Susko, Michele L.; Bloom, Michael S.; Neamtiu, Iulia A.; Appleton, Allison A.; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F.; Anastasiu, Doru; Gurzau, Eugen S.

2017-01-01

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiş County, Romania. Women (n = 94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women For example, 1 μg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P = 0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. PMID:28061371

Topsoil structure stability in a restored floodplain: Impacts of fluctuating water levels, soil parameters and ecosystem engineers.

PubMed

Schomburg, A; Schilling, O S; Guenat, C; Schirmer, M; Le Bayon, R C; Brunner, P

2018-10-15

Ecosystem services provided by floodplains are strongly controlled by the structural stability of soils. The development of a stable structure in floodplain soils is affected by a complex and poorly understood interplay of hydrological, physico-chemical and biological processes. This paper aims at analysing relations between fluctuating groundwater levels, soil physico-chemical and biological parameters on soil structure stability in a restored floodplain. Water level fluctuations in the soil are modelled using a numerical surface-water-groundwater flow model and correlated to soil physico-chemical parameters and abundances of plants and earthworms. Causal relations and multiple interactions between the investigated parameters are tested through structural equation modelling (SEM). Fluctuating water levels in the soil did not directly affect the topsoil structure stability, but indirectly through affecting plant roots and soil parameters that in turn determine topsoil structure stability. These relations remain significant for mean annual days of complete and partial (>25%) water saturation. Ecosystem functioning of a restored floodplain might already be affected by the fluctuation of groundwater levels alone, and not only through complete flooding by surface water during a flood period. Surprisingly, abundances of earthworms did not show any relation to other variables in the SEM. These findings emphasise that earthworms have efficiently adapted to periodic stress and harsh environmental conditions. Variability of the topsoil structure stability is thus stronger driven by the influence of fluctuating water levels on plants than by the abundance of earthworms. This knowledge about the functional network of soil engineering organisms, soil parameters and fluctuating water levels and how they affect soil structural stability is of fundamental importance to define management strategies of near-natural or restored floodplains in the future. Copyright © 2018 Elsevier B.V. All rights reserved.

Growth of soybean at future tropospheric ozone concentrations decreases canopy evapotranspiration and soil water depletion.

PubMed

Bernacchi, Carl J; Leakey, Andrew D B; Kimball, Bruce A; Ort, Donald R

2011-06-01

Tropospheric ozone is increasing in many agricultural regions resulting in decreased stomatal conductance and overall biomass of sensitive crop species. These physiological effects of ozone forecast changes in evapotranspiration and thus in the terrestrial hydrological cycle, particularly in intercontinental interiors. Soybean plots were fumigated with ozone to achieve concentrations above ambient levels over five growing seasons in open-air field conditions. Mean season increases in ozone concentrations ([O₃]) varied between growing seasons from 22 to 37% above background concentrations. The objective of this experiment was to examine the effects of future [O₃] on crop ecosystem energy fluxes and water use. Elevated [O₃] caused decreases in canopy evapotranspiration resulting in decreased water use by as much as 15% in high ozone years and decreased soil water removal. In addition, ozone treatment resulted in increased sensible heat flux in all years indicative of day-time increase in canopy temperature of up to 0.7 °C. Published by Elsevier Ltd.

Improving regional climate and hydrological forecasting following the record setting flooding across the Lake Ontario - St. Lawrence River system

NASA Astrophysics Data System (ADS)

Gronewold, A.; Seglenieks, F.; Bruxer, J.; Fortin, V.; Noel, J.

2017-12-01

In the spring of 2017, water levels across Lake Ontario and the upper St. Lawrence River exceeded record high levels, leading to widespread flooding, damage to property, and controversy over regional dam operating protocols. Only a few years earlier, water levels on Lakes Superior, Michigan, and Huron (upstream of Lake Ontario) had dropped to record low levels leading to speculation that either anthropogenic controls or climate change were leading to chronic water loss from the Great Lakes. The contrast between low water level conditions across Earth's largest lake system from the late 1990s through 2013, and the rapid rise prior to the flooding in early 2017, underscores the challenges of quantifying and forecasting hydrologic impacts of rising regional air and water temperatures (and associated changes in lake evaporation) and persistent increases in long-term precipitation. Here, we assess the hydrologic conditions leading to the recent record flooding across the Lake Ontario - St. Lawrence River system, with a particular emphasis on understanding the extent to which those conditions were consistent with observed and anticipated changes in historical and future climate, and the extent to which those conditions could have been anticipated through improvements in seasonal climate outlooks and hydrological forecasts.

How to meet the increasing demands of water, food and energy in the future?

NASA Astrophysics Data System (ADS)

Shi, Haiyun; Chen, Ji; Sivakumar, Bellie; Peart, Mervyn

2017-04-01

Regarded as a driving force in water, food and energy demands, the world's population has been increasing rapidly since the beginning of the 20th century. According to the medium-growth projection scenario of the United Nations, the world's population will reach 9.5 billion by 2050. In response to the continuously growing population during this century, water, food and energy demands have also been increasing rapidly, and social problems (e.g., water, food, and energy shortages) will be most likely to occur, especially if no proper management strategies are adopted. Then, how to meet the increasing demands of water, food and energy in the future? This study focuses on the sustainable developments of population, water, food, energy and dams, and the significances of this study can be concluded as follows: First, we reveal the close association between dams and social development through analysing the related data for the period 1960-2010, and argue that construction of additional large dams will have to be considered as one of the best available options to meet the increasing water, food and energy demands in the future. We conduct the projections of global water, food and energy consumptions and dam development for the period 2010-2050, and the results show that, compared to 2010, the total water, food and energy consumptions in 2050 will increase by 20%, 34% and 37%, respectively. Moreover, it is projected that additional 4,340 dams will be constructed by 2050 all over the world. Second, we analyse the current situation of global water scarcity based on the related data representing water resources availability (per capita available water resources), dam development (the number of dams), and the level of economic development (per capita gross domestic product). At the global scale, water scarcity exists in more than 70% of the countries around the world, including 43 countries suffering from economic water scarcity and 129 countries suffering from physical water scarcity. At the continental scale, most countries of Africa, the south and west Asia, and the central Europe are suffering from water scarcity. Third, with comprehensive consideration of population growth as the major driving force, water resources availability as the basic supporting factor, and topography as the important constraint, we address the question of future dam development and predict the locations of future large dams around the world. The results show that there will be 1,433 large dams built in the future, mainly in the Tibet Plateau and the Yunnan-Guizhou Plateau in Asia, the East African Plateau and the western part of Africa, the Andes Mountains and the Brazilian Plateau region in South America, the Rocky Mountains in North America, the Alps in Europe, and the Murray-Darling Basin in Oceania. Taking into account of the current situation of global water scarcity, these large dams are most likely to be constructed in countries that have abundant total available water resources or per capita available water resources, no matter whether they are experiencing "economic water scarcity" or have sufficient financial support.

A Case Study of Environmental Injustice: The Failure in Flint

PubMed Central

Campbell, Carla; Greenberg, Rachael; Mankikar, Deepa; Ross, Ronald D.

2016-01-01

The failure by the city of Flint, Michigan to properly treat its municipal water system after a change in the source of water, has resulted in elevated lead levels in the city’s water and an increase in city children’s blood lead levels. Lead exposure in young children can lead to decrements in intelligence, development, behavior, attention and other neurological functions. This lack of ability to provide safe drinking water represents a failure to protect the public’s health at various governmental levels. This article describes how the tragedy happened, how low-income and minority populations are at particularly high risk for lead exposure and environmental injustice, and ways that we can move forward to prevent childhood lead exposure and lead poisoning, as well as prevent future Flint-like exposure events from occurring. Control of the manufacture and use of toxic chemicals to prevent adverse exposure to these substances is also discussed. Environmental injustice occurred throughout the Flint water contamination incident and there are lessons we can all learn from this debacle to move forward in promoting environmental justice. PMID:27690065

A Case Study of Environmental Injustice: The Failure in Flint.

PubMed

Campbell, Carla; Greenberg, Rachael; Mankikar, Deepa; Ross, Ronald D

2016-09-27

The failure by the city of Flint, Michigan to properly treat its municipal water system after a change in the source of water, has resulted in elevated lead levels in the city's water and an increase in city children's blood lead levels. Lead exposure in young children can lead to decrements in intelligence, development, behavior, attention and other neurological functions. This lack of ability to provide safe drinking water represents a failure to protect the public's health at various governmental levels. This article describes how the tragedy happened, how low-income and minority populations are at particularly high risk for lead exposure and environmental injustice, and ways that we can move forward to prevent childhood lead exposure and lead poisoning, as well as prevent future Flint-like exposure events from occurring. Control of the manufacture and use of toxic chemicals to prevent adverse exposure to these substances is also discussed. Environmental injustice occurred throughout the Flint water contamination incident and there are lessons we can all learn from this debacle to move forward in promoting environmental justice.

Modification of land-atmosphere interactions by CO2 effects: Implications for summer dryness and heat wave amplitude

NASA Astrophysics Data System (ADS)

Lemordant, Léo.; Gentine, Pierre; Stéfanon, Marc; Drobinski, Philippe; Fatichi, Simone

2016-10-01

Plant stomata couple the energy, water, and carbon cycles. We use the framework of Regional Climate Modeling to simulate the 2003 European heat wave and assess how higher levels of surface CO2 may affect such an extreme event through land-atmosphere interactions. Increased CO2 modifies the seasonality of the water cycle through stomatal regulation and increased leaf area. As a result, the water saved during the growing season through higher water use efficiency mitigates summer dryness and the heat wave impact. Land-atmosphere interactions and CO2 fertilization together synergistically contribute to increased summer transpiration. This, in turn, alters the surface energy budget and decreases sensible heat flux, mitigating air temperature rise. Accurate representation of the response to higher CO2 levels and of the coupling between the carbon and water cycles is therefore critical to forecasting seasonal climate, water cycle dynamics, and to enhance the accuracy of extreme event prediction under future climate.

Assessment of the Physicochemical Quality of Drinking Water Resources in the Central Part of Iran.

PubMed

Nikaeen, Mahnaz; Shahryari, Ali; Hajiannejad, Mehdi; Saffari, Hossein; Kachuei, Zahra Moosavian; Hassanzadeh, Akbar

2016-01-01

The aim of the study described in this article was to assess the physicochemical quality of water resources in Isfahan province, located in the central part of Iran, from June to November 2012. Comparison of the results with the acceptable limits recommended by the World Health Organization (WHO) for drinking water showed that nitrate, chloride, iron, and fluoride concentrations exceeded the maximum acceptable level in 12.3%, 9.2%, 6.8%, and 1.5% of samples, respectively. Total dissolved solids (TDS) and turbidity values also exceeded the maximum acceptable level in 9.2% and 3.1% of samples, respectively. In general, the quality of drinking water resources in the central part of Iran at present is mostly acceptable and satisfactory. It may be deteriorated in the future, however, because water quantity and quality in arid and semiarid areas are highly variable over time. Therefore, continued monitoring of the water resources quality is extremely important to environmental safety.

The NASA/USDA Reservoir and Lake Monitor: Present and Future Capabilities and Water Resources Applications

NASA Astrophysics Data System (ADS)

Birkett, C. M.; Beckley, B. D.; Reynolds, C. A.; Brakenridge, G. R.; Ricko, M.

2013-12-01

The USDA/NASA Global Reservoir and Lake Monitor (GRLM) provides satellite-based surface water level products for large reservoirs and lakes around the world. It utilizes a suite of NASA/CNES and ESA radar altimetry data sets and outputs near real time and archival products via a web interface. Several stakeholders utilize the products for applications that focus on water resources management and natural hazards mitigation, particularly in arid and semi-arid regions. The satellite data sets prove particularly useful in un-gauged or poorly gauged basins where in situ data is sparse. Here, we present water-level product examples based on data from the NASA/CNES Jason-2/OSTM mission, and the new ISRO/CNES SARAL mission. We also demonstrate product application from the viewpoint of various end users who have interests ranging from crop production and fisheries, to regional security and climate change. In the current phase of the program the team is also looking to the potential of additional lake/reservoir products such as areal extent (NASA/MODIS), lake volume variations (combined altimetry/imagery), and model-derived water levels, that will enhance the GRLM via improved observation and prediction, and provide a more global lake basin monitoring capability. Surface water level variations for Lake Nasser.

The Community Water Model (CWATM) / Development of a community driven global water model

NASA Astrophysics Data System (ADS)

Burek, Peter; Satoh, Yusuke; Greve, Peter; Kahil, Taher; Wada, Yoshihide

2017-04-01

With a growing population and economic development, it is expected that water demands will increase significantly in the future, especially in developing regions. At the same time, climate change is expected to alter spatial patterns of hydrological cycle and will have global, regional and local impacts on water availability. Thus, it is important to assess water supply, water demand and environmental needs over time to identify the populations and locations that will be most affected by these changes linked to water scarcity, droughts and floods. The Community Water Model (CWATM) will be designed for this purpose in that it includes an accounting of how future water demands will evolve in response to socioeconomic change and how water availability will change in response to climate. CWATM represents one of the new key elements of IIASA's Water program. It has been developed to work flexibly at both global and regional level at different spatial resolutions. The model is open source and community-driven to promote our work amongst the wider water community worldwide and is flexible enough linking to further planned developments such as water quality and hydro-economic modules. CWATM will be a basis to develop a next-generation global hydro-economic modeling framework that represents the economic trade-offs among different water management options over a basin looking at water supply infrastructure and demand managements. The integrated modeling framework will consider water demand from agriculture, domestic, energy, industry and environment, investment needs to alleviate future water scarcity, and will provide a portfolio of economically optimal solutions for achieving future water management options under the Sustainable Development Goals (SDG) for example. In addition, it will be able to track the energy requirements associated with the water supply system e.g., pumping, desalination and interbasin transfer to realize the linkage with the water-energy economy. In a bigger framework of nexus - water, energy, food, ecosystem - CWATM will be coupled to the existing IIASA models including the Integrated Assessment Model MESSAGE and the global land and ecosystem model GLOBIOM in order to realize an improved assessments of water-energy-food-ecosystem nexus and associated feedback. Our vision for the short to medium term work is to introduce water quality (e.g., salinization in deltas and eutrophication associated with mega cities) into CWATM and to consider qualitative and quantitative measures of transboundary river and groundwater governance into an integrated modelling framework.

Ground-Water Data for Indian Wells Valley, Kern, Inyo, and San Bernardino Counties, California, 1977-84

USGS Publications Warehouse

Berenbrock, Charles

1987-01-01

Ground water is the sole source of water in Indian Wells Valley. Since 1966, annual ground-water pumpage has exceeded estimates of mean annual recharge, and continued and increased stresses on the aquifer system of the valley are expected. In 1981 the U.S. Geological Survey began a 10-year program to develop a data base that could be used in evaluating future water-management alternatives for the valley. This report tabulates existing water-level and water-quality data in order to provide a basis for the design of a ground-water monitoring network for Indian Wells Valley. Water-levels were measured in 131 wells during 1977-84. About 62 percent of the wells that have water-level measurements spanning at least 3 years during the period 1977-84 show a net water-level decline; the decline in 23 percent of the wells is greater than 5 feet. Water-quality samples from 85 wells were analyzed for major dissolved constituents. At selected wells water samples were also analyzed for nutrients and trace metals. Seventy-nine of the wells sampled contained water with concentrations of one or more dissolved constituents that equaled or exceeded U.S. Environmental Protection Agency primary or secondary maximum contaminant levels for drinking water. Dissolved-solids concentrations, which ranged from 190 to 67,000 milligrams per liter, equaled or exceeded 500 milligrams per liter (the Environmental Protection Agency secondary maximum contaminant level) in 85 percent of the sampled wells and 1,000 milligrams per liter in 59 percent. Water samples collected in 1984 from eight wells near the industrial-waste ponds of the China Lake Naval Weapons Center were analyzed for the presence of organic compounds designated 'priority pollutants' by the U.S. Environmental Protection Agency. Priority pollutants were detected in three wells. Trichloroethylene, methylene chloride, vinyl chloride, and chloroform were identified; concentrations were less than 10 micrograms per liter except for trichloroethylene and chloroform, at 94 and 12 micrograms per liter, respectively. Trichloroethylene in one sample and vinyl chloride in another exceeded Environmental Protection Agency proposed maximum contaminant levels.

U.S. Geological Survey Groundwater Modeling Software: Making Sense of a Complex Natural Resource

USGS Publications Warehouse

Provost, Alden M.; Reilly, Thomas E.; Harbaugh, Arlen W.; Pollock, David W.

2009-01-01

Computer models of groundwater systems simulate the flow of groundwater, including water levels, and the transport of chemical constituents and thermal energy. Groundwater models afford hydrologists a framework on which to organize their knowledge and understanding of groundwater systems, and they provide insights water-resources managers need to plan effectively for future water demands. Building on decades of experience, the U.S. Geological Survey (USGS) continues to lead in the development and application of computer software that allows groundwater models to address scientific and management questions of increasing complexity.

Modeling the potential impacts of climate change on the water table level of selected forested wetlands in the southeastern United States

NASA Astrophysics Data System (ADS)

Zhu, Jie; Sun, Ge; Li, Wenhong; Zhang, Yu; Miao, Guofang; Noormets, Asko; McNulty, Steve G.; King, John S.; Kumar, Mukesh; Wang, Xuan

2017-12-01

The southeastern United States hosts extensive forested wetlands, providing ecosystem services including carbon sequestration, water quality improvement, groundwater recharge, and wildlife habitat. However, these wetland ecosystems are dependent on local climate and hydrology, and are therefore at risk due to climate and land use change. This study develops site-specific empirical hydrologic models for five forested wetlands with different characteristics by analyzing long-term observed meteorological and hydrological data. These wetlands represent typical cypress ponds/swamps, Carolina bays, pine flatwoods, drained pocosins, and natural bottomland hardwood ecosystems. The validated empirical models are then applied at each wetland to predict future water table changes using climate projections from 20 general circulation models (GCMs) participating in Coupled Model Inter-comparison Project 5 (CMIP5) under the Representative Concentration Pathways (RCPs) 4.5 and 8.5 scenarios. We show that combined future changes in precipitation and potential evapotranspiration would significantly alter wetland hydrology including groundwater dynamics by the end of the 21st century. Compared to the historical period, all five wetlands are predicted to become drier over time. The mean water table depth is predicted to drop by 4 to 22 cm in response to the decrease in water availability (i.e., precipitation minus potential evapotranspiration) by the year 2100. Among the five examined wetlands, the depressional wetland in hot and humid Florida appears to be most vulnerable to future climate change. This study provides quantitative information on the potential magnitude of wetland hydrological response to future climate change in typical forested wetlands in the southeastern US.

Groundwater Regulation in the Houston-Galveston Region to Control Subsidence - Balancing Total Water Demand, Available Alternative Water Supplies, and Groundwater Withdrawal

NASA Astrophysics Data System (ADS)

Turco, M. J.

2014-12-01

In 1975, as a result of area residents and local governments becoming increasingly alarmed by the continued impact of subsidence on economic growth and quality of life in the region, the Harris-Galveston Coastal Subsidence District was created by the 64th Texas Legislature as an underground water conservation district. The primary mission of what is now the Harris-Galveston Subsidence District, is to provide for the regulation of the withdrawal of groundwater to control subsidence. Subsidence has been a concern in the Houston, TX area throughout most of recent history. Since 1906, over 10 feet of subsidence has occurred, with a broad area of 6 feet of subsidence throughout most of the Houston Area.Over its nearly forty years of existence, the District has developed substantial data sets providing the foundation for its regulatory plan. Annual water-level measurements, a network of deep extensometers, over 80 subsidence GPS monitors, and updated numerical and analytical models have been utilized. Periodically, the District utilizes U.S. Census data to predict the future magnitude and location of population and water demand. In 2013, all of these data sets were combined producing an updated regulatory plan outlining the timelines of conversion to alternative sources of water and defining the maximum percentage groundwater can contribute to a user's total water demand.The management of the groundwater resources within the District has involved significant coordination with regional ground and surface water suppliers; ongoing interaction with other state and local regulatory bodies; analysis of accurate and up to date predictions on water usage; the enforcement of real disincentives to those who rely too heavily on groundwater and a commitment to practicing and promoting water conservation.Water supplies in the region are projected to continue to be stressed in the future due to rapid population increases in the region. Future District efforts will be focused on maintaining the successes of the past while evaluating potential deeper groundwater resources and any potential subsidence resulting from future development.

A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

PubMed

van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

2008-12-01

This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

Global energy consumption for direct water use

NASA Astrophysics Data System (ADS)

Liu, Y.; Hejazi, M. I.; Kim, S. H.; Kyle, P.; Davies, E. G.; Miralles, D. G.; Teuling, R.; He, Y.; Niyogi, D.

2015-12-01

Despite significant efforts to quantify the mutual inter-dependence of the water and energy sectors, global energy for water (EFW) remains poorly understood, resulting in biases in energy accounting that directly affect water and energy management and policy. We firstly evaluate the global energy consumption for direct water use from 1973 to 2012 with sectoral, regional and process-level details. Over the 40-year period, we detected multiple shifts in EFW by county and region. For example, we find that India, the Middle East and China have surpassed the United States as the three largest consumers of EFW since 2003, mostly because of rapid growth in groundwater-based irrigation, desalination, and industrial and municipal water use, respectively. Globally, EFW accounts for 1-3% of total primary energy consumption in 2010, of which 52% is surface water, 36% is groundwater, and 12% is non-fresh water. The sectoral allocation of EFW includes municipal (45%), industrial (29%), and agricultural use (26%), and process-level contributions are from source/conveyance (41%), water purification (19%), water distribution (13%) and wastewater treatment (22%). Our evaluation suggests that the EFW may increase in importance in the future due to growth in population and income, and depletion of surface and shallow aquifer water resources in water-scarce regions. We are incorporating this element into an integrated assessment model (IAM) and linking it back to energy balance within that IAM. By doing this, we will then explore the impacts of EFW on the global energy market (e.g., changes in the share of groundwater use and desalination), and the uncertainty of future EFW under different shared social pathway (SSP) and representative concentration pathway (RCP) scenarios, and consequences on the emission of greenhouse gases as well. We expect these EFW induced impacts will be considerable, and will then have significant implications for adaptive management and policy making.

The Impact of Global Warming on Precipitation Patterns in Ilorin and the Hydrological Balance of the Awun Basin

NASA Astrophysics Data System (ADS)

Ayanshola, Ayanniyi; Olofintoye, Oluwatosin; Obadofin, Ebenezer

2018-03-01

This study presents the impact of global warming on precipitation patterns in Ilorin, Nigeria, and its implications on the hydrological balance of the Awun basin under the prevailing climate conditions. The study analyzes 39 years of rainfall and temperature data of relevant stations within the study areas. Simulated data from the Coupled Global Climate model for historical and future datasets were investigated under the A2 emission scenario. Statistical regression and a Mann-Kendall analysis were performed to determine the nature of the trends in the hydrological variables and their significance levels, while a Soil and Water Assessment Tool (SWAT) was used to estimate the water balance and derive the stream flow and yield of the Awun basin. The study revealed that while minimum and maximum temperatures in Ilorin are increasing, rainfall is generally decreasing. The assessment of the trends in the water balance parameters in the basin indicates that there is no improvement in the water yield as the population increases. This may result in major stresses to the water supply in the near future.

Accounting for wetlands loss in a changing climate in the estimation of long-term flood risks of Devils Lake, North Dakota

NASA Astrophysics Data System (ADS)

Gulbin, S.; Kirilenko, A.; Zhang, X.

2016-12-01

Endorheic (terminal) lakes with no water outlets are sensitive indicators of changes in climate and land cover in the watershed. Regional variation in precipitation pattern in the US Northern Great Plaines lead to a long term flooding of Devils Lake (DL), ND, leading to a 10-m water level rise in just two decades, with estimated flood mitigation costs of over $1 billion. While the climate change contribution to flooding has been established, the role of large scale land conversion to agriculture has not been researched. Wetlands play a very important part in hydrological balance by storing, absorbing and slowing peak water discharge. In ND, 49 % of wetlands are drained and converted to agriculture. We investigated the role of wetlands loss in DL flooding in current and future climate. The Soil and Water Assessment Tool (SWAT) was used to simulate streamflow in all DL watershed subbasins. The model was calibrated using the 1991-2000 USGS gauge data for the first 10 years of study period and validated for the second 10 years (2001-2010), resulting in a satisfactory model performance compared against the measured water discharge in five streams in the watershed and against observed DL water level. A set of wetland loss scenarios were created based on the historical data and the Compound Topographic Index. To emulate the historical and future climate conditions, an ensemble of CMIP5 weather integrations based on IPCC AR5 RCP scenarios was downscaled with the MarkSim weather simulator. Model simulations indicate that the land use change in the DL watershed increased the impacts of climate change on hydrology by further elevating DL water level. Conversely, wetland restoration reduce the flooding and moderates risks of a potential high-impact DL overspill to the Sheyenne River watershed. Further research will concentrate on differentiation of climate change impacts under different types of land use change scenarios.

RECENT DEVELOPMENTS IN HYDROWEB DATABASE Water level time series on lakes and reservoirs (Invited)

NASA Astrophysics Data System (ADS)

Cretaux, J.; Arsen, A.; Calmant, S.

2013-12-01

We present the current state of the Hydroweb database as well as developments in progress. It provides offline water level time series on rivers, reservoirs and lakes based on altimetry data from several satellites (Topex/Poseidon, ERS, Jason-1&2, GFO and ENVISAT). The major developments in Hydroweb concerns the development of an operational data centre with automatic acquisition and processing of IGDR data for updating time series in near real time (both for lakes & rivers) and also use of additional remote sensing data, like satellite imagery allowing the calculation of lake's surfaces. A lake data centre is under development at the Legos in coordination with Hydrolare Project leaded by SHI (State Hydrological Institute of the Russian Academy of Science). It will provide the level-surface-volume variations of about 230 lakes and reservoirs, calculated through combination of various satellite images (Modis, Asar, Landsat, Cbers) and radar altimetry (Topex / Poseidon, Jason-1 & 2, GFO, Envisat, ERS2, AltiKa). The final objective is to propose a data centre fully based on remote sensing technique and controlled by in situ infrastructure for the Global Terrestrial Network for Lakes (GTN-L) under the supervision of WMO and GCOS. In a longer perspective, the Hydroweb database will integrate data from future missions (Jason-3, Jason-CS, Sentinel-3A/B) and finally will serve for the design of the SWOT mission. The products of hydroweb will be used as input data for simulation of the SWOT products (water height and surface variations of lakes and rivers). In the future, the SWOT mission will allow to monitor on a sub-monthly basis the worldwide lakes and reservoirs bigger than 250 * 250 m and Hydroweb will host water level and extent products from this

Present and Future Water Supply for Mammoth Cave National Park, Kentucky

USGS Publications Warehouse

Cushman, R.V.; Krieger, R.A.; McCabe, John A.

1965-01-01

The increase in the number of visitors during the past several years at Mammoth Cave National Park has rendered the present water supply inadequate. Emergency measures were necessary during August 1962 to supplement the available supply. The Green River is the largest potential source of water supply for Mammoth Cave. The 30-year minimum daily discharge is 40 mgd (million gallons per day) . The chemical quality is now good, but in the past the river has been contaminated by oil-field-brine wastes. By mixing it with water from the existing supply, Green River water could be diluted to provide water of satisfactory quality in the event of future brine pollution. The Nolin River is the next largest potential source of water (minimum releases from Nolin Reservoir, 97-129 mgd). The quality is satisfactory, but use of this source would require a 8-mile pipeline. The present water supply comes from springs draining a perched aquifer in the Haney Limestone Member of the Golconda Formation on Flint Ridge. Chemical quality is excellent but the minimum observed flow of all the springs on Flint Ridge plus Bransford well was only 121,700 gpd (gallons per day). This supply is adequate for present needs but not for future requirements; it could be augmented with water from the Green River. Wet Prong Buffalo Creek is the best of several small-stream supplies in the vicinity of Mammoth Cave. Minimum flow of the creek is probably about 300,000 gpd and the quality is good. The supply is about 5 miles from Mammoth Cave. This supply also may be utilized for a future separate development in the northern part of the park. The maximum recorded yield of wells drilled into the basal ground water in the Ste. Genevieve and St. Louis Limestone is 36 gpm (gallons per minute). Larger supplies may be developed if a large underground stream is struck. Quality can be expected to be good unless the well is drilled too far below the basal water table and intercepts poorer quality water at a lower level. This source of supply might be used to augment the present supply, but locating the trunk conduits might be difficult. Water in alluvium adjacent to the Green River and perched water in the Big Clifty Sandstone Member of the Golconda Formation and Girkin Formation have little potential as a water supply.

Reservoir operations under climate change: Storage capacity options to mitigate risk

NASA Astrophysics Data System (ADS)

Ehsani, Nima; Vörösmarty, Charles J.; Fekete, Balázs M.; Stakhiv, Eugene Z.

2017-12-01

Observed changes in precipitation patterns, rising surface temperature, increases in frequency and intensity of floods and droughts, widespread melting of ice, and reduced snow cover are some of the documented hydrologic changes associated with global climate change. Climate change is therefore expected to affect the water supply-demand balance in the Northeast United States and challenge existing water management strategies. The hydrological implications of future climate will affect the design capacity and operating characteristics of dams. The vulnerability of water resources systems to floods and droughts will increase, and the trade-offs between reservoir releases to maintain flood control storage, drought resilience, ecological flow, human water demand, and energy production should be reconsidered. We used a Neural Networks based General Reservoir Operation Scheme to estimate the implications of climate change for dams on a regional scale. This dynamic daily reservoir module automatically adapts to changes in climate and re-adjusts the operation of dams based on water storage level, timing, and magnitude of incoming flows. Our findings suggest that the importance of dams in providing water security in the region will increase. We create an indicator of the Effective Degree of Regulation (EDR) by dams on water resources and show that it is expected to increase, particularly during drier months of year, simply as a consequence of projected climate change. The results also indicate that increasing the size and number of dams, in addition to modifying their operations, may become necessary to offset the vulnerabilities of water resources systems to future climate uncertainties. This is the case even without considering the likely increase in future water demand, especially in the most densely populated regions of the Northeast.

Changes in environment, climate, land-use and population growth cause significant change in recharge on the western coast of Saudi Arabia

NASA Astrophysics Data System (ADS)

Prein, Angela; Weiß, Johannes

2013-04-01

Changes in climate, land-use and population do not necessarily lead to groundwater depletion, but could instead result in rising groundwater levels, which can cause severe problems. In the course of the refurbishment and expansion programme for the Holy City of Mecca (KSA), Jeddah Airport is being expanded to a greater capacity; in addition, rapid development of residential areas of Jeddah is underway. During the last, decade flash floods and rising groundwater levels have been observed. The latter are affecting the foundations of buildings due to uplift and corrosion by highly mineralized water. The primary objective of this study is investigate the causes of groundwater rise and to propose appropriate measures in order to keep the groundwater table below an acceptable level over the next 100 years. Groundwater hydrographs clearly show impacts of natural climatic and hydrologic changes over the last 30 years. Possibly reasons for groundwater rise in this arid area are climatic impacts by increased precipitation or from an enhanced recharge via wadi leakage or flood control reservoirs. In addition, anthropogenic impacts might arise from leakages from water supply and waste water systems. In order to identify and quantify possible contributions to groundwater recharge, a numerical groundwater model has been developed comprising a sound investigation of the local water balance. The model addresses an area of approximately 900 km around the city of Jeddah, reaching from the Red Sea to the catchment boundaries of adjacent wadis. Vertically three layers of alluvium, fractured and weathered rock are integrated. Information from many shallow boreholes and some deep boreholes comprising stratigraphy and hydraulic parameters is incorporated. The spatial distribution of recharge is taken from the analysis of existing and planned water supply and waste water networks. Knowledge from geophysical investigations about aquifer thickness and permeability was used for the transient calibration. Thus, from the groundwater rise with known storage coefficients the leakage was estimated and checked for plausibility. Model evaluation and sensitivity analysis include the identification of key model parameters, the parameter ranges for the prediction of groundwater levels and the characterization of associated uncertainties. The modelling results show that indeed the anthropogenic recharge caused by leakage from water infrastructure is the most important source of groundwater level rise. Thus, to improve model accuracy, a methodology is needed to cope with limited data availability regarding the leakage from pipelines. For the design of future management strategies, modelling scenarios are used to quantify the factors with possible impacts on groundwater levels, including Red Sea water level rise due to climate change, as well as potentially significant changes in land use, water distribution systems, waste water management, storm water and flood control, and irrigation. The model results are used for the design of a field-based groundwater and surface water monitoring system. Based on these measurements, a decision support system for future groundwater control is planned to be integrated into the upgrade of the water and waste water master plan.

Growing water scarcity in agriculture: future challenge to global water security.

PubMed

Falkenmark, Malin

2013-11-13

As water is an essential component of the planetary life support system, water deficiency constitutes an insecurity that has to be overcome in the process of socio-economic development. The paper analyses the origin and appearance of blue as well as green water scarcity on different scales and with particular focus on risks to food production and water supply for municipalities and industry. It analyses water scarcity originating from both climatic phenomena and water partitioning disturbances on different scales: crop field, country level and the global circulation system. The implications by 2050 of water scarcity in terms of potential country-level water deficits for food self-reliance are analysed, and the compensating dependence on trade in virtual water for almost half the world population is noted. Planetary-scale conditions for sustainability of the global water circulation system are discussed in terms of a recently proposed Planetary Freshwater Boundary, and the consumptive water use reserve left to be shared between water requirements for global food production, fuelwood production and carbon sequestration is discussed. Finally, the importance of a paradigm shift in the further conceptual development of water security is stressed, so that adequate attention is paid to water's fundamental role in both natural and socio-economic systems.

Impact of accelerated future global mean sea level rise on hypoxia in the Baltic Sea

NASA Astrophysics Data System (ADS)

Meier, H. E. M.; Höglund, A.; Eilola, K.; Almroth-Rosell, E.

2017-07-01

Expanding hypoxia is today a major threat for many coastal seas around the world and disentangling its drivers is a large challenge for interdisciplinary research. Using a coupled physical-biogeochemical model we estimate the impact of past and accelerated future global mean sea level rise (GSLR) upon water exchange and oxygen conditions in a semi-enclosed, shallow sea. As a study site, the Baltic Sea was chosen that suffers today from eutrophication and from dead bottom zones due to (1) excessive nutrient loads from land, (2) limited water exchange with the world ocean and (3) perhaps other drivers like global warming. We show from model simulations for the period 1850-2008 that the impacts of past GSLR on the marine ecosystem were relatively small. If we assume for the end of the twenty-first century a GSLR of +0.5 m relative to today's mean sea level, the impact on the marine ecosystem may still be small. Such a GSLR corresponds approximately to the projected ensemble-mean value reported by the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. However, we conclude that GSLR should be considered in future high-end projections (>+1 m) for the Baltic Sea and other coastal seas with similar hydrographical conditions as in the Baltic because GSLR may lead to reinforced saltwater inflows causing higher salinity and increased vertical stratification compared to present-day conditions. Contrary to intuition, reinforced ventilation of the deep water does not lead to overall improved oxygen conditions but causes instead expanded dead bottom areas accompanied with increased internal phosphorus loads from the sediments and increased risk for cyanobacteria blooms.

Comparing groundwater recharge and storage variability from GRACE satellite observations with observed water levels and recharge model simulations

NASA Astrophysics Data System (ADS)

Allen, D. M.; Henry, C.; Demon, H.; Kirste, D. M.; Huang, J.

2011-12-01

Sustainable management of groundwater resources, particularly in water stressed regions, requires estimates of groundwater recharge. This study in southern Mali, Africa compares approaches for estimating groundwater recharge and understanding recharge processes using a variety of methods encompassing groundwater level-climate data analysis, GRACE satellite data analysis, and recharge modelling for current and future climate conditions. Time series data for GRACE (2002-2006) and observed groundwater level data (1982-2001) do not overlap. To overcome this problem, GRACE time series data were appended to the observed historical time series data, and the records compared. Terrestrial water storage anomalies from GRACE were corrected for soil moisture (SM) using the Global Land Data Assimilation System (GLDAS) to obtain monthly groundwater storage anomalies (GRACE-SM), and monthly recharge estimates. Historical groundwater storage anomalies and recharge were determined using the water table fluctuation method using observation data from 15 wells. Historical annual recharge averaged 145.0 mm (or 15.9% of annual rainfall) and compared favourably with the GRACE-SM estimate of 149.7 mm (or 14.8% of annual rainfall). Both records show lows and peaks in May and September, respectively; however, the peak for the GRACE-SM data is shifted later in the year to November, suggesting that the GLDAS may poorly predict the timing of soil water storage in this region. Recharge simulation results show good agreement between the timing and magnitude of the mean monthly simulated recharge and the regional mean monthly storage anomaly hydrograph generated from all monitoring wells. Under future climate conditions, annual recharge is projected to decrease by 8% for areas with luvisols and by 11% for areas with nitosols. Given this potential reduction in groundwater recharge, there may be added stress placed on an already stressed resource.

Simulated effects of pumping and drought on ground-water levels and the freshwater-saltwater interface on the north fork of Long Island, New York

USGS Publications Warehouse

Misut, Paul E.; Schubert, Christopher E.; Bova, Richard G.; Colabufo, Steven R.

2004-01-01

Ground water is the sole source of freshwater on the North Fork of Long Island. Future demands for the limited freshwater supply during a prolonged drought could cause drawdowns that induce saltwater intrusion and render the supply unusable. The freshwater system on the North Fork contains several localized, hydraulically isolated aquifers bounded by salty water. The need for information on the ability of these aquifers to meet future demands prompted a 4-year study to develop a ground-water flow model to simulate several proposed pumping scenarios under long-term average conditions and during a hypothetical drought, and to delineate the resulting ground-water levels and movement of the freshwater-saltwater interface. The model code selected was SHARP, a quasi-three-dimensional finite-difference method of simulating freshwater and saltwater flow simultaneously.Two sets of four proposed pumping scenarios were evaluated. The first represented average recharge from precipitation during 2006-20; the second represented the same period and conditions except for a 5-year period of drought conditions. The average-recharge simulations used the long-term (1959-99) rate of recharge; the drought simulations applied a 20-percent reduction in recharge rate and a 20-percent increase in the 1999 rate of agricultural pumpage during 2011–15.The simulated movement of the freshwater-saltwater interface in future withdrawal and recharge scenarios indicates that the interface may rise beneath pumped wells at Inlet Drive, Brecknock Hall, Main Bayview Road, Islands End, North Road, and Alvah's Lane. Either (1) movement of the interface to within 50 feet of the well screen, (2) a large percent change in the distance between the interface and the well screen, or (3) movement of the interface through a clay layer is a cause for concern. Wellfields in which saltwater intrusion does not appear to be a cause for concern were those at Ackerly Pond, Kenney's Road, Middle Road, Rocky Point Road, and hypothetical sites where future wellfields have been proposed.

Response of groundwater level and surface-water/groundwater interaction to climate variability: Clarence-Moreton Basin, Australia

NASA Astrophysics Data System (ADS)

Cui, Tao; Raiber, Matthias; Pagendam, Dan; Gilfedder, Mat; Rassam, David

2018-03-01

Understanding the response of groundwater levels in alluvial and sedimentary basin aquifers to climatic variability and human water-resource developments is a key step in many hydrogeological investigations. This study presents an analysis of groundwater response to climate variability from 2000 to 2012 in the Queensland part of the sedimentary Clarence-Moreton Basin, Australia. It contributes to the baseline hydrogeological understanding by identifying the primary groundwater flow pattern, water-level response to climate extremes, and the resulting dynamics of surface-water/groundwater interaction. Groundwater-level measurements from thousands of bores over several decades were analysed using Kriging and nonparametric trend analysis, together with a newly developed three-dimensional geological model. Groundwater-level contours suggest that groundwater flow in the shallow aquifers shows local variations in the close vicinity of streams, notwithstanding general conformance with topographic relief. The trend analysis reveals that climate variability can be quickly reflected in the shallow aquifers of the Clarence-Moreton Basin although the alluvial aquifers have a quicker rainfall response than the sedimentary bedrock formations. The Lockyer Valley alluvium represents the most sensitively responding alluvium in the area, with the highest declining (-0.7 m/year) and ascending (2.1 m/year) Sen's slope rates during and after the drought period, respectively. Different surface-water/groundwater interaction characteristics were observed in different catchments by studying groundwater-level fluctuations along hydrogeologic cross-sections. The findings of this study lay a foundation for future water-resource management in the study area.

Extensive Liquid Meltwater Storage in Firn Within the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Forster, Richard R.; Box, Jason E.; vandenBroeke, Michael R.; Miege, Clement; Burgess, Evan W.; vanAngelen, Jan H.; Lenaerts, Jan T. M.; Koenig, Lora S.; Paden, John; Lewis, Cameron;

Numerical simulation of groundwater artificial recharge in a semiarid-climate basin of northwest Mexico, case study the Guadalupe Valley Aquifer, Baja California

NASA Astrophysics Data System (ADS)

Campos-Gaytan, J. R.; Herrera-Oliva, C. S.

2013-05-01

In this study was analyzed through a regional groundwater flow model the effects on groundwater levels caused by the application of different future groundwater management scenarios (2007-2025) at the Guadalupe Valley, in Baja California, Mexico. Among these studied alternatives are those scenarios designed in order to evaluate the possible effects generated for the groundwater artificial recharge in order to satisfy a future water demand with an extraction volume considered as sustainable. The State of Baja California has been subject to an increment of the agricultural, urban and industrials activities, implicating a growing water-demand. However, the State is characterized by its semiarid-climate with low surface water availability; therefore, has resulted in an extensive use of groundwater in local aquifer. Water level measurements indicate there has been a decline in water levels in the Guadalupe Valley for the past 30 years. The Guadalupe Valley aquifer represents one the major sources of water supply in Ensenada region. It supplies about 25% of the water distributed by the public water supplier at the city of Ensenada and in addition constitutes the main water resource for the local wine industries. Artificially recharging the groundwater system is one water resource option available to the study zone, in response to increasing water demand. The existing water supply system for the Guadalupe Valley and the city of Ensenada is limited since water use demand periods in 5 to 10 years or less will require the construction of additional facilities. To prepare for this short-term demand, one option available to water managers is to bring up to approximately 3.0 Mm3/year of treated water of the city of Ensenada into the valley during the low-demand winter months, artificially recharge the groundwater system, and withdraw the water to meet the summer demands. A 2- Dimensional groundwater flow was used to evaluate the effects of the groundwater artificial recharge. Artificial recharge is feasible and is one water resource technique available to meet an increasing water demand; therefore, the final objective was to estimate the response of the groundwater system to the possible development of a system for artificial recharge of the aquifer. Based on the analysis of the groundwater management alternatives it was determined a groundwater withdrawal which ensures a sustainable management of the aquifer, in order to maintain a sustainable extraction volume and to reduce the water table depletion.

Planning for community resilience to future United States ...

EPA Pesticide Factsheets

Costs of repairing and expanding aging infrastructure and competing demands for water from other sectors such as industry and agriculture are stretching water managers’ abilities to meet essential domestic drinking water needs for future generations. Using Bayesian statistical modeling on past and present water use, we project domestic water demand in the context of four climate scenarios developed by the Intergovernmental Panel on Climate Change as part of the their Special Report on Emission Scenarios (SRES). We compare 2010 demand to projections of domestic water demand for the years 2030, 2060 and 2090 for the four SRES scenarios. Results indicate that the number of counties exceeding fifty percent or greater demand over 2010 levels increases through 2090 for two of the scenarios and plateaus around 2050 for the other two. Counties experiencing the largest increases in water demand are concentrated in the states of California, Texas, and isolated portions of the Mid-West, Southeast, and Mid-Atlantic. Closer examination of the spatial distribution of high demand counties reveals that they are typically found near or adjacent to metropolitan centers, potentially placing greater stress on already taxed systems. Identifying these counties allows for targeted adaptive management and policies, economic incentives, and legislation to be focused towards locations that are potentially the most vulnerable. We describe a new approach for projecting water demand into

Simulation of the effects of Devils Lake outlet alternatives on future lake levels and water quality in the Sheyenne River and Red River of the North

USGS Publications Warehouse

Vecchia, Aldo V.

2011-01-01

All of the outlet scenarios are effective for drawing the lake down in future years, but the more restrictive downstream constraint results in slower drawdown compared with the less restrictive constraint. For the baseline condition, the chance the lake would be above 1,450.0 feet is 99 percent in 2015 and 38 percent in 2030. For the outlet scenarios w

Politics of innovation in multi-level water governance systems

NASA Astrophysics Data System (ADS)

Daniell, Katherine A.; Coombes, Peter J.; White, Ian

2014-11-01

Innovations are being proposed in many countries in order to support change towards more sustainable and water secure futures. However, the extent to which they can be implemented is subject to complex politics and powerful coalitions across multi-level governance systems and scales of interest. Exactly how innovation uptake can be best facilitated or blocked in these complex systems is thus a matter of important practical and research interest in water cycle management. From intervention research studies in Australia, China and Bulgaria, this paper seeks to describe and analyse the behind-the-scenes struggles and coalition-building that occurs between water utility providers, private companies, experts, communities and all levels of government in an effort to support or block specific innovations. The research findings suggest that in order to ensure successful passage of the proposed innovations, champions for it are required from at least two administrative levels, including one with innovation implementation capacity, as part of a larger supportive coalition. Higher governance levels can play an important enabling role in facilitating the passage of certain types of innovations that may be in competition with currently entrenched systems of water management. Due to a range of natural biases, experts on certain innovations and disciplines may form part of supporting or blocking coalitions but their evaluations of worth for water system sustainability and security are likely to be subject to competing claims based on different values and expertise, so may not necessarily be of use in resolving questions of "best courses of action". This remains a political values-based decision to be negotiated through the receiving multi-level water governance system.

Towards saving freshwater: halophytes as unconventional feedstuffs in livestock feed: a review.

PubMed

Abd El-Hack, Mohamed E; Samak, Dalia H; Noreldin, Ahmed E; Arif, Muhammad; Yaqoob, Hilal S; Swelum, Ayman A

2018-04-26

Water represents 71% of all earth area and about 97% of this water is salty water. So, only 3% of the overall world water quantity is freshwater. Human can benefit only from 1% of this water and the remaining 2% freeze at both poles of earth. Therefore, it is important to preserve the freshwater through increasing the plants consuming salty water. The future prosperity of feed resources in arid and semi-arid countries depends on economic use of alternative resources that have been marginalized for long periods of time, such as halophytic plants, which are one such potential future resource. Halophyte plants can grow in high salinity water and soil and to some extent during drought. The growth of these plants depends on the contact of the salted water with plant roots as in semi-desert saline water, mangrove swamps, marshes, and seashores. Halophyte plants need high levels of sodium chloride in the soil water for growth, and the soil water must also contain high levels of salts, as sodium hydroxide or magnesium sulfate. There are many uses for halophyte plants, including feed for animals, vegetables, drugs, sand dune stabilizers, wind shelter, soil cover, wetland cultivation, laundry detergents, and paper production. This paper will focus on the use of halophytes as a feed additive for animals. In spite of the good nutritional value of halophytes, some anti-nutritional factors as nitrates, nitrite complexes, tannins, glycosides, phenolic compounds, saponins, oxalates, and alkaloids may be present in some of them. The presence of such anti-nutritional agents makes halophytes unpalatable to animals, which tends to reduce feed intake and nutrient use. Therefore, the negative effects of these plants on animal performance are the only objection against using halophytes in animal feed diets. This review article highlights the beneficial impact of considering halophytes in animal feeding on saving freshwater and illustrates its nutritive value for livestock from different aspects.

Reactivation of Kamb Ice Stream tributaries triggers century-scale reorganization of Siple Coast ice flow in West Antarctica

DOE PAGES

Bougamont, M.; Christoffersen, P.; Price, S. F.; ...

2015-10-21

Ongoing, centennial-scale flow variability within the Ross ice streams of West Antarctica suggests that the present-day positive mass balance in this region may reverse in the future. Here we use a three-dimensional ice sheet model to simulate ice flow in this region over 250 years. The flow responds to changing basal properties, as a subglacial till layer interacts with water transported in an active subglacial hydrological system. We show that a persistent weak bed beneath the tributaries of the dormant Kamb Ice Stream is a source of internal ice flow instability, which reorganizes all ice streams in this region, leadingmore » to a reduced (positive) mass balance within decades and a net loss of ice within two centuries. This hitherto unaccounted for flow variability could raise sea level by 5 mm this century. Furthermore, better constraints on future sea level change from this region will require improved estimates of geothermal heat flux and subglacial water transport.« less

Global water resources affected by human interventions and climate change.

PubMed

Haddeland, Ingjerd; Heinke, Jens; Biemans, Hester; Eisner, Stephanie; Flörke, Martina; Hanasaki, Naota; Konzmann, Markus; Ludwig, Fulco; Masaki, Yoshimitsu; Schewe, Jacob; Stacke, Tobias; Tessler, Zachary D; Wada, Yoshihide; Wisser, Dominik

2014-03-04

Humans directly change the dynamics of the water cycle through dams constructed for water storage, and through water withdrawals for industrial, agricultural, or domestic purposes. Climate change is expected to additionally affect water supply and demand. Here, analyses of climate change and direct human impacts on the terrestrial water cycle are presented and compared using a multimodel approach. Seven global hydrological models have been forced with multiple climate projections, and with and without taking into account impacts of human interventions such as dams and water withdrawals on the hydrological cycle. Model results are analyzed for different levels of global warming, allowing for analyses in line with temperature targets for climate change mitigation. The results indicate that direct human impacts on the water cycle in some regions, e.g., parts of Asia and in the western United States, are of the same order of magnitude, or even exceed impacts to be expected for moderate levels of global warming (+2 K). Despite some spread in model projections, irrigation water consumption is generally projected to increase with higher global mean temperatures. Irrigation water scarcity is particularly large in parts of southern and eastern Asia, and is expected to become even larger in the future.

Global water resources affected by human interventions and climate change

PubMed Central

Haddeland, Ingjerd; Heinke, Jens; Biemans, Hester; Eisner, Stephanie; Flörke, Martina; Hanasaki, Naota; Konzmann, Markus; Ludwig, Fulco; Masaki, Yoshimitsu; Schewe, Jacob; Stacke, Tobias; Tessler, Zachary D.; Wada, Yoshihide; Wisser, Dominik

2014-01-01

Humans directly change the dynamics of the water cycle through dams constructed for water storage, and through water withdrawals for industrial, agricultural, or domestic purposes. Climate change is expected to additionally affect water supply and demand. Here, analyses of climate change and direct human impacts on the terrestrial water cycle are presented and compared using a multimodel approach. Seven global hydrological models have been forced with multiple climate projections, and with and without taking into account impacts of human interventions such as dams and water withdrawals on the hydrological cycle. Model results are analyzed for different levels of global warming, allowing for analyses in line with temperature targets for climate change mitigation. The results indicate that direct human impacts on the water cycle in some regions, e.g., parts of Asia and in the western United States, are of the same order of magnitude, or even exceed impacts to be expected for moderate levels of global warming (+2 K). Despite some spread in model projections, irrigation water consumption is generally projected to increase with higher global mean temperatures. Irrigation water scarcity is particularly large in parts of southern and eastern Asia, and is expected to become even larger in the future. PMID:24344275

Modification of land-atmosphere interactions by CO2 effects

NASA Astrophysics Data System (ADS)

Lemordant, Leo; Gentine, Pierre

2017-04-01

Plant stomata couple the energy, water and carbon cycles. Increased CO2 modifies the seasonality of the water cycle through stomatal regulation and increased leaf area. As a result, the water saved during the growing season through higher water use efficiency mitigates summer dryness and the impact of potential heat waves. Land-atmosphere interactions and CO2 fertilization together synergistically contribute to increased summer transpiration. This, in turn, alters the surface energy budget and decreases sensible heat flux, mitigating air temperature rise. Accurate representation of the response to higher CO2 levels, and of the coupling between the carbon and water cycles are therefore critical to forecasting seasonal climate, water cycle dynamics and to enhance the accuracy of extreme event prediction under future climate.

The Development of a Real Time Surface Water Flow Model to Protect Public Water Intakes in West Virginia

NASA Astrophysics Data System (ADS)

Zegre, N.; Strager, M.

2015-12-01

In January of 2014 West Virginia experienced a chemical spill upstream of a public water intake on the Elk River near Charleston, West Virginia that made the water unusable for 300,000 people for weeks. In response to this disaster, state officials enacted legislation to protect the future public water intake locations by requiring the delineation of zones of critical concern that extend a five hour travel time above the intakes. Each zone is defined by the travel time and buffered along the river mainstem and tributary locations to identify future potential threats to the water supply. While this approach helps to identify potential problems before they occur, the need existed to be able to respond to a spill with information regarding the real travel time of a spill to an intake with consideration of actual stream flow at the time of the spill. This study developed a real time surface flow model to protect the public water intakes using both regional and seasonal variables. Bayesian statistical inference enabled confidence levels to be placed on flow estimates and used to show the probability for the time steps as water approached an public water intake. The flow model has been incorporated into both a smartphone app and web-based tool for better emergency response and management of water resources throughout the state.

Effectiveness and Tradeoffs between Portfolios of Adaptation Strategies Addressing Future Climate and Socioeconomic Uncertainties in California's Central Valley

NASA Astrophysics Data System (ADS)

Tansey, M. K.; Van Lienden, B.; Das, T.; Munevar, A.; Young, C. A.; Flores-Lopez, F.; Huntington, J. L.

2013-12-01

The Central Valley of California is one of the major agricultural areas in the United States. The Central Valley Project (CVP) is operated by the Bureau of Reclamation to serve multiple purposes including generating approximately 4.3 million gigawatt hours of hydropower and providing, on average, 5 million acre-feet of water per year to irrigate approximately 3 million acres of land in the Sacramento, San Joaquin, and Tulare Lake basins, 600,000 acre-feet per year of water for urban users, and 800,000 acre-feet of annual supplies for environmental purposes. The development of effective adaptation and mitigation strategies requires assessing multiple risks including potential climate changes as well as uncertainties in future socioeconomic conditions. In this study, a scenario-based analytical approach was employed by combining three potential 21st century socioeconomic futures with six representative climate and sea level change projections developed using a transient hybrid delta ensemble method from an archive of 112 bias corrected spatially downscaled CMIP3 global climate model simulations to form 18 future socioeconomic-climate scenarios. To better simulate the effects of climate changes on agricultural water demands, analyses of historical agricultural meteorological station records were employed to develop estimates of future changes in solar radiation and atmospheric humidity from the GCM simulated temperature and precipitation. Projected changes in atmospheric carbon dioxide were computed directly by weighting SRES emissions scenarios included in each representative climate projection. These results were used as inputs to a calibrated crop water use, growth and yield model to simulate the effects of climate changes on the evapotranspiration and yields of major crops grown in the Central Valley. Existing hydrologic, reservoir operations, water quality, hydropower, greenhouse gas (GHG) emissions and both urban and agricultural economic models were integrated into a suite of decision support tools to assess the impacts of future socioeconomic-climate uncertainties on key performance metrics for the CVP, State Water Project and other Central Valley water management systems under current regulatory requirements. Four thematic portfolios consisting of regional and local adaptation strategies including changes in reservoir operations, increased water conservation, storage and conveyance were developed and simulated to evaluate their potential effectiveness in meeting delivery reliability, water quality, environmental, hydropower, GHG, urban and agricultural economic performance criteria. The results indicate that the portfolios exhibit a considerable range of effectiveness depending on the socioeconomic-climate scenario. For most criteria, the portfolios were more sensitive to climate projections than socioeconomic assumptions. However, the results demonstrate that important tradeoffs occur between portfolios depending on the performance criteria considered.

Addressing Climate Change in Long-Term Water Planning Using Robust Decisionmaking

NASA Astrophysics Data System (ADS)

Groves, D. G.; Lempert, R.

2008-12-01

Addressing climate change in long-term natural resource planning is difficult because future management conditions are deeply uncertain and the range of possible adaptation options are so extensive. These conditions pose challenges to standard optimization decision-support techniques. This talk will describe a methodology called Robust Decisionmaking (RDM) that can complement more traditional analytic approaches by utilizing screening-level water management models to evaluate large numbers of strategies against a wide range of plausible future scenarios. The presentation will describe a recent application of the methodology to evaluate climate adaptation strategies for the Inland Empire Utilities Agency in Southern California. This project found that RDM can provide a useful way for addressing climate change uncertainty and identify robust adaptation strategies.

Assessing hydrological effects of human interventions on coastal systems: numerical applications to the Venice Lagoon

NASA Astrophysics Data System (ADS)

Ferrarin, C.; Ghezzo, M.; Umgiesser, G.; Tagliapietra, D.; Camatti, E.; Zaggia, L.; Sarretta, A.

2013-05-01

The hydrological consequences of historical, contemporary and future human activities on a coastal system were investigated by means of numerical models. The changes in the morphology of the Lagoon of Venice during the last century result from the sedimentological response to the combined effects of human interventions on the environment and global changes. This study focuses on changes from 1927 to 2012 and includes the changes planned for the protection of the city of Venice from storm surges and exceptional tides under future sea level rise scenarios. The application of a hydrodynamic model allowed for the analysis of the morphological effects on the lagoon circulation, the interaction with the sea and the internal mixing processes. The absolute values of the exchange between the lagoon and sea increased from 1927 to 2002 (from 3900 to 4600 m3 s-1), while the daily fraction of lagoon water volume exchanged decreased. At the same time, the flattening of the lagoon and loss of morphological heterogeneity enhanced the internal mixing processes driven by the tide and wind, reducing thus the overall water renewal time from 11.9 days in 1927 to 10.8 days in 2002. Morphological changes during the last decade reduced the water exchange through the inlets and induced an increase of the basin-wide water renewal time of 0.5 day. In the future, Venice Lagoon will evolve to a more restricted environment due to sea level rise, which increases the lagoon volume, and periodical closure of the lagoon from the sea during flooding events, which reduces the communication with the open sea. Therefore, the flushing capacity of the lagoon will decrease considerably, especially in its central part. Furthermore, some considerations on the impact of the hydromorphological changes on the ecological dynamics are proposed.

Potential for using the Upper Coachella Valley ground-water basin, California, for storage of artificially recharged water

USGS Publications Warehouse

Mallory, Michael J.; Swain, Lindsay A.; Tyley, Stephen J.

1980-01-01

This report presents a preliminary evaluation of the geohydrologic factors affecting storage of water by artificial recharge in the upper Coachella Valley, Calif. The ground-water basin of the upper Coachella Valley seems to be geologically suitable for large-scale artificial recharge. A minimum of 900 ,000 acre-feet of water could probably be stored in the basin without raising basinwide water levels above those that existed in 1945. Preliminary tests indicate that a long-term artificial recharge rate of 5 feet per day may be feasible for spreading grounds in the basin if such factors as sediment and bacterial clogging can be controlled. The California Department of Water Resources, through the Future Water Supply Program, is investigating the use of ground-water basins for storage of State Water Project water in order to help meet maximum annual entitlements to water project contractors. (USGS)

Simulated effects of projected withdrawals from the Wenonah-Mount Laurel Aquifer on ground-water levels in the Camden, New Jersey, area and vicinity

USGS Publications Warehouse

Navoy, A.S.

1994-01-01

The Wenonah-Mount Laurel aquifer is being considered as a potential source of future water supply for the Camden, New Jersey, area. The deeper Potomac- Raritan-Magothy aquifer system is currently the major major source of water supply for the area, but its use may be curtailed or reduced by 35 percent of 1983 withdrawals through its designation by the New Jersey Department of Environmental Protection and Energy as "Water Supply Critical Area#2." Withdrawals from the Wenonah-Mount Laurel aquifer currently (1989) total about 7 million gallons per day. The anticipated use of this aquifer by communities with access to it, as an alternative supply, could increase to more than 14 million gallons per day by 2020. If the communities of Clayton and Glassboro decrease their withdrawals from the Potomac-Raritan-Magothy aquifer system by 50 percent or cease them entirely because of their proximity to saline water, the use of Wenonah-Mount Laurel aquifer could increase to greater than 15 million gallons per day by 2020. Simulation of the ground-water system indicates that the projected increase in withdrawals will cause cones of depression in the potentiometric surface of the Wenonah-Mount Laurel aquifer in the Camden metro- politan area by 2020 that extend to depths ranging from 10 feet above sea level to 60 feet below sea level. This represents a secline of about 40 to 100 feet thr 1990 conditions. Withdrawals in northeastern Burlington County will cause a large cone of depression that, by 2020, will extend to depths of about 220 feet below sea level, represent- ing a decline of about 140 feet from 1990 conditions. Simulation results indicate that water levels in the Wenonah-Mount Laurel aquifer near the Salem Nuclear Power Plant are somewhat insensitive to withdrawals elsewhere in the aquifer. In some areas, especially in Burlington County, the cones of depression have developed in proximity to the aquifer-outcrop area and could induce infiltration from streams crossing the outcrop. Because of the hydraulic connection to adjacent aquifers, future management plans need to be developed in a compre- hensive manner with regard to all aquifers. Further study of the aquifer in Salem County could provide additional information on the hydraulic connection to Delaware Bay and the potential for saltwater intrusion.

Flood return level analysis of Peaks over Threshold series under changing climate

NASA Astrophysics Data System (ADS)

Li, L.; Xiong, L.; Hu, T.; Xu, C. Y.; Guo, S.

2016-12-01

Obtaining insights into future flood estimation is of great significance for water planning and management. Traditional flood return level analysis with the stationarity assumption has been challenged by changing environments. A method that takes into consideration the nonstationarity context has been extended to derive flood return levels for Peaks over Threshold (POT) series. With application to POT series, a Poisson distribution is normally assumed to describe the arrival rate of exceedance events, but this distribution assumption has at times been reported as invalid. The Negative Binomial (NB) distribution is therefore proposed as an alternative to the Poisson distribution assumption. Flood return levels were extrapolated in nonstationarity context for the POT series of the Weihe basin, China under future climate scenarios. The results show that the flood return levels estimated under nonstationarity can be different with an assumption of Poisson and NB distribution, respectively. The difference is found to be related to the threshold value of POT series. The study indicates the importance of distribution selection in flood return level analysis under nonstationarity and provides a reference on the impact of climate change on flood estimation in the Weihe basin for the future.

Agricultural irrigated land-use inventory for Osceola County, Florida, October 2013-April 2014

USGS Publications Warehouse

Marella, Richard L.; Dixon, Joann F.

2014-01-01

A detailed inventory of irrigated crop acreage is not available at the level of resolution needed to increase the accuracy of current water-use estimates or to project future water demands in many Florida counties. This report provides a detailed digital map and summary of irrigated areas within Osceola County for the agricultural growing period October 2013–April 2014. The irrigated areas were first delineated using land-use data and satellite imagery and then field verified between February and April 2014. Selected attribute data were collected for the irrigated areas, including crop type, primary water source, and type of irrigation system. Results indicate that an estimated 27,450 acres were irrigated during the study period. This includes 4,370 acres of vegetables, 10,970 acres of orchard crops, 1,620 acres of field crops, and 10,490 acres of ornamentals and grasses. Specifically, irrigated acreage included citrus (10,860 acres), sod (5,640 acres), pasture (4,580 acres), and potatoes (3,320 acres). Overall, groundwater was used to irrigate 18,350 acres (67 percent of the total acreage), and surface water was used to irrigate the remaining 9,100 acres (33 percent). Microirrigation systems accounted for 45 percent of the total acreage irrigated, flood systems 30 percent, and sprinkler systems the remaining 25 percent. An accurate, detailed, spatially referenced, and field-verified inventory of irrigated crop acreage can be used to assist resource managers making current and future county-level water-use estimates in Osceola County.

Cyprinodon diabolis: prospects for an endangered desert pupfish in a changing climate

NASA Astrophysics Data System (ADS)

Hausner, M. B.; Wilson, K. P.; Gaines, D. B.; Suarez, F. I.; Tyler, S. W.

2013-12-01

A small groundwater-fed ecosystem in the Mojave Desert of the southwestern United States, Devils Hole is home to the only extant population of the Devils Hole pupfish (Cyprinodon diabolis). The critically endangered population of these fish entered a heretofore unexplained decline in the mid-1990s. Successful reproduction in Cyprinodon spp. is influenced by both water temperature and dissolved oxygen content, and the annual recruitment of C. diabolis depends on the coincidence of annual temperature cycles and seasonal changes in the ecosystem's food web. Recent climate change in the Mojave Desert is already sufficient to increase water temperatures more than 0.1 °C. Understanding the future impacts of climate on the ecosystem is critical to management and conservation efforts. In this study, we employ computational fluid dynamics to consider the ecosystem's physical response to projected climate scenarios. Using an energy-based model driven by a range of climate (air temperatures) and management (water levels) scenarios, we simulate water temperatures on the critical shallow shelf that comprises the optimum spawning habitat in the ecosystem. Results show that increasing air temperatures shift the timing of the thermal conditions conducive to spawning and the ecosystem's food web, and that the brief period each spring during which both aspects are suitable for recruitment will likely become shorter in the future. Simulations also show that the impact of air temperature on water temperature is much less for scenarios in which the water level is higher, pointing toward one potential strategy for mitigating the ecological effects of the changing climate.

Preliminary investigation of the effects of sea-level rise on groundwater levels in New Haven, Connecticut

USGS Publications Warehouse

Bjerklie, David M.; Mullaney, John R.; Stone, Janet R.; Skinner, Brian J.; Ramlow, Matthew A.

2012-01-01

Global sea level rose about 0.56 feet (ft) (170 millimeters (mm)) during the 20th century. Since the 1960s, sea level has risen at Bridgeport, Connecticut, about 0.38 ft (115 mm), at a rate of 0.008 ft (2.56 mm + or - 0.58 mm) per year. With regional subsidence, and with predicted global climate change, sea level is expected to continue to rise along the northeast coast of the United States through the 21st century. Increasing sea levels will cause groundwater levels in coastal areas to rise in order to adjust to the new conditions. Some regional climate models predict wetter climate in the northeastern United States under some scenarios. Scenarios for the resulting higher groundwater levels have the potential to inundate underground infrastructure in lowlying coastal cities. New Haven is a coastal city in Connecticut surrounded and bisected by tidally affected waters. Monitoring of water levels in wells in New Haven from August 2009 to July 2010 indicates the complex effects of urban influence on groundwater levels. The response of groundwater levels to recharge and season varied considerably from well to well. Groundwater temperatures varied seasonally, but were warmer than what was typical for Connecticut, and they seem to reflect the influence of the urban setting, including the effects of conduits for underground utilities. Specific conductance was elevated in many of the wells, indicating the influence of urban activities or seawater in Long Island Sound. A preliminary steady-state model of groundwater flow for part of New Haven was constructed using MODFLOW to simulate current groundwater levels (2009-2010) and future groundwater levels based on scenarios with a rise of 3 ft (0.91 meters (m)) in sea level, which is predicted for the end of the 21st century. An additional simulation was run assuming a 3-ft rise in sea level combined with a 12-percent increase in groundwater recharge. The model was constructed from existing hydrogeologic information for the New Haven area and from new information on groundwater levels collected during October 2009-June 2010. For the scenario with a 3-ft rise in sea level and no increase in recharge, simulated groundwater levels near the coast rose 3 ft; this increased water level tapered off toward a discharge area at the only nontidal stream in the study area. Simulated stream discharge increased at the nontidal stream because of the increased gradient. Although groundwater levels rose, the simulated difference between the groundwater levels in the aquifer and the increased sea level declined, indicating that the depth to the interface between freshwater and saltwater may possibly decline. Simulated water levels were affected by rise in sea level even in areas where the water table was at 17-24 ft (5.2-7.3 m) above current (2011) sea level. For the scenario with increased recharge, simulated groundwater levels were as much as an additional foot higher at some locations in the study area. The results of this preliminary investigation indicate that groundwater levels in coastal areas can be expected to rise and may rise higher if groundwater recharge also increases. This finding has implications for the disposal of stormwater through infiltration, a low-impact development practice designed to improve water quality and reduce overland peak discharge. Other implications include increased risk of basement flooding and increased groundwater seepage into underground sewer pipes and utility corridors in some areas. These implications will present engineering challenges to New Haven and Yale University. The preliminary model developed for this study can be the starting point for further simulation of future alternative scenarios for sea-level rise and recharge. Further simulations could identify those areas of New Haven where infrastructure may be at greatest risk from rising levels of groundwater. The simulations described in this report have limitations due to the preliminary scope of the work. Approaches to improve simulations include but are not limited to incorporating: * The variable density of seawater into the model in order to understand the current and future location of the interface between freshwater and saltwater; * Collection of additional data in order to better resolve temporal and spatial patterns in water levels in the aquifer; * Improved estimates of recharge through direct and indirect measurements of freshwater discharge from the study area; and * Transient simulations for greater understanding of the amount of time required for water levels and the position of the interface between freshwater and saltwater to adjust to changes in sea level and recharge.

The effectiveness of recent water restriction policies on single-family water use in Los Angeles, California

NASA Astrophysics Data System (ADS)

Mini, C.; Hogue, T. S.; Pincetl, S.

2013-12-01

Residential water consumption represents the largest urban water consumer category and is projected to have significant increase over the next 20 years in Los Angeles, California. Successive severe droughts have occurred in Los Angeles over the past 30 years leading to the implementation of emergency water conservation measures that include limiting the time and frequency of urban irrigation as well as applying shortage year water rates. Reliance on imported water sources dramatically increased during the past drought periods, which questions the reliability of future water supply. The objectives of the current study include quantifying the impact of past water restrictions on single-family residential water use in single-family areas in Los Angeles. Three phases of water restrictions were implemented during the 2007-2010 drought period to reduce water consumption: voluntary restrictions during fiscal year 2007-2008, mandatory outdoor use restrictions in fiscal year 2008-2009, and more stringent mandatory restrictions limiting the frequency of irrigation coupled with a water rate increase in fiscal year 2009-2010. Los Angeles Department of Water and Power (LADWP) monthly individual water use records from 2000 to 2010 were aggregated at the block level in the San Fernando Valley. The effectiveness of the three water restrictions phases was analyzed through a linear regression model developed over 2000-2007 with single-family water use as the dependent variable, climate, and economic variables as the predictors at the block level. Predicted water use during the 2007-2010 period was estimated using results from the statistical model and compared with actual water use to calculate the amount of water savings due to the restrictions. The comparison of the impact of water restrictions on single-family water use reveals that the more stringent mandatory water restrictions provided a higher and statistically significant decrease in water use. Single-family water consumption decreased by 20% on average over the study area during the 2009-2010 fiscal year, compared to a 2% increase during the voluntary restriction period and a 9% decrease during the 2008-2009 fiscal year. Mandatory restrictions proved to be more effective than voluntary restrictions as solutions to reduce water use during drought periods. Our results provide key information on potential implementation of future water policies under difficult economic conditions and help identify successful targeted conservation measures that can be permanently established.

A Screening-Level Approach for Comparing Risks Affecting Aquatic Ecosystem Services over Socio-Environmental Gradients

NASA Astrophysics Data System (ADS)

Harmon, T. C.; Conde, D.; Villamizar, S. R.; Reid, B.; Escobar, J.; Rusak, J.; Hoyos, N.; Scordo, F.; Perillo, G. M.; Piccolo, M. C.; Zilio, M.; Velez, M.

2015-12-01

Assessing risks to aquatic ecosystems services (ES) is challenging and time-consuming, and effective strategies for prioritizing more detailed assessment efforts are needed. We propose a screening-level risk analysis (SRA) approach that scales ES risk using socioeconomic and environmental indices to capture anthropic and climatic pressures, as well as the capacity for institutional responses to those pressures. The method considers ES within a watershed context, and uses expert input to prioritize key services and the associated pressures that threaten them. The SRA approach focuses on estimating ES risk affect factors, which are the sum of the intensity factors for all hazards or pressures affecting the ES. We estimate the pressure intensity factors in a novel manner, basing them on the nation's (i) human development (proxied by Inequality-adjusted Human Development Index, IHDI), (ii) environmental regulatory and monitoring state (Environmental Performance Index, EPI) and (iii) the current level of water stress in the watershed (baseline water stress, BWS). Anthropic intensity factors for future conditions are derived from the baseline values based on the nation's 10-year trend in IHDI and EPI; ES risks in nations with stronger records of change are rewarded more/penalized less in estimates for good/poor future management scenarios. Future climatic intensity factors are tied to water stress estimates based on two general circulation model (GCM) outcomes. We demonstrate the method for an international array of six sites representing a wide range of socio-environmental settings. The outcomes illustrate novel consequences of the scaling scheme. Risk affect factors may be greater in a highly developed region under intense climatic pressure, or in less well-developed regions due to human factors (e.g., poor environmental records). As a screening-level tool, the SRA approach offers considerable promise for ES risk comparisons among watersheds and regions so that detailed assessment, management and mitigation efforts can be effectively prioritized.

The impact of future sea-level rise on the global tides

NASA Astrophysics Data System (ADS)

Pickering, M. D.; Horsburgh, K. J.; Blundell, J. R.; Hirschi, J. J.-M.; Nicholls, R. J.; Verlaan, M.; Wells, N. C.

2017-06-01

Tides are a key component in coastal extreme water levels. Possible changes in the tides caused by mean sea-level rise (SLR) are therefore of importance in the analysis of coastal flooding, as well as many other applications. We investigate the effect of future SLR on the tides globally using a fully global forward tidal model: OTISmpi. Statistical comparisons of the modelled and observed tidal solutions demonstrate the skill of the refined model setup with no reliance on data assimilation. We simulate the response of the four primary tidal constituents to various SLR scenarios. Particular attention is paid to future changes at the largest 136 coastal cities, where changes in water level would have the greatest impact. Spatially uniform SLR scenarios ranging from 0.5 to 10 m with fixed coastlines show that the tidal amplitudes in shelf seas globally respond strongly to SLR with spatially coherent areas of increase and decrease. Changes in the M2 and S2 constituents occur globally in most shelf seas, whereas changes in K1 and O1 are confined to Asian shelves. With higher SLR tidal changes are often not proportional to the SLR imposed and larger portions of mean high water (MHW) changes are above proportional. Changes in MHW exceed ±10% of the SLR at 10% of coastal cities. SLR scenarios allowing for coastal recession tend increasingly to result in a reduction in tidal range. The fact that the fixed and recession shoreline scenarios result mainly in changes of opposing sign is explained by the effect of the perturbations on the natural period of oscillation of the basin. Our results suggest that coastal management strategies could influence the sign of the tidal amplitude change. The effect of a spatially varying SLR, in this case fingerprints of the initial elastic response to ice mass loss, modestly alters the tidal response with the largest differences at high latitudes.

Simulation and assessment of groundwater flow and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2003 through 2013: Chapter B of Water levels and groundwater and surface-water exchanges in lakes of the northeast Twin Cities Metropolitan Area, Minnesota, 2002 through 2015

USGS Publications Warehouse

Jones, Perry M.; Roth, Jason L.; Trost, Jared J.; Christenson, Catherine A.; Diekoff, Aliesha L.; Erickson, Melinda L.

2017-09-05

Water levels during 2003 through 2013 were less than mean water levels for the period 1925–2013 for several lakes in the northeast Twin Cities Metropolitan Area in Minnesota. Previous periods of low lake-water levels generally were correlated with periods with less than mean precipitation. Increases in groundwater withdrawals and land-use changes have brought into question whether or not recent (2003–13) lake-water-level declines are solely caused by decreases in precipitation. A thorough understanding of groundwater and surface-water exchanges was needed to assess the effect of water-management decisions on lake-water levels. To address this need, the U.S. Geological Survey, in cooperation with the Metropolitan Council and the Minnesota Department of Health, developed and calibrated a three-dimensional, steady-state groundwater-flow model representing 2003–13 mean hydrologic conditions to assess groundwater and lake-water exchanges, and the effects of groundwater withdrawals and precipitation on water levels of 96 lakes in the northeast Twin Cities Metropolitan Area.Lake-water budgets for the calibrated groundwater-flow model indicated that groundwater is flowing into lakes in the northeast Twin Cities Metropolitan Area and lakes are providing water to underlying aquifers. Lake-water outflow to the simulated groundwater system was a major outflow component for Big Marine Lake, Lake Elmo, Snail Lake, and White Bear Lake, accounting for 45 to 64 percent of the total outflows from the lakes. Evaporation and transpiration from the lake surface ranged from 19 to 52 percent of the total outflow from the four lakes. Groundwater withdrawals and precipitation were varied from the 2003‒13 mean values used in the calibrated model (30-percent changes in groundwater withdrawals and 5-percent changes in precipitation) for hypothetical scenarios to assess the effects of groundwater withdrawals and precipitation on water budgets and levels in Big Marine Lake, Snail Lake, and White Bear Lake. Simulated lake-water levels and budgets for Snail Lake and White Bear Lake were affected by 30-percent changes in groundwater withdrawals and 5-percent changes in precipitation in the area, whereas the water level in Big Marine Lake was mainly affected by 5-percent precipitation changes. The effects of groundwater withdrawals on the lake-water levels depend on the number of wells and amount of withdrawals from wells near the lakes. Although lake-water levels are sensitive to precipitation changes, increases in groundwater withdrawals during dry periods exacerbate lake-water level declines. The calibrated, groundwater-flow model is a tool that water-resources managers can use to address future water management issues in the northeast Twin Cities Metropolitan Area.

A National Energy-Water System Assessment Framework (NEWS): Synopsis of Stage 1 Research Strategy and Results

NASA Astrophysics Data System (ADS)

Vorosmarty, C. J.; Miara, A.; Macknick, J.; Newmark, R. L.; Cohen, S.; Sun, Y.; Tidwell, V. C.; Corsi, F.; Melillo, J. M.; Fekete, B. M.; Proussevitch, A. A.; Glidden, S.; Suh, S.

2017-12-01

The focus of this talk is on climate adaptation and the reliability of power supply infrastructure when viewed through the lens of strategic water issues. Power supply is critically dependent upon water resources, particularly to cool thermoelectric plants, making the sector particularly sensitive to any shifts in the geography or seasonality of water supply. We report on results from an NSF-Funded Water Sustainability and Climate effort aimed at uncovering key energy and economic system vulnerabilities. We have developed the National Energy-Water System assessment framework (NEWS) to systematically evaluate: a) the performance of the nation's electricity sector under multiple climate scenarios; b) the feasibility of alternative pathways to improve climate adaptation; and, c) the impacts of energy technology and investment tradeoffs on the economic productivity, water availability and aquatic ecosystem condition. Our project combines core engineering and geophysical models (ReEDS [Regional Energy Deployment System], TP2M [Thermoelectric Power and Thermal Pollution], and WBM [Water Balance]) through unique digital "handshake" protocols that operate across different institutions and modeling platforms. Combined system outputs are fed into a regional-to-national scale economic input/output model to evaluate economic consequences of climate constraints, technology choices, and environmental regulation. The impact assessments in NEWS are carried out through a series of climate/energy policy scenario studies to 2050. We find that despite significant climate-water impacts on individual plants, the current US power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. However, the magnitude and implications of climate-water impacts vary depending on the configuration of the future power sector. To evaluate future power supply performance, we model alternative electricity sector pathways in combination with varying climate-water conditions. Further, water-linked disruptions in electricity supply yield substantial impacts on regional economies yet system-level shocks can be attenuated through different technology mixes and infrastructure.

An Integrated Approach to Identification, Assessment and Management of Watershed-Scale Risk for Sustainable Water Use Through Reuse and Recycling

NASA Astrophysics Data System (ADS)

Hunter, C. K.; Bolster, D.; Gironas, J. A.

2014-12-01

Water resources are essential to development, not only economically but also socially, politically and ecologically. With growing demand and potentially shrinking supply, water scarcity is one of the most pressing socio-ecological problems of the 21st century. Considering implications of global change and the complexity of interrelated systems, uncertain future conditions compound problems associated with water stress, requiring hydrologic models to re-examine traditional water resource planning and management. The Copiapó water basin, located in the Atacama Desert of northern Chile exhibits a complex resource management scenario. With annual average precipitation of only 28 mm, water intensive sectors such as export agriculture, extensive mining, and a growing population have depleted the aquifeŕs reserves to near critical levels. Being that global climate change models predict a decrease in already scarce precipitation, and that growing population and economies demand will likely increase, the real future situation might be even worse than that predicted. A viable option for alleviation of water stress, water reuse and recycling has evolved through technological innovation to feasibly meet hydraulic needs with reclaimed water. For the proper application of these methods for resource management, however, stakeholders must possess tools by which to quantify hydrologic risk, understand its factors of causation, and choose between competing management scenarios and technologies so as to optimize productivity. While previous investigations have addressed similar problems, they often overlook aspects of forecasting uncertainty, proposing solutions that while accurate under specific scenarios, lack robustness to withstand future variations. Using the WEAP (Water Evaluation and Planning) platform for hydrologic modeling, this study proposes a methodology, applicable to other stressed watersheds, to quantify inherent risk in water management positions, while considering uncertainties in supply (climate change), demand (market variations), and measurement (risk definition). Applied to the Copaipó case study, this methodology proposes the solution of a 30% demand decrease within the agricultural sector through urban wastewater recycling and increased irrigation efficiency.

Vibrational spectroscopy of water in hydrated lipid multi-bilayers. II. Two-dimensional infrared and peak shift observables within different theoretical approximations.

PubMed

Gruenbaum, Scott M; Pieniazek, Piotr A; Skinner, J L

2011-10-28

In a previous report, we calculated the infrared absorption spectrum and both the isotropic and anisotropic pump-probe signals for the OD stretch of isotopically dilute water in dilauroylphosphatidylcholine (DLPC) multi-bilayers as a function of the lipid hydration level. These results were then compared to recent experimental measurements and are in generally good agreement. In this paper, we will further investigate the structure and dynamics of hydration water using molecular dynamics simulations and calculations of the two-dimensional infrared and vibrational echo peak shift observables for hydration water in DLPC membranes. These observables have not yet been measured experimentally, but future comparisons may provide insight into spectral diffusion processes and hydration water heterogeneity. We find that at low hydration levels the motion of water molecules inside the lipid membrane is significantly arrested, resulting in very slow spectral diffusion. At higher hydration levels, spectral diffusion is more rapid, but still slower than in bulk water. We also investigate the effects of several common approximations on the calculation of spectroscopic observables by computing these observables within multiple levels of theory. The impact of these approximations on the resulting spectra affects our interpretation of these measurements and reveals that, for example, the cumulant approximation, which may be valid for certain systems, is not a good approximation for a highly heterogeneous environment such as hydration water in lipid multi-bilayers.

A generic method for projecting and valuing domestic water uses, application to the Mediterranean basin at the 2050 horizon.

NASA Astrophysics Data System (ADS)

Neverre, Noémie; Dumas, Patrice

2014-05-01

The aim is to be able to assess future domestic water demands in a region with heterogeneous levels of economic development. This work offers an original combination of a quantitative projection of demands (similar to WaterGAP methodology) and an estimation of the marginal benefit of water. This method is applicable to different levels of economic development and usable for large-scale hydroeconomic modelling. The global method consists in building demand functions taking into account the impact of both the price of water and the level of equipment, proxied by economic development, on domestic water demand. Our basis is a 3-blocks inverse demand function: the first block consists of essential water requirements for food and hygiene; the second block matches intermediate needs; and the last block corresponds to additional water consumption, such as outdoor uses, which are the least valued. The volume of the first block is fixed to match recommended basic water requirements from the literature, but we assume that the volume limits of blocks 2 and 3 depend on the level of household equipment and therefore evolve with the level of GDP per capita (structural change), with a saturation. For blocks 1 and 2 we determine the value of water from elasticity, price and quantity data from the literature, using the point-extension method. For block 3, we use a hypothetical zero-cost demand and maximal demand with actual water costs to linearly interpolate the inverse demand function. These functions are calibrated on the 24 countries part of the Mediterranean basin using data from SIMEDD, and are used for the projection and valuation of domestic water demands at the 2050 horizon. They enable to project total water demand, and also the respective shares of the different categories of demand (basic demand, intermediate demand and additional uses). These projections are performed under different combined scenarios of population, GDP and water costs.

Feasibility and potential effects of the proposed Amargosa Creek Recharge Project, Palmdale, California

USGS Publications Warehouse

Christensen, Allen H.; Siade, Adam J.; Martin, Peter; Langenheim, V.E.; Catchings, Rufus D.; Burgess, Matthew K.

2015-09-17

The hydraulic conductivities of faults were estimated on the basis of water-level data and an estimate of natural recharge along Amargosa Creek. With assumed horizontal hydraulic conductivities of 10 and 100 feet per day in the upper 150 feet, the simulated maximum artificial recharge rates to the regional flow system at the ACRP were 3,400 and 9,400 acre-feet per year, respectively. These maximum recharge rates were limited primarily by the horizontal hydraulic conductivity in the upper 150 feet and by the liquefaction constraint. Future monitoring of water-level and soil-water content changes during the proposed project would allow improved estimation of aquifer hydraulic properties, the effect of the faults on groundwater movement, and the overall recharge capacity of the ACRP.

Level 1 Water-Quality Inventory of Baseline Levels of Pesticides in Urban Creeks - Golden Gate National Recreation Area and the Presidio of San Francisco, California

USGS Publications Warehouse

Hladik, Michelle; Orlando, James L.

2008-01-01

To characterize baseline water-quality levels of pesticides in Golden Gate National Recreation Area and the Presidio of San Francisco, the U.S. Geological Survey collected and analyzed surface-water and bed-sediment samples at 10 creeks during February, April, and July 2006. Pesticide data were obtained using previously developed methods. Samples from sites in the Presidio were analyzed only for pyrethroid insecticides, whereas the remaining samples were analyzed for pyrethroids and additional current and historical-use pesticides. Pesticide concentrations were low in both the water (below 30 ng/L) and sediment (below 3 ng/g). The pyrethroid bifenthrin was detected in water samples from two sites at concentrations below 2 ng/L. Other compounds detected in water included the herbicides dacthal (DCPA) and prometryn, the insecticide fipronil, the insecticide degradates p,p'-DDE and fipronil sulfone, and the fungicides cyproconazole, myclobutanil and tetraconazole. The only pesticides detected in the sediment samples were p,p'-DDT and its degradates (p,p'-DDD and p,p'-DDE). Pesticide information from the samples collected can provide a reference point for future sampling and can help National Park Service managers assess the water quality of the urban creeks.

Future Climate Impacts on Crop Water Demand and Groundwater Longevity in Agricultural Regions

NASA Astrophysics Data System (ADS)

Russo, T. A.; Sahoo, S.; Elliott, J. W.; Foster, I.

2016-12-01

Improving groundwater management practices under future drought conditions in agricultural regions requires three steps: 1) estimating the impacts of climate and drought on crop water demand, 2) projecting groundwater availability given climate and demand forcing, and 3) using this information to develop climate-smart policy and water use practices. We present an innovative combination of models to address the first two steps, and inform the third. Crop water demand was simulated using biophysical crop models forced by multiple climate models and climate scenarios, with one case simulating climate adaptation (e.g. modify planting or harvest time) and another without adaptation. These scenarios were intended to represent a range of drought projections and farm management responses. Nexty, we used projected climate conditions and simulated water demand across the United States as inputs to a novel machine learning-based groundwater model. The model was applied to major agricultural regions relying on the High Plains and Mississippi Alluvial aquifer systems in the US. The groundwater model integrates input data preprocessed using single spectrum analysis, mutual information, and a genetic algorithm, with an artificial neural network model. Model calibration and test results indicate low errors over the 33 year model run, and strong correlations to groundwater levels in hundreds of wells across each aquifer. Model results include a range of projected groundwater level changes from the present to 2050, and in some regions, identification and timeframe of aquifer depletion. These results quantify aquifer longevity under climate and crop scenarios, and provide decision makers with the data needed to compare scenarios of crop water demand, crop yield, and groundwater response, as they aim to balance water sustainability with food security.

Predicting future US water yield and ecosystem productivity by linking an ecohydrological model to WRF dynamically downscaled climate projections

NASA Astrophysics Data System (ADS)

Sun, S.; Sun, G.; Cohen, E.; McNulty, S. G.; Caldwell, P.; Duan, K.; Zhang, Y.

2015-12-01

Quantifying the potential impacts of climate change on water yield and ecosystem productivity (i.e., carbon balances) is essential to developing sound watershed restoration plans, and climate change adaptation and mitigation strategies. This study links an ecohydrological model (Water Supply and Stress Index, WaSSI) with WRF (Weather Research and Forecasting Model) dynamically downscaled climate projections of the HadCM3 model under the IPCC SRES A2 emission scenario. We evaluated the future (2031-2060) changes in evapotranspiration (ET), water yield (Q) and gross primary productivity (GPP) from the baseline period of 1979-2007 across the 82 773 watersheds (12 digit Hydrologic Unit Code level) in the conterminous US (CONUS), and evaluated the future annual and monthly changes of hydrology and ecosystem productivity for the 18 Water Resource Regions (WRRs) or 2-digit HUCs. Across the CONUS, the future multi-year means show increases in annual precipitation (P) of 45 mm yr-1 (6 %), 1.8 °C increase in temperature (T), 37 mm yr-1 (7 %) increase in ET, 9 mm yr-1 (3 %) increase in Q, and 106 g C m-2 yr-1 (9 %) increase in GPP. Response to climate change was highly variable across the 82, 773 watersheds, but in general, the majority would see consistent increases in all variables evaluated. Over half of the 82 773 watersheds, mostly found in the northeast and the southern part of the southwest would have an increase in annual Q (>100 mm yr-1 or 20 %). This study provides an integrated method and example for comprehensive assessment of the potential impacts of climate change on watershed water balances and ecosystem productivity at high spatial and temporal resolutions. Results will be useful for policy-makers and land managers in formulating appropriate watershed-specific strategies for sustaining water and carbon sources in the face of climate change.

Assessment of climate change impact on water diversion strategies of Melamchi Water Supply Project in Nepal

NASA Astrophysics Data System (ADS)

Shrestha, Sangam; Shrestha, Manish; Babel, Mukand S.

2017-04-01

This paper analyzes the climate change impact on water diversion plan of Melamchi Water Supply Project (MWSP) in Nepal. The MWSP is an interbasin water transfer project aimed at diverting water from the Melamchi River of the Indrawati River basin to Kathmandu Valley for drinking water purpose. Future temperature and precipitation of the basin were predicted using the outputs of two regional climate models (RCMs) and two general circulation models (GCMs) under two representative concentration pathway (RCP) scenarios which were then used as inputs to Soil and Water Assessment Tool (SWAT) to predict the water availability and evaluate the water diversion strategies in the future. The average temperature of the basin is projected to increase by 2.35 to 4.25 °C under RCP 4.5 and RCP 8.5, respectively, by 2085s. The average precipitation in the basin is projected to increase by 6-18 % in the future. The annual water availability is projected to increase in the future; however, the variability is observed in monthly water availability in the basin. The water supply and demand scenarios of Kathmandu Valley was also examined by considering the population increase, unaccounted for water and water diversion from MWSP in the future. It is observed that even with the additional supply of water from MWSP and reduction of unaccounted for water, the Kathmandu Valley will be still under water scarcity in the future. The findings of this study can be helpful to formulate water supply and demand management strategies in Kathmandu Valley in the context of climate change in the future.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koo, Ja-Kong; Do, Nam-Young

The K site near Seoul began landfilling in 1992. The landfilled wastes include municipal solid waste (66.4%), construction residues (20.4%), water and wastewater sludges (trace levels), and hazardous waste (trace levels). The water content of the municipal solid waste is very high (47.3%); as a result, the leachate level (average E.L.) of the landfill, the design value of which is 7.0 m, was measured at 10.3 m in January 1995 and is increasing. The increase of leachate level in the landfill site causes a problem with slope stability. The leachate level at each disposal stage divided by the intermediate covermore » layer was calculated with the HELP (Hydrologic Evaluation of Landfill Performance) model and calibrated with the data measured from February 1993 to June 1995. Also, the hydraulic conductivities of the waste layer and the intermediate cover layer in each stage were calibrated continuously with HELP model analysis. To verify these results, the total water balance in the landfill site was calculated using the infiltration rate calculated from HELP modeling. The leachate level was E.L. 10.0 m, which was close to the measured leachate level. To estimate the change of the leachate level in the future, the total water balances with different leachate discharge rates of 3,000, 3,500, and 5,000 m{sup 3}/day were analyzed. When the leachate discharge rate was 5,000 ton/day and the initial water content was decreased below 25%, the average leachate level was 10.8 m. This result satisfies the safety factor requirements (=1.3) for landfill slope stability. 4 refs., 8 figs., 1 tab.« less

Intermittent surface water connectivity: Fill and spill vs. fill and merge dynamics

USGS Publications Warehouse

Leibowitz, Scott G.; Mushet, David M.; Newton, Wesley E.

2016-01-01

Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining differences in response was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes.

Opinion of residents from the Gold Coast, Queensland, on community water fluoridation.

PubMed

Kroon, Jeroen; Reid, Kate Emily; Cutting, Jenna Renae; Lalloo, Ratilal; Chiu, Kandy Chien

2014-02-01

To investigate opinions and concerns of Gold Coast residents regarding fluoridation of community water supplies. Anonymous data were collected in four major shopping centers from approximately 500 Gold Coast residents. Eighty-one percent of participants were aware of the addition of fluoride to the water supply. More than half obtained information on water fluoridation through the print and electronic media. Sixty percent of respondents supported water fluoridation. The majority preferred the public and/or health professionals to have made the decision on water fluoridation rather than the government. The percentage of residents supporting water fluoridation was lower than that found in other Queensland, Australian, and worldwide surveys. In this study, only age and the highest level of education attained were factors significantly related to levels of support for water fluoridation. The Queensland Government's decision to implement water fluoridation without a referendum caused disquiet amongst some Gold Coast residents. Future public health initiatives therefore may be assisted by more consultation with, and involvement from, health professionals in the relevant fields. Public health campaigns may benefit more from interaction with the community in order to address their specific concerns. © 2012 Wiley Publishing Asia Pty Ltd.

Declining Groundwater Levels in North India: Understanding Sources of Irrigation Inefficiency

NASA Astrophysics Data System (ADS)

O'Keeffe, J.; Buytaert, W.; Mijic, A.; Brozovic, N.

2014-12-01

Over the last half century, the green revolution has transformed India from a famine-prone, drought-susceptible country, into the world's third largest grain producer and one of the most intensely irrigated regions on the planet. This is in no small part due to the country's vast water resources along with an increase in tubewells and more advanced abstraction methods. While agricultural intensification has had undeniable benefits, it has, and continues to have a significant impact on water resources. Unless solutions which take into consideration the ever evolving socio-economic, hydrological and climatic conditions are found, India's agricultural future looks bleak.This research examines the irrigation behaviour of farmers, using data collected during field work in the State of Uttar Pradesh within the Ganges Basin of North India. Significant differences in farmer behaviour and irrigation practices are highlighted, not only between State districts but between individual farmers. This includes the volume of irrigation water applied and the price paid, as well as differences in the yields of crops produced. Analyses of results suggest that this is due to a number of factors, particularly the source of irrigation water. Study areas which had access to cheaper, but crucially less reliable, canal water were found to invest in more efficient water saving technologies in order to reduce the overall cost of irrigation during periods where less expensive canal water is not available. As a result, overall water use and irrigation cost is lower and yields are higher despite very similar climatic conditions. While cheap canal water is not an option for all farmers, the results show that the introduction of more efficient water saving technologies, despite the significant capital expenditure is a viable option for many farmers and costs can be recovered in a relatively short space of time. In addition, the reduction of declining water levels mean that water is abstracted from a shallower depths, resulting in an extra cost saving. The impacts and practicalities of introducing more water efficient technologies are discussed and their potential impact on water resources and farmer livelihoods, pointing the way to a realistic and more sustainable balance between agriculture and sustainable water resources in the future.

Conceptual model of water resources in the Kabul Basin, Afghanistan

USGS Publications Warehouse

Mack, Thomas J.; Akbari, M. Amin; Ashoor, M. Hanif; Chornack, Michael P.; Coplen, Tyler B.; Emerson, Douglas G.; Hubbard, Bernard E.; Litke, David W.; Michel, Robert L.; Plummer, Niel; Rezai, M. Taher; Senay, Gabriel B.; Verdin, James P.; Verstraeten, Ingrid M.

2010-01-01

The United States (U.S.) Geological Survey has been working with the Afghanistan Geological Survey and the Afghanistan Ministry of Energy and Water on water-resources investigations in the Kabul Basin under an agreement supported by the United States Agency for International Development. This collaborative investigation compiled, to the extent possible in a war-stricken country, a varied hydrogeologic data set and developed limited data-collection networks to assist with the management of water resources in the Kabul Basin. This report presents the results of a multidisciplinary water-resources assessment conducted between 2005 and 2007 to address questions of future water availability for a growing population and of the potential effects of climate change. Most hydrologic and climatic data-collection activities in Afghanistan were interrupted in the early 1980s as a consequence of war and civil strife and did not resume until 2003 or later. Because of the gap of more than 20 years in the record of hydrologic and climatic observations, this investigation has made considerable use of remotely sensed data and, where available, historical records to investigate the water resources of the Kabul Basin. Specifically, this investigation integrated recently acquired remotely sensed data and satellite imagery, including glacier and climatic data; recent climate-change analyses; recent geologic investigations; analysis of streamflow data; groundwater-level analysis; surface-water- and groundwater-quality data, including data on chemical and isotopic environmental tracers; and estimates of public-supply and agricultural water uses. The data and analyses were integrated by using a simplified groundwater-flow model to test the conceptual model of the hydrologic system and to assess current (2007) and future (2057) water availability. Recharge in the basin is spatially and temporally variable and generally occurs near streams and irrigated areas in the late winter and early spring. In irrigated areas near uplands or major rivers, the annual recharge rate may be about 1.2 ? 10-3 meters per year; however, in areas at lower altitude with little irrigation, the recharge rate may average about 0.7 ? 10-3 meters per year. With increasing population, the water needs of the Kabul Basin are estimated to increase from 112,000 cubic meters per day to about 725,000 cubic meters per day by the year 2057. In some areas of the basin, particularly in the north along the western mountain front and near major rivers, water resources are generally adequate for current needs. In other areas of the basin, such as in the east and away from major rivers, the available water resources may not meet future needs. On the basis of the model simulations, increasing withdrawals are likely to result in declining water levels that may cause more than 50 percent of shallow (typically less than 50 meters deep) supply wells to become dry or inoperative. The water quality in the shallow (less than 100 meters thick), unconsolidated primary aquifer has deteriorated in urban areas because of poor sanitation. Concerns about water availability may be compounded by poor well-construction practices and lack of planning. Future water resources of the Kabul Basin will likely be reduced as a result of increasing air temperatures associated with global climate change. It is estimated that at least 60 percent of shallow groundwater-supply wells would be affected and may become dry or inoperative as a result of climate change. These effects of climate change would likely be greatest in the agricultural areas adjacent to the Paghman Mountains where a majority of springs, karezes, and wells would be affected. The water available in the shallow primary aquifer of the basin may meet future water needs in the northern areas of the Kabul Basin near the Panjsher River. Conceptual groundwater-flow simulations indicate that the basin likely has groundwater reserves in unused unconsolidate

Relative sea-level rise as indicated by gage data along the Mississippi and Alabama Gulf Coasts

USGS Publications Warehouse

Van Wilson, K.

2004-01-01

Global warming, or the increasing of earth's temperatures, leads to rising sea level as polar ice caps and mountain glaciers melt and ocean water undergoes thermal expansion. Tidal records collected by the U.S. Army Corps of Engineers (COE), Mobile District, at Gulfport, Biloxi, and Pascagoula, Mississippi, and at Mobile, Alabama, indicate trends of water-surface elevations increasing with time (relative sea-level rise). The trends indicated by the COE data were compared to relative sea-level trends indicated by the National Ocean Survey gages in the Gulf of Mexico. The average global rate of sea level rise has been suggested to approach about 2 mm/yr (0.007 ft/yr). Some leading scientists have suggested rates of sea level rise that are greater than 2 mm/yr, when accounting for effects of greenhouse gas emissions. As the sea level rises and inundates the coastal plain, structures along the existing coast and structures located in the back bays of estuaries will be even more adversely affected by future flooding. Also, if the land surface adjacent to the water also sinks due to soil compaction and other geologic processes (collectively call subsidence), additional land will be inundated. Copyright ASCE 2004.

Climate and water resource change impacts and adaptation potential for US power supply

DOE PAGES

Miara, Ariel; Macknick, Jordan E.; Vorosmarty, Charles J.; ...

2017-10-30

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptationmore » strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. As a result, climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.« less

Climate and water resource change impacts and adaptation potential for US power supply

NASA Astrophysics Data System (ADS)

Miara, Ariel; Macknick, Jordan E.; Vörösmarty, Charles J.; Tidwell, Vincent C.; Newmark, Robin; Fekete, Balazs

2017-11-01

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptation strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. Climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.

Changes in Central Asia’s Water Tower: Past, Present and Future

PubMed Central

Chen, Yaning; Li, Weihong; Deng, Haijun; Fang, Gonghuan; Li, Zhi

2016-01-01

The Tienshan Mountains, with its status as “water tower”, is the main water source and ecological barrier in Central Asia. The rapid warming affected precipitation amounts and fraction as well as the original glacier/snowmelt water processes, thereby affecting the runoff and water storage. The ratio of snowfall to precipitation (S/P) experienced a downward trend, along with a shift from snow to rain. Spatially, the snow cover area in Middle Tienshan Mountains decreased significantly, while that in West Tienshan Mountains increased slightly. Approximately 97.52% of glaciers in the Tienshan Mountains showed a retreating trend, which was especially obvious in the North and East Tienshan Mountains. River runoff responds in a complex way to changes in climate and cryosphere. It appears that catchments with a higher fraction of glacierized area showed mainly increasing runoff trends, while river basins with less or no glacierization exhibited large variations in the observed runoff changes. The total water storage in the Tienshan Mountains also experienced a significant decreasing trend in Middle and East Tienshan Mountains, but a slight decreasing trend in West Tienshan Mountains, totally at an average rate of −3.72 mm/a. In future, water storage levels are expected to show deficits for the next half-century. PMID:27762285

Climate and water resource change impacts and adaptation potential for US power supply

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miara, Ariel; Macknick, Jordan E.; Vorosmarty, Charles J.

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptationmore » strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. As a result, climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.« less

Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Susko, Michele L.; Bloom, Michael S., E-mail: mbloom@albany.edu; Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York

High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnairemore » and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did not affect time to pregnancy among women conceiving quickly. • Arsenic increased time to pregnancy among women taking longer to conceive. • Low level drinking water arsenic may adversely impact women with lower fecundity.« less

Strengthening Sustainability and Resiliency of a Future Force, Phase 1. FY2010-2011 Summer Study

DTIC Science & Technology

2011-03-01

Resiliency of a Future Force: Phase I Interim Report - 48 Please Enter Custom Water factor adjustments below: m Unit Level* (Gat/Ptisan/ Dti ...cost of mov- ing the consumables in terms of the assets required to move the commodity and the security Intra Theater Resupply: 4 Legs Army...Expeditionary Force-Logistics ResupplyDetails Legl Leg 2 Leg 3 Leg 4 Resupply Trip Legs Super FOB (Div)to Base Camp (bde) Base Camp (Bde) to FOB (Bn

Water Resources Study for Metropolitan Chester Creek Basin, Pennsylvania.

DTIC Science & Technology

1978-09-01

premium is the second most effective method of calling attention to the flood risk . The first is a flood itself. Presumably the cost will encourage the...communities in the Basin. Due to the high risks in- volved people should strive to keep the coverage current and at the maximim level allowed. Permanent Flood...result of future development of upstream areas, and the eight lives lost in the flood of record and future risk of the loss of lives. I have determined

Extravehicular activities limitations study. Volume 1: Physiological limitations to extravehicular activity in space

NASA Technical Reports Server (NTRS)

Furr, Paul A.; Monson, Conrad B.; Santoro, Robert L.; Sears, William J.; Peterson, Donald H.; Smith, Malcolm

1988-01-01

This report contains the results of a comprehensive literature search on physiological aspects of EVA. Specifically, the topics covered are: (1) Oxygen levels; (2) Optimum EVA work; (3) Food and Water; (4) Carbon dioxide levels; (5) Repetitive decompressions; (6) Thermal, and (7) Urine collection. The literature was assessed on each of these topics, followed by statements on conclusions and recommended future research needs.

Index-based framework for assessing climate change impact on wetlands in Poland

NASA Astrophysics Data System (ADS)

O'Keeffe, Joanna; Marcinkowski, Paweł; Utratna, Marta; Szcześniak, Mateusz; Piniewski, Mikołaj; Okruszko, Tomasz

2017-04-01

Climate change is expected to impact the water cycle through changing the precipitation levels, river streamflows, soil moisture dynamics and therefore pose a threat to groundwater and surface-water fed wetlands and their biodiversity. We examined the past trends and future impacts of climate change on streamflow and soil water content. Simulation results from 1971 to 2000 (historical period) and from 2021 to 2100 (future period) were obtained with the use of the Soil and Water Assessment Tool (SWAT). Hydrological modelling was driven by a set of nine EUROCORDEX Regional Climate Models under two Representative Concentration Pathways (RCP's) of greenhouse gas concentration trajectories: 4.5 and 8.5. A special focus was made on water dependent habitats within the Special Areas of Conservation (SAC's) of the Natura 2000 network located within Odra and Vistula River basins in Poland. A habitat assessment was carried out to distinguish groundwater and surface water fed wetlands. By establishing threshold values of streamflow at bankfull flow we were able to identify flood events. Changes in frequency of the floods informed about the alteration to the water supply for wetlands reliant on inundation. The groundwater-fed wetlands were assessed on the basis of the soil water content. The model outputs were used to develop indices which were calculated for the climate change scenarios. Comparisons of simulated trends in soil water content and streamflow dynamics with average annual precipitation showed largely consistent patterns. The developed indicators are sensitive to projected changes in hydrologic regime in the conditions of changing climate. The results show influence of climate change on floodplain and groundwater-fed wetlands and show the number and kind of wetlands threatened in different regions of Poland. SAC's will play an important role of buffers and water regulators as soil water content in SAC's is projected to be higher than average for the future scenarios.

A NOAA/NOS Sea Level Advisory

NASA Astrophysics Data System (ADS)

Sweet, W.

2011-12-01

In order for coastal communities to realize current impacts and become resilient to future changes, sea level advisories/bulletins are necessary that systematically monitor and document non-tidal anomalies (residuals) and flood-watch (elevation) conditions. The need became apparent after an exceptional sea level anomaly along the U.S. East Coast in June - July of 2009 when higher than normal sea levels coincided with a perigean-spring tide and flooded many coastal regions. The event spurred numerous public inquiries to the National Oceanic and Atmospheric Administration's (NOAA) Center for Operational Oceanographic Products and Services (CO-OPS) from coastal communities concerned because of the lack of any coastal storm signatures normally associated with such an anomaly. A subsequent NOAA report provided insight into some of the mechanisms involved in the event and methods for tracking their reoccurrences. NOAA/CO-OPS is the U.S. authority responsible for defining sea level datums and tracking their relative changes in support of marine navigation and national and state land-use boundaries. These efforts are supported by the National Water Level Observation Network (NWLON), whose long-term and widespread observations largely define a total water level measurement impacting a coastal community. NWLON time series provide estimates of local relative sea level trends, a product increasingly utilized by various stakeholders planning for the future. NWLON data also capture significant short-term changes and conveyance of high-water variations (from surge to seasonal scale) provides invaluable insight into inundation patterns ultimately needed for a more comprehensive planning guide. A NOAA/CO-OPS Sea Level Advisory Project will enhance high-water monitoring capabilities by: - Automatically detecting sea level anomalies and flood-watch occurrences - Seasonally calibrating the anomaly thresholds to a locality in terms of flood potential - Alerting for near-term superposition of non-tidal residuals and large tide-range changes (i.e., spring tides). - Identifying important regional physical forcing mechanisms (both meteorological and oceanographic) to help explain the conditions - Displaying near-real time and archived information to establish a clear and direct communication with a community in regards to its past, present and future flood patterns. An example is presented for Charleston, SC, an area with little remaining free board in terms of its downtown infrastructure. The National Weather Service (NWS) issues multiple flood watches for Charleston every year that largely result from astronomical (earth-sun-moon system) tide forcing alone and NOAA's Coastal Services Center (CSC) often receives inquiries regarding downtown flooding during sunny, nondescript days. This project will allow for a deeper appreciation of surge-to-seasonal patterns of variability and compliment a community's living memory of sea level elevations/impacts needed to motivate societal adaptation as sea levels rise. Coordination with NWS's local Weather Forecasting Offices (WFO) is planned and the project will expand to other incident-prone regions once demonstration is accepted.

Ground-water levels in intermontane basins of the northern Rocky Mountains, Montana and Idaho

USGS Publications Warehouse

Briar, David W.; Lawlor, S.M.; Stone, M.A.; Parliman, D.J.; Schaefer, J.L.; Kendy, Eloise

1996-01-01

The Regional Aquifer-System Analysis (RASA) program is a series of studies by the U.S. Geological Survey (USGS) to analyze regional ground-water systems that compose a major portion of the Nation's water supply (Sun, 1986). The Northern Rocky Mountains Intermontane Basins is one of the study regions in this national program. The main objectives of the RASA studies are to (1) describe the groundwater systems as they exist today, (2) analyze the known changes that have led to the systems present condition, (3) combine results of previous studies in a regional analysis, where possible, and (4) provide means by which effects of future ground-water development can be estimated.The purpose of this study, which began in 1990, was to increase understanding of the hydrogeology of the intermontane basins of the Northern Rocky Mountains area. This report is Chapter B of a three-part series and shows the general distribution of ground-water levels in basin-fill deposits in the study area. Chapter A (Tuck and others, 1996) describes the geologic history and generalized hydrogeologic units. Chapter C (Clark and Dutton, 1996) describes the quality of ground and surface waters in the study area.Ground-water levels shown in this report were measured primarily during summer 1991 and summer 1992; however, historical water levels were used for areas where more recent data could not be obtained. The information provided allows for the evaluation of general directions of ground-water flow, identification of recharge and discharge areas, and determination of hydraulic gradients within basin-fill deposits.

Chlorine dioxide water disinfection: a prospective epidemiology study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael, G.E.; Miday, R.K.; Bercz, J.P.

An epidemiologic study of 198 persons exposed for 3 months to drinking water disinfected with chlorine dioxide was conducted in a rural village. A control population of 118 nonexposed persons was also studied. Pre-exposure hematologic and serum chemical parameters were compared with test results after 115 days of exposure. Chlorite ion levels in the water averaged approximately 5 ppM during the study period. Statistical analysis (ANOVA) of the data failed to identify any significant exposure-related effects. This study suggests that future evaluations of chlorine dioxide disinfection should be directed toward populations with potentially increased sensitivity to hemolytic agents.

Potential and limitations of satellite laser altimetry for monitoring water surface dynamics: ICESat for US lakes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shu, Liu; Qigang, Jiang; Zhang, Xuesong

Elevation measurements from the Ice, Cloud and Land Elevation Satellite (ICESat) have been applied to monitor dynamics of lakes and other surface water bodies. Despite such potential, the true utility of ICESat--more generally, satellite laser altimetry--for tracking surface water dynamics over time has not been adequately assessed, especially in the continental or global contexts. Here, we analyzed ICESat elevation data for the conterminous United States and examined the potential and limitations of satellite laser altimetry in measuring water-level dynamics. Owing to a lack of spatially-explicit ground-based water-level data, we first resorted to high-fidelity land elevation data acquired by airborne lidarmore » to quantify ICESat’s ranging accuracy. We then performed trend and frequency analyses to evaluate how reliably ICESat could capture water-level dynamics over a range of temporal scales, as compared to in-situ gauge measurements. Our analyses showed that ICESat had a vertical ranging error of 0.16 m at the footprint level—a limit on the detectable range of water-level dynamics. The sparsity of data over time was identified as a major factor limiting the use of ICESat for water dynamics studies. Of all the US lakes, only 361 had quality ICESat measurements for more than two flight passes. Even for those lakes with sufficient temporal coverage, ICESat failed to capture the true interannual water-level dynamics in 68% of the cases. Our frequency analysis suggested that even with a repeat cycle of two months, ICESat could capture only 60% of the variations in water-level dynamics for at most 34 % of the US lakes. To capture 60% of the water-level variation for most of the US lakes, a weekly repeat cycle (e.g., less than 5 days) is needed – a requirement difficult to meet in current designs of spaceborne laser altimetry. Overall, our results highlight that current or near-future satellite laser missions, though with high ranging accuracies, are unlikely to fulfill the general needs in remotely monitoring water surface dynamics for lakes or reservoirs.« less

Climate change and prairie pothole wetlands: mitigating water-level and hydroperiod effects through upland management

USGS Publications Warehouse

Renton, David A.; Mushet, David M.; DeKeyser, Edward S.

2015-01-01

Prairie pothole wetlands offer crucial habitat for North America’s waterfowl populations. The wetlands also support an abundance of other species and provide ecological services valued by society. The hydrology of prairie pothole wetlands is dependent on atmospheric interactions. Therefore, changes to the region’s climate can have profound effects on wetland hydrology. The relevant literature related to climate change and upland management effects on prairie pothole wetland water levels and hydroperiods was reviewed. Climate change is widely expected to affect water levels and hydroperiods of prairie pothole wetlands, as well as the biota and ecological services that the wetlands support. In general, hydrologic model projections that incorporate future climate change scenarios forecast lower water levels in prairie pothole wetlands and longer periods spent in a dry condition, despite potential increases in precipitation. However, the extreme natural variability in climate and hydrology of prairie pothole wetlands necessitates caution when interpreting model results. Recent changes in weather patterns throughout much of the Prairie Pothole Region have been in increased precipitation that results in increased water inputs to wetlands above losses associated with warmer temperatures. However, observed precipitation increases are within the range of natural climate variability and therefore, may not persist. Identifying management techniques with the potential to affect water inputs to prairie pothole wetlands would provide increased options for managers when dealing with the uncertainties associated with a changing climate. Several grassland management techniques (for example, grazing and burning) have the potential to affect water levels and hydroperiods of prairie pothole by affecting infiltration, evapotranspiration, and snow deposition.

Analysis of projected water availability with current basin management plan, Pajaro Valley, California

NASA Astrophysics Data System (ADS)

Hanson, R. T.; Lockwood, B.; Schmid, Wolfgang

2014-11-01

The projection and analysis of the Pajaro Valley Hydrologic Model (PVHM) 34 years into the future using MODFLOW with the Farm Process (MF-FMP) facilitates assessment of potential future water availability. The projection is facilitated by the integrated hydrologic model, MF-FMP that fully couples the simulation of the use and movement of water from precipitation, streamflow, runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. MF-FMP allows for more complete analysis of conjunctive-use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface-water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within ;water-balance subregions; (WBS) comprised of one or more model cells that can represent a single farm, a group of farms, watersheds, or other hydrologic or geopolitical entities. Analysis of conjunctive use would be difficult without embedding the fully coupled supply-and-demand into a fully coupled simulation, and are difficult to estimate a priori. The analysis of projected supply and demand for the Pajaro Valley indicate that the current water supply facilities constructed to provide alternative local sources of supplemental water to replace coastal groundwater pumpage, but may not completely eliminate additional overdraft. The simulation of the coastal distribution system (CDS) replicates: 20 miles of conveyance pipeline, managed aquifer recharge and recovery (MARR) system that captures local runoff, and recycled-water treatment facility (RWF) from urban wastewater, along with the use of other blend water supplies, provide partial relief and substitution for coastal pumpage (aka in-lieu recharge). The effects of these Basin Management Plan (BMP) projects were analyzed subject to historical climate variations and assumptions of 2009 urban water demand and land use. Water supplied directly from precipitation, and indirectly from reuse, captured local runoff, and groundwater is necessary but inadequate to satisfy agricultural demand without coastal and regional storage depletion that facilitates seawater intrusion. These facilities reduce potential seawater intrusion by about 45% with groundwater levels in the four regions served by the CDS projected to recover to levels a few feet above sea level. The projected recoveries are not high enough to prevent additional seawater intrusion during dry-year periods or in the deeper aquifers where pumpage is greater. While these facilities could reduce coastal pumpage by about 55% of the historical 2000-2009 pumpage for these regions, and some of the water is delivered in excess of demand, other coastal regions continue to create demands on coastal pumpage that will need to be replaced to reduce seawater intrusion. In addition, inland urban and agricultural demands continue to sustain water levels below sea level causing regional landward gradients that also drive seawater intrusion. Seawater intrusion is reduced by about 45% but it supplies about 55% of the recovery of groundwater levels in the coastal regions served by the CDS. If economically feasible, water from summer agricultural runoff and tile-drain returnflows could be another potential local source of water that, if captured and reused, could offset the imbalance between supply and demand as well as reducing discharge of agricultural runoff into the National Marine Sanctuary of Monterey Bay. A BMP update (2012) identifies projects and programs that will fund a conservation program and will provide additional, alternative water sources to reduce or replace coastal and inland pumpage, and to replenish the aquifers with managed aquifer recharge in an inland portion of the Pajaro Valley.

Status of Ground-Water Levels and Storage Volume in the Equus Beds Aquifer Near Wichita, Kansas, January 2003-January 2006

USGS Publications Warehouse

Hansen, Cristi V.

2007-01-01

The Equus Beds aquifer northwest of Wichita, Kansas, was developed to supply water to Wichita residents and for irrigation in south-central Kansas. Ground-water pumping for city and agricultural use from the aquifer caused water levels to decline in a large part of the aquifer northwest of Wichita. Irrigation pumpage in the area increased substantially during the 1970s and 1980s and accelerated water-level declines. A period of water-level rises associated with greater-than-average precipitation and decreased city pumpage from the area began in 1993. An important factor in the decreased city pumpage was increased use of Cheney Reservoir as a water-supply source by the city of Wichita; as a result, city pumpage from the Equus Beds aquifer during 1993-2005 decreased to quantities similar to those pumped in the 1940s and went from being about 60 percent to about 40 percent of Wichita's water usage. Since 1995, the city also has been investigating the use of artificial recharge in the study area to meet future water-supply needs and to protect the aquifer from the intrusion of saltwater from sources to the west. During January 2006, the direction of ground-water flow in the Equus Beds aquifer in the area was generally from west to east, similar to the direction prior to development of the aquifer. Water-level changes since 1940 for the period January 2003-January 2006 ranged from a decline of more than 36 feet to a rise of more than 2 feet. Almost all wells in the area had small cumulative water-level rises from January 2003 to January 2006 and larger rises from October 1992 (period of maximum storage loss) to January 2006. The water-level rises from October 1992 to January 2006 probably are due principally to decreases in city pumpage, with increases in recharge due to increased precipitation during the period also a contributing factor. Irrigation pumpage increased during the period, so irrigation did not contribute to the rises in water levels between the beginning and end of the period. The storage volume change from October 1992 to January 2006 represents a recovery of about 55 percent of the storage volume previously lost between August 1940 and October 1992.

A System Dynamics Modeling of Water Supply and Demand in Las Vegas Valley

NASA Astrophysics Data System (ADS)

Parajuli, R.; Kalra, A.; Mastino, L.; Velotta, M.; Ahmad, S.

2017-12-01

The rise in population and change in climate have posed the uncertainties in the balance between supply and demand of water. The current study deals with the water management issues in Las Vegas Valley (LVV) using Stella, a system dynamics modeling software, to model the feedback based relationship between supply and demand parameters. Population parameters were obtained from Center for Business and Economic Research while historical water demand and conservation practices were modeled as per the information provided by local authorities. The water surface elevation of Lake Mead, which is the prime source of water supply to the region, was modeled as the supply side whereas the water demand in LVV was modeled as the demand side. The study was done from the period of 1989 to 2049 with 1989 to 2012 as the historical one and the period from 2013 to 2049 as the future period. This study utilizes Coupled Model Intercomparison Project data sets (2013-2049) (CMIP3&5) to model different future climatic scenarios. The model simulates the past dynamics of supply and demand, and then forecasts the future water budget for the forecasted future population and future climatic conditions. The results can be utilized by the water authorities in understanding the future water status and hence plan suitable conservation policies to allocate future water budget and achieve sustainable water management.

Biochar: What is the future for industrial production and world usage?

USDA-ARS?s Scientific Manuscript database

Biochar has gained world attention as a soil amendment to increase carbon sequestration, improve fertility levels and bolster soil water retention. Unfortunately, the amount of biochar needed for field application rates to achieve these results can be in the tons per hectare range. There is concer...

Scenario analysis for sustainable development of Chongming Island: water resources sustainability.

PubMed

Ni, Xiong; Wu, Yanqing; Wu, Jun; Lu, Jian; Wilson, P Chris

2012-11-15

With the socioeconomic and urban development of Chongming Island (the largest alluvial island in the world), water demand is rapidly growing. To make adjustments to the water utilization structure of each industry, allocate limited water resources, and increase local water use efficiency, this study performed a scenario analysis for the water sustainability of Chongming Island. Four different scenarios were performed to assess the water resource availability by 2020. The growth rate for water demand will be much higher than that of water supply under a serious situation prediction. The water supply growth volume will be 2.22 × 10(8)m(3) from 2010 to 2020 under Scenario I and Scenario II while the corresponding water demand growth volume will be 2.74 × 10(8)m(3) and 2.64 × 10(8)m(3), respectively. There will be a rapid growth in water use benefit under both high and low development modes. The water use benefit will be about 50 CNY/m(3) under Scenarios I and II in 2020. The production structure will need to be adjusted for sustainable utilization of water resources. Sewage drainage but not the forest and grass coverage rate will be a major obstacle to future development and environmental quality. According to a multi-level fuzzy comprehensive evaluation, Scenario II is finally deemed to be the most desirable plan, suggesting that the policy of rapid socioeconomic development and better environmental protection may achieve the most sustainable development of Chongming Island in the future. Copyright © 2012 Elsevier B.V. All rights reserved.

Implications of changing water cycle for the performance and yield characteristics of the multi-purpose Beas Reservoir in India

NASA Astrophysics Data System (ADS)

Adeloye, A. J.; Ojha, C. S.; Soundharajan, B.; Remesan, R.

2013-12-01

There is considerable change in both the spatial and temporal patterns of monsoon rainfall in India, with implications for water resources availability and security. 'Mitigating the Impacts of Climate Change on India Agriculture' (MICCI) is one of five on-going scientific efforts being sponsored as part of the UK-NERC/India-MOES Changing Water Cycle (South Asia) initiative to further the understanding of the problem and proffer solutions that are robust and effective. This paper focuses on assessing the implications of projected climate change on the yield and performance characteristics of the Pong Reservoir on the Beas River, Himachal Pradesh, India. The Pong serves both hydropower and irrigation needs and is therefore strategic for the socio-economic well-being of the region as well as sustaining the livelihoods of millions of farmers that rely on it for irrigation. Simulated baseline and climate-change perturbed hydro-climate scenarios developed as part of a companion Work Package of MICCI formed the basis of the analysis. For both of these scenarios, reservoir analyses were carried out using the Sequent Peak Algorithm (SPA) and Pong's existing level of releases to derive rule curves for the reservoir. These rule curves then formed the basis of further reservoir behaviour simulations in WEAP and the resulting performance of the reservoir was summarised in terms of reliability, resilience, vulnerability and sustainability. The whole exercise was implemented within a Monte Carlo framework for the benefit of characterising the variability in the assessments. The results show that the rule curves developed using future hydro-climate are significantly changed from the baseline in that higher storages will be required to be maintained in the Pong in the future to achieve reliable performance. As far as the overall performance of the reservoir is concerned, future reliability (both time-based and volume-based) is not significantly different from the baseline, provided the future simulations adopt the future rule curves. This is, however, not the case with the resilience, with the future hydro-climate resulting in a less resilient system when compared with the baseline. The resilience is the ability of the system to recover from a hydrological failure; consequently, lower resilience for the future systems is an indication that longer, continuous failure periods are likely with implications for the two purposes of the reservoir. For example, extended periods of water scarcity that may result from a low resilient system will mean that crops are likely to experience longer periods of water stress with implications for crop yields. In such situations, better operational practices that manage the available water through hedging and irrigation water scheduling will be required. Other interventions may include the introduction of water from other sources, e.g. groundwater.

Design of a surface-based factory for the production of life support and technology support products. Phase 2: Integrated water system for a space colony

NASA Technical Reports Server (NTRS)

1989-01-01

Phase 2 of a conceptual design of an integrated water treatment system to support a space colony is presented. This includes a breathable air manufacturing system, a means of drilling for underground water, and storage of water for future use. The system is to supply quality water for biological consumption, farming, residential and industrial use and the water source is assumed to be artesian or subsurface and on Mars. Design criteria and major assumptions are itemized. A general block diagram of the expected treatment system is provided. The design capacity of the system is discussed, including a summary of potential users and the level of treatment required; and, finally, various treatment technologies are described.

USGS ground-water flow model : an essential tool for managing the water supply of the Virginia Coastal Plain

USGS Publications Warehouse

Erwin, Martha L.; McFarland, Randolph E.; Scott, Bruce T.

1999-01-01

Virginia needs a reliable water supply to sustain its growing population and expanding economy. In 1990, the aquifers in the Coastal Plain supplied about 100 million gallons per day (mgd) to the citizens, businesses, and industries of Virginia. It is estimated that by the year 2000, demand will increase by another 10 mgd and likely will continue to increase in future years.Ground water is the only source of usable water in rural areas of the Coastal Plain and increasingly is being used to support a growing urban population. Current withdrawals have led to declining water levels in most Coastal Plain aquifers. Further declines are likely to occur, posing a threat that saltwater will move into parts of these freshwater aquifers.

The Extent to Which Different 100% Clean, Renewable Energy Transition Scenarios can Reduce World Carbon Dioxide Levels to 350-400 ppmv by 2100

NASA Astrophysics Data System (ADS)

Jacobson, M. Z.; Byrne, J. M.

2016-12-01

Future levels of atmospheric carbon dioxide (CO2) depend on CO2's natural and anthropogenic emission rates and its removal rates by primarily water dissolution, photosysnthesis, and weathering. We compare modeled past CO2 from 1750 to 2015 with data then model projected future changes in CO2 under different energy emission scenarios, including two where 100% of the world's all-purpose energy (electricity, transportation, heating/cooling, industry, and agriculture/forestry/fishing) is electrified, and the electricity is powered by wind, water, and sunlight (WWS). The scenarios are derived from country-by-country energy roadmaps found at http://web.stanford.edu/group/efmh/jacobson/Articles/I/WWS-50-USState-plans.html. In one 100% scenario, 80% of the conversion is assumed to occur by 2030 and 100%, by 2050. In the second, 80% is assumed to occur by 2050, and the rest by 2100. We also compare with an unrealistic but best-case 100% conversion scenario starting in 2015 and IPCC scenarios A1B, A2, B1, B2, and A1F1. Results will be shown, and conclusions, drawn about the practicality of reducing CO2 to 350-400 ppmv by 2100. These results have significant impact on current and future energy policy.

Climate-water quality relationships in Texas reservoirs

USGS Publications Warehouse

Gelca, Rodica; Hayhoe, Katharine; Scott-Fleming, Ian; Crow, Caleb; Dawson, D.; Patino, Reynaldo

2015-01-01

Water temperature, dissolved oxygen, and concentrations of salts in surface water bodies can be affected by the natural environment, local human activities such as surface and ground water withdrawals, land use, and energy extraction, and variability and long-term trends in atmospheric conditions including temperature and precipitation. Here, we quantify the relationship between 121 indicators of mean and extreme temperature and precipitation and 24 water quality parameters in 57 Texas reservoirs using observational data records covering the period 1960 to 2010. We find that water temperature, dissolved oxygen, pH, specific conductance, chloride, sulfate, and phosphorus all show consistent correlations with atmospheric predictors, including high and low temperature extremes, dry days, heavy precipitation events, and mean temperature and precipitation over time scales ranging from one week to two years. Based on this analysis and published future projections for this region, we expect climate change to increase water temperatures, decrease dissolved oxygen levels, decrease pH, increase specific conductance, and increase levels of sulfate, chloride in Texas reservoirs. Over decadal time scales, this may affect aquatic ecosystems in the reservoirs, including altering the risk of conditions conducive to algae occurrence, as well as affecting the quality of water available for human consumption and recreation.

Atlantic cod actively avoid CO2 and predator odour, even after long-term CO2 exposure.

PubMed

Jutfelt, Fredrik; Hedgärde, Maria

2013-12-27

The rising atmospheric CO2 level is continuously driving the dissolution of more CO2 into the oceans, and some emission scenarios project that the surface waters may reach 1000 μatm by the end of the century. It is not known if fish can detect moderately elevated CO2 levels, and if they avoid areas with high CO2. If so, avoidance behaviour to water with high CO2 could affect movement patterns and migrations of fish in the future. It is also being increasingly recognized that fish behaviour can be altered by exposure to CO2. Therefore this study investigated how long-term exposure to elevated pCO2 affects predator avoidance and CO2 avoidance in juvenile Atlantic cod (Gadus morhua). The fish were exposed to control water or CO2-enriched water (1000 μatm) for six weeks before being subjected to tests of behaviour. Despite long term exposure to elevated pCO2 the cod still strongly avoided the smell of a predator. These data are surprising because several coral reef fish have demonstrated reversal of olfactory responses after CO2 exposure, turning avoidance of predator cues into preference for predator cues. Fish from both treatment groups also demonstrated strong avoidance of CO2 when presented with the choice of control or CO2-acidified water, indicating that habituation to the CO2 sensory stimuli is negligible. As Atlantic cod maintained normal behavioural responses to olfactory cues, they may be tolerant to CO2-induced behavioural changes. The results also suggest that despite the long-term exposure to CO2-acidified water, the fish still preferred the control water over CO2-acidified water. Therefore, in the future, fish may alter their movements and migrations in search of waters with a lower CO2 content.

Atlantic cod actively avoid CO2 and predator odour, even after long-term CO2 exposure

PubMed Central

2013-01-01

Introduction The rising atmospheric CO2 level is continuously driving the dissolution of more CO2 into the oceans, and some emission scenarios project that the surface waters may reach 1000 μatm by the end of the century. It is not known if fish can detect moderately elevated CO2 levels, and if they avoid areas with high CO2. If so, avoidance behaviour to water with high CO2 could affect movement patterns and migrations of fish in the future. It is also being increasingly recognized that fish behaviour can be altered by exposure to CO2. Therefore this study investigated how long-term exposure to elevated pCO2 affects predator avoidance and CO2 avoidance in juvenile Atlantic cod (Gadus morhua). The fish were exposed to control water or CO2-enriched water (1000 μatm) for six weeks before being subjected to tests of behaviour. Results Despite long term exposure to elevated pCO2 the cod still strongly avoided the smell of a predator. These data are surprising because several coral reef fish have demonstrated reversal of olfactory responses after CO2 exposure, turning avoidance of predator cues into preference for predator cues. Fish from both treatment groups also demonstrated strong avoidance of CO2 when presented with the choice of control or CO2-acidified water, indicating that habituation to the CO2 sensory stimuli is negligible. Conclusions As Atlantic cod maintained normal behavioural responses to olfactory cues, they may be tolerant to CO2-induced behavioural changes. The results also suggest that despite the long-term exposure to CO2-acidified water, the fish still preferred the control water over CO2-acidified water. Therefore, in the future, fish may alter their movements and migrations in search of waters with a lower CO2 content. PMID:24373523

Design, Development, and Testing of a Water Vapor Exchanger for Spacecraft Life Support Systems

NASA Technical Reports Server (NTRS)

Izenson, Michael G.; Micka, Daniel J.; Chepko, Ariane B.; Rule, Kyle C.; Anderson, Molly S.

2016-01-01

Thermal and environmental control systems for future exploration spacecraft must meet challenging requirements for efficient operation and conservation of resources. Maximizing the use of regenerative systems and conserving water are critical considerations. This paper describes the design, development, and testing of an innovative water vapor exchanger (WVX) that can minimize the amount of water absorbed in, and vented from, regenerative CO2 removal systems. Key design requirements for the WVX are high air flow capacity (suitable for a crew of six), very high water recovery, and very low pressure losses. We developed fabrication and assembly methods that enable high-efficiency mass transfer in a uniform and stable array of Nafion tubes. We also developed analysis and design methods to compute mass transfer and pressure losses. We built and tested subscale units sized for flow rates of 2 and 5 cu ft/min (3.4–8.5 cu m/hr). Durability testing demonstrated that a stable core geometry was sustained over many humid/dry cycles. Pressure losses were very low (less than 0.5 in. H2O (125 Pa) total) and met requirements at prototypical flow rates. We measured water recovery efficiency across a range of flow rates and humidity levels that simulate the range of possible cabin conditions. We measured water recovery efficiencies in the range of 80 to 90%, with the best efficiency at lower flow rates and higher cabin humidity levels. We compared performance of the WVX with similar units built using an unstructured Nafion tube bundle. The WVX achieves higher water recovery efficiency with nearly an order of magnitude lower pressure drop than unstructured tube bundles. These results show that the WVX provides uniform flow through flow channels for both the humid and dry streams and can meet requirements for service on future exploration spacecraft. The WVX technology will be best suited for long-duration exploration vehicles that require regenerative CO2 removal systems while needing to conserve water.

Patterns, structures and regulations of domestic water cycle systems in China

NASA Astrophysics Data System (ADS)

Chu, Junying; Wang, Hao; Wang, Jianhua; Qin, Dayong

2010-05-01

Domestic water cycle systems serving as one critical component of artificial water cycle at the catchment's scale, is so closely related to public healthy, human rights and social-economic development, and has gained the highest priority in strategic water resource and municipal infrastructure planning. In this paper, three basic patterns of domestic water cycle systems are identified and analyzed, including rural domestic water system (i.e. primary level), urban domestic water system (i.e. intermediate level) and metropolitan domestic water system (i.e. senior level), with different "abstract-transport-consume-discharge" mechanisms and micro-components of water consumption (such as drinking, cooking, toilet flushing, showering or cleaning). The rural domestic water system is general simple with three basic "abstract-consume-discharge" mechanisms and micro-components of basic water consumption such as drinking, cooking, washing and sanitation. The urban domestic water system has relative complex mechanisms of "abstract-supply-consume-treatment-discharge" and more micro-components of water consumption such as bath, dishwashing or car washing. The metropolitan domestic water system (i.e. senior level) has the most complex mechanisms by considering internal water reuse, external wastewater reclamation, and nutrient recycling processes. The detailed structures for different water cycle pattern are presented from the aspects of water quantity, wastewater quality and nutrients flow. With the speed up of urbanization and development of social-economy in China, those three basic patterns are interacting, transforming and upgrading. According to the past experiences and current situations, urban domestic water system (i.e. intermediate level) is the dominant pattern based on indicator of system number or system scale. The metropolitan domestic water system (i.e. senior level) is the idealized model for the future development and management. Current domestic water system management efforts typically fail in China, because the approach is generally narrowly-focused and fragmented. This paper put forward a total-process control framework following the water and pollutants (or nutrients) flows along the dualistic domestic water cycle process. Five key objectives of domestic water cycle system regulation are identified including water use safety, water use equity, water saving, wastewater reduction and nutrient recycling. Comprehensive regulatory framework regarding administrative, economic, technical and social measures is recommended to promote sustainable domestic water usage and demand management. Considering the relatively low affordability in rural area, economic measures should be mainly applied in urban domestic water systems and metropolitan domestic water systems. Engineering or technological measures which are suitable to the three domestic water cycle systems are discussed respectively.

Fluxes of 13 selected pharmaceuticals in the water cycle of Stockholm, Sweden.

PubMed

Wahlberg, C; Björlenius, B; Paxéus, N

2011-01-01

Mass flows of 13 pharmaceutical active ingredients (APIS) found in drinking water were studied in the water cycle of Stockholm. Data were collected by analyzing samples of surface water, raw water and drinking water as well as influents, effluents and sludges from waste water treatment plants (WWTPs) in Stockholm area. A mass balance was performed, based on sold amounts of pharmaceuticals and the measured concentrations in water and sludge. The selected APls were all present in WWTP effluents and the removal rates for many of them were poor. Mass balance calculations showed that the three studied WWTPs in Stockholm release considerable amounts of the selected APIs into the Baltic Sea while the portions ending up in WWTP sludge were significantly lower. The levels of APIs found in drinking water are low at present, but may increase in the future unless the releases from WWTPs in the catchment of Lake Mälären are mitigated.

Threats and opportunities for freshwater conservation under future land use change scenarios in the United States.

PubMed

Martinuzzi, Sebastián; Januchowski-Hartley, Stephanie R; Pracheil, Brenda M; McIntyre, Peter B; Plantinga, Andrew J; Lewis, David J; Radeloff, Volker C

2014-01-01

Freshwater ecosystems provide vital resources for humans and support high levels of biodiversity, yet are severely threatened throughout the world. The expansion of human land uses, such as urban and crop cover, typically degrades water quality and reduces freshwater biodiversity, thereby jeopardizing both biodiversity and ecosystem services. Identifying and mitigating future threats to freshwater ecosystems requires forecasting where land use changes are most likely. Our goal was to evaluate the potential consequences of future land use on freshwater ecosystems in the coterminous United States by comparing alternative scenarios of land use change (2001-2051) with current patterns of freshwater biodiversity and water quality risk. Using an econometric model, each of our land use scenarios projected greater changes in watersheds of the eastern half of the country, where freshwater ecosystems already experience higher stress from human activities. Future urban expansion emerged as a major threat in regions with high freshwater biodiversity (e.g., the Southeast) or severe water quality problems (e.g., the Midwest). Our scenarios reflecting environmentally oriented policies had some positive effects. Subsidizing afforestation for carbon sequestration reduced crop cover and increased natural vegetation in areas that are currently stressed by low water quality, while discouraging urban sprawl diminished urban expansion in areas of high biodiversity. On the other hand, we found that increases in crop commodity prices could lead to increased agricultural threats in areas of high freshwater biodiversity. Our analyses illustrate the potential for policy changes and market factors to influence future land use trends in certain regions of the country, with important consequences for freshwater ecosystems. Successful conservation of aquatic biodiversity and ecosystem services in the United States into the future will require attending to the potential threats and opportunities arising from policies and market changes affecting land use. © 2013 John Wiley & Sons Ltd.

Exploitation of Nanotechnology for the Monitoring of Waterborne Pathogens: State-of-the-Art and Future Research Priorities.

PubMed

Bridle, Helen; Balharry, Dominique; Gaiser, Birgit; Johnston, Helinor

2015-09-15

Contaminated drinking water is one of the most important environmental contributors to the human disease burden. Monitoring of water for the presence of pathogens is an essential part of ensuring drinking water safety. In order to assess water quality it is essential to have methods available to sample and detect the type, level and viability of pathogens in water which are effective, cheap, quick, sensitive, and where possible high throughput. Nanotechnology has the potential to drastically improve the monitoring of waterborne pathogens when compared to conventional approaches. To date, there have been no reviews that outline the applications of nanotechnology in this area despite increasing exploitation of nanotechnology for this purpose. This review is therefore the first overview of the state-of-the-art in the application of nanotechnology to waterborne pathogen sampling and detection schemes. Research in this field has been centered on the use of engineered nanomaterials. The effectiveness and limitations of nanomaterial-based approaches is outlined. A future outlook of the advances that are likely to emerge in this area, as well as recommendations for areas of further research are provided.

Recent trends in water analysis triggering future monitoring of organic micropollutants.

PubMed

Schmidt, Torsten C

2018-03-21

Water analysis has been an important area since the beginning of analytical chemistry. The focus though has shifted substantially: from minerals and the main constituents of water in the time of Carl Remigius Fresenius to a multitude of, in particular, organic compounds at concentrations down to the sub-nanogram per liter level nowadays. This was possible only because of numerous innovations in instrumentation in recent decades, drivers of which are briefly discussed. In addition to the high demands on sensitivity, high throughput by automation and short analysis times are major requirements. In this article, some recent developments in the chemical analysis of organic micropollutants (OMPs) are presented. These include the analysis of priority pollutants in whole water samples, extension of the analytical window, in particular to encompass highly polar compounds, the trend toward more than one separation dimension before mass spectrometric detection, and ways of coping with unknown analytes by suspect and nontarget screening approaches involving high-resolution mass spectrometry. Furthermore, beyond gathering reliable concentration data for many OMPs, the question of the relevance of such data for the aquatic system under scrutiny is becoming ever more important. To that end, effect-based analytics can be used and may become part of future routine monitoring, mostly with a focus on adverse effects of OMPs in specific test systems mimicking environmental impacts. Despite advances in the field of water analysis in recent years, there are still many challenges for further analytical research. Graphical abstract Recent trends in water analysis of organic micropollutants that open new opportunities in future water monitoring. HRMS high-resolution mass spectrometry, PMOC persistent mobile organic compounds.

The Future Security Environment in the Middle East: Conflict, Stability, and Political Change

DTIC Science & Technology

2004-01-01

1990–1997.21 ______________ 19Alan Richards and Nirvikar Singh, “No Easy Exit: Property Rights, Markets, and Ne- gotiations over Water,” Water Resources...fertilizers and pesticides , halved in FY 1991, were to be completely liberalized by FY 1993. Energy prices were to rise to international levels by 1995, rail...nation, and the first (and until 1994, the only) Arab state to have signed a peace treaty with Israel to extract concessions from the United States, the

Columbia River Component Data Gap Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

L. C. Hulstrom

2007-10-23

This Data Gap Analysis report documents the results of a study conducted by Washington Closure Hanford (WCH) to compile and reivew the currently available surface water and sediment data for the Columbia River near and downstream of the Hanford Site. This Data Gap Analysis study was conducted to review the adequacy of the existing surface water and sediment data set from the Columbia River, with specific reference to the use of the data in future site characterization and screening level risk assessments.

Diverse Land Use and the Impact on (Irrigation) Water Quality and Need for Measures — A Case Study of a Norwegian River

PubMed Central

Johannessen, Gro S.; Wennberg, Aina C.; Nesheim, Ingrid; Tryland, Ingun

2015-01-01

Surface water is used for irrigation of food plants all over the World. Such water can be of variable hygienic quality, and can be contaminated from many different sources. The association of contaminated irrigation water with contamination of fresh produce is well established, and many outbreaks of foodborne disease associated with fresh produce consumption have been reported. The objective of the present study was to summarize the data on fecal indicators and selected bacterial pathogens to assess the level of fecal contamination of a Norwegian river used for irrigation in an area which has a high production level of various types of food commodities. Sources for fecal pollution of the river were identified. Measures implemented to reduce discharges from the wastewater sector and agriculture, and potential measures identified for future implementation are presented and discussed in relation to potential benefits and costs. It is important that the users of the water, independent of intended use, are aware of the hygienic quality and the potential interventions that may be applied. Our results suggest that contamination of surface water is a complex web of many factors and that several measures and interventions on different levels are needed to achieve a sound river and safe irrigation. PMID:26090611

A review on bisphenol A occurrences, health effects and treatment process via membrane technology for drinking water.

PubMed

Muhamad, Mimi Suliza; Salim, Mohd Razman; Lau, Woei Jye; Yusop, Zulkifli

2016-06-01

Massive utilization of bisphenol A (BPA) in the industrial production of polycarbonate plastics has led to the occurrence of this compound (at μg/L to ng/L level) in the water treatment plant. Nowadays, the presence of BPA in drinking water sources is a major concern among society because BPA is one of the endocrine disruption compounds (EDCs) that can cause hazard to human health even at extremely low concentration level. Parallel to these issues, membrane technology has emerged as the most feasible treatment process to eliminate this recalcitrant contaminant via physical separation mechanism. This paper reviews the occurrences and effects of BPA toward living organisms as well as the application of membrane technology for their removal in water treatment plant. The potential applications of using polymeric membranes for BPA removal are also discussed. Literature revealed that modifying membrane surface using blending approach is the simple yet effective method to improve membrane properties with respect to BPA removal without compromising water permeability. The regeneration process helps in maintaining the performances of membrane at desired level. The application of large-scale membrane process in treatment plant shows the feasibility of the technology for removing BPA and possible future prospect in water treatment process.

Large-scale modeled contemporary and future water temperature estimates for 10774 Midwestern U.S. Lakes

USGS Publications Warehouse

Winslow, Luke A.; Hansen, Gretchen J. A.; Read, Jordan S.; Notaro, Michael

2017-01-01

Climate change has already influenced lake temperatures globally, but understanding future change is challenging. The response of lakes to changing climate drivers is complex due to the nature of lake-atmosphere coupling, ice cover, and stratification. To better understand the diversity of lake responses to climate change and give managers insight on individual lakes, we modelled daily water temperature profiles for 10,774 lakes in Michigan, Minnesota, and Wisconsin for contemporary (1979–2015) and future (2020–2040 and 2080–2100) time periods with climate models based on the Representative Concentration Pathway 8.5, the worst-case emission scenario. In addition to lake-specific daily simulated temperatures, we derived commonly used, ecologically relevant annual metrics of thermal conditions for each lake. We include all supporting lake-specific model parameters, meteorological drivers, and archived code for the model and derived metric calculations. This unique dataset offers landscape-level insight into the impact of climate change on lakes.

Large-scale modeled contemporary and future water temperature estimates for 10774 Midwestern U.S. Lakes

PubMed Central

Winslow, Luke A.; Hansen, Gretchen J.A.; Read, Jordan S; Notaro, Michael

2017-01-01

Climate change has already influenced lake temperatures globally, but understanding future change is challenging. The response of lakes to changing climate drivers is complex due to the nature of lake-atmosphere coupling, ice cover, and stratification. To better understand the diversity of lake responses to climate change and give managers insight on individual lakes, we modelled daily water temperature profiles for 10,774 lakes in Michigan, Minnesota, and Wisconsin for contemporary (1979–2015) and future (2020–2040 and 2080–2100) time periods with climate models based on the Representative Concentration Pathway 8.5, the worst-case emission scenario. In addition to lake-specific daily simulated temperatures, we derived commonly used, ecologically relevant annual metrics of thermal conditions for each lake. We include all supporting lake-specific model parameters, meteorological drivers, and archived code for the model and derived metric calculations. This unique dataset offers landscape-level insight into the impact of climate change on lakes. PMID:28440790

Large-scale modeled contemporary and future water temperature estimates for 10774 Midwestern U.S. Lakes

NASA Astrophysics Data System (ADS)

Winslow, Luke A.; Hansen, Gretchen J. A.; Read, Jordan S.; Notaro, Michael

2017-04-01

Climate change has already influenced lake temperatures globally, but understanding future change is challenging. The response of lakes to changing climate drivers is complex due to the nature of lake-atmosphere coupling, ice cover, and stratification. To better understand the diversity of lake responses to climate change and give managers insight on individual lakes, we modelled daily water temperature profiles for 10,774 lakes in Michigan, Minnesota, and Wisconsin for contemporary (1979-2015) and future (2020-2040 and 2080-2100) time periods with climate models based on the Representative Concentration Pathway 8.5, the worst-case emission scenario. In addition to lake-specific daily simulated temperatures, we derived commonly used, ecologically relevant annual metrics of thermal conditions for each lake. We include all supporting lake-specific model parameters, meteorological drivers, and archived code for the model and derived metric calculations. This unique dataset offers landscape-level insight into the impact of climate change on lakes.

Water use of a multigenotype poplar short-rotation coppice from tree to stand scale.

PubMed

Bloemen, Jasper; Fichot, Régis; Horemans, Joanna A; Broeckx, Laura S; Verlinden, Melanie S; Zenone, Terenzio; Ceulemans, Reinhart

2017-02-01

Short-rotation coppice (SRC) has great potential for supplying biomass-based heat and energy, but little is known about SRC's ecological footprint, particularly its impact on the water cycle. To this end, we quantified the water use of a commercial scale poplar ( Populus ) SRC plantation in East Flanders (Belgium) at tree and stand level, focusing primarily on the transpiration component. First, we used the AquaCrop model and eddy covariance flux data to analyse the different components of the stand-level water balance for one entire growing season. Transpiration represented 59% of evapotranspiration (ET) at stand scale over the whole year. Measured ET and modelled ET were lower as compared to the ET of reference grassland, suggesting that the SRC only used a limited amount of water. Secondly, we compared leaf area scaled and sapwood area scaled sap flow ( F s ) measurements on individual plants vs. stand scale eddy covariance flux data during a 39-day intensive field campaign in late summer 2011. Daily stem diameter variation (∆ D ) was monitored simultaneously with F s to understand water use strategies for three poplar genotypes. Canopy transpiration based on sapwood area or leaf area scaling was 43.5 and 50.3 mm, respectively, and accounted for 74%, respectively, 86%, of total ecosystem ET measured during the intensive field campaign. Besides differences in growth, the significant intergenotypic differences in daily ∆ D (due to stem shrinkage and swelling) suggested different water use strategies among the three genotypes which were confirmed by the sap flow measurements. Future studies on the prediction of SRC water use, or efforts to enhance the biomass yield of SRC genotypes, should consider intergenotypic differences in transpiration water losses at tree level as well as the SRC water balance at stand level.

A Review of Nitrates in Drinking Water: Maternal Exposure and Adverse Reproductive and Developmental Outcomes

PubMed Central

Manassaram, Deana M.; Backer, Lorraine C.; Moll, Deborah M.

2006-01-01

In this review we present an update on maternal exposure to nitrates in drinking water in relation to possible adverse reproductive and developmental effects, and also discuss nitrates in drinking water in the United States. The current standard for nitrates in drinking water is based on retrospective studies and approximates a level that protects infants from methemoglobinemia, but no safety factor is built into the standard. The current standard applies only to public water systems. Drinking water source was related to nitrate exposure (i.e., private systems water was more likely than community system water to have nitrate levels above the maximum contaminant limit). Animal studies have found adverse reproductive effects resulting from higher doses of nitrate or nitrite. The epidemiologic evidence of a direct exposure–response relationship between drinking water nitrate level and adverse reproductive effect is still not clear. However, some reports have suggested an association between exposure to nitrates in drinking water and spontaneous abortions, intrauterine growth restriction, and various birth defects. Uncertainties in epidemiologic studies include the lack of individual exposure assessment that would rule out confounding of the exposure with some other cause. Nitrates may be just one of the contaminants in drinking water contributing to adverse outcomes. We conclude that the current literature does not provide sufficient evidence of a causal relationship between exposure to nitrates in drinking water and adverse reproductive effects. Future studies incorporating individual exposure assessment about users of private wells—the population most at risk—should be considered. PMID:16507452

Seasonal forecasts of groundwater levels in Lanyang Plain in Taiwan

NASA Astrophysics Data System (ADS)

Chang, Ya-Chi; Lin, Yi-Chiu

2017-04-01

Groundwater plays a critical and important role in world's freshwater resources and it is also an important part of Taiwan's water supply for domestic, agricultural and industrial use. Prolonged dry climatic conditions can induce groundwater drought and may have huge impact on water resources. Therefore, this study utilizes seasonal rainfall forecasts from the Model for Prediction Across Scales (MPAS) to simulate groundwater levels in Lanyang Plain in Taiwan up to three months into future. The MPAS is setup with 120 km uniform grid and the physics schemes including WSM6 micorphysics scheme, Kain-Fritsch cumulus scheme, RRTMG radiation scheme, and YSU planetary boundary layer scheme are used to provide the rainfall forecasts. Results of this study can provide a reference for water resources management to ensure the sustainability of groundwater resources in Lanyang Plain.

Comparative study on change in groundwaters of rural and urban areas in Korea: effects of climate change

NASA Astrophysics Data System (ADS)

Yun, Sang Woong; Seul Kim, Ye; Kim, Dong Hyun; Kim, Ho Chul; Shin, Min Cheol; Park, Jae Yong; Kim, Heejung; Lee, Jin-Yong

2013-04-01

Groundwater occupies a considerable proportion of the world's water resources and is affected by climate change. It is important to understand how water budget responds to future precipitation variability for sustainable management of groundwater resources. In order to evaluate the effects of climate change on groundwater resources in the future, it is necessary to not only collect field data but also predict groundwater change using some groundwater numerical modelling. In this study, a relevant climate change scenario (RCP 4.5) was adopted and Visual MODFLOW was used as a main tool for predicting water budget. The predicted precipitation and air temperature data were obtained from Climate Change Information Center (CCIC) of Korea. By using the data on the scenario from 2011 to 2100, the future water budget was calculated using groundwater numerical modelling for both Wonju (WJ: urban area) and Yanggu (YG: rural area) of Gangwon Province in Korea. The model calibration was done by the groundwater level measured at 10 monitoring wells. For the numerical prediction, the groundwater recharge (WJ: 10.1%, YG: 13.3%) was estimated using watertable fluctuation (WTF) method and a concept of threshold precipitation (WJ: 240.5 mm, YG: 363.8 mm) was applied. Consequently, the water levels in both Wonju and Yanggu showed gradually increasing trends and ranged from 3.0 to 10.8 m, from 0.5 to 1.8 m in 2100, respectively. Under annual precipitation fluctuation on the scenario (2011-2100), water budget IN-OUT value (-0.87~1.07 m3/day) in Wonju city gradually increases while that (-0.73~0.46 m3/day) of Yanggu county does not. However, its annual difference is enlarged with year for both areas. The results indicate that securing groundwater resource and its management will be difficult because of frequent annual change of the groundwater storage. This work was supported by Science High School R&E program (No. C1008804-01-01) and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2012-0002628).

The Sparta aquifer in Arkansas' critical ground-water areas: Response of the aquifer to supplying future water needs

USGS Publications Warehouse

Hays, Phillip D.; Fugitt, D. Todd

1999-01-01

The Sparta aquifer is a confined aquifer of great regional importance that comprises a sequence of unconsolidated sand, silt, and clay units extending across much of eastern and southeastern Arkansas and into adjoining States. Water use from the aquifer has doubled since 1975 and continues to increase, and large water-level declines are occurring in many areas of the aquifer. To focus State attention and resources on the growing problem and to provide a mechanism for locally based education and management, the Arkansas Soil and Water Conservation Commission has designated Critical Ground-Water Areas in some counties (see page 6, ?What is a Critical Ground-Water Area??). Ground-water modeling study results show that the aquifer cannot continue to meet growing water-use demands. Dewatering of the primary producing sands is predicted to occur within 10 years in some areas if current trends continue. The predicted dewatering will cause reduced yields and damage the aquifer. Modeling also shows that a concerted ground-water conservation management plan could enable sustainable use of the aquifer. Water-conservation measures and use of alternative sources that water managers in Union County (an area of high demand and growth in Arkansas' initial five-county Critical Ground-Water Area) think to be realistic options result in considerable recovery in water levels in the aquifer during a 30-year model simulation.

Assessment of groundwater availability in the Northern Atlantic Coastal Plain aquifer system From Long Island, New York, to North Carolina

USGS Publications Warehouse

Masterson, John P.; Pope, Jason P.; Fienen, Michael N.; Monti, Jr., Jack; Nardi, Mark R.; Finkelstein, Jason S.

2016-08-31

Executive SummaryThe U.S. Geological Survey began a multiyear regional assessment of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system in 2010 as part of its ongoing regional assessments of groundwater availability of the principal aquifers of the Nation. The goals of this national assessment are to document effects of human activities on water levels and groundwater storage, explore climate variability effects on the regional water budget, and provide consistent and integrated information that is useful to those who use and manage the groundwater resource. As part of this nationwide assessment, the USGS evaluated available groundwater resources within the NACP aquifer system from Long Island, New York, to northeastern North Carolina.The northern Atlantic Coastal Plain physiographic province depends heavily on groundwater to meet agricultural, industrial, and municipal needs. The groundwater assessment of the NACP aquifer system included an evaluation of how water use has changed over time; this evaluation primarily used groundwater budgets and development of a numerical modeling tool to assess system responses to stresses from future human uses and climate trends.This assessment focused on multiple spatial and temporal scales to examine changes in groundwater pumping, storage, and water levels. The regional scale provides a broad view of the sources and demands on the system with time. The sub-regional scale provides an evaluation of the differing response of the aquifer system across geographic areas allowing for closer examination of the interaction between different aquifers and confining units and the changes in these interactions under pumping and recharge conditions in 2013 and hydrologic stresses as much as 45 years in the future. By focusing on multiple scales, water-resource managers may utilize this study to understand system response to changes as they affect the system as a whole.The NACP aquifer system extends from Long Island to northeastern North Carolina, and includes aquifers primarily within New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. The seaward-dipping sedimentary wedge that underlies the northern Atlantic Coastal Plain physiographic province forms a complex groundwater system. Although the NACP aquifer system is recognized by the U.S. Geological Survey as one of the smallest of the 66 principal aquifer systems in the Nation, it ranks 13th overall in terms of total groundwater withdrawals and is 7th in population served. Despite abundant precipitation [about 45 inches per year (in/yr)], the supply of fresh surface water in this region is limited because many of the surface waters in this area are brackish estuaries, contributing to why many communities in the northern Atlantic Coastal Plain physiographic province rely heavily on groundwater to meet their water needs.Increases in population and changes in land use during the past 100 years have resulted in diverse increased demands for freshwater throughout the northern Atlantic Coastal Plain physiographic province with groundwater serving as a vital source of drinking water for the nearly 20 million people who live in the region. Total groundwater withdrawal in 2013 was estimated to be about 1,300 million gallons per day (Mgal/d) and accounts for about 40 percent of the drinking water supply with the densely populated areas tending to have the highest rates of withdrawals and, therefore, being most susceptible to effects from these withdrawals over time.Water levels in many of the confined aquifers are decreasing by as much as 2 feet per year (ft/yr) in response to extensive development and subsequent increased withdrawals throughout the region. Total water-level decreases (drawdowns) are more than 100 feet (ft) in some aquifers from their predevelopment (before 1900) levels. These drawdowns extend across state lines and under the Chesapeake and Delaware Bays, creating the potential for interstate aquifer management issues. Regional water-resources managers in the northern Atlantic Coastal Plain physiographic province face challenges beyond competing local domestic, industrial, agricultural, and environmental demands for water. Large changes in regional water use have made the State-level management of aquifer resources more difficult because of hydrologic effects that extend beyond State boundaries.The northern Atlantic Coastal Plain physiographic province is underlain by a wedge of unconsolidated to partially consolidated sediments that are typically thousands of feet thick along the coastline with a maximum thickness of about 10,000 ft near the edge of the continental shelf. The NACP aquifer system consists of nine confined aquifers and nine confining units capped by an unconfined surficial aquifer that is bounded laterally from the west by the contact between Coastal Plain sediments and the upland Piedmont bedrock. This aquifer system extends to the east to the limit of the Continental Shelf, however, the boundary between fresh and saline groundwater is considered to be much closer to the shoreline and varies vertically by aquifer.Precipitation over the region for average conditions from 2005 to 2009 is about 61,800 Mgal/d, but about 70 percent of it is lost to evapotranspiration resulting in an inflow of about 19,600 Mgal/d entering the groundwater system as aquifer recharge. Most of this recharge enters the aquifer system and flows through the shallow unconfined aquifer and either discharges to streams or directly to coastal waters without reaching the deep, confined aquifer system. In addition to recharge from precipitation, other sources of water include the return of wastewater from domestic septic systems of about 240 Mgal/d, about 60 Mgal/d of water released from storage in the confined system, and about 30 Mgal/d of lateral inflow at the boundary between freshwater and saltwater in response to pumping for conditions in 2013.The outflow needed to balance the inflows was subdivided between streamflow, discharge to tidal portions of streams, and coastal discharge. The hydrologic budget developed for current [2013] conditions determined that 93 percent of the total outflow was to surface waters with about 70 percent divided evenly between streamflow and shallow coastal discharge and 23 percent as discharge to tidal waters. The remaining 7 percent of the total outflow components include withdrawals from both the surficial and confined aquifers of the groundwater system.The groundwater availability assessment of the NACP aquifer system highlights the importance of analyses at both the regional and local scales to understand how changes in land use, water use, and climate have affected groundwater resources and how these resources may change in the future. The investigation included assessments of the regional changes in water levels and budgets across State lines, the importance of considering storage change in the confining units, the response of the aquifer system to a continuation of current [2013] hydrologic stresses into the future, and the potential effects of climate change and sea-level rise on the aquifer system.The Potomac aquifer group includes two of the most widely used aquifers in the NACP aquifer system, the Potomac-Patapsco and Potomac-Patuxent regional aquifers, providing about 24 percent of the total groundwater used in the region. Withdrawals from large pumping centers in this deep, confined aquifer group have resulted in substantial decreases in water-levels across state lines, particularly between southern Virginia and northeastern North Carolina as well as between southern New Jersey and northern Delaware where water levels in the Potomac-Patapsco aquifer have decreased by as much as 200 ft and 50 ft, respectively from predevelopment to current [2013] conditions. This response in water levels also is reflected in changes in water budgets where, for example, about 20 percent of the total response to pumping in Virginia is met by inducing flow from adjacent States. Understanding and quantifying these hydrologic effects that extend beyond State boundaries is critical for the State- and regional-level management of aquifer resources.The cumulative storage loss from the intervening confining units throughout the entire NACP aquifer system was about 35 percent of the total storage loss from predevelopment to current [2013] conditions. In geographic areas such as Delmarva Peninsula, Maryland, and New Jersey, the water released from storage in the confining units makes up the majority of the total storage release from the groundwater system and is becoming proportionally more important over time as the surficial aquifer approaches equilibrium with respect to pumping and recharge stresses as of 2013.Storage loss from the confining units is of particular concern because, unlike in the sands that comprise the confined aquifers, water removed from the clayey confining unit sediments cannot be replenished as these units gradually compress. This non-recoverable storage loss, if great enough, can result in land subsidence where these units are thick and the release from storage is relatively large and contributes to increased concerns for sea-level rise in areas such as the lower portion of the Chesapeake Bay.Groundwater usage increased dramatically in the NACP aquifer system during post-World War II era from the mid-1940s to early the 1980s, with withdrawals increasing from about 400 Mgal/d to more than 1,300 Mgal/d. Although groundwater withdrawals have been relatively constant since the early 1980s, about half of the total groundwater withdrawn from the NACP aquifer system since 1900 was withdrawn in the past 30 years. An analysis of the response of the groundwater system to a continuation of the current [2013] pumping for an additional 30 years into the future shows that the flow system continues to adjust in terms of changes in water budget components, water levels, and the boundary between freshwater and saltwater as it approaches equilibrium. The largest change in water budget components is the reduction in the amount of water released from storage.Across the entire NACP aquifer system, the reduction of storage release from 7 to 4 percent of the total water budget change is accounted for by reductions in groundwater discharge to streams and coastal waters. Locally, a similar response is calculated for each of the geographic areas except for Virginia where the amount of water released from storage accounts for about 25 percent of the total change in water budget. This finding suggests that the groundwater flow system in Virginia is not approaching equilibrium under the current [2013] stresses and, therefore, water levels will continue to decrease even if the pumping remains constant.An analysis of the change in water levels in the Potomac-Patapsco aquifer as pumping is continued 30 years into the future reveals that the largest decreases in water levels throughout the NACP aquifer system will occur in the southern Virginia and northeastern North Carolina parts of the study area. It is these areas that also see the greatest potential for increased lateral movement of saline groundwater in the deep, confined portion of the groundwater flow system in response to a continuation of the current [2013] pumping rates.The potential effects of long-term climate change and variability on the hydrologic system and availability of water resources in the NACP aquifer system continue to be of serious societal concern. These concerns include the effects of changes in aquifer recharge and in sea-level rise on the groundwater flow system. An assessment of the potential effects of a prolonged drought during current [2013] pumping conditions indicated that the reductions in recharge associated with droughts, including additional irrigation withdrawals required to meet increased crop water demand, have the greatest effects on water levels and streamflows in the surficial aquifer, and changes in water levels in the confined aquifers primarily resulted from the increased withdrawals associated with increased irrigation pumping; this response was most apparent in the Delmarva Peninsula. These results suggest that water levels may not be susceptible to the effects of droughts in the confined aquifers of the NACP aquifer system not used for irrigation, unlike in the unconfined surficial aquifer.A second analysis also was conducted to assess the effects of sea-level rise on the groundwater system throughout the northern Atlantic Coastal Plain physiographic province because recent analyses of the relative rates of sea-level rise along the Atlantic coast indicate that the Mid-Atlantic region represents a hot spot with anomalously higher rates of sea-level rise than observed elsewhere in the United States. Groundwater levels rose from 0 to 3 ft in response to a 3-ft simulated change in sea-level position, with the largest response occurring along the shoreline and away from non-tidal streams. About 37 percent (or 10,000 square miles) of the area of the northern Atlantic Coastal Plain physiographic province may experience about a 0.5-ft or more increase in water levels with the 3-ft increase in sea-level position, whereas about 18 percent (almost 5,000 square miles) of land of the northern Atlantic Coastal Plain physiographic province may experience a 2-ft or more increase in water levels with the 3-ft increase in sea-level position.These increases in the water table are of particular concern in low-lying areas where the unsaturated (vadose) zone is already thin, thus creating concerns for groundwater inundation of subsurface infrastructure, such as basements, septic systems, and subway systems. This increase in the water table also will likely alter the distribution of groundwater discharge to surface-water bodies thus increasing groundwater flow to streams that would have otherwise discharged directly to coastal waters. Throughout the NACP aquifer system, this redistribution of groundwater discharge results in an additional 2 percent of base flow in streams. Although the increases in groundwater discharge to streams (and corresponding decreases in discharge to coastal waters) calculated for the entire NACP aquifer system and its geographic areas represent only a small increase compared with current [2013] conditions, this redistribution of groundwater discharge from the coast to streams locally can alter the delivery of freshwater input to coastal receiving waters and have ecohydrological implications on the sensitive ecosystems which rely on a balance of groundwater discharge and surface-water flow.

Impact of the climate change to shallow groundwater in Baltic artesian basin

NASA Astrophysics Data System (ADS)

Lauva, D.; Bethers, P.; Timuhins, A.; Sennikovs, J.

2012-04-01

The purpose of our work was to find the long term pattern of annual shallow ground water changes in region of Latvia, ground water level modelling for the contemporary climate and future climate scenarios and the model generalization to the Baltic artesian basin (BAB) region. Latvia is located in the middle part of BAB. It occupies about 65'000 square kilometers. BAB territory (480'000 square kilometres) also includes Lithuania, Estonia as well as parts of Poland, Russia, Belarus and the Baltic Sea. Territory of BAB is more than seven times bigger than Latvia. Precipitation and spring snow melt are the main sources of the ground water recharge in BAB territory. The long term pattern of annual shallow ground water changes was extracted from the data of 25 monitoring wells in the territory of Latvia. The main Latvian groundwater level fluctuation regime can be described as a function with two maximums (in spring and late autumn) and two minimums (in winter and late summer). The mathematical model METUL (developed by Latvian University of Agriculture) was chosen for the ground water modelling. It was calibrated on the observations in 25 gauging wells around Latvia. After the calibration we made calculations using data provided by an ensemble of regional climate models, yielding a continuous groundwater table time-series from 1961 to 2100, which were analysed and split into 3 time windows for further analysis: contemporary climate (1961-1990), near future (2021-2050) and far future (2071-2100). The daily average temperature, precipitation and humidity time series were used as METUL forcing parameters. The statistical downscaling method (Sennikovs and Bethers, 2009) was applied for the bias correction of RCM calculated and measured variables. The qualitative differences in future and contemporary annual groundwater regime are expected. The future Latvian annual groundwater cycle according to the RCM climate projection changes to curve with one peak and one drought point. Acknowledgements. This research was supported by the European Social Fund project "Establishment of interdisciplinary scientist group and modelling system for groundwater research" (Project Nr. 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060). Regional climate model data was provided through the ENSEMBLES data archive, funded by the EU FP6 Integrated Project ENSEMBLES (Contract number 505539). Reference: Sennikovs, J., Bethers, U. 2009. Statistical downscaling method of regional climate model results for hydrological modelling. In: Proceedings of 18th World IMACS / MODSIM Congress.

Evaluating international development investments based on ecosystem services impact

NASA Astrophysics Data System (ADS)

Fremier, A. K.; Brauman, K. A.; Mulligan, M.; Chaplin-Kramer, R.; Gordon, L.; Luedeling, E.; Jones, S. K.; DeClerck, F.

2016-12-01

Engineered water-control structures to supply water for agriculture are frequently funded by international development to an effort to improve human wellbeing. Dams, reservoirs, and other forms of water control frequently have negative impacts on other water users; however, their sustainability in the face of climate change and evolving watershed processes have been called into question. Increasingly, planning for and evaluation of investments in water control require integration of these larger scale impacts and dependencies. Ecosystem service approaches can use local to regional scale knowledge to integrate a broader scope of project impacts by quantifying trade-offs in multiple services across proposed development interventions and future scenarios (economic, climate, demographic). Here, we illustrate the role an ecosystem service approach can play in investment decision making to evaluate the impact of small reservoirs on human wellbeing in the Upper Volta Basin of West Africa. Our project has four components: (1) design of a spatially explicit regional-level social-ecological characterization; (2) construction of future scenario analyses for rainfed and irrigated production system interventions; (3) co-design and co-development of benefit sharing mechanisms at the reservoir catchment level and enhancing institutional capacity to implement these mechanisms through training, professional development and targeting tools; and (4) intervention decision analysis to identify benefits, costs and risks associated with decision options. We illustrate how this approach highlights different outcomes than standard cost-benefit analysis focused narrowly on the single project. Anticipated outcomes are development of ecosystem services-based methods for more equitably and sustainably evaluating development interventions and identifying management approaches to water-impoundment structures that promote a range of ecosystem services to provide food security to a broader population.

Intermittent Surface Water Connectivity: Fill and Spill vs. Fill ...

EPA Pesticide Factsheets

Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining difference in responses was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes. Under the Safe and Sustainable Water Resources National Program, work is being done to qu

Intermittent Surface Water Connectivity: Fill and Spill Vs. Fill ...

EPA Pesticide Factsheets

Intermittent surface connectivity can influence aquatic systems, since chemical and biotic movements are often associated with water flow. Although often referred to as fill and spill, wetlands also fill and merge. We examined the effects of these connection types on water levels, ion concentrations, and biotic communities of eight prairie pothole wetlands between 1979 and 2015. Fill and spill caused pulsed surface water connections that were limited to periods following spring snow melt. In contrast, two wetlands connected through fill and merge experienced a nearly continuous, 20-year surface water connection and had completely coincident water levels. Fill and spill led to minimal convergence in dissolved ions and macroinvertebrate composition, while these constituents converged under fill and merge. The primary factor determining difference in responses was duration of the surface water connection between wetland pairs. Our findings suggest that investigations into the effects of intermittent surface water connections should not consider these connections generically, but need to address the specific types of connections. In particular, fill and spill promotes external water exports while fill and merge favors internal storage. The behaviors of such intermittent connections will likely be accentuated under a future with more frequent and severe climate extremes. Under the Safe and Sustainable Water Resources National Program, work is being done to qu

Urban water metabolism efficiency assessment: integrated analysis of available and virtual water.

PubMed

Huang, Chu-Long; Vause, Jonathan; Ma, Hwong-Wen; Yu, Chang-Ping

2013-05-01

Resolving the complex environmental problems of water pollution and shortage which occur during urbanization requires the systematic assessment of urban water metabolism efficiency (WME). While previous research has tended to focus on either available or virtual water metabolism, here we argue that the systematic problems arising during urbanization require an integrated assessment of available and virtual WME, using an indicator system based on material flow analysis (MFA) results. Future research should focus on the following areas: 1) analysis of available and virtual water flow patterns and processes through urban districts in different urbanization phases in years with varying amounts of rainfall, and their environmental effects; 2) based on the optimization of social, economic and environmental benefits, establishment of an indicator system for urban WME assessment using MFA results; 3) integrated assessment of available and virtual WME in districts with different urbanization levels, to facilitate study of the interactions between the natural and social water cycles; 4) analysis of mechanisms driving differences in WME between districts with different urbanization levels, and the selection of dominant social and economic driving indicators, especially those impacting water resource consumption. Combinations of these driving indicators could then be used to design efficient water resource metabolism solutions, and integrated management policies for reduced water consumption. Copyright © 2013 Elsevier B.V. All rights reserved.

A model of water and sediment balance as determinants of relative sea level rise in contemporary and future deltas

NASA Astrophysics Data System (ADS)

Tessler, Zachary D.; Vörösmarty, Charles J.; Overeem, Irina; Syvitski, James P. M.

2018-03-01

Modern deltas are dependent on human-mediated freshwater and sediment fluxes. Changes to these fluxes impact delta biogeophysical functioning and affect the long-term sustainability of these landscapes for human and for natural systems. Here we present contemporary estimates of long-term mean sediment balance and relative sea level rise across 46 global deltas. We model scenarios of contemporary and future water resource management schemes and hydropower infrastructure in upstream river basins to explore how changing sediment fluxes impact relative sea level rise in delta systems. Model results show that contemporary sediment fluxes, anthropogenic drivers of land subsidence, and sea level rise result in delta relative sea level rise rates that average 6.8 mm/y. Assessment of impacts of planned and under-construction dams on relative sea level rise rates suggests increases on the order of 1 mm/y in deltas with new upstream construction. Sediment fluxes are estimated to decrease by up to 60% in the Danube and 21% in the Ganges-Brahmaputra-Meghna if all currently planned dams are constructed. Reduced sediment retention on deltas caused by increased river channelization and management has a larger impact, increasing relative sea level rise on average by nearly 2 mm/y. Long-term delta sustainability requires a more complete understanding of how geophysical and anthropogenic change impact delta geomorphology. Local and regional strategies for sustainable delta management that focus on local and regional drivers of change, especially groundwater and hydrocarbon extraction and upstream dam construction, can be highly impactful even in the context of global climate-induced sea level rise.

Forests and future water stress in the Southeast

Treesearch

Stephanie Worley Firley

2009-01-01

How will future water supplies be impacted by a changing climate, an increasing population, and shifting land uses and land cover? Will there be enough water to sustain humans and ecosystems alike? And what can be done to help forests adapt to limited water supplies in the future?

Increasing atmospheric [CO2] from glacial through future levels affects drought tolerance via impacts on leaves, xylem and their integrated function

PubMed Central

Medeiros, Juliana S.; Ward, Joy K.

2013-01-01

Summary Changes in atmospheric carbon dioxide concentration ([CO2]) affect plant carbon/water trade-offs, with implications for drought tolerance. Leaf-level studies often indicate that drought tolerance may increase with rising [CO2], but integrated leaf and xylem responses are not well understood in this respect. In addition, the influence of low [CO2] of the last glacial period on drought tolerance and xylem properties is not well understood.We investigated the interactive effects of a broad range of [CO2] and plant water potentials on leaf function, xylem structure and function and the integration of leaf and xylem function in Phaseolus vulgaris.Elevated [CO2] decreased vessel implosion strength, reduced conduit specific hydraulic conductance, and compromised leaf specific xylem hydraulic conductance under moderate drought. By contrast, at glacial [CO2], transpiration was maintained under moderate drought via greater conduit specific and leaf specific hydraulic conductance in association with increased vessel implosion strength.Our study involving the integration of leaf and xylem responses suggests that increasing [CO2] does not improve drought tolerance. We show that under glacial conditions changes in leaf and xylem properties could increase drought tolerance, while under future conditions greater productivity may only occur when higher water use can be accommodated. PMID:23668237

Carbon dioxide and water vapor production at rest and during exercise. A report on data collection for the Crew and Thermal Systems Division

NASA Technical Reports Server (NTRS)

Lee, Stuart M. C.; Siconolfi, Steven F.

1994-01-01

The current environmental control device in the shuttle uses lithium hydroxide (LiOH) filter canisters to remove carbon dioxide (CO2) from the cabin air, requiring several bulky filter canisters that can only be used once and must be changed frequently. To alleviate a stowage problem and decrease launch weight, the Crew and Thermal Systems Division (CTSD) at the NASA Johnson Space Center has been researching a system to be used on future shuttle missions. This system uses two beds of solid amine material to absorb CO2 and water, later desorbing them to space vacuum. In this way the air scrubbing medium is regenerable and reusable. To identify the efficacy of this regenerable CO2 removal system (RCRS), CTSD began investigations in the shuttle mockup. The purpose of this investigation was to support the CTSD program by determining mean levels of carbon dioxide and water vapor production in normal, healthy males and females age-matched with the astronaut corps. Subjects' responses were measured at rest and during exercise at intensity levels equivalent to normal shuttle operation activities. The results were used to assess the adjustments made to RCRS and are reported as a reference for future investigations in shuttle environmental control.

Future landfill emissions and the effect of final cover installation--a case study.

PubMed

Laner, David; Fellner, Johann; Brunner, Paul H

2011-07-01

Municipal solid waste (MSW) landfills are potential long-term sources of emissions. Hence, they need to be managed after closure until they do not pose a threat to humans or the environment. The case study on the Breitenau MSW landfill was performed to evaluate future emission levels for this site and to illustrate the effect of final cover installation with respect to long-term environmental risks. The methodology was based on a comprehensive assessment of the state of the landfill and included analysis of monitoring data, investigations of landfilled waste, and an evaluation of containment systems. A model to estimate future emission levels was established and site-specific predictions of leachate emissions were presented based on scenario analysis. The results are used to evaluate the future pollution potential of the landfill and to compare different aftercare concepts in view of long-term emissions. As some leachable substances became available for water flow during cover construction due to a change in the water flow pattern of the waste, a substantial increase in leachate concentrations could be observed at the site (e.g. concentrations of chloride increased from 200 to 800 mg/l and of ammonia-nitrogen from 140 to about 500 mg/l). A period of intensive flushing before the final cover installation could have reduced the amount of leachable substances within the landfill body and rapidly decreased the leachate concentrations to 11 mg Cl/l and 79 mg NH(4)-N/l within 50 years. Contrarily, the minimization of water infiltration is associated with leachate concentrations in a high range for centuries (above 400 mg Cl/l and 200 mg NH(4)-N/l) with low concomitant annual emission loads (below 12 kg/year of Cl or 9 kg/year of NH(4)-N, respectively). However, an expected gradual decrease of barrier efficiency over time would be associated with higher emission loads of 50 kg of chloride and 30 kg of ammonia-nitrogen at the maximum, but a faster decrease of leachate concentration levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Secret to Successful Deep-Sea Invasion: Does Low Temperature Hold the Key?

PubMed Central

Smith, Kathryn E.; Thatje, Sven

2012-01-01

There is a general consensus that today’s deep-sea biodiversity has largely resulted from recurrent invasions and speciations occurring through homogenous waters during periods of the Phanerozoic eon. Migrations likely continue today, primarily via isothermal water columns, such as those typical of Polar Regions, but the necessary ecological and physiological adaptations behind them are poorly understood. In an evolutionary context, understanding the adaptations, which allow for colonisation to high-pressure environments, may enable us to predict future events. In this investigation, we examine pressure tolerance during development, in the shallow-water neogastropod Buccinum undatum using thermally acclimated egg masses from temperate and sub-polar regions across the species range. Fossil records indicate neogastropods to have a deep-water origin, suggesting shallow-water species may be likely candidates for re-emergence into the deep sea. Our results show population level differences in physiological thresholds, which indicate low temperature acclimation to increase pressure tolerance. These findings imply this species is capable of deep-sea penetration through isothermal water columns prevailing at high latitudes. This study gives new insight into the fundamentals behind past and future colonisation events. Such knowledge is instrumental to understand better how changes in climate envelopes affect the distribution and radiation of species along latitudinal as well as bathymetric temperature gradients. PMID:23227254

The secret to successful deep-sea invasion: does low temperature hold the key?

PubMed

Smith, Kathryn E; Thatje, Sven

2012-01-01

There is a general consensus that today's deep-sea biodiversity has largely resulted from recurrent invasions and speciations occurring through homogenous waters during periods of the Phanerozoic eon. Migrations likely continue today, primarily via isothermal water columns, such as those typical of Polar Regions, but the necessary ecological and physiological adaptations behind them are poorly understood. In an evolutionary context, understanding the adaptations, which allow for colonisation to high-pressure environments, may enable us to predict future events. In this investigation, we examine pressure tolerance during development, in the shallow-water neogastropod Buccinum undatum using thermally acclimated egg masses from temperate and sub-polar regions across the species range. Fossil records indicate neogastropods to have a deep-water origin, suggesting shallow-water species may be likely candidates for re-emergence into the deep sea. Our results show population level differences in physiological thresholds, which indicate low temperature acclimation to increase pressure tolerance. These findings imply this species is capable of deep-sea penetration through isothermal water columns prevailing at high latitudes. This study gives new insight into the fundamentals behind past and future colonisation events. Such knowledge is instrumental to understand better how changes in climate envelopes affect the distribution and radiation of species along latitudinal as well as bathymetric temperature gradients.

Waterbirds and human-related threats to their conservation in Laguna Cuyutlán, Colima, México.

PubMed

Mellink, Eric; Riojas-López, Mónica

2009-01-01

Laguna Cuyutlán, the only large wetland in a span of 1,150 km along the Pacific coast of Mexico, has been neglected as to its importance for waterbird conservation. At least 25 waterbird species nest there, with some of their colonies being very relevant, and at least 61 waterbird species use the lagoon during their non-breeding season. This lagoon has been subject to several structural modifications, including levees and artificial channels which connect it to the sea, while water supply from continental sources has diminished, although its role has not been assessed yet. Salt extraction and artisanal fishery, the main economic activities, do not seem to pose a threat to waterbirds. Among potential threats to this acquatic ecosystem, are the raw sewage discharges that exist near urban areas, and pesticides from the surrounding agricultural lands might reach the lagoon. Seemingly, the most serious threat comes from waterway development in connection with a re-gasification plant to be built, and planned future port expansion, which could potentially increase water levels and alter important habitats for nesting and foraging. We recommend that: the area be declared an Important Bird Area; the development of the re-gasification plant and future port includes a levee to prevent alterations in water level in the remaining sections of the lagoon; supply of exogenous chemicals and waste products be prevented and monitored; alleged benefits from water interchange between the lagoon and the sea through artificial channels should be re-evaluated; and the role of fresh water supplies to the lagoon should be paid attention to.

Toxicological risk assessment and prioritization of drinking water relevant contaminants of emerging concern.

PubMed

Baken, Kirsten A; Sjerps, Rosa M A; Schriks, Merijn; van Wezel, Annemarie P

2018-06-13

Toxicological risk assessment of contaminants of emerging concern (CEC) in (sources of) drinking water is required to identify potential health risks and prioritize chemicals for abatement or monitoring. In such assessments, concentrations of chemicals in drinking water or sources are compared to either (i) health-based (statutory) drinking water guideline values, (ii) provisional guideline values based on recent toxicity data in absence of drinking water guidelines, or (iii) generic drinking water target values in absence of toxicity data. Here, we performed a toxicological risk assessment for 163 CEC that were selected as relevant for drinking water. This relevance was based on their presence in drinking water and/or groundwater and surface water sources in downstream parts of the Rhine and Meuse, in combination with concentration levels and physicochemical properties. Statutory and provisional drinking water guideline values could be derived from publically available toxicological information for 142 of the CEC. Based on measured concentrations it was concluded that the majority of substances do not occur in concentrations which individually pose an appreciable human health risk. A health concern could however not be excluded for vinylchloride, trichloroethene, bromodichloromethane, aniline, phenol, 2-chlorobenzenamine, mevinphos, 1,4-dioxane, and nitrolotriacetic acid. For part of the selected substances, toxicological risk assessment for drinking water could not be performed since either toxicity data (hazard) or drinking water concentrations (exposure) were lacking. In absence of toxicity data, the Threshold of Toxicological Concern (TTC) approach can be applied for screening level risk assessment. The toxicological information on the selected substances was used to evaluate whether drinking water target values based on existing TTC levels are sufficiently protective for drinking water relevant CEC. Generic drinking water target levels of 37 μg/L for Cramer class I substances and 4 μg/L for Cramer class III substances in drinking water were derived based on these CEC. These levels are in line with previously reported generic drinking water target levels based on original TTC values and are shown to be protective for health effects of the majority of contaminants of emerging concern evaluated in the present study. Since the human health impact of many chemicals appearing in the water cycle has been studied insufficiently, generic drinking water target levels are useful for early warning and prioritization of CEC with unknown toxicity in drinking water and its sources for future monitoring. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact of rehabilitation of Assiut barrage, Nile River, on groundwater rise in urban areas

NASA Astrophysics Data System (ADS)

Dawoud, Mohamed A.; El Arabi, Nahed E.; Khater, Ahmed R.; van Wonderen, Jan

2006-08-01

To make optimum use of the most vital natural resource of Egypt, the River Nile water, a number of regulating structures (in the form of dams and barrages) for control and diversion of the river flow have been constructed in this river since the start of the 20th century. One of these barrages is the Assiut barrage which will require considerable repairs in the near future. The design of the rehabilitation of the barrage includes a headpond with water levels maintained at a level approximately 0.60 m higher than the highest water level in the headpond of the present barrage. This development will cause an increase of the seepage flow from the river towards the adjacent agricultural lands, Assiut Town and villages. The increased head pond level might cause a rise of the groundwater levels and impedance of drainage outflows. The drainage conditions may therefore be adversely affected in the so-called impacted areas which comprise floodplains on both sides of the Nile for about 70 km upstream of the future barrage. A rise in the groundwater table, particularly when high river levels impede drainage, may result in waterlogging and secondary salinization of the soil profile in agricultural areas and increase of groundwater into cellars beneath buildings in the urban areas. In addition, a rise in the groundwater table could have negative impact on existing sanitation facilities, in particular in the areas which are served with septic tanks. The impacts of increasing the headpond level were assessed using a three-dimensional groundwater model. The mechanisms of interactions between the Nile River and the underlying Quaternary aquifer system as they affect the recharge/discharge processes are comprehensively outlined. The model has been calibrated for steady state and transient conditions against historical data from observation wells. The mitigation measures for the groundwater rise in the urban areas have been tested using the calibrated mode.

Assessment of impacts of climate change on surface water availability using coupled SWAT and WEAP models: case of upper Pangani River Basin, Tanzania

NASA Astrophysics Data System (ADS)

Kishiwa, Peter; Nobert, Joel; Kongo, Victor; Ndomba, Preksedis

2018-05-01

This study was designed to investigate the dynamics of current and future surface water availability for different water users in the upper Pangani River Basin under changing climate. A multi-tier modeling technique was used in the study, by coupling the Soil and Water Assessment Tool (SWAT) and Water Evaluation And Planning (WEAP) models, to simulate streamflows under climate change and assess scenarios of future water availability to different socio-economic activities by year 2060. Six common Global Circulation Models (GCMs) from WCRP-CMIP3 with emissions Scenario A2 were selected. These are HadCM3, HadGEM1, ECHAM5, MIROC3.2MED, GFDLCM2.1 and CSIROMK3. They were downscaled by using LARS-WG to station scale. The SWAT model was calibrated with observed data and utilized the LARS-WG outputs to generate future streamflows before being used as input to WEAP model to assess future water availability to different socio-economic activities. GCMs results show future rainfall increase in upper Pangani River Basin between 16-18 % in 2050s relative to 1980-1999 periods. Temperature is projected to increase by an average of 2 °C in 2050s, relative to baseline period. Long-term mean streamflows is expected to increase by approximately 10 %. However, future peak flows are estimated to be lower than the prevailing average peak flows. Nevertheless, the overall annual water demand in Pangani basin will increase from 1879.73 Mm3 at present (2011) to 3249.69 Mm3 in the future (2060s), resulting to unmet demand of 1673.8 Mm3 (51.5 %). The impact of future shortage will be more severe in irrigation where 71.12 % of its future demand will be unmet. Future water demands of Hydropower and Livestock will be unmet by 27.47 and 1.41 % respectively. However, future domestic water use will have no shortage. This calls for planning of current and future surface water use in the upper Pangani River Basin.

Simulated effects of ground-water management scenarios on the Santa Fe group aquifer system, Middle Rio Grande Basin, New Mexico, 2001-40

USGS Publications Warehouse

Bexfield, Laura M.; McAda, Douglas P.

2003-01-01

Future conditions in the Santa Fe Group aquifer system through 2040 were simulated using the most recent revision of the U.S. Geological Survey groundwater- flow model for the Middle Rio Grande Basin. Three simulations were performed to investigate the likely effects of different scenarios of future groundwater pumping by the City of Albuquerque on the ground-water system. For simulation I, pumping was held constant at known year-2000 rates. For simulation II, pumping was increased to simulate the use of pumping to meet all projected city water demand through 2040. For simulation III, pumpingwas reduced in accordance with a plan by the City of Albuquerque to use surfacewater to meet most of the projectedwater demand. The simulations indicate that for each of the three pumping scenarios, substantial additional watertable declines would occur in some areas of the basin through 2040. However, the reduced pumping scenario of simulation III also results in water-table rise over a broad area of the city. All three scenarios indicate that the contributions of aquifer storage and river leakage to the ground-water system would change between 2000 and 2040. Comparisons among the results for simulations I, II, and III indicate that the various pumping scenarios have substantially different effects on water-level declines in the Albuquerque area and on the contribution of each water-budget component to the total budget for the ground-water system. Between 2000 and 2040, water-level declines for continued pumping at year-2000 rates are as much as 120 feet greater than for reduced pumping; water-level declines for increased pumping to meet all projected city demand are as much as 160 feet greater. Over the same time period, reduced pumping results in retention in aquifer storage of about 1,536,000 acre-feet of ground water as compared with continued pumping at year- 2000 rates and of about 2,257,000 acre-feet as compared with increased pumping. The quantity of water retained in the Rio Grande as a result of reduced pumping and the associated decrease in induced recharge from the river is about 731,000 acre-feet as compared with continued pumping at year-2000 rates and about 872,000 acre-feet as compared with increased pumping. Reduced pumping results in slight increases in the quantity of water lost from the groundwater system to evapotranspiration and agriculturaldrain flow compared with the other pumping scenarios.

Southern Ocean bottom water characteristics in CMIP5 models

NASA Astrophysics Data System (ADS)

Heuzé, CéLine; Heywood, Karen J.; Stevens, David P.; Ridley, Jeff K.

2013-04-01

Southern Ocean deep water properties and formation processes in climate models are indicative of their capability to simulate future climate, heat and carbon uptake, and sea level rise. Southern Ocean temperature and density averaged over 1986-2005 from 15 CMIP5 (Coupled Model Intercomparison Project Phase 5) climate models are compared with an observed climatology, focusing on bottom water. Bottom properties are reasonably accurate for half the models. Ten models create dense water on the Antarctic shelf, but it mixes with lighter water and is not exported as bottom water as in reality. Instead, most models create deep water by open ocean deep convection, a process occurring rarely in reality. Models with extensive deep convection are those with strong seasonality in sea ice. Optimum bottom properties occur in models with deep convection in the Weddell and Ross Gyres. Bottom Water formation processes are poorly represented in ocean models and are a key challenge for improving climate predictions.

Low-level arsenic exposure from drinking water is associated with prostate cancer in Iowa.

PubMed

Roh, Taehyun; Lynch, Charles F; Weyer, Peter; Wang, Kai; Kelly, Kevin M; Ludewig, Gabriele

2017-11-01

Inorganic arsenic is a toxic naturally occurring element in soil and water in many regions of the US including the Midwest. Prostate cancer is the second most common type of cancer in men in Iowa, surpassed only by non-melanotic skin cancer. Epidemiology studies have evaluated arsenic exposure from drinking water and prostate cancer, but most have focused on high-level exposures outside the US. As drinking water from groundwater sources is a major source of arsenic exposure, we conducted an ecologic study to evaluate prostate cancer and arsenic in drinking water from public water sources and private wells in Iowa, where exposure levels are low, but duration of exposure can be long. Arsenic data from public water systems were obtained from the Iowa Safe Drinking Water Information System for the years 1994-2003 and for private wells from two Iowa Well Water Studies, the Iowa Community Private Well Study (ICPWS, 2002-2003) and Iowa Statewide Rural Well Water Survey Phase 2 (SWIRL2, 2006-2008) that provided data for 87 Iowa counties. Prostate cancer incidence data from 2009 to 2013 for Iowa were obtained from Surveillance, Epidemiology and End Results' SEER*Stat software. County averages of water arsenic levels varied from 1.08 to 18.6 ppb, with three counties above the current 10 ppb limit. Based on the tertiles of arsenic levels, counties were divided into three groups: low (1.08-2.06 ppb), medium (2.07-2.98 ppb), and high (2.99-18.6 ppb). Spatial Poisson regression modeling was conducted to estimate the risk ratios (RR) of prostate cancer by tertiles of arsenic level at a county level, adjusted for demographic and risk factors. The RR of prostate cancer were 1.23 (95% CI, 1.16-1.30) and 1.28 (95% CI, 1.21-1.35) in the medium and high groups, respectively, compared to the low group after adjusting for risk factors. The RR increased to 1.36 (95% CI, 1.28-1.45) in the high group when analyses were restricted to aggressive prostate cancers (Gleason score ≥ 7). This study shows a significant dose-dependent association between low-level arsenic exposure and prostate cancer, and if this result is replicated in future individual-level studies, may suggest that 10 ppb is not protective for human health. Copyright © 2017 Elsevier Inc. All rights reserved.

Mercury contamination level and speciation inventory in Lakes Titicaca & Uru-Uru (Bolivia): Current status and future trends.

PubMed

Guédron, S; Point, D; Acha, D; Bouchet, S; Baya, P A; Tessier, E; Monperrus, M; Molina, C I; Groleau, A; Chauvaud, L; Thebault, J; Amice, E; Alanoca, L; Duwig, C; Uzu, G; Lazzaro, X; Bertrand, A; Bertrand, S; Barbraud, C; Delord, K; Gibon, F M; Ibanez, C; Flores, M; Fernandez Saavedra, P; Ezpinoza, M E; Heredia, C; Rocha, F; Zepita, C; Amouroux, D

2017-12-01

Aquatic ecosystems of the Bolivian Altiplano (∼3800 m a.s.l.) are characterized by extreme hydro-climatic constrains (e.g., high UV-radiations and low oxygen) and are under the pressure of increasing anthropogenic activities, unregulated mining, agricultural and urban development. We report here a complete inventory of mercury (Hg) levels and speciation in the water column, atmosphere, sediment and key sentinel organisms (i.e., plankton, fish and birds) of two endorheic Lakes of the same watershed differing with respect to their size, eutrophication and contamination levels. Total Hg (THg) and monomethylmercury (MMHg) concentrations in filtered water and sediment of Lake Titicaca are in the lowest range of reported levels in other large lakes worldwide. Downstream, Hg levels are 3-10 times higher in the shallow eutrophic Lake Uru-Uru than in Lake Titicaca due to high Hg inputs from the surrounding mining region. High percentages of MMHg were found in the filtered and unfiltered water rising up from <1 to ∼50% THg from the oligo/hetero-trophic Lake Titicaca to the eutrophic Lake Uru-Uru. Such high %MMHg is explained by a high in situ MMHg production in relation to the sulfate rich substrate, the low oxygen levels of the water column, and the stabilization of MMHg due to abundant ligands present in these alkaline waters. Differences in MMHg concentrations in water and sediments compartments between Lake Titicaca and Uru-Uru were found to mirror the offset in MMHg levels that also exist in their respective food webs. This suggests that in situ MMHg baseline production is likely the main factor controlling MMHg levels in fish species consumed by the local population. Finally, the increase of anthropogenic pressure in Lake Titicaca may probably enhance eutrophication processes which favor MMHg production and thus accumulation in water and biota. Copyright © 2017 Elsevier Ltd. All rights reserved.

Estimating the number of cases of acute gastrointestinal illness (AGI) associated with Canadian municipal drinking water systems.

PubMed

Murphy, H M; Thomas, M K; Medeiros, D T; McFADYEN, S; Pintar, K D M

2016-05-01

The estimated burden of endemic acute gastrointestinal illness (AGI) annually in Canada is 20·5 million cases. Approximately 4 million of these cases are domestically acquired and foodborne, yet the proportion of waterborne cases is unknown. A number of randomized controlled trials have been completed to estimate the influence of tap water from municipal drinking water plants on the burden of AGI. In Canada, 83% of the population (28 521 761 people) consumes tap water from municipal drinking water plants serving >1000 people. The drinking water-related AGI burden associated with the consumption of water from these systems in Canada is unknown. The objective of this research was to estimate the number of AGI cases attributable to consumption of drinking water from large municipal water supplies in Canada, using data from four household drinking water intervention trials. Canadian municipal water treatment systems were ranked into four categories based on source water type and quality, population size served, and treatment capability and barriers. The water treatment plants studied in the four household drinking water intervention trials were also ranked according to the aforementioned criteria, and the Canadian treatment plants were then scored against these criteria to develop four AGI risk groups. The proportion of illnesses attributed to distribution system events vs. source water quality/treatment failures was also estimated, to inform the focus of future intervention efforts. It is estimated that 334 966 cases (90% probability interval 183 006-501 026) of AGI per year are associated with the consumption of tap water from municipal systems that serve >1000 people in Canada. This study provides a framework for estimating the burden of waterborne illness at a national level and identifying existing knowledge gaps for future research and surveillance efforts, in Canada and abroad.

Water recycling: a major new initiative for Melbourne--crucial for a sustainable future.

PubMed

Arbon, M; Ireland, M

2003-01-01

Melbourne Water has adopted a challenging target of recycling 20 per cent of treated effluent from Melbourne's two major sewerage treatment plants by 2010. This target was adopted in response to key drivers for water recycling in the Melbourne region such as: strong support for conserving water resources and protecting marine environments; acknowledgment of recycled water as a valuable resource; greater emphasis on environmental issues and sustainable management principles; and opportunities to increase demand for recycled water through effective planning mechanisms. Issues that must be effectively addressed to meet the target include: managing public perceptions of recycled water; health and environmental concerns; lack of consensus among government agencies; high up-front costs of infrastructure; and prices of other sources of water supply not currently true costed. Melbourne Water has identified the following factors as critical in determining the success of recycling strategy: ability to demonstrate that water recycling will be important in terms of long term water cycle management; effective stakeholder consultation; gaining government support; establishing long-term, guaranteed markets for recycled water; implementing well planned, large scale recycling schemes; ability to provide a product that meets customer needs; regulatory approval; and implementation of a system that is economically viable. Water recycling initiatives are being investigated on household, local and regional levels. Over 10 proposals that will contribute to the 20 per cent recycled water target from the regional treatment plants are under various stages of development. Melbourne Water's commitment to recycling within a total water cycle management context is a vital component of this major new initiative for Melbourne and is crucial for a sustainable future.

Drinking Water in Transition: A Multilevel Cross-sectional Analysis of Sachet Water Consumption in Accra.

PubMed

Stoler, Justin; Weeks, John R; Appiah Otoo, Richard

2013-01-01

Rapid population growth in developing cities often outpaces improvements to drinking water supplies, and sub-Saharan Africa as a region has the highest percentage of urban population without piped water access, a figure that continues to grow. Accra, Ghana, implements a rationing system to distribute limited piped water resources within the city, and privately-vended sachet water-sealed single-use plastic sleeves-has filled an important gap in urban drinking water security. This study utilizes household survey data from 2,814 Ghanaian women to analyze the sociodemographic characteristics of those who resort to sachet water as their primary drinking water source. In multilevel analysis, sachet use is statistically significantly associated with lower overall self-reported health, younger age, and living in a lower-class enumeration area. Sachet use is marginally associated with more days of neighborhood water rationing, and significantly associated with the proportion of vegetated land cover. Cross-level interactions between rationing and proxies for poverty are not associated with sachet consumption after adjusting for individual-level sociodemographic, socioeconomic, health, and environmental factors. These findings are generally consistent with two other recent analyses of sachet water in Accra and may indicate a recent transition of sachet consumption from higher to lower socioeconomic classes. Overall, the allure of sachet water displays substantial heterogeneity in Accra and will be an important consideration in planning for future drinking water demand throughout West Africa.

An integrated framework to assess adaptation options to climate change impacts in an irrigated basin in Central North Chile

NASA Astrophysics Data System (ADS)

Vicuna, S.; Melo, O.; Meza, F. J.; Alvarez, P.; Maureira, F.; Sanchez, A.; Tapia, A.; Cortes, M.; Dale, L. L.

2013-12-01

Future climate conditions could potentially affect water supply and demand on water basins throughout the world but especially on snowmelt-driven agriculture oriented basins that can be found throughout central Chile. Increasing temperature and reducing precipitation will affect both the magnitude and timing of water supply this part of the world. Different adaptation strategies could be implemented to reduce the impacts of such scenarios. Some could be incorporated as planned policies decided at the basin or Water Use Organization levels. Examples include changing large scale irrigation infrastructure (reservoirs and main channels) either physically or its operation. Complementing these strategies it is reasonable to think that at a disaggregated level, farmers would also react (adapt) to these new conditions using a mix of options to either modify their patterns of consumption (irrigation efficiency, crop mix, crop area reduction), increase their ability to access new sources of water (groundwater, water markets) or finally compensate their expected losses (insurance). We present a modeling framework developed to represent these issues using as a case study the Limarí basin located in Central Chile. This basin is a renowned example of how the development of reservoirs and irrigation infrastructure can reduce climate vulnerabilities allowing the economic development of a basin. Farmers in this basin tackle climate variability by adopting different strategies that depend first on the reservoir water volume allocation rule, on the type and size of investment they have at their farms and finally their potential access to water markets and other water supplies options. The framework developed can be used to study these strategies under current and future climate scenarios. The cornerstone of the framework is an hydrology and water resources model developed on the WEAP platform. This model is able to reproduce the large scale hydrologic features of the basin such as snowmelt hydrology, reservoir operation and groundwater dynamics. Crop yield under different water irrigation patterns have been inferred using a calibrated Cropsyst model. These crop yields together with user association irrigation constraints are used in a GAMS optimization model embedded dynamically in WEAP in order to obtain every year decisions on crop mix (including fallow land), irrigation patterns and participation in the spot water market. The GAMS optimization model has been calibrated using annual crop mix time series derived using a combination of sources of information ranging from different type of census plus satellite images. The resulting modeling platform is able to simulate under historic and future climate scenarios water availability in different locations of the basin with associated crop yield and economic consequences. The platform also allows the implementation of autonomous and planned adaptation strategies that could reduce the impacts of climate variability and climate change.

Towards a comprehensive and realistic risk evaluation of engineered nanomaterials in the urban water system

NASA Astrophysics Data System (ADS)

Duester, Lars; Burkhardt, Michael; Gutleb, Arno; Kaegi, Ralf; Macken, Ailbhe; Meermann, Björn; von der Kammer, Frank

2014-06-01

The European COoperation in Science and Technology (COST) Action ES1205 on the transfer of Engineered Nano materials from wastewater Treatment and stormwatEr to Rivers (ENTER) aims to create and to maintain a trans European network among scientists. This perspective article delivers a brief overview on the status quo at the beginning of the project by addressing the following aspects on engineered nano materials (ENMs) in the urban systems: i) ENMs that need to be considered on a European level; ii) uncertainties on production-volume estimations; iii) fate of selected ENMs during waste water transport and treatment; iv) analytical strategies for ENM analysis; v) ecotoxicity of ENMs, and vi) future needs. These six step stones deliver the derivation of the position of the ES1205 network at the beginning of the projects runtime, by defining six fundamental aspects that should be considered in future discussions on risk evaluation of ENMs in urban water systems.

Toward a comprehensive and realistic risk evaluation of engineered nanomaterials in the urban water system

PubMed Central

Duester, Lars; Burkhardt, Michael; Gutleb, Arno C.; Kaegi, Ralf; Macken, Ailbhe; Meermann, Björn; von der Kammer, Frank

2014-01-01

The European COoperation in Science and Technology (COST) Action ES1205 on the transfer of Engineered Nano materials from wastewater Treatment and stormwatEr to Rivers (ENTER) aims to create and to maintain a trans European network among scientists. This perspective article delivers a brief overview on the status quo at the beginning of the project by addressing the following aspects on engineered nano materials (ENMs) in the urban systems: (1) ENMs that need to be considered on a European level; (2) uncertainties on production-volume estimations; (3) fate of selected ENMs during waste water transport and treatment; (4) analytical strategies for ENM analysis; (5) ecotoxicity of ENMs, and (6) future needs. These six step stones deliver the derivation of the position of the ES1205 network at the beginning of the projects runtime, by defining six fundamental aspects that should be considered in future discussions on risk evaluation of ENMs in urban water systems. PMID:25003102

Investigating water transport through the xylem network in vascular plants.

PubMed

Kim, Hae Koo; Park, Joonghyuk; Hwang, Ildoo

2014-04-01

Our understanding of physical and physiological mechanisms depends on the development of advanced technologies and tools to prove or re-evaluate established theories, and test new hypotheses. Water flow in land plants is a fascinating phenomenon, a vital component of the water cycle, and essential for life on Earth. The cohesion-tension theory (CTT), formulated more than a century ago and based on the physical properties of water, laid the foundation for our understanding of water transport in vascular plants. Numerous experimental tools have since been developed to evaluate various aspects of the CTT, such as the existence of negative hydrostatic pressure. This review focuses on the evolution of the experimental methods used to study water transport in plants, and summarizes the different ways to investigate the diversity of the xylem network structure and sap flow dynamics in various species. As water transport is documented at different scales, from the level of single conduits to entire plants, it is critical that new results be subjected to systematic cross-validation and that findings based on different organs be integrated at the whole-plant level. We also discuss the functional trade-offs between optimizing hydraulic efficiency and maintaining the safety of the entire transport system. Furthermore, we evaluate future directions in sap flow research and highlight the importance of integrating the combined effects of various levels of hydraulic regulation.

Prediction and assessment of the disturbances of the coal mining in Kailuan to karst groundwater system

NASA Astrophysics Data System (ADS)

Sun, Wenjie; Wu, Qiang; Liu, Honglei; Jiao, Jian

Coal resources and water resources play an essential and strategic role in the development of China's social and economic development, being the priority for China's medium and long technological development. As the mining of the coal extraction is increasingly deep, the mine water inrush of high-pressure confined karst water becomes much more a problem. This paper carried out research on the hundred-year old Kailuan coal mine's karst groundwater system. With the help of advanced Visual Modflow software and numerical simulation method, the paper assessed the flow field of karst water area under large-scale exploitation. It also predicted the evolution ofgroundwaterflow field under different mining schemes of Kailuan Corp. The result shows that two cones of depression are formed in the karst flow field of Zhaogezhuang mining area and Tangshan mining area, and the water levels in two cone centers are -270 m and -31 m respectively, and the groundwater generally flows from the northeast to the southwest. Given some potential closed mines in the future, the mine discharge will decrease and the water level of Ordovician limestone will increase slightly. Conversely, given increase of coal yield, the mine drainage will increase, falling depression cone of Ordovician limestone flow field will enlarge. And in Tangshan's urban district, central water level of the depression cone will move slightly towards north due to pumping of a few mines in the north.

Compilation of geohydrologic data collected as part of the areal appraisal of ground-water resources near Branson, Missouri

USGS Publications Warehouse

Imes, J.L.

1989-01-01

A rapidly developing retirement community and tourist industry in the Branson, Missouri area has created an increased demand for potable water, especially in the summer months. The rapid pace of residential and business expansion has created concerns regarding the future groundwater availability and quality. Water levels measured in the Ozark aquifer during the summer of 1988 and March 1989 show water levels increasing in 22 wells, decreasing in 2 wells, and remaining the same in 1 well. The water level increases ranged from 1 to 111 ft. These measurements and similar measurements during the summer of 1989 will be used to calibrate a three-dimensional model of groundwater flow in the Branson area and estimate the long-term effect of large groundwater withdrawals during the summer tourist season. A reconnaissance of water quality in 34 wells that are open to the Ozark aquifer shows specific conductance ranging from 347 to 841 microsiemens/cm at 25 C and no fecal coliform bacteria present in any well. Chloride and nitrate concentrations in all wells were well below the Missouri Department of Natural Resources recommended maximum concentrations of 250 mg/L and 10 mg/L, respectively. Analysis of 5 water samples for 33 volatile organic compounds failed to detect any concentrations in excess of the detection limits. (USGS)

The water crisis in the gaza strip: prospects for resolution.

PubMed

Weinthal, E; Vengosh, A; Marei, A; Kloppmann, W

2005-01-01

Israel and the Palestinian Authority share the southern Mediterranean coastal aquifer. Long-term overexploitation in the Gaza Strip has resulted in a decreasing water table, accompanied by the degradation of its water quality. Due to high levels of salinity and nitrate and boron pollution, most of the ground water is inadequate for both domestic and agricultural consumption. The rapid rate of population growth in the Gaza Strip and dependence upon ground water as a single water source present a serious challenge for future political stability and economic development. Here, we integrate the results of geochemical studies and numerical modeling to postulate different management scenarios for joint management between Israel and the Palestinian Authority. The chemical and isotopic data show that most of the salinity phenomena in the Gaza Strip are derived from the natural flow of saline ground water from Israel toward the Gaza Strip. As a result, the southern coastal aquifer does not resemble a classic "upstream-downstream" dispute because Israel's pumping of the saline ground water reduces the salinization rates of ground water in the Gaza Strip. Simulation of different pumping scenarios using a monolayer, hydrodynamic, two-dimensional model (MARTHE) confirms the hypothesis that increasing pumping along the Gaza Strip border combined with a moderate reduction of pumping within the Gaza Strip would improve ground water quality within the Gaza Strip. We find that pumping the saline ground water for a source of reverse-osmosis desalination and then supplying the desalinated water to the Gaza Strip should be an essential component of a future joint management strategy between Israel and the Palestinian Authority.

Water-level decline in the Apalachicola River, Florida, from 1954 to 2004, and effects on floodplain habitats

USGS Publications Warehouse

Light, Helen M.; Vincent, Kirk R.; Darst, Melanie R.; Price, Franklin D.

2006-01-01

From 1954 to 2004, water levels declined in the nontidal reach of the Apalachicola River, Florida, as a result of long-term changes in stage-discharge relations. Channel widening and deepening, which occurred throughout much of the river, apparently caused the declines. The period of most rapid channel enlargement began in 1954 and occurred primarily as a gradual erosional process over two to three decades, probably in response to the combined effect of a dam located at the head of the study reach (106 miles upstream from the mouth of the river), river straightening, dredging, and other activities along the river. Widespread recovery has not occurred, but channel conditions in the last decade (1995-2004) have been relatively stable. Future channel changes, if they occur, are expected to be minor. The magnitude and extent of water-level decline attributable to channel changes was determined by comparing pre-dam stage (prior to 1954) and recent stage (1995-2004) in relation to discharge. Long-term stage data for the pre-dam period and recent period from five streamflow gaging stations were related to discharge data from a single gage just downstream from the dam, by using a procedure involving streamflow lag times. The resulting pre-dam and recent stage-discharge relations at the gaging stations were used in combination with low-flow water-surface profile data from the U.S. Army Corps of Engineers to estimate magnitude of water-level decline at closely spaced locations (every 0.1 mile) along the river. The largest water-level declines occurred at the lowest discharges and varied with location along the river. The largest water-level decline, 4.8 feet, which occurred when sediments were scoured from the streambed just downstream from the dam, has been generally known and described previously. This large decline progressively decreased downstream to a magnitude of 1 foot about 40 river miles downstream from the dam, which is the location that probably marks the downstream limit of the influence of the dam on bed scour. Downstream from that location, previously unreported water-level declines progressively increased to 3 feet at a location 68 miles downstream from the dam, probably as a result of various channel modifications conducted in that part of the river. Water-level declines in the river have substantially changed long-term hydrologic conditions in more than 200 miles of off-channel floodplain sloughs, streams, and lakes and in most of the 82,200 acres of floodplain forests in the nontidal reach of the Apalachicola River. Decreases in duration of floodplain inundation at low discharges were large in the upstream-most 10 miles of the river (20-45 percent) and throughout most of the remaining 75 miles of the nontidal reach (10-25 percent). As a consequence of this decreased inundation, the quantity and quality of floodplain habitats for fish, mussels, and other aquatic organisms have declined, and wetland forests of the floodplain are changing in response to drier conditions. Water-level decline caused by channel change is probably the most serious anthropogenic impact that has occurred so far in the Apalachicola River and floodplain. This decline has been exacerbated by long-term reductions in spring and summer flow, especially during drought periods. Although no trends in total annual flow volumes were detected, long-term decreases in discharge for April, May, July, and August were apparent, and water-level declines during drought conditions resulting from decreased discharge in those 4 months were similar in magnitude to the water-level declines caused by channel changes. The observed changes in seasonal discharge are probably caused by a combination of natural climatic changes and anthropogenic activities in the Apalachicola-Chattahoochee-Flint River Basin. Continued research is needed for geomorphic studies to assist in the design of future floodplain restoration efforts and for hydrologic studies to monitor change

Groundwater withdrawal impacts in a karst area

NASA Astrophysics Data System (ADS)

Destephen, R. A.; Benson, C. P.

1993-12-01

During a 3000-gpm pump test on a groundwater supply well in Augusta County, Virginia, residential properties were impacted. The impacts included lowered farm pond water levels, development of a sinkhole, and water level decrease in residential wells. A study was performed to assess whether a lower design yield was possible with minimal impacts on adjacent property. This study included a 48-h 1500-gpm pump test that evaluated impacts due to: (1) sinkhole development and potential damage to homes, (2) loss of water in residential wells, and (3) water-quality degradation. Spring flows, residential well levels, survey monuments, and water quality were monitored. Groundwater and surface water testing included inorganic water-quality parameters and microbiological parameters. The latter included particulate analyses, Giardia cysts, and coliforms, which were used to evaluate the connection between groundwater and local surface waterbodies. Although results of the study indicated a low potential for structural damage due to future sinkhole activity, it showed that the water quality of some residential wells might be degraded. Because particulate analyses confirmed that groundwater into the supply well is under the direct influence of surface water, it was recommended that certain residents be placed on an alternate water supply prior to production pumping and that filtration be provided for the well in accordance with the Surface Water Treatment Rule. A mitigation plan was implemented. This plan included crack surveys, a long-term settlement station monitoring program, and limitation of the groundwater withdrawal rate to 1.0 million gallons per day (mgd) and maximum production rate to 1500 gpm.

Future of Army Water Studies

DTIC Science & Technology

2011-05-01

Energy/ Water Nexus • Thermoelectric power • Geothermal • Biofuels • Solar-hot water • Hydropower • Carbon Capture • “ Fracking ” Regional Water Balance...Future of Army Water Studies Marc Kodack Senior Fellow, Army Environmental Policy Institute/Office of the Deputy Assistant Secretary of the Army...number. 1. REPORT DATE MAY 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE Future of Army Water Studies

Preserving the world second largest hypersaline lake under future irrigation and climate change.

PubMed

Shadkam, Somayeh; Ludwig, Fulco; van Vliet, Michelle T H; Pastor, Amandine; Kabat, Pavel

2016-07-15

Iran Urmia Lake, the world second largest hypersaline lake, has been largely desiccated over the last two decades resulting in socio-environmental consequences similar or even larger than the Aral Sea disaster. To rescue the lake a new water management plan has been proposed, a rapid 40% decline in irrigation water use replacing a former plan which intended to develop reservoirs and irrigation. However, none of these water management plans, which have large socio-economic impacts, have been assessed under future changes in climate and water availability. By adapting a method of environmental flow requirements (EFRs) for hypersaline lakes, we estimated annually 3.7·10(9)m(3) water is needed to preserve Urmia Lake. Then, the Variable Infiltration Capacity (VIC) hydrological model was forced with bias-corrected climate model outputs for both the lowest (RCP2.6) and highest (RCP8.5) greenhouse-gas concentration scenarios to estimate future water availability and impacts of water management strategies. Results showed a 10% decline in future water availability in the basin under RCP2.6 and 27% under RCP8.5. Our results showed that if future climate change is highly limited (RCP2.6) inflow can be just enough to meet the EFRs by implementing the reduction irrigation plan. However, under more rapid climate change scenario (RCP8.5) reducing irrigation water use will not be enough to save the lake and more drastic measures are needed. Our results showed that future water management plans are not robust under climate change in this region. Therefore, an integrated approach of future land-water use planning and climate change adaptation is therefore needed to improve future water security and to reduce the desiccating of this hypersaline lake. Copyright © 2016 Elsevier B.V. All rights reserved.

Changes in Breath Trihalomethane Levels Resulting from Household Water-Use Activities

PubMed Central

Gordon, Sydney M.; Brinkman, Marielle C.; Ashley, David L.; Blount, Benjamin C.; Lyu, Christopher; Masters, John; Singer, Philip C.

2006-01-01

Common household water-use activities such as showering, bathing, drinking, and washing clothes or dishes are potentially important contributors to individual exposure to trihalomethanes (THMs), the major class of disinfection by-products of water treated with chlorine. Previous studies have focused on showering or bathing activities. In this study, we selected 12 common water-use activities and determined which may lead to the greatest THM exposures and result in the greatest increase in the internal dose. Seven subjects performed the various water-use activities in two residences served by water utilities with relatively high and moderate total THM levels. To maintain a consistent exposure environment, the activities, exposure times, air exchange rates, water flows, water temperatures, and extraneous THM emissions to the indoor air were carefully controlled. Water, indoor air, blood, and exhaled-breath samples were collected during each exposure session for each activity, in accordance with a strict, well-defined protocol. Although showering (for 10 min) and bathing (for 14 min), as well as machine washing of clothes and opening mechanical dishwashers at the end of the cycle, resulted in substantial increases in indoor air chloroform concentrations, only showering and bathing caused significant increases in the breath chloroform levels. In the case of bromodichloromethane (BDCM), only bathing yielded a significantly higher air level in relation to the preexposure concentration. For chloroform from showering, strong correlations were observed for indoor air and exhaled breath, blood and exhaled breath, indoor air and blood, and tap water and blood. Only water and breath, and blood and breath were significantly associated for chloroform from bathing. For BDCM, significant correlations were obtained for blood and air, and blood and water from showering. Neither dibromochloromethane nor bromoform gave measurable breath concentrations for any of the activities investigated because of their much lower tap-water concentrations. Future studies will address the effects that changes in these common water-use activities may have on exposure. PMID:16581538

Effect assessment of Future Climate Change on Water Resource and Snow Quality in cold snowy regions in Japan

NASA Astrophysics Data System (ADS)

Taniguchi, Y.; Nakatsugawa, M.; Kudo, K.

2017-12-01

It is predicted that the effects of global warming on everyday life will be clearly seen in cold, snowy regions such as Hokkaido. In relation to climate change, there is the concern that the warmer climate will affect not only water resources, but also local economies, in snowy areas, when air temperature increases and snowfall decreases become more marked in the future. Communities whose economies are greatly dependent on snow as a tourism resource, such as for winter sports and snow events, will lose large numbers of visitors because of the shortened winter season. This study was done as a basic study to provide basic ideas for planning adaptation strategies against climate change based on the local characteristics of a cold, snowy region. By taking dam catchment basins in Hokkaido as the subject areas and by using the climate change prediction data that correspond to IPCCAR5, the local-level influence of future climate change on snowfall and snow quality in relation to water resources and winter sports was quantitatively assessed. The water budget was examined for a dam catchment basin in Hokkaido under the present climate (September 1984 to August 2004) and under the future climate (September 2080 to August 2100) by using rainfall, snowfall and evapotranspiration estimated by the LoHAS heat and water balance analysis model.The examination found that, under the future climate, the net annual precipitation will decrease by up to 200 mm because of decreases in precipitation and in runoff height that will result from increased evapotranspiration. The predicted decrease in annual hydro potential of snowfall was considered to greatly affect the dam reservoir operation during the snowmelt season. The snow quality analysis by SNOWPACK revealed that the future snow would become granular earlier than it does at present. Most skiers' snow preferences, from best to worst, are light dry snow (i.e., fresh snow), lightly compacted snow, compacted snow and, finally, granular snow. If the late-season snow on the slope becomes granular earlier than it has in previous years, then the ski resort's snow conditions will deteriorate. Businesses that receive economic benefits from snow have developed in cold, snowy areas. This study demonstrates that the economic benefits of snow are expected to be greatly reduced by future climate change.

Estimated 2012 groundwater potentiometric surface and drawdown from predevelopment to 2012 in the Santa Fe Group aquifer system in the Albuquerque metropolitan area, central New Mexico

USGS Publications Warehouse

Powell, Rachel I.; McKean, Sarah E.

2014-01-01

Historically, the water-supply requirements of the Albuquerque metropolitan area of central New Mexico were met almost exclusively by groundwater withdrawal from the Santa Fe Group aquifer system. In response to water-level declines, the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began diverting water from the San Juan-Chama Drinking Water Project in December 2008 to reduce the use of groundwater to meet municipal demand. Modifications in the demand for water and the source of the supply of water for the Albuquerque metropolitan area have resulted in a variable response in the potentiometric surface of the production zone (the interval of the aquifer, from within about 200 feet below the water table to 900 feet or more, in which supply wells generally are screened) of the Santa Fe Group aquifer system. Analysis of the magnitude and spatial distribution of water-level change can help improve the understanding of how the groundwater system responds to withdrawals and variations in the management of the water supply and can support water-management agencies’ efforts to minimize future water-level declines and improve sustainability. The U.S. Geological Survey (USGS), in cooperation with the ABCWUA, has developed an estimate of the 2012 potentiometric surface of the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. This potentiometric surface is the latest in a series of reports depicting the potentiometric surface of the area. This report presents the estimated potentiometric surface during winter (from December to March) of water year 2012 and the estimated changes in potentiometric surface between predevelopment (pre-1961) and water year 2012 for the production zone of the Santa Fe Group aquifer system in the Albuquerque metropolitan area. Hydrographs from selected piezometers are included to provide details of historical water-level changes. In general, water-level measurements used for this report were collected in small-diameter observation wells screened over short intervals near the middle of the production zone and were considered to best represent the potentiometric head in the production zone. The water-level measurements were collected by various local and Federal agencies. The water year 2012 potentiometric surface map was created in a geographic information system, and the change in water-level altitude from predevelopment to water year 2012 was calculated. The 2012 potentiometric surface indicates that the general direction of groundwater flow is from the Rio Grande towards clusters of supply wells in the east, north, and west. Water-level changes from predevelopment to 2012 were variable across the Albuquerque metropolitan area. Estimated drawdown from 2008 was spatially variable across the Albuquerque metropolitan area. Hydrographs from piezometers on the east side of the river indicate an increase in the annual highest water-level measurement from 2008 to 2012. Hydrographs from piezometers in the northwest part of the study area indicate either steady decline of the water-level altitude over the period of record or recently variable trends in which water-level altitudes increased for a number of years but have declined since water year 2012.

Effect of water deprivation on baseline and stress-induced corticosterone levels in the Children's python (Antaresia childreni).

PubMed

Dupoué, Andréaz; Angelier, Frédéric; Lourdais, Olivier; Bonnet, Xavier; Brischoux, François

2014-02-01

Corticosterone (CORT) secretion is influenced by endogenous factors (e.g., physiological status) and environmental stressors (e.g., ambient temperature). Heretofore, the impact of water deprivation on CORT plasma levels has not been thoroughly investigated. However, both baseline CORT and stress-induced CORT are expected to respond to water deprivation not only because of hydric stress per se, but also because CORT is an important mineralocorticoid in vertebrates. We assessed the effects of water deprivation on baseline CORT and stress-induced CORT, in Children's pythons (Antaresia childreni), a species that experiences seasonal droughts in natural conditions. We imposed a 52-day water deprivation on a group of unfed Children's pythons (i.e., water-deprived treatment) and provided water ad libitum to another group (i.e., control treatment). We examined body mass variations throughout the experiment, and baseline CORT and stress-induced CORT at the end of the treatments. Relative body mass loss averaged ~10% in pythons without water, a value 2 to 4 times higher compared to control snakes. Following re-exposition to water, pythons from the water-deprived treatment drank readily and abundantly and attained a body mass similar to pythons from the control treatment. Together, these results suggest a substantial dehydration as a consequence of water deprivation. Interestingly, stress-induced but not baseline CORT level was significantly higher in water-deprived snakes, suggesting that baseline CORT might not respond to this degree of dehydration. Therefore, possible mineralocorticoid role of CORT needs to be clarified in snakes. Because dehydration usually induces adjustments (reduced movements, lowered body temperature) to limit water loss, and decreases locomotor performances, elevated stress-induced CORT in water-deprived snakes might therefore compensate for altered locomotor performances. Future studies should test this hypothesis. Copyright © 2013 Elsevier Inc. All rights reserved.

Catchment scale water resource constraints on UK policies for low-carbon energy system transition

NASA Astrophysics Data System (ADS)

Konadu, D. D.; Fenner, R. A.

2017-12-01

Long-term low-carbon energy transition policy of the UK presents national scale propositions of different low-carbon energy system options that lead to meeting GHG emissions reduction target of 80% on 1990 levels by 2050. Whilst national-scale assessments suggests that water availability may not be a significant constrain on future thermal power generation systems in this pursuit, these analysis fail to capture the appropriate spatial scale where water resource decisions are made, i.e. at the catchment scale. Water is a local resource, which also has significant spatio-temporal regional and national variability, thus any policy-relevant water-energy nexus analysis must be reflective of these characteristics. This presents a critical challenge for policy relevant water-energy nexus analysis. This study seeks to overcome the above challenge by using a linear spatial-downscaling model to allocate nationally projected water-intensive energy system infrastructure/technologies to the catchment level, and estimating the water requirements for the deployment of these technologies. The model is applied to the UK Committee on Climate Change Carbon Budgets to 2030 as a case study. The paper concludes that whilst national-scale analyses show minimal long-term water related impacts, catchment level appraisal of water resource requirements reveal significant constraints in some locations. The approach and results presented in this study thus, highlights the importance of bringing together scientific understanding, data and analysis tools to provide better insights for water-energy nexus decisions at the appropriate spatial scale. This is particularly important for water stressed regions where the water-energy nexus must be analysed at appropriate spatial resolution to capture the full water resource impact of national energy policy.

Critical review: Uncharted waters? The future of the electricity-water nexus.

PubMed

Sanders, Kelly T

2015-01-06

Electricity generation often requires large amounts of water, most notably for cooling thermoelectric power generators and moving hydroelectric turbines. This so-called "electricity-water nexus" has received increasing attention in recent years by governments, nongovernmental organizations, industry, and academics, especially in light of increasing water stress in many regions around the world. Although many analyses have attempted to project the future water requirements of electricity generation, projections vary considerably due to differences in temporal and spatial boundaries, modeling frameworks, and scenario definitions. This manuscript is intended to provide a critical review of recent publications that address the future water requirements of electricity production and define the factors that will moderate the water requirements of the electric grid moving forward to inform future research. The five variables identified include changes in (1) fuel consumption patterns, (2) cooling technology preferences, (3) environmental regulations, (4) ambient climate conditions, and (5) electric grid characteristics. These five factors are analyzed to provide guidance for future research related to the electricity-water nexus.

A national reconnaissance for pharmaceuticals and other organic wastewater contaminants in the United States - II) Untreated drinking water sources

USGS Publications Warehouse

Focazio, M.J.; Kolpin, D.W.; Barnes, K.K.; Furlong, E.T.; Meyer, M.T.; Zaugg, S.D.; Barber, L.B.; Thurman, M.E.

2008-01-01

Sixty-three of the 100 targeted chemicals were detected in at least one water sample. Interestingly, in spite of the low detection levels 60% of the 36 pharmaceuticals (including prescription drugs and antibiotics) analyzed were not detected in any water sample. The five most frequently detected chemicals targeted in surface water were: cholesterol (59%, natural sterol), metolachlor (53%, herbicide), cotinine (51%, nicotine metabolite), β-sitosterol (37%, natural plant sterol), and 1,7-dimethylxanthine (27%, caffeine metabolite); and in ground water: tetrachloroethylene (24%, solvent), carbamazepine (20%, pharmaceutical), bisphenol-A (20%, plasticizer), 1,7-dimethylxanthine (16%, caffeine metabolite), and tri (2-chloroethyl) phosphate (12%, fire retardant). A median of 4 compounds were detected per site indicating that the targeted chemicals generally occur in mixtures (commonly near detection levels) in the environment and likely originate from a variety of animal and human uses and waste sources. These data will help prioritize and determine the need, if any, for future occurrence, fate and transport, and health-effects research for subsets of these chemicals and their degradates most likely to be found in water resources used for drinking water in the United States.

Simulation of Ground-Water Flow and Effects of Ground-Water Irrigation on Base Flow in the Elkhorn and Loup River Basins, Nebraska

USGS Publications Warehouse

Peterson, Steven M.; Stanton, Jennifer S.; Saunders, Amanda T.; Bradley, Jesse R.

2008-01-01

Irrigated agriculture is vital to the livelihood of communities in the Elkhorn and Loup River Basins in Nebraska, and ground water is used to irrigate most of the cropland. Concerns about the sustainability of ground-water and surface-water resources have prompted State and regional agencies to evaluate the cumulative effects of ground-water irrigation in this area. To facilitate understanding of the effects of ground-water irrigation, a numerical computer model was developed to simulate ground-water flow and assess the effects of ground-water irrigation (including ground-water withdrawals, hereinafter referred to as pumpage, and enhanced recharge) on stream base flow. The study area covers approximately 30,800 square miles, and includes the Elkhorn River Basin upstream from Norfolk, Nebraska, and the Loup River Basin upstream from Columbus, Nebraska. The water-table aquifer consists of Quaternary-age sands and gravels and Tertiary-age silts, sands, and gravels. The simulation was constructed using one layer with 2-mile by 2-mile cell size. Simulations were constructed to represent the ground-water system before 1940 and from 1940 through 2005, and to simulate hypothetical conditions from 2006 through 2045 or 2055. The first simulation represents steady-state conditions of the system before anthropogenic effects, and then simulates the effects of early surface-water development activities and recharge of water leaking from canals during 1895 to 1940. The first simulation ends at 1940 because before that time, very little pumpage for irrigation occurred, but after that time it became increasingly commonplace. The pre-1940 simulation was calibrated against measured water levels and estimated long-term base flow, and the 1940 through 2005 simulation was calibrated against measured water-level changes and estimated long-term base flow. The calibrated 1940 through 2005 simulation was used as the basis for analyzing hypothetical scenarios to evaluate the effects of ground-water irrigation on stream base flow for 1940 through 2005 and for 2006 through 2045. Simulated base flows were compared for scenarios that alternately did or did not include a representation of the effects of ground-water irrigation. The difference between simulated base flows for the two scenarios represents the predicted effects of ground-water irrigation on base flow. Comparison of base flows between simulations with ground-water irrigation and no ground-water irrigation indicated that ground-water irrigation has cumulatively reduced streamflows from 1940 through 2005 by 888,000 acre-feet in the Elkhorn River Basin and by 2,273,000 acre-feet in the Loup River Basin. Generally, predicted cumulative effects of ground-water irrigation on base flow were 5 to 10 times larger from 2006 through 2045 than from 1940 through 2005, and were 7,678,000 acre-feet for the Elkhorn River Basin and 14,784,000 acre-feet for the Loup River Basin. The calibrated simulation also was used to estimate base-flow depletion as a percentage of pumping volumes for a 50-year future time period, because base-flow depletion percentages are used to guide the placement of management boundaries in Nebraska. Mapped results of the base-flow depletion analysis conducted for most of the interior of the study area indicated that pumpage of one additional theoretical well simulated for a future 50-year period generally would result in more than 80 percent depletion when it was located close to the stream, except in areas where depletion was partly offset by reduced ground-water discharge to evapotranspiration in wetland areas. In many areas, depletion for the 50-year future period composed greater than 10 percent of the pumped water volume for theoretical wells placed less than 7 or 8 miles from the stream, though considerable variations existed because of the heterogeneity of the natural system represented in the simulation. For a few streams, predicted future simulated base flows dec

Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change

USGS Publications Warehouse

McCluney, Kevin E.; Belnap, Jayne; Collins, Scott L.; González, Angélica L.; Hagen, Elizabeth M.; Holland, J. Nathaniel; Kotler, Burt P.; Maestre, Fernando T.; Smith, Stanley D.; Wolf, Blair O.

2012-01-01

Species interactions play key roles in linking the responses of populations, communities, and ecosystems to environmental change. For instance, species interactions are an important determinant of the complexity of changes in trophic biomass with variation in resources. Water resources are a major driver of terrestrial ecology and climate change is expected to greatly alter the distribution of this critical resource. While previous studies have documented strong effects of global environmental change on species interactions in general, responses can vary from region to region. Dryland ecosystems occupy more than one-third of the Earth's land mass, are greatly affected by changes in water availability, and are predicted to be hotspots of climate change. Thus, it is imperative to understand the effects of environmental change on these globally significant ecosystems. Here, we review studies of the responses of population-level plant-plant, plant-herbivore, and predator-prey interactions to changes in water availability in dryland environments in order to develop new hypotheses and predictions to guide future research. To help explain patterns of interaction outcomes, we developed a conceptual model that views interaction outcomes as shifting between (1) competition and facilitation (plant-plant), (2) herbivory, neutralism, or mutualism (plant-herbivore), or (3) neutralism and predation (predator-prey), as water availability crosses physiological, behavioural, or population-density thresholds. We link our conceptual model to hypothetical scenarios of current and future water availability to make testable predictions about the influence of changes in water availability on species interactions. We also examine potential implications of our conceptual model for the relative importance of top-down effects and the linearity of patterns of change in trophic biomass with changes in water availability. Finally, we highlight key research needs and some possible broader impacts of our findings. Overall, we hope to stimulate and guide future research that links changes in water availability to patterns of species interactions and the dynamics of populations and communities in dryland ecosystems.

Impact of climate change on irrigation management for olive orchards at southern Spain

NASA Astrophysics Data System (ADS)

Lorite, Ignacio; Gabaldón-Leal, Clara; Santos, Cristina; Belaj, Angjelina; de la Rosa, Raul; Leon, Lorenzo; Ruiz-Ramos, Margarita

2017-04-01

The irrigation management for olive orchards under future weather conditions requires the development of advanced tools for considering specific physiological and phenological components affected by the foreseen changes in climate and atmospheric [CO2]. In this study a new simulation model named AdaptaOlive has been considered to develop controlled deficit irrigation and full irrigation scheduling for the traditional olive orchards located in Andalusia region (southern Spain) under the projected climate generated by an ensemble of 11 climate models from the ENSEMBLES European project corresponding to the SRES A1B scenario. Irrigation requirements, irrigation water productivity (IWP) and net margin (NM) were evaluated for three periods (baseline, near future and far future) and three irrigation strategies (rainfed, RF, controlled deficit irrigation, CDI, and full irrigation, FI). For irrigation requirements, a very limited average increase for far future compared with baseline period was found (2.6 and 1.3%, for CDI and FI, respectively). Equally, when IWP was analyzed, significant increases were identified for both irrigation strategies (77.4 and 72.2%, for CDI and FI, respectively) due to the high simulated increase in yield. Finally, when net margin was analyzed, the irrigation water cost had a key significance. For low water costs FI provided higher net margin values than for CDI. However, for high water costs (expected in the future due to the foreseen reduction in rainfall and the increase of the competence for the available water resources), net margin is reduced significantly, generating a very elevated number of years with negative net margin. All the described results are affected by a high level of uncertainty as the projections from the ensemble of 11 climate models show large spread. Thus, for a representative location within Andalusia region as Baeza, a reduction of irrigation requirements under full irrigation strategy was found for the ensemble mean (equal to 0.5%). However, when the individual projections from the 11 climate models were considered the variation of irrigation requirements for far future compared with baseline period ranged from increases of 8.5% to reductions of 10.7%. This fact demonstrates the necessity to consider ensembles of climate models for identifying averaged impacts and the range of variability of these impacts, quantifying the uncertainty in the estimates related with water management in the future. The study concludes that the promotion of controlled deficit irrigation strategies is an excellent adaptation strategy. However, this strategy must be supported with the enhance of farmers' training by the implementation of local or regional irrigation advisory services.

Land subsidence along the Delta-Mendota Canal in the northern part of the San Joaquin Valley, California, 2003-10

USGS Publications Warehouse

Sneed, Michelle; Brandt, Justin; Solt, Mike

2013-01-01

Extensive groundwater withdrawal from the unconsolidated deposits in the San Joaquin Valley caused widespread aquifer-system compaction and resultant land subsidence from 1926 to 1970—locally exceeding 8.5 meters. The importation of surface water beginning in the early 1950s through the Delta-Mendota Canal and in the early 1970s through the California Aqueduct resulted in decreased pumping, initiation of water-level recovery, and a reduced rate of compaction in some areas of the San Joaquin Valley. However, drought conditions during 1976–77 and 1987–92, and drought conditions and regulatory reductions in surface-water deliveries during 2007–10, decreased surface-water availability, causing pumping to increase, water levels to decline, and renewed compaction. Land subsidence from this compaction has reduced freeboard and flow capacity of the Delta-Mendota Canal, the California Aqueduct, and other canals that deliver irrigation water and transport floodwater. The U.S. Geological Survey, in cooperation with the U.S. Bureau of Reclamation and the San Luis and Delta-Mendota Water Authority, assessed land subsidence in the vicinity of the Delta-Mendota Canal as part of an effort to minimize future subsidence-related damages to the canal. The location, magnitude, and stress regime of land-surface deformation during 2003–10 were determined by using extensometer, Global Positioning System (GPS), Interferometric Synthetic Aperture Radar (InSAR), spirit leveling, and groundwater-level data. Comparison of continuous GPS, shallow extensometer, and groundwater-level data, combined with results from a one-dimensional model, indicated the vast majority of the compaction took place beneath the Corcoran Clay, the primary regional confining unit. Land-surface deformation measurements indicated that much of the northern portion of the Delta-Mendota Canal (Clifton Court Forebay to Check 14) was fairly stable or minimally subsiding on an annual basis; some areas showed seasonal periods of subsidence and of uplift that resulted in little or no longer-term elevation loss. Many groundwater levels in this northern area did not reach historical lows during 2003–10, indicating that deformation in this region was primarily elastic. Although the northern portion of the Delta-Mendota Canal was relatively stable, land-surface deformation measurements indicated the southern portion of the Delta-Mendota Canal (Checks 15–21) subsided as part of a large subsidence feature centered about 15 kilometers northeast of the Delta-Mendota Canal, south of the town of El Nido. Results of InSAR analysis indicated at least 540 millimeters of subsidence near the San Joaquin River and the Eastside Bypass during 2008–10, which is part of a 3,200 square-kilometer area—including the southern part of the Delta-Mendota Canal—affected by 20 millimeters or more of subsidence during the same period. Calculations indicated that the subsidence rate doubled in 2008 in some areas. The GPS surveys done in 2008 and 2010 confirmed the high subsidence rate measured by using InSAR for the same period. Water levels in many shallow and deep wells in this area declined during 2007–10; water levels in many deep wells reached historical lows, indicating that subsidence measured during this period was largely inelastic. InSAR-derived subsidence maps for various periods during 2003–10 showed that the area of maximum active subsidence (that is, the largest rates of subsidence) shifted from its historical (1926–70) location southwest of Mendota to south of El Nido. Continued groundwater-level and land-subsidence monitoring in the San Joaquin Valley is important because (1) regulatory- and drought-related reductions in surface-water deliveries since 1976 have resulted in increased groundwater pumping and associated land subsidence, and (2) land use and associated groundwater pumping continue to change throughout the valley. The availability of surface water remains uncertain; even during record-setting precipitation years, such as 2010–11, water deliveries have fallen short of requests and groundwater pumping was required to meet the irrigation demand. Due to the expected continued demand for irrigation supply water and the limitations and uncertainty of surface-water supplies, groundwater pumping and associated land subsidence is likely to continue in the future. Spatially detailed information on land subsidence is needed to facilitate minimization of future subsidence-related damages to the Delta-Mendota Canal and other infrastructure in the San Joaquin Valley. The integration of subsidence, deformation, and water-level measurements—particularly continuous measurements—enables the analysis of aquifer-system response to increased groundwater pumping, which in turn, enables identification of the preconsolidation head and calculation of aquifer-system storage properties. This information can be used to improve numerical model simulations of groundwater flow and aquifer-system compaction and allow for consideration of land subsidence in the evaluation of water-resource management alternatives.

Operationalising resilience to drought: Multi-layered safety for flooding applied to droughts

NASA Astrophysics Data System (ADS)

Rijke, Jeroen; Smith, Jennifer Vessels; Gersonius, Berry; van Herk, Sebastiaan; Pathirana, Assela; Ashley, Richard; Wong, Tony; Zevenbergen, Chris

2014-11-01

This paper sets out a way of thinking about how to prepare for and respond to droughts in a holistic way using a framework developed for managing floods. It shows how the multi-layered safety (MLS) approach for flood resilience can be utilised in the context of drought in a way that three layers of intervention can be distinguished for operationalising drought resilience: (1) protection against water shortage through augmentation and diversification of water supplies; (2) prevention of damage in case of water shortage through increased efficiency of water use and timely asset maintenance; (3) preparedness for future water shortages through mechanisms to reduce the use of water and adopt innovative water technologies. Application of MLS to the cities of Adelaide, Melbourne and Sydney shows that recent water reforms in these cities were primarily focused on protection measures that aim to reduce the hazard source or exposure to insufficient water supplies. Prevention and preparedness measures could be considered in defining interventions that aim to further increase the drought resilience of these cities. Although further research is needed, the application suggests that MLS can be applied to the context of drought risk management. The MLS framework can be used to classify the suite of plans deployed by a city to manage future drought risks and can be considered a planning tool to identify opportunities for increasing the level of redundancy and hence resilience of the drought risk management system.

Forecasting and Predicting Coastal Local Sea Level as Support for Coastal Zone Management Decisions and Policy Making (Invited)

NASA Astrophysics Data System (ADS)

Plag, H.

2009-12-01

Local Sea Level (LSL) rise is one of the major anticipated impacts of future global warming with potentially devastating consequences, particularly in many low-lying, often subsiding, and densely populated coastal areas. Risk and vulnerability assessments in support of informed decisions ask for predictions of the plausible range of future LSL trajectories as input, while mitigation and adaptation to potentially rapid LSL changes would benefit from a forecasting of LSL changes on decadal time scales. Low-frequency to secular changes in LSL are the result of a number of location-dependent processes including ocean temperature and salinity changes, ocean and atmospheric circulation changes, mass exchange of the oceans with other reservoirs in the water cycle, and vertical land motion. Mass exchange between oceans and the ice sheets, glaciers, and land water storage has the potential to change coastal LSL in many geographical regions. LSL changes in response to mass exchange with land-based ice sheets, glaciers and water storage are spatially variable due to vertical land motion induced by the shifting loads and gravitational effects resulting from both the relocation of surface water mass and the deformation of the solid Earth under the load. As a consequence, close to a melting ice mass LSL will fall significantly and far away increase more than the global average. The so-called sea level equation expresses LSL as a function of current and past mass changes in ice sheets, glaciers, land water storage, and the resulting mass redistribution in the oceans. Predictions of mass-induced LSL changes exhibit significant inter-model differences, which introduce a large uncertainty in the prediction of LSL variations caused by changes in ice sheets, glaciers, and land water storage. Together with uncertainties in other contributions, this uncertainty produces a large range of plausible future LSL trajectories, which hampers the development of reasonable adaptation strategies for the coastal zone. While the sea level equation has been tested extensively in postglacial rebound studies for the viscous (post-mass change) contribution, a thorough validation of the elastic (co-mass change) contribution has yet to be done. Accurate observations of concurrent LSL changes, vertical land motion, and gravity changes required for such a test were missing until very recently. For the validation, new observations of LSL changes, vertical land motion, and gravity changes close to rapidly changing ice sheets and glaciers in Greenland, Svalbard, and other regions, as well as satellite altimetry observations of sea surface height changes and satellite gravity mission observations of mass changes in the hydrosphere are now available. With a validated solution, we will be able to better characterize LSL changes due to mass exchange of the oceans with, in particular, ice sheets and glaciers as an important contribution to the plausible range of future LSL trajectories in coastal zones. The current "error budget" will be assessed, and the impact of the uncertainties in LSL forecasts (on decadal time scales) and long-term projections (century time scales) on adaptation and mitigation strategies will be discussed.

Jordan Water Project: an interdisciplinary evaluation of freshwater vulnerability and security

NASA Astrophysics Data System (ADS)

Gorelick, S.; Yoon, J.; Rajsekhar, D.; Muller, M. F.; Zhang, H.; Gawel, E.; Klauer, B.; Klassert, C. J. A.; Sigel, K.; Thilmant, A.; Avisse, N.; Lachaut, T.; Harou, J. J.; Knox, S.; Selby, P. D.; Mustafa, D.; Talozi, S.; Haddad, Y.; Shamekh, M.

2016-12-01

The Jordan Water Project, part of the Belmont Forum projects, is an interdisciplinary, international research effort focused on evaluation of freshwater security in Jordan, one of the most water-vulnerable countries in the world. The team covers hydrology, water resources systems analysis, economics, policy evaluation, geography, risk and remote sensing analyses, and model platform development. The entire project team communally engaged in construction of an integrated hydroeconomic model for water supply policy evaluation. To represent water demand and allocation behavior at multiple levels of decision making,the model integrates biophysical modules that simulate natural and engineered hydrologic phenomena with human behavioral modules. Hydrologic modules include spatially-distributed groundwater and surface-water models for the major aquifers and watersheds throughout Jordan. For the human modules, we adopt a multi-agent modeling approach to represent decision-making processes. The integrated model was developed in Pynsim, a new open-source, object-oriented platform in Python for network-based water resource systems. We continue to explore the impacts of future scenarios and interventions.This project had tremendous encouragement and data support from Jordan's Ministry of Water and Irrigation. Modeling technology is being transferred through a companion NSF/USAID PEER project awarded toJordan University of Science and Technology. Individual teams have also conducted a range of studies aimed at evaluating Jordanian and transboundary surface water and groundwater systems. Surveys, interviews, and econometric analyses enabled us to better understandthe behavior of urban households, farmers, private water resellers, water use pattern of the commercial sector and irrigation water user associations. We analyzed nationwide spatial and temporal statistical trends in rainfall, developed urban and national comparative metrics to quantify water supply vulnerability, improved remote sensing methods to estimate crop-water use, and evaluated the impacts of climate change on future drought severity.

Water levels in observation wells in Nebraska during 1955

USGS Publications Warehouse

Keech, C.F.

1956-01-01

The objective of the dbservation-well program in Nebraska is to provide an evaluation of the status of the ground-water supplies. Many uses for water-.level data are known but not all potential uses can be forseen. Among the important uses are the following:To indicate the status of ground water in storage or in transit and the availability of supplies.To show the trend of ground-water supplies and the outlook for the future.To estimate or forcast the base flow of streams.To indicate areas in which the water level is approaching too close to the land surface (water-logging) or is receding toward economic limits of lift or tow rd impairment by water of poor quality.To provide long-term vidence for evaluating the effectiveness of land-management and water...0 nservation programs in relation to water conservation actually of ected, and for use in basin or "watershed" studies.To provide longterm ontinuous records to serve as a framework to which short-term records collected during intensive investigation may be related.The water level in an observation well functions as a gage to indicate the position of the water table o The water table is defined as the upper surface of the zone of saturation except where that surface is formed by overlying impermeable materials. The water table is also the boundary between the zone of saturation and the zone of aeration. It is not a level surface but is a sloping surface that has many irregularities, and it often conforms in a general way to the land surface. The irregularities are caused by several factors. In places where the recharge to the ground-water reservoir is exceptionally large, the water-table may rise to form a mound from which the water slowly spreads. Depressions or troughs in the water table indicate places where the ground water is discharging, as along streams that are below the normal level of the water table, or indicate places where water is being withdrawn by wells or vegetation.The several factors that influence the water table vary in fact and amount from time to time because of changes in weather and the water requirements of vegetation and man; thus, the water table is nearly always rising or falling.The fluctuations of the water table are shown by the changes in water levels in wells. Thus, the rate and amount of the fluctuation of the water table can be ascertained by observing the water levels in wells, and the magnitude of the several factors effecting the position of the water table can be interpreted by analyzing the water—level data.Water-level measurements are given, in this report, in feet below the land surface at the well site. Water levels that are above land surface are preceded by a plus (+) sign, whereas those below land surface have no sign but are understood to be minus (-). The words "land-surface datum" are abbreviated "lsd" in tables of this report.The altitude above mean sea level (msl) of the land surface at many of the well sites has been determined and is included in the tables of this report.Lower case letters which appear in the table of water level measurements indicate the following: 6', nearby well pumped recently; f, dry; g, measured by outside agency; and j, frozen.Twenty-.six observation wells in Nebraska are equipped with recording gages. Each recording gage produces a continuous graph of water-level fluctuations in the well. Only the lowest water level on the last day of record in each month, as recorded by the gage, is given in this report; the complete record is on file in the office of the U. S. Geological Survey in Lincoln, Nebr.

Electric portfolio modeling with stochastic water - climate interactions: Implications for co-management of water and electric utilities

NASA Astrophysics Data System (ADS)

Woldeyesus, Tibebe Argaw

Water supply constraints can significantly restrict electric power generation, and such constraints are expected to worsen with future climate change. The overarching goal of this thesis is to incorporate stochastic water-climate interactions into electricity portfolio models and evaluate various pathways for water savings in co-managed water-electric utilities. Colorado Springs Utilities (CSU) is used as a case study to explore the above issues. The thesis consists of three objectives: Characterize seasonality of water withdrawal intensity factors (WWIF) for electric power generation and develop a risk assessment framework due to water shortages; Incorporate water constraints into electricity portfolio models and evaluate the impact of varying capital investments (both power generation and cooling technologies) on water use and greenhouse gas emissions; Compare the unit cost and overall water savings from both water and electric sectors in co-managed utilities to facilitate overall water management. This thesis provided the first discovery and characterization of seasonality of WWIF with distinct summertime and wintertime variations of +/-17% compared to the power plant average (0.64gal/kwh) which itself is found to be significantly higher than the literature average (0.53gal/kwh). Both the streamflow and WWIF are found to be highly correlated with monthly average temperature (r-sq = 89%) and monthly precipitation (r-sq of 38%) enabling stochastic simulation of future WWIF under moderate climate change scenario. Future risk to electric power generation also showed the risk to be underestimated significantly when using either the literature average or the power plant average WWIF. Seasonal variation in WWIF along with seasonality in streamflow, electricity demand and other municipal water demands along with storage are shown to be important factors for more realistic risk estimation. The unlimited investment in power generation and/or cooling technologies is also found to save water and GHG emissions by 68% and 75% respectively at a marginal levelized cost increase of 12%. In contrast, the zero investment scenarios (which optimizes exiting technologies to address water scarcity constraints on power generation) shows 50% water savings and 23% GHG emissions reduction at a relatively high marginal levelized cost increase of 37%. Water saving strategies in electric sector show very high cost of water savings (48,000 and 200,000)/Mgal-year under unlimited investment and zero investment scenarios respectively, but they have greater water saving impacts of 6% to CSU municipal water demand; while the individual water saving strategies from water sector have low cost of water savings ranging from (37-1,500)/Mgal-year but with less than 0.5% water reduction impact to CSU due to their low penetration. On the other hand, use of reclaimed water for power plant cooling systems have shown great water savings of up to 92% against the BAU and cost of water saving from (0-73,000)/Mgal-year when integrated with unlimited investment and zero investment water minimizing scenarios respectively in the electric sector. Overall, cities need to focus primarily on use of reclaimed water and in new generation technologies' investment including cooling system retrofits while focusing on expanding the penetration rate of individual water saving strategies in the water sector.

Chemical and bioanalytical assessments on drinking water treatments by quaternized magnetic microspheres.

PubMed

Shi, Peng; Ma, Rong; Zhou, Qing; Li, Aimin; Wu, Bing; Miao, Yu; Chen, Xun; Zhang, Xuxiang

2015-03-21

This study aimed to compare the toxicity reduction performance of conventional drinking water treatment (CT) and a treatment (NT) with quaternized magnetic microspheres (NDMP) based on chemical analyses. Fluorescence excitation-emission-matrix combined with parallel factor analysis identified four components in source water of different rivers or lake, and the abundance of each component differed greatly among the different samples. Compared with the CT, the NT evidently reduced the concentrations of dissolved organic carbon, adsorbable organic halogens (AOX), bromide and disinfection by-products. Toxicological evaluation indicated that the NT completely eliminated the cytotoxicity, and greatly reduced the genotoxicity and oxidative stress of all raw water. In contrast, the CT increased the cytotoxicity of Taihu Lake and the Zhongshan River water, genotoxicity of Taihu Lake and the Mangshe River water, as well as the levels of superoxide dismutase and malondialdehyde of the Mangshe River water. Correlation analysis indicated that the AOX of the treated samples was significantly correlated with the genotoxicity and glutathione concentration, but exhibited no correlation with either of them for all the samples. As it can effectively reduce pollutant levels and the toxicities of drinking water, NDMP might be widely used for drinking water treatment in future. Copyright © 2014 Elsevier B.V. All rights reserved.

Global implementation of two shared socioeconomic pathways for future sanitation and wastewater flows.

PubMed

van Puijenbroek, P J T M; Bouwman, A F; Beusen, A H W; Lucas, P L

2015-01-01

Households are an important source of nutrient loading to surface water. Sewage systems without or with only primary wastewater treatment are major polluters of surface water. Future emission levels will depend on population growth, urbanisation, increases in income and investments in sanitation, sewage systems and wastewater treatment plants. This study presents the results for two possible shared socioeconomic pathways (SSPs). SSP1 is a scenario that includes improvement of wastewater treatment and SSP3 does not include such improvement, with fewer investments and a higher population growth. The main drivers for the nutrient emission model are population growth, income growth and urbanisation. Under the SSP1 scenario, 5.7 billion people will be connected to a sewage system and for SSP3 this is 5 billion. Nitrogen and phosphorus emissions increase by about 70% under both SSP scenarios, with the largest increase in SSP1. South Asia and Africa have the largest emission increases, in the developed countries decrease the nutrient emissions. The higher emission level poses a risk to ecosystem services.

Analysis of the Transport and Fate of Metals Released From ...

EPA Pesticide Factsheets

This project’s objectives were to provide analysis of water quality following the release of acid mine drainage in the Animas and San Juan Rivers in a timely manner to 1) generate a comprehensive picture of the plume at the river system level, 2) help inform future monitoring efforts and 3) to predict potential secondary effects that could occur from materials that may remain stored within the system. The project focuses on assessing metals contamination during the plume and in the first month following the event. This project’s objectives were to provide analysis of water quality following the release of acid mine drainage from the Gold King Mine in the Animas and San Juan Rivers in a timely manner to 1) generate a comprehensive picture of the plume at the river system level, 2) help inform future monitoring efforts and 3) to predict potential secondary effects that could occur from materials that may remain stored within the system. The project focuses on assessing metals contamination during the plume and in the first month following the event.

A discussion about public health, lead and Legionella pneumophila in drinking water supplies in the United States.

PubMed

Rosen, Michael B; Pokhrel, Lok R; Weir, Mark H

2017-07-15

Lead (Pb) in public drinking water supplies has garnered much attention since the outset of the Flint water crisis. Pb is a known hazard in multiple environmental matrices, exposure from which results in long-term deleterious health effects in humans. This discussion paper aims to provide a succinct account of environmental Pb exposures with a focus on water Pb levels (WLLs) in the United States. It is understood that there is a strong correlation between WLLs and blood Pb levels (BLLs), and the associated health effects. However, within the Flint water crisis, more than water chemistry and Pb exposure occurred. A cascade of regulatory and bureaucratic failures culminated in the Flint water crisis. This paper will discuss pertinent regulations and responses including their limitations after an overview of the public health effects from Pb exposure as well as discussion on our limitations on monitoring and mitigating Pb in tap water. As the Flint water crisis also included increased Legionnares' disease, caused by Legionella pneumophila, this paper will discuss factors influencing L. pneumophila growth. This will highlight the systemic nature of changes to water chemistry and public health impacts. As we critically analyze these important aspects of water research, we offer discussions to stimulate future water quality research from a new and systemic perspective to inform and guide public health decision-making. Copyright © 2017 Elsevier B.V. All rights reserved.

The environmental impact of future coal production and use in the EEC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1983-01-01

The aims of this study are to assess the expected increased levels of coal consumption in the European Community up to the year 2000; to estimate to what extent consumer demand is likely to be met by EEC production; to determine the level of polluting emissions which are likely to derive from changes in coal consumption and production; and finally, to compare the environmental impact of alternative, existing or developing means of coal utilisation. Contents: Conclusions; Future coal supply and demand in the EEC; Environmental consequences of coal production and use; Coal extraction; Transport and storage; Coal combustion: air pollution;more » Coal combustion: water pollution; Pollution from solid wastes; Coal conversion process; Environmental control technology; Bibliography.« less

Detection and measurement of land subsidence using interferometric synthetic aperture radar and Global Positioning System, San Bernardino County, Mojave Desert, California

USGS Publications Warehouse

Sneed, Michelle; Ikehara, Marti E.; Stork, Sylvia V.; Amelung, Falk; Galloway, Devin L.

2003-01-01

Land subsidence associated with ground-water-level declines has been recognized as a potential problem in parts of the Mojave Desert, California. Ground water has been the primary source of domestic, agricultural, and municipal water supplies in the desert since the early 1900s. Pumping of ground water from the Mojave River and Morongo ground-water basins in the southwestern Mojave Desert resulted in water-level declines of more than 30 meters (100 feet) between the 1950s and the 1990s. A Global Positioning System (GPS) survey of a geodetic network was used to determine the location, extent, and magnitude of vertical land-surface changes in Lucerne Valley in the Morongo ground-water basin. The GPS survey was conducted in 1998 to estimate historical elevation changes by comparing GPS-derived elevations with historical elevations (which were available for some of the monuments in the network as early as 1944) and to establish baseline values that can be used for comparisons with future GPS surveys. The GPS measurements indicated that about 600 millimeters (2 feet) [plus or minus 1,500 millimeters (5 feet)] of subsidence occurred at three of the monuments between 1969 and 1998 but that very little to no vertical change in position occurred at seven other monuments in the network. Water levels in the area of subsidence in Lucerne Valley declined about 15 meters (50 feet) during 1970-98. Interferometric synthetic aperture radar (InSAR) methods were used to characterize vertical land-surface changes in the Mojave River and Morongo ground-water basins during various intervals of time between 1992 and 1999. Interferograms, InSAR-generated displacement maps, show that subsidence ranging from 45 to 90 mm (0.15 to 0.3 ft) occurred in four areas of these two ground-water basins--the El Mirage, Lockhart-Harper Lake (dry), Newberry Springs, and Lucerne Valley areas. Some of the InSAR measurements were affected by the earthquakes at Landers and Hector Mine, California, and by atmospheric artifacts. Water-level data were examined for areas undergoing vertical land-surface changes to determine whether the vertical land-surface changes may be related to aquifer-system compaction caused by ground-water-level changes. Temporally relevant water-level data were sparse for some areas, particularly the El Mirage and Lockhart-Harper Lake (dry) areas. Water levels in wells proximate to the subsiding areas generally declined between 1992 and 1999; water levels in some wells proximate to the subsiding areas experienced seasonal periods of declines and recoveries.

Evaluation of water security in Jordan using a multi-agent, hydroeconomic model: Initial model results from the Jordan Water Project

NASA Astrophysics Data System (ADS)

Yoon, J.; Klassert, C. J. A.; Lachaut, T.; Selby, P. D.; Knox, S.; Gorelick, S.; Rajsekhar, D.; Tilmant, A.; Avisse, N.; Harou, J. J.; Medellin-Azuara, J.; Gawel, E.; Klauer, B.; Mustafa, D.; Talozi, S.; Sigel, K.; Zhang, H.

2016-12-01

Our work focuses on development of a multi-agent, hydroeconomic model for water policy evaluation in Jordan. Jordan ranks among the most water-scarce countries in the world, a situation exacerbated due to a recent influx of refugees escaping the ongoing civil war in neighboring Syria. The modular, multi-agent model is used to evaluate interventions for enhancing Jordan's water security, integrating biophysical modules that simulate natural and engineered phenomena with human modules that represent behavior at multiple levels of decision making. The hydrologic modules are developed using spatially-distributed groundwater and surface water models, which are translated into compact simulators for efficient integration into the multi-agent model. For the multi-agent model, we explicitly account for human agency at multiple levels of decision making, with agents representing riparian, management, supplier, and water user groups. Human agents are implemented as autonomous entities in the model that make decisions in relation to one another and in response to hydrologic and socioeconomic conditions. The integrated model is programmed in Python using Pynsim, a generalizable, open-source object-oriented software framework for modeling network-based water resource systems. The modeling time periods include historical (2006-2014) and future (present-2050) time spans. For the historical runs, the model performance is validated against historical data for several observations that reflect the interacting dynamics of both the hydrologic and human components of the system. A historical counterfactual scenario is also constructed to isolate and identify the impacts of the recent Syrian civil war and refugee crisis on Jordan's water system. For the future period, model runs are conducted to evaluate potential supply, demand, and institutional interventions over a wide range of plausible climate and socioeconomic scenarios. In addition, model sensitivity analysis is conducted revealing the hydrologic and human aspects of the system that most strongly influence water security outcomes, providing insight into coupled human-water system dynamics as well as priority areas of focus for continued model improvement.

Future groundwater extraction scenarios for an aquifer in a semiarid environment: case study of Guadalupe Valley Aquifer, Baja California, Northwest Mexico.

PubMed

Campos-Gaytan, Jose Ruben; Kretzschmar, Thomas; Herrera-Oliva, Claudia Soledad

2014-11-01

Semiarid northwestern Mexico presents a growing water demand produced by agricultural and domestic requirements during the last two decades. The community of Guadalupe Valley and the city of Ensenada rely on groundwater pumping from the local aquifer as its sole source of water supply. This dependency has resulted in an imbalance between groundwater pumpage and natural recharge. A two-dimensional groundwater flow model was applied to the Guadalupe Valley Aquifer, which was calibrated and validated for the period 1984-2005. The model analysis verified that groundwater levels in the region are subject to steep declines due to decades of intensive groundwater exploitation for agricultural and domestic purposes. The calibrated model was used to assess the effects of different water management scenarios for the period 2007-2025. If the base case (status quo) scenario continues, groundwater levels are in a continuous drawdown trend. Some wells would run dry by August 2017, and water demand may not be met without incurring in an overdraft. The optimistic scenario implies the achievement of the mean groundwater recharge and discharge. Groundwater level depletion could be stopped and restored. The sustainable scenario implies the reduction of current extraction (up to about 50 %), when groundwater level depletion could be stopped. A reduction in current extraction mitigates water stress in the aquifer but cannot solely reverse declining water tables across the region. The combination of reduced current extraction and an implemented alternative solution (such as groundwater artificial recharge), provides the most effective measure to stabilize and reverse declining groundwater levels while meeting water demands in the region.

Predictive accuracy of a ground-water model--Lessons from a postaudit

USGS Publications Warehouse

Konikow, Leonard F.

1986-01-01

Hydrogeologic studies commonly include the development, calibration, and application of a deterministic simulation model. To help assess the value of using such models to make predictions, a postaudit was conducted on a previously studied area in the Salt River and lower Santa Cruz River basins in central Arizona. A deterministic, distributed-parameter model of the ground-water system in these alluvial basins was calibrated by Anderson (1968) using about 40 years of data (1923–64). The calibrated model was then used to predict future water-level changes during the next 10 years (1965–74). Examination of actual water-level changes in 77 wells from 1965–74 indicates a poor correlation between observed and predicted water-level changes. The differences have a mean of 73 ft that is, predicted declines consistently exceeded those observed and a standard deviation of 47 ft. The bias in the predicted water-level change can be accounted for by the large error in the assumed total pumpage during the prediction period. However, the spatial distribution of errors in predicted water-level change does not correlate with the spatial distribution of errors in pumpage. Consequently, the lack of precision probably is not related only to errors in assumed pumpage, but may indicate the presence of other sources of error in the model, such as the two-dimensional representation of a three-dimensional problem or the lack of consideration of land-subsidence processes. This type of postaudit is a valuable method of verifying a model, and an evaluation of predictive errors can provide an increased understanding of the system and aid in assessing the value of undertaking development of a revised model.

[Aquatic insects and water quality in Peñas Blancas watershed and reservoir].

PubMed

Mora, Meyer Guevara

2011-06-01

The aquatic insects have been used to evaluate water quality of aquatic environments. The population of aquatic insects and the water quality of the area were characterized according to the natural and human alterations present in the study site. During the monthly-survey, pH, DO, temperature, water level, DBO, PO4 and NO3 were measured. Biological indexes (abundance, species richness and the BMWP-CR) were used to evaluate the water quality. No relation between environmental and aquatic insects was detected. Temporal and spatial differences attributed to the flow events (temporal) and the presence of Peñas Blancas reservoir (spatial). In the future, the investigations in Peñas Blancas watershed need to be focused on determining the real influence of the flows, sediment release and the possible water quality degradation because of agriculture activities.

Environmental Management

ScienceCinema

None

2018-01-16

Another key aspect of the NNSS mission is Environmental Management program, which addresses the environmental legacy from historic nuclear weapons related activities while also ensuring the health and safety of present day workers, the public, and the environment as current and future missions are completed. The Area 5 Radioactive Waste Management site receives low-level and mixed low-level waste from some 28 different generators from across the DOE complex in support of the legacy clean-up DOE Environmental Management project. Without this capability, the DOE would not be able to complete the clean up and proper disposition of these wastes. The program includes environmental protection, compliance, and monitoring of the air, water, plants, animals, and cultural resources at the NNSS. Investigation and implementation of appropriate corrective actions to address the contaminated ground water facilities and soils resulting from historic nuclear testing activities, the demolition of abandoned nuclear facilities, as well as installation of ground water wells to identify and monitor the extent of ground water contamination.

129I and its species in the East China Sea: level, distribution, sources and tracing water masses exchange and movement

PubMed Central

Liu, Dan; Hou, Xiaolin; Du, Jinzhou; Zhang, Luyuan; Zhou, Weijian

2016-01-01

Anthropogenic 129I as a long-lived radioisotope of iodine has been considered as an ideal oceanographic tracer due to its high residence time and conservative property in the ocean. Surface water samples collected from the East China Sea (ECS) in August 2013 were analyzed for 129I, 127I and their inorganic chemical species in the first time. The measured 129I/127I ratio is 1–3 orders of magnitude higher than the pre-nuclear level, indicating its dominantly anthropogenic sources. Relatively high 129I levels were observed in the Yangtze River and its estuary, as well as in the southern Yellow Sea, and 129I level in seawater declines towards the ECS shelf. In the open sea, 129I and 127I in surface water exists mainly as iodate, while in Yangtze River estuary and some locations, iodide is dominated. The results indicate that the Fukushima nuclear accident has no detectable effects in the ECS until August 2013. The obtained results are used for investigation of interaction of various water masses and water circulation in the ECS, as well as the marine environment in this region. Meanwhile this work provides essential data for evaluation of the possible influence of the increasing NPPs along the coast of the ECS in the future. PMID:27849026

Late quaternary history and uranium isotopic compositions of ground water discharge deposits, Crater Flat, Nevada

USGS Publications Warehouse

Paces, James B.; Taylor, Emily M.; Bush, Charles

1993-01-01

Three carbonate-rich spring deposits are present near the southern end of Crater Flat, NV, approximately 18 km southwest of the potential high-level waste repository at Yucca Mountain. We have analyzed five samples of carbonate-rich material from two of the deposits for U and Th isotopic compositions. Resulting U-series disequilibrium ages indicate that springs were active at 18 ?? 1, 30 ?? 3, 45 ?? 4 and >70 ka. These ages are consistent with a crude internal stratigraphy at one site. Identical ages for two samples at two separate sites suggest that springs were contemporaneous, at least in part, and were most likely part of the same hydrodynamic system. In addition, initial U isotopic compositions range from 2.8 to 3.8 and strongly suggest that ground water from the regional Tertiary-volcanic aquifer provided the source for these hydrogenic deposits. This interpretation, along with water level data from near-by wells suggest that the water table rose approximately 80 to 115 m above present levels during the late Quaternary and may have fluctuated repeatedly. Current data are insufficient to allow reconstruction of a detailed depositional history, however geochronological data are in good agreement with other paleoclimatic proxy records preserved throughout the region. Since these deposits are down gradient from the potential repository site, the possibility of higher ground water levels in the future dramatically shortens both vertical and lateral ground water pathways and reduces travel times of transported radionuclides to potential discharge sites.

Constraining Glacial Runoff Contributions to Water Resources in the Cordillera Real, Bolivia using Environmental Tracers

NASA Astrophysics Data System (ADS)

Guido, Z.; McIntosh, J. C.; Papuga, S. A.

2013-12-01

Warming temperatures in recent decades have contributed to substantial reductions in glaciers in many mountain regions around the globe, including the South American Andes. Melting of these glaciers taps water resources accumulated in past climates, and the diminishing ice marks a decrease in a nonrenewable water source that begs the question: how will future water supplies be impacted by climate change. Water resource management and climate adaptation efforts can be informed by knowledge of the extent to which glaciers contribute to seasonal streamflows, but remote locations and scant monitoring often limit this quantification. In Bolivia, more than two million people draw water from watersheds fed, in part, by glaciers. The amount to which these glaciers contribute to the water supply, however, is not well constrained. We apply elemental and isotopic tracers in an end-member mixing model to quantify glacial runoff contributions to local water supplies. We present oxygen and deuterium isotopes and major anion concentrations (sulfate and chloride) of shallow groundwater, streams, reservoirs, small arroyos, and glacial runoff. Isotopic and anion mixing models suggest between 45-67% of the water measured in high altitude streams originated from within the glacial footprint during the 2011 wet season, while glacial runoff contributed about 42-53% of the water in reservoirs in the 2012 dry season. Data also show that shallow groundwater is connected to glacial-fed streams. Any future decrease in glacial runoff may contribute to a reduction in surface water supplies and lower groundwater levels downstream, perhaps below the depth of hand-dug wells common in rural communities.

Possible impacts of sea level rise on disease transmission and potential adaptation strategies, a review.

PubMed

Dvorak, Ana C; Solo-Gabriele, Helena M; Galletti, Andrea; Benzecry, Bernardo; Malone, Hannah; Boguszewski, Vicki; Bird, Jason

2018-07-01

Sea levels are projected to rise in response to climate change, causing the intrusion of sea water into land. In flat coastal regions, this would generate an increase in shallow water covered areas with limited circulation. This scenario raises a concern about the consequences it could have on human health, specifically the possible impacts on disease transmission. In this review paper we identified three categories of diseases which are associated with water and whose transmission can be affected by sea level rise. These categories include: mosquitoborne diseases, naturalized organisms (Vibrio spp. and toxic algae), and fecal-oral diseases. For each disease category, we propose comprehensive adaptation strategies that would help minimize possible health risks. Finally, the City of Key West, Florida is analyzed as a case study, due to its inherent vulnerability to sea level rise. Current and projected adaptation techniques are discussed as well as the integration of additional recommendations, focused on disease transmission control. Given that sea level rise will likely continue into the future, the promotion and implementation of positive adaptation strategies is necessary to ensure community resilience. Copyright © 2018 Elsevier Ltd. All rights reserved.

Sensitivity of Water-Energy Nexus to dam operation: A Water-Energy Productivity concept.

PubMed

Basheer, Mohammed; Elagib, Nadir Ahmed

2018-03-01

Understanding and modelling the complex nature of interlinkages between water and energy are essential for efficient use of the two resources. Hydropower storage dams represent an interesting example of the water-energy interdependencies since they are often multipurpose. The concept of Water-Energy Productivity (WEP), defined as the amount of energy produced per unit of water lost in the process, is introduced in this study to illustrate the relationship between energy generation and water losses by examining the sensitivity of the Water-Energy Nexus (WEN) to changing dam operation policy. This concept is demonstrated by developing a water allocation model of the White Nile in Sudan, including Jebel Aulia Dam (JAD), using a general river and reservoir simulation software called RiverWare. A number of 77 operation scenarios of JAD are examined for 30 hydrologic years (1980-2009), considering reducing the Full Supply Level (FSL) gradually from its current value to the minimum possible value, increasing the Minimum Operating Level (MOL) gradually to the maximum possible level, and operating the dam at a Constant Operating Level (COL). The results show that raising the operating level does not necessarily increase the WEP. In comparison to the current policy, the analysis shows that a maximum WEP of 32.6GWh/BCM (GWh/Billion Cubic Meters) would be reached by raising the MOL to 375masl (meters above sea level), resulting in an increase in average annual energy generation to 164.6GWh (+18.1%) at the expense of an annual water loss of 5.05BCM (+12.7%). Even though this operation policy results in a more efficient water use compared to the original operation policy, a basin-wide assessment that includes all hydropower storage dams in the Nile basin should be conducted to decide on where and how much energy should be generated. The present analysis and future examination of the multi-dimensions of the WEN in the context of dam operation are imperative to improve the decision making in the quest for efficient resource use and management. Copyright © 2017 Elsevier B.V. All rights reserved.

Gauging leaf-level contributions to landscape-level water loss within a Western US dryland fores

NASA Astrophysics Data System (ADS)

Murphy, P.; Potts, D. L.; Minor, R. L.; Hamerlynck, E. P.; Sutter, L., Jr.; Barron-Gafford, G.

2017-12-01

Western US forests represent a large constituent of the North American water and carbon cycles, yet the primary controls on water loss from these ecosystems remains unknown. In dryland forests, such as those found in the Southwestern US, water availability is key to ecosystem function, and the timing and magnitude of water loss can have lasting effects on the health of these communities. One poorly defined part of the water balance in these forests is the partitioning of evapotranspiration (ET) into evaporation (E; blue flow) to transpiration (T; green flow). A study of water fluxes at multiple scales in a semiarid montane forest in Southern Arizona speaks to the partitioning of these two water flows. Within the footprint of an eddy covariance system, which estimates ecosystem ET, we have examined the impacts of variation in climate, species makeup, and topographic position on E and T. This was done using leaf-level measures of T, pedon-scale measures of E, and whole-tree water loss by way of sap flux sensors. Where available, we have examined E, T, and ET fluxes across multiple seasons and years of highly variable precipitation records. Understanding the partitioning of ET is crucial, considering that projected changes to dryland ecosystems include longer periods of drought separated by heavier precipitation events. At a moment when potential impacts of changing climate on dryland structure and function are poorly understood, a stronger comprehension of these blue and green water flows is necessary to forecast the productivity of Western US forests into the future.

Evaluation of the groundwater flow model for southern Utah and Goshen Valleys, Utah, updated to conditions through 2011, with new projections and groundwater management simulations

USGS Publications Warehouse

Brooks, Lynette E.

2013-01-01

The U.S. Geological Survey (USGS), in cooperation with the Southern Utah Valley Municipal Water Association, updated an existing USGS model of southern Utah and Goshen Valleys for hydrologic and climatic conditions from 1991 to 2011 and used the model for projection and groundwater management simulations. All model files used in the transient model were updated to be compatible with MODFLOW-2005 and with the additional stress periods. The well and recharge files had the most extensive changes. Discharge to pumping wells in southern Utah and Goshen Valleys was estimated and simulated on an annual basis from 1991 to 2011. Recharge estimates for 1991 to 2011 were included in the updated model by using precipitation, streamflow, canal diversions, and irrigation groundwater withdrawals for each year. The model was evaluated to determine how well it simulates groundwater conditions during recent increased withdrawals and drought, and to determine if the model is adequate for use in future planning. In southern Utah Valley, the magnitude and direction of annual water-level fluctuation simulated by the updated model reasonably match measured water-level changes, but they do not simulate as much decline as was measured in some locations from 2000 to 2002. Both the rapid increase in groundwater withdrawals and the total groundwater withdrawals in southern Utah Valley during this period exceed the variations and magnitudes simulated during the 1949 to 1990 calibration period. It is possible that hydraulic properties may be locally incorrect or that changes, such as land use or irrigation diversions, occurred that are not simulated. In the northern part of Goshen Valley, simulated water-level changes reasonably match measured changes. Farther south, however, simulated declines are much less than measured declines. Land-use changes indicate that groundwater withdrawals in Goshen Valley are possibly greater than estimated and simulated. It is also possible that irrigation methods, amount of diversions, or other factors have changed that are not simulated or that aquifer properties are incorrectly simulated. The model can be used for projections about the effects of future groundwater withdrawals and managed aquifer recharge in southern Utah Valley, but rapid changes in withdrawals and increasing withdrawals dramatically may reduce the accuracy of the predicted water-level and groundwater-budget changes. The model should not be used for projections in Goshen Valley until additional withdrawal and discharge data are collected and the model is recalibrated if necessary. Model projections indicate large drawdowns of up to 400 feet and complete cessation of natural discharge in some areas with potential future increases in water use. Simulated managed aquifer recharge counteracts those effects. Groundwater management examples indicate that drawdown could be less, and discharge at selected springs could be greater, with optimized groundwater withdrawals and managed aquifer recharge than without optimization. Recalibration to more recent stresses and seasonal stress periods, and collection of new withdrawal, stream, land-use, and discharge data could improve the model fit to water-level changes and the accuracy of predictions.

Characterization of groundwater resources in the Trinity and Woodbine aquifers in Texas.

PubMed

Chaudhuri, Sriroop; Ale, Srinivasulu

2013-05-01

A vast region in north-central Texas, centering on Dallas-Fort Worth metroplex, suffers from intense groundwater drawdown and water quality degradation, which led to inclusion of 18 counties of this region into Priority Groundwater Management Areas. We combined aquifer-based and county-based hydrologic analyses to (1) assess spatio-temporal changes in groundwater level and quality between 1960 and 2010 in the Trinity and Woodbine aquifers underlying the study region, (2) delve into major hydrochemical facies with reference to aquifer hydrostratigraphy, and (3) identify county-based spatial zones to aid in future groundwater management initiatives. Water-level and quality data was obtained from the Texas Water Development Board (TWDB) and analyzed on a decadal scale. Progressive water-level decline was the major concern in the Trinity aquifer with >50% of observations occurring at depths >100 m since the 1980s, an observation becoming apparent only in the 2000s in the Woodbine aquifer. Water quality degradation was the major issue in the Woodbine aquifer with substantially higher percentage of observations exceeding the secondary maximum contaminant levels (SMCL; a non-enforceable threshold set by the United State Environmental Protection Agency (USEPA)) and/or maximum contaminant level (MCL, a legally enforceable drinking water standard set by the USEPA) for sulfate (SO4(2-)), chloride (Cl(-)), and fluoride (F(-)) in each decade. In both aquifers, however, >70% of observations exceeded the SMCL for total dissolved solids indicating high groundwater salinization. Water-level changes in Trinity aquifer also had significant negative impact on water quality. Hydrochemical facies in this region sequentially evolved from Ca-Mg-HCO3 and Ca-HCO3 in the fluvial sediments of the west to Na-SO4-Cl in the deltaic sediments to the east. Sequentially evolving hydrogeochemical facies and increasing salinization closely resembled regional groundwater flow pattern. Distinct spatial zones based on homogenous hydrologic characteristics have become increasingly apparent over time indicating necessity of zone-specific groundwater management strategies. Copyright © 2013 Elsevier B.V. All rights reserved.

Leaf to landscape responses of giant sequoia to hotter drought: An introduction and synthesis for the special section

USGS Publications Warehouse

Nydick, Koren R.; Stephenson, Nathan L.; Ambrose, Anthony R.; Asner, Gregory P.; Baxter, Wendy L.; Das, Adrian J.; Dawson, Todd E.; Martin, Roberta E.; Paz-Kagan, Tarin

2018-01-01

Hotter droughts are becoming more common as climate change progresses, and they may already have caused instances of forest dieback on all forested continents. Learning from hotter droughts, including where on the landscape forests are more or less vulnerable to these events, is critical to help resource managers proactively prepare for the future. As part of our Leaf to Landscape Project, we measured the response of giant sequoia, the world’s largest tree species, to the extreme 2012–2016 hotter drought in California. The project integrated leaf-level physiology measurements, crown-level foliage dieback surveys, and remotely sensed canopy water content (CWC) to shed light on mechanisms and spatial patterns in drought response. Here we summarize initial findings, present a conceptual model of drought response, and discuss management implications; details are presented in the other four articles of the special section on Giant Sequoias and Drought. Giant sequoias exhibited both leaf- and canopy-level responses that were effective in protecting whole-tree hydraulic integrity for the vast majority of individual sequoias. Very few giant sequoias died during the drought compared to other mixed conifer tree species; however, the magnitude of sequoia drought response varied across the landscape. This variability was partially explained by local site characteristics, including variables related to site water balance. We found that low CWC is an indicator of recent foliage dieback, which occurs when stress levels are high enough that leaf-level adjustments alone are insufficient for giant sequoias to maintain hydraulic integrity. CWC or change in CWC may be useful indicators of drought stress that reveal patterns of vulnerability to future hotter droughts. Future work will measure recovery from the drought and strengthen our ability to interpret CWC maps. Our ultimate goal is to produce giant sequoia vulnerability maps to help target management actions, such as reducing other stressors, increasing resistance to hotter drought through prescribed fire or mechanical thinning, and planting sequoias in projected future suitable habitat, which may occur outside current grove distributions. We suggest that managers compare different types of vulnerability assessments and combine vulnerability maps with other sources of information to inform decisions.

Efficacy of adaptation measures to future water scarcity on a global scale

NASA Astrophysics Data System (ADS)

Yoshikawa, S.; Kanae, S.

2015-12-01

Water supply sources for all sector are critically important for agricultural and industrial productivity. The current rapid increase in water use is considered unsustainable and threatens human life. In our previous study (Yoshikawa et al., 2014 in HESS), we estimated the time-varying dependence of water requirements from water supply sources during past and future periods using the global water resources model, H08. The sources of water requirements were specified using four categories: rivers, large reservoirs, medium-size reservoirs, and non-local non-renewable blue water (NNBW). We also estimated ΔNNBW which is defined as an increase in NNBW from the past to the future. From the results, we could require the further development of water supply sources in order to sustain future water use. For coping with water scarcity using ΔNNBW, there is need for adaptation measure. To address adaptation measures, we need to set adaptation options which can be divided between 'Supply enhancement' and 'Demand management'. The supply enhancement includes increased storage, groundwater development, inter-basin transfer, desalination and re-use urban waste water. Demand management is defined as a set of actions controlling water demand by reducing water loss, increasing water productivity, and water re-allocation. In this study, we focus on estimating further future water demand under taking into account of several adaptation measures using H08 model.

Climate risks on potato yield in Europe

NASA Astrophysics Data System (ADS)

Sun, Xun; Lall, Upmanu

2016-04-01

The yield of potatoes is affected by water and temperature during the growing season. We study the impact of a suite of climate variables on potato yield at country level. More than ten climate variables related to the growth of potato are considered, including the seasonal rainfall and temperature, but also extreme conditions at different averaging periods from daily to monthly. A Bayesian hierarchical model is developed to jointly consider the risk of heat stress, cold stress, wet and drought. Future climate risks are investigated through the projection of future climate data. This study contributes to assess the risks of present and future climate risks on potatoes yield, especially the risks of extreme events, which could be used to guide better sourcing strategy and ensure food security in the future.

Simulation of groundwater flow in the shallow aquifer system of the Delmarva Peninsula, Maryland and Delaware

USGS Publications Warehouse

Sanford, Ward E.; Pope, Jason P.; Selnick, David L.; Stumvoll, Ryan F.

2012-01-01

Estimating future loadings of nitrogen to the Chesapeake Bay requires knowledge about the groundwater flow system and the traveltime of water and chemicals between recharge at the water table and the discharge to streams and directly to the bay. The Delmarva Peninsula has a relatively large proportion of its land devoted to agriculture and a large associated nitrogen load in groundwater that has the potential to enter the bay in discharging groundwater. To better understand the shallow aquifer system with respect to this loading and the traveltime to the bay, the U.S. Geological Survey constructed a steady-state groundwater flow model for the region. The model is based on estimates of recharge calculated using recently developed regression equations for evapotranspiration and surface runoff. The hydrogeologic framework incorporated into the model includes unconfined surficial aquifer sediments, as well as subcropping confined aquifers and confining beds down to 300 feet below land surface. The model was calibrated using 48 water-level measurements and 24 tracer-based ages from wells located across the peninsula. The resulting steady-state flow solution was used to estimate ages of water in the shallow aquifer system through the peninsula and the distribution and magnitude of groundwater traveltime from recharge at the water table to discharge in surface-water bodies (referred to as return time). Return times vary but are typically less than 10 years near local streams and greater than 100 years near the stream divides. The model can be used to calculate nitrate transport parameters in various local watersheds and predict future trends in nitrate loadings to Chesapeake Bay for different future nitrogen application scenarios.

Optimizing Land and Water Use at the Local Level to Enhance Global Food Security through Virtual Resources Trade in the World

NASA Astrophysics Data System (ADS)

Cai, X.; Zhang, X.; Zhu, T.

2014-12-01

Global food security is constrained by local and regional land and water availability, as well as other agricultural input limitations and inappropriate national and global regulations. In a theoretical context, this study assumes that optimal water and land uses in local food production to maximize food security and social welfare at the global level can be driven by global trade. It follows the context of "virtual resources trade", i.e., utilizing international trade of agricultural commodities to reduce dependency on local resources, and achieves land and water savings in the world. An optimization model based on the partial equilibrium of agriculture is developed for the analysis, including local commodity production and land and water resources constraints, demand by country, and global food market. Through the model, the marginal values (MVs) of social welfare for water and land at the level of so-called food production units (i.e., sub-basins with similar agricultural production conditions) are derived and mapped in the world. In this personation, we will introduce the model structure, explain the meaning of MVs at the local level and their distribution around the world, and discuss the policy implications for global communities to enhance global food security. In particular, we will examine the economic values of water and land under different world targets of food security (e.g., number of malnourished population or children in a future year). In addition, we will also discuss the opportunities on data to improve such global modeling exercises.

Background estimation of cosmic-ray induced neutrons in Chooz site water veto tank for possible future Ricochet Deployment

NASA Astrophysics Data System (ADS)

Silva, James

2017-09-01

The Ricochet experiment seeks to measure Coherent (neutral-current) Elastic Neutrino-Nucleus Scattering (CE νNS) using metallic superconducting and germanium semi-conducting detectors with sub-keV thresholds placed near a neutrino source such as the Chooz Nuclear Reactor Complex. In this poster, we present an estimate of the flux of cosmic-ray induced neutrons, which represent an important background in any (CE νNS) search, based on reconstructed cosmic ray data from the Chooz Site. We have simulated a possible Ricochet deployment at the Chooz site in GEANT4 focusing on the spallation neutrons generated when cosmic rays interact with the water tank veto that would surround our detector. We further simulate and discuss the effectiveness of various shielding configurations for optimizing the background levels for a future Ricochet deployment.

The crysophere as a resource and hazard - Integrated framework for the assessment of future water resource vulnerability and glacial hazard risk assessment in the Kullu district, Himachal Pradesh, India.

NASA Astrophysics Data System (ADS)

Allen, Simon; Awasthi, Kirtiman; Ballesteros, Juan Antonio; Frey, Holger; Huggel, Christian; Kahn, Mustafa; Linsbauer, Andreas; Rohrer, Mario; Ruiz-Villanueva, Virginia; Salzmann, Nadine; Schauwecker, Simone; Stoffel, Markus

2014-05-01

High mountain environments are particularly susceptible to changes in atmospheric temperature and precipitation patterns, owing to the sensitivity of cryospheric components to melting conditions, and the importance of rainfall and river runoff for sustaining crops and livelihoods. The Himalayan state of Himachal Pradesh (population ca. 6 mil.) is the initial focus of a joint program between the governments of India and Switzerland aiming to build scientific capacity to understand the threat, and plan for adaptation to climate change in the Himalaya. Here we focus on the cryosphere, and provide an overview of the integrated framework we will follow to assess future water resource vulnerability from changes in runoff, and assess future disaster risk from mass movement and flood hazards. At this early stage of our project, we aim to identify key methodological steps, data requirements, and related challenges. The initial implementation of our framework will be centered on the Kullu district. Core and integrative components of both the traditional climate vulnerability framework (eg., IPCC AR4), and the vulnerability and risk concepts of the disaster risk management community (eg., IPCC SREX 2012) include the assessment of sensitivity, exposure, and adaptive capacity. Sensitivity to water vulnerability in the Kullu district requires the quantification of current and future water resource usage at the block or community level, using metrics such as total irrigated land area, total electricity usage, population density and birth rates. Within the disaster risk framework, sensitivity to mass movement and flood hazards will be determined based on factors such as population density and demographics (notably age and gender), strength of building materials etc. Projected temperature and precipitation data from regional climate model output will be used to model changes in melt water runoff and streamflow, determining the exposure of communities and natural systems to future changes in water quantity and quality. For disaster risk assessment, the goal is to identify the intersection of potential mass movement and flood hazards, with exposed people, resources, and assets. Base level information is required on glacier area and volume, mass balance, glacial lake distribution, surface topography, information on snow cover, duration, and snow water equivalent, and gauge measurements on river and stream flows. Where instrumental data is lacking, information of past hydrological regimes and evidence of mass movement can be derived from documentary records (archival reports), from geological indicators (i.e. palaeofloods: sedimentary and biological records over centennial to millennial scales), and from botanical sources (i.e. dendrogeomorphology). The adaptive capacity to face the challenges associated with a changing cryosphere in the Kullu district will require economic, political, and knowledge capacity to plan, prepare, and respond to issues of water quantity and quality, and disaster risk associated with mass movement and flood hazard. Socio-economic information to be assessed includes economic metrics, literacy rates, and population demographic factors such as gender, age, and religion. These same factors largely determine a communities capacity to anticipate, respond to, and recover from disasters.

Too much of a good thing? Nitrate from nitrogen fertilizers and cancer.

PubMed

Ward, Mary H

2009-01-01

Nitrate levels in water supplies have been increasing in many areas of the world; therefore, additional studies of populations with well-characterized exposures are urgently needed to further our understanding of cancer risk associated with nitrate ingestion. Future studies should assess exposure for individuals (e.g., case-control, cohort studies) in a time frame relevant to disease development, and evaluate factors affecting nitrosation. Estimating N-nitroso compounds formation via nitrate ingestion requires information on dietary and drinking water sources of nitrate, inhibitors of nitrosation (e.g., vitamin C), nitrosation precursors (e.g., red meat, nitrosatable drugs), and medical conditions that may increase nitrosation (e.g., inflammatory bowel disease). Studies should account for the potentially different effects of dietary and water sources of nitrate and should include the population using private wells for whom exposure levels are often higher than public supplies.

Using Groundwater Modeling to Evaluate Impacts of Sea Level Rise on A Coastal Riverine Ecosystem: A Case Study of Saint Jones River Water Shed

NASA Astrophysics Data System (ADS)

He, C.; McKenna, T. E.

2016-12-01

A 3-D, transient, variable-density groundwater flow model (SEAWAT) is used to simulate the groundwater response to predicted sea level rise in the Saint Jones River watershed adjacent to the Delaware Estuary. Sea level rise directly leads to substantial changes in the depth of water table, and these changes can extend far inland due to the long tidal rivers in this area. This research studied the impacts of three different sea level rise scenarios (0.5m, 1.0m and 1.5m) on two concerned aspects in the area: failure of septic tank system and loss of agriculture land. The model results indicate that 1) 10% 13% of current existing septic tank will fail as the water table rise to less than 1.5meters from land surface, and 2) approximate 271 to 927 acres of agriculture land, which covers about 4% 13% of total current agriculture land in the study area, will be lost due to water table rise above the effective rooting depth. To count in the uncertainty of climate change in the future, Monte Carlo simulation was applied and a linear transformation model was created and verified to facilitate the tremendous computation.

Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110.

PubMed

Steward, David R; Bruss, Paul J; Yang, Xiaoying; Staggenborg, Scott A; Welch, Stephen M; Apley, Michael D

2013-09-10

Groundwater provides a reliable tap to sustain agricultural production, yet persistent aquifer depletion threatens future sustainability. The High Plains Aquifer supplies 30% of the nation's irrigated groundwater, and the Kansas portion supports the congressional district with the highest market value for agriculture in the nation. We project groundwater declines to assess when the study area might run out of water, and comprehensively forecast the impacts of reduced pumping on corn and cattle production. So far, 30% of the groundwater has been pumped and another 39% will be depleted over the next 50 y given existing trends. Recharge supplies 15% of current pumping and would take an average of 500-1,300 y to completely refill a depleted aquifer. Significant declines in the region's pumping rates will occur over the next 15-20 y given current trends, yet irrigated agricultural production might increase through 2040 because of projected increases in water use efficiencies in corn production. Water use reductions of 20% today would cut agricultural production to the levels of 15-20 y ago, the time of peak agricultural production would extend to the 2070s, and production beyond 2070 would significantly exceed that projected without reduced pumping. Scenarios evaluate incremental reductions of current pumping by 20-80%, the latter rate approaching natural recharge. Findings substantiate that saving more water today would result in increased net production due to projected future increases in crop water use efficiencies. Society has an opportunity now to make changes with tremendous implications for future sustainability and livability.

Tapping unsustainable groundwater stores for agricultural production in the High Plains Aquifer of Kansas, projections to 2110

PubMed Central

Steward, David R.; Bruss, Paul J.; Yang, Xiaoying; Staggenborg, Scott A.; Welch, Stephen M.; Apley, Michael D.

2013-01-01

Groundwater provides a reliable tap to sustain agricultural production, yet persistent aquifer depletion threatens future sustainability. The High Plains Aquifer supplies 30% of the nation’s irrigated groundwater, and the Kansas portion supports the congressional district with the highest market value for agriculture in the nation. We project groundwater declines to assess when the study area might run out of water, and comprehensively forecast the impacts of reduced pumping on corn and cattle production. So far, 30% of the groundwater has been pumped and another 39% will be depleted over the next 50 y given existing trends. Recharge supplies 15% of current pumping and would take an average of 500–1,300 y to completely refill a depleted aquifer. Significant declines in the region’s pumping rates will occur over the next 15–20 y given current trends, yet irrigated agricultural production might increase through 2040 because of projected increases in water use efficiencies in corn production. Water use reductions of 20% today would cut agricultural production to the levels of 15–20 y ago, the time of peak agricultural production would extend to the 2070s, and production beyond 2070 would significantly exceed that projected without reduced pumping. Scenarios evaluate incremental reductions of current pumping by 20–80%, the latter rate approaching natural recharge. Findings substantiate that saving more water today would result in increased net production due to projected future increases in crop water use efficiencies. Society has an opportunity now to make changes with tremendous implications for future sustainability and livability. PMID:23980153

Climate change, water rights, and water supply: The case of irrigated agriculture in Idaho

NASA Astrophysics Data System (ADS)

Xu, Wenchao; Lowe, Scott E.; Adams, Richard M.

2014-12-01

We conduct a hedonic analysis to estimate the response of agricultural land use to water supply information under the Prior Appropriation Doctrine by using Idaho as a case study. Our analysis includes long-term climate (weather) trends and water supply conditions as well as seasonal water supply forecasts. A farm-level panel data set, which accounts for the priority effects of water rights and controls for diversified crop mixes and rotation practices, is used. Our results indicate that farmers respond to the long-term surface and ground water conditions as well as to the seasonal water supply variations. Climate change-induced variations in climate and water supply conditions could lead to substantial damages to irrigated agriculture. We project substantial losses (up to 32%) of the average crop revenue for major agricultural areas under future climate scenarios in Idaho. Finally, farmers demonstrate significantly varied responses given their water rights priorities, which imply that the distributional impact of climate change is sensitive to institutions such as the Prior Appropriation Doctrine.

Water Data Report: An Annotated Bibliography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunham Whitehead, Camilla; Melody, Moya

2007-05-01

This report and its accompanying Microsoft Excel workbooksummarize water data we found to support efforts of the EnvironmentalProtection Agency s WaterSense program. WaterSense aims to extend theoperating life of water and wastewater treatment facilities and prolongthe availability of water resourcesby reducing residential andcommercial water consumption through the voluntary replacement ofinefficient water-using products with more efficient ones. WaterSense hasan immediate need for water consumption data categorized by sector and,for the residential sector, per capita data available by region. Thisinformation will assist policy makers, water and wastewater utilityplanners, and others in defining and refining program possibilities.Future data needs concern water supply, wastewatermore » flow volumes, waterquality, and watersheds. This report focuses primarily on the immediateneed for data regarding water consumption and product end-use. We found avariety of data on water consumption at the national, state, andmunicipal levels. We also found several databases related towater-consuming products. Most of the data are available in electronicform on the Web pages of the data-collecting organizations. In addition,we found national, state, and local data on water supply, wastewater,water quality, and watersheds.« less

Acute Gastroenteritis and Recreational Water: Highest Burden ...

EPA Pesticide Factsheets

OBJECT I VES : To provide summary estimates of gastroenteritis risks and illness burden associated with recreational water exposure and determine whether children have higher risks and burden.METHODS: We combined individual participant data from 13 prospective cohorts at marine and freshwater beaches throughout the United States (n = 84 411). We measured incident outcomes within 10 days of exposure: diarrhea, gastrointestinal illness, missed daily activity (work, school, vacation), and medical visits. We estimated the relationship between outcomes and 2 exposures: body immersion swimming and Enterococcus spp. fecal indicator bacteria levels in the water. We also estimated the population-attributable risk associated with these exposures.RESULTS: Water exposure accounted for 21% of diarrhea episodes and 9% of missed daily activities but was unassociated with gastroenteritis leading to medical consultation. Children aged 0 to 4 and 5 to 10 years had the most water exposure, exhibited stronger associations between levels of water quality and illness, and accounted for the largest attributable illness burden.CONCLUSIONS: The higher gastroenteritis risk and associated burden in young children presents important new information to inform future recreational water quality guidelines designed to protect public health. Meta-analysis of 13 beach sites and nearly 90,000 subjects found that swimming at the beach increased diarrhea incidence and individuals who swam in water

Real time monitoring of water level and temperature in storage fuel pools through optical fibre sensors.

PubMed

Rizzolo, S; Périsse, J; Boukenter, A; Ouerdane, Y; Marin, E; Macé, J-R; Cannas, M; Girard, S

2017-08-18

We present an innovative architecture of a Rayleigh-based optical fibre sensor for the monitoring of water level and temperature inside storage nuclear fuel pools. This sensor, able to withstand the harsh constraints encountered under accidental conditions such as those pointed-out during the Fukushima-Daiichi event (temperature up to 100 °C and radiation dose level up to ~20 kGy), exploits the Optical Frequency Domain Reflectometry technique to remotely monitor a radiation resistant silica-based optical fibre i.e. its sensing probe. We validate the efficiency and the robustness of water level measurements, which are extrapolated from the temperature profile along the fibre length, in a dedicated test bench allowing the simulation of the environmental operating and accidental conditions. The conceived prototype ensures an easy, practical and no invasive integration into existing nuclear facilities. The obtained results represent a significant breakthrough and comfort the ability of the developed system to overcome both operating and accidental constraints providing the distributed profiles of the water level (0-to-5 m) and temperature (20-to-100 °C) with a resolution that in accidental condition is better than 3 cm and of ~0.5 °C respectively. These new sensors will be able, as safeguards, to contribute and reinforce the safety in existing and future nuclear power plants.

A Novel Application of Agent-based Modeling: Projecting Water Access and Availability Using a Coupled Hydrologic Agent-based Model in the Nzoia Basin, Kenya

NASA Astrophysics Data System (ADS)

Le, A.; Pricope, N. G.

2015-12-01

Projections indicate that increasing population density, food production, and urbanization in conjunction with changing climate conditions will place stress on water resource availability. As a result, a holistic understanding of current and future water resource distribution is necessary for creating strategies to identify the most sustainable means of accessing this resource. Currently, most water resource management strategies rely on the application of global climate predictions to physically based hydrologic models to understand potential changes in water availability. However, the need to focus on understanding community-level social behaviors that determine individual water usage is becoming increasingly evident, as predictions derived only from hydrologic models cannot accurately represent the coevolution of basin hydrology and human water and land usage. Models that are better equipped to represent the complexity and heterogeneity of human systems and satellite-derived products in place of or in conjunction with historic data significantly improve preexisting hydrologic model accuracy and application outcomes. We used a novel agent-based sociotechnical model that combines the Soil and Water Assessment Tool (SWAT) and Agent Analyst and applied it in the Nzoia Basin, an area in western Kenya that is becoming rapidly urbanized and industrialized. Informed by a combination of satellite-derived products and over 150 household surveys, the combined sociotechnical model provided unique insight into how populations self-organize and make decisions based on water availability. In addition, the model depicted how population organization and current management alter water availability currently and in the future.

Quantifying the potential for reservoirs to secure future surface water yields in the world’s largest river basins

NASA Astrophysics Data System (ADS)

Liu, Lu; Parkinson, Simon; Gidden, Matthew; Byers, Edward; Satoh, Yusuke; Riahi, Keywan; Forman, Barton

2018-04-01

Surface water reservoirs provide us with reliable water supply, hydropower generation, flood control and recreation services. Yet reservoirs also cause flow fragmentation in rivers and lead to flooding of upstream areas, thereby displacing existing land-use activities and ecosystems. Anticipated population growth and development coupled with climate change in many regions of the globe suggests a critical need to assess the potential for future reservoir capacity to help balance rising water demands with long-term water availability. Here, we assess the potential of large-scale reservoirs to provide reliable surface water yields while also considering environmental flows within 235 of the world’s largest river basins. Maps of existing cropland and habitat conservation zones are integrated with spatially-explicit population and urbanization projections from the Shared Socioeconomic Pathways to identify regions unsuitable for increasing water supply by exploiting new reservoir storage. Results show that even when maximizing the global reservoir storage to its potential limit (∼4.3–4.8 times the current capacity), firm yields would only increase by about 50% over current levels. However, there exist large disparities across different basins. The majority of river basins in North America are found to gain relatively little firm yield by increasing storage capacity, whereas basins in Southeast Asia display greater potential for expansion as well as proportional gains in firm yield under multiple uncertainties. Parts of Europe, the United States and South America show relatively low reliability of maintaining current firm yields under future climate change, whereas most of Asia and higher latitude regions display comparatively high reliability. Findings from this study highlight the importance of incorporating different factors, including human development, land-use activities, and climate change, over a time span of multiple decades and across a range of different scenarios when quantifying available surface water yields and the potential for reservoir expansion.

Modeling Storm-Induced Inundation on the Yukon-Kuskokwim Delta for Present and Future Climates

NASA Astrophysics Data System (ADS)

Ravens, T. M.; Allen, J.

2012-12-01

The Yukon-Kuskokwim (YK) Delta is a large delta on the west coast of Alaska and one of the few remaining deltas that is largely free of anthropogenic impacts. The delta hosts a wide-range of nesting birds including the endangered Spectacled Eider. The delta plain, with an elevation of about 2 m (m.s.l.) - and an average tidal range of 2.7 m - is subject to frequent inundation by storm surges originating from the adjacent Bering Sea. Here, we report on our efforts to validate a storm-surge modeling system consisting of a course-grid ADCIRC model covering the Bering and Chukchi Seas and a Delft3D fine-grid model of the southern YK Delta. The storm surge models are validated based on measured water levels from 2007-2010 and using satellite observations of inundation due to large storms in 2005 and 2006. About 10 storms over the past 30 years are modeled. Based on model output, we computed a spatially distributed inundation index which is a time-integral of water level throughout the fine-grid model domain from individual storms and from the 30 year period. In order to examine the change in inundation in future climates, the models of the 30 year period were re-run assuming a 1 and 2 meter sea level rise. The impact of climate change on inundation frequency and intensity - using the inundation index - is reported. Future work will relate the present and projected inundation index to ecological parameters such as bird-nest concentration and vegetation type.

On inclusion of water resource management in Earth system models - Part 1: Problem definition and representation of water demand

NASA Astrophysics Data System (ADS)

Nazemi, A.; Wheater, H. S.

2015-01-01

Human activities have caused various changes to the Earth system, and hence the interconnections between human activities and the Earth system should be recognized and reflected in models that simulate Earth system processes. One key anthropogenic activity is water resource management, which determines the dynamics of human-water interactions in time and space and controls human livelihoods and economy, including energy and food production. There are immediate needs to include water resource management in Earth system models. First, the extent of human water requirements is increasing rapidly at the global scale and it is crucial to analyze the possible imbalance between water demands and supply under various scenarios of climate change and across various temporal and spatial scales. Second, recent observations show that human-water interactions, manifested through water resource management, can substantially alter the terrestrial water cycle, affect land-atmospheric feedbacks and may further interact with climate and contribute to sea-level change. Due to the importance of water resource management in determining the future of the global water and climate cycles, the World Climate Research Program's Global Energy and Water Exchanges project (WRCP-GEWEX) has recently identified gaps in describing human-water interactions as one of the grand challenges in Earth system modeling (GEWEX, 2012). Here, we divide water resource management into two interdependent elements, related firstly to water demand and secondly to water supply and allocation. In this paper, we survey the current literature on how various components of water demand have been included in large-scale models, in particular land surface and global hydrological models. Issues of water supply and allocation are addressed in a companion paper. The available algorithms to represent the dominant demands are classified based on the demand type, mode of simulation and underlying modeling assumptions. We discuss the pros and cons of available algorithms, address various sources of uncertainty and highlight limitations in current applications. We conclude that current capability of large-scale models to represent human water demands is rather limited, particularly with respect to future projections and coupled land-atmospheric simulations. To fill these gaps, the available models, algorithms and data for representing various water demands should be systematically tested, intercompared and improved. In particular, human water demands should be considered in conjunction with water supply and allocation, particularly in the face of water scarcity and unknown future climate.

Flood Prediction for the Tam Nong District in Mekong Delta Using Hydrological Modelling and Hydrologic Remote Sensing Technique

NASA Astrophysics Data System (ADS)

Kappas, Martin; Nguyen Hong, Quang; Thanh, Nga Pham Thi; Thu, Hang Le Thi; Nguyen Vu, Giang; Degener, Jan; Rafiei Emam, Ammar

2017-04-01

There has been an increasing attention to the large trans-boundary Mekong river basin due to various problems related to water management and flood control, for instance. Vietnam Mekong delta is located at the downstream of the river basin where is affected most by this human-induced reduction in flows from the upstream. On the other hand, the flood plain of nine anastomosing channels is increasingly effected by the seawater intrusion due to sea level rising of climate change. This results in negative impacts of salinization, drought, and floods, while formerly flooding had frequently brought positive natural gain of irrigation water and alluvial aggradation. In this research, our aim is to predict flooding for the better water management adaptation and control. We applied the model HEC-SSP 2.1 to analyze flood flow frequency, two-dimensional unsteady flow calculations in HEC-RAS 5.0 for simulating a floodplain inundation. Remote sensing-based water level (Jason-2) and inundation map were used for validation and comparison with the model simulations. The results revealed a reduction of water level at all the monitoring stations, particularly in the last decade. In addition, a trend of the inundation extension gradually declined, but in some periods it remained severe due to water release from upstream reservoirs during the rainy season (October-November). We found an acceptable agreement between the HEC-RAS and remote sensing flooding maps (around 70%). Based on the flood routine analysis, we could conclude that the water level will continue lower and lead to a trend of drought and salinization harsher in the near future. Keywords: Mekong delta, flood control, inundation, water management, hydrological modelling, remote sensing

Arsenic contamination of drinking water in Ireland: A spatial analysis of occurrence and potential risk.

PubMed

McGrory, Ellen R; Brown, Colin; Bargary, Norma; Williams, Natalya Hunter; Mannix, Anthony; Zhang, Chaosheng; Henry, Tiernan; Daly, Eve; Nicholas, Sarah; Petrunic, Barbara M; Lee, Monica; Morrison, Liam

2017-02-01

The presence of arsenic in groundwater has become a global concern due to the health risks from drinking water with elevated concentrations. The Water Framework Directive (WFD) of the European Union calls for drinking water risk assessment for member states. The present study amalgamates readily available national and sub-national scale datasets on arsenic in groundwater in the Republic of Ireland. However, due to the presence of high levels of left censoring (i.e. arsenic values below an analytical detection limit) and changes in detection limits over time, the application of conventional statistical methods would inhibit the generation of meaningful results. In order to handle these issues several arsenic databases were integrated and the data modelled using statistical methods appropriate for non-detect data. In addition, geostatistical methods were used to assess principal risk components of elevated arsenic related to lithology, aquifer type and groundwater vulnerability. Geographic statistical methods were used to overcome some of the geographical limitations of the Irish Environmental Protection Agency (EPA) sample database. Nearest-neighbour inverse distance weighting (IDW) and local indicator of spatial association (LISA) methods were used to estimate risk in non-sampled areas. Significant differences were also noted between different aquifer lithologies, indicating that Rhyolite, Sandstone and Shale (Greywackes), and Impure Limestone potentially presented a greater risk of elevated arsenic in groundwaters. Significant differences also occurred among aquifer types with poorly productive aquifers, locally important fractured bedrock aquifers and regionally important fissured bedrock aquifers presenting the highest potential risk of elevated arsenic. No significant differences were detected among different groundwater vulnerability groups as defined by the Geological Survey of Ireland. This research will assist management and future policy directions of groundwater resources at EU level and guide future research focused on understanding arsenic mobilisation processes to facilitate in guiding future development, testing and treatment requirements of groundwater resources. Copyright © 2016 Elsevier B.V. All rights reserved.

Hydrogeology and numerical simulation of the unconsolidated glacial aquifer in the Pootatuck River Basin, Newtown, Connecticut

USGS Publications Warehouse

Carlson, Carl S.; Mondazzi, Remo A.; Bjerklie, David M.; Brown, Craig J.

2010-01-01

A study of the groundwater and stream-aquifer interaction in the Pootatuck River Basin, Newtown, Connecticut, was conducted to analyze the effect of production wells on the groundwater levels and streamflow in the Pootatuck River as part of a cooperative program between the U.S. Geological Survey and Newtown, Connecticut. This study will help address concerns about the increasing competition for water for human uses and protection of aquatic habitat. The groundwater-flow model developed in the study was designed for use as a tool to assist planners in assessing the effects of potential future development, which will change the amount and distribution of recharge available to the groundwater system. Several different techniques were used to investigate the interconnection between the stream and the aquifer. Temperature, groundwater levels, stream stage, and stable-isotope data collected during aquifer tests at the principal production wells in the Pootatuck River Basin, as well as groundwater-flow simulations of the system, indicate that more than half of the water pumped from the wells comes from the Pootatuck River. This finding potentially has a large effect on approaches for protecting the water quality of the pumped water. Increases in the amount of impervious surface from future development will reduce and redistribute recharge to the groundwater system. The simulation of future development scenarios showed a decrease in the simulated base flow in the main stem of the Pootatuck River and in all of the 26 simulated subbasins, with some of the subbasins showing a decrease of more than 20 percent when new development had 85 percent impervious area. The groundwater-flow model and particle tracking were used to determine areas that contribute recharge to the five production wells available for use in the Pootatuck River Basin. These areas included narrow portions of the aquifer that extended beyond the immediate upgradient areas, probably because of deeper groundwater-flow paths.

Future Nuisance Flooding at Boston Caused by Astronomical Tides Alone

NASA Technical Reports Server (NTRS)

Ray, Richard D.; Foster, Grant

2016-01-01

Sea level rise necessarily triggers more occurrences of minor, or nuisance, flooding events along coastlines, a fact well documented in recent studies. At some locations nuisance flooding can be brought about merely by high spring tides, independent of storms, winds, or other atmospheric conditions. Analysis of observed water levels at Boston indicates that tidal flooding began to occur there in 2011 and will become more frequent in subsequent years. A compilation of all predicted nuisance-flooding events, induced by astronomical tides alone, is presented through year 2050. The accuracy of the tide prediction is improved when several unusual properties of Gulf of Maine tides, including secular changes, are properly accounted for. Future mean sea-level rise at Boston cannot be predicted with comparable confidence, so two very different climate scenarios are adopted; both predict a large increase in the frequency and the magnitude of tidal flooding events.

Water-centric nexus for response to climate change on agriculture and forest sector: The case of the Korean Peninsula

NASA Astrophysics Data System (ADS)

Lim, C. H.; Choi, Y.; Jeon, S. W.; Lee, W. K.

2017-12-01

Given their complexity and the number of stakeholders involved, it is difficult to solve social issues or problems based on an analysis that focuses on a single dimension. In particular, research surrounding climate change is inherently multidisciplinary and there is a need for highly pluralistic nexuses that can be used as a framework for policy decisions. Here, we suggest to water-centric nexus on agriculture and forest sector to improve response to climate change. The nexus is composed agricultural water demand and forest water supply to enhancing water-related adaptation to climate change in the Korean Peninsula. Agricultural productivity and water use related variables was estimating by EPIC crop model, and InVEST model applied for estimation of forest water supply. Results under two climate change scenarios (RCP4.5 and 8.5) and time period (2050s and 2070s), the forest water supply for the all future climate scenarios will increase significantly. In case of agriculture, irrigated crops experienced only the benefits of climate change, but rainfed crops were negatively impacted. It was also found that crop irrigation demand in the future is expected to be around twice as high as baseline levels, thus making irrigation more difficult to successfully implement. These hydrological threats have the potential to greatly reduce food security. In the nexus perspectives, the drop in the productivity of rainfed crops and the increase in irrigation demand in the agriculture sector can be resolved through interconnections with the forest sector. Appropriate management of the water supply in future climatic conditions characterized by increasing precipitation can maintain and expand agricultural areas through irrigation. To achieve this, a time-series water supply versus demand analysis must be performed so that an accurate balance between supply and demand can be established. Water-centric interactions of the agriculture and forest are the basis of nexus-based adaptation and they can suggest effective climate change responses for the Korean peninsula. In particular, this approach will be effective in transforming sectors that experience trade-offs into ones that promote synergies.

Sensitivity of water resources in the Delaware River basin to climate variability and change

USGS Publications Warehouse

Ayers, Mark A.; Wolock, David M.; McCabe, Gregory J.; Hay, Lauren E.; Tasker, Gary D.

1994-01-01

Because of the greenhouse effect, projected increases in atmospheric carbon dioxide levels might cause global warming, which in turn could result in changes in precipitation patterns and evapotranspiration and in increases in sea level. This report describes the greenhouse effect; discusses the problems and uncertainties associated with the detection, prediction, and effects of climate change; and presents the results of sensitivity analyses of how climate change might affect water resources in the Delaware River basin. Sensitivity analyses suggest that potentially serious shortfalls of certain water resources in the basin could result if some scenarios for climate change come true . The results of model simulations of the basin streamflow demonstrate the difficulty in distinguishing the effects that climate change versus natural climate variability have on streamflow and water supply . The future direction of basin changes in most water resources, furthermore, cannot be precisely determined because of uncertainty in current projections of regional temperature and precipitation . This large uncertainty indicates that, for resource planning, information defining the sensitivities of water resources to a range of climate change is most relevant . The sensitivity analyses could be useful in developing contingency plans for evaluating and responding to changes, should they occur.

Segmentation of Environmental Time Lapse Image Sequences for the Determination of Shore Lines Captured by Hand-Held Smartphone Cameras

NASA Astrophysics Data System (ADS)

Kröhnert, M.; Meichsner, R.

2017-09-01

The relevance of globally environmental issues gains importance since the last years with still rising trends. Especially disastrous floods may cause in serious damage within very short times. Although conventional gauging stations provide reliable information about prevailing water levels, they are highly cost-intensive and thus just sparsely installed. Smartphones with inbuilt cameras, powerful processing units and low-cost positioning systems seem to be very suitable wide-spread measurement devices that could be used for geo-crowdsourcing purposes. Thus, we aim for the development of a versatile mobile water level measurement system to establish a densified hydrological network of water levels with high spatial and temporal resolution. This paper addresses a key issue of the entire system: the detection of running water shore lines in smartphone images. Flowing water never appears equally in close-range images even if the extrinsics remain unchanged. Its non-rigid behavior impedes the use of good practices for image segmentation as a prerequisite for water line detection. Consequently, we use a hand-held time lapse image sequence instead of a single image that provides the time component to determine a spatio-temporal texture image. Using a region growing concept, the texture is analyzed for immutable shore and dynamic water areas. Finally, the prevalent shore line is examined by the resultant shapes. For method validation, various study areas are observed from several distances covering urban and rural flowing waters with different characteristics. Future work provides a transformation of the water line into object space by image-to-geometry intersection.

Measuring domestic water use: a systematic review of methodologies that measure unmetered water use in low-income settings.

PubMed

Tamason, Charlotte C; Bessias, Sophia; Villada, Adriana; Tulsiani, Suhella M; Ensink, Jeroen H J; Gurley, Emily S; Mackie Jensen, Peter Kjaer

2016-11-01

To present a systematic review of methods for measuring domestic water use in settings where water meters cannot be used. We systematically searched EMBASE, PubMed, Water Intelligence Online, Water Engineering and Development Center, IEEExplore, Scielo, and Science Direct databases for articles that reported methodologies for measuring water use at the household level where water metering infrastructure was absent or incomplete. A narrative review explored similarities and differences between the included studies and provide recommendations for future research in water use. A total of 21 studies were included in the review. Methods ranged from single-day to 14-consecutive-day visits, and water use recall ranged from 12 h to 7 days. Data were collected using questionnaires, observations or both. Many studies only collected information on water that was carried into the household, and some failed to mention whether water was used outside the home. Water use in the selected studies was found to range from two to 113 l per capita per day. No standardised methods for measuring unmetered water use were found, which brings into question the validity and comparability of studies that have measured unmetered water use. In future studies, it will be essential to define all components that make up water use and determine how they will be measured. A pre-study that involves observations and direct measurements during water collection periods (these will have to be determined through questioning) should be used to determine optimal methods for obtaining water use information in a survey. Day-to-day and seasonal variation should be included. A study that investigates water use recall is warranted to further develop standardised methods to measure water use; in the meantime, water use recall should be limited to 24 h or fewer. © 2016 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

Simulating groundwater-induced sewer flooding

NASA Astrophysics Data System (ADS)

Mijic, A.; Mansour, M.; Stanic, M.; Jackson, C. R.

2016-12-01

During the last decade, Chalk catchments of southern England experienced severe groundwater flooding. High groundwater levels resulted in the groundwater ingress into the sewer network that led to restricted toilet use and the overflow of diluted, but untreated sewage to road surfaces, rivers and water courses. In response to these events the water and sewerage company Thames Water Utilities Ltd (TWUL) had to allocate significant funds to mitigate the impacts. It was estimated that approximately £19m was spent responding to the extreme wet weather of 2013-14, along with the use of a fleet of over 100 tankers. However, the magnitude of the event was so large that these efforts could not stop the discharge of sewage to the environment. This work presents the analysis of the risk of groundwater-induced sewer flooding within the Chalk catchment of the River Lambourn, Berkshire. A spatially distributed groundwater model was used to assess historic groundwater flood risk and the potential impacts of changes in future climate. We then linked this model to an urban groundwater model to enable us to simulate groundwater-sewer interaction in detail. The modelling setup was used to identify relationships between infiltration into sewers and groundwater levels at specific points on TWUL's sewer network, and to estimate historic and future groundwater flood risk, and how this varies across the catchment. The study showed the significance of understanding the impact of groundwater on the urban water systems, and producing information that can inform a water company's response to groundwater flood risk, their decision making process and their asset management planning. However, the knowledge gained through integrated modelling of groundwater-sewer interactions has highlighted limitations of existing approaches for the simulation of these coupled systems. We conclude this work with number of recommendations about how to improve such hydrological/sewer analysis.

The value of long-term monitoring in the development of ground-water-flow models

USGS Publications Warehouse

Feinstein, Daniel T.; Hart, David J.; Krohelski, James T.

2004-01-01

As environmental issues have come to the forefront of public concern, so has the awareness of the importance of ground water in the overall water cycle and as a source of the Nation’s drinking water. Heightened interest has spawned a host of scientific enterprises (Taylor and Alley, 2001). Some activities are directed toward collection of water-level data and related information to monitor the physical and chemical state of the resource. Other activities are directed at interpretive studies undertaken, for example, to optimize the location of new water-supply wells or to protect rivers and lakes fed by ground water. An important type of interpretive study is the computer ground-water-flow model that inte- grates field data in a mathematical framework. Long-term, systematic collection of hydro- logic data is crucial to the construction and testing of ground-water models so that they can reproduce the evolution of flow systems and forecast future conditions. 

Operationalising uncertainty in data and models for integrated water resources management.

PubMed

Blind, M W; Refsgaard, J C

2007-01-01

Key sources of uncertainty of importance for water resources management are (1) uncertainty in data; (2) uncertainty related to hydrological models (parameter values, model technique, model structure); and (3) uncertainty related to the context and the framing of the decision-making process. The European funded project 'Harmonised techniques and representative river basin data for assessment and use of uncertainty information in integrated water management (HarmoniRiB)' has resulted in a range of tools and methods to assess such uncertainties, focusing on items (1) and (2). The project also engaged in a number of discussions surrounding uncertainty and risk assessment in support of decision-making in water management. Based on the project's results and experiences, and on the subsequent discussions a number of conclusions can be drawn on the future needs for successful adoption of uncertainty analysis in decision support. These conclusions range from additional scientific research on specific uncertainties, dedicated guidelines for operational use to capacity building at all levels. The purpose of this paper is to elaborate on these conclusions and anchoring them in the broad objective of making uncertainty and risk assessment an essential and natural part in future decision-making processes.

[Arsenic levels in drinking water supplies from underground sources in the community of Madrid].

PubMed

Aragonés Sanz, N; Palacios Diez, M; Avello de Miguel, A; Gómez Rodríguez, P; Martínez Cortés, M; Rodríguez Bernabeu, M J

2001-01-01

In 1998, arsenic concentrations of more than 50 micrograms/l were detected in some drinking water supplies from underground sources in the Autonomous Community of Madrid, which is the maximum permissible concentration for drinking water in Spain. These two facts have meant the getting under way of a specific plan for monitoring arsenic in the drinking water in the Autonomous Community of Madrid. The results of the first two sampling processes conducted in the arsenic level monitoring plan set out are presented. In the initial phase, water samples from 353 water supplies comprised within the census of the Public Health Administration of the Autonomous Community of Madrid were analyzed. A water supply risk classification was made based on these initial results. In a second phase, six months later, the analyses were repeated on those 35 water supplies which were considered to possibly pose a risk to public health. Seventy-four percent (74%) of the water supplies studied in the initial phase were revealed to have an arsenic concentration of less than 10 micrograms/l, 22.6% containing levels of 10 micrograms/l-50 micrograms/l, and 3.7% over 50 micrograms/l. Most of the water supplies showing arsenic levels of more than 10 micrograms/l are located in the same geographical area. In the second sampling process (six months later), the 35 water supplies classified as posing a risk were included. Twenty-six (26) of these supplies were revealed to have the same arsenic level ((10-50 micrograms/l), and nine changed category, six of which had less than 10 micrograms/l and three more than 50 micrograms/l. In the Autonomous Community of Madrid, less than 2% of the population drinks water coming from supplies which are from underground sources. The regular water quality monitoring conducted by the Public Health Administration has led to detecting the presence of more than 50 micrograms/l of arsenic in sixteen drinking water supplies from underground sources, which is the maximum permissible level under the laws currently in force in Spain. Measures have been taken to prevent water from being used from these water supplies. Around 20% of the water supplies studies must take measures in the near future to lower the arsenic concentration to below 10 micrograms/l when the water directive which is currently in the process of being written into Spanish law enters into effect.

Water market transfers in South Africa: Two case studies

NASA Astrophysics Data System (ADS)

Nieuwoudt, W. L.; Armitage, R. M.

2004-09-01

Statistical analyses (discriminant, logit, and principal components) of water transfers in the Lower Orange River showed that water rights were transferred to farmers with the highest return per unit of water applied, those producing table grapes, and with high-potential arable "outer land" without water rights. Only unused water (sleeper right) was transferred, while water saved (through adoption of conservation practices) was retained possibly for security purposes. A second study in the Nkwaleni Valley in northern KwaZulu-Natal found that no water market had emerged despite the scarcity of water in the area. No willing sellers of water rights existed. Demand for institutional change to establish tradable water rights may take more time in the second area since crop profitability in this area is similar for potential buyers and nonbuyers. Transaction costs appear larger than benefits from market transactions. Farmers generally use all their water rights in the second area and retain surplus water rights as security against drought because of unreliable river flow. This study indicates that these irrigation farmers are highly risk averse (downside risk). Government policies that increase the level of risk and reduce security of licenses are estimated to have a significant effect on future investment in irrigation. In an investment model the following variables explain future investment: expected profits, liquidity, risk aversion (Arrow-Pratt), and security of water use rights. The study is seen in the light of the New South African Water Act of 1998. According to this act, the ownership of water in South Africa has changed from private to public. This reform may not impede the development of water markets in South Africa since in the well-developed water markets of the United States, western states claim ownership of water within their boundaries. All states in the western United States allow private rights in the use of water to be established and sold.

Defining Established and Emerging Microbial Risks in the Aquatic Environment: Current Knowledge, Implications, and Outlooks

PubMed Central

Rowan, Neil J.

2011-01-01

This timely review primarily addresses important but presently undefined microbial risks to public health and to the natural environment. It specifically focuses on current knowledge, future outlooks and offers some potential alleviation strategies that may reduce or eliminate the risk of problematic microbes in their viable but nonculturable (VBNC) state and Cryptosporidium oocysts in the aquatic environment. As emphasis is placed on water quality, particularly surrounding efficacy of decontamination at the wastewater treatment plant level, this review also touches upon other related emerging issues, namely, the fate and potential ecotoxicological impact of untreated antibiotics and other pharmaceutically active compounds in water. Deciphering best published data has elucidated gaps between science and policy that will help stakeholders work towards the European Union's Water Framework Directive (2000/60/EC), which provides an ambitious legislative framework for water quality improvements within its region and seeks to restore all water bodies to “good ecological status” by 2015. Future effective risk-based assessment and management, post definition of the plethora of dynamic inter-related factors governing the occurrence, persistence and/or control of these presently undefined hazards in water will also demand exploiting and harnessing tangential advances in allied disciplines such as mathematical and computer modeling that will permit efficient data generation and transparent reporting to be undertaken by well-balanced consortia of stakeholders. PMID:20976256

Understanding Coastal Wetland Vulnerability to Sea-Level Rise Enhanced Inundation Using Real-Time Stage Monitoring, LiDAR, and Monte Carlo Simulation in Everglades National Park

NASA Astrophysics Data System (ADS)

Cooper, H.; Zhang, C.

2017-12-01

Coastal wetlands are one of the most productive ecological systems in the world, providing critical habitat area and valuable ecosystem services such as carbon sequestration. However, due to their location in low lying areas, coastal wetlands are particularly vulnerable to sea-level rise (SLR). Everglades National Park (ENP) encompasses the southern-most portion of the Greater Everglades Ecosystem, and is the largest subtropical wetland in the USA. Water depths have shown to have a significant relationship to vegetation community composition and organization while also playing a crucial role in vegetation health throughout the Everglades. Live plants play a vital role in maintaining soil structure (i.e. elevation), and decreases in vegetation health can cause peat collapse or wetland loss resulting in dramatic habitat, organic soil, and elevation loss posing concerns for Everglades management and restoration. One suspected mechanism for peat collapse is enhanced inundation due to SLR, thus mapping and modeling water depths is a critical component to understanding the potential impacts of future SLR. Previous research in the Everglades focused on a conventional Water Depth Model (WDM) approach where a Digital Elevation Model (DEM) is subtracted from a Water Table Elevation Model (WTEM). In this study, the conventional WDM approach is extended to a more rigorous WDM technique so that the accuracy and precision of the underlying data may be considered. Monte Carlo simulation is used to propagate probability distributions through our SLR depth model using our Random Forest-based LiDAR DEM, Empirical Bayesian Kriging-based WTEMs, uncertainties in vertical datums, soil accretion projections, and regional sea-level rise projections. Water depth maps were produced for the wet and dry seasons in April and October, which successfully revealed the potential spatial and temporal water depth variations due to future SLR. It is concluded that a more rigorous WDM technique helps to increase the integrity of derived products used to support and guide coastal restoration managers and planners under the challenge of rising seas.

Southern Ocean Bottom Water Characteristics in CMIP5 Models

NASA Astrophysics Data System (ADS)

Heuzé, Céline; Heywood, Karen; Stevens, David; Ridley, Jeff

2013-04-01

The depiction of Southern Ocean deep water properties and formation processes in climate models is an indicator of their capability to simulate future climate, heat and carbon uptake, and sea level rise. Southern Ocean potential temperature and density averaged over 1986-2005 from fifteen CMIP5 climate models are compared with an observed climatology, focusing on bottom water properties. The mean bottom properties are reasonably accurate for half of the models, but the other half may not yet have approached an equilibrium state. Eleven models create dense water on the Antarctic shelf, but it does not spill off and propagate northwards, alternatively mixing rapidly with less dense water. Instead most models create deep water by open ocean deep convection. Models with large deep convection areas are those with a strong seasonal cycle in sea ice. The most accurate bottom properties occur in models hosting deep convection in the Weddell and Ross gyres.

Network global navigation satellite system surveys to harmonize American and Canadian datum for the Lake Champlain Basin

USGS Publications Warehouse

Flynn, Robert H.; Rydlund, Jr., Paul H.; Martin, Daniel J.

2016-03-08

Lake-gage water-surface elevations determined during the 3 days of surveys were converted to water-surface elevations referenced to the North American Vertical Datum of 1988 by using calculated offsets and historical water-surface elevations. In this report, an “offset” refers to the adjustment that needs to be applied to published data from a particular gage to produce elevation data referenced to the North American Vertical Datum of 1988. Offsets presented in this report can be used in the evaluation of water-surface elevations in a common datum for Lake Champlain and the Richelieu River. In addition, the water-level data referenced to the common datum (as determined from the offsets) may be used to calibrate flow models and support future modeling studies developed for Lake Champlain and the Richelieu River.

Ground-Water Availability in the Wailuku Area, Maui, Hawai'i

USGS Publications Warehouse

Gingerich, Stephen B.

2008-01-01

Most of the public water supply in Maui, Hawai'i, is from a freshwater lens in the Wailuku area of the island. Because of population growth, ground-water withdrawals from wells in this area increased from less than 10 Mgal/d during 1970 to about 23 Mgal/d during 2006. In response to increased withdrawals from the freshwater lens in the Wailuku area, water levels declined, the transition zone between freshwater and saltwater became shallower, and the chloride concentrations of water pumped from wells increased. These responses led to concern over the long-term sustainability of withdrawals from existing and proposed wells. A three-dimensional numerical ground-water flow and transport model was developed to simulate the effects of selected withdrawal and recharge scenarios on water levels, on the transition zone between freshwater and saltwater, and on surface-water/ground-water interactions. The model was constructed using time-varying recharge, withdrawals, and ocean levels. Hydraulic characteristics used to construct the model were initially based on published estimates but ultimately were varied to obtain better agreement between simulated and measured water levels and salinity profiles in the modeled area during the period 1926-2006. Scenarios included ground-water withdrawal at 2006 and 1996 rates and locations with average recharge (based on 2000-04 land use and 1926-2004 rainfall) and withdrawal at redistributed rates and locations with several different recharge scenarios. Simulation results indicate that continuing 1996 and 2006 withdrawal distributions into the future results in decreased water levels, a thinner freshwater lens, increased salinity from pumped wells, and higher salinity at several current withdrawal sites. A redistributed withdrawal condition in which ground-water withdrawal was redistributed to maximize withdrawal and minimize salinities in the withdrawn water was determined. The redistributed withdrawal simulates 27.1 Mgal/d of withdrawal from 14 wells or well fields in the Wailuku area. Simulation results from the five scenarios that include redistributed withdrawal conditions indicate the following for the Wailuku Aquifer Sector: (1) withdrawal during times of average recharge rates cause average water levels to decrease 2-3 ft and the transition zone to become more than 200 ft shallower after 150 years; (2) a 5-yr drought condition similar to the 1998-2002 drought results in additional salinity increases after 30 years (12.5 years of normal recharge after drought conditions) but only one well has salinity increases of concern; (3) additional recharge from restored streamflow significantly increases water levels, thickens the freshwater body, and decreases salinity at withdrawal sites in the Waihe'e and 'Iao Aquifer Systems; and (4) a complete removal of irrigation recharge decreases water levels and increases salinity in the central isthmus where irrigation is reduced, but recharge through restored streams still significantly increases water levels, thickens the freshwater body, and decreases salinity at withdrawal sites in the Waihe'e and 'Iao Aquifer Systems.

Water Quality and Hydrology of Silver Lake, Barron County, Wisconsin, With Special Emphasis on Responses of a Terminal Lake to Changes in Phosphorus Loading and Water Level

USGS Publications Warehouse

Robertson, Dale M.; Rose, William J.; Fitzpatrick, Faith A.

2009-01-01

Silver Lake is typically an oligotrophic-to-mesotrophic, soft-water, terminal lake in northwestern Wisconsin. A terminal lake is a closed-basin lake with surface-water inflows but no surface-water outflows to other water bodies. After several years with above-normal precipitation, very high water levels caused flooding of several buildings near the lake and erosion of soil around much of the shoreline, which has been associated with a degradation in water quality (increased phosphorus and chlorophyll a concentrations and decreased water clarity). To gain a better understanding of what caused the very high water levels and degradation in water quality and collect information to better understand the lake and protect it from future degradation, the U.S. Geological Survey did a detailed study from 2004 to 2008. This report describes results of the study; specifically, lake-water quality, historical changes in water level, water and phosphorus budgets for the two years monitored in the study, results of model simulations that demonstrate how changes in phosphorus inputs affect lake-water quality, and the relative importance of changes in hydrology and changes in the watershed to the water quality of the lake. From 1987 to about 1996, water quality in Silver Lake was relatively stable. Since 1996, however, summer average total phosphorus concentrations increased from about 0.008 milligrams per liter (mg/L) to 0.018 mg/L in 2003, before decreasing to 0.011 mg/L in 2008. From 1996 to 2003, Secchi depths decreased from about 14 to 7.4 feet, before increasing to about 19 feet in 2008. Therefore, Silver Lake is typically classified as oligotrophic to mesotrophic; however, during 2002-4, the lake was classified as mesotrophic to eutrophic. Because productivity in Silver Lake is limited by phosphorus, phosphorus budgets for the lake were constructed for monitoring years 2005 and 2006. The average annual input of phosphorus was 216 pounds: 78 percent from tributary and nearshore runoff and 22 percent from atmospheric deposition. Because Silver Lake is hydraulically mounded above the local groundwater system, little or no input of phosphorus to the lake is from groundwater and septic systems. Silver Lake had previously been incorrectly described as a groundwater flowthrough lake. Phosphorus budgets were constructed for a series of dry years (low water levels) and a series of wet years (high water levels). About 6 times more phosphorus was input to the lake during wet years with high water levels than during the dry years. Phosphorus from erosion represented 13-20 percent of the phosphorus input during years with very high water levels. Results from the Canfield and Bachman eutrophication model and Carlson trophic state index equations demonstrated that water quality in Silver Lake directly responds to changes in external phosphorus input, with the percent change in chlorophyll a being about 80 percent of the percent change in total phosphorus input and the change in Secchi depth and total phosphorus concentrations being about 40 and 50 percent of the percent change in input, respectively. Therefore, changes in phosphorus input should impact water quality. Specific scenarios were simulated with the models to describe the effects of natural (climate-driven) and anthropogenic (human-induced) changes. Results of these scenarios demonstrated that several years of above-normal precipitation cause sustained high water levels and a degradation in water quality, part of which is due to erosion of the shoreline. Results also demonstrated that 1) changes in tributary and nearshore runoff have a dramatic effect on lake-water quality, 2) diverting water into the lake to increase the water level is expected to degrade the water quality, and 3) removal of water to decrease the water level of the lake is expected to have little effect on water quality. Fluctuations in water levels since 1967, when records began for the lake, are representative