Sample records for water availability limits

  1. Water availability limits tolerance of apical damage in the Chilean tarweed Madia sativa

    NASA Astrophysics Data System (ADS)

    Gonzáles, Wilfredo L.; Suárez, Lorena H.; Molina-Montenegro, Marco A.; Gianoli, Ernesto

    2008-07-01

    Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness. Numerous studies have shown that plant tolerance is affected by nutrient availability, but the effect of soil moisture has received less attention. We evaluated tolerance of apical damage (clipping that mimicked insect damage) under two watering regimes (control watering and drought) in the tarweed Madia sativa (Asteraceae). We recorded number of heads with seeds and total number of heads as traits related to fitness. Net photosynthetic rate, water use efficiency, number of branches, shoot biomass, and the root:shoot biomass ratio were measured as traits potentially related to tolerance via compensatory responses to damage. In the drought treatment, damaged plants showed ≈43% reduction in reproductive fitness components in comparison with undamaged plants. In contrast, there was no significant difference in reproductive fitness between undamaged and damaged plants in the control watering treatment. Shoot biomass was not affected by apical damage. The number of branches increased after damage in both water treatments but this increase was limited by drought stress. Net photosynthetic rate increased in damaged plants only in the control watering treatment. Water use efficiency increased with drought stress and, in plants regularly watered, also increased after damage. Root:shoot ratio was higher in the low water treatment and damaged plants tended to reduce root:shoot ratio only in this water treatment. It is concluded that water availability limits tolerance to apical damage in M. sativa, and that putative compensatory mechanisms are differentially affected by water availability.

  2. A review of limits on microbial activity in the cryosphere: temperature and water availability

    NASA Astrophysics Data System (ADS)

    Bakermans, C.

    2017-12-01

    The extent of microbial activity in the cryosphere likely depends on many things: the presence of liquid water, an adequate energy and nutrient supply (amount and flux), the absence of damaging conditions, exposure to low temperatures, and the time to evolve adaptations to low temperature conditions. Determining the extent of microbial activity in the cryosphere is a challenge complicated by the reduced availability of liquid water as water freezes and the low rates of diffusion and reaction brought on by low temperatures. Despite these limitations, many studies have demonstrated that reproduction by microorganisms is possible at temperatures of -10 to -20°C and that metabolism continues to even lower temperatures of about -30°C. In addition, microcosm studies in frozen soils and permafrost have demonstrated respiration down to temperatures of -18°C and DNA synthesis at temperatures from 0 to -20°C. In the environment, low temperature conditions (and lack of liquid water) appear to limit microbial activity in a few places like Don Juan Pond and University Valley in Antarctica. Microorganisms may be metabolically active in Arctic permafrost, but metabolism may be so exceptionally slow as to escape detection. Given the slow metabolism expected and the short geological age of permafrost (3 million years at the longest), there is probably insufficient time for microorganisms to evolve to become better adapted to live at subfreezing temperatures. Indeed, terrestrial life may never have the chance to evolve to exploit the low temperature capabilities of its biomolecules in view of the limited times at which cold environments persist on Earth. These observational studies of microorganisms in low temperature environments of the Polar regions expose how the extent of microbial activity at low temperature is entangled with other factors (perhaps inextricably); how the lack of liquid water at low temperatures appears to be the true limit on activity at low temperatures

  3. Water Availability--The Connection Between Water Use and Quality

    USGS Publications Warehouse

    Hirsch, Robert M.; Hamilton, Pixie A.; Miller, Timothy L.; Myers, Donna N.

    2008-01-01

    Water availability has become a high priority in the United States, in large part because competition for water is becoming more intense across the Nation. Population growth in many areas competes with demands for water to support irrigation and power production. Cities, farms, and power plants compete for water needed by aquatic ecosystems to support their minimum flow requirements. At the same time, naturally occurring and human-related contaminants from chemical use, land use, and wastewater and industrial discharge are introduced into our waters and diminish its quality. The fact that degraded quality limits the availability and suitability of water for critical uses is a well-known reality in many communities. What may be less understood, but equally true, is that our everyday use of water can significantly affect water quality, and thus its availability. Landscape features (such as geology, soils, and vegetation) along with water-use practices (such as ground-water withdrawals and irrigation) govern water availability because, together, they affect the movement of chemical compounds over the land and in the subsurface. Understanding the interactions of human activities with natural sources and the landscape is critical to effectively managing water and sustaining water availability in the future.

  4. Ecohydrology of agroecosystems: probabilistic description of yield reduction risk under limited water availability

    NASA Astrophysics Data System (ADS)

    Vico, Giulia; Porporato, Amilcare

    2013-04-01

    Supplemental irrigation represents one of the main strategies to mitigate the effects of climate variability and stabilize yields. Irrigated agriculture currently provides 40% of food production and its relevance is expected to further increase in the near future, in face of the projected alterations of rainfall patterns and increase in food, fiber, and biofuel demand. Because of the significant investments and water requirements involved in irrigation, strategic choices are needed to preserve productivity and profitability, while maintaining a sustainable water management - a nontrivial task given the unpredictability of the rainfall forcing. To facilitate decision making under uncertainty, a widely applicable probabilistic framework is proposed. The occurrence of rainfall events and irrigation applications are linked probabilistically to crop development during the growing season and yields at harvest. Based on these linkages, the probability density function of yields and corresponding probability density function of required irrigation volumes, as well as the probability density function of yields under the most common case of limited water availability are obtained analytically, as a function of irrigation strategy, climate, soil and crop parameters. The full probabilistic description of the frequency of occurrence of yields and water requirements is a crucial tool for decision making under uncertainty, e.g., via expected utility analysis. Furthermore, the knowledge of the probability density function of yield allows us to quantify the yield reduction hydrologic risk. Two risk indices are defined and quantified: the long-term risk index, suitable for long-term irrigation strategy assessment and investment planning, and the real-time risk index, providing a rigorous probabilistic quantification of the emergence of drought conditions during a single growing season in an agricultural setting. Our approach employs relatively few parameters and is thus easily and

  5. Summary of available state ambient stream-water-quality data, 1990-98, and limitations for national assessment

    USGS Publications Warehouse

    Pope, Larry M.; Rosner, Stacy M.; Hoffman, Darren C.; Ziegler, Andrew C.

    2004-01-01

    of these factors, a high level of uncertainty exists in a national assessment of water quality. The purpose of this report is to present a summary of electronically available State ambient stream-water-quality data for 10 selected constituents and measurements from monitoring sites with nine or more analyses for 199098 and to discuss limitations for use of the data for national assessment. These analyses were statistiscally summarized by monitoring site and State, and the results presented in tabular format. Most of the selected constituents or measurements have U.S. Environmental Protection Agency criteria or guidelines for aquatic-life or drinking-water purposes. A significant finding of this investigation is that for a large percentage of monitoring sites in the Nation, there are insufficient data to meet U.S. Environmental Protection Agency recommendations for determining if water-quality conditions are degraded and for making informed decisions regarding total maximum daily loads.

  6. 78 FR 27233 - Clean Water Act: Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-09

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9811-4] Clean Water Act: Availability of List Decisions... announces the availability of EPA's action identifying water quality limited segments and associated pollutants in Louisiana to be listed pursuant to Clean Water Act Section 303(d), and request for public...

  7. Water and nonpoint source pollution estimation in the watershed with limited data availability based on hydrological simulation and regression model.

    PubMed

    Huiliang, Wang; Zening, Wu; Caihong, Hu; Xinzhong, Du

    2015-09-01

    Nonpoint source (NPS) pollution is considered as the main reason for water quality deterioration; thus, to quantify the NPS loads reliably is the key to implement watershed management practices. In this study, water quality and NPS loads from a watershed with limited data availability were studied in a mountainous area in China. Instantaneous water discharge was measured through the velocity-area method, and samples were taken for water quality analysis in both flood and nonflood days in 2010. The streamflow simulated by Hydrological Simulation Program-Fortran (HSPF) from 1995 to 2013 and a regression model were used to estimate total annual loads of various water quality parameters. The concentrations of total phosphorus (TP) and total nitrogen (TN) were much higher during the flood seasons, but the concentrations of ammonia nitrogen (NH3-N) and nitrate nitrogen (NO3-N) were lower during the flood seasons. Nevertheless, only TP concentration was positively correlated with the flow rate. The fluctuation of annual load from this watershed was significant. Statistical results indicated the significant contribution of pollutant fluxes during flood seasons to annual fluxes. The loads of TP, TN, NH3-N, and NO3-N in the flood seasons were accounted for 58-85, 60-82, 63-88, 64-81% of the total annual loads, respectively. This study presented a new method for estimation of the water and NPS loads in the watershed with limited data availability, which simplified data collection to watershed model and overcame the scale problem of field experiment method.

  8. Suspended sediments limit coral sperm availability.

    PubMed

    Ricardo, Gerard F; Jones, Ross J; Clode, Peta L; Humanes, Adriana; Negri, Andrew P

    2015-12-14

    Suspended sediment from dredging activities and natural resuspension events represent a risk to the reproductive processes of coral, and therefore the ongoing maintenance of reefal populations. To investigate the underlying mechanisms that could reduce the fertilisation success in turbid water, we conducted several experiments exposing gametes of the corals Acropora tenuis and A. millepora to two sediment types. Sperm limitation was identified in the presence of siliciclastic sediment (230 and ~700 mg L(-1)), with 2-37 fold more sperm required to achieve maximum fertilisation rates, when compared with sediment-free treatments. This effect was more pronounced at sub-optimum sperm concentrations. Considerable (>45%) decreases in sperm concentration at the water's surface was recorded in the presence of siliciclastic sediment and a >20% decrease for carbonate sediment. Electron microscopy then confirmed sediment entangled sperm and we propose entrapment and sinking is the primary mechanism reducing sperm available to the egg. Longer exposure to suspended sediments and gamete aging further decreased fertilisation success when compared with a shorter exposure. Collectively, these findings demonstrate that high concentrations of suspended sediments effectively remove sperm from the water's surface during coral spawning events, reducing the window for fertilisation with potential subsequent flow-on effects for recruitment.

  9. The effect of limited availability of N or water on C allocation to fine roots and annual fine root turnover in Alnus incana and Salix viminalis.

    PubMed

    Rytter, Rose-Marie

    2013-09-01

    The effect of limited nitrogen (N) or water availability on fine root growth and turnover was examined in two deciduous species, Alnus incana L. and Salix viminalis L., grown under three different regimes: (i) supply of N and water in amounts which would not hamper growth, (ii) limited N supply and (iii) limited water supply. Plants were grown outdoors during three seasons in covered and buried lysimeters placed in a stand structure and filled with quartz sand. Computer-controlled irrigation and fertilization were supplied through drip tubes. Production and turnover of fine roots were estimated by combining minirhizotron observations and core sampling, or by sequential core sampling. Annual turnover rates of fine roots <1 mm (5-6 year(-1)) and 1-2 mm (0.9-2.8 year(-1)) were not affected by changes in N or water availability. Fine root production (<1 mm) differed between Alnus and Salix, and between treatments in Salix; i.e., absolute length and biomass production increased in the order: water limited < unlimited < N limited. Few treatment effects were detected for fine roots 1-2 mm. Proportionally more C was allocated to fine roots (≤2 mm) in N or water-limited Salix; 2.7 and 2.3 times the allocation to fine roots in the unlimited regime, respectively. Estimated input to soil organic carbon increased by ca. 20% at N limitation in Salix. However, future studies on fine root decomposition under various environmental conditions are required. Fine root growth responses to N or water limitation were less pronounced in Alnus, thus indicating species differences caused by N-fixing capacity and slower initial growth in Alnus, or higher fine root plasticity in Salix. A similar seasonal growth pattern across species and treatments suggested the influence of outer stimuli, such as temperature and light.

  10. 77 FR 15368 - Clean Water Act; Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9646-9] Clean Water Act; Availability of List Decisions...) proposed decision identifying water quality limited segments and associated pollutants in Oregon to be listed pursuant to section 303(d)(2) of the Clean Water Act (CWA). EPA is proposing to add 1004 water...

  11. 77 FR 54909 - Clean Water Act: Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-06

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9724-6] Clean Water Act: Availability of List Decisions... notice announces EPA's decision to identify certain water quality limited waters and the associated pollutant to be listed pursuant to the Clean Water Act Section 303(d)(2) on New York's list of impaired...

  12. Water Availability in a Warming World

    NASA Astrophysics Data System (ADS)

    Aminzade, Jennifer

    As climate warms during the 21st century, the resultant changes in water availability are a vital issue for society, perhaps even more important than the magnitude of warming itself. Yet our climate models disagree in their forecasts of water availability, limiting our ability to plan accordingly. This thesis investigates future water availability projections from Coupled Ocean-Atmosphere General Circulation Models (GCMs), primarily using two water availability measures: soil moisture and the Supply Demand Drought Index (SDDI). Chapter One introduces methods of measuring water availability and explores some of the fundamental differences between soil moisture, SDDI and the Palmer Drought Severity Index (PDSI). SDDI and PDSI tend to predict more severe future drought conditions than soil moisture; 21st century projections of SDDI show conditions rivaling North American historic mega-droughts. We compare multiple potential evapotranspiration (EP) methods in New York using input from the GISS Model ER GCM and local station data from Rochester, NY, and find that they compare favorably with local pan evaporation measurements. We calculate SDDI and PDSI values using various EP methods, and show that changes in future projections are largest when using EP methods most sensitive to global warming, not necessarily methods producing EP values with the largest magnitudes. Chapter Two explores the characteristics and biases of the five GCMs and their 20th and 21st century climate projections. We compare atmospheric variables that drive water availability changes globally, zonally, and geographically among models. All models show increases in both dry and wet extremes for SDDI and soil moisture, but increases are largest for extreme drying conditions using SDDI. The percentage of gridboxes that agree on the sign of change of soil moisture and SDDI between models is very low, but does increase in the 21st century. Still, differences between models are smaller than differences

  13. Impacts of fresh and aged biochars on plant available water and water use efficiency

    USDA-ARS?s Scientific Manuscript database

    The ability of soils to hold sufficient plant available water (PAW) between rainfall events is critical to crop productivity. Most studies indicate that biochar amendments decrease soil bulk density and increase soil water retention. However, limited knowledge exists regarding biochars ability to in...

  14. Water Resources Availability in Kabul, Afghanistan

    NASA Astrophysics Data System (ADS)

    Akbari, A. M.; Chornack, M. P.; Coplen, T. B.; Emerson, D. G.; Litke, D. W.; Mack, T. J.; Plummer, N.; Verdin, J. P.; Verstraeten, I. M.

    2008-12-01

    construction practices and little planning. By 2050, the available water resources in the Kabul Basin may be reduced as a result of Central Asian climate changes. Increasing air temperatures associated with climate change are likely to lead to a decreasing snowpack and an earlier growing season, resulting in less recharge from river leakage. As a result, more than 60 percent of existing supply wells may become dry or inoperative. The impacts of climate change would likely be greatest in the agricultural regions in the western areas of the basin. Water resources in the in northern areas of the basin may meet future water needs. However, in other areas of the basin, particularly the more urbanized southern areas adjacent to and including the city of Kabul, water resources may be stressed. Ground water in deep aquifers, more than 100 m below land surface, is presently unused. Conceptual ground-water-flow simulations indicate that ground water in deep aquifers may be thousands of years old. The deep aquifer may sustain limited increases in municipal water use, but may not support increased agricultural use which is much greater than municipal use. However, the hydraulic feasibility and quality of deep ground-water extractions are not well known and are being investigated.

  15. Availability of Water in the Kabul Basin, Afghanistan

    USGS Publications Warehouse

    Mack, Thomas J.; Chornack, Michael P.; Coplen, T.B.; Plummer, Niel; Rezai, M.T.; Verstraeten, Ingrid M.

    2010-01-01

    The availability of water resources is vital to the social and economic well being and rebuilding of Afghanistan. Kabul City currently (2010) has a population of nearly 4 million and is growing rapidly as a result of periods of relative security and the return of refugees. Population growth and recent droughts have placed new stresses on the city's limited water resources and have caused many wells to become contaminated, dry, or inoperable in recent years. The projected vulnerability of Central and West Asia to climate change (Cruz and others, 2007; Milly and others, 2005) and observations of diminishing glaciers in Afghanistan (Molnia, 2009) have heightened concerns for future water availability in the Kabul Basin of Afghanistan.

  16. Has water limited our imagination for aridland biogeochemistry?

    PubMed

    Austin, Amy T

    2011-05-01

    The classic ecological paradigm for deserts, that all processes are controlled by water availability, has limited our imagination for exploring other controls on the cycling of carbon and nutrients in aridland ecosystems. This review of recent studies identifies alternative mechanisms that challenge the idea that all soil processes in aridlands are proximately water-limited, and highlights the significance of photodegradation of aboveground litter and the overriding importance of spatial heterogeneity as a modulator of biotic responses to water availability. Aridlands currently occupy >30% of the terrestrial land surface and are expanding. It is therefore critical to incorporate these previously unappreciated mechanisms in our understanding of aridland biogeochemistry to mitigate the effects of desertification and global change. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Summary of resources available to small water systems for meeting the 10 ppb arsenic drinking water limit.

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

    Krumhansl, James Lee; Thomson, Bruce M.; Ziegler, Matt

    2007-01-01

    With the lowering of the EPA maximum contaminant level of arsenic from 50 parts per billion (ppb) to 10 ppb, many public water systems in the country and in New Mexico in particular, are faced with making decisions about how to bring their system into compliance. This document provides detail on the options available to the water systems and the steps they need to take to achieve compliance with this regulation. Additionally, this document provides extensive resources and reference information for additional outreach support, financing options, vendors for treatment systems, and media pilot project results.

  18. 75 FR 68783 - Clean Water Act Section 303(d): Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-09

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9223-5] Clean Water Act Section 303(d): Availability of List Decisions AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of availability. SUMMARY: This action announces the availability of EPA decisions identifying water quality limited segments and...

  19. Topographic, edaphic, and vegetative controls on plant-available water

    USGS Publications Warehouse

    Dymond, Salli F.; Bradford, John B.; Bolstad, Paul V.; Kolka, Randall K.; Sebestyen, Stephen D.; DeSutter, Thomas S.

    2017-01-01

    Soil moisture varies within landscapes in response to vegetative, physiographic, and climatic drivers, which makes quantifying soil moisture over time and space difficult. Nevertheless, understanding soil moisture dynamics for different ecosystems is critical, as the amount of water in a soil determines a myriad ecosystem services and processes such as net primary productivity, runoff, microbial decomposition, and soil fertility. We investigated the patterns and variability in in situ soil moisture measurements converted to plant-available water across time and space under different vegetative cover types and topographic positions at the Marcell Experimental Forest (Minnesota, USA). From 0 – 228.6 cm soil depth, plant-available water was significantly higher under the hardwoods (12%), followed by the aspen (8%) and red pine (5%) cover types. Across the same soil depth, toeslopes were wetter (mean plant-available water = 10%) than ridges and backslopes (mean plant-available water was 8%), although these differences were not statistically significant (p < 0.05). Using a mixed model of fixed and random effects, we found that cover type, soil texture, and time were related to plant-available water and that topography was not significantly related to plant-available water within this low-relief landscape. Additionally, during the three-year monitoring period, red pine and quaking aspen sites experienced plant-available water levels that may be considered limiting to plant growth and function. Given that increasing temperatures and more erratic precipitation patterns associated with climate change may result in decreased soil moisture in this region, these species may be sensitive and vulnerable to future shifts in climate.

  20. 76 FR 20664 - Clean Water Act Section 303(d): Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-13

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9294-5] Clean Water Act Section 303(d): Availability of List... notice announces the availability of EPA's action identifying water quality limited segments and associated pollutants in Louisiana to be listed pursuant to Clean Water Act Section 303(d), and request for...

  1. 75 FR 52735 - Clean Water Act Section 303(d): Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-27

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9189-7] Clean Water Act Section 303(d): Availability of List...: This notice announces the availability of EPA's decision identifying 12 water quality limited waterbodies and associated pollutants in South Dakota to be listed pursuant to the Clean Water Act Section 303...

  2. Peak water limits to freshwater withdrawal and use

    PubMed Central

    Gleick, Peter H.; Palaniappan, Meena

    2010-01-01

    Freshwater resources are fundamental for maintaining human health, agricultural production, economic activity as well as critical ecosystem functions. As populations and economies grow, new constraints on water resources are appearing, raising questions about limits to water availability. Such resource questions are not new. The specter of “peak oil”—a peaking and then decline in oil production—has long been predicted and debated. We present here a detailed assessment and definition of three concepts of “peak water”: peak renewable water, peak nonrenewable water, and peak ecological water. These concepts can help hydrologists, water managers, policy makers, and the public understand and manage different water systems more effectively and sustainably. Peak renewable water applies where flow constraints limit total water availability over time. Peak nonrenewable water is observable in groundwater systems where production rates substantially exceed natural recharge rates and where overpumping or contamination leads to a peak of production followed by a decline, similar to more traditional peak-oil curves. Peak “ecological” water is defined as the point beyond which the total costs of ecological disruptions and damages exceed the total value provided by human use of that water. Despite uncertainties in quantifying many of these costs and benefits in consistent ways, more and more watersheds appear to have already passed the point of peak water. Applying these concepts can help shift the way freshwater resources are managed toward more productive, equitable, efficient, and sustainable use. PMID:20498082

  3. 40 CFR 412.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 412.13 Section 412.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT). (a... limitations representing the application of BAT: There shall be no discharge of process waste water pollutants...

  4. 40 CFR 412.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 412.13 Section 412.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT). (a... limitations representing the application of BAT: There shall be no discharge of process waste water pollutants...

  5. 40 CFR 412.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 412.13 Section 412.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT). (a... limitations representing the application of BAT: There shall be no discharge of process waste water pollutants...

  6. 40 CFR 412.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 412.13 Section 412.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT). (a... limitations representing the application of BAT: There shall be no discharge of process waste water pollutants...

  7. 40 CFR 412.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 412.13 Section 412.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT). (a... limitations representing the application of BAT: There shall be no discharge of process waste water pollutants...

  8. Lower limits of crop water use in three soil textural classes

    USDA-ARS?s Scientific Manuscript database

    Accurate knowledge of the amount of soil water available for crop use allows better management of limited water supplies. Using neutron scattering, we determined the mean lower limit of field soil water use (LL*F, m**3 m**-3) to a depth of 2.2 m at harvest (three seasons each) of short-season maize...

  9. 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

  10. Effects of soil water availability on water fluxes in winter wheat

    NASA Astrophysics Data System (ADS)

    Cai, G.; Vanderborght, J.; Langensiepen, M.; Vereecken, H.

    2014-12-01

    Quantifying soil water availability in water-limited ecosystems on plant water use continues to be a practical problem in agronomy. Transpiration which represents plant water demand is closely in relation to root water uptake in the root zone and sap flow in plant stems. However, few studies have been concentrated on influences of soil moisture on root water uptake and sap flow in crops. This study was undertaken to investigate (i) whether root water uptake and sap flow correlate with the transpiration estimated by the Penman-Monteith model for winter wheat(Triticum aestivum), and (ii) for which soil water potentials in the root zone, the root water uptake and sap flow rates in crop stems would be reduced. Therefore, we measured sap flow velocities by an improved heat-balance approach (Langensiepen et al., 2014), calculated crop transpiration by Penman-Monteith model, and simulated root water uptake by HYDRUS-1D on an hourly scale for different soil water status in winter wheat. In order to assess the effects of soil water potential on root water uptake and sap flow, an average soil water potential was calculated by weighting the soil water potential at a certain depth with the root length density. The temporal evolution of root length density was measured using horizontal rhizotubes that were installed at different depths.The results showed that root water uptake and sap flow matched well with the computed transpiration by Penman-Monteith model in winter wheat when the soil water potential was not limiting root water uptake. However, low soil water content restrained root water uptake, especially when soil water potential was lower than -90 kPa in the top soil. Sap flow in wheat was not affected by the observed soil water conditions, suggesting that stomatal conductance was not sensitive to soil water potentials. The effect of drought stress on root water uptake and sap flow in winter wheat was only investigated in a short time (after anthesis). Further research

  11. Simulation of water-energy fluxes through small-scale reservoir systems under limited data availability

    NASA Astrophysics Data System (ADS)

    Papoulakos, Konstantinos; Pollakis, Giorgos; Moustakis, Yiannis; Markopoulos, Apostolis; Iliopoulou, Theano; Dimitriadis, Panayiotis; Koutsoyiannis, Demetris; Efstratiadis, Andreas

    2017-04-01

    Small islands are regarded as promising areas for developing hybrid water-energy systems that combine multiple sources of renewable energy with pumped-storage facilities. Essential element of such systems is the water storage component (reservoir), which implements both flow and energy regulations. Apparently, the representation of the overall water-energy management problem requires the simulation of the operation of the reservoir system, which in turn requires a faithful estimation of water inflows and demands of water and energy. Yet, in small-scale reservoir systems, this task in far from straightforward, since both the availability and accuracy of associated information is generally very poor. For, in contrast to large-scale reservoir systems, for which it is quite easy to find systematic and reliable hydrological data, in the case of small systems such data may be minor or even totally missing. The stochastic approach is the unique means to account for input data uncertainties within the combined water-energy management problem. Using as example the Livadi reservoir, which is the pumped storage component of the small Aegean island of Astypalaia, Greece, we provide a simulation framework, comprising: (a) a stochastic model for generating synthetic rainfall and temperature time series; (b) a stochastic rainfall-runoff model, whose parameters cannot be inferred through calibration and, thus, they are represented as correlated random variables; (c) a stochastic model for estimating water supply and irrigation demands, based on simulated temperature and soil moisture, and (d) a daily operation model of the reservoir system, providing stochastic forecasts of water and energy outflows. Acknowledgement: This research is conducted within the frame of the undergraduate course "Stochastic Methods in Water Resources" of the National Technical University of Athens (NTUA). The School of Civil Engineering of NTUA provided moral support for the participation of the students

  12. 75 FR 71431 - Clean Water Act Section 303(d): Availability of List Decisions Correction

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-23

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9230-1] Clean Water Act Section 303(d): Availability of List... Availability. SUMMARY: This action corrects a Federal Register notice that published on November 9, 2010 at 75 FR 68783 announcing the availability of EPA decisions identifying water quality limited segments and...

  13. Bioenergy Sorghum Crop Model Predicts VPD-Limited Transpiration Traits Enhance Biomass Yield in Water-Limited Environments

    PubMed Central

    Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

    2017-01-01

    of genotypes with optimized VPD-limited transpiration traits and deployment of these crops in water limited growing environments. The energy sorghum model and VPD-limited transpiration trait implementation are made available to simulate performance in other target environments. PMID:28377779

  14. Bioenergy Sorghum Crop Model Predicts VPD-Limited Transpiration Traits Enhance Biomass Yield in Water-Limited Environments.

    PubMed

    Truong, Sandra K; McCormick, Ryan F; Mullet, John E

    2017-01-01

    of genotypes with optimized VPD-limited transpiration traits and deployment of these crops in water limited growing environments. The energy sorghum model and VPD-limited transpiration trait implementation are made available to simulate performance in other target environments.

  15. Bioenergy sorghum crop model predicts VPD-limited transpiration traits enhance biomass yield in water-limited environments

    DOE PAGES

    Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

    2017-03-21

    development of genotypes with optimized VPD-limited transpiration traits and deployment of these crops in water limited growing environments. As a result, the energy sorghum model and VPD-limited transpiration trait implementation aremade available to simulate performance in other target environments.« less

  16. Bioenergy sorghum crop model predicts VPD-limited transpiration traits enhance biomass yield in water-limited environments

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

    Truong, Sandra K.; McCormick, Ryan F.; Mullet, John E.

    development of genotypes with optimized VPD-limited transpiration traits and deployment of these crops in water limited growing environments. As a result, the energy sorghum model and VPD-limited transpiration trait implementation aremade available to simulate performance in other target environments.« less

  17. 77 FR 27770 - Clean Water Act Section 303(d): Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9670-5] Clean Water Act Section 303(d): Availability of List...: This notice announces EPA's decision identifying certain water quality limited waterbodies, and the associated pollutant, in Utah to be listed pursuant to the Clean Water Act Section 303(d)(2), and requests...

  18. Differential responses of Picea asperata and Betula albosinensis to nitrogen supply imposed by water availability.

    PubMed

    Yin, Chunying; Palmroth, Sari; Pang, Xueyong; Tang, Bo; Liu, Qing; Oren, Ram

    2018-05-16

    A pot experiment was conducted to investigate the effects of nitrogen (N) addition (0, 20, 40 g N m-2 year-1, N0, N20, N40, respectively) on the growth, and biomass accumulation and allocation of coniferous and deciduous (Picea asperata Mast. and Betula albosinensis Burk.) seedlings under a range of soil moisture limitation (40%, 50%, 60%, 80% and 100% of field capacity, FC). At 100% FC, growth of shade-tolerant P. asperata increased with N supply, while that of shade-intolerant B. albosinensis reached a maximum at N20, declining somewhat thereafter. At 60% FC and lower moisture content, water availability limited the growth of P. asperata seedlings, while N availability became progressively limiting to growth with moisture increasing above 60% FC. The transition from principally water-limited response to N-limited response in B. albosinensis occurred at lower moisture content. For P. asperata, these patterns reflected the responses of roots, consistent with changes in root/shoot biomass. For B. albosinensis the response reflected changes in shoot dimensions and root biomass fraction, the latter decreasing with size and foliar [N]. We are not aware of another study demonstrating such differences in the shape of the growth responses of seedlings of differing potential growth rate, across a range in belowground resource supply. The responses of leaf photosynthesis (as well as photosynthetic water and N-use efficiencies) were consistent with the observed growth response of P. asperata to water and N availability, but not of B. albosinensis, suggesting that leaf area dynamics (not measured) dominated the response of this species. Betula albosinensis, a fast-growing species, has a relative narrow range of soil water and N availability for maximum growth, achieved by preferential allocation to the shoot as resources meet the requirements at moderate N and water supply. In contrast, P. asperata increases shoot biomass progressively with increasing resources up to moderate

  19. Energy saving in WWTP: Daily benchmarking under uncertainty and data availability limitations.

    PubMed

    Torregrossa, D; Schutz, G; Cornelissen, A; Hernández-Sancho, F; Hansen, J

    2016-07-01

    Efficient management of Waste Water Treatment Plants (WWTPs) can produce significant environmental and economic benefits. Energy benchmarking can be used to compare WWTPs, identify targets and use these to improve their performance. Different authors have performed benchmark analysis on monthly or yearly basis but their approaches suffer from a time lag between an event, its detection, interpretation and potential actions. The availability of on-line measurement data on many WWTPs should theoretically enable the decrease of the management response time by daily benchmarking. Unfortunately this approach is often impossible because of limited data availability. This paper proposes a methodology to perform a daily benchmark analysis under database limitations. The methodology has been applied to the Energy Online System (EOS) developed in the framework of the project "INNERS" (INNovative Energy Recovery Strategies in the urban water cycle). EOS calculates a set of Key Performance Indicators (KPIs) for the evaluation of energy and process performances. In EOS, the energy KPIs take in consideration the pollutant load in order to enable the comparison between different plants. For example, EOS does not analyse the energy consumption but the energy consumption on pollutant load. This approach enables the comparison of performances for plants with different loads or for a single plant under different load conditions. The energy consumption is measured by on-line sensors, while the pollutant load is measured in the laboratory approximately every 14 days. Consequently, the unavailability of the water quality parameters is the limiting factor in calculating energy KPIs. In this paper, in order to overcome this limitation, the authors have developed a methodology to estimate the required parameters and manage the uncertainty in the estimation. By coupling the parameter estimation with an interval based benchmark approach, the authors propose an effective, fast and reproducible

  20. Water Availability for Shale Gas Development in Sichuan Basin, China.

    PubMed

    Yu, Mengjun; Weinthal, Erika; Patiño-Echeverri, Dalia; Deshusses, Marc A; Zou, Caineng; Ni, Yunyan; Vengosh, Avner

    2016-03-15

    Unconventional shale gas development holds promise for reducing the predominant consumption of coal and increasing the utilization of natural gas in China. While China possesses some of the most abundant technically recoverable shale gas resources in the world, water availability could still be a limiting factor for hydraulic fracturing operations, in addition to geological, infrastructural, and technological barriers. Here, we project the baseline water availability for the next 15 years in Sichuan Basin, one of the most promising shale gas basins in China. Our projection shows that continued water demand for the domestic sector in Sichuan Basin could result in high to extremely high water stress in certain areas. By simulating shale gas development and using information from current water use for hydraulic fracturing in Sichuan Basin (20,000-30,000 m(3) per well), we project that during the next decade water use for shale gas development could reach 20-30 million m(3)/year, when shale gas well development is projected to be most active. While this volume is negligible relative to the projected overall domestic water use of ∼36 billion m(3)/year, we posit that intensification of hydraulic fracturing and water use might compete with other water utilization in local water-stress areas in Sichuan Basin.

  1. Suspended sediments limit coral sperm availability

    PubMed Central

    Ricardo, Gerard F.; Jones, Ross J.; Clode, Peta L.; Humanes, Adriana; Negri, Andrew P.

    2015-01-01

    Suspended sediment from dredging activities and natural resuspension events represent a risk to the reproductive processes of coral, and therefore the ongoing maintenance of reefal populations. To investigate the underlying mechanisms that could reduce the fertilisation success in turbid water, we conducted several experiments exposing gametes of the corals Acropora tenuis and A. millepora to two sediment types. Sperm limitation was identified in the presence of siliciclastic sediment (230 and ~700 mg L−1), with 2–37 fold more sperm required to achieve maximum fertilisation rates, when compared with sediment-free treatments. This effect was more pronounced at sub-optimum sperm concentrations. Considerable (>45%) decreases in sperm concentration at the water’s surface was recorded in the presence of siliciclastic sediment and a >20% decrease for carbonate sediment. Electron microscopy then confirmed sediment entangled sperm and we propose entrapment and sinking is the primary mechanism reducing sperm available to the egg. Longer exposure to suspended sediments and gamete aging further decreased fertilisation success when compared with a shorter exposure. Collectively, these findings demonstrate that high concentrations of suspended sediments effectively remove sperm from the water’s surface during coral spawning events, reducing the window for fertilisation with potential subsequent flow-on effects for recruitment. PMID:26659008

  2. Water availability and environmental temperature correlate with geographic variation in water balance in common lizards.

    PubMed

    Dupoué, Andréaz; Rutschmann, Alexis; Le Galliard, Jean François; Miles, Donald B; Clobert, Jean; DeNardo, Dale F; Brusch, George A; Meylan, Sandrine

    2017-12-01

    Water conservation strategies are well documented in species living in water-limited environments, but physiological adaptations to water availability in temperate climate environments are still relatively overlooked. Yet, temperate species are facing more frequent and intense droughts as a result of climate change. Here, we examined variation in field hydration state (plasma osmolality) and standardized evaporative water loss rate (SEWL) of adult male and pregnant female common lizards (Zootoca vivipara) from 13 natural populations with contrasting air temperature, air humidity, and access to water. We found different patterns of geographic variation between sexes. Overall, males were more dehydrated (i.e. higher osmolality) than pregnant females, which likely comes from differences in field behaviour and water intake since the rate of SEWL was similar between sexes. Plasma osmolality and SEWL rate were positively correlated with environmental temperature in males, while plasma osmolality in pregnant females did not correlate with environmental conditions, reproductive stage or reproductive effort. The SEWL rate was significantly lower in populations without access to free standing water, suggesting that lizards can adapt or adjust physiology to cope with habitat dryness. Environmental humidity did not explain variation in water balance. We suggest that geographic variation in water balance physiology and behaviour should be taken account to better understand species range limits and sensitivity to climate change.

  3. Limits to the availability of groundwater in Africa

    NASA Astrophysics Data System (ADS)

    Edmunds, W. Mike

    2012-06-01

    shown, from numerous studies, to be almost entirely non-renewable, 'fossil' water, recharged under wetter early Holocene or late Pleistocene climates, prior to onset of a more arid climate around 4500 years BP (Edmunds et al 2004). Small amounts of modern recharge (for example in the Atlas Mountains or Tibesti) are insufficient to have an impact on the drawdown of distant well fields. It is critical, therefore, to base resource estimates for any development on knowledge of the locally renewable amounts from rainfall and to consider mining palaeo-reserves only as a last resort. Hydrogeological techniques are available to quantify modern recharge (Scanlon and Cook 2002, Scanlon et al 2006) and rates can vary widely according to rock type and landscape; reliance on modelled estimates alone could be misleading. Water quality is also a limiting factor in quantifying usable fresh groundwater storage. In addition to the regional or local problems caused by fluoride, in areas of East and West Africa (MacDonald et al 2012), salinity, above all, will restrict the total usable storage for domestic use and food production, most notably in semi-arid or arid areas. Groundwater salinity arises from various sources, including lithologies containing evaporite minerals, residual sea water (especially in continental coastal margins) and evapotranspiration. As a general rule, salinity increases with depth (older waters tend to more saline), but an additional problem arises where salinity has built up due to aridification over several millennia. Playas and sebkhats are surface expressions of this salinity accumulation from surface water or groundwater discharge, but clearance of native vegetation also increases recharge and leads to salinity increase (George et al 1997). Near-surface salt accumulation may be drawn down into cones of depression in areas of development. One of the largest artesian aquifers, the Continental Intercalaire of Algeria and Tunisia, has groundwater discharge with a

  4. Feedbacks between soil penetration resistance, root architecture and water uptake limit water accessibility and crop growth - A vicious circle.

    PubMed

    Colombi, Tino; Torres, Lorena Chagas; Walter, Achim; Keller, Thomas

    2018-06-01

    Water is the most limiting resource for global crop production. The projected increase of dry spells due to climate change will further increase the problem of water limited crop yields. Besides low water abundance and availability, water limitations also occur due to restricted water accessibility. Soil penetration resistance, which is largely influenced by soil moisture, is the major soil property regulating root elongation and water accessibility. Until now the interactions between soil penetration resistance, root system properties, water uptake and crop productivity are rarely investigated. In the current study we quantified how interactive effects between soil penetration resistance, root architecture and water uptake affect water accessibility and crop productivity in the field. Maize was grown on compacted and uncompacted soil that was either tilled or remained untilled after compaction, which resulted in four treatments with different topsoil penetration resistance. Higher topsoil penetration resistance caused root systems to be shallower. This resulted in increased water uptake from the topsoil and hence topsoil drying, which further increased the penetration resistance in the uppermost soil layer. As a consequence of this feedback, root growth into deeper soil layers, where water would have been available, was reduced and plant growth decreased. Our results demonstrate that soil penetration resistance, root architecture and water uptake are closely interrelated and thereby determine the potential of plants to access soil water pools. Hence, these interactions and their feedbacks on water accessibility and crop productivity have to be accounted for when developing strategies to alleviate water limitations in cropping systems. Copyright © 2018 Elsevier B.V. All rights reserved.

  5. Mapping water availability, cost and projected consumptive use in the eastern United States with comparisons to the west

    NASA Astrophysics Data System (ADS)

    Tidwell, Vincent C.; Moreland, Barbie D.; Shaneyfelt, Calvin R.; Kobos, Peter

    2018-01-01

    The availability of freshwater supplies to meet future demand is a growing concern. Water availability metrics are needed to inform future water development decisions. With the help of water managers, water availability was mapped for over 1300 watersheds throughout the 31 contiguous states in the eastern US complimenting a prior study of the west. The compiled set of water availability data is unique in that it considers multiple sources of water (fresh surface and groundwater, wastewater and brackish groundwater); accommodates institutional controls placed on water use; is accompanied by cost estimates to access, treat and convey each unique source of water; and is compared to projected future growth in consumptive water use to 2030. Although few administrative limits have been set on water availability in the east, water managers have identified 315 fresh surface water and 398 fresh groundwater basins (with 151 overlapping basins) as areas of concern (AOCs) where water supply challenges exist due to drought related concerns, environmental flows, groundwater overdraft, or salt water intrusion. This highlights a difference in management where AOCs are identified in the east which simply require additional permitting, while in the west strict administrative limits are established. Although the east is generally considered ‘water rich’ roughly a quarter of the basins were identified as AOCs; however, this is still in strong contrast to the west where 78% of the surface water basins are operating at or near their administrative limit. Little effort was noted on the part of eastern or western water managers to quantify non-fresh water resources.

  6. Ground-Water Availability in the United States

    USGS Publications Warehouse

    Reilly, Thomas E.; Dennehy, Kevin F.; Alley, William M.; Cunningham, William L.

    2008-01-01

    Ground water is among the Nation's most important natural resources. It provides half our drinking water and is essential to the vitality of agriculture and industry, as well as to the health of rivers, wetlands, and estuaries throughout the country. Large-scale development of ground-water resources with accompanying declines in ground-water levels and other effects of pumping has led to concerns about the future availability of ground water to meet domestic, agricultural, industrial, and environmental needs. The challenges in determining ground-water availability are many. This report examines what is known about the Nation's ground-water availability and outlines a program of study by the U.S. Geological Survey Ground-Water Resources Program to improve our understanding of ground-water availability in major aquifers across the Nation. The approach is designed to provide useful regional information for State and local agencies who manage ground-water resources, while providing the building blocks for a national assessment. The report is written for a wide audience interested or involved in the management, protection, and sustainable use of the Nation's water resources.

  7. Lunchtime School Water Availability and Water Consumption among California Adolescents

    PubMed Central

    Bogart, Laura M.; Babey, Susan H.; Patel, Anisha I.; Wang, Pan; Schuster, Mark A.

    2015-01-01

    Purpose To examine the potential impact of California SB1413, which required school districts to provide free, fresh drinking water during mealtimes in food service areas by July 1, 2011, on greater water consumption among California adolescents. Methods Data were drawn from the 2012 and 2013 state-representative California Health Interview Survey. A total of 2,665 adolescents aged 12-17 were interviewed regarding their water consumption and availability of free water during lunchtime at their school. Results Three-fourths reported that their school provided free water at lunchtime, mainly via fountains. In a multivariate model that controlled for age, gender, income, race/ethnicity, BMI, and school type, adolescents in schools that provided free water consumed significantly more water than adolescents who reported that water was not available, b (SE) = 0.67 (0.28), p = .02. School water access did not significantly vary across the two years. Conclusions Lunchtime school water availability was related to water consumption, but a quarter of adolescents reported that their school did not provide free water at lunch. Future research should explore what supports and inducements might facilitate provision of drinking water during school mealtimes. PMID:26552740

  8. Fraser River watershed, Colorado : assessment of available water-quantity and water-quality data through water year 1997

    USGS Publications Warehouse

    Apodaca, Lori Estelle; Bails, Jeffrey B.

    1999-01-01

    The water-quantity and water-quality data for the Fraser River watershed through water year 1997 were compiled for ground-water and surface-water sites. In order to assess the water-quality data, the data were related to land use/land cover in the watershed. Data from 81 water-quantity and water-quality sites, which consisted of 9 ground-water sites and 72 surface-water sites, were available for analysis. However, the data were limited and frequently contained only one or two water-quality analyses per site.The Fraser River flows about 28 miles from its headwaters at the Continental Divide to the confluence with the Colorado River. Ground-water resources in the watershed are used for residential and municipal drinking-water supplies. Surface water is available for use, but water diversions in the upper parts of the watershed reduce the flow in the river. Land use/land cover in the watershed is predominantly forested land, but increasing urban development has the potential to affect the quantity and quality of the water resources.Analysis of the limited ground-water data in the watershed indicates that changes in the land use/land cover affect the shallow ground-water quality. Water-quality data from eight shallow monitoring wells in the alluvial aquifer show that iron and manganese concentrations exceeded the U.S. Environmental Protection Agency secondary maximum contaminant level. Radon concentrations from these monitoring wells exceeded the U.S. Environmental Protection Agency proposed maximum contaminant level. The proposed radon contaminant level is currently being revised. The presence of volatile organic compounds at two monitoring wells in the watershed indicates that land use affects the shallow ground water. In addition, bacteria detected in three samples are at concentrations that would be a concern for public health if the water was to be used as a drinking supply. Methylene blue active substances were detected in the ground water at some sites and are a

  9. Mapping water availability, cost and projected consumptive use in the Eastern United States with comparisons to the West

    DOE PAGES

    Tidwell, Vincent; Moreland, Barbara D.; Shaneyfelt, Calvin; ...

    2017-11-08

    The availability of freshwater supplies to meet future demand is a growing concern. Water availability metrics are needed to inform future water development decisions. Furthermore, with the help of water managers, water availability was mapped for over 1300 watersheds throughout the 31-contiguous states in the eastern U.S. complimenting a prior study of the west. The compiled set of water availability data is unique in that it considers multiple sources of water (fresh surface and groundwater, wastewater and brackish groundwater); accommodates institutional controls placed on water use; is accompanied by cost estimates to access, treat and convey each unique source ofmore » water, and; is compared to projected future growth in consumptive water use to 2030. Although few administrative limits have been set on water availability in the east, water managers have identified 315 fresh surface water and 398 fresh groundwater basins (with 151 overlapping basins) as Areas of Concern (AOCs) where water supply challenges exist due to drought related concerns, environmental flows, groundwater overdraft, or salt water intrusion. This highlights a difference in management where AOCs are identified in the east which simply require additional permitting, while in the west strict administrative limits are established. Although the east is generally considered "water rich" roughly a quarter of the basins were identified as AOCs; however, this is still in strong contrast to the west where 78% of the surface water basins are operating at or near their administrative limit. There was little effort noted on the part of eastern or western water managers to quantify non-fresh water resources.« less

  10. Mapping water availability, cost and projected consumptive use in the Eastern United States with comparisons to the West

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

    Tidwell, Vincent; Moreland, Barbara D.; Shaneyfelt, Calvin

    The availability of freshwater supplies to meet future demand is a growing concern. Water availability metrics are needed to inform future water development decisions. Furthermore, with the help of water managers, water availability was mapped for over 1300 watersheds throughout the 31-contiguous states in the eastern U.S. complimenting a prior study of the west. The compiled set of water availability data is unique in that it considers multiple sources of water (fresh surface and groundwater, wastewater and brackish groundwater); accommodates institutional controls placed on water use; is accompanied by cost estimates to access, treat and convey each unique source ofmore » water, and; is compared to projected future growth in consumptive water use to 2030. Although few administrative limits have been set on water availability in the east, water managers have identified 315 fresh surface water and 398 fresh groundwater basins (with 151 overlapping basins) as Areas of Concern (AOCs) where water supply challenges exist due to drought related concerns, environmental flows, groundwater overdraft, or salt water intrusion. This highlights a difference in management where AOCs are identified in the east which simply require additional permitting, while in the west strict administrative limits are established. Although the east is generally considered "water rich" roughly a quarter of the basins were identified as AOCs; however, this is still in strong contrast to the west where 78% of the surface water basins are operating at or near their administrative limit. There was little effort noted on the part of eastern or western water managers to quantify non-fresh water resources.« less

  11. Lunchtime School Water Availability and Water Consumption Among California Adolescents.

    PubMed

    Bogart, Laura M; Babey, Susan H; Patel, Anisha I; Wang, Pan; Schuster, Mark A

    2016-01-01

    To examine the potential impact of California SB 1413, which required school districts to provide free, fresh drinking water during mealtimes in food service areas by July 1, 2011, on greater water consumption among California adolescents. Data were drawn from the 2012 and 2013 state-representative California Health Interview Survey. A total of 2,665 adolescents aged 12-17 years were interviewed regarding their water consumption and availability of free water during lunchtime at their school. Three-fourths reported that their school provided free water at lunchtime, mainly via fountains. In a multivariate model that controlled for age, gender, income, race/ethnicity, body mass index, and school type, adolescents in schools that provided free water consumed significantly more water than adolescents who reported that water was not available, bivariate (standard error) = .67 (.28), p = .02. School water access did not significantly vary across the 2 years. Lunchtime school water availability was related to water consumption, but a quarter of adolescents reported that their school did not provide free water at lunch. Future research should explore what supports and inducements might facilitate provision of drinking water during school mealtimes. Copyright © 2016 Society for Adolescent Health and Medicine. All rights reserved.

  12. Dynamic aspects of soil water availability for isohydric plants: Focus on root hydraulic resistances

    NASA Astrophysics Data System (ADS)

    Couvreur, V.; Vanderborght, J.; Draye, X.; Javaux, M.

    2014-11-01

    Soil water availability for plant transpiration is a key concept in agronomy. The objective of this study is to revisit this concept and discuss how it may be affected by processes locally influencing root hydraulic properties. A physical limitation to soil water availability in terms of maximal flow rate available to plant leaves (Qavail) is defined. It is expressed for isohydric plants, in terms of plant-centered variables and properties (the equivalent soil water potential sensed by the plant, ψs eq; the root system equivalent conductance, Krs; and a threshold leaf water potential, ψleaf lim). The resulting limitation to plant transpiration is compared to commonly used empirical stress functions. Similarities suggest that the slope of empirical functions might correspond to the ratio of Krs to the plant potential transpiration rate. The sensitivity of Qavail to local changes of root hydraulic conductances in response to soil matric potential is investigated using model simulations. A decrease of radial conductances when the soil dries induces earlier water stress, but allows maintaining higher night plant water potentials and higher Qavail during the last week of a simulated 1 month drought. In opposition, an increase of radial conductances during soil drying provokes an increase of hydraulic redistribution and Qavail at short term. This study offers a first insight on the effect of dynamic local root hydraulic properties on soil water availability. By better understanding complex interactions between hydraulic processes involved in soil-plant hydrodynamics, better prospects on how root hydraulic traits mitigate plant water stress might be achieved.

  13. Water Availability and Use Pilot-A multiscale assessment in the U.S. Great Lakes Basin

    USGS Publications Warehouse

    Reeves, Howard W.

    2011-01-01

    Beginning in 2005, water availability and use were assessed for the U.S. part of the Great Lakes Basin through the Great Lakes Basin Pilot of a U.S. Geological Survey (USGS) national assessment of water availability and use. The goals of a national assessment of water availability and use are to clarify our understanding of water-availability status and trends and improve our ability to forecast the balance between water supply and demand for future economic and environmental uses. This report outlines possible approaches for full-scale implementation of such an assessment. As such, the focus of this study was on collecting, compiling, and analyzing a wide variety of data to define the storage and dynamics of water resources and quantify the human demands on water in the Great Lakes region. The study focused on multiple spatial and temporal scales to highlight not only the abundant regional availability of water but also the potential for local shortages or conflicts over water. Regional studies provided a framework for understanding water resources in the basin. Subregional studies directed attention to varied aspects of the water-resources system that would have been difficult to assess for the whole region because of either data limitations or time limitations for the project. The study of local issues and concerns was motivated by regional discussions that led to recent legislative action between the Great Lakes States and regional cooperation with the Canadian Great Lakes Provinces. The multiscale nature of the study findings challenges water-resource managers and the public to think about regional water resources in an integrated way and to understand how future changes to the system-driven by human uses, climate variability, or land-use change-may be accommodated by informed water-resources management.

  14. 25 CFR 137.2 - Availability of water.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Availability of water. 137.2 Section 137.2 Indians BUREAU... COSTS, SAN CARLOS INDIAN IRRIGATION PROJECT, ARIZONA § 137.2 Availability of water. Pursuant to section... notice to announce when water is actually available for lands in private ownership under the project and...

  15. 25 CFR 137.2 - Availability of water.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Availability of water. 137.2 Section 137.2 Indians BUREAU... COSTS, SAN CARLOS INDIAN IRRIGATION PROJECT, ARIZONA § 137.2 Availability of water. Pursuant to section... notice to announce when water is actually available for lands in private ownership under the project and...

  16. 25 CFR 137.2 - Availability of water.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Availability of water. 137.2 Section 137.2 Indians BUREAU... COSTS, SAN CARLOS INDIAN IRRIGATION PROJECT, ARIZONA § 137.2 Availability of water. Pursuant to section... notice to announce when water is actually available for lands in private ownership under the project and...

  17. 25 CFR 137.2 - Availability of water.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Availability of water. 137.2 Section 137.2 Indians BUREAU... COSTS, SAN CARLOS INDIAN IRRIGATION PROJECT, ARIZONA § 137.2 Availability of water. Pursuant to section... notice to announce when water is actually available for lands in private ownership under the project and...

  18. Regional Responses to Constrained Water Availability

    NASA Astrophysics Data System (ADS)

    Cui, Y.; Calvin, K. V.; Hejazi, M. I.; Clarke, L.; Kim, S. H.; Patel, P.

    2017-12-01

    There have been many concerns about water as a constraint to agricultural production, electricity generation, and many other human activities in the coming decades. Nevertheless, how different countries/economies would respond to such constraints has not been explored. Here, we examine the responding mechanism of binding water availability constraints at the water basin level and across a wide range of socioeconomic, climate and energy technology scenarios. Specifically, we look at the change in water withdrawals between energy, land-use and other sectors within an integrated framework, by using the Global Change Assessment Model (GCAM) that also endogenizes water use and allocation decisions based on costs. We find that, when water is taken into account as part of the production decision-making, countries/basins in general fall into three different categories, depending on the change of water withdrawals and water re-allocation between sectors. First, water is not a constraining factor for most of the basins. Second, advancements in water-saving technologies of the electricity generation cooling systems are sufficient of reducing water withdrawals to meet binding water availability constraints, such as in China and the EU-15. Third, water-saving in the electricity sector alone is not sufficient and thus cannot make up the lowered water availability from the binding case; for example, many basins in Pakistan, Middle East and India have to largely reduce irrigated water withdrawals by either switching to rain-fed agriculture or reducing production. The dominant responding strategy for individual countries/basins is quite robust across the range of alternate scenarios that we test. The relative size of water withdrawals between energy and agriculture sectors is one of the most important factors that affect the dominant mechanism.

  19. Water chemistry, seepage investigation, streamflow, reservoir storage, and annual availability of water for the San Juan-Chama Project, northern New Mexico, 1942-2010

    USGS Publications Warehouse

    McKean, Sarah E.; Anderholm, Scott K.

    2014-01-01

    at Azotea Tunnel Outlet occurred from May through June, with a median duration of slightly longer than a month. Years with higher maximum daily streamflow generally are associated with higher annual streamflow than years with lower maximum daily streamflow. The amount of water that can be diverted for the SJCP is controlled by the availability of streamflow and is limited by several factors including legal limits for diversion, limits from the SJCP infrastructure including the size of the diversion dams and tunnels, the capacity of Heron Reservoir, and operational constraints that limit when water can be diverted. The average annual streamflow at Azotea Tunnel Outlet was 94,710 acre-feet, and the annual streamflow at Azotea Tunnel Outlet was approximately 75 percent of the annual streamflow available for the SJCP. The average annual percentage of available streamflow not diverted for the SJCP was 14 percent because of structural limitations of the capacity of infrastructure, 1 percent because of limitations of the reservoir storage capacity, and 29 percent because of the limitations from operations. For most years, the annual available streamflow not diverted for unknown reasons exceeded the sum of the water not diverted because of structural, capacity, and operational limitations.

  20. Limitations to postfire seedling establishment: The role of seeding technology, water availability, and invasive plant abundance

    Treesearch

    Jeremy J. James; Tony Svejcar

    2010-01-01

    Seeding rangeland following wildfire is a central tool managers use to stabilize soils and inhibit the spread of invasive plants. Rates of successful seeding on arid rangeland, however, are low. The objective of this study was to determine the degree to which water availability, invasive plant abundance, and seeding technology influence postfire seedling establishment...

  1. 42 CFR 440.255 - Limited services available to certain aliens.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Limited services available to certain aliens. 440... Limits Applicable to All Services § 440.255 Limited services available to certain aliens. (a) FFP for services. FFP is available for services provided to aliens described in this section which are necessary to...

  2. 42 CFR 440.255 - Limited services available to certain aliens.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false Limited services available to certain aliens. 440... Limits Applicable to All Services § 440.255 Limited services available to certain aliens. (a) FFP for services. FFP is available for services provided to aliens described in this section which are necessary to...

  3. 42 CFR 440.255 - Limited services available to certain aliens.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Limited services available to certain aliens. 440... Limits Applicable to All Services § 440.255 Limited services available to certain aliens. (a) FFP for services. FFP is available for services provided to aliens described in this section which are necessary to...

  4. 42 CFR 440.255 - Limited services available to certain aliens.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false Limited services available to certain aliens. 440... Limits Applicable to All Services § 440.255 Limited services available to certain aliens. (a) FFP for services. FFP is available for services provided to aliens described in this section which are necessary to...

  5. 42 CFR 440.255 - Limited services available to certain aliens.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 4 2012-10-01 2012-10-01 false Limited services available to certain aliens. 440... Limits Applicable to All Services § 440.255 Limited services available to certain aliens. (a) FFP for services. FFP is available for services provided to aliens described in this section which are necessary to...

  6. The ecohydrology of water limited landscapes

    NASA Astrophysics Data System (ADS)

    Huxman, T. E.

    2011-12-01

    Developing a mechanistic understanding of the coupling of ecological and hydrological systems is crucial for understanding the land-surface response of large areas of the globe to changes in climate. The distribution of biodiversity, the quantity and quality of streamflow, the biogeochemistry that constrains vegetation cover and production, and the stability of soil systems in watersheds are all functions of water-life coupling. Many key ecosystem services are governed by the dynamics of near-surface hydrology and biological feedbacks on the landscape occur through plant influence over available soil moisture. Thus, ecohydrology has tremendous potential to contribute to a predictive framework for understanding earth system dynamics. Despite the importance of such couplings and water as a major limiting resource in ecosystems throughout the globe, ecology still struggles with a mechanistic understanding of how changes in rainfall affect the biology of plants and microbes, or how changes in plant communities affect hydrological dynamics in watersheds. Part of the problem comes from our lack of understanding of how plants effectively partition available water among individuals in communities and how that modifies the physical environment, affecting additional resource availability and the passage of water along other hydrological pathways. The partitioning of evapotranspiration between transpiration by plants and evaporation from the soil surface is key to interrelated ecological, hydrological, and atmospheric processes and likely varies with vegetation structure and atmospheric dynamics. In addition, the vertical stratification of autotrophic and heterotrophic components in the soil profile, and the speed at which each respond to increased water, exert strong control over the carbon cycle. The magnitude of biosphere-atmosphere carbon exchange depends on the time-depth-distribution of soil moisture, a fundamental consequence of local precipitation pulse

  7. Unravelling the limits to tree height: a major role for water and nutrient trade-offs.

    PubMed

    Cramer, Michael D

    2012-05-01

    Competition for light has driven forest trees to grow exceedingly tall, but the lack of a single universal limit to tree height indicates multiple interacting environmental limitations. Because soil nutrient availability is determined by both nutrient concentrations and soil water, water and nutrient availabilities may interact in determining realised nutrient availability and consequently tree height. In SW Australia, which is characterised by nutrient impoverished soils that support some of the world's tallest forests, total [P] and water availability were independently correlated with tree height (r = 0.42 and 0.39, respectively). However, interactions between water availability and each of total [P], pH and [Mg] contributed to a multiple linear regression model of tree height (r = 0.72). A boosted regression tree model showed that maximum tree height was correlated with water availability (24%), followed by soil properties including total P (11%), Mg (10%) and total N (9%), amongst others, and that there was an interaction between water availability and total [P] in determining maximum tree height. These interactions indicated a trade-off between water and P availability in determining maximum tree height in SW Australia. This is enabled by a species assemblage capable of growing tall and surviving (some) disturbances. The mechanism for this trade-off is suggested to be through water enabling mass-flow and diffusive mobility of P, particularly of relatively mobile organic P, although water interactions with microbial activity could also play a role.

  8. Evolutionary speed limited by water in arid Australia.

    PubMed

    Goldie, Xavier; Gillman, Len; Crisp, Mike; Wright, Shane

    2010-09-07

    The covariation of biodiversity with climate is a fundamental pattern in nature. However, despite the ubiquity of this relationship, a consensus on the ultimate cause remains elusive. The evolutionary speed hypothesis posits direct mechanistic links between ambient temperature, the tempo of micro-evolution and, ultimately, species richness. Previous research has demonstrated faster rates of molecular evolution in warmer climates for a broad range of poikilothermic and homeothermic organisms, in both terrestrial and aquatic environments. In terrestrial systems, species richness increases with both temperature and water availability and the interaction of those terms: productivity. However, the influence of water availability as an independent variable on micro-evolutionary processes has not been examined previously. Here, using methodology that limits the potentially confounding role of cladogenetic and demographic processes, we report, to our knowledge, the first evidence that woody plants living in the arid Australian Outback are evolving more slowly than related species growing at similar latitudes in moist habitats on the mesic continental margins. These results support a modified evolutionary speed explanation for the relationship between the water-energy balance and plant diversity patterns.

  9. Feasibility of potable water generators to meet vessel numeric ballast water discharge limits.

    PubMed

    Albert, Ryan J; Viveiros, Edward; Falatko, Debra S; Tamburri, Mario N

    2017-07-15

    Ballast water is taken on-board vessels into ballast water tanks to maintain vessel draft, buoyancy, and stability. Unmanaged ballast water contains aquatic organisms that, when transported and discharged to non-native waters, may establish as invasive species. Technologies capable of achieving regulatory limits designed to decrease the likelihood of invasion include onboard ballast water management systems. However, to date, the treatment development and manufacturing marketplace is limited to large vessels with substantial ballast requirements. For smaller vessels or vessels with reduced ballast requirements, we evaluated the feasibility of meeting the discharge limits by generating ballast water using onboard potable water generators. Case studies and parametric analyses demonstrated the architectural feasibility of installing potable water generators onboard actual vessels with minimal impacts for most vessel types evaluated. Furthermore, land-based testing of a potable water generator demonstrated capability to meet current numeric discharge limits for living organisms in all size classes. Published by Elsevier Ltd.

  10. 46 CFR 76.10-3 - Water availability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall be...

  11. 46 CFR 76.10-3 - Water availability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall be...

  12. 46 CFR 76.10-3 - Water availability.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall be...

  13. 46 CFR 76.10-3 - Water availability.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall be...

  14. 46 CFR 76.10-3 - Water availability.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Water availability. 76.10-3 Section 76.10-3 Shipping... Fire Main System, Details § 76.10-3 Water availability. (a) On all vessels on an international voyage, regardless of the date of construction, water pressure from the firemain protecting enclosed spaces shall be...

  15. Shifts in water availability mediate plant-pollinator interactions.

    PubMed

    Gallagher, M Kate; Campbell, Diane R

    2017-07-01

    Altered precipitation patterns associated with anthropogenic climate change are expected to have many effects on plants and insect pollinators, but it is unknown if effects on pollination are mediated by changes in water availability. We tested the hypothesis that impacts of climate on plant-pollinator interactions operate through changes in water availability, and specifically that such effects occur through alteration of floral attractants. We manipulated water availability in two naturally occurring Mertensia ciliata (Boraginaceae) populations using water addition, water reduction and control plots and measured effects on vegetative and floral traits, pollinator visitation and seed set. While most floral trait values, including corolla size and nectar, increased linearly with increasing water availability, in this bumblebee-pollinated species, pollinator visitation peaked at intermediate water levels. Visitation also peaked at an intermediate corolla length, while its relationship to corolla width varied across sites. Seed set, however, increased linearly with water. These results demonstrate the potential for changes in water availability to impact plant-pollinator interactions through pollinator responses to differences in floral attractants, and that the effects of water on pollinator visitation can be nonlinear. Plant responses to changes in resource availability may be an important mechanism by which climate change will affect species interactions. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  16. Perceptions about availability and adequacy of drinking water in a large California school district.

    PubMed

    Patel, Anisha I; Bogart, Laura M; Uyeda, Kimberly E; Rabin, Alexa; Schuster, Mark A

    2010-03-01

    Concerns about the influence of sugar-sweetened beverage consumption on obesity have led experts to recommend that water be freely available in schools. We explored perceptions about the adequacy of drinking water provision in a large California school district to develop policies and programs to encourage student water consumption. From March to September 2007, we used semistructured interviews to ask 26 California key stakeholders - including school administrators and staff, health and nutrition agency representatives, and families - about school drinking water accessibility; attitudes about, facilitators of, and barriers to drinking water provision; and ideas for increasing water consumption. Interviews were analyzed to determine common themes. Although stakeholders said that water was available from school drinking fountains, they expressed concerns about the appeal, taste, appearance, and safety of fountain water and worried about the affordability and environmental effect of bottled water sold in schools. Stakeholders supported efforts to improve free drinking water availability in schools, but perceived barriers (eg, cost) and mistaken beliefs that regulations and beverage contracts prohibit serving free water may prevent schools from doing so. Some schools provide water through cold-filtered water dispensers and self-serve water coolers. This is the first study to explore stakeholder perceptions about the adequacy of drinking water in US schools. Although limited in scope, our study suggests that water available in at least some schools may be inadequate. Collaborative efforts among schools, communities, and policy makers are needed to improve school drinking water provision.

  17. Growth is required for perception of water availability to pattern root branches in plants.

    PubMed

    Robbins, Neil E; Dinneny, José R

    2018-01-23

    Water availability is a potent regulator of plant development and induces root branching through a process termed hydropatterning. Hydropatterning enables roots to position lateral branches toward regions of high water availability, such as wet soil or agar media, while preventing their emergence where water is less available, such as in air. The mechanism by which roots perceive the spatial distribution of water during hydropatterning is unknown. Using primary roots of Zea mays (maize) we reveal that developmental competence for hydropatterning is limited to the growth zone of the root tip. Past work has shown that growth generates gradients in water potential across an organ when asymmetries exist in the distribution of available water. Using mathematical modeling, we predict that substantial growth-sustained water potential gradients are also generated in the hydropatterning competent zone and that such biophysical cues inform the patterning of lateral roots. Using diverse chemical and environmental treatments we experimentally demonstrate that growth is necessary for normal hydropatterning of lateral roots. Transcriptomic characterization of the local response of tissues to a moist surface or air revealed extensive regulation of signaling and physiological pathways, some of which we show are growth-dependent. Our work supports a "sense-by-growth" mechanism governing hydropatterning, by which water availability cues are rendered interpretable through growth-sustained water movement. Copyright © 2018 the Author(s). Published by PNAS.

  18. Growth is required for perception of water availability to pattern root branches in plants

    PubMed Central

    2018-01-01

    Water availability is a potent regulator of plant development and induces root branching through a process termed hydropatterning. Hydropatterning enables roots to position lateral branches toward regions of high water availability, such as wet soil or agar media, while preventing their emergence where water is less available, such as in air. The mechanism by which roots perceive the spatial distribution of water during hydropatterning is unknown. Using primary roots of Zea mays (maize) we reveal that developmental competence for hydropatterning is limited to the growth zone of the root tip. Past work has shown that growth generates gradients in water potential across an organ when asymmetries exist in the distribution of available water. Using mathematical modeling, we predict that substantial growth-sustained water potential gradients are also generated in the hydropatterning competent zone and that such biophysical cues inform the patterning of lateral roots. Using diverse chemical and environmental treatments we experimentally demonstrate that growth is necessary for normal hydropatterning of lateral roots. Transcriptomic characterization of the local response of tissues to a moist surface or air revealed extensive regulation of signaling and physiological pathways, some of which we show are growth-dependent. Our work supports a “sense-by-growth” mechanism governing hydropatterning, by which water availability cues are rendered interpretable through growth-sustained water movement. PMID:29317538

  19. Water on Mars - Volatile history and resource availability

    NASA Technical Reports Server (NTRS)

    Jakosky, Bruce M.

    1990-01-01

    An attempt is made to define the available deposits of water in the near-surface region of Mars which will be available to human exploration missions. The Martian seasonal water cycle is reviewed, and geochemical and geological constraints on the availability of water are examined. It is concluded that the only sure source of water in amounts significant as a resource are in the polar ice deposits.

  20. Water-quality assessment of the Potomac River Basin: analysis of available pesticide data, 1972-1990

    USGS Publications Warehouse

    Zappia, Humbert; Fisher, Gary T.

    1997-01-01

    A study of available data for the period from 1972 to 1990 was conducted to characterize the occurrence and distribution of pesticides in sur-face water, bottom material, ground water, and fish tissue in the Potomac River Basin. The study was conducted by the Potomac River study unit of the U.S. Geological Survey?s National Water-Quality Assessment (NAWQA) program. Exist-ing data coverage was evaluated to guide future data-collection activities. Data from computer data bases and from published and unpublished reports were obtained from local, State, and Fed-eral agencies in the four Potomac River Basin states and the District of Columbia. Data are available for all environmental media, but geo-graphic and temporal coverage are limited. Clusters of data occur in the north-central parts of the basin, with numerous samples at discrete loca-tions in the Shenandoah and Monocacy River Basins, along the mainstem Potomac River, in the Washington, D.C., area, and in streams along the Potomac Estuary. Much of the available surface-water and bottom-material data are from the ear-lier years of the period of interest, the ground-water data are from the middle years, and the fish-tissue data are distributed over much of the period. Overall, temporal coverage is not sufficient for analysis of trends. Comparisons between different sample media are possible in some areas of the Potomac River Basin, particularly in the northern end of the Great Valley. Residual concentrations of some pesticides have been found in surface water, bottom mate-rial, ground water, and fish tissue. Samples have been analyzed for a total of at least 69 pesticides and related compounds in surface water, bottom material, ground water, and fish tissue. Most con-centrations of the pesticides analyzed during the period from 1972 to 1990 were less than or equal to reporting limits. For surface-water samples, 13 out of 41 pes-ticides and related compounds analyzed had concentrations equal to or greater than the

  1. Water Availability and Management of Water Resources

    EPA Science Inventory

    One of the most pressing national and global issues is the availability of freshwater due to global climate change, energy scarcity issues and the increase in world population and accompanying economic growth. Estimates of water supplies and flows through the world's hydrologic c...

  2. Analysis of the Development of Available Soil Water Storage in the Nitra River Catchment

    NASA Astrophysics Data System (ADS)

    Tárník, Andrej; Leitmanová, Mária

    2017-10-01

    World is changing dramatically. Every sphere of our life is influenced by global climate changes, including agriculture sector. Rising air temperature and temporal variability of rainfall are crucial outcomes of climate changes for agricultural activities. Main impact of these outcomes on agriculture is the change of soil water amount. Soil water is an exclusive resource of water for plants. Changes of soil water storage are sensed very sensitively by farmers. Development of soil water storage was analysed in this paper. The Nitra River catchment is covered by nets of hydrological and meteorological stations of Department of Biometeorology and Hydrology, Slovak University of Agriculture in Nitra. Quantity of available soil water storage for plants was calculated every month in the years from 2013 to 2016. Calculations were done based on real measurements for soil horizon 0-30 cm. Ratio between a real available soil water storage and a potential available soil water storage was specified. Amount of potential available soil water storage was derived by retention curves of soil samples. Map of risk areas was created in GIS in pursuance of these calculations. We can see the negative trends of available soil water storage in years 2015 and 2016. Main addition of this paper is a selection of areas where soil moisture is a limiting factor of agriculture. In these areas, it is necessary to do the mitigation measures for sustainable development of agricultural activities.

  3. A Versatile Phenotyping System and Analytics Platform Reveals Diverse Temporal Responses to Water Availability in Setaria.

    PubMed

    Fahlgren, Noah; Feldman, Maximilian; Gehan, Malia A; Wilson, Melinda S; Shyu, Christine; Bryant, Douglas W; Hill, Steven T; McEntee, Colton J; Warnasooriya, Sankalpi N; Kumar, Indrajit; Ficor, Tracy; Turnipseed, Stephanie; Gilbert, Kerrigan B; Brutnell, Thomas P; Carrington, James C; Mockler, Todd C; Baxter, Ivan

    2015-10-05

    Phenotyping has become the rate-limiting step in using large-scale genomic data to understand and improve agricultural crops. Here, the Bellwether Phenotyping Platform for controlled-environment plant growth and automated multimodal phenotyping is described. The system has capacity for 1140 plants, which pass daily through stations to record fluorescence, near-infrared, and visible images. Plant Computer Vision (PlantCV) was developed as open-source, hardware platform-independent software for quantitative image analysis. In a 4-week experiment, wild Setaria viridis and domesticated Setaria italica had fundamentally different temporal responses to water availability. While both lines produced similar levels of biomass under limited water conditions, Setaria viridis maintained the same water-use efficiency under water replete conditions, while Setaria italica shifted to less efficient growth. Overall, the Bellwether Phenotyping Platform and PlantCV software detected significant effects of genotype and environment on height, biomass, water-use efficiency, color, plant architecture, and tissue water status traits. All ∼ 79,000 images acquired during the course of the experiment are publicly available. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  4. Water availability and management for food security

    USDA-ARS?s Scientific Manuscript database

    Food security is directly linked to water security for food production. Water availability for crop production will be dependent upon precipitation or irrigation, soil water holding capacity, and crop water demand. The linkages among these components in rainfed agricultural systems shows the impact ...

  5. Evolutionary speed limited by water in arid Australia

    PubMed Central

    Goldie, Xavier; Gillman, Len; Crisp, Mike; Wright, Shane

    2010-01-01

    The covariation of biodiversity with climate is a fundamental pattern in nature. However, despite the ubiquity of this relationship, a consensus on the ultimate cause remains elusive. The evolutionary speed hypothesis posits direct mechanistic links between ambient temperature, the tempo of micro-evolution and, ultimately, species richness. Previous research has demonstrated faster rates of molecular evolution in warmer climates for a broad range of poikilothermic and homeothermic organisms, in both terrestrial and aquatic environments. In terrestrial systems, species richness increases with both temperature and water availability and the interaction of those terms: productivity. However, the influence of water availability as an independent variable on micro-evolutionary processes has not been examined previously. Here, using methodology that limits the potentially confounding role of cladogenetic and demographic processes, we report, to our knowledge, the first evidence that woody plants living in the arid Australian Outback are evolving more slowly than related species growing at similar latitudes in moist habitats on the mesic continental margins. These results support a modified evolutionary speed explanation for the relationship between the water-energy balance and plant diversity patterns. PMID:20410038

  6. Assessment of the SWAT model to simulate a watershed with limited available data in the Pampas region, Argentina.

    PubMed

    Romagnoli, Martín; Portapila, Margarita; Rigalli, Alfredo; Maydana, Gisela; Burgués, Martín; García, Carlos M

    2017-10-15

    Argentina has been among the world leaders in the production and export of agricultural products since the 1990s. The Carcarañá River Lower Basin (CRLB), a cropland of the Pampas region supplied by extensive rainfall, is located in an area with few streamgauging and other hydrologic/water-quality stations. Therefore, limited hydrologic data are available resulting in limited water-resources assessment. This work explores the application of Soil and Water Assessment Tool (SWAT) model to the CRLB in the Santa Fe province of the Pampas region. The analysis of field and remote-sensing data characterizing hydrology, water quality, soil types, land use/land cover, management practices, and crop yield, guarantee a comprehensive SWAT modeling approach. A combined manual and automated calibration and validation process incorporating sensitivity and uncertainty analysis is performed using information concerning interior watershed processes. Eleven N/P fertilizer rates are selected to simulate the impact of N fertilizer on crop yield, plant uptake, as well as runoff and leaching losses. Different indices (partial factor productivity, agronomic efficiency, apparent crop recovery efficiency of applied nutrient, internal utilization efficiency, and physiological efficiency) are considered to assess nitrogen-use efficiency. The overall quality of the fit is satisfactory considering the input data limitations. This work provides, for the first time in Argentina, a reliable tool to simulate yield response to soil quality and water availability capable to meet defined environmental targets to support decision making on planning public policies and private activities on the Pampas region. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Availability of water in Kalamazoo County, southwestern Michigan

    USGS Publications Warehouse

    Allen, William Burrows; Miller, John B.; Wood, Warren W.

    1972-01-01

    of the utmost importance. Levels at Crooked and Eagle Lakes have been maintained by pumping from lower aquifers. Diversion of water from Gourdneck Creek to West and Austin Lakes has helped in maintaining levels. Several relatively undeveloped lakes could be utilized as reservoirs whose storage could be used to augment streamflow or for water supply.Water in streams is generally of good chemical quality; however, several streams, including the Kalamazoo River downstream from Kalamazoo, have been degraded by municipal and industrial waste disposal. Water in the lakes is generally of good chemical quality with the exception of Barton Lake, which has been degraded by waste disposal. There is sufficient surface water available in Kalamazoo County to meet requirements for development of large quantities of water. The total available supply (average discharge of a stream) is about 680 mgd (million gallons per day). The dependable supply (7-day Q2, or average 7-day low flow having a recurrence interval of 2 years) is about 303 mgd. By developing artificial recharge facilities, surface runoff during winter and spring could be utilized to recharge ground-water reservoirs. Surface-water withdrawal in 1966 was about 58 mgd, of which 33 mgd was withdrawn from the Kalamazoo River. The quantity of water now being withdrawn from the ground and surface sources is small compared to the total that may be obtained in the area through full utilization of these resources. Mathematical models were used to simulate hydrologic conditions in the ground-water reservoirs and to evaluate maximum drawdowns for periods of little or no recharge. The practical limits of development as determined for the ground-water reservoirs are estimated to be at the following average withdrawal rates: Kalamazoo, 39 .mgd; Schoolcraft, 17 mgd; Kalamazoo-Portage, 24 mgd; and several small reservoirs, 67 mgd. These total 147 mgd. Further development would require additional artificial recharge facilities. Average

  8. Proposing water balance method for water availability estimation in Indonesian regional spatial planning

    NASA Astrophysics Data System (ADS)

    Juniati, A. T.; Sutjiningsih, D.; Soeryantono, H.; Kusratmoko, E.

    2018-01-01

    The water availability (WA) of a region is one of important consideration in both the formulation of spatial plans and the evaluation of the effectiveness of actual land use in providing sustainable water resources. Information on land-water needs vis-a-vis their availability in a region determines the state of the surplus or deficit to inform effective land use utilization. How to calculate water availability have been described in the Guideline in Determining the Carrying Capacity of the Environment in Regional Spatial Planning. However, the method of determining the supply and demand of water on these guidelines is debatable since the determination of WA in this guideline used a rational method. The rational method is developed the basis for storm drain design practice and it is essentially a peak discharge method peak discharge calculation method. This paper review the literature in methods of water availability estimation which is described descriptively, and present arguments to claim that water balance method is a more fundamental and appropriate tool in water availability estimation. A better water availability estimation method would serve to improve the practice in preparing formulations of Regional Spatial Plan (RSP) as well as evaluating land use capacity in providing sustainable water resources.

  9. Modeling Limited Foresight in Water Management Systems

    NASA Astrophysics Data System (ADS)

    Howitt, R.

    2005-12-01

    The inability to forecast future water supplies means that their management inevitably occurs under situations of limited foresight. Three modeling problems arise, first what type of objective function is a manager with limited foresight optimizing? Second how can we measure these objectives? Third can objective functions that incorporate uncertainty be integrated within the structure of optimizing water management models? The paper reviews the concepts of relative risk aversion and intertemporal substitution that underlie stochastic dynamic preference functions. Some initial results from the estimation of such functions for four different dam operations in northern California are presented and discussed. It appears that the path of previous water decisions and states influences the decision-makers willingness to trade off water supplies between periods. A compromise modeling approach that incorporates carry-over value functions under limited foresight within a broader net work optimal water management model is developed. The approach uses annual carry-over value functions derived from small dimension stochastic dynamic programs embedded within a larger dimension water allocation network. The disaggregation of the carry-over value functions to the broader network is extended using the space rule concept. Initial results suggest that the solution of such annual nonlinear network optimizations is comparable to, or faster than, the solution of linear network problems over long time series.

  10. Influence of iron availability on nutrient consumption ratio of diatoms in oceanic waters

    NASA Astrophysics Data System (ADS)

    Takeda, Shigenobu

    1998-06-01

    The major nutrients (nitrate, phosphate and silicate) needed for phytoplankton growth are abundant in the surface waters of the subarctic Pacific, equatorial Pacific and Southern oceans, but this growth is limited by the availability of iron. Under iron-deficient conditions, phytoplankton exhibit reduced uptake of nitrate and lower cellular levels of carbon, nitrogen and phosphorus. Here I describe seawater and culture experiments which show that iron limitation can also affect the ratio of consumed silicate to nitrate and phosphate. In iron-limited waters from all three of the aforementioned environments, addition of iron to phytoplankton assemblages in incubation bottles halved the silicate:nitrate and silicate:phosphate consumption ratios, in spite of the preferential growth of diatoms (silica-shelled phytoplankton). The nutrient consumption ratios of the phytoplankton assemblage from the Southern Ocean were similar to those of an iron-deficient laboratory culture of Antarctic diatoms, which exhibit increased cellular silicon or decreased cellular nitrogen and phosphorus in response to iron limitation. Iron limitation therefore increases the export of biogenic silicon, relative to nitrogen and phosphorus, from the surface to deeper waters. These findings suggest how the sedimentary records of carbon and silicon deposition in the glacial Southern Ocean can be consistent with the idea that changes in productivity, and thus in drawdown of atmospheric CO2, during the last glaciation were stimulated by changes in iron inputs from atmospheric dust.

  11. Effect of water availability on tolerance of leaf damage in tall morning glory, Ipomoea purpurea

    NASA Astrophysics Data System (ADS)

    Atala, Cristian; Gianoli, Ernesto

    2009-03-01

    Resource availability may limit plant tolerance of herbivory. To predict the effect of differential resource availability on plant tolerance, the limiting resource model (LRM) considers which resource limits plant fitness and which resource is mostly affected by herbivore damage. We tested the effect of experimental drought on tolerance of leaf damage in Ipomoea purpurea, which is naturally exposed to both leaf damage and summer drought. To seek mechanistic explanations, we also measured several morphological, allocation and gas exchange traits. In this case, LRM predicts that tolerance would be the same in both water treatments. Plants were assigned to a combination of two water treatments (control and low water) and two damage treatments (50% defoliation and undamaged). Plants showed tolerance of leaf damage, i.e., a similar number of fruits were produced by damaged and undamaged plants, only in control water. Whereas experimental drought affected all plant traits, leaf damage caused plants to show a greater leaf trichome density and reduced shoot biomass, but only in low water. It is suggested that the reduced fitness (number of fruits) of damaged plants in low water was mediated by the differential reduction of shoot biomass, because the number of fruits per shoot biomass was similar in damaged and undamaged plants. Alternative but less likely explanations include the opposing direction of functional responses to drought and defoliation, and resource costs of the damage-induced leaf trichome density. Our results somewhat challenge the LRM predictions, but further research including field experiments is needed to validate some of the preliminary conclusions drawn.

  12. The potential impacts of biomass feedstock production on water resource availability.

    PubMed

    Stone, K C; Hunt, P G; Cantrell, K B; Ro, K S

    2010-03-01

    Biofuels are a major topic of global interest and technology development. Whereas bioenergy crop production is highly dependent on water, bioenergy development requires effective allocation and management of water. The objectives of this investigation were to assess the bioenergy production relative to the impacts on water resource related factors: (1) climate and weather impact on water supplies for biomass production; (2) water use for major bioenergy crop production; and (3) potential alternatives to improve water supplies for bioenergy. Shifts to alternative bioenergy crops with greater water demand may produce unintended consequences for both water resources and energy feedstocks. Sugarcane and corn require 458 and 2036 m(3) water/m(3) ethanol produced, respectively. The water requirements for corn grain production to meet the US-DOE Billion-Ton Vision may increase approximately 6-fold from 8.6 to 50.1 km(3). Furthermore, climate change is impacting water resources throughout the world. In the western US, runoff from snowmelt is occurring earlier altering the timing of water availability. Weather extremes, both drought and flooding, have occurred more frequently over the last 30 years than the previous 100 years. All of these weather events impact bioenergy crop production. These events may be partially mitigated by alternative water management systems that offer potential for more effective water use and conservation. A few potential alternatives include controlled drainage and new next-generation livestock waste treatment systems. Controlled drainage can increase water available to plants and simultaneously improve water quality. New livestock waste treatments systems offer the potential to utilize treated wastewater to produce bioenergy crops. New technologies for cellulosic biomass conversion via thermochemical conversion offer the potential for using more diverse feedstocks with dramatically reduced water requirements. The development of bioenergy

  13. Is the available cropland and water enough for food demand? A global perspective of the Land-Water-Food nexus

    NASA Astrophysics Data System (ADS)

    Ibarrola-Rivas, M. J.; Granados-Ramírez, R.; Nonhebel, S.

    2017-12-01

    Land and water are essential local resources for food production but are limited. The main drivers of increasing food demand are population growth and dietary changes, which depend on the socioeconomic situation of the population. These two factors affect the availability of local resources: population growth reduces the land and water per person; and adoption of affluent diets increases the demand for land and water per person. This study shows potentials of global food supply by linking food demand drivers with national land and water availability. Whether the available land and water is enough to meet national food demand was calculated for 187 countries. The calculations were performed for the past situation (1960 and 2010) and to assess four future scenarios (2050) to discuss different paths of diets, population numbers and agricultural expansion. Inclusion of the demand perspective in the analysis has shown stronger challenges for future global food supply than have other studies. The results show that with the "business as usual" scenario, 40% of the global population in 2050 will live in countries with not enough land nor water to meet the demands of their population. Restriction to basic diets will be the most effective in lowering both land and water constraints. Our results identify both food production and food demand factors, and the regions that may experience the strongest challenges in 2050.

  14. Quantifying Impacts of Food Trade on Water Availability Considering Water Sources

    NASA Astrophysics Data System (ADS)

    Oki, T.; Yano, S.; Hanasaki, N.

    2012-12-01

    Food production requires a lot of water, and traded food potentially has external impacts on environment through reducing the water availability in the producing region. Water footprint is supposed to be an indicator to reflect the impacts of water use. However, impacts of water use on environment, resource, and sustainability are different in place and time, and according to the sources of water withdrawals. Therefore it is preferable to characterize the water withdrawals or consumptions rather than just accumulate the total amount of water use when estimating water footprint. In this study, a new methodology, global green-water equivalent method, is proposed in which regional characterization factors are determined based on the estimates of natural hydrological cycles, such as precipitation, total runoff, and sub-surface runoff, and applied for green-water, river(+reservoir) water, and non-renewable ground water uses. Water footprint of the world associated with the production of 19 major crops was estimated using an integrated hydrological and water resources modeling system (H08), with atmospheric forcing data for 1991-2000 with spatial resolution of 0.5 by 0.5 longitudinal and latitudinal degrees. The impacts is estimated to be 6 times larger than the simple summation of green and blue water uses, and reflect the climatological water scarcity conditions geographically. The results can be used to compare the possible impacts of food trade associated with various crops from various regions on environment through reducing the availability of water resources in the cropping area.

  15. Will water scarcity in semiarid regions limit hydraulic fracturing of shale plays?

    NASA Astrophysics Data System (ADS)

    Scanlon, Bridget R.; Reedy, Robert C.; Nicot, Jean Philippe

    2014-12-01

    There is increasing concern about water constraints limiting oil and gas production using hydraulic fracturing (HF) in shale plays, particularly in semiarid regions and during droughts. Here we evaluate HF vulnerability by comparing HF water demand with supply in the semiarid Texas Eagle Ford play, the largest shale oil producer globally. Current HF water demand (18 billion gallons, bgal; 68 billion liters, bL in 2013) equates to ˜16% of total water consumption in the play area. Projected HF water demand of ˜330 bgal with ˜62 000 additional wells over the next 20 years equates to ˜10% of historic groundwater depletion from regional irrigation. Estimated potential freshwater supplies include ˜1000 bgal over 20 yr from recharge and ˜10 000 bgal from aquifer storage, with land-owner lease agreements often stipulating purchase of freshwater. However, pumpage has resulted in excessive drawdown locally with estimated declines of ˜100-200 ft in ˜6% of the western play area since HF began in 2009-2013. Non-freshwater sources include initial flowback water, which is ≤5% of HF water demand, limiting reuse/recycling. Operators report shifting to brackish groundwater with estimated groundwater storage of 80 000 bgal. Comparison with other semiarid plays indicates increasing brackish groundwater and produced water use in the Permian Basin and large surface water inputs from the Missouri River in the Bakken play. The variety of water sources in semiarid regions, with projected HF water demand representing ˜3% of fresh and ˜1% of brackish water storage in the Eagle Ford footprint indicates that, with appropriate management, water availability should not physically limit future shale energy production.

  16. Compounding Impacts of Human-Induced Water Stress and Climate Change on Water Availability.

    PubMed

    Mehran, Ali; AghaKouchak, Amir; Nakhjiri, Navid; Stewardson, Michael J; Peel, Murray C; Phillips, Thomas J; Wada, Yoshihide; Ravalico, Jakin K

    2017-07-24

    The terrestrial phase of the water cycle can be seriously impacted by water management and human water use behavior (e.g., reservoir operation, and irrigation withdrawals). Here we outline a method for assessing water availability in a changing climate, while explicitly considering anthropogenic water demand scenarios and water supply infrastructure designed to cope with climatic extremes. The framework brings a top-down and bottom-up approach to provide localized water assessment based on local water supply infrastructure and projected water demands. When our framework is applied to southeastern Australia we find that, for some combinations of climatic change and water demand, the region could experience water stress similar or worse than the epic Millennium Drought. We show considering only the influence of future climate on water supply, and neglecting future changes in water demand and water storage augmentation might lead to opposing perspectives on future water availability. While human water use can significantly exacerbate climate change impacts on water availability, if managed well, it allows societies to react and adapt to a changing climate. The methodology we present offers a unique avenue for linking climatic and hydrologic processes to water resource supply and demand management and other human interactions.

  17. Compounding Impacts of Human-Induced Water Stress and Climate Change on Water Availability

    NASA Technical Reports Server (NTRS)

    Mehran, Ali; AghaKouchak, Amir; Nakhjiri, Navid; Stewardson, Michael J.; Peel, Murray C.; Phillips, Thomas J.; Wada, Yoshihide; Ravalico, Jakin K.

    2017-01-01

    The terrestrial phase of the water cycle can be seriously impacted by water management and human water use behavior (e.g., reservoir operation, and irrigation withdrawals). Here we outline a method for assessing water availability in a changing climate, while explicitly considering anthropogenic water demand scenarios and water supply infrastructure designed to cope with climatic extremes. The framework brings a top-down and bottom-up approach to provide localized water assessment based on local water supply infrastructure and projected water demands. When our framework is applied to southeastern Australia we find that, for some combinations of climatic change and water demand, the region could experience water stress similar or worse than the epic Millennium Drought. We show considering only the influence of future climate on water supply, and neglecting future changes in water demand and water storage augmentation might lead to opposing perspectives on future water availability. While human water use can significantly exacerbate climate change impacts on water availability, if managed well, it allows societies to react and adapt to a changing climate. The methodology we present offers a unique avenue for linking climatic and hydrologic processes to water resource supply and demand management and other human interactions.

  18. Water availability limits tree productivity, carbon stocks, and carbon residence time in mature forests across the western US

    NASA Astrophysics Data System (ADS)

    Berner, Logan T.; Law, Beverly E.; Hudiburg, Tara W.

    2017-01-01

    Water availability constrains the structure and function of terrestrial ecosystems and is projected to change in many parts of the world over the coming century. We quantified the response of tree net primary productivity (NPP), live biomass (BIO), and mean carbon residence time (CRT = BIO / NPP) to spatial variation in water availability in the western US. We used forest inventory measurements from 1953 mature stands (> 100 years) in Washington, Oregon, and California (WAORCA) along with satellite and climate data sets covering the western US. We summarized forest structure and function in both domains along a 400 cm yr-1 hydrologic gradient, quantified with a climate moisture index (CMI) based on the difference between precipitation and reference evapotranspiration summed over the water year (October-September) and then averaged annually from 1985 to 2014 (CMIwy). Median NPP, BIO, and CRT computed at 10 cm yr-1 intervals along the CMIwy gradient increased monotonically with increasing CMIwy across both WAORCA (rs = 0.93-0.96, p < 0.001) and the western US (rs = 0.93-0.99, p < 0.001). Field measurements from WAORCA showed that median NPP increased from 2.2 to 5.6 Mg C ha-1 yr-1 between the driest and wettest 5 % of sites, while BIO increased from 26 to 281 Mg C ha-1 and CRT increased from 11 to 49 years. The satellite data sets revealed similar changes over the western US, though these data sets tended to plateau in the wettest areas, suggesting that additional efforts are needed to better quantify NPP and BIO from satellites in high-productivity, high-biomass forests. Our results illustrate that long-term average water availability is a key environmental constraint on tree productivity, carbon storage, and carbon residence time in mature forests across the western US, underscoring the need to assess potential ecosystem response to projected

  19. Metabolomic response of Calotropis procera growing in the desert to changes in water availability.

    PubMed

    Ramadan, Ahmed; Sabir, Jamal S M; Alakilli, Saleha Y M; Shokry, Ahmed M; Gadalla, Nour O; Edris, Sherif; Al-Kordy, Magdy A; Al-Zahrani, Hassan S; El-Domyati, Fotouh M; Bahieldin, Ahmed; Baker, Neil R; Willmitzer, Lothar; Irgang, Susann

    2014-01-01

    Water availability is a major limitation for agricultural productivity. Plants growing in severe arid climates such as deserts provide tools for studying plant growth and performance under extreme drought conditions. The perennial species Calotropis procera used in this study is a shrub growing in many arid areas which has an exceptional ability to adapt and be productive in severe arid conditions. We describe the results of studying the metabolomic response of wild C procera plants growing in the desert to a one time water supply. Leaves of C. procera plants were taken at three time points before and 1 hour, 6 hours and 12 hours after watering and subjected to a metabolomics and lipidomics analysis. Analysis of the data reveals that within one hour after watering C. procera has already responded on the metabolic level to the sudden water availability as evidenced by major changes such as increased levels of most amino acids, a decrease in sucrose, raffinose and maltitol, a decrease in storage lipids (triacylglycerols) and an increase in membrane lipids including photosynthetic membranes. These changes still prevail at the 6 hour time point after watering however 12 hours after watering the metabolomics data are essentially indistinguishable from the prewatering state thus demonstrating not only a rapid response to water availability but also a rapid response to loss of water. Taken together these data suggest that the ability of C. procera to survive under the very harsh drought conditions prevailing in the desert might be associated with its rapid adjustments to water availability and losses.

  20. Metabolomic Response of Calotropis procera Growing in the Desert to Changes in Water Availability

    PubMed Central

    Ramadan, Ahmed; Sabir, Jamal S. M.; Alakilli, Saleha Y. M.; Shokry, Ahmed M.; Gadalla, Nour O.; Edris, Sherif; Al-Kordy, Magdy A.; Al-Zahrani, Hassan S.; El-Domyati, Fotouh M.; Bahieldin, Ahmed; Baker, Neil R.; Willmitzer, Lothar; Irgang, Susann

    2014-01-01

    Water availability is a major limitation for agricultural productivity. Plants growing in severe arid climates such as deserts provide tools for studying plant growth and performance under extreme drought conditions. The perennial species Calotropis procera used in this study is a shrub growing in many arid areas which has an exceptional ability to adapt and be productive in severe arid conditions. We describe the results of studying the metabolomic response of wild C procera plants growing in the desert to a one time water supply. Leaves of C. procera plants were taken at three time points before and 1 hour, 6 hours and 12 hours after watering and subjected to a metabolomics and lipidomics analysis. Analysis of the data reveals that within one hour after watering C. procera has already responded on the metabolic level to the sudden water availability as evidenced by major changes such as increased levels of most amino acids, a decrease in sucrose, raffinose and maltitol, a decrease in storage lipids (triacylglycerols) and an increase in membrane lipids including photosynthetic membranes. These changes still prevail at the 6 hour time point after watering however 12 hours after watering the metabolomics data are essentially indistinguishable from the prewatering state thus demonstrating not only a rapid response to water availability but also a rapid response to loss of water. Taken together these data suggest that the ability of C. procera to survive under the very harsh drought conditions prevailing in the desert might be associated with its rapid adjustments to water availability and losses. PMID:24520340

  1. Contrasting precipitation seasonality influences evapotranspiration dynamics in water-limited shrublands

    NASA Astrophysics Data System (ADS)

    Villarreal, Samuel; Vargas, Rodrigo; Yepez, Enrico A.; Acosta, Jose S.; Castro, Angel; Escoto-Rodriguez, Martin; Lopez, Eulogio; Martínez-Osuna, Juan; Rodriguez, Julio C.; Smith, Stephen V.; Vivoni, Enrique R.; Watts, Christopher J.

    2016-02-01

    Water-limited ecosystems occupy nearly 30% of the Earth, but arguably, the controls on their ecosystem processes remain largely uncertain. We analyzed six site years of eddy covariance measurements of evapotranspiration (ET) from 2008 to 2010 at two water-limited shrublands: one dominated by winter precipitation (WP site) and another dominated by summer precipitation (SP site), but with similar solar radiation patterns in the Northern Hemisphere. We determined how physical forcing factors (i.e., net radiation (Rn), soil water content (SWC), air temperature (Ta), and vapor pressure deficit (VPD)) influence annual and seasonal variability of ET. Mean annual ET at SP site was 455 ± 91 mm yr-1, was mainly influenced by SWC during the dry season, by Rn during the wet season, and was highly sensitive to changes in annual precipitation (P). Mean annual ET at WP site was 363 ± 52 mm yr-1, had less interannual variability, but multiple variables (i.e., SWC, Ta, VPD, and Rn) were needed to explain ET among years and seasons. Wavelet coherence analysis showed that ET at SP site has a consistent temporal coherency with Ta and P, but this was not the case for ET at WP site. Our results support the paradigm that SWC is the main control of ET in water-limited ecosystems when radiation and temperature are not the limiting factors. In contrast, when P and SWC are decoupled from available energy (i.e., radiation and temperature), then ET is controlled by an interaction of multiple variables. Our results bring attention to the need for better understanding how climate and soil dynamics influence ET across these globally distributed ecosystems.

  2. 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.

  3. Interactions between cold and water limitation along a climate gradient produce sharp thresholds in ecosystem type, carbon balance, and water cycling

    NASA Astrophysics Data System (ADS)

    Kelly, A. E.; Goulden, M.; Fellows, A. W.

    2013-12-01

    California's Mediterranean climate supports a broad diversity of ecosystem types, including Sequoia forests in the mid-montane Sierra Nevada. Understanding how winter cold and summer drought interact to produce the lush forest in the Sierra is critical to predicting the impacts of projected climate change on California's ecosystems, water supply, and carbon cycling. We investigated how smooth gradients of temperature and water availability produced sharp thresholds in biomass, productivity, growing season, water use, and ultimately ecosystem type and function. We used the climate gradient of the western slope of the Sierra Nevada as a study system. Four eddy covariance towers were situated in the major ecosystem types of the Sierra Nevada at approximately 800-m elevation intervals. Eddy flux data were combined with remote sensing and direct measurements of biomass, productivity, soil available water, and evapotranspiration to understand how weather and available water control ecosystem production and function. We found that production at the high elevation lodgepole site at 2700 m was strongly limited by winter cold. Production at the low elevation oak woodland site at 400 m was strongly limited by summer drought. The yellow pine site at 1200 m was only 4 °C cooler than the oak woodland site, yet had an order of magnitude more biomass and productivity with year-round growth. The mixed conifer site at 2000 m is 3.5 °C warmer than the lodgepole forest, yet also has higher biomass, ten times higher productivity, and year-round growth. We conclude that there is a broad climatological 'sweet spot' within the Sierra Nevada, in which the Mediterranean climate can support large-statured forest with high growth rates. The range of the mid-elevation forest was sharply bounded by water limitation at the lower edge and cold limitation at the upper edge despite small differences in precipitation and temperature across these boundaries. Our results suggest that small changes

  4. Compounding Impacts of Human-Induced Water Stress and Climate Change on Water Availability

    DOE PAGES

    Mehran, Ali; AghaKouchak, Amir; Nakhjiri, Navid; ...

    2017-07-24

    The terrestrial phase of the water cycle can be seriously impacted by water management and human water use behavior (e.g., reservoir operation, and irrigation withdrawals). Here we outline a method for assessing water availability in a changing climate, while explicitly considering anthropogenic water demand scenarios and water supply infrastructure designed to cope with climatic extremes. The framework brings a top-down and bottom-up approach to provide localized water assessment based on local water supply infrastructure and projected water demands. When our framework is applied to southeastern Australia we find that, for some combinations of climatic change and water demand, the regionmore » could experience water stress similar or worse than the epic Millennium Drought. We show considering only the influence of future climate on water supply, and neglecting future changes in water demand and water storage augmentation might lead to opposing perspectives on future water availability. While human water use can significantly exacerbate climate change impacts on water availability, if managed well, it allows societies to react and adapt to a changing climate. The methodology we present offers a unique avenue for linking climatic and hydrologic processes to water resource supply and demand management and other human interactions.« less

  5. Compounding Impacts of Human-Induced Water Stress and Climate Change on Water Availability

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

    Mehran, Ali; AghaKouchak, Amir; Nakhjiri, Navid

    The terrestrial phase of the water cycle can be seriously impacted by water management and human water use behavior (e.g., reservoir operation, and irrigation withdrawals). Here we outline a method for assessing water availability in a changing climate, while explicitly considering anthropogenic water demand scenarios and water supply infrastructure designed to cope with climatic extremes. The framework brings a top-down and bottom-up approach to provide localized water assessment based on local water supply infrastructure and projected water demands. When our framework is applied to southeastern Australia we find that, for some combinations of climatic change and water demand, the regionmore » could experience water stress similar or worse than the epic Millennium Drought. We show considering only the influence of future climate on water supply, and neglecting future changes in water demand and water storage augmentation might lead to opposing perspectives on future water availability. While human water use can significantly exacerbate climate change impacts on water availability, if managed well, it allows societies to react and adapt to a changing climate. The methodology we present offers a unique avenue for linking climatic and hydrologic processes to water resource supply and demand management and other human interactions.« less

  6. Estimating plant available water content from remotely sensed evapotranspiration

    NASA Astrophysics Data System (ADS)

    van Dijk, A. I. J. M.; Warren, G.; Doody, T.

    2012-04-01

    Plant available water content (PAWC) is an emergent soil property that is a critical variable in hydrological modelling. PAWC determines the active soil water storage and, in water-limited environments, is the main cause of different ecohydrological behaviour between (deep-rooted) perennial vegetation and (shallow-rooted) seasonal vegetation. Conventionally, PAWC is estimated for a combination of soil and vegetation from three variables: maximum rooting depth and the volumetric water content at field capacity and permanent wilting point, respectively. Without elaborate local field observation, large uncertainties in PAWC occur due to the assumptions associated with each of the three variables. We developed an alternative, observation-based method to estimate PAWC from precipitation observations and CSIRO MODIS Reflectance-based Evapotranspiration (CMRSET) estimates. Processing steps include (1) removing residual systematic bias in the CMRSET estimates, (2) making spatially appropriate assumptions about local water inputs and surface runoff losses, (3) using mean seasonal patterns in precipitation and CMRSET to estimate the seasonal pattern in soil water storage changes, (4) from these, calculating the mean seasonal storage range, which can be treated as an estimate of PAWC. We evaluate the resulting PAWC estimates against those determined in field experiments for 180 sites across Australia. We show that the method produces better estimates of PAWC than conventional techniques. In addition, the method provides detailed information with full continental coverage at moderate resolution (250 m) scale. The resulting maps can be used to identify likely groundwater dependent ecosystems and to derive PAWC distributions for each combination of soil and vegetation type.

  7. Availability and quality of ground water, southern Ute Indian Reservation, southwestern Colorado

    USGS Publications Warehouse

    Brogden, Robert E.; Hutchinson, E. Carter; Hillier, Donald E.

    1979-01-01

    Population growth and the potential development of subsurface mineral resources have increased the need for information on the availability and quality of ground water on the Southern Ute Indian Reservation. The U.S. Geological Survey, in cooperation with the Southern Ute Tribal Council, the Four Corners Regional Planning Commission, and the U.S. Bureau of Indian Affairs, conducted a study during 1974-76 to assess the ground-water resources of the reservation. Water occurs in aquifers in the Dakota Sandstone, Mancos Shale, Mesaverde Group, Lewis Shale, Pictured Cliffs Sandstone, Fruitland Formation, Kirtland Shale, Animas and San Jose Formations, and terrace and flood-plain deposits. Well yields from sandstone and shale aquifers are small, generally in the range from 1 to 10 gallons per minute with maximum reported yields of 75 gallons per minute. Well yields from terrace deposits generally range from 5 to 10 gallons per minute with maximum yields of 50 gallons per minute. Well yields from flood-plain deposits are as much as 25 gallons per minute but average 10 gallons per minute. Water quality in aquifers depends in part on rock type. Water from sandstone, terrace, and flood-plain aquifers is predominantly a calcium bicarbonate type, whereas water from shale aquifers is predominantly a sodium bicarbonate type. Water from rocks containing interbeds of coal or carbonaceous shales may be either a calcium or sodium sulfate type. Dissolved-solids concentrations of ground water ranged from 115 to 7,130 milligrams per liter. Water from bedrock aquifers is the most mineralized, while water from terrace and flood-plain aquifers is the least mineralized. In many water samples collected from bedrock, terrace, and flood-plain aquifers, the concentrations of arsenic, chloride, dissolved solids, fluoride, iron, manganese, nitrate, selenium, and sulfate exceeded U.S. Public Health Service (1962) recommended limits for drinking water. Selenium in the ground water in excess of U

  8. Combined impacts of climate and socio-economic scenarios on irrigation water availability for a dry Mediterranean reservoir.

    PubMed

    Nunes, João Pedro; Jacinto, Rita; Keizer, Jan Jacob

    2017-04-15

    The impacts of climate and associated socio-economic changes on water availability, including supply and demand, quality, and storage volume, were evaluated for the Vale do Gaio reservoir in southern Portugal, located in a dry Mediterranean climate and already under drought stress. The SWAT model was applied with 6 scenarios for 2071-2100, involving two storylines (A1B and B1) with individual changes in climate (-9% rainfall, increasing in winter by +28 to +30%), socio-economic conditions (an increase in irrigation demand by 11%, and a replacement of cereals and pastures by sunflower), and a combination of both. Most future scenarios resulted in lower water availability, due to lower supply (-19 to -27%) combined with higher irrigation demand (+3 to +21%). This resulted in more years with limited irrigation supplies (presently: 28%; scenarios: 37 to 43%), although limitations were mitigated by lower losses to excess discharge. Land-use changes also decreased quality by increasing P concentrations (+29 to +93%). Impacts were more severe in scenario A1B than in B1, and in combined changes than in climate or socio-economic changes only. Water availability was resilient to climate change, as impacts led only to a moderate aggravation of present-day conditions. Lower future water availability could be addressed by supply and demand management strategies and, in the most extreme scenario, by water transfers from regional water reserves; water quality issues could be addressed through land-use policies. Results also highlighted the importance of taking the characteristics of water supply systems into account when designing adaptation measures for future changes. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Drought genetics have varying influence on corn water stress under differing water availability

    USDA-ARS?s Scientific Manuscript database

    Irrigated corn (Zea mays L.) in the Great Plains will be increasingly grown under limited irrigation management and greater water stress. Hybrids with drought genetics may decrease the impacts of water stress on yield. The objective of this experiment was to evaluate the effect of drought genetics o...

  10. Predicting and mapping soil available water capacity in Korea.

    PubMed

    Hong, Suk Young; Minasny, Budiman; Han, Kyung Hwa; Kim, Yihyun; Lee, Kyungdo

    2013-01-01

    The knowledge on the spatial distribution of soil available water capacity at a regional or national extent is essential, as soil water capacity is a component of the water and energy balances in the terrestrial ecosystem. It controls the evapotranspiration rate, and has a major impact on climate. This paper demonstrates a protocol for mapping soil available water capacity in South Korea at a fine scale using data available from surveys. The procedures combined digital soil mapping technology with the available soil map of 1:25,000. We used the modal profile data from the Taxonomical Classification of Korean Soils. The data consist of profile description along with physical and chemical analysis for the modal profiles of the 380 soil series. However not all soil samples have measured bulk density and water content at -10 and -1500 kPa. Thus they need to be predicted using pedotransfer functions. Furthermore, water content at -10 kPa was measured using ground samples. Thus a correction factor is derived to take into account the effect of bulk density. Results showed that Andisols has the highest mean water storage capacity, followed by Entisols and Inceptisols which have loamy texture. The lowest water retention is Entisols which are dominated by sandy materials. Profile available water capacity to a depth of 1 m was calculated and mapped for Korea. The western part of the country shows higher available water capacity than the eastern part which is mountainous and has shallower soils. The highest water storage capacity soils are the Ultisols and Alfisols (mean of 206 and 205 mm, respectively). Validation of the maps showed promising results. The map produced can be used as an indication of soil physical quality of Korean soils.

  11. Compression Limit of Two-Dimensional Water Constrained in Graphene Nanocapillaries.

    PubMed

    Zhu, YinBo; Wang, FengChao; Bai, Jaeil; Zeng, Xiao Cheng; Wu, HengAn

    2015-12-22

    Evaluation of the tensile/compression limit of a solid under conditions of tension or compression is often performed to provide mechanical properties that are critical for structure design and assessment. Algara-Siller et al. recently demonstrated that when water is constrained between two sheets of graphene, it becomes a two-dimensional (2D) liquid and then is turned into an intriguing monolayer solid with a square pattern under high lateral pressure [ Nature , 2015 , 519 , 443 - 445 ]. From a mechanics point of view, this liquid-to-solid transformation characterizes the compression limit (or metastability limit) of the 2D monolayer water. Here, we perform a simulation study of the compression limit of 2D monolayer, bilayer, and trilayer water constrained in graphene nanocapillaries. At 300 K, a myriad of 2D ice polymorphs (both crystalline-like and amorphous) are formed from the liquid water at different widths of the nanocapillaries, ranging from 6.0 to11.6 Å. For monolayer water, the compression limit is typically a few hundred MPa, while for the bilayer and trilayer water, the compression limit is 1.5 GPa or higher, reflecting the ultrahigh van der Waals pressure within the graphene nanocapillaries. The compression-limit (phase) diagram is obtained at the nanocapillary width versus pressure (h-P) plane, based on the comprehensive molecular dynamics simulations at numerous thermodynamic states as well as on the Clapeyron equation. Interestingly, the compression-limit curves exhibit multiple local minima.

  12. Water and Nitrogen Limitations of Ecosystem Processes Across Three Dryland Plant Communities

    NASA Astrophysics Data System (ADS)

    Beltz, C.; Lauenroth, W. K.; Burke, I. C.

    2017-12-01

    The availability of water and nitrogen (N) play a major role in controlling the distribution of ecosystem types and the rates of ecosystem processes across the globe. Both these resources are being altered by human activity. Anthropogenic fixation of N has increased inputs into the biosphere from 0.5 kg N ha-1 yr-1 to upwards of 10 kg N ha-1 yr-1, while the amount and seasonality of precipitation are expected to continue to change. Within dryland environments, the relationships between increasingly available N and ecosystem processes are especially complex due to dryland's characteristic strong limitation by low and highly variable precipitation. Other experiments have shown that this interplay between N and water can cause temporally complex co-limitation and spatially complex responses with variable effects on ecosystems, such as those to net primary productivity, soil respiration, and plant community composition. Research spanning multiple dryland plant communities is critical for generalizing findings to the 40% of the Earth's terrestrial surface covered in dryland ecosystems. Given IPCC projections in which both N availability and precipitation are altered, examining their interactive effect across multiple plant communities is critical to increasing our understanding of the limitations to ecosystem process in drylands. We are studying a gradient of three plant communities representing a C4 grassland (shortgrass steppe), a C3/C4 grassland (mixed grass prairie), and a shrub-dominated ecosystem with C3 and C4 grasses (sagebrush steppe). We added two levels of N (10 kg N ha-1 and 100 kg N ha-1) and increased summer monthly precipitation by 20%. Sites responded differently to treatments, with the scale of effect varying by treatment. The high-level nitrogen increased soil N availability and soil respiration, while decreasing soil carbon in the labile pool in the upper soil layers. These results will allow for better understanding of increased N in combination with

  13. Testing the limits in a greenhouse ocean: Did low nitrogen availability limit marine productivity during the end-Triassic mass extinction?

    NASA Astrophysics Data System (ADS)

    Schoepfer, Shane D.; Algeo, Thomas J.; Ward, Peter D.; Williford, Kenneth H.; Haggart, James W.

    2016-10-01

    The end-Triassic mass extinction has been characterized as a 'greenhouse extinction', related to rapid atmospheric warming and associated changes in ocean circulation and oxygenation. The response of the marine nitrogen cycle to these oceanographic changes, and the extent to which mass extinction intervals represent a deviation in nitrogen cycling from other ice-free 'greenhouse' periods of Earth history, remain poorly understood. The well-studied Kennecott Point section in Haida Gwaii, British Columbia, Canada, was deposited in the open Panthalassic Ocean, and is used here as a test case to better understand changes in the nitrogen cycle and marine productivity from the pre-crisis greenhouse of the Rhaetian to the latest-Rhaetian crisis interval. We estimated marine productivity from the late Norian to the early Hettangian using TOC- and P-based paleoproductivity transform equations, and then compared these estimates to records of sedimentary nitrogen isotopes, redox-sensitive trace elements, and biomarker data. Major negative excursions in δ15N (to ≤ 0 ‰) correspond to periods of depressed marine productivity. During these episodes, the development of a stable pycnocline below the base of the photic zone suppressed vertical mixing and limited N availability in surface waters, leading to low productivity and increased nitrogen fixation, as well as ecological stresses in the photic zone. The subsequent shoaling of euxinic waters into the ocean surface layer was fatal for most Triassic marine fauna, although the introduction of regenerated NH4+ into the photic zone may have allowed phytoplankton productivity to recover. These results indicate that the open-ocean nitrogen cycle was influenced by climatic changes during the latest Triassic, despite having existed in a greenhouse state for over 50 million years previously, and that low N availability limited marine productivity for hundreds of thousands of years during the end-Triassic crisis.

  14. When vegetation change alters ecosystem water availability

    USDA-ARS?s Scientific Manuscript database

    The combined effects of vegetation and climate change on biosphere-atmosphere water vapor (H2O) and carbon dioxide (CO2) exchanges are expected to vary depending, in part, on how biotic activity is controlled by and alters water availability. This is particularly important when a change in ecosystem...

  15. Estimating Coherence Measures from Limited Experimental Data Available

    NASA Astrophysics Data System (ADS)

    Zhang, Da-Jian; Liu, C. L.; Yu, Xiao-Dong; Tong, D. M.

    2018-04-01

    Quantifying coherence has received increasing attention, and considerable work has been directed towards finding coherence measures. While various coherence measures have been proposed in theory, an important issue following is how to estimate these coherence measures in experiments. This is a challenging task, since the state of a system is often unknown in practical applications and the accessible measurements in a real experiment are typically limited. In this Letter, we put forward an approach to estimate coherence measures of an unknown state from any limited experimental data available. Our approach is not only applicable to coherence measures but can be extended to other resource measures.

  16. Plant responses, climate pivot points, and trade-offs in water-limited ecosystems

    USGS Publications Warehouse

    Munson, Seth M.

    2013-01-01

    Plant species in dryland ecosystems are limited by water availability and may be vulnerable to increases in aridity. Methods are needed to monitor and assess the rate of change in plant abundance and composition in relation to climate, understand the potential for degradation in dryland ecosystems, and forecast future changes in plant species assemblages. I employ nearly a century of vegetation monitoring data from three North American deserts to demonstrate an approach to determine plant species responses to climate and critical points over a range of climatic conditions at which plant species shift from increases to decreases in abundance (climate pivot points). I assess these metrics from a site to regional scale and highlight how these indicators of plant performance can be modified by the physical and biotic environment. For example, shrubs were more responsive to drought and high temperatures on shallow soils with limited capacity to store water and fine-textured soils with slow percolation rates, whereas perennial grasses were more responsive to precipitation in sparse shrublands than in relatively dense grasslands and shrublands, where competition for water is likely more intense. The responses and associated climate pivot points of plant species aligned with their lifespan and structural characteristics, and the relationship between responses and climate pivot points provides evidence of the trade-off between the capacity of a plant species to increase in abundance when water is available and its drought resistance.

  17. Lower Limits of Water Use By Cotton, Maize, and Grain Sorghum in Three Great Plains Soils

    USDA-ARS?s Scientific Manuscript database

    Accurate knowledge of the amount of soil water available for crop use helps agricultural producers select cropping and irrigation management strategies that maximize crop yields. Using neutron attenuation, we measured the lower limits of soil water content (LL, in m**3 m**-3) at harvest (three seas...

  18. The paradoxical distribution of a shallow-rooted keystone species away from surface water, near the water-limited edge of its range in the Sonoran Desert: Seed-seedling conflicts

    NASA Astrophysics Data System (ADS)

    Drezner, Taly Dawn

    2013-02-01

    Species distributions reflect limiting factors, particularly near the margins of their range where density and abundance decrease as environmental factors decrease or increase to non-optimal conditions. I test whether the keystone saguaro cactus (Carnegiea gigantea), a shallow-rooted species, is indeed distributed disproportionately in areas of concentrated drainage (runnels) in a water-limited population. Carnegiea and a common nurse were sampled at a marginal site in and out of areas with concentrated surface water and chi-square analysis was used to determine the pattern of distribution. In this study I found that, surprisingly, near the hot, water-limited edge of their range, C. gigantea are found significantly less often in areas where more water would be available to them. For example, while only 20% of nurses were on interfluves, half of Carnegiea protégé were there. One possible explanation is that the subsequent redistribution of seeds by water away from preferred microsites may be important in shaping the final pattern of successful establishment. The shallow-rooted Carnegiea relies entirely on surface water for its moisture; it is thus paradoxical that the surface water so fundamentally essential to its survival throughout its life appears to hinder its establishment in precisely those sites where the greatest surface water would be available, particularly near the water-limited edge of its range.

  19. Fusion of multisource and multiscale remote sensing data for water availability assessment in a metropolitan region

    NASA Astrophysics Data System (ADS)

    Chang, N. B.; Yang, Y. J.; Daranpob, A.

    2009-09-01

    Recent extreme hydroclimatic events in the United States alone include, but are not limited to, the droughts in Maryland and the Chesapeake Bay area in 2001 through September 2002; Lake Mead in Las Vegas in 2000 through 2004; the Peace River and Lake Okeechobee in South Florida in 2006; and Lake Lanier in Atlanta, Georgia in 2007 that affected the water resources distribution in three states - Alabama, Florida and Georgia. This paper provides evidence from previous work and elaborates on the future perspectives that will collectively employ remote sensing and in-situ observations to support the implementation of the water availability assessment in a metropolitan region. Within the hydrological cycle, precipitation, soil moisture, and evapotranspiration can be monitored by using WSR-88D/NEXRAD data, RADARSAT-1 images, and GEOS images collectively to address the spatiotemporal variations of quantitative availability of waters whereas the MODIS images may be used to track down the qualitative availability of waters in terms of turbidity, Chlorophyll-a and other constitutes of concern. Tampa Bay in Florida was selected as a study site in this analysis, where the water supply infrastructure covers groundwater, desalination plant, and surface water at the same time. Research findings show that through the proper fusion of multi-source and multi-scale remote sensing data for water availability assessment in metropolitan region, a new insight of water infrastructure assessment can be gained to support sustainable planning region wide.

  20. Hydrologic modeling for monitoring water availability in Africa and the Middle East

    NASA Astrophysics Data System (ADS)

    McNally, A.; Getirana, A.; Arsenault, K. R.; Peters-Lidard, C. D.; Verdin, J. P.

    2015-12-01

    Drought impacts water resources required by crops and communities, in turn threatening lives and livelihoods. Early warning systems, which rely on inputs from hydro-climate models, are used to help manage risk and provide humanitarian assistance to the right place at the right time. However, translating advancements in hydro-climate science into action is a persistent and time-consuming challenge: scientists and decision-makers need to work together to enhance the salience, credibility, and legitimacy of the hydrological data products being produced. One organization that tackles this challenge is the Famine Early Warning Systems Network (FEWS NET), which has been using evidence-based approaches to address food security since the 1980s.In this presentation, we describe the FEWS NET Land Data Assimilation System (FLDAS), developed by FEWS NET and NASA hydrologic scientists to maximize the use of limited hydro-climatic observations for humanitarian applications. The FLDAS, an instance of the NASA Land Information System (LIS), is comprised of land surface models driven by satellite rainfall inputs already familiar to FEWS NET food security analysts. First, we evaluate the quality of model outputs over parts of the Middle East and Africa using remotely sensed soil moisture and vegetation indices. We then describe derived water availability indices that have been identified by analysts as potentially useful sources of information. Specifically, we demonstrate how the Baseline Water Stress and Drought Severity Index detect recent water availability crisis events in the Tigris-Euphrates Basin and the Gaborone Reservoir, Botswana. Finally we discuss ongoing work to deliver this information to FEWS NET analysts in a timely and user-friendly manner, with the ultimate goal of integrating these water availability metrics into regular decision-making activities.

  1. Limited irrigation research and infrared thermometry for detecting water stress

    USDA-ARS?s Scientific Manuscript database

    The USDA-ARS Limited Irrigation Research Farm, located outside of Greeley Colorado, is an experiment evaluating management perspectives of limited irrigation water. An overview of the farm systems is shown, including drip irrigation systems, water budgeting, and experimental design, as well as preli...

  2. Water Availability for the Western United States - Key Scientific Challenges

    USGS Publications Warehouse

    Anderson, Mark Theodore; Woosley, Lloyd H.

    2005-01-01

    In the Western United States, the availability of water has become a serious concern for many communities and rural areas. Near population centers, surface-water supplies are fully appropriated, and many communities are dependent upon ground water drawn from storage, which is an unsustainable strategy. Water of acceptable quality is increasingly hard to find because local sources are allocated to prior uses, depleted by overpumping, or diminished by drought stress. Some of the inherent characteristics of the West add complexity to the task of securing water supplies. The Western States, including the arid Southwest, have the most rapid population growth in the United States. The climate varies widely in the West, but it is best known for its low precipitation, aridity, and drought. There is evidence that the climate is warming, which will have consequences for Western water supplies, such as increased minimum streamflow and earlier snowmelt events in snow-dominated basins. The potential for departures from average climatic conditions threatens to disrupt society and local to regional economies. The appropriative rights doctrine governs the management of water in most Western States, although some aspects of the riparian doctrine are being incorporated. The 'use it or lose it' provisions of Western water law discourage conservation and make the reallocation of water to instream environmental uses more difficult. The hydrologic sciences have defined the interconnectedness of ground water and surface water, yet these resources are still administered separately by most States. The definition of water availability has been expanded to include sustaining riparian ecosystems and individual endangered species, which are disproportionately represented in the Western States. Federal reserved rights, common in the West because of the large amount of Federal land, exist with quite senior priority dates whether or not water is currently being used. A major challenge for water

  3. Drought response of five conifer species under contrasting water availability suggests high vulnerability of Norway spruce and European larch.

    PubMed

    Lévesque, Mathieu; Saurer, Matthias; Siegwolf, Rolf; Eilmann, Britta; Brang, Peter; Bugmann, Harald; Rigling, Andreas

    2013-10-01

    The ability of tree species to cope with anticipated decrease in water availability is still poorly understood. We evaluated the potential of Norway spruce, Scots pine, European larch, black pine, and Douglas-fir to withstand drought in a drier future climate by analyzing their past growth and physiological responses at a xeric and a mesic site in Central Europe using dendroecological methods. Earlywood, latewood, and total ring width, as well as the δ(13) C and δ(18) O in early- and latewood were measured and statistically related to a multiscalar soil water deficit index from 1961 to 2009. At the xeric site, δ(13) C values of all species were strongly linked to water deficits that lasted longer than 11 months, indicating a long-term cumulative effect on the carbon pool. Trees at the xeric site were particularly sensitive to soil water recharge in the preceding autumn and early spring. The native species European larch and Norway spruce, growing close to their dry distribution limit at the xeric site, were found to be the most vulnerable species to soil water deficits. At the mesic site, summer water availability was critical for all species, whereas water availability prior to the growing season was less important. Trees at the mesic were more vulnerable to water deficits of shorter duration than the xeric site. We conclude that if summers become drier, trees growing on mesic sites will undergo significant growth reductions, whereas at their dry distribution limit in the Alps, tree growth of the highly sensitive spruce and larch may collapse, likely inducing dieback and compromising the provision of ecosystem services. However, the magnitude of these changes will be mediated strongly by soil water recharge in winter and thus water availability at the beginning of the growing season. © 2013 John Wiley & Sons Ltd.

  4. Bacterial invasion potential in water is determined by nutrient availability and the indigenous community.

    PubMed

    Van Nevel, Sam; De Roy, Karen; Boon, Nico

    2013-09-01

    In drinking water (DW) and the distribution systems, bacterial growth and biofilm formation have to be controlled both for limiting taste or odour development and preventing clogging or biocorrosion problems. After a contamination with undesired bacteria, factors like nutrient availability and temperature will influence the survival of these invaders. Understanding the conditions enabling invaders to proliferate is essential for a holistic approach towards microbial risk assessment in DW. Pseudomonas putida was used as a model invader because this easy-growing bacterium can use a wide range of substrates. Invasion experiments in oligo- to eutrophic waters showed the requirement of both a carbon and phosphate source for survival of P. putida in DW. Addition of C, N and P enabled P. putida to grow in DW from 5.80 × 10(4) to 1.84 × 10(8) cells mL(-1) and survive for at least 12 days. However, in surface water with similar nutrient concentrations, P. putida did not survive, indicating the concomitant importance of the present indigenous microbial community of the specific water sample. Either extensive carbon or phosphate limitation can be used in water treatment design in order to obtain a DW which is not susceptible for unwanted bacterial growth. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. Availability of limited service food outlets surrounding schools in British Columbia.

    PubMed

    Black, Jennifer L; Day, Meghan

    2012-06-05

    The purpose of this study was to provide a descriptive profile of the availability of limited service food outlets surrounding public schools in British Columbia, Canada. Data from the 2010 Canadian Business Data Files were used to identify limited service food outlets including fast food outlets, beverage and snack food stores, delis and convenience stores. The number of food outlets within 800 metres of 1,392 public schools and the distance from schools to the nearest food outlets were assessed. Multivariate regression models examined the associations between food outlet availability and school-level characteristics. In 2010, over half of the public schools in BC (54%) were located within a 10-12 minute walk from at least one limited service food outlet. The median closest distance to a food outlet was just over 1 km (1016 m). Schools comprised of students living in densely populated urban neighbourhoods and neighbourhoods characterized by lower socio-economic status were more likely to have access to limited service food outlets within walking distance. After adjusting for school-level median family income and population density, larger schools had higher odds of exposure to food vendors compared to schools with fewer students. The availability of and proximity to limited service food outlets vary widely across schools in British Columbia and school-level characteristics are significantly associated with food outlet availability. Additional research is needed to understand how food environment exposures inside and surrounding schools impact students' attitudes, food choices and dietary quality.

  6. Uncertainties in Past and Future Global Water Availability

    NASA Astrophysics Data System (ADS)

    Sheffield, J.; Kam, J.

    2014-12-01

    Understanding how water availability changes on inter-annual to decadal time scales and how it may change in the future under climate change are a key part of understanding future stresses on water and food security. Historic evaluations of water availability on regional to global scales are generally based on large-scale model simulations with their associated uncertainties, in particular for long-term changes. Uncertainties are due to model errors and missing processes, parameter uncertainty, and errors in meteorological forcing data. Recent multi-model inter-comparisons and impact studies have highlighted large differences for past reconstructions, due to different simplifying assumptions in the models or the inclusion of physical processes such as CO2 fertilization. Modeling of direct anthropogenic factors such as water and land management also carry large uncertainties in their physical representation and from lack of socio-economic data. Furthermore, there is little understanding of the impact of uncertainties in the meteorological forcings that underpin these historic simulations. Similarly, future changes in water availability are highly uncertain due to climate model diversity, natural variability and scenario uncertainty, each of which dominates at different time scales. In particular, natural climate variability is expected to dominate any externally forced signal over the next several decades. We present results from multi-land surface model simulations of the historic global availability of water in the context of natural variability (droughts) and long-term changes (drying). The simulations take into account the impact of uncertainties in the meteorological forcings and the incorporation of water management in the form of reservoirs and irrigation. The results indicate that model uncertainty is important for short-term drought events, and forcing uncertainty is particularly important for long-term changes, especially uncertainty in precipitation due

  7. Efficiency limits for photoelectrochemical water-splitting

    DOE PAGES

    Fountaine, Katherine T.; Lewerenz, Hans Joachim; Atwater, Harry A.

    2016-12-02

    Theoretical limiting efficiencies have a critical role in determining technological viability and expectations for device prototypes, as evidenced by the photovoltaics community’s focus on detailed balance. However, due to their multicomponent nature, photoelectrochemical devices do not have an equivalent analogue to detailed balance, and reported theoretical efficiency limits vary depending on the assumptions made. Here we introduce a unified framework for photoelectrochemical device performance through which all previous limiting efficiencies can be understood and contextualized. Ideal and experimentally realistic limiting efficiencies are presented, and then generalized using five representative parameters—semiconductor absorption fraction, external radiative efficiency, series resistance, shunt resistance andmore » catalytic exchange current density—to account for imperfect light absorption, charge transport and catalysis. Finally, we discuss the origin of deviations between the limits discussed herein and reported water-splitting efficiencies. This analysis provides insight into the primary factors that determine device performance and a powerful handle to improve device efficiency.« less

  8. Limited Irrigation Water Management Research in Colorado, USA

    USDA-ARS?s Scientific Manuscript database

    The Limited Irrigation Research Farm (LIRF) is located in north-central Colorado (USA) near the city of Greeley. The research focus is to explore management objectives focused on maintaining high crop yields with limited water supplies. Researchers, which include agricultural engineers and plant phy...

  9. Habitat, not resource availability, limits consumer production in lake ecosystems

    USGS Publications Warehouse

    Craig, Nicola; Jones, Stuart E.; Weidel, Brian C.; Solomon, Christopher T.

    2015-01-01

    Food web productivity in lakes can be limited by dissolved organic carbon (DOC), which reduces fish production by limiting the abundance of their zoobenthic prey. We demonstrate that in a set of 10 small, north temperate lakes spanning a wide DOC gradient, these negative effects of high DOC concentrations on zoobenthos production are driven primarily by availability of warm, well-oxygenated habitat, rather than by light limitation of benthic primary production as previously proposed. There was no significant effect of benthic primary production on zoobenthos production after controlling for oxygen, even though stable isotope analysis indicated that zoobenthos do use this resource. Mean whole-lake zoobenthos production was lower in high-DOC lakes with reduced availability of oxygenated habitat, as was fish biomass. These insights improve understanding of lake food webs and inform management in the face of spatial variability and ongoing temporal change in lake DOC concentrations.

  10. Excess growing-season water limits lowland black spruce productivity

    NASA Astrophysics Data System (ADS)

    Dymond, S.; Kolka, R. K.; Bolstad, P. V.; Gill, K.; Curzon, M.; D'Amato, A. W.

    2015-12-01

    The annual growth of many tree species is limited by water availability, with growth increasing as water becomes less scarce. In lowland bogs of northern Minnesota, however, black spruce (Picea mariana) is often exposed to excess water via high water table elevations. These trees grow in thick deposits of organic mucky peat and often have shallow rooting systems to avoid the complete submersion of roots in water. While it is generally believed that black spruce decrease growth rates with rising water table elevations, this hypothesis has not been tested in situ. We used a unique, 50-year record of daily bog water table elevations at the Marcell Experimental Forest (MEF) in northern Minnesota to investigate the relationship between climate and black spruce productivity. Nine 1/20th ha circular plots were established in five different bogs and tree height, diameter-at-breast-height (DBH), and crown class were recorded. Additionally, two perpendicular cores were collected on all trees greater than 10 cm diameter-at-breast-height. Tree cores were sanded, mounted, cross-dated, and de-trended according to standard dendrochronological procedures. Ring width measurements were correlated with precipitation, temperature, and water table elevation using package BootRes in R to determine the climatic variables most associated with stand level productivity. Across the different plots, we found that early growing season water table elevation (May and June) was negatively correlated with both individual and stand-level black spruce growth (p < 0.01), while growth was positively correlated with March temperatures (p < 0.01). No significant relationships existed between black spruce growth and monthly precipitation. If summer water table elevations in these peatland ecosystems rise as is anticipated with more extreme precipitation events due to climate change, we could see an overall decrease in the stand level productivity of black spruce.

  11. Water availability and trachoma.

    PubMed

    West, S; Lynch, M; Turner, V; Munoz, B; Rapoza, P; Mmbaga, B B; Taylor, H R

    1989-01-01

    As part of an epidemiological survey of risk factors for trachoma in 20 villages in the United Republic of Tanzania, we investigated the relationship of village water pumps, distance to water source, and quantity of household water to the risk of inflammatory trachoma. We also evaluated whether there was an association between the cleanliness of children's faces and these water variables. No association was found between the presence of a village water supply and the prevalence of trachoma. However, the risk of trachoma in the household increased with the distance to a water source--although there was no association with the estimated daily amount of water brought into the house. Likewise, children were more likely to have unclean faces if they lived more than 30 minutes from a water source, but whether they had clean faces was not associated with the daily quantity of water brought into the household. The effect of the distance to water supply on trachoma may well reflect the value placed on water within the family, and this determines the priority for its use for hygiene purposes. The results of the study suggest that changing the access to water per se may be insufficient to alter the prevalence of trachoma without also a concomitant effort to change the perception of how water should be utilized in the home.

  12. Ballast water regulations and the move toward concentration-based numeric discharge limits.

    PubMed

    Albert, Ryan J; Lishman, John M; Saxena, Juhi R

    2013-03-01

    Ballast water from shipping is a principal source for the introduction of nonindigenous species. As a result, numerous government bodies have adopted various ballast water management practices and discharge standards to slow or eliminate the future introduction and dispersal of these nonindigenous species. For researchers studying ballast water issues, understanding the regulatory framework is helpful to define the scope of research needed by policy makers to develop effective regulations. However, for most scientists, this information is difficult to obtain because it is outside the standard scientific literature and often difficult to interpret. This paper provides a brief review of the regulatory framework directed toward scientists studying ballast water and aquatic invasive species issues. We describe different approaches to ballast water management in international, U.S. federal and state, and domestic ballast water regulation. Specifically, we discuss standards established by the International Maritime Organization (IMO), the U.S. Coast Guard and U.S. Environmental Protection Agency, and individual states in the United States including California, New York, and Minnesota. Additionally, outside the United States, countries such as Australia, Canada, and New Zealand have well-established domestic ballast water regulatory regimes. Different approaches to regulation have recently resulted in variations between numeric concentration-based ballast water discharge limits, particularly in the United States, as well as reliance on use of ballast water exchange pending development and adoption of rigorous science-based discharge standards. To date, numeric concentration-based discharge limits have not generally been based upon a thorough application of risk-assessment methodologies. Regulators, making decisions based on the available information and methodologies before them, have consequently established varying standards, or not established standards at all. The

  13. Soil Microbial Properties and Plant Growth Responses to Carbon and Water Addition in a Temperate Steppe: The Importance of Nutrient Availability

    PubMed Central

    Guo, Chengyuan; Wang, Renzhong; Xiao, Chunwang

    2012-01-01

    Background Global climatic change is generally expected to stimulate net primary production, and consequently increase soil carbon (C) input. The enhanced C input together with potentially increased precipitation may affect soil microbial processes and plant growth. Methodology/Principal Findings To examine the effects of C and water additions on soil microbial properties and plant growth, we conducted an experiment lasting two years in a temperate steppe of northeastern China. We found that soil C and water additions significantly affected microbial properties and stimulated plant growth. Carbon addition significantly increased soil microbial biomass and activity but had a limited effect on microbial community structure. Water addition significantly increased soil microbial activity in the first year but the response to water decreased in the second year. The water-induced changes of microbial activity could be ascribed to decreased soil nitrogen (N) availability and to the shift in soil microbial community structure. However, no water effect on soil microbial activity was visible under C addition during the two years, likely because C addition alleviated nutrient limitation of soil microbes. In addition, C and water additions interacted to affect plant functional group composition. Water addition significantly increased the ratio of grass to forb biomass in C addition plots but showed only minor effects under ambient C levels. Our results suggest that soil microbial activity and plant growth are limited by nutrient (C and N) and water availability, and highlight the importance of nutrient availability in modulating the responses of soil microbes and plants to potentially increased precipitation in the temperate steppe. Conclusions/Significance Increased soil C input and precipitation would show significant effects on soil microbial properties and plant growth in the temperate steppe. These findings will improve our understanding of the responses of soil microbes

  14. Improvement of water and light availability after thinning at a xeric site: which matters more? A dual isotope approach.

    PubMed

    Giuggiola, Arnaud; Ogée, Jérôme; Rigling, Andreas; Gessler, Arthur; Bugmann, Harald; Treydte, Kerstin

    2016-04-01

    Thinning fosters individual tree growth by increasing the availability of water, light and nutrients. At sites where water rather than light is limiting, thinning also enhances soil evaporation and might not be beneficial. Detailed knowledge of the short- to long-term physiological response underlying the growth responses to thinning is crucial for the management of forests already suffering from recurrent drought-induced dieback. We applied a dual isotope approach together with mechanistic isotope models to study the physiological processes underlying long-term growth enhancement of heavily thinned Pinus sylvestris in a xeric forest in Switzerland. This approach allowed us to identify and disentangle thinning-induced changes in stomatal conductance and assimilation rate. At our xeric study site, the increase in stomatal conductance far outweighed the increase in assimilation, implying that growth release in heavily thinned trees is primarily driven by enhanced water availability rather than increased light availability. We conclude that in forests with relatively isohydric species (drought avoiders) that are growing close to their physiological limits, thinning is recommended to maintain a less negative water balance and thus foster tree growth, and ultimately the survival of forest trees under drought. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  15. Climate change and water availability for vulnerable agriculture

    NASA Astrophysics Data System (ADS)

    Dalezios, Nicolas; Tarquis, Ana Maria

    2017-04-01

    Climatic projections for the Mediterranean basin indicate that the area will suffer a decrease in water resources due to climate change. The key climatic trends identified for the Mediterranean region are continuous temperature increase, further drying with precipitation decrease and the accentuation of climate extremes, such as droughts, heat waves and/or forest fires, which are expected to have a profound effect on agriculture. Indeed, the impact of climate variability on agricultural production is important at local, regional, national, as well as global scales. Agriculture of any kind is strongly influenced by the availability of water. Climate change will modify rainfall, evaporation, runoff, and soil moisture storage patterns. Changes in total seasonal precipitation or in its pattern of variability are both important. Similarly, with higher temperatures, the water-holding capacity of the atmosphere and evaporation into the atmosphere increase, and this favors increased climate variability, with more intense precipitation and more droughts. As a result, crop yields are affected by variations in climatic factors, such as air temperature and precipitation, and the frequency and severity of the above mentioned extreme events. The aim of this work is to briefly present the main effects of climate change and variability on water resources with respect to water availability for vulnerable agriculture, namely in the Mediterranean region. Results of undertaken studies in Greece on precipitation patterns and drought assessment using historical data records are presented. Based on precipitation frequency analysis, evidence of precipitation reductions is shown. Drought is assessed through an agricultural drought index, namely the Vegetation Health Index (VHI), in Thessaly, a drought-prone region in central Greece. The results justify the importance of water availability for vulnerable agriculture and the need for drought monitoring in the Mediterranean basin as part of

  16. Interactions between plant nutrients, water and carbon dioxide as factors limiting crop yields

    PubMed Central

    Gregory, P. J.; Simmonds, L. P.; Warren, G. P.

    1997-01-01

    Biomass production of annual crops is often directly proportional to the amounts of radiation intercepted, water transpired and nutrients taken up. In many places the amount of rainfall during the period of rapid crop growth is less than the potential rate of evaporation, so that depletion of stored soil water is commonplace. The rate of mineralization of nitrogen (N) from organic matter and the processes of nutrient loss are closely related to the availability of soil water. Results from Kenya indicate the rapid changes in nitrate availability following rain.
    Nutrient supply has a large effect on the quantity of radiation intercepted and hence, biomass production. There is considerable scope for encouraging canopy expansion to conserve water by reducing evaporation from the soil surface in environments where it is frequently rewetted, and where the unsaturated hydraulic conductivity of the soil is sufficient to supply water at the energy limited rate (e.g. northern Syria). In regions with high evaporative demand and coarse-textured soils (e.g. Niger), transpiration may be increased by management techniques that reduce drainage.
    Increases in atmospheric [CO2] are likely to have only a small impact on crop yields when allowance is made for the interacting effects of temperature, and water and nutrient supply.

  17. WATER INFORMATION AVAILABLE FROM THE U. S. GEOLOGICAL SURVEY.

    USGS Publications Warehouse

    Showen, Charles R.

    1985-01-01

    As a part of the Geological Survey's program of releasing water data to the public, two large-scale computerized systems are maintained. The National Water Data Storage and Retrieval System was developed to provide more effective and efficient management of data-releasing activities and provides for the processing, storage, and retrieval of surface-water, ground-water and water-quality data. Another service available is providing assistance to users of water data to identify, locate, and acquire needed data. This service is provided by the National Water Data Exchange, which has the mission to identify sources of water data and to provide the connection between those who acquire and those who use water data.

  18. Evaluating options for balancing the water-electricity nexus in California: part 1--securing water availability.

    PubMed

    Tarroja, Brian; AghaKouchak, Amir; Sobhani, Reza; Feldman, David; Jiang, Sunny; Samuelsen, Scott

    2014-11-01

    The technical potential and effectiveness of different water supply options for securing water availability in a large-scale, interconnected water supply system under historical and climate-change augmented inflow and demand conditions were compared. Part 1 of the study focused on determining the scale of the options required to secure water availability and compared the effectiveness of different options. A spatially and temporally resolved model of California's major surface reservoirs was developed, and its sensitivity to urban water conservation, desalination, and water reuse was examined. Potential capacities of the different options were determined. Under historical (baseline) hydrology conditions, many individual options were found to be capable of securing water availability alone. Under climate change augment conditions, a portfolio approach was necessary. The water savings from many individual options other than desalination were insufficient in the latter, however, relying on seawater desalination alone requires extreme capacity installations which have energy, brine disposal, management, and cost implications. The importance of identifying and utilizing points of leverage in the system for choosing where to deploy different options is also demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. The Influence of Climate Change on Irrigated Water Demands and Surface Water Availability of the Yellow River Basin

    NASA Astrophysics Data System (ADS)

    Troy, T. J.; Zhang, J.

    2017-12-01

    Balancing irrigated water demands and surface water availability is critical for sustainable water resources management. In China, irrigation is the largest water user, and there is concern that irrigated water demands will be affected by climate change. If the relationship between climate change, irrigated water demands and surface water availability is quantified, then effective measures can be developed to maintain food production while ensuring water sustainability. This research focuses on the Yellow River, the second longest in China, and analyzes the impact of historical and projected climate change on agricultural water demands and surface water availability. Corn and wheat are selected as representative crops to estimate the effect of temperature and precipitin changes on irrigated water demands. The VIC model is used to simulate daily streamflow throughout the Yellow River, providing estimates of surface water availability. Overall, results indicate the irrigated water need and surface water availability are impacted by climate change, with spatially varying impacts depending on spatial patterns of climate trends and river network position. This research provides insight into water security in the Yellow River basin, indicating where water efficiency measures are needed and where they are not.

  20. Assessing climate change impacts on water availability of snowmelt-dominated basins of the Upper Rio Grande Basin

    USDA-ARS?s Scientific Manuscript database

    Study Region- Upper Rio Grande, Colorado and New Mexico, USA: Climate change is predicted to further limit the water availability of the arid southwestern U.S. In this study, the Snowmelt Runoff Model is used to evaluate impacts of increased temperature and altered precipitation on snow covered are...

  1. Potential Water Availability Index (PWAI): A New Water Vulnerability Index for Africa Based on GRACE Data

    NASA Astrophysics Data System (ADS)

    Hasan, E.; Tarhule, A.; Hong, Y.; Moore, B., III

    2016-12-01

    The critical role of water in enabling or constraining human wellbeing and socio-economic activities has led to interest in quantitatively establishing the status or index of water (in)sufficiency over time and space. Introduced in 1989, the first widely accepted index expressed the status of water resources availability in terms of vulnerability, stress, or scarcity. Since then, numerous refinements and modifications to the concept have been published but nearly all adopt the same basic formulation; water status is a function of available water resources and demand or use. However, accurately defining and assessing `available water' has proved problematic especially in data scarce regions, such as Africa. In this paper, we use Total Water Storage (TWS) estimated from NASA's Gravity Recovery and Climate Experiment (GRACE) in lieu of observational hydrologic data, to estimate the Water Scarcity Index (WSI) for Africa at country level. The monthly TWS Positive anomalies represent periods of net system recharge while negative anomalies represent net system loss due to evapotranspiration and anthropogenic withdrawals. The procedure is as follows. First, we calculated the long-term (2002-2014) Internal Water Storage (IWS) for each country using the monthly precipitation data from the Global Precipitation Climatology Centre (GPCC). Next, the yearly cumulative positive and negative anomalies were added to the long-term IWS to obtain volumetric Potential Water Storage (VPWS) per country. By dividing VPWS by population, we obtain estimates of per capita water availability which can be grouped into vulnerability classes using established thresholds. Our VPWS showed very high correlation (R2 =0.94, p=0.0001) with the values of Internal Renewable Water Resources (IRWR) estimated by AQUSTAT. Additionally, the GWSI is highly correlated (R2 =0.94, p=0.0001) with the existing WSI index from the world bank data center. The novelty and contribution of our approach is in using GRACE

  2. Determining the impacts of climate change and catchment development on future water availability in Tasmania, Australia

    NASA Astrophysics Data System (ADS)

    Post, David

    2010-05-01

    In a water-scarce country such as Australia, detailed, accurate and reliable assessments of current and future water availability are essential in order to adequately manage the limited water resource. This presentation describes a recently completed study which provided an assessment of current water availability in Tasmania, Australia, and also determined how this water availability would be impacted by climate change and proposed catchment development by the year 2030. The Tasmania Sustainable Yields Project (http://www.csiro.au/partnerships/TasSY.html) assessed current water availability through the application of rainfall-runoff models, river models, and recharge and groundwater models. These were calibrated to streamflow records and parameterised using estimates of current groundwater and surface water extractions and use. Having derived a credible estimate of current water availability, the impacts of future climate change on water availability were determined through deriving changes in rainfall and potential evapotranspiration from 15 IPCC AR4 global climate models. These changes in rainfall were then dynamically downscaled using the CSIRO-CCAM model over the relatively small study area (50,000 square km). A future climate sequence was derived by modifying the historical 84-year climate sequence based on these changes in rainfall and potential evapotranspiration. This future climate sequence was then run through the rainfall-runoff, river, recharge and groundwater models to give an estimate of water availability under future climate. To estimate the impacts of future catchment development on water availability, the models were modified and re-run to reflect projected increases in development. Specifically, outputs from the rainfall-runoff and recharge models were reduced over areas of projected future plantation forestry. Conversely, groundwater recharge was increased over areas of new irrigated agriculture and new extractions of water for irrigation were

  3. Progress toward establishing a national assessment of water availability and use

    USGS Publications Warehouse

    Alley, William M.; Evenson, Eric J.; Barber, Nancy L.; Bruce, Breton W.; Dennehy, Kevin F.; Freeman, Mary C.; Freeman, Ward O.; Fischer, Jeffrey M.; Hughes, William B.; Kennen, Jonathan G.; Kiang, Julie E.; Maloney, Kelly O.; Musgrove, MaryLynn; Ralston, Barbara E.; Tessler, Steven; Verdin, James P.

    2013-01-01

    The Omnibus Public Land Management Act of 2009 (Public Law 111-11) was passed into law on March 30, 2009. Subtitle F, also known as the SECURE Water Act, calls for the establishment of a "national water availability and use assessment program" within the U.S. Geological Survey (USGS). A major driver for this recommendation was that national water availability and use have not been comprehensively assessed since 1978. This report fulfills a requirement to report to Congress on progress in implementing the national water availability and use assessment program, also referred to as the National Water Census. The SECURE Water Act authorized \\$20 million for each of fiscal years (FY) 2009 through 2023 for assessment of national water availability and use. The first appropriation for this effort was \\$4 million in FY 2011, followed by an appropriation of \\$6 million in FY 2012. The National Water Census synthesizes and reports information at the regional and national scales, with an emphasis on compiling and reporting the information in a way that is useful to states and others responsible for water management and natural-resource issues. The USGS works with Federal and non-Federal agencies, universities, and other organizations to ensure that the information can be aggregated with other types of water-availability and socioeconomic information, such as data on food and energy production. To maximize the utility of the information, the USGS coordinates the design and development of the effort through the Federal Advisory Committee on Water Information. A National Water Census is a complex undertaking, particularly because there are major gaps in the information needed to conduct such an assessment. To maximize progress, the USGS engaged stakeholders in a discussion of priorities and leveraged existing studies and program activities to enhance efforts toward the development of a National Water Census.

  4. Mapping water availability, projected use and cost in the western United States

    NASA Astrophysics Data System (ADS)

    Tidwell, Vincent C.; Moreland, Barbara D.; Zemlick, Katie M.; Roberts, Barry L.; Passell, Howard D.; Jensen, Daniel; Forsgren, Christopher; Sehlke, Gerald; Cook, Margaret A.; King, Carey W.; Larsen, Sara

    2014-05-01

    New demands for water can be satisfied through a variety of source options. In some basins surface and/or groundwater may be available through permitting with the state water management agency (termed unappropriated water), alternatively water might be purchased and transferred out of its current use to another (termed appropriated water), or non-traditional water sources can be captured and treated (e.g., wastewater). The relative availability and cost of each source are key factors in the development decision. Unfortunately, these measures are location dependent with no consistent or comparable set of data available for evaluating competing water sources. With the help of western water managers, water availability was mapped for over 1200 watersheds throughout the western US. Five water sources were individually examined, including unappropriated surface water, unappropriated groundwater, appropriated water, municipal wastewater and brackish groundwater. Also mapped was projected change in consumptive water use from 2010 to 2030. Associated costs to acquire, convey and treat the water, as necessary, for each of the five sources were estimated. These metrics were developed to support regional water planning and policy analysis with initial application to electric transmission planning in the western US.

  5. Reduction of Turbidity of Water Using Locally Available Natural Coagulants

    PubMed Central

    Asrafuzzaman, Md.; Fakhruddin, A. N. M.; Hossain, Md. Alamgir

    2011-01-01

    Turbidity imparts a great problem in water treatment. Moringa oleifera, Cicer arietinum, and Dolichos lablab were used as locally available natural coagulants in this study to reduce turbidity of synthetic water. The tests were carried out, using artificial turbid water with conventional jar test apparatus. Optimum mixing intensity and duration were determined. After dosing water-soluble extracts of Moringa oleifera, Cicer arietinum, and Dolichos lablab reduced turbidity to 5.9, 3.9, and 11.1 nephelometric turbidity unit (NTU), respectively, from 100 NTU and 5, 3.3, and 9.5, NTU, respectively, after dosing and filtration. Natural coagulants worked better with high, turbid, water compare to medium, or low, turbid, water. Highest turbidity reduction efficiency (95.89%) was found with Cicer arietinum. About 89 to 96% total coliform reduction were also found with natural coagulant treatment of turbid water. Using locally available natural coagulants, suitable, easier, and environment friendly options for water treatment were observed. PMID:23724307

  6. Multilayer geospatial analysis of water availability for shale resources development in Mexico

    NASA Astrophysics Data System (ADS)

    Galdeano, C.; Cook, M. A.; Webber, M. E.

    2017-08-01

    Mexico’s government enacted an energy reform in 2013 that aims to foster competitiveness and private investment throughout the energy sector value chain. As part of this reform, it is expected that extraction of oil and gas via hydraulic fracturing will increase in five shale basins (e.g. Burgos, Sabinas, Tampico, Tuxpan, and Veracruz). Because hydraulic fracturing is a water-intensive activity, it is relevant to assess the potential water availability for this activity in Mexico. This research aims to quantify the water availability for hydraulic fracturing in Mexico and identify its spatial distribution along the five shale basins. The methodology consisted of a multilayer geospatial analysis that overlays the water availability in the watersheds and aquifers with the different types of shale resources areas (e.g. oil and associated gas, wet gas and condensate, and dry gas) in the five shale basins. The aquifers and watersheds in Mexico are classified in four zones depending on average annual water availability. Three scenarios were examined based on different impact level on watersheds and aquifers from hydraulic fracturing. For the most conservative scenario analyzed, the results showed that the water available could be used to extract between 8.15 and 70.42 Quadrillion British thermal units (Quads) of energy in the typical 20-30 year lifetime of the hydraulic fracturing wells that could be supplied with the annual water availability overlaying the shale areas, with an average across estimates of around 18.05 Quads. However, geographic variation in water availability could represent a challenge for extracting the shale reserves. Most of the water available is located closer to the Gulf of Mexico, but the areas with the larger recoverable shale reserves coincide with less water availability in Northern Mexico. New water management techniques (such as recycling and re-use), more efficient fracturing methods, shifts in usage patterns, or other water sources need

  7. Effects of trampling on morphological and mechanical traits of dryland shrub species do not depend on water availability.

    PubMed

    Xu, Liang; Freitas, Sofia M A; Yu, Fei-Hai; Dong, Ming; Anten, Niels P R; Werger, Marinus J A

    2013-01-01

    In semiarid drylands water shortage and trampling by large herbivores are two factors limiting plant growth and distribution. Trampling can strongly affect plant performance, but little is known about responses of morphological and mechanical traits of woody plants to trampling and their possible interaction with water availability. Seedlings of four shrubs (Caragana intermedia, Cynanchum komarovi, Hedysarum laeve and Hippophae rhamnoides) common in the semiarid Mu Us Sandland were grown at 4% and 10% soil water content and exposed to either simulated trampling or not. Growth, morphological and mechanical traits were measured. Trampling decreased vertical height and increased basal diameter and stem resistance to bending and rupture (as indicated by the increased minimum bend and break force) in all species. Increasing water availability increased biomass, stem length, basal diameter, leaf thickness and rigidity of stems in all species except C. komarovii. However, there were no interactive effects of trampling and water content on any of these traits among species except for minimum bend force and the ratio between stem resistance to rupture and bending. Overall shrub species have a high degree of trampling resistance by morphological and mechanical modifications, and the effects of trampling do not depend on water availability. However, the increasing water availability can also affect trade-off between stem strength and flexibility caused by trampling, which differs among species. Water plays an important role not only in growth but also in trampling adaptation in drylands.

  8. Physiological strategies of co-occurring oaks in a water- and nutrient-limited ecosystem

    Treesearch

    Heidi Renninger; Nicholas Carlo; Kenneth L. Clark; Karina V.R. Schafer

    2014-01-01

    Oak species are well suited to water-limited conditions by either avoiding water stress through deep rooting or tolerating water stress through tight stomatal control. In co-occurring species where resources are limited, species may either partition resources in space and/or time or exhibit differing efficiencies in the use of limited resources. Therefore, this study...

  9. Socioeconomic differentials and availability of domestic water in South Africa

    NASA Astrophysics Data System (ADS)

    Dungumaro, Esther W.

    The past few decades has seen massive efforts to increasing provision of domestic water. However, water is still unavailable to many people most of them located in sub-Saharan Africa, South Asia and East Asia. Furthermore, availability of water varies greatly both spatially and temporary. While other people pay so dearly for domestic water others have an easy access to adequate clean water and sanitation. Accessibility and affordability of domestic water and sanitation is determined by a great variety of factors including socioeconomic status of households. The main objective of the paper is to inform on factors which need to be taken into account when coming up with projects to provide domestic water. It is more critical when the issue of water pricing comes into the equation. Water pricing has many facets, including equity, willingness to pay and affordability. In this premise, it is deemed important to understand the socioeconomic characteristics of the people before deciding on the amount of money they will have to pay for water consumption. It is argued that understanding people’s socioeconomic situation will greatly help to ensure that principles of sustainability and equity in water allocation and pricing are achieved. To do so, the paper utilized 2002 South Africa General Household Survey (GHS), to analyze socioeconomic variables and availability of domestic water. Analysis was mainly descriptive. However, logistic regression analysis was also utilized to determine the likelihood of living in a household that obtain water from a safe source. The study found that there is a strong relationship between availability of domestic water and socioeconomic conditions. Economic status, household size and to a lesser extent gender of head of household were found to be strong predictors of living in a household which obtained water from a safe source. The paper recommends that needs and priorities for interventions in water provision should take into account

  10. Influence of free water availability on a desert carnivore and herbivore.

    PubMed

    Kluever, Bryan M; Gese, Eric M; Dempsey, Steven J

    2017-04-01

    Anthropogenic manipulation of finite resources on the landscape to benefit individual species or communities is commonly employed by conservation and management agencies. One such action in arid regions is the construction and maintenance of water developments (i.e., wildlife guzzlers) adding free water on the landscape to buttress local populations, influence animal movements, or affect distributions of certain species of interest. Despite their prevalence, the utility of wildlife guzzlers remains largely untested. We employed a before-after control-impact (BACI) design over a 4-year period on the US Army Dugway Proving Ground, Utah, USA, to determine whether water availability at wildlife guzzlers influenced relative abundance of black-tailed jackrabbits Lepus californicus and relative use of areas near that resource by coyotes Canis latrans , and whether coyote visitations to guzzlers would decrease following elimination of water. Eliminating water availability at guzzlers did not influence jackrabbit relative abundance. Coyote relative use was impacted by water availability, with elimination of water reducing use in areas associated with our treatment, but not with areas associated with our control. Visitations of radio-collared coyotes to guzzlers declined nearly 3-fold following elimination of water. Our study provides the first evidence of a potential direct effect of water sources on a mammalian carnivore in an arid environment, but the ecological relevance of our finding is debatable. Future investigations aimed at determining water effects on terrestrial mammals could expand on our findings by incorporating manipulations of water availability, obtaining absolute estimates of population parameters and vital rates and incorporating fine-scale spatiotemporal data.

  11. Influence of free water availability on a desert carnivore and herbivore

    PubMed Central

    Gese, Eric M.; Dempsey, Steven J.

    2017-01-01

    Abstract Anthropogenic manipulation of finite resources on the landscape to benefit individual species or communities is commonly employed by conservation and management agencies. One such action in arid regions is the construction and maintenance of water developments (i.e., wildlife guzzlers) adding free water on the landscape to buttress local populations, influence animal movements, or affect distributions of certain species of interest. Despite their prevalence, the utility of wildlife guzzlers remains largely untested. We employed a before–after control-impact (BACI) design over a 4-year period on the US Army Dugway Proving Ground, Utah, USA, to determine whether water availability at wildlife guzzlers influenced relative abundance of black-tailed jackrabbits Lepus californicus and relative use of areas near that resource by coyotes Canis latrans, and whether coyote visitations to guzzlers would decrease following elimination of water. Eliminating water availability at guzzlers did not influence jackrabbit relative abundance. Coyote relative use was impacted by water availability, with elimination of water reducing use in areas associated with our treatment, but not with areas associated with our control. Visitations of radio-collared coyotes to guzzlers declined nearly 3-fold following elimination of water. Our study provides the first evidence of a potential direct effect of water sources on a mammalian carnivore in an arid environment, but the ecological relevance of our finding is debatable. Future investigations aimed at determining water effects on terrestrial mammals could expand on our findings by incorporating manipulations of water availability, obtaining absolute estimates of population parameters and vital rates and incorporating fine-scale spatiotemporal data. PMID:29491969

  12. Simulations and field observations of root water uptake in plots with different soil water availability.

    NASA Astrophysics Data System (ADS)

    Cai, Gaochao; Vanderborght, Jan; Couvreur, Valentin; Javaux, Mathieu; Vereecken, Harry

    2015-04-01

    Root water uptake is a main process in the hydrological cycle and vital for water management in agronomy. In most models of root water uptake, the spatial and temporal soil water status and plant root distributions are required for water flow simulations. However, dynamic root growth and root distributions are not easy and time consuming to measure by normal approaches. Furthermore, root water uptake cannot be measured directly in the field. Therefore, it is necessary to incorporate monitoring data of soil water content and potential and root distributions within a modeling framework to explore the interaction between soil water availability and root water uptake. But, most models are lacking a physically based concept to describe water uptake from soil profiles with vertical variations in soil water availability. In this contribution, we present an experimental setup in which root development, soil water content and soil water potential are monitored non-invasively in two field plots with different soil texture and for three treatments with different soil water availability: natural rain, sheltered and irrigated treatment. Root development is monitored using 7-m long horizontally installed minirhizotubes at six depths with three replicates per treatment. The monitoring data are interpreted using a model that is a one-dimensional upscaled version of root water uptake model that describes flow in the coupled soil-root architecture considering water potential gradients in the system and hydraulic conductances of the soil and root system (Couvreur et al., 2012). This model approach links the total root water uptake to an effective soil water potential in the root zone. The local root water uptake is a function of the difference between the local soil water potential and effective root zone water potential so that compensatory uptake in heterogeneous soil water potential profiles is simulated. The root system conductance is derived from inverse modelling using

  13. Limited school drinking water access for youth

    PubMed Central

    Kenney, Erica L.; Gortmaker, Steven L.; Cohen, Juliana F.W.; Rimm, Eric B.; Cradock, Angie L.

    2016-01-01

    PURPOSE Providing children and youth with safe, adequate drinking water access during school is essential for health. This study utilized objectively measured data to investigate the extent to which schools provide drinking water access that meets state and federal policies. METHODS We visited 59 middle and high schools in Massachusetts during spring 2012. Trained research assistants documented the type, location, and working condition of all water access points throughout each school building using a standard protocol. School food service directors (FSDs) completed surveys reporting water access in cafeterias. We evaluated school compliance with state plumbing codes and federal regulations and compared FSD self-reports of water access with direct observation; data were analyzed in 2014. RESULTS On average, each school had 1.5 (SD: 0.6) water sources per 75 students; 82% (SD: 20) were functioning, and fewer (70%) were both clean and functioning. Less than half of the schools met the federal Healthy Hunger Free Kids Act requirement for free water access during lunch; 18 schools (31%) provided bottled water for purchase but no free water. Slightly over half (59%) met the Massachusetts state plumbing code. FSDs overestimated free drinking water access compared to direct observation (96% FSD-reported versus 48% observed, kappa=0.07, p=0.17). CONCLUSIONS School drinking water access may be limited. In this study, many schools did not meet state or federal policies for minimum student drinking water access. School administrative staff may not accurately report water access. Public health action is needed to increase school drinking water access. IMPLICATIONS AND CONTRIBUTIONS Adolescents’ water consumption is lower than recommended. In a sample of Massachusetts middle and high schools, about half did not meet federal and state minimum drinking water access policies. Direct observation may improve assessments of drinking water access and could be integrated into routine

  14. Availability of groundwater data for California, water year 2010

    USGS Publications Warehouse

    Ray, Mary; Orlando, Patricia v.P.

    2011-01-01

    The U.S. Geological Survey, in cooperation with Federal, State, and local agencies, obtains a large amount of data pertaining to the groundwater resources of California each water year (October 1-September 30). These data constitute a valuable database for developing an improved understanding of the water resources of the State. This Fact Sheet serves as an index to groundwater data for Water Year 2010. It contains a map of California showing the number of wells (by county) with available water-level or water-quality data for Water Year 2010 (fig. 1) and instructions for obtaining this and other groundwater information contained in the databases of the U.S. Geological Survey, California Water Science Center. From 1985 to 1993, data were published in the annual report "Water Resources Data for California, Volume 5. Ground-Water Data"; prior to 1985, the data were published in U.S. Geological Survey Water-Supply Papers.

  15. Metropolitan Water Availability Forecasting Methods and Applications in South Florida

    EPA Science Inventory

    The availability of adequate fresh water is fundamental to the sustainable management of water infrastructures that support both urban needs and agricultural uses in human society. Recent drought events in the U.S. have threatened drinking water supplies for communities in Maryl...

  16. Water availability as dominant control of heat stress responses in two contrasting tree species.

    PubMed

    Ruehr, Nadine K; Gast, Andreas; Weber, Christina; Daub, Baerbel; Arneth, Almut

    2016-02-01

    Heat waves that trigger severe droughts are predicted to increase globally; however, we lack an understanding of how trees respond to the combined change of extreme temperatures and water availability. Here, we studied the impacts of two consecutive heat waves as well as post-stress recovery in young Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) and Robinia pseudoacacia L. (black locust) growing under controlled conditions. Responses were compared under water supply close to the long-term average and under reduced irrigation to represent drought. Exposure to high temperatures (+10 °C above ambient) and vapour pressure deficit strongly affected the trees in terms of water relations, photosynthesis and growth. Douglas-fir used water resources conservatively, and transpiration decreased in response to mild soil water limitation. In black locust, heat stress led to pronounced tree water deficits (stem diameter shrinkage), accompanied by leaf shedding to alleviate stress on the hydraulic system. The importance of water availability during the heat waves became further apparent by a concurrent decline in photosynthesis and stomatal conductance with increasing leaf temperatures in both species, reaching the lowest rates in the heat-drought treatments. Stress severity determined both the speed and the amount of recovery. Upon release of stress, photosynthesis recovered rapidly in drought-treated black locust, while it remained below control rates in heat (t = -2.4, P < 0.05) and heat-drought stressed trees (t = 2.96, P < 0.05). In Douglas-fir, photosynthesis recovered quickly, while water-use efficiency increased in heat-drought trees because stomatal conductance remained reduced (t = -2.92, P < 0.05). Moreover, Douglas-fir was able to compensate for stem-growth reductions following heat (-40%) and heat-drought stress (-68%), but most likely at the expense of storage and other growth processes. Our results highlight the importance of studying heat waves alongside

  17. Limited School Drinking Water Access for Youth.

    PubMed

    Kenney, Erica L; Gortmaker, Steven L; Cohen, Juliana F W; Rimm, Eric B; Cradock, Angie L

    2016-07-01

    Providing children and youth with safe, adequate drinking water access during school is essential for health. This study used objectively measured data to investigate the extent to which schools provide drinking water access that meets state and federal policies. We visited 59 middle and high schools in Massachusetts during spring 2012. Trained research assistants documented the type, location, and working condition of all water access points throughout each school building using a standard protocol. School food service directors (FSDs) completed surveys reporting water access in cafeterias. We evaluated school compliance with state plumbing codes and federal regulations and compared FSD self-reports of water access with direct observation; data were analyzed in 2014. On average, each school had 1.5 (standard deviation: .6) water sources per 75 students; 82% (standard deviation: 20) were functioning and fewer (70%) were both clean and functioning. Less than half of the schools met the federal Healthy Hunger-Free Kids Act requirement for free water access during lunch; 18 schools (31%) provided bottled water for purchase but no free water. Slightly over half (59%) met the Massachusetts state plumbing code. FSDs overestimated free drinking water access compared to direct observation (96% FSD reported vs. 48% observed, kappa = .07, p = .17). School drinking water access may be limited. In this study, many schools did not meet state or federal policies for minimum student drinking water access. School administrative staff may not accurately report water access. Public health action is needed to increase school drinking water access. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  18. 78 FR 20912 - Clean Water Act: Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9798-8] Clean Water Act: Availability of List Decisions.... SUMMARY: The Clean Water Act requires that States periodically submit, and EPA approve or disapprove... are not stringent enough to attain or maintain State water quality standards and for which total...

  19. Drinking water sources, availability, quality, access and utilization for goats in the Karak Governorate, Jordan.

    PubMed

    Al-Khaza'leh, Ja'far Mansur; Reiber, Christoph; Al Baqain, Raid; Valle Zárate, Anne

    2015-01-01

    Goat production is an important agricultural activity in Jordan. The country is one of the poorest countries in the world in terms of water scarcity. Provision of sufficient quantity of good quality drinking water is important for goats to maintain feed intake and production. This study aimed to evaluate the seasonal availability and quality of goats' drinking water sources, accessibility, and utilization in different zones in the Karak Governorate in southern Jordan. Data collection methods comprised interviews with purposively selected farmers and quality assessment of water sources. The provision of drinking water was considered as one of the major constraints for goat production, particularly during the dry season (DS). Long travel distances to the water sources, waiting time at watering points, and high fuel and labor costs were the key reasons associated with the problem. All the values of water quality (WQ) parameters were within acceptable limits of the guidelines for livestock drinking WQ with exception of iron, which showed slightly elevated concentration in one borehole source in the DS. These findings show that water shortage is an important problem leading to consequences for goat keepers. To alleviate the water shortage constraint and in view of the depleted groundwater sources, alternative water sources at reasonable distance have to be tapped and monitored for water quality and more efficient use of rainwater harvesting systems in the study area is recommended.

  20. Implementation of State Obligations and Responsibility Ensuring the Availability of Clean Water in Karimunjawa Islands

    NASA Astrophysics Data System (ADS)

    Rahayu; Soeprobowati, Tri Retnaningsih

    2018-02-01

    This article aims to analyze the implementation of state obligations and responsibility ensuring the availability of clean water as part of human rights in Karimunjawa islands. The analysis based on principle of the State obligations and responsibility to fulfill their citizen right. Water sources in Karimunjawa Islands is very limited. It depend on forest conservation. Around 9.600 peoples live in Karimunjawa Islands, but Karimunjawa is non groundwater basin region. It means, Karimunjawa doesn't have groundwater potential. The quantity of water depends on the season. The solution to maintain the sustainability of clean water is piping from water reservoir to residential areas. The problem is there are so many hotels in Karimunjawa islands, it disrupted the fulfillment of clean water. Besides utilizing water from reservoir, many hotels drilled the ground to get water. It had impact to the availibity of water in dry season and affected to fulfillment of water supply for Karimunjawa people. There is no specific regulation and policy to solve this problem. Clean water management is doing by Karimunjawa's people. Meanwhile, based on Mahkamah Konstitusi Decree number 85/PUU-XI/2013, state is a rights holder to dominate the water in accordance with the Articles 33 paragraph (2) and (3) UUD NRI 1945, so the government has an obligation to make a policy, regulations, management, and supervision.

  1. Understorey productivity in temperate grassy woodland responds to soil water availability but not to elevated [CO2 ].

    PubMed

    Collins, Luke; Bradstock, Ross A; Resco de Dios, Victor; Duursma, Remko A; Velasco, Sabrina; Boer, Matthias M

    2018-06-01

    Rising atmospheric [CO 2 ] and associated climate change are expected to modify primary productivity across a range of ecosystems globally. Increasing aridity is predicted to reduce grassland productivity, although rising [CO 2 ] and associated increases in plant water use efficiency may partially offset the effect of drying on growth. Difficulties arise in predicting the direction and magnitude of future changes in ecosystem productivity, due to limited field experimentation investigating climate and CO 2 interactions. We use repeat near-surface digital photography to quantify the effects of water availability and experimentally manipulated elevated [CO 2 ] (eCO 2 ) on understorey live foliage cover and biomass over three growing seasons in a temperate grassy woodland in south-eastern Australia. We hypothesised that (i) understorey herbaceous productivity is dependent upon soil water availability, and (ii) that eCO 2 will increase productivity, with greatest stimulation occurring under conditions of low water availability. Soil volumetric water content (VWC) determined foliage cover and growth rates over the length of the growing season (August to March), with low VWC (<0.1 m 3  m -3 ) reducing productivity. However, eCO 2 did not increase herbaceous cover and biomass over the duration of the experiment, or mitigate the effects of low water availability on understorey growth rates and cover. Our findings suggest that projected increases in aridity in temperate woodlands are likely to lead to reduced understorey productivity, with little scope for eCO 2 to offset these changes. © 2018 John Wiley & Sons Ltd.

  2. Water availability and subsidence in California's Central Valley

    USGS Publications Warehouse

    Faunt, Claudia C.; Sneed, Michelle

    2015-01-01

    California’s Central Valley covers about 52,000 square kilometers (km2) and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the broad alluvial filled structural trough, with an estimated value exceeding $20 billion per year (Faunt 2009) (Figure 1). Central Valley agriculture depends on state and federal water systems that divert surface water, predominantly originating from Sierra Nevada snowmelt, to agricultural fields. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture, as it grew, developed a reliance on groundwater for irrigation.

  3. Precipitation v. River Discharge Controls on Water Availability to Riparian Trees in the Rhône River Delta

    NASA Astrophysics Data System (ADS)

    Singer, M. B.; Sargeant, C. I.; Vallet-Coulomb, C.; Evans, C.; Bates, C. R.

    2014-12-01

    Water availability to riparian trees in lowlands is controlled through precipitation and its infiltration into floodplain soils, and through river discharge additions to the hyporheic water table. The relative contributions of both water sources to the root zone within river floodplains vary through time, depending on climatic fluctuations. There is currently limited understanding of how climatic fluctuations are expressed at local scales, especially in 'critical zone' hydrology, which is fundamental to the health and sustainability of riparian forest ecosystems. This knowledge is particularly important in water-stressed Mediterranean climate systems, considering climatic trends and projections toward hotter and drier growing seasons, which have the potential to dramatically reduce water availability to riparian forests. Our aim is to identify and quantify the relative contributions of hyporheic (discharge) water v. infiltrated precipitation to water uptake by riparian Mediterranean trees for several distinct hydrologic years, selected to isolate contrasts in water availability from these sources. Our approach includes isotopic analyses of water and tree-ring cellulose, mechanistic modeling of water uptake and wood production, and physically based modeling of subsurface hydrology. We utilize an extensive database of oxygen isotope (δ18O) measurements in surface water and precipitation alongside recent measurements of δ18O in groundwater and soil water and in tree-ring cellulose. We use a mechanistic model to back-calculate source water δ18O based on δ18O in cellulose and climate data. Finally, we test our results via 1-D hydrologic modeling of precipitation infiltration and water table rise and fall. These steps enable us to interpret hydrologic cycle variability within the 'critical zone' and their potential impact on riparian trees.

  4. Optimal crop selection and water allocation under limited water supply in irrigation

    NASA Astrophysics Data System (ADS)

    Stange, Peter; Grießbach, Ulrike; Schütze, Niels

    2015-04-01

    Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with limited water resources in irrigation systems, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand at the same time. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from optimized agronomic response on farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF). These functions take into account different soil types, crops and stochastically generated climate scenarios. The SCWPF's are used to compute the water demand considering different conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed which helps to evaluate combined water supply and demand management policies.

  5. Hindcast of water availability in regional aquifer systems using MODFLOW Farm Process

    USGS Publications Warehouse

    Schmid, Wolfgang; Hanson, Randall T.; Faunt, Claudia C.; Phillips, Steven P.

    2015-01-01

    Coupled groundwater and surface-water components of the hydrologic cycle can be simulated by the Farm Process for MODFLOW (MF-FMP) in both irrigated and non-irrigated areas and aquifer-storage and recovery systems. MF-FMP is being applied to three productive agricultural regions of different scale in the State of California, USA, to assess the availability of water and the impacts of alternative management decisions. Hindcast simulations are conducted for similar periods from the 1960s to near recent times. Historical groundwater pumpage is mostly unknown in one region (Central Valley) and is estimated by MF-FMP. In another region (Pajaro Valley), recorded pumpage is used to calibrate model-estimated pumpage. Multiple types of observations are used to estimate uncertain parameters, such as hydraulic, land-use, and farm properties. MF-FMP simulates how climate variability and water-import availability affect water demand and supply. MF-FMP can be used to predict water availability based on anticipated changes in anthropogenic or natural water demands. Keywords groundwater; surface-water; irrigation; water availability; response to climate variability/change

  6. 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.

  7. Water availability and land subsidence in the Central Valley, California, USA

    NASA Astrophysics Data System (ADS)

    Faunt, Claudia C.; Sneed, Michelle; Traum, Jon; Brandt, Justin T.

    2016-05-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007-2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  8. 78 FR 45925 - Clean Water Act: Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-30

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9840-5] Clean Water Act: Availability of List Decisions... numeric water quality standards marine criterion for dissolved oxygen was not attained in these segments... 6's Web site at http://www.epa.gov/region6/water/npdes/tmdl/index.htm#303dlists , or by writing or...

  9. Assessment of water availability and demand in Lake Guiers , Senegal.

    NASA Astrophysics Data System (ADS)

    Sambou, D.; Weihrauch, D.; Hellwing, V.; Diekkrüger, B.; Höllermann, B.; Gaye, A. T.

    2015-12-01

    Assessment of water availability and demand in Lake Guiers, SenegalWater resources are critical to economic growth and social development. In most African countries, supply of drinking water to satisfy population needs is a key issue because of population growth and climate and land use change. During the last three decades, increasing population, changing patterns of water demand, and concentration of population and economic activities in urban areas has pressurize Senegal's freshwater resources. To overcome this deficit, Senegal turned, to the exploitation of the Lake Guiers. It is the sole water reservoir which can be used extensively as a stable freshwater. Its water is use for irrigating crops and sugar refinery and as a drinking water resource for urban centres, including Dakar, the capital city of Senegal, as well as for the local population and animal herds. To ensure sustainability, a greater understanding of Lake Guiers's water resources and effective management of its use will be required. In this study we developed and quantified future water situation (water availability and demand) in Lake Guiers under scenarios of climate change and population growth until 2050, using the water management model WEAP (Water Evaluation And Planning system). The results show that the pressure on Lake Guiers's water resources will increase, leading to greater competition between agriculture and municipal demand site. Decreasing inflows due to climate change will aggravate this situation. WEAP results offer basis to assister lake Guiers water resources manager for an efficient long-term planning and management. Keywords: climate change, population growth , IWRM, Lake Guiers, Senegal

  10. Floral longevity and autonomous selfing are altered by pollination and water availability in Collinsia heterophylla.

    PubMed

    Jorgensen, Rachael; Arathi, H S

    2013-09-01

    A plant investing in reproduction partitions resources between flowering and seed production. Under resource limitation, altered allocations may result in floral trait variations, leading to compromised fecundity. Floral longevity and timing of selfing are often the traits most likely to be affected. The duration of corolla retention determines whether fecundity results from outcrossing or by delayed selfing-mediated reproductive assurance. In this study, the role of pollination schedules and soil water availability on floral longevity and seed production is tested in Collinsia heterophylla (Plantaginaceae). Using three different watering regimes and pollination schedules, effects on floral longevity and seed production were studied in this protandrous, flowering annual. The results reveal that soil water status and pollination together influence floral longevity with low soil water and hand-pollinations early in the floral lifespan reducing longevity. However, early pollinations under excess water did not extend longevity, implying that resource surplus does not lengthen the outcrossing period. The results also indicate that pollen receipt, a reliable cue for fecundity, accelerates flower drop. Early corolla abscission under drought stress could potentially exacerbate sexual conflict in this protandrous, hermaphroditic species by ensuring self-pollen paternity and enabling male control of floral longevity. While pollination schedules did not affect fecundity, water stress reduced per-capita seed numbers. Unmanipulated flowers underwent delayed autonomous selfing, producing very few seeds, suggesting that inbreeding depression may limit benefits of selfing. In plants where herkogamy and dichogamy facilitate outcrossing, floral longevity determines reproductive success and mating system. Reduction in longevity under drought suggests a strong environmental effect that could potentially alter the preferred breeding mode in this mixed-mated species. Extrapolating the

  11. Climatic correlates of tree mortality in water- and energy-limited forests

    USGS Publications Warehouse

    Das, Adrian J.; Stephenson, Nathan L.; Flint, Alan; Das, Tapash; van Mantgem, Phillip J.

    2013-01-01

    Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1) drought stress, or (2) the effectiveness of tree-killing insects and pathogens. Using long-term data from California’s Sierra Nevada mountain range, we found that in water-limited (low-elevation) forests mortality was unambiguously best modeled by climatic water deficit, consistent with the first mechanism. In energy-limited (high-elevation) forests deficit models were only equivocally better than temperature models, suggesting that the second mechanism is increasingly important in these forests. We could not distinguish between models predicting mortality using absolute versus relative changes in water deficit, and these two model types led to different forecasts of mortality vulnerability under future climate scenarios. Our results provide evidence for differing climatic controls of tree mortality in water- and energy-limited forests, while highlighting the need for an improved understanding of tree mortality processes.

  12. Climatic correlates of tree mortality in water- and energy-limited forests.

    PubMed

    Das, Adrian J; Stephenson, Nathan L; Flint, Alan; Das, Tapash; van Mantgem, Phillip J

    2013-01-01

    Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1) drought stress, or (2) the effectiveness of tree-killing insects and pathogens. Using long-term data from California's Sierra Nevada mountain range, we found that in water-limited (low-elevation) forests mortality was unambiguously best modeled by climatic water deficit, consistent with the first mechanism. In energy-limited (high-elevation) forests deficit models were only equivocally better than temperature models, suggesting that the second mechanism is increasingly important in these forests. We could not distinguish between models predicting mortality using absolute versus relative changes in water deficit, and these two model types led to different forecasts of mortality vulnerability under future climate scenarios. Our results provide evidence for differing climatic controls of tree mortality in water- and energy-limited forests, while highlighting the need for an improved understanding of tree mortality processes.

  13. Prediction in Ungauged Basins (PUB) for estimating water availability during water scarcity conditions: rainfall-runoff modelling of the ungauged diversion inflows to the Ridracoli water supply reservoir

    NASA Astrophysics Data System (ADS)

    Toth, Elena

    2013-04-01

    The Ridracoli reservoir is the main drinking water supply reservoir serving the whole Romagna region, in Northern Italy. Such water supply system has a crucial role in an area where the different characteristics of the communities to be served, their size, the mass tourism and the presence of food industries highlight strong differences in drinking water needs. Its operation allows high quality drinking water supply to a million resident customers, plus a few millions of tourists during the summer of people and it reduces the need for water pumping from underground sources, and this is particularly important since the coastal area is subject also to subsidence and saline ingression into aquifers. The system experienced water shortage conditions thrice in the last decade, in 2002, in 2007 and in autumn-winter 2011-2012, when the reservoir water storage fell below the attention and the pre-emergency thresholds, thus prompting the implementation of a set of mitigation measures, including limitations to the population's water consumption. The reservoir receives water not only from the headwater catchment, closed at the dam, but also from four diversion watersheds, linked to the reservoir through an underground water channel. Such withdrawals are currently undersized, abstracting only a part of the streamflow exceeding the established minimum flows, due to the design of the water intake structures; it is therefore crucial understanding how the reservoir water availability might be increased through a fuller exploitation of the existing diversion catchment area. Since one of the four diversion catchment is currently ungauged (at least at the fine temporal scale needed for keeping into account the minimum flow requirements downstream of the intakes), the study first presents the set up and parameterisation of a continuous rainfall-runoff model at hourly time-step for the three gauged diversion watersheds and for the headwater catchment: a regional parameterisation

  14. 40 CFR 439.44 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of best available technology economically achievable (BAT). 439.44 Section 439.44 Protection of... limitations attainable by the application of best available technology economically achievable (BAT). Except... achieve the following effluent limitations representing the application of BAT: The limitations for COD...

  15. 40 CFR 439.44 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of best available technology economically achievable (BAT). 439.44 Section 439.44 Protection of... limitations attainable by the application of best available technology economically achievable (BAT). Except... achieve the following effluent limitations representing the application of BAT: The limitations for COD...

  16. 40 CFR 439.44 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of best available technology economically achievable (BAT). 439.44 Section 439.44 Protection of... limitations attainable by the application of best available technology economically achievable (BAT). Except... achieve the following effluent limitations representing the application of BAT: The limitations for COD...

  17. Water limits to closing yield gaps

    NASA Astrophysics Data System (ADS)

    Davis, Kyle Frankel; Rulli, Maria Cristina; Garrassino, Francesco; Chiarelli, Davide; Seveso, Antonio; D'Odorico, Paolo

    2017-01-01

    Agricultural intensification is often seen as a suitable approach to meet the growing demand for agricultural products and improve food security. It typically entails the use of fertilizers, new cultivars, irrigation, and other modern technology. In regions of the world affected by seasonal or chronic water scarcity, yield gap closure is strongly dependent on irrigation (blue water). Global yield gap assessments have often ignored whether the water required to close the yield gap is locally available. Here we perform a gridded global analysis (10 km resolution) of the blue water consumption that is needed annually to close the yield gap worldwide and evaluate the associated pressure on renewable freshwater resources. We find that, to close the yield gap, human appropriation of freshwater resources for irrigation would have to increase at least by 146%. Most study countries would experience at least a doubling in blue water requirement, with 71% of the additional blue water being required by only four crops - maize, rice, soybeans, and wheat. Further, in some countries (e.g., Algeria, Morocco, Syria, Tunisia, and Yemen) the total volume of blue water required for yield gap closure would exceed sustainable levels of freshwater consumption (i.e., 40% of total renewable surface and groundwater resources).

  18. Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments

    PubMed Central

    2017-01-01

    Plant performance (i.e., fecundity, growth, survival) depends on an individual’s access to space and resources. At the community level, plant performance is reflected in observable vegetation patterning (i.e., spacing distance, density) often controlled by limiting resources. Resource availability is, in turn, strongly dependent on plant patterning mediated by competitive and facilitative plant–plant interactions. Co-occurring competition and facilitation has never been specifically investigated from a hydrodynamic perspective. To address this knowledge gap, and to overcome limitations of field studies, three intermediate-scale laboratory experiments were conducted using a climate-controlled wind tunnel–porous media test facility to simulate the soil–plant–atmosphere continuum. The spacing between two synthetic plants, a design consideration introduced by the authors in a recent publication, was varied between experiments; edaphic and mean atmospheric conditions were held constant. The strength of the above- and belowground plant–plant interactions changed with spacing distance, allowing the creation of a hydrodynamic conceptual model based on established ecological theories. Greatest soil water loss was observed for the experiment with the smallest spacing where competition dominated. Facilitation dominated at the intermediate spacing; little to no interactions were observed for the largest plant spacing. Results suggest that there exists an optimal spacing distance range that lowers plant environmental stress, thus improving plant performance through reduced atmospheric demand and conservation of available soil water. These findings may provide a foundation for improving our understanding of many climatological, ecohydrological, and hydrological problems pertaining to the hydrodynamics of water-limited environments where plant–plant interactions and community self-organization are important. PMID:28807999

  19. Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments.

    PubMed

    Trautz, Andrew C; Illangasekare, Tissa H; Rodriguez-Iturbe, Ignacio

    2017-08-29

    Plant performance (i.e., fecundity, growth, survival) depends on an individual's access to space and resources. At the community level, plant performance is reflected in observable vegetation patterning (i.e., spacing distance, density) often controlled by limiting resources. Resource availability is, in turn, strongly dependent on plant patterning mediated by competitive and facilitative plant-plant interactions. Co-occurring competition and facilitation has never been specifically investigated from a hydrodynamic perspective. To address this knowledge gap, and to overcome limitations of field studies, three intermediate-scale laboratory experiments were conducted using a climate-controlled wind tunnel-porous media test facility to simulate the soil-plant-atmosphere continuum. The spacing between two synthetic plants, a design consideration introduced by the authors in a recent publication, was varied between experiments; edaphic and mean atmospheric conditions were held constant. The strength of the above- and belowground plant-plant interactions changed with spacing distance, allowing the creation of a hydrodynamic conceptual model based on established ecological theories. Greatest soil water loss was observed for the experiment with the smallest spacing where competition dominated. Facilitation dominated at the intermediate spacing; little to no interactions were observed for the largest plant spacing. Results suggest that there exists an optimal spacing distance range that lowers plant environmental stress, thus improving plant performance through reduced atmospheric demand and conservation of available soil water. These findings may provide a foundation for improving our understanding of many climatological, ecohydrological, and hydrological problems pertaining to the hydrodynamics of water-limited environments where plant-plant interactions and community self-organization are important.

  20. Water availability and land subsidence in the Central Valley, California, USA

    USGS Publications Warehouse

    Faunt, Claudia; Sneed, Michelle; Traum, Jonathan A.; Brandt, Justin

    2016-01-01

    The Central Valley in California (USA) covers about 52,000 km2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  1. Climate impacts on human livelihoods: where uncertainty matters in projections of water availability

    NASA Astrophysics Data System (ADS)

    Lissner, T. K.; Reusser, D. E.; Schewe, J.; Lakes, T.; Kropp, J. P.

    2014-03-01

    Climate change will have adverse impacts on many different sectors of society, with manifold consequences for human livelihoods and well-being. However, a systematic method to quantify human well-being and livelihoods across sectors is so far unavailable, making it difficult to determine the extent of such impacts. Climate impact analyses are often limited to individual sectors (e.g. food or water) and employ sector-specific target-measures, while systematic linkages to general livelihood conditions remain unexplored. Further, recent multi-model assessments have shown that uncertainties in projections of climate impacts deriving from climate and impact models as well as greenhouse gas scenarios are substantial, posing an additional challenge in linking climate impacts with livelihood conditions. This article first presents a methodology to consistently measure Adequate Human livelihood conditions for wEll-being And Development (AHEAD). Based on a transdisciplinary sample of influential concepts addressing human well-being, the approach measures the adequacy of conditions of 16 elements. We implement the method at global scale, using results from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) to show how changes in water availability affect the fulfilment of AHEAD at national resolution. In addition, AHEAD allows identifying and differentiating uncertainty of climate and impact model projections. We show how the approach can help to put the substantial inter-model spread into the context of country-specific livelihood conditions by differentiating where the uncertainty about water scarcity is relevant with regard to livelihood conditions - and where it is not. The results indicate that in many countries today, livelihood conditions are compromised by water scarcity. However, more often, AHEAD fulfilment is limited through other elements. Moreover, the analysis shows that for 44 out of 111 countries, the water-specific uncertainty ranges are

  2. Availability of water from the Outwash Aquifer, Marion County, Indiana

    USGS Publications Warehouse

    Smith, B.S.

    1983-01-01

    The outwash aquifer in Marion County, Indiana is a continuous, unconfined sand and gravel deposit containing isolated boulder, till, silt, and clay deposits along the White River, Fall Creek, and Eagle Creek. Flow in the aquifer is from the boundaries of the aquifer with the Tipton till plain toward the streams and major pumping centers in the aquifer. A two-dimensional, finite-difference model of the outwash aquifer was calibrated to water levels of October 6 to 10, 1980 and used to estimate availability of water in the aquifer. A drawdown limit of 50-percent saturated thickness applied to 78 simulated-pumping wells assumed to be 1 foot in diameter produced 97 cubic feet per second from the outwash aquifer. Streamflow reductions caused by 97 cubic feet per second simulated pumpage and constant-flux boundaries were estimated to be 85 cubic feet per second in the White River and 12 cubic feet per second in Fall Creek. In comparison, the 7-day, 10-year low flows were 83 cubic feet per second in the White River near Nora and 23 cubic feet per second in Fall Creek at Millersville. Simulated pumpage of 115 cubic feet per second and constant-flux boundaries produced streamflow reductions of 101 cubic feet per second on the White River and 13 cubic feet per second on Fall Creek. (USGS)

  3. Global Floods and Water Availability Driven by Atmospheric Rivers

    NASA Astrophysics Data System (ADS)

    Paltan, Homero; Waliser, Duane; Lim, Wee Ho; Guan, Bin; Yamazaki, Dai; Pant, Raghav; Dadson, Simon

    2017-10-01

    While emerging regional evidence shows that atmospheric rivers (ARs) can exert strong impacts on local water availability and flooding, their role in shaping global hydrological extremes has not yet been investigated. Here we quantify the relative contribution of ARs variability to both flood hazard and water availability. We find that globally, precipitation from ARs contributes 22% of total global runoff, with a number of regions reaching 50% or more. In areas where their influence is strongest, ARs may increase the occurrence of floods by 80%, while absence of ARs may increase the occurrence of hydrological droughts events by up to 90%. We also find that 300 million people are exposed to additional floods and droughts due the occurrence of ARs. ARs provide a source of hydroclimatic variability whose beneficial or damaging effects depend on the capacity of water resources managers to predict and adapt to them.

  4. Open Source Tools for Assessment of Global Water Availability, Demands, and Scarcity

    NASA Astrophysics Data System (ADS)

    Li, X.; Vernon, C. R.; Hejazi, M. I.; Link, R. P.; Liu, Y.; Feng, L.; Huang, Z.; Liu, L.

    2017-12-01

    Water availability and water demands are essential factors for estimating water scarcity conditions. To reproduce historical observations and to quantify future changes in water availability and water demand, two open source tools have been developed by the JGCRI (Joint Global Change Research Institute): Xanthos and GCAM-STWD. Xanthos is a gridded global hydrologic model, designed to quantify and analyze water availability in 235 river basins. Xanthos uses a runoff generation and a river routing modules to simulate both historical and future estimates of total runoff and streamflows on a monthly time step at a spatial resolution of 0.5 degrees. GCAM-STWD is a spatiotemporal water disaggregation model used with the Global Change Assessment Model (GCAM) to spatially downscale global water demands for six major enduse sectors (irrigation, domestic, electricity generation, mining, and manufacturing) from the region scale to the scale of 0.5 degrees. GCAM-STWD then temporally downscales the gridded annual global water demands to monthly results. These two tools, written in Python, can be integrated to assess global, regional or basin-scale water scarcity or water stress. Both of the tools are extensible to ensure flexibility and promote contribution from researchers that utilize GCAM and study global water use and supply.

  5. Global assessment of predictability of water availability: A bivariate probabilistic Budyko analysis

    NASA Astrophysics Data System (ADS)

    Wang, Weiguang; Fu, Jianyu

    2018-02-01

    Estimating continental water availability is of great importance for water resources management, in terms of maintaining ecosystem integrity and sustaining society development. To more accurately quantify the predictability of water availability, on the basis of univariate probabilistic Budyko framework, a bivariate probabilistic Budyko approach was developed using copula-based joint distribution model for considering the dependence between parameter ω of Wang-Tang's equation and the Normalized Difference Vegetation Index (NDVI), and was applied globally. The results indicate the predictive performance in global water availability is conditional on the climatic condition. In comparison with simple univariate distribution, the bivariate one produces the lower interquartile range under the same global dataset, especially in the regions with higher NDVI values, highlighting the importance of developing the joint distribution by taking into account the dependence structure of parameter ω and NDVI, which can provide more accurate probabilistic evaluation of water availability.

  6. Climate impacts on human livelihoods: where uncertainty matters in projections of water availability

    NASA Astrophysics Data System (ADS)

    Lissner, T. K.; Reusser, D. E.; Schewe, J.; Lakes, T.; Kropp, J. P.

    2014-10-01

    Climate change will have adverse impacts on many different sectors of society, with manifold consequences for human livelihoods and well-being. However, a systematic method to quantify human well-being and livelihoods across sectors is so far unavailable, making it difficult to determine the extent of such impacts. Climate impact analyses are often limited to individual sectors (e.g. food or water) and employ sector-specific target measures, while systematic linkages to general livelihood conditions remain unexplored. Further, recent multi-model assessments have shown that uncertainties in projections of climate impacts deriving from climate and impact models, as well as greenhouse gas scenarios, are substantial, posing an additional challenge in linking climate impacts with livelihood conditions. This article first presents a methodology to consistently measure what is referred to here as AHEAD (Adequate Human livelihood conditions for wEll-being And Development). Based on a trans-disciplinary sample of concepts addressing human well-being and livelihoods, the approach measures the adequacy of conditions of 16 elements. We implement the method at global scale, using results from the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP) to show how changes in water availability affect the fulfilment of AHEAD at national resolution. In addition, AHEAD allows for the uncertainty of climate and impact model projections to be identified and differentiated. We show how the approach can help to put the substantial inter-model spread into the context of country-specific livelihood conditions by differentiating where the uncertainty about water scarcity is relevant with regard to livelihood conditions - and where it is not. The results indicate that livelihood conditions are compromised by water scarcity in 34 countries. However, more often, AHEAD fulfilment is limited through other elements. The analysis shows that the water-specific uncertainty ranges of the

  7. Climatic Correlates of Tree Mortality in Water- and Energy-Limited Forests

    PubMed Central

    Das, Adrian J.; Stephenson, Nathan L.; Flint, Alan; Das, Tapash; van Mantgem, Phillip J.

    2013-01-01

    Recent increases in tree mortality rates across the western USA are correlated with increasing temperatures, but mechanisms remain unresolved. Specifically, increasing mortality could predominantly be a consequence of temperature-induced increases in either (1) drought stress, or (2) the effectiveness of tree-killing insects and pathogens. Using long-term data from California’s Sierra Nevada mountain range, we found that in water-limited (low-elevation) forests mortality was unambiguously best modeled by climatic water deficit, consistent with the first mechanism. In energy-limited (high-elevation) forests deficit models were only equivocally better than temperature models, suggesting that the second mechanism is increasingly important in these forests. We could not distinguish between models predicting mortality using absolute versus relative changes in water deficit, and these two model types led to different forecasts of mortality vulnerability under future climate scenarios. Our results provide evidence for differing climatic controls of tree mortality in water- and energy-limited forests, while highlighting the need for an improved understanding of tree mortality processes. PMID:23936118

  8. Do shallow soil, low water availability, or their combination increase the competition between grasses with different root systems in karst soil?

    PubMed

    Zhao, Yajie; Li, Zhou; Zhang, Jing; Song, Haiyan; Liang, Qianhui; Tao, Jianping; Cornelissen, Johannes H C; Liu, Jinchun

    2017-04-01

    Uneven soil depth and low water availability are the key limiting factors to vegetation restoration and reconstruction in limestone soils such as in vulnerable karst regions. Belowground competition will possibly increase under limited soil resources. Here, we investigate whether low resource availability (including shallow soil, low water availability, and shallow soil and low water availability combined) stimulates the competition between grasses with different root systems in karst soil, by assessing their growth response, biomass allocation, and morphological plasticity. In a full three-way factorial blocked design of soil depth by water availability by neighbor identity, we grew Festuca arundinacea (deep-rooted) and Lolium perenne (shallow-rooted) under normal versus shallow soil depth, high versus low water availability, and in monoculture (conspecific neighbor) versus mixture (neighbor of the other species). The key results were as follows: (1) total biomass and aboveground biomass in either of the species decreased with reduction of resources but were not affected by planting patterns (monoculture or mixture) even at low resource levels. (2) For F. arundinacea, root biomass, root mass fraction, total root length, and root volume were higher in mixture than in monoculture at high resource level (consistent with resource use complementarity), but lower in mixture than in monoculture at low resource levels (consistent with interspecific competition). In contrast for L. perenne, either at high or low resource level, these root traits had mostly similar values at both planting patterns. These results suggest that deep-rooted and shallow-rooted plant species can coexist in karst regions under current climatic regimes. Declining resources, due to shallow soil, a decrease in precipitation, or combined shallow soil and karst drought, increased the root competition between plants of deep-rooted and shallow-rooted species. The root systems of deep-rooted plants may be

  9. Pesticides water decontamination in oxygen-limited conditions.

    PubMed

    Suciu, Nicoleta Alina; Ferrari, Federico; Vasileiadis, Sotirios; Merli, Annalisa; Capri, Ettore; Trevisan, Marco

    2013-01-01

    This study was undertaken to develop a laboratory bioreactor, with a functioning principle similar with that of biobed systems but working in oxygen-limited conditions, suitable for decontaminating wastewater mixtures with pesticides. The system is composed by two cylindrical plastic containers. The first one, where the pesticides solution is collected, is open, whereas the second one, where the biomass is disposed, is closed. The pesticides solution was pumped at the biomass surface and subsequently recollected and disposed in the first container. Four pesticides with different physical-chemical characteristics were tested. The results obtained showed a relatively good capacity of the developed prototype to decontaminate waste water containing the mixture of pesticides. The time of the experiment, the number of cycles that the solution made in the system and the environmental temperature have a significantly influence for the decontamination of acetochlor and chlorpyrifos whereas for the decontamination of terbuthylazine and metalaxyl no significant influence was observed. Even if the present prototype could represent a valid solution to manage the water pesticides residues in a farm and to increase the confidence of bystanders and residents, the practical difficulties when replacing the biomass could represent a limit of the system.

  10. Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

    NASA Astrophysics Data System (ADS)

    Skaggs, T. H.; Anderson, R. G.; Corwin, D. L.; Suarez, D. L.

    2014-12-01

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems modeling framework that accounts for reduced plant water uptake due to root zone salinity. Two explicit, closed-form analytical solutions for the root zone solute concentration profile are obtained, corresponding to two alternative functional forms of the uptake reduction function. The solutions express a general relationship between irrigation water salinity, irrigation rate, crop salt tolerance, crop transpiration, and (using standard approximations) crop yield. Example applications are illustrated, including the calculation of irrigation requirements for obtaining targeted submaximal yields, and the generation of crop-water production functions for varying irrigation waters, irrigation rates, and crops. Model predictions are shown to be mostly consistent with existing models and available experimental data. Yet the new solutions possess advantages over available alternatives, including: (i) the solutions were derived from a complete physical-mathematical description of the system, rather than based on an ad hoc formulation; (ii) the analytical solutions are explicit and can be evaluated without iterative techniques; (iii) the solutions permit consideration of two common functional forms of salinity induced reductions in crop water uptake, rather than being tied to one particular representation; and (iv) the utilized modeling framework is compatible with leading transient-state numerical models.

  11. Effects of irrigation water supply variations on limited resource farming in Conejos County, Colorado

    NASA Astrophysics Data System (ADS)

    Eckert, Jerry B.; Wang, Erda

    1993-02-01

    Farms in NE Conejos County, Colorado, are characterized by limited resources, uncertain surface flow irrigation systems, and mixed crop-livestock enterprise combinations which are dependent on public grazing resources. To model decision making on these farms, a linear program is developed stressing enterprise choices under conditions of multiple resource constraints. Differential access to grazing resources and irrigation water is emphasized in this research. Regarding the water resource, the model reflects farms situated alternatively on high-, medium-, and low-priority irrigation ditches within the Alamosa-La Jara river system, each with and without supplemental pumping. Differences are found in optimum enterprise mixes, net returns, choice of cropping technology, level of marketings, and other characteristics in response to variations in the availability of irrigation water. Implications are presented for alternative improvement strategies.

  12. Water availability and usage on the New Mexico/Mexico border.

    PubMed

    Li, Yongmei; Arnold, Stephen D; Kozel, Charles; Forster-Cox, Sue

    2005-10-01

    New Mexico, one of four states on the U.S./Mexico border, is faced with a pressing concern--lack of water. Since the region is either arid or semiarid, it is chronically short of continually available surface-water resources. Groundwater resources are used beyond their capacity to be recharged, and most surface-water resources are used to the maximum. The quality of groundwater varies widely. As a result of nonpoint- and point-source contamination, as well as natural occurrence, water in some areas is too salty or has high levels of natural uranium, fluoride, or arsenic. To date, the New Mexico Environment Department (NMED) has recognized 1,400 cases of groundwater contamination, and 1,907 water supply wells have been affected (NMED, 2001a). Of approximate 4,000 miles of coninously flowing rivers and streams in New Mexico, 92 perent are affected by nonpoint sources of pollution (NMED, 2001b). Numerous critical water issues exist along the New Mexico/Mexico border as a result of the impending critical issue of water availability, usage, and quality, as well as the fast-growing population. Related public health problems along the New Mexico/Mexico border are indicative of the need for a holistic, concrete, and sustainable solution to meet water demands in New Mexico. In order to accomplish the goals an objectives of Border XXI, Healthy People 2010, and Heathy Border 2010, a comprehensive statewide water management plan is needed. Solutions to the water demands of the region will be addressed in a subsequent manuscript.

  13. Alfalfa response to irrigation from limited water supplies

    USDA-ARS?s Scientific Manuscript database

    A five-year field study (2007-2011) of irrigated alfalfa production with a limited water supply was conducted in southwest Kansas with two years of above-average precipitation, one year of average precipitation, and two years of below-average precipitation. The irrigation treatments were designed to...

  14. Temperature of water available for industrial use in the United States: Chapter F in Contributions to the hydrology of the United States, 1923-1924

    USGS Publications Warehouse

    Collins, W.D.

    1925-01-01

    The importance of water supply as a limiting factor in industrial development is becoming more evident each year. The limitation in a particular instance may be the quantity of water available, the quality determined by the mineral matter in solution or in suspension or by organic pollution, or the temperature of the water. Generally it is a combination of two or more of these factors.Many publications of the Geological Survey give data in regard to the quantity of surface water and ground water obtainable at different points. Other publications of this Survey and of other organizations give data on the quality of waters available for industrial use. The temperature of these waters is discussed in the present report.Data in regard to ground water have been obtained from Geological Survey water-supply papers, from the publications indicated in footnotes, and from an unpublished compilation of temperature records prepared by C. E. Van Orstrand, of the Geological Survey, in connection with studies of deep earth temperature. Data on temperature of surface water have been obtained mainly from officials of waterworks, as noted in the accompanying table. Data on air temperature have been obtained from reports of the United States Weather Bureau. The maps showing temperature of ground water and surface water (Pls. VIII and IX) are taken directly from Weather Bureau charts of temperature distribution.

  15. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness

    PubMed Central

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010–2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate. PMID:26305893

  16. Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness.

    PubMed

    Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

    2015-01-01

    The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010-2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate.

  17. Drought, Land-Use Change, and Water Availability in California's Central Valley

    NASA Astrophysics Data System (ADS)

    Faunt, C. C.; Sneed, M.; Traum, J.

    2015-12-01

    The Central Valley is a broad alluvial-filled structural trough that covers about 52,000 square kilometers and is one of the most productive agricultural regions in the world. Because the valley is semi-arid and the availability of surface water varies substantially from year to year, season to season, and from north to south, agriculture developed a reliance on groundwater for irrigation. During recent drought periods (2007-09 and 2012-present), groundwater pumping has increased due to a combination of factors including drought and land-use changes. In response, groundwater levels have declined to levels approaching or below historical low levels. In the San Joaquin Valley, the southern two thirds of the Central Valley, the extensive groundwater pumpage has caused aquifer system compaction, resulting in land subsidence and permanent loss of groundwater storage capacity. The magnitude and rate of subsidence varies based on geologic materials, consolidation history, and historical water levels. Spatially-variable subsidence has changed the land-surface slope, causing operational, maintenance, and construction-design problems for surface-water infrastructure. It is important for water agencies to plan for the effects of continued water-level declines, storage losses, and/or land subsidence. To combat these effects, excess surface water, when available, is artificially recharged. As surface-water availability, land use, and artificial recharge continue to vary, long-term groundwater-level and land-subsidence monitoring and modelling are critical to understanding the dynamics of the aquifer system. Modeling tools, such as the Central Valley Hydrologic Model, can be used in the analysis and evaluation of management strategies to mitigate adverse impacts due to subsidence, while also optimizing water availability. These analyses will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

  18. Large Scale Evapotranspiration Estimates: An Important Component in Regional Water Balances to Assess Water Availability

    NASA Astrophysics Data System (ADS)

    Garatuza-Payan, J.; Yepez, E. A.; Watts, C.; Rodriguez, J. C.; Valdez-Torres, L. C.; Robles-Morua, A.

    2013-05-01

    Water security, can be defined as the reliable supply in quantity and quality of water to help sustain future populations and maintaining ecosystem health and productivity. Water security is rapidly declining in many parts of the world due to population growth, drought, climate change, salinity, pollution, land use change, over-allocation and over-utilization, among other issues. Governmental offices (such as the Comision Nacional del Agua in Mexico, CONAGUA) require and conduct studies to estimate reliable water balances at regional or continental scales in order to provide reasonable assessments of the amount of water that can be provided (from surface or ground water sources) to supply all the human needs while maintaining natural vegetation, on an operational basis and, more important, under disturbances, such as droughts. Large scale estimates of evapotranspiration (ET), a critical component of the water cycle, are needed for a better comprehension of the hydrological cycle at large scales, which, in most water balances is left as the residual. For operational purposes, such water balance estimates can not rely on ET measurements since they do not exist, should be simple and require the least ground information possible, information that is often scarce or does not exist at all. Given this limitation, the use of remotely sensed data to estimate ET could supplement the lack of ground information, particularly in remote regions In this study, a simple method, based on the Makkink equation is used to estimate ET for large areas at high spatial resolutions (1 km). The Makkink model used here is forced using three remotely sensed datasets. First, the model uses solar radiation estimates obtained from the Geostationary Operational Environmental Satellite (GOES); Second, the model uses an Enhanced Vegetation Index (EVI) obtained from the Moderate-resolution Imaging Spectroradiometer (MODIS) normalized to get an estimate for vegetation amount and land use which was

  19. 40 CFR 432.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.13 Section 432.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  20. 40 CFR 432.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.13 Section 432.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  1. 40 CFR 432.113 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.113 Section 432.113 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  2. 40 CFR 432.113 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.113 Section 432.113 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  3. 40 CFR 432.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.13 Section 432.13 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  4. 40 CFR 432.113 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.113 Section 432.113 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  5. 40 CFR 432.123 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.123 Section 432.123 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... the following effluent limitations representing the application of BAT: Effluent Limitations [BAT...

  6. 40 CFR 432.123 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.123 Section 432.123 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... the following effluent limitations representing the application of BAT: Effluent Limitations [BAT...

  7. 40 CFR 444.15 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 444.15 Section 444.15 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... must achieve the following effluent limitations representing the application of BAT: Limitations for...

  8. 40 CFR 444.15 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 444.15 Section 444.15 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... must achieve the following effluent limitations representing the application of BAT: Limitations for...

  9. 40 CFR 432.123 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.123 Section 432.123 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... the following effluent limitations representing the application of BAT: Effluent Limitations [BAT...

  10. Maximizing the value of limited irrigation water: USDA researchers study how producers on limited irrigation can save water and be profitable

    USDA-ARS?s Scientific Manuscript database

    Water shortages are responsible for the greatest crop losses around the world and are expected to worsen. In arid areas where agriculture is dependent on irrigation, various forms of deficit irrigation management have been suggested to optimize crop yields for available soil water. The relationshi...

  11. Estimated water use and availability in the South Coastal Drainage Basin, southern Rhode Island, 1995-99

    USGS Publications Warehouse

    Wild, Emily C.; Nimiroski, Mark T.

    2005-01-01

    The South Coastal Drainage Basin includes approximately 59.14 square miles in southern Rhode Island. The basin was divided into three subbasins to assess the water use and availability: the Saugatucket, Point Judith Pond, and the Southwestern Coastal Drainage subbasins. Because there is limited information on the ground-water system in this basin, the water use and availability evaluations for these subbasins were derived from delineated surface-water drainage areas. An assessment was completed to estimate water withdrawals, use, and return flow over a 5-year study period from 1995 through 1999 in the basin. During the study period, one major water supplier in the basin withdrew an average of 0.389 million gallons per day from the sand and gravel deposits. Most of the potable water is imported (about 2.152 million gallons per day) from the adjacent Pawcatuck Basin to the northwest. The estimated water withdrawals from the minor water suppliers, which are all in Charlestown, during the study period were 0.064 million gallons per day. The self-supplied domestic, industrial, commercial, and agricultural withdrawals from the basin were 0.574 million gallons per day. Water use in the basin was 2.874 million gallons per day. The average return flow in the basin was 1.190 million gallons per day, which was entirely from self-disposed water users. In this basin, wastewater from service collection areas was exported (about 1.139 million gallons per day) to the Narragansett Bay Drainage Basin for treatment and discharge. During times of little to no recharge, in the form of precipitation, the surface- and ground-water system flows are from storage primarily in the stratified sand and gravel deposits, although there is flow moving through the till deposits at a slower rate. The ground water discharging to the streams, during times of little to no precipitation, is referred to as base flow. The PART program, a computerized hydrograph-separation application, was used at the

  12. 40 CFR 439.14 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of best available technology economically achievable (BAT). 439.14 Section 439.14 Protection of... by the application of best available technology economically achievable (BAT). (a) Except as provided... following effluent limitations representing the application of BAT: Effluent Limitations (BAT) Regulated...

  13. 40 CFR 439.14 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of best available technology economically achievable (BAT). 439.14 Section 439.14 Protection of... by the application of best available technology economically achievable (BAT). (a) Except as provided... following effluent limitations representing the application of BAT: Effluent Limitations (BAT) Regulated...

  14. 40 CFR 439.14 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of best available technology economically achievable (BAT). 439.14 Section 439.14 Protection of... by the application of best available technology economically achievable (BAT). (a) Except as provided... following effluent limitations representing the application of BAT: Effluent Limitations (BAT) Regulated...

  15. 40 CFR 432.23 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.23 Section 432.23 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Limitations for ammonia (as N) and total nitrogen...

  16. 40 CFR 432.23 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.23 Section 432.23 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Limitations for ammonia (as N) and total nitrogen...

  17. 40 CFR 437.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 437.33 Section 437.33 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... this subpart must achieve limitations representing the application of BAT: Limitations for copper, zinc...

  18. 40 CFR 432.43 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.43 Section 432.43 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Limitations for ammonia (as N) and total nitrogen...

  19. 40 CFR 432.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.33 Section 432.33 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: the limitations for ammonia (as N) and total...

  20. 40 CFR 432.43 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.43 Section 432.43 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Limitations for ammonia (as N) and total nitrogen...

  1. 40 CFR 437.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 437.33 Section 437.33 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... this subpart must achieve limitations representing the application of BAT: Limitations for copper, zinc...

  2. 40 CFR 432.23 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.23 Section 432.23 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Limitations for ammonia (as N) and total nitrogen...

  3. 40 CFR 432.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.33 Section 432.33 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: the limitations for ammonia (as N) and total...

  4. 40 CFR 432.43 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.43 Section 432.43 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: Limitations for ammonia (as N) and total nitrogen...

  5. 40 CFR 432.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.33 Section 432.33 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... effluent limitations representing the application of BAT: the limitations for ammonia (as N) and total...

  6. Olive response to water availability: yield response functions, soil water content indicators and evaluation of adaptability to climate change

    NASA Astrophysics Data System (ADS)

    Riccardi, Maria; Alfieri, Silvia Maria; Basile, Angelo; Bonfante, Antonello; Menenti, Massimo; Monaco, Eugenia; De Lorenzi, Francesca

    2013-04-01

    Climate evolution, with the foreseen increase of temperature and frequency of drought events during the summer, could cause significant changes in the availability of water resources specially in the Mediterranean region. European countries need to encourage sustainable agriculture practices, reducing inputs, especially of water, and minimizing any negative impact on crop quantity and quality. Olive is an important crop in the Mediterranean region that has traditionally been cultivated with no irrigation and is known to attain acceptable production under dry farming. Therefore this crop will not compete for foreseen reduced water resources. However, a good quantitative knowledge must be available about effects of reduced precipitation and water availability on yield. Yield response functions, coupled with indicators of soil water availability, provide a quantitative description of the cultivar- specific behavior in relation to hydrological conditions. Yield response functions of 11 olive cultivars, typical of Mediterranean environment, were determined using experimental data (unpublished or reported in scientific literature). The yield was expressed as relative yield (Yr); the soil water availability was described by means of different indicators: relative soil water deficit (RSWD), relative evapotranspiration (RED) and transpiration deficit (RTD). Crops can respond nonlinearly to changes in their growing conditions and exhibit threshold responses, so for the yield functions of each olive cultivar both linear regression and threshold-slope models were considered to evaluate the best fit. The level of relative yield attained in rain-fed conditions was identified and defined as the acceptable yield level (Yrrainfed). The value of the indicator (RSWD, RED and RTD) corresponding to Yrrainfed was determined for each cultivar and indicated as the critical value of water availability. The error in the determination of the critical value was estimated. By means of a

  7. Estimating plant available water for general crop simulations in ALMANAC/APEX/EPIC/SWAT

    USDA-ARS?s Scientific Manuscript database

    Process-based simulation models ALMANAC/APEX/EPIC/SWAT contain generalized plant growth subroutines to predict biomass and crop yield. Environmental constraints typically restrict plant growth and yield. Water stress is often an important limiting factor; it is calculated as the sum of water use f...

  8. Iron availability limits the ocean nitrogen inventory stabilizing feedbacks between marine denitrification and nitrogen fixation

    NASA Astrophysics Data System (ADS)

    Moore, J. Keith; Doney, Scott C.

    2007-06-01

    Recent upward revisions in key sink/source terms for fixed nitrogen (N) in the oceans imply a short residence time and strong negative feedbacks involving denitrification and N fixation to prevent large swings in the ocean N inventory over timescales of a few centuries. We tested the strength of these feedbacks in a global biogeochemical elemental cycling (BEC) ocean model that includes water column denitrification and an explicit N fixing phytoplankton group. In the northern Indian Ocean and over longer timescales in the tropical Atlantic, we find strong stabilizing feedbacks that minimize changes in marine N inventory over timescales of ˜30-200 years. In these regions high atmospheric dust/iron inputs lead to phosphorus limitation of diazotrophs, and thus a tight link between N fixation and surface water N/P ratios. Maintenance of the oxygen minimum zones in these basins depends on N fixation driven export. The stabilizing feedbacks in other regions are significant but weaker owing to iron limitation of the diazotrophs. Thus Fe limitation appears to restrict the ability of N fixation to compensate for changes in denitrification in the current climate, perhaps leading the oceans to lose fixed N. We suggest that iron is the ultimate limiting nutrient leading to nitrogen being the proximate limiting nutrient over wide regions today. Iron stress was at least partially alleviated during more dusty, glacial times, leading to a higher marine N inventory, increased export production, and perhaps widespread phosphorus limitation of the phytoplankton community. The increased efficiency of the biological pump would have contributed to the glacial drawdown in atmospheric CO2.

  9. 40 CFR 439.14 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of best available technology economically achievable (BAT). 439.14 Section 439.14 Protection of... application of best available technology economically achievable (BAT). (a) Except as provided in 40 CFR 125... effluent limitations representing the application of BAT: Effluent Limitations (BAT) Regulated parameter...

  10. 40 CFR 442.43 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Effluent limitations attainable by the application of best available technology economically achievable (BAT). [Reserved] 442.43 Section 442.43... limitations attainable by the application of best available technology economically achievable (BAT...

  11. 40 CFR 442.43 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Effluent limitations attainable by the application of best available technology economically achievable (BAT). [Reserved] 442.43 Section 442.43... limitations attainable by the application of best available technology economically achievable (BAT...

  12. 40 CFR 439.14 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of best available technology economically achievable (BAT). 439.14 Section 439.14 Protection of... application of best available technology economically achievable (BAT). (a) Except as provided in 40 CFR 125... effluent limitations representing the application of BAT: Effluent Limitations (BAT) Regulated parameter...

  13. Soil water availability and evaporative demand affect seasonal growth dynamics and use of stored water in co-occurring saplings and mature conifers under drought.

    PubMed

    Oberhuber, Walter

    2017-04-01

    High-resolution time series of stem radius variations (SRVs) record fluctuations in tree water status and temporal dynamics of radial growth. The focus of this study was to evaluate the influence of tree size (i.e., saplings vs. mature trees) and soil water availability on SRVs. Dendrometers were installed on Pinus sylvestris at an open xeric site and on Picea abies at a dry-mesic site, and the SRVs of co-occurring saplings and mature trees were analyzed during two consecutive years. The results revealed that irrespective of tree size, radial growth in P. sylvestris occurred in April-May, whereas the main growing period of P. abies was April-June (saplings) and May-June (mature trees). Linear relationships between growth-detrended SRVs (SSRVs) of mature trees vs. saplings and climate-SSRV relationships revealed greater use of water reserves by mature P. abies compared with saplings. This suggests that the strikingly depressed growth of saplings compared with mature P. abies was caused by source limitation, i.e., restricted photosynthesis beneath the dense canopy. In contrast, a tree size effect on the annual increment, SSRV, and climate-SSRV relationships was less obvious in P. sylvestris , indicating comparable water status in mature trees and saplings under an open canopy. The results of this study provided evidence that water availability and a canopy atmosphere can explain differences in temporal dynamics of radial growth and use of stem water reserves among mature trees and saplings.

  14. Influencing factors for household water quality improvement in reducing diarrhoea in resource-limited areas.

    PubMed

    Zin, Thant; Mudin, Kamarudin D; Myint, Than; Naing, Daw K S; Sein, Tracy; Shamsul, B S

    2013-01-01

    Water and sanitation are major public health issues exacerbated by rapid population growth, limited resources, disasters and environmental depletion. This study was undertaken to study the influencing factors for household water quality improvement for reducing diarrhoea in resource-limited areas. Data were collected from articles and reviews from relevant randomized controlled trials, new articles, systematic reviews and meta-analyses from PubMed, World Health Organization (WHO), United Nations Children's Fund (UNICEF) and WELL Resource Centre For Water, Sanitation And Environmental Health. Water quality on diarrhoea prevention could be affected by contamination during storage, collection and even at point-of-use. Point-of-use water treatment (household-based) is the most cost-effective method for prevention of diarrhoea. Chemical disinfection, filtration, thermal disinfection, solar disinfection and flocculation and disinfection are five most promising household water treatment methodologies for resource-limited areas. Promoting household water treatment is most essential for preventing diarrhoeal disease. In addition, the water should be of acceptable taste, appropriate for emergency and non-emergency use.

  15. An Assessment of Water Demand and Availability to meet Construction and Operational Needs for Large Utility-Scale Solar Projects in the Southwestern United States

    NASA Astrophysics Data System (ADS)

    Klise, G. T.; Tidwell, V. C.; Macknick, J.; Reno, M. D.; Moreland, B. D.; Zemlick, K. M.

    2013-12-01

    In the Southwestern United States, there are many large utility-scale solar photovoltaic (PV) and concentrating solar power (CSP) facilities currently in operation, with even more under construction and planned for future development. These are locations with high solar insolation and access to large metropolitan areas and existing grid infrastructure. The Bureau of Land Management, under a reasonably foreseeable development scenario, projects a total of almost 32 GW of installed utility-scale solar project capacity in the Southwest by 2030. To determine the potential impacts to water resources and the potential limitations water resources may have on development, we utilized methods outlined by the Bureau of Land Management (BLM) to determine potential water use in designated solar energy zones (SEZs) for construction and operations & maintenance (O&M), which is then evaluated according to water availability in six Southwestern states. Our results indicate that PV facilities overall use less water, however water for construction is high compared to lifetime operational water needs. There is a transition underway from wet cooled to dry cooled CSP facilities and larger PV facilities due to water use concerns, though some water is still necessary for construction, operations, and maintenance. Overall, ten watersheds, 9 in California, and one in New Mexico were identified as being of particular concern because of limited water availability. Understanding the location of potentially available water sources can help the solar industry determine locations that minimize impacts to existing water resources, and help understand potential costs when utilizing non-potable water sources or purchasing existing appropriated water. 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

  16. Evaluation of Ground-Water Resources From Available Data, 1992, East Molokai Volcano, Hawaii

    USGS Publications Warehouse

    Anthony, Stephen S.

    1995-01-01

    Available ground-water data for East Molokai Volcano consist of well-construction information and records of ground-water pumpage, water levels, and chloride concentrations. Ground-water pumpage records are available for ten wells. Seventeen long-term (10 years or more) records of water-level and/or chloride concentration are available for eleven wells; however, only seven of these records are for observation wells. None of the available data show significant long-term changes in water level or chloride concentration; however, short-term changes due to variations in the quantity of water pumped, and rainfall are evident. Evaluation of the historical distribution and rates of ground-water pumpage, and variations in water levels and chloride concentrations is constrained by the scanty distribution of spatial and temporal data. Data show a range in water levels from greater than 850 feet above mean sea level in wells located in the windward valley of Waikolu to about 10 feet in wells located east of Kualapuu to 1 to 5 feet in the wells located along the south shore of East Molokai Volcano. An accurate contour map of water levels and chloride concentrations at the surface of the basal-water body cannot be constructed for any time period. Because water-level and chloride data are not collected at regular time intervals, many long-term records are incomplete. Information on the variation in chloride concentration with depth through the freshwater part of the basal-water body and into the zone of transition between freshwater and saltwater does not exist.

  17. 40 CFR 439.34 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of best available technology economically achievable (BAT). 439.34 Section 439.34 Protection of... attainable by the application of best available technology economically achievable (BAT). Except as provided... following effluent limitations representing the application of BAT: (a) The limitations are the same as...

  18. 40 CFR 439.24 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of best available technology economically achievable (BAT). 439.24 Section 439.24 Protection of... by the application of best available technology economically achievable (BAT). Except as provided in... following effluent limitations representing the application of BAT: Limitations for COD are the same as the...

  19. 40 CFR 439.24 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of best available technology economically achievable (BAT). 439.24 Section 439.24 Protection of... by the application of best available technology economically achievable (BAT). Except as provided in... following effluent limitations representing the application of BAT: Limitations for COD are the same as the...

  20. 40 CFR 439.34 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of best available technology economically achievable (BAT). 439.34 Section 439.34 Protection of... attainable by the application of best available technology economically achievable (BAT). Except as provided... following effluent limitations representing the application of BAT: (a) The limitations are the same as...

  1. 40 CFR 439.34 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of best available technology economically achievable (BAT). 439.34 Section 439.34 Protection of... attainable by the application of best available technology economically achievable (BAT). Except as provided... following effluent limitations representing the application of BAT: (a) The limitations are the same as...

  2. 40 CFR 439.44 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of best available technology economically achievable (BAT). 439.44 Section 439.44 Protection of... by the application of best available technology economically achievable (BAT). Except as provided in... following effluent limitations representing the application of BAT: The limitations for COD are the same as...

  3. 40 CFR 439.44 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of best available technology economically achievable (BAT). 439.44 Section 439.44 Protection of... by the application of best available technology economically achievable (BAT). Except as provided in... following effluent limitations representing the application of BAT: The limitations for COD are the same as...

  4. 40 CFR 439.24 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of best available technology economically achievable (BAT). 439.24 Section 439.24 Protection of... by the application of best available technology economically achievable (BAT). Except as provided in... following effluent limitations representing the application of BAT: Limitations for COD are the same as the...

  5. Extreme value theory applied to the definition of bathing water quality discounting limits.

    PubMed

    Haggarty, R A; Ferguson, C A; Scott, E M; Iroegbu, C; Stidson, R

    2010-02-01

    The European Community Bathing Water Directive (European Parliament, 2006) set compliance standards for bathing waters across Europe, with minimum standards for microbiological indicators to be attained at all locations by 2015. The Directive allows up to 15% of samples affected by short-term pollution episodes to be disregarded from the figures used to classify bathing waters, provided certain management criteria have been met, including informing the public of short-term water pollution episodes. Therefore, a scientifically justifiable discounting limit is required which could be used as a management tool to determine the samples that should be removed. This paper investigates different methods of obtaining discounting limits, focusing in particular on extreme value methodology applied to data from Scottish bathing waters. Return level based limits derived from threshold models applied at a site-specific level improved the percentage of sites which met at least the minimum required standard. This approach provides a method of obtaining limits which identify the samples that should be removed from compliance calculations, although care has to be taken in terms of the quantity of data which is removed. (c) 2009 Elsevier Ltd. All rights reserved.

  6. Food availability at birth limited reproductive success in historical humans.

    PubMed

    Rickard, Ian J; Holopainen, Jari; Helama, Samuli; Helle, Samuli; Russell, Andrew F; Lummaa, Virpi

    2010-12-01

    Environmental conditions in early life can profoundly affect individual development and have consequences for reproductive success. Limited food availability may be one of the reasons for this, but direct evidence linking variation in early-life nutrition to reproductive performance in adulthood in natural populations is sparse. We combined historical agricultural data with detailed demographic church records to investigate the effect of food availability around the time of birth on the reproductive success of 927 men and women born in 18th-century Finland. Our study population exhibits natural mortality and fertility rates typical of many preindustrial societies, and individuals experienced differing access to resources due to social stratification. We found that among both men and women born into landless families (i.e., with low access to resources), marital prospects, probability of reproduction, and offspring viability were all positively related to local crop yield during the birth year. Such effects were generally absent among those born into landowning families. Among landless individuals born when yields of the two main crops, rye and barley, were both below median, only 50% of adult males and 55% of adult females gained any reproductive success in their lifetime, whereas 97% and 95% of those born when both yields were above the median did so. Our results suggest that maternal investment in offspring in prenatal or early postnatal life may have profound implications for the evolutionary fitness of human offspring, particularly among those for which resources are more limiting. Our study adds support to the idea that early nutrition can limit reproductive success in natural animal populations, and provides the most direct evidence to date that this process applies to humans.

  7. Stay-green traits to improve wheat adaptation in well-watered and water-limited environments

    PubMed Central

    Christopher, John.T.; Christopher, Mandy J.; Borrell, Andrew K.; Fletcher, Susan; Chenu, Karine

    2016-01-01

    A stay-green phenotype enables crops to retain green leaves longer after anthesis compared with senescent types, potentially improving yield. Measuring the normalized difference vegetative index (NDVI) during the whole senescence period allows quantification of component stay-green traits contributing to a stay-green phenotype. These objective and standardized traits can be compared across genotypes and environments. Traits examined include maximum NDVI near anthesis (Nmax), senescence rate (SR), a trait integrating senescence (SGint), plus time from anthesis to onset (OnS), mid-point (MidS), and near completion (EndS) of senescence. The correlation between stay-green traits and yield was studied in eight contrasting environments ranging from well watered to severely water limited. Environments were each classified into one of the four major drought environment types (ETs) previously identified for the Australian wheat cropping system. SGint, OnS, and MidS tended to have higher values in higher yielding environments for a given genotype, as well as for higher yielding genotypes within a given environment. Correlation between specific stay-green traits and yield varied with ET. In the studied population, SGint, OnS, and MidS strongly correlated with yield in three of the four ETs which included well-watered environments (0.43–0.86), but less so in environments with only moderate water-stress after anthesis (−0.03 to 0.31). In contrast, Nmax was most highly correlated with yield under moderate post-anthesis water stress (0.31–0.43). Selection for particular stay-green traits, combinations of traits, and/or molecular markers associated with the traits could enhance genetic progress toward stay-green wheats with higher, more stable yield in both well-watered and water-limited conditions. PMID:27443279

  8. The role of reservoir storage in large-scale surface water availability analysis for Europe

    NASA Astrophysics Data System (ADS)

    Garrote, L. M.; Granados, A.; Martin-Carrasco, F.; Iglesias, A.

    2017-12-01

    A regional assessment of current and future water availability in Europe is presented in this study. The assessment was made using the Water Availability and Adaptation Policy Analysis (WAAPA) model. The model was built on the river network derived from the Hydro1K digital elevation maps, including all major river basins of Europe. Reservoir storage volume was taken from the World Register of Dams of ICOLD, including all dams with storage capacity over 5 hm3. Potential Water Availability is defined as the maximum amount of water that could be supplied at a certain point of the river network to satisfy a regular demand under pre-specified reliability requirements. Water availability is the combined result of hydrological processes, which determine streamflow in natural conditions, and human intervention, which determines the available hydraulic infrastructure to manage water and establishes water supply conditions through operating rules. The WAAPA algorithm estimates the maximum demand that can be supplied at every node of the river network accounting for the regulation capacity of reservoirs under different management scenarios. The model was run for a set of hydrologic scenarios taken from the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP), where the PCRGLOBWB hydrological model was forced with results from five global climate models. Model results allow the estimation of potential water stress by comparing water availability to projections of water abstractions along the river network under different management alternatives. The set of sensitivity analyses performed showed the effect of policy alternatives on water availability and highlighted the large uncertainties linked to hydrological and anthropological processes.

  9. 40 CFR 439.24 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of best available technology economically achievable (BAT). 439.24 Section 439.24 Protection of... application of best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30... limitations representing the application of BAT: Limitations for COD are the same as the corresponding...

  10. 40 CFR 439.24 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of best available technology economically achievable (BAT). 439.24 Section 439.24 Protection of... application of best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30... limitations representing the application of BAT: Limitations for COD are the same as the corresponding...

  11. Using the CAUSE Model to Understand Public Communication about Water Risks: Perspectives from Texas Groundwater District Officials on Drought and Availability.

    PubMed

    VanDyke, Matthew S; King, Andy J

    2017-12-05

    Public communication about drought and water availability risks poses challenges to a potentially disinterested public. Water management professionals, though, have a responsibility to work with the public to engage in communication about water and environmental risks. Because limited research in water management examines organizational communication practices and perceptions, insights into research and practice can be gained through investigation of current applications of these risk communication efforts. Guided by the CAUSE model, which explains common goals in communicating risk information to the public (e.g., creating Confidence, generating Awareness, enhancing Understanding, gaining Satisfaction, and motivating Enactment), semistructured interviews of professionals (N = 25) employed by Texas groundwater conservation districts were conducted. The interviews examined how CAUSE model considerations factor in to communication about drought and water availability risks. These data suggest that many work to build constituents' confidence in their districts. Although audiences and constituents living in drought-prone areas were reported as being engaged with water availability risks and solutions, many district officials noted constituents' lack of perceived risk and engagement. Some managers also indicated that public understanding was a secondary concern of their primary responsibilities and that the public often seemed apathetic about technical details related to water conservation risks. Overall, results suggest complicated dynamics between officials and the public regarding information access and motivation. The article also outlines extensions of the CAUSE model and implications for improving public communication about drought and water availability risks. © 2017 Society for Risk Analysis.

  12. Use of the Priestley-Taylor evaporation equation for soil water limited conditions in a small forest clearcut

    USGS Publications Warehouse

    Flint, A.L.; Childs, S.W.

    1991-01-01

    The Priestley-Taylor equation, a simplification of the Penman equation, was used to allow calculations of evapotranspiration under conditions where soil water supply limits evapotranspiration. The Priestley-Taylor coefficient, ??, was calculated to incorporate an exponential decrease in evapotranspiration as soil water content decreases. The method is appropriate for use when detailed meteorological measurements are not available. The data required to determine the parameter for the ?? coefficient are net radiation, soil heat flux, average air temperature, and soil water content. These values can be obtained from measurements or models. The dataset used in this report pertains to a partially vegetated clearcut forest site in southwest Oregon with soil depths ranging from 0.48 to 0.70 m and weathered bedrock below that. Evapotranspiration was estimated using the Bowen ratio method, and the calculated Priestley-Taylor coefficient was fitted to these estimates by nonlinear regression. The calculated Priestley-Taylor coefficient (?????) was found to be approximately 0.9 when the soil was near field capacity (0.225 cm3 cm-3). It was not until soil water content was less than 0.14 cm3 cm-3 that soil water supply limited evapotranspiration. The soil reached a final residual water content near 0.05 cm3 cm-3 at the end of the growing season. ?? 1991.

  13. Accuracy limit of rigid 3-point water models

    NASA Astrophysics Data System (ADS)

    Izadi, Saeed; Onufriev, Alexey V.

    2016-08-01

    Classical 3-point rigid water models are most widely used due to their computational efficiency. Recently, we introduced a new approach to constructing classical rigid water models [S. Izadi et al., J. Phys. Chem. Lett. 5, 3863 (2014)], which permits a virtually exhaustive search for globally optimal model parameters in the sub-space that is most relevant to the electrostatic properties of the water molecule in liquid phase. Here we apply the approach to develop a 3-point Optimal Point Charge (OPC3) water model. OPC3 is significantly more accurate than the commonly used water models of same class (TIP3P and SPCE) in reproducing a comprehensive set of liquid bulk properties, over a wide range of temperatures. Beyond bulk properties, we show that OPC3 predicts the intrinsic charge hydration asymmetry (CHA) of water — a characteristic dependence of hydration free energy on the sign of the solute charge — in very close agreement with experiment. Two other recent 3-point rigid water models, TIP3PFB and H2ODC, each developed by its own, completely different optimization method, approach the global accuracy optimum represented by OPC3 in both the parameter space and accuracy of bulk properties. Thus, we argue that an accuracy limit of practical 3-point rigid non-polarizable models has effectively been reached; remaining accuracy issues are discussed.

  14. Shallow water equations: viscous solutions and inviscid limit

    NASA Astrophysics Data System (ADS)

    Chen, Gui-Qiang; Perepelitsa, Mikhail

    2012-12-01

    We establish the inviscid limit of the viscous shallow water equations to the Saint-Venant system. For the viscous equations, the viscosity terms are more degenerate when the shallow water is close to the bottom, in comparison with the classical Navier-Stokes equations for barotropic gases; thus, the analysis in our earlier work for the classical Navier-Stokes equations does not apply directly, which require new estimates to deal with the additional degeneracy. We first introduce a notion of entropy solutions to the viscous shallow water equations and develop an approach to establish the global existence of such solutions and their uniform energy-type estimates with respect to the viscosity coefficient. These uniform estimates yield the existence of measure-valued solutions to the Saint-Venant system generated by the viscous solutions. Based on the uniform energy-type estimates and the features of the Saint-Venant system, we further establish that the entropy dissipation measures of the viscous solutions for weak entropy-entropy flux pairs, generated by compactly supported C 2 test-functions, are confined in a compact set in H -1, which yields that the measure-valued solutions are confined by the Tartar-Murat commutator relation. Then, the reduction theorem established in Chen and Perepelitsa [5] for the measure-valued solutions with unbounded support leads to the convergence of the viscous solutions to a finite-energy entropy solution of the Saint-Venant system with finite-energy initial data, which is relative with respect to the different end-states of the bottom topography of the shallow water at infinity. The analysis also applies to the inviscid limit problem for the Saint-Venant system in the presence of friction.

  15. Hydrologic modeling for monitoring water availability in Eastern and Southern Africa

    NASA Astrophysics Data System (ADS)

    McNally, A.; Harrison, L.; Shukla, S.; Pricope, N. G.; Peters-Lidard, C. D.

    2017-12-01

    Severe droughts in 2015, 2016 and 2017 in Ethiopia, Southern Africa, and Somalia have negatively impacted agriculture and municipal water supplies resulting in food and water insecurity. Information from remotely sensed data and field reports indicated that the Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation (FLDAS) accurately tracked both the anomalously low soil moisture, evapotranspiration and runoff conditions. This work presents efforts to more precisely monitor how the water balance responds to water availability deficits (i.e. drought) as estimated by the FLDAS with CHIRPS precipitation, MERRA-2 meteorological forcing and the Noah33 land surface model.Preliminary results indicate that FLDAS streamflow estimates are well correlated with observed streamflow where irrigation and other channel modifications are not present; FLDAS evapotranspiration (ET) is well correlated with ET from the Operational Simplified Surface Energy Balance model (SSEBop) in Eastern and Southern Africa. We then use these results to monitor availability, and explore trends in water supply and demand.

  16. Regional scaling of annual mean precipitation and water availability with global temperature change

    NASA Astrophysics Data System (ADS)

    Greve, Peter; Gudmundsson, Lukas; Seneviratne, Sonia I.

    2018-03-01

    Changes in regional water availability belong to the most crucial potential impacts of anthropogenic climate change, but are highly uncertain. It is thus of key importance for stakeholders to assess the possible implications of different global temperature thresholds on these quantities. Using a subset of climate model simulations from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), we derive here the sensitivity of regional changes in precipitation and in precipitation minus evapotranspiration to global temperature changes. The simulations span the full range of available emission scenarios, and the sensitivities are derived using a modified pattern scaling approach. The applied approach assumes linear relationships on global temperature changes while thoroughly addressing associated uncertainties via resampling methods. This allows us to assess the full distribution of the simulations in a probabilistic sense. Northern high-latitude regions display robust responses towards wetting, while subtropical regions display a tendency towards drying but with a large range of responses. Even though both internal variability and the scenario choice play an important role in the overall spread of the simulations, the uncertainty stemming from the climate model choice usually accounts for about half of the total uncertainty in most regions. We additionally assess the implications of limiting global mean temperature warming to values below (i) 2 K or (ii) 1.5 K (as stated within the 2015 Paris Agreement). We show that opting for the 1.5 K target might just slightly influence the mean response, but could substantially reduce the risk of experiencing extreme changes in regional water availability.

  17. Increasingly, Data Availability Limits Model Predictive Capacity: the Western Lake Erie Basin, a Case Study

    NASA Astrophysics Data System (ADS)

    Behrman, K. D.; Johnson, M. V. V.; Atwood, J. D.; Norfleet, M. L.

    2016-12-01

    Recent algal blooms in Western Lake Erie Basin (WLEB) have renewed scientific community's interest in developing process based models to better understand and predict the drivers of eutrophic conditions in the lake. At the same time, in order to prevent future blooms, farmers, local communities and policy makers are interested in developing spatially explicit nutrient and sediment management plans at various scales, from field to watershed. These interests have fueled several modeling exercises intended to locate "hotspots" in the basin where targeted adoption of additional agricultural conservation practices could provide the most benefit to water quality. The models have also been used to simulate various scenarios representing potential agricultural solutions. The Soil and Water Assessment Tool (SWAT) and its sister model, the Agricultural Policy Environmental eXtender (APEX), have been used to simulate hydrology of interacting land uses in thousands of scientific studies around the world. High performance computing allows SWAT and APEX users to continue to improve and refine the model specificity to make predictions at small-spatial scales. Consequently, data inputs and calibration/validation data are now becoming the limiting factor to model performance. Water quality data for the tributaries and rivers that flow through WLEB is spatially and temporally limited. Land management data, including conservation practice and nutrient management data, are not publicly available at fine spatial and temporal scales. Here we show the data uncertainties associated with modeling WLEB croplands at a relatively large spatial scale (HUC-4) using site management data from over 1,000 farms collected by the Conservation Effects Assessment Project (CEAP). The error associated with downscaling this data to the HUC-8 and HUC-12 scale is shown. Simulations of spatially explicit dynamics can be very informative, but care must be taken when policy decisions are made based on models

  18. Ground-water quality assessment of the central Oklahoma aquifer, Oklahoma - Analysis of available water-quality data through 1987

    USGS Publications Warehouse

    Parkhurst, David L.; Christenson, Scott C.; Schlottmann, Jamie L.

    1989-01-01

    Beginning in 1986, the Congress annually has appropriated funds for the U.S. Geological Survey to test and refine concepts for a National Water-Quality Assessment (NAWQA) Program. The long-term goals of a full-scale program would be to:Provide a nationally consistent description of current water-quality conditions for a large part of the Nation's surface- and ground-water resources;Define long-term trends (or lack of trends) in water quality; andIdentify, describe, and explain, as possible, the major factors that affect the observed water-quality conditions and trends.The results of the NAWQA Program will be made available to water managers, policy makers, and the public, and will provide an improved scientific basis for evaluating the effectiveness of water-quality management programs.At present (1988), the assessment program is in a pilot phase in seven project areas throughout the country that represent diverse hydrologic environments and water-quality conditions. The Central Oklahoma aquifer project is one of three pilot ground-water projects. One of the initial activities performed by each pilot project was to compile, screen, and interpret the large amount of water-quality data available within each study unit.The purpose of this report is to assess the water quality of the Central Oklahoma aquifer using the information available through 1987. The scope of the work includes compiling data from Federal, State, and local agencies; evaluating the suitability of the information for conducting a regional water-quality assessment; mapping regional variations in major-ion chemistry; calculating summary statistics of the available water-quality data; producing maps to show the location and number of samples that exceeded water-quality standards; and performing contingency-table analyses to determine the relation of geologic unit and depth to the occurrence of chemical constituents that exceed water-quality standards. This report provides an initial description of

  19. Ground-Water Availability Assessment for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    USGS Publications Warehouse

    ,

    2008-01-01

    The U.S. Geological Survey (USGS) is assessing the availability and use of the Nation's water resources to gain a clearer understanding of the status of our water resources and the land-use, water-use, and climatic trends that affect them. The goal of the National assessment is to improve our ability to forecast water availability for future economic and environmental uses. Assessments will be completed for regional aquifer systems across the Nation to help characterize how much water we have now, how water availability is changing, and how much water we can expect to have in the future (Reilly and others, 2008). Water availability is a function of many factors, including the quantity and quality of water, and the laws, regulations, economics, and environmental factors that control its use. The focus of the Columbia Plateau regional ground-water availability assessment is to improve fundamental knowledge of the ground-water balance of the region, including the flows, storage, and ground-water use by humans. An improved quantitative understanding of the region's water balance not only provides key information about water quantity, but also can serve as a fundamental basis for many analyses of water quality and ecosystem health.

  20. 40 CFR 439.34 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of best available technology economically achievable (BAT). 439.34 Section 439.34 Protection of... application of best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30... limitations representing the application of BAT: (a) The limitations are the same as specified in § 439.14(a...

  1. 40 CFR 439.34 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of best available technology economically achievable (BAT). 439.34 Section 439.34 Protection of... application of best available technology economically achievable (BAT). Except as provided in 40 CFR 125.30... limitations representing the application of BAT: (a) The limitations are the same as specified in § 439.14(a...

  2. Analytical steady-state solutions for water-limited cropping systems using saline irrigation water

    USDA-ARS?s Scientific Manuscript database

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mod...

  3. Ensuring water availability in Mekelle City, Northern Ethiopia: evaluation of the water supply sub-project

    NASA Astrophysics Data System (ADS)

    Oyedotun, Temitope D. Timothy

    2017-11-01

    The need and demand for water in the world are becoming acute with the growing population. This is mostly pressing in developing countries of which Mekelle City in Northern Ethiopia is not an exception. World Bank borehole-support sub-project was aimed at addressing this challenge. The evaluation of the intervention indicates that there is a significant increase in water supply in the city because of the sub-project. However, the increase in water supply has not been able to meet up with the already established and increasing demand. Coupled with this challenge are: the limited capacity of human capital and expertise that will ensure the proper management of borehole interventions; insufficient cost recovery for proper operation and maintenance of the projects; loss of land and farmlands and lack of compensations because of the projects which affect the livelihood.

  4. Habitat Selection by African Buffalo (Syncerus caffer) in Response to Landscape-Level Fluctuations in Water Availability on Two Temporal Scales

    PubMed Central

    Bennitt, Emily; Bonyongo, Mpaphi Casper; Harris, Stephen

    2014-01-01

    Seasonal fluctuations in water availability cause predictable changes in the profitability of habitats in tropical ecosystems, and animals evolve adaptive behavioural and spatial responses to these fluctuations. However, stochastic changes in the distribution and abundance of surface water between years can alter resource availability at a landscape scale, causing shifts in animal behaviour. In the Okavango Delta, Botswana, a flood-pulsed ecosystem, the volume of water entering the system doubled between 2008 and 2009, creating a sudden change in the landscape. We used African buffalo (Syncerus caffer) to test the hypotheses that seasonal habitat selection would be related to water availability, that increased floodwater levels would decrease forage abundance and affect habitat selection, and that this would decrease buffalo resting time, reduce reproductive success and decrease body condition. Buffalo selected contrasting seasonal habitats, using habitats far from permanent water during the rainy season and seasonally-flooded habitats close to permanent water during the early and late flood seasons. The 2009 water increase reduced forage availability in seasonally-flooded habitats, removing a resource buffer used by the buffalo during the late flood season, when resources were most limited. In response, buffalo used drier habitats in 2009, although there was no significant change in the time spent moving or resting, or daily distance moved. While their reproductive success decreased in 2009, body condition increased. A protracted period of high water levels could prove detrimental to herbivores, especially to smaller-bodied species that require high quality forage. Stochastic annual fluctuations in water levels, predicted to increase as a result of anthropogenically-induced climate change, are likely to have substantial impacts on the functioning of water-driven tropical ecosystems, affecting environmental conditions within protected areas. Buffer zones around

  5. Habitat selection by African buffalo (Syncerus caffer) in response to landscape-level fluctuations in water availability on two temporal scales.

    PubMed

    Bennitt, Emily; Bonyongo, Mpaphi Casper; Harris, Stephen

    2014-01-01

    Seasonal fluctuations in water availability cause predictable changes in the profitability of habitats in tropical ecosystems, and animals evolve adaptive behavioural and spatial responses to these fluctuations. However, stochastic changes in the distribution and abundance of surface water between years can alter resource availability at a landscape scale, causing shifts in animal behaviour. In the Okavango Delta, Botswana, a flood-pulsed ecosystem, the volume of water entering the system doubled between 2008 and 2009, creating a sudden change in the landscape. We used African buffalo (Syncerus caffer) to test the hypotheses that seasonal habitat selection would be related to water availability, that increased floodwater levels would decrease forage abundance and affect habitat selection, and that this would decrease buffalo resting time, reduce reproductive success and decrease body condition. Buffalo selected contrasting seasonal habitats, using habitats far from permanent water during the rainy season and seasonally-flooded habitats close to permanent water during the early and late flood seasons. The 2009 water increase reduced forage availability in seasonally-flooded habitats, removing a resource buffer used by the buffalo during the late flood season, when resources were most limited. In response, buffalo used drier habitats in 2009, although there was no significant change in the time spent moving or resting, or daily distance moved. While their reproductive success decreased in 2009, body condition increased. A protracted period of high water levels could prove detrimental to herbivores, especially to smaller-bodied species that require high quality forage. Stochastic annual fluctuations in water levels, predicted to increase as a result of anthropogenically-induced climate change, are likely to have substantial impacts on the functioning of water-driven tropical ecosystems, affecting environmental conditions within protected areas. Buffer zones around

  6. Glycerol enhances fungal germination at the water-activity limit for life.

    PubMed

    Stevenson, Andrew; Hamill, Philip G; Medina, Ángel; Kminek, Gerhard; Rummel, John D; Dijksterhuis, Jan; Timson, David J; Magan, Naresh; Leong, Su-Lin L; Hallsworth, John E

    2017-03-01

    For the most-extreme fungal xerophiles, metabolic activity and cell division typically halts between 0.700 and 0.640 water activity (approximately 70.0-64.0% relative humidity). Here, we investigate whether glycerol can enhance xerophile germination under acute water-activity regimes, using an experimental system which represents the biophysical limit of Earth's biosphere. Spores from a variety of species, including Aspergillus penicillioides, Eurotium halophilicum, Xerochrysium xerophilum (formerly Chrysosporium xerophilum) and Xeromyces bisporus, were produced by cultures growing on media supplemented with glycerol (and contained up to 189 mg glycerol g dry spores -1 ). The ability of these spores to germinate, and the kinetics of germination, were then determined on a range of media designed to recreate stresses experienced in microbial habitats or anthropogenic systems (with water-activities from 0.765 to 0.575). For A. penicillioides, Eurotium amstelodami, E. halophilicum, X. xerophilum and X. bisporus, germination occurred at lower water-activities than previously recorded (0.640, 0.685, 0.651, 0.664 and 0.637 respectively). In addition, the kinetics of germination at low water-activities were substantially faster than those reported previously. Extrapolations indicated theoretical water-activity minima below these values; as low as 0.570 for A. penicillioides and X. bisporus. Glycerol is present at high concentrations (up to molar levels) in many types of microbial habitat. We discuss the likely role of glycerol in expanding the water-activity limit for microbial cell function in relation to temporal constraints and location of the microbial cell or habitat. The findings reported here have also critical implications for understanding the extremes of Earth's biosphere; for understanding the potency of disease-causing microorganisms; and in biotechnologies that operate at the limits of microbial function. © 2016 The Authors. Environmental Microbiology

  7. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... limitations reflecting the best available technology economically achievable (BAT). Except as provided in 40... the best available technology economically achievable (BAT). (a) Beginning no later than August 1...

  8. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... Effluent limitations reflecting the best available technology economically achievable (BAT). Except as... application of the best available technology economically achievable (BAT). (a) Beginning no later than August...

  9. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... Effluent limitations reflecting the best available technology economically achievable (BAT). Except as... application of the best available technology economically achievable (BAT). (a) Beginning no later than August...

  10. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... limitations reflecting the best available technology economically achievable (BAT). Except as provided in 40... the best available technology economically achievable (BAT). (a) Beginning no later than August 1...

  11. 40 CFR 450.22 - Effluent limitations reflecting the best available technology economically achievable (BAT).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... best available technology economically achievable (BAT). 450.22 Section 450.22 Protection of... Effluent limitations reflecting the best available technology economically achievable (BAT). Except as... application of the best available technology economically achievable (BAT). (a) Beginning no later than August...

  12. Arbuscular Mycorrhiza Alleviates Restrictions to Substrate Water Flow and Delays Transpiration Limitation to Stronger Drought in Tomato.

    PubMed

    Bitterlich, Michael; Sandmann, Martin; Graefe, Jan

    2018-01-01

    Arbuscular mycorrhizal fungi (AMF) proliferate in soil pores, on the surface of soil particles and affect soil structure. Although modifications in substrate moisture retention depend on structure and could influence plant water extraction, mycorrhizal impacts on water retention and hydraulic conductivity were rarely quantified. Hence, we asked whether inoculation with AMF affects substrate water retention, water transport properties and at which drought intensity those factors become limiting for plant transpiration. Solanum lycopersicum plants were set up in the glasshouse, inoculated or not with Funneliformis mosseae , and grown for 35 days under ample water supply. After mycorrhizal establishment, we harvested three sets of plants, one before (36 days after inoculation) and the second (day 42) and third (day 47) within a sequential drying episode. Sampling cores were introduced into pots before planting. After harvest, moisture retention and substrate conductivity properties were assessed and water retention and hydraulic conductivity models were fitted. A root water uptake model was adopted in order to identify the critical substrate moisture that induces soil derived transpiration limitation. Neither substrate porosity nor saturated water contents were affected by inoculation, but both declined after substrates dried. Drying also caused a decline in pot water capacity and hydraulic conductivity. Plant available water contents under wet (pF 1.8-4.2) and dry (pF 2.5-4.2) conditions increased in mycorrhizal substrates and were conserved after drying. Substrate hydraulic conductivity was higher in mycorrhizal pots before and during drought exposure. After withholding water from pots, higher substrate drying rates and lower substrate water potentials were found in mycorrhizal substrates. Mycorrhiza neither affected leaf area nor root weight or length. Consistently with higher substrate drying rates, AMF restored the plant hydraulic status, and increased plant

  13. Arbuscular Mycorrhiza Alleviates Restrictions to Substrate Water Flow and Delays Transpiration Limitation to Stronger Drought in Tomato

    PubMed Central

    Bitterlich, Michael; Sandmann, Martin; Graefe, Jan

    2018-01-01

    Arbuscular mycorrhizal fungi (AMF) proliferate in soil pores, on the surface of soil particles and affect soil structure. Although modifications in substrate moisture retention depend on structure and could influence plant water extraction, mycorrhizal impacts on water retention and hydraulic conductivity were rarely quantified. Hence, we asked whether inoculation with AMF affects substrate water retention, water transport properties and at which drought intensity those factors become limiting for plant transpiration. Solanum lycopersicum plants were set up in the glasshouse, inoculated or not with Funneliformis mosseae, and grown for 35 days under ample water supply. After mycorrhizal establishment, we harvested three sets of plants, one before (36 days after inoculation) and the second (day 42) and third (day 47) within a sequential drying episode. Sampling cores were introduced into pots before planting. After harvest, moisture retention and substrate conductivity properties were assessed and water retention and hydraulic conductivity models were fitted. A root water uptake model was adopted in order to identify the critical substrate moisture that induces soil derived transpiration limitation. Neither substrate porosity nor saturated water contents were affected by inoculation, but both declined after substrates dried. Drying also caused a decline in pot water capacity and hydraulic conductivity. Plant available water contents under wet (pF 1.8–4.2) and dry (pF 2.5–4.2) conditions increased in mycorrhizal substrates and were conserved after drying. Substrate hydraulic conductivity was higher in mycorrhizal pots before and during drought exposure. After withholding water from pots, higher substrate drying rates and lower substrate water potentials were found in mycorrhizal substrates. Mycorrhiza neither affected leaf area nor root weight or length. Consistently with higher substrate drying rates, AMF restored the plant hydraulic status, and increased plant

  14. Challenges of reforestation in a water limited world under climate change

    NASA Astrophysics Data System (ADS)

    Mátyás, Csaba; Sun, Ge

    2014-05-01

    The debate on the ecological benefits of planted forests at the sensitive lower edge of the closed forest belt (at the "xeric limits") is still unresolved. Forests sequester atmospheric carbon dioxide, control water erosion and dust storms, reduce river sedimentation, and mitigate small floods. However, planting trees in areas previously predominantly occupied by grassland or agriculture can dramatically alter the energy and water balance at multiple scales. The forest/grassland transition zone is especially vulnerable to projected drastic temperature and precipitation shifts under future climate change and variability due to its high ecohydrological sensitivity. The study investigates some of the relevant aspects of the ecological and climatic role of plantation forests and potential impacts at the dryland edges of the temperate zone, using case studies from three countries/regions on three continents. We found that, contrary to popular expectations, the effect of forest cover on regional climate might be limited and the influence of reforestation on water resources might turn into negative. Planted forests generally reduce stream flow and lower groundwater table level because of higher water use than previous land cover types. Increased evaporation potential due to global warming and/or extreme drought events likely reduce areas that are appropriate for tree growth and forest establishment. Ecologically conscious forest policy on management, silviculture and reforestation planning requires the consideration of local hydrologic conditions, future climatic conditions, and also of non-forest alternatives of land use. Keywords: drylands, xeric limits, trailing limits, ecohydrology, climate forcing, land use change, forest policy

  15. Water quality, isoscapes and stoichioscapes of seagrasses indicate general P limitation and unique N cycling in shallow water benthos of Bermuda

    NASA Astrophysics Data System (ADS)

    Fourqurean, J. W.; Manuel, S. A.; Coates, K. A.; Kenworthy, W. J.; Boyer, J. N.

    2015-07-01

    Striking spatial patterns in stable isotope ratios (isoscapes) and elemental ratios (stoichioscapes) of seagrass leaves and the water column nutrients indicate general P-limitation of both water column and benthic primary productivity on the Bermuda Platform, and they highlight the role of the Bermuda Islands as a source of N and P. We found consistent differences among the four seagrass species (Syringodium filiforme, Thalassia testudinum, Halodule sp. and Halophila decipiens) in the N, P, δ13C and δ15N of leaf tissues. The δ15N of seagrass leaves was especially variable, with values from -10.1 to 8.8‰, greatly expanding the reported range of values for all seagrass species globally. Spatial patterns from both the water column and the seagrass leaves indicated that P availability was higher near shore, and δ15N values suggest this was likely a result of human waste disposal. Spatially-contiguous areas of extremely depleted seagrass δ15N suggest unique N sources and cycling compared to other seagrass-dominated environments. Seagrass N : P values were not as far from the stoichiometric balance between N and P availability as in the water column, and there were no strong relationships between the water column N : P and the seagrass N : P. Such isoscapes and stoichioscapes provide valuable ecogeochemical tools to infer ecosystem processes as well as provide information that can inform food web and animal movement studies.

  16. Water quality, isoscapes and stoichioscapes of seagrasses indicate general P limitation and unique N cycling in shallow water benthos of Bermuda

    NASA Astrophysics Data System (ADS)

    Fourqurean, J. W.; Manuel, S. A.; Coates, K. A.; Kenworthy, W. J.; Boyer, J. N.

    2015-10-01

    Striking spatial patterns in stable isotope ratios (isoscapes) and elemental ratios (stoichioscapes) of seagrass leaves and the water column nutrients indicate general P-limitation of both water column and benthic primary productivity on the Bermuda Platform, and they highlight the role of the Bermuda Islands as a source of N and P. We found consistent differences among the four seagrass species (Syringodium filiforme, Thalassia testudinum, Halodule sp. and Halophila decipiens) in the N, P, δ13C and δ15N of leaf tissues. The δ15N of seagrass leaves was especially variable, with values from -10.1 to 8.8 ‰, greatly expanding the reported range of values for all seagrass species globally. Spatial patterns from both the water column and the seagrass leaves indicated that P availability was higher near shore, and δ15N values suggest this was likely a result of human waste disposal. Spatially contiguous areas of extremely depleted seagrass 15N suggest unique N sources and cycling compared to other seagrass-dominated environments. Seagrass N : P values were not as far from the stoichiometric balance between N and P availability as in the water column, and there were no strong relationships between the water column N : P and the seagrass N : P. Such isoscapes and stoichioscapes provide valuable ecogeochemical tools to infer ecosystem processes as well as provide information that can inform food web and animal movement studies.

  17. Contribution potential of glaciers to water availability in different climate regimes

    PubMed Central

    Kaser, Georg; Großhauser, Martin; Marzeion, Ben

    2010-01-01

    Although reliable figures are often missing, considerable detrimental changes due to shrinking glaciers are universally expected for water availability in river systems under the influence of ongoing global climate change. We estimate the contribution potential of seasonally delayed glacier melt water to total water availability in large river systems. We find that the seasonally delayed glacier contribution is largest where rivers enter seasonally arid regions and negligible in the lowlands of river basins governed by monsoon climates. By comparing monthly glacier melt contributions with population densities in different altitude bands within each river basin, we demonstrate that strong human dependence on glacier melt is not collocated with highest population densities in most basins. PMID:21059938

  18. On the New Concept of the Available Water Climatology and Its Application

    NASA Astrophysics Data System (ADS)

    Byun, H. R.; Kim, D. W.; Choi, K. S.; Deo, R. C.; Lee, S. M.; Park, C. K.; Kwon, S. H.; Kim, G. B.; Kwon, H. N.

    2014-12-01

    We propose a new concept of climatology called the Available Water Climate (AWC). Available water is 'the remained water usable in every moment' that is calculated regardless of any time intervals or the amounts of precipitation. With this concept, the Available Water Resources Index (AWRI) has been digitized following the earlier work of Byun and Lee (2002). The applicability of AWRI not only to the assessment and prediction of water related disasters but also to the academic researches has been tested. Resulted merits are as follows. Firstly, the threshold value of AWRI for the occurrence of all water related disasters like flood, drought, inundation landslide, and drought each region became clear, therefore the assessment and the prediction of them became much more precise than before. It became clear that the more extreme the AWRI value is, the severer the related disasters become. As example, all disasters caused by heavy rains, even though a small inundation, became predictable at the time step of heavy rain warning with the help of the Long-term remained water index(LWI). As another example, the drought intensity and its dates on start and end are defined with more reasonably and precisely than any other drought indexes with help of the Effective drought index (EDI) using sliding time scale. Secondly, the spatiotemporal distribution of water environment were digitized clearly and objectively using AWRI and new concepts of the Water Abundant Season (WAS) and the Little Water Season (LIWAS), their dates on start and end, and their strength were defined, which is very beneficial for agriculture, forestry, and all other water controls. Also, the differences of water environments among regions were clearly digitized and the improvement of the climate classification by Köppen etc. became possible. Thirdly, other merits will be found continuously afterwards.

  19. Cover crop biomass production and water use in the central great plains under varying water availability

    USDA-ARS?s Scientific Manuscript database

    The water-limited environment of the semi-arid central Great Plains may not have potential to produce enough cover crop biomass to generate benefits associated with cover crop use in more humid regions. There have been reports that cover crops grown in mixtures produce more biomass with greater wate...

  20. Evaluation of available data sources to prioritize parishes for arsenic monitoring and outreach related to private well drinking water.

    PubMed

    Katner, Adrienne; Lackovic, Michelle; Streva, Kate; Paul, Vanessa; Trachtman, William Clay

    2015-01-01

    The objective of this assessment was to identify and evaluate data sets for use in the surveillance of arsenic hazards and private well drinking water use in Louisiana. Features, strengths, and limitations of the data sets are described, and prioritization criteria are applied to identify areas in need of further monitoring or outreach. Recent efforts have been made by the Environmental Public Health Tracking Network to evaluate the quality of private well water data for the purpose of supporting state and national surveillance activities. Like most states, Louisiana does not collect or mandate reporting of private well water quality data. Therefore, responding to public concerns about private well water quality requires an identification and evaluation of existing data. Data evaluated include measures of arsenic in groundwater and soil, private well water use, and biomonitoring results. The Environmental Protection Agency's Safe Drinking Water Information System and the US Geological Survey's Water Use data set were the most informative, nationally available data sets for conducting private well water arsenic surveillance. Three priority parishes were identified on the basis of a selection criteria, although all parishes require more private well sampling data. While the data reviewed enabled preliminary identification of parishes in need of monitoring and outreach, data limitations (particularly, a lack of statewide well water quality data) prevent a comprehensive evaluation of well water arsenic hazards and private well water use. A large number of unregistered wells further impede risk determination. Reliance on existing data sources is necessary, but development of metadata documentation is essential to prevent data misinterpretation. Increased outreach and policies to promote or mandate private well testing and reporting are needed to enable a comprehensive private well water tracking system.

  1. Limit regimes of ice formation in turbulent supercooled water.

    PubMed

    De Santi, Francesca; Olla, Piero

    2017-10-01

    A study of ice formation in stationary turbulent conditions is carried out in various limit regimes of crystal growth, supercooling, and ice entrainment at the water surface. Analytical expressions for the temperature, salinity, and ice concentration mean profiles are provided, and the role of fluctuations in ice production is numerically quantified. Lower bounds on the ratio of sensible heat flux to latent heat flux to the atmosphere are derived and their dependence on key parameters such as salt rejection in freezing and ice entrainment in the water column is elucidated.

  2. 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.

  3. Comparing hydraulic properties of soil-less substrates with natural soils: a more detailed look at hydraulic properties and their impact on plant water availability

    NASA Astrophysics Data System (ADS)

    Crawford, L.; Rivera, L. D.; van Iersel, M.

    2013-12-01

    Moisture release curves are often used when assessing plant-water relationships in soil-less substrates. However, differences between natural soils and soilless substrates make traditional assumptions about plant available water potentially invalid. If soil-less substrates are supposed to be treated like natural soils; why do plants begin wilting at very low water potentials (-10 to -30 kPa) and there is anywhere between 20 to 40 % water left (on a volumetric basis) in the soil (Abad et al., 2005; Arguedas et al., 2006; Ristvey et al, 2008) . We hypothesize that the fault lies in the methods used and the assumption that water potential is the only limiting factor in water availability to plants. Hydraulic properties, including the relationships that exist between plant available water, water content, and hydraulic conductivity of soil-less substrates have traditionally been characterized using instrumentation such as pressure plates, hanging water columns, and tempe cells. These approaches typically take a months and only provide data on select segments of the soil moisture release curve, and in the case of pressure plates and hanging water columns hydraulic conductivity is ignored and not very well understood. Using the Wind/Schindler Evaporation method more detailed measurements of these hydraulic properties can be measured in a less than a week. A more detailed look at the hydraulic properties of soil-less substrates and how they compare with natural soils may give us more insight into soil-plant-water-relations and what limits availability of water to plants. Soil moisture release curves and hydraulic conductivity curves of different soil-less substrates were compared with curves from typical agriculture soils to give insight into how these properties compare. Results of the soil moisture release curves showed that some soil-less substrates had comparable moisture release curves to agricultural soils while others had bi-modal curves indicating gap-gradation in

  4. Ground water security and drought in Africa: linking availability, access, and demand.

    PubMed

    Calow, Roger C; Macdonald, Alan M; Nicol, Alan L; Robins, Nick S

    2010-01-01

    Drought in Africa has been extensively researched, particularly from meteorological, agricultural, and food security perspectives. However, the impact of drought on water security, particularly ground water dependent rural water supplies, has received much less attention. Policy responses have concentrated on food needs, and it has often been difficult to mobilize resources for water interventions, despite evidence that access to safe water is a serious and interrelated concern. Studies carried out in Ghana, Malawi, South Africa, and Ethiopia highlight how rural livelihoods are affected by seasonal stress and longer-term drought. Declining access to food and water is a common and interrelated problem. Although ground water plays a vital role in buffering the effects of rainfall variability, water shortages and difficulties in accessing water that is available can affect domestic and productive water uses, with knock-on effects on food consumption and production. Total depletion of available ground water resources is rarely the main concern. A more common scenario is a spiral of water insecurity as shallow water sources fail, additional demands are put on remaining sources, and mechanical failures increase. These problems can be planned for within normal development programs. Water security mapping can help identify vulnerable areas, and changes to monitoring systems can ensure early detection of problems. Above all, increasing the coverage of ground water-based rural water supplies, and ensuring that the design and siting of water points is informed by an understanding of hydrogeological conditions and user demand, can significantly increase the resilience of rural communities to climate variability.

  5. Identification of glacial melt water runoff in a karstic environment and its implication for present and future water availability

    NASA Astrophysics Data System (ADS)

    Finger, D.; Hugentobler, A.; Huss, M.; Voinesco, A.; Wernli, H.; Fischer, D.; Weber, E.; Jeannin, P.-Y.; Kauzlaric, M.; Wirz, A.; Vennemann, T.; Hüsler, F.; Schädler, B.; Weingartner, R.

    2013-03-01

    Glaciers all over the world are expected to continue to retreat due to the global warming throughout the 21st century. Consequently, future seasonal water availability might become scarce once glacier areas have declined below a certain threshold affecting future water management strategies. Particular attention should be paid to glaciers located in a karstic environment, as parts of the melt water can be drained by souterrain karst systems. In this study tracer experiments, karst modeling and glacier melt modeling are combined in order to identify flow paths in a high alpine, glacierized, karstic environment (Glacier de la Plaine Morte, Switzerland) and to investigate current and predict future downstream water availability. Flow paths through the karst underground were determined with natural and fluorescent tracers. Subsequently, tracer results and geologic information were assembled in a karst model. Finally, glacier melt projections driven with a climate scenario were performed to discuss future water availability in the area surrounding the glacier. The results suggest that during late summer glacier melt water is rapidly drained through well-developed channels at the glacier bottom to the north of the glacier, while during low flow season melt water enters into the karst and is drained to the south. Climate change projections reveal that by the end of the century glacier melt will be significantly reduced in the summer, jeopardizing water availability in glacier-fed karst springs.

  6. Ground-water availability in part of the Borough of Carroll Valley, Adams County, Pennsylvania, and the establishment of a drought-monitor well

    USGS Publications Warehouse

    Low, Dennis J.; Conger, Randall W.

    2002-01-01

    Continued population growth in the Borough of Carroll Valley (Borough) coupled with the drought of 2001 have increased the demand for ground water in the Borough. This demand has led Borough officials to undertake an effort to evaluate the capability of the crystalline-bedrock aquifers to meet future, projected growth and to establish a drought-monitor well within and for the use of the Borough. As part of this effort, this report summarizes ground-water data available from selected sections within the Borough and provides geohydrologic information needed to evaluate ground-water availability and recharge sources within part of the Borough. The availability of ground water in the Borough is limited by the physical characteristics of the underlying bedrock, and its upland topographic setting. The crystalline rocks (metabasalt, metarhyolite, greenstone schist) that underlie most of the study area are among the lowest yielding aquifers in the Commonwealth. More than 25 percent of the wells drilled in the metabasalt, the largest bedrock aquifer in the study area, have driller reported yields less than 1.25 gallons per minute. Driller reports indicate also that water-producing zones are shallow and few in number. In general, 50 percent of the water-producing zones reported by drillers are penetrated at depths of 200 feet or less and 90 percent at depths of 370 feet or less. Borehole geophysical data indicate that most of the water-producing zones are at lithologic contacts, but such contacts are penetrated infrequently and commonly do not intersect areas of ground-water recharge. Single-well aquifer tests and slug tests indicate that the bedrock aquifers also do not readily transmit large amounts of water. The median hydraulic conductivity and transmissivity of the bedrock aquifers are 0.01 foot per dayand 2.75 feet squared per day, respectively. The crystalline and siliciclastic (Weverton and Loudoun Formations) bedrock aquifers are moderately to highly resistant to

  7. Understanding surface-water availability in the Central Valley as a means to projecting future groundwater storage with climate variability

    NASA Astrophysics Data System (ADS)

    Goodrich, J. P.; Cayan, D. R.

    2017-12-01

    California's Central Valley (CV) relies heavily on diverted surface water and groundwater pumping to supply irrigated agriculture. However, understanding the spatiotemporal character of water availability in the CV is difficult because of the number of individual farms and local, state, and federal agencies involved in using and managing water. Here we use the Central Valley Hydrologic Model (CVHM), developed by the USGS, to understand the relationships between climatic variability, surface water inputs, and resulting groundwater use over the historical period 1970-2013. We analyzed monthly surface water diversion data from >500 CV locations. Principle components analyses were applied to drivers constructed from meteorological data, surface reservoir storage, ET, land use cover, and upstream inflows, to feed multiple regressions and identify factors most important in predicting surface water diversions. Two thirds of the diversion locations ( 80% of total diverted water) can be predicted to within 15%. Along with monthly inputs, representations of cumulative precipitation over the previous 3 to 36 months can explain an additional 10% of variance, depending on location, compared to results that excluded this information. Diversions in the southern CV are highly sensitive to inter-annual variability in precipitation (R2 = 0.8), whereby more surface water is used during wet years. Until recently, this was not the case in the northern and mid-CV, where diversions were relatively constant annually, suggesting relative insensitivity to drought. In contrast, this has important implications for drought response in southern regions (eg. Tulare Basin) where extended dry conditions can severely limit surface water supplies and lead to excess groundwater pumping, storage loss, and subsidence. In addition to fueling our understanding of spatiotemporal variability in diversions, our ability to predict these water balance components allows us to update CVHM predictions before

  8. 40 CFR 432.93 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.93 Section 432.93 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... must achieve the following effluent limitations representing the application of BAT: (a) Facilities...

  9. 40 CFR 432.103 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.103 Section 432.103 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: Effluent Limitations [BAT...

  10. 40 CFR 432.93 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.93 Section 432.93 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... must achieve the following effluent limitations representing the application of BAT: (a) Facilities...

  11. 40 CFR 432.123 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.123 Section 432.123 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  12. 40 CFR 432.103 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.103 Section 432.103 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: Effluent Limitations [BAT...

  13. 40 CFR 432.103 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.103 Section 432.103 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: Effluent Limitations [BAT...

  14. 40 CFR 432.123 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.123 Section 432.123 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  15. 40 CFR 432.93 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.93 Section 432.93 Protection... limitations attainable by the application of the best available technology economically achievable (BAT... must achieve the following effluent limitations representing the application of BAT: (a) Facilities...

  16. Water availability change in central Belgium for the late 21st century

    NASA Astrophysics Data System (ADS)

    Tabari, Hossein; Taye, Meron Teferi; Willems, Patrick

    2015-08-01

    We investigate the potential impact of climate change on water availability in central Belgium. Two water balance components being precipitation and potential evapotranspiration are initially projected for the late 21st century (2071-2100) based on 30 Coupled Models Intercomparison Project phase 5 (CMIP5) models relative to a baseline period of 1961-1990, assuming forcing by four representative concentration pathway emission scenarios (RCP2.6, RCP4.5, RCP6.0, RCP8.5). The future available water is then estimated as the difference between precipitation and potential evapotranspiration projections. The number of wet days and mean monthly precipitation for summer season is projected to decrease in most of the scenarios, while the projections show an increase in those variables for the winter months. Potential evapotranspiration is expected to increase during both winter and summer seasons. The results show a decrease in water availability for summer and an increase for winter, suggesting drier summers and wetter winters for the late 21st century in central Belgium.

  17. 40 CFR 437.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 437.13 Section 437.13 Protection... attainable by the application of the best available technology economically achievable (BAT). (a) Except as... must achieve the following effluent limitations representing the application of BAT: Limitations for...

  18. 40 CFR 437.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 437.13 Section 437.13 Protection... attainable by the application of the best available technology economically achievable (BAT). (a) Except as... must achieve the following effluent limitations representing the application of BAT: Limitations for...

  19. 40 CFR 437.23 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 437.23 Section 437.23 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... must achieve the following effluent limitations by the application of BAT: Limitations for arsenic...

  20. 40 CFR 451.22 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 451.22 Section 451.22 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: The limitations are the same...

  1. 40 CFR 432.103 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.103 Section 432.103 Protection... application of the best available technology economically achievable (BAT). Except as provided by 40 CFR 125... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  2. 40 CFR 451.22 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 451.22 Section 451.22 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: The limitations are the same...

  3. 40 CFR 437.23 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 437.23 Section 437.23 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... must achieve the following effluent limitations by the application of BAT: Limitations for arsenic...

  4. 40 CFR 432.103 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.103 Section 432.103 Protection... application of the best available technology economically achievable (BAT). Except as provided by 40 CFR 125... effluent limitations representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter...

  5. Global monthly water scarcity: blue water footprints versus blue water availability.

    PubMed

    Hoekstra, Arjen Y; Mekonnen, Mesfin M; Chapagain, Ashok K; Mathews, Ruth E; Richter, Brian D

    2012-01-01

    Freshwater scarcity is a growing concern, placing considerable importance on the accuracy of indicators used to characterize and map water scarcity worldwide. We improve upon past efforts by using estimates of blue water footprints (consumptive use of ground- and surface water flows) rather than water withdrawals, accounting for the flows needed to sustain critical ecological functions and by considering monthly rather than annual values. We analyzed 405 river basins for the period 1996-2005. In 201 basins with 2.67 billion inhabitants there was severe water scarcity during at least one month of the year. The ecological and economic consequences of increasing degrees of water scarcity--as evidenced by the Rio Grande (Rio Bravo), Indus, and Murray-Darling River Basins--can include complete desiccation during dry seasons, decimation of aquatic biodiversity, and substantial economic disruption.

  6. Water-quality assessment of the Trinity River Basin, Texas - Analysis of available information on nutrients and suspended sediment, 1974-91

    USGS Publications Warehouse

    Van Metre, Peter C.; Reutter, David C.

    1995-01-01

    Only limited suspended-sediment data were available. Four sites had daily sediment-discharge records for three or more water years (October 1 to September 30) between 1974 and 1985. An additional three sites had periodic measurements of suspended-sediment concentrations. There are differences in concentrations and yields among sites; however, the limited amount of data precludes developing statistical or cause-and-effect relations with environmental factors such as land use, soil, and geology. Data are sufficient, and the relation is pronounced enough, to indicate trapping of suspended sediment by Livingston Reservoir.

  7. Availability of drinking water in US public school cafeterias.

    PubMed

    Hood, Nancy E; Turner, Lindsey; Colabianchi, Natalie; Chaloupka, Frank J; Johnston, Lloyd D

    2014-09-01

    This study examined the availability of free drinking water during lunchtime in US public schools, as required by federal legislation beginning in the 2011-2012 school year. Data were collected by mail-back surveys in nationally representative samples of US public elementary, middle, and high schools from 2009-2010 to 2011-2012. Overall, 86.4%, 87.4%, and 89.4% of students attended elementary, middle, and high schools, respectively, that met the drinking water requirement. Most students attended schools with existing cafeteria drinking fountains and about one fourth attended schools with water dispensers. In middle and high schools, respondents were asked to indicate whether drinking fountains were clean, and whether they were aware of any water-quality problems at the school. The vast majority of middle and high school students (92.6% and 90.4%, respectively) attended schools where the respondent perceived drinking fountains to be clean or very clean. Approximately one in four middle and high school students attended a school where the survey respondent indicated that there were water-quality issues affecting drinking fountains. Although most schools have implemented the requirement to provide free drinking water at lunchtime, additional work is needed to promote implementation at all schools. School nutrition staff at the district and school levels can play an important role in ensuring that schools implement the drinking water requirement, as well as promote education and behavior-change strategies to increase student consumption of water at school. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

  8. Global Monthly Water Scarcity: Blue Water Footprints versus Blue Water Availability

    PubMed Central

    Hoekstra, Arjen Y.; Mekonnen, Mesfin M.; Chapagain, Ashok K.; Mathews, Ruth E.; Richter, Brian D.

    2012-01-01

    Freshwater scarcity is a growing concern, placing considerable importance on the accuracy of indicators used to characterize and map water scarcity worldwide. We improve upon past efforts by using estimates of blue water footprints (consumptive use of ground- and surface water flows) rather than water withdrawals, accounting for the flows needed to sustain critical ecological functions and by considering monthly rather than annual values. We analyzed 405 river basins for the period 1996–2005. In 201 basins with 2.67 billion inhabitants there was severe water scarcity during at least one month of the year. The ecological and economic consequences of increasing degrees of water scarcity – as evidenced by the Rio Grande (Rio Bravo), Indus, and Murray-Darling River Basins – can include complete desiccation during dry seasons, decimation of aquatic biodiversity, and substantial economic disruption. PMID:22393438

  9. High sensitivity of northeastern broadleaf forest trees to water availability

    NASA Astrophysics Data System (ADS)

    Levesque, M.; Pederson, N.; Andreu-Hayles, L.

    2015-12-01

    Temperate deciduous forests of eastern US provide goods and services to millions of people and play a vital role in the terrestrial carbon and hydrological cycles. However, ongoing climate change and increased in CO2 concentration in the atmosphere (ca) are expected to alter growth and gas exchange of trees, and ultimately forest productivity. Still, the magnitude of these effects is unclear. A better comprehension of the species-specific responses to environmental changes will better inform models and managers on the vulnerability and resiliency of these forests. Tree-ring analysis was combined with δ¹³C and δ18O measurements to investigate growth and physiological responses of red oak (Quercus rubra L.) and tulip poplar (Liriodendron tulipifera L.) in northeastern US to changes in water availability and ca for the period 1950-2014. We found very strong correlations between summer climatic water balance (June-August) and isotopic tree-ring series for δ¹³C (r = -0.65 and -0.73), and δ18O (r = -0.59 and -0.70), for red oak and tulip poplar, respectively. In contrast, tree-ring width was less sensitive to summer water availability (r = 0.33-0.39). Prior to the mid 1980s, low water availability resulted in low stomatal conductance, photosynthesis, and growth. Since that period, pluvial conditions occurring in northeastern US have increased stomatal conductance, carbon uptake, and growth of both species. These findings demonstrate that broadleaf trees in this region could be more sensitive to drought than expected. This appears especially true since much of the calibration period looks wet in a multi-centennial perspective. Further, stronger spatial correlations were found between climate data with tree-ring isotopes than with tree-ring width and the geographical area of the observed δ18O-precipitation response (i.e. the area over which correlations are > 0.5) covers most of the northeastern US. Given the good fit between the isotopic time series and water

  10. Terrestrial carbon balance in a drier world: the effects of water availability in southwestern North America.

    PubMed

    Biederman, Joel A; Scott, Russell L; Goulden, Michael L; Vargas, Rodrigo; Litvak, Marcy E; Kolb, Thomas E; Yepez, Enrico A; Oechel, Walter C; Blanken, Peter D; Bell, Tom W; Garatuza-Payan, Jaime; Maurer, Gregory E; Dore, Sabina; Burns, Sean P

    2016-05-01

    Global modeling efforts indicate semiarid regions dominate the increasing trend and interannual variation of net CO2 exchange with the atmosphere, mainly driven by water availability. Many semiarid regions are expected to undergo climatic drying, but the impacts on net CO2 exchange are poorly understood due to limited semiarid flux observations. Here we evaluated 121 site-years of annual eddy covariance measurements of net and gross CO2 exchange (photosynthesis and respiration), precipitation, and evapotranspiration (ET) in 21 semiarid North American ecosystems with an observed range of 100 - 1000 mm in annual precipitation and records of 4-9 years each. In addition to evaluating spatial relationships among CO2 and water fluxes across sites, we separately quantified site-level temporal relationships, representing sensitivity to interannual variation. Across the climatic and ecological gradient, photosynthesis showed a saturating spatial relationship to precipitation, whereas the photosynthesis-ET relationship was linear, suggesting ET was a better proxy for water available to drive CO2 exchanges after hydrologic losses. Both photosynthesis and respiration showed similar site-level sensitivity to interannual changes in ET among the 21 ecosystems. Furthermore, these temporal relationships were not different from the spatial relationships of long-term mean CO2 exchanges with climatic ET. Consequently, a hypothetical 100-mm change in ET, whether short term or long term, was predicted to alter net ecosystem production (NEP) by 64 gCm(-2) yr(-1). Most of the unexplained NEP variability was related to persistent, site-specific function, suggesting prioritization of research on slow-changing controls. Common temporal and spatial sensitivity to water availability increases our confidence that site-level responses to interannual weather can be extrapolated for prediction of CO2 exchanges over decadal and longer timescales relevant to societal response to climate change.

  11. Removing inorganics: Common methods have limits

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

    Sorg, T.J.

    1991-06-01

    When EPA sets a regulation (a maximum contaminant level) for a contaminant, it must also specify the best available technology (BAT) that can be used to remove the contaminant. Because the regulations apply to community water systems, the technologies selected are ones that are commonly used to treat community size water systems. Thus, EPA R and D program has focused its efforts on evaluating primarily community applied technologies such as conventional coagulation-filtration, lime softening, ion exchange, adsorption, and membrane process. When BAT is identified for a specific contaminant, frequently the BAT will be listed with its limitations because the processmore » is often not effective under all water quality conditions. The same limitations would also apply to POU/POE treatment. The paper discusses EPA's regulations on inorganic contaminants, the best available technologies cited by EPA, and the limitations of the processes. Using arsenic as an example, the impact of the contaminant chemistry and water quality on removals is presented.« less

  12. Water availability predicts forest canopy height at the global scale.

    PubMed

    Klein, Tamir; Randin, Christophe; Körner, Christian

    2015-12-01

    The tendency of trees to grow taller with increasing water availability is common knowledge. Yet a robust, universal relationship between the spatial distribution of water availability and forest canopy height (H) is lacking. Here, we created a global water availability map by calculating an annual budget as the difference between precipitation (P) and potential evapotranspiration (PET) at a 1-km spatial resolution, and in turn correlated it with a global H map of the same resolution. Across forested areas over the globe, Hmean increased with P-PET, roughly: Hmean (m) = 19.3 + 0.077*(P-PET). Maximum forest canopy height also increased gradually from ~ 5 to ~ 50 m, saturating at ~ 45 m for P-PET > 500 mm. Forests were far from their maximum height potential in cold, boreal regions and in disturbed areas. The strong association between forest height and P-PET provides a useful tool when studying future forest dynamics under climate change, and in quantifying anthropogenic forest disturbance. © 2015 John Wiley & Sons Ltd/CNRS.

  13. Water use and availability in the Woonasquatucket and Moshassuck River basins, north-central Rhode Island

    USGS Publications Warehouse

    Nimiroski, Mark T.; Wild, Emily C.

    2005-01-01

    The Woonasquatucket River Basin includes 51.0 square miles, and the Moshassuck River Basin includes 23.8 square miles in north-central Rhode Island. The study area comprises these two basins. The two basins border each other with the Moshassuck River Basin to the northeast of the Woonasquatucket River Basin. Seven towns are in the Woonasquatucket River Basin, and six towns are in the Moshassuck River Basin. To determine the water use and availability in the study area, water supply and discharge data were collected for these river basins for the 1995–99 period, and compared to estimated long-term water available. The study area is unique in the State of Rhode Island, because no withdrawals from major public suppliers were made during the study period. Withdrawals were, therefore, limited to self-supplied domestic use, two minor suppliers, and one self-supplied industrial user. Because no metered data were available, the summer water withdrawals were assumed to be the same as the estimates for the rest of the year. Seven major water suppliers distribute an average of 17.564 million gallons per day for use in the study area from sources outside of the study area. The withdrawals from minor water suppliers were 0.017 million gallons per day in the study area, all in the town of Smithfield in the Woonasquatucket River Basin. The remaining withdrawals in the study area were estimated to be 0.731 million gallons per day by self-supplied domestic, commercial, industrial, and agricultural users. Return flows in the study area included self-disposed water and disposal from permitted dischargers, including the Smithfield Sewage Treatment Plant. Return flows accounted for 4.116 million gallons per day in the study area. Most public-disposed water (15.195 million gallons per day) is collected by the Narragansett Bay Commission and is disposed outside of the basin in Narragansett Bay. The PART program, a computerized hydrograph-separation application, was used at one index

  14. Stover removal effects on seasonal soil water availability under full and deficit irrigation

    USDA-ARS?s Scientific Manuscript database

    Removing corn (Zea mays L.) stover for livestock feed or bioenergy feedstock may impact water availability in the soil profile to support crop growth. The role of stover in affecting soil profile water availability will depend on annual rainfall inputs as well as irrigation level. To assess how res...

  15. Responses of plant available water and forest productivity to variably layered coarse textured soils

    NASA Astrophysics Data System (ADS)

    Huang, Mingbin; Barbour, Lee; Elshorbagy, Amin; Si, Bing; Zettl, Julie

    2010-05-01

    Reforestation is a primary end use for reconstructed soils following oil sands mining in northern Alberta, Canada. Limited soil water conditions strongly restrict plant growth. Previous research has shown that layering of sandy soils can produce enhanced water availability for plant growth; however, the effect of gradation on these enhancements is not well defined. The objective of this study was to evaluate the effect of soil texture (gradation and layering) on plant available water and consequently on forest productivity for reclaimed coarse textured soils. A previously validated system dynamics (SD) model of soil moisture dynamics was coupled with ecophysiological and biogeochemical processes model, Biome-BGC-SD, to simulate forest dynamics for different soil profiles. These profiles included contrasting 50 cm textural layers of finer sand overlying coarser sand in which the sand layers had either a well graded or uniform soil texture. These profiles were compared to uniform profiles of the same sands. Three tree species of jack pine (Pinus banksiana Lamb.), white spruce (Picea glauce Voss.), and trembling aspen (Populus tremuloides Michx.) were simulated using a 50 year climatic data base from northern Alberta. Available water holding capacity (AWHC) was used to identify soil moisture regime, and leaf area index (LAI) and net primary production (NPP) were used as indices of forest productivity. Published physiological parameters were used in the Biome-BGC-SD model. Relative productivity was assessed by comparing model predictions to the measured above-ground biomass dynamics for the three tree species, and was then used to study the responses of forest leaf area index and potential productivity to AWHC on different soil profiles. Simulated results indicated soil layering could significantly increase AWHC in the 1-m profile for coarse textured soils. This enhanced AWHC could result in an increase in forest LAI and NPP. The increased extent varied with soil

  16. Revegetation in China’s Loess Plateau is approaching sustainable water resource limits

    NASA Astrophysics Data System (ADS)

    Feng, Xiaoming; Fu, Bojie; Piao, Shilong; Wang, Shuai; Ciais, Philippe; Zeng, Zhenzhong; Lü, Yihe; Zeng, Yuan; Li, Yue; Jiang, Xiaohui; Wu, Bingfang

    2016-11-01

    Revegetation of degraded ecosystems provides opportunities for carbon sequestration and bioenergy production. However, vegetation expansion in water-limited areas creates potentially conflicting demands for water between the ecosystem and humans. Current understanding of these competing demands is still limited. Here, we study the semi-arid Loess Plateau in China, where the `Grain to Green’ large-scale revegetation programme has been in operation since 1999. As expected, we found that the new planting has caused both net primary productivity (NPP) and evapotranspiration (ET) to increase. Also the increase of ET has induced a significant (p < 0.001) decrease in the ratio of river runoff to annual precipitation across hydrological catchments. From currently revegetated areas and human water demand, we estimate a threshold of NPP of 400 +/- 5 g C m-2 yr-1 above which the population will suffer water shortages. NPP in this region is found to be already close to this limit. The threshold of NPP could change by -36% in the worst case of climate drying and high human withdrawals, to +43% in the best case. Our results develop a new conceptual framework to determine the critical carbon sequestration that is sustainable in terms of both ecological and socio-economic resource demands in a coupled anthropogenic-biological system.

  17. Available water modifications by topsoil treatments under mediterranean semiarid conditions: afforestation plan

    NASA Astrophysics Data System (ADS)

    Hueso Gonzalez, Paloma; Francisco Martinez Murillo, Juan; Damian Ruiz Sinoga, Jose

    2016-04-01

    During dry periods in the Mediterranean area, the lack of water entering the soil matrix reduces organic contributions to the soil. These processes lead to reduced soil fertility and soil vegetation recovery which creates a positive feedback process that can lead to desertification. Restoration of native vegetation is the most effective way to regenerate soil health, and control runoff and sediment yield. In Mediterranean areas, after a forestry proposal, it is highly common to register a significant number of losses for the saplings that have been introduced due to the lack of rainfall. When no vegetation is established, organic amendments can be used to rapidly protect the soil surface against the erosive forces of rain and runoff. In this study we investigated the hydrological effects of five soil treatments in relation to the temporal variability of the available water for plants. Five amendments were applied in an experimental set of plots: straw mulching; mulch with chipped branches of Aleppo Pine (Pinus halepensis L.); TerraCotten hydroabsobent polymers; sewage sludge; sheep manure and control. Plots were afforested following the same spatial pattern, and amendments were mixed with the soil at the rate 10 Mg ha-1. In control plots, during June, July, August and September, soils were registered below the wilting point, and therefore, in the area of water unusable by plants. These months were coinciding with the summer mediterranean drought. This fact justifies the high mortality found on plants after the seeding plan. Similarly, soils have never exceeded the field capacity value measured for control plots. Conversely, in the straw and pinus mulch, soils were above the wilting point during a longer time than in control plots. Thus, the soil moisture only has stayed below the 4.2 pF suction in July, July and August. Regarding the amount of water available was also higher, especially in the months of December, January and February. However, the field capacity

  18. Viability of commercially available bleach for water treatment in developing countries.

    PubMed

    Lantagne, Daniele S

    2009-11-01

    Treating household water with low-cost, widely available commercial bleach is recommended by some organizations to improve water quality and reduce disease in developing countries. I analyzed the chlorine concentration of 32 bleaches from 12 developing countries; the average error between advertised and measured concentration was 35% (range = -45%-100%; standard deviation = 40%). Because of disparities between advertised and actual concentration, the use of commercial bleach for water treatment in developing countries is not recommended without ongoing quality control testing.

  19. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 816.42 Section 816.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and effluent...

  20. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 817.42 Section 817.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and effluent...

  1. 30 CFR 817.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 817.42 Section 817.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.42 Hydrologic balance: Water quality standards and effluent...

  2. 30 CFR 816.42 - Hydrologic balance: Water quality standards and effluent limitations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Hydrologic balance: Water quality standards and effluent limitations. 816.42 Section 816.42 Mineral Resources OFFICE OF SURFACE MINING RECLAMATION AND... STANDARDS-SURFACE MINING ACTIVITIES § 816.42 Hydrologic balance: Water quality standards and effluent...

  3. The Coupling of Ecosystem Productivity and Water Availability in Dryland Regions

    NASA Astrophysics Data System (ADS)

    Scott, R. L.; Biederman, J. A.; Barron-Gafford, G.

    2014-12-01

    Land cover and climatic change will alter biosphere-atmosphere exchanges of water vapor and carbon dioxide depending, in part, on feedbacks between biotic activity and water availability. Eddy covariance observations allow us to estimate ecosystem-scale productivity and respiration, and these datasets are now becoming sufficiently mature to advance understanding of these ecohydrological interactions. Here we use a network of sites in semiarid western North America representing gradients of water availability and functional plant type. We examine how precipitation (P) controls evapotranspiration (ET), net ecosystem production (NEP), and its component fluxes of ecosystem respiration (Reco) and gross ecosystem production (GEP). Despite the high variability in seasonal and annual precipitation timing and amounts that we expect to influence ecosystem function, we find persistent overall relationships between P or ET and the fluxes of NEP, Reco and GEP across the network, indicating a commonality and resilience in ecosystem soil and plant response to water availability. But we also observe several important site differences such as prior seasonal legacy effects on subsequent fluxes which vary depending on dominant plant functional type. For example, multiyear droughts, episodic cool-season droughts, and hard winter freezes seem to affect the herbaceous species differently than the woody ones. Nevertheless, the overall, strong coupling between hydrologic and ecologic processes at these sites bolsters our ability to predict the response of dryland ecosystems to future precipitation change.

  4. Surface water-quality assessment of the lower Kansas River basin, Kansas and Nebraska: analysis of available water-quality data through 1986

    USGS Publications Warehouse

    Jordan, P.R.; Stamer, J.K.

    1991-01-01

    Beginning in 1986, the U.S. Congress appropriated funds for the U.S. Geological Survey to test and refine concepts for a National Water-Quality Assessment (NAWQA) Program. The long-term goals of the full-scale program are to: (1) provide a nationally consistent description of current water-quality conditions for a large part of the Nation's surface- and ground-water resources; (2) define long-term trends (or lack of trends) in water quality; and (3) identify, describe, and explain, insofar as possible, the major factors that affect current conditions and trends in water quality. This information, obtained on a continuing basis, will be made available to water managers, policy makers, and the public to provide an improved scientific basis for evaluating the effectiveness of water-quality-management programs and for predicting the likely effects of contemplated changes in land-and water-management practices. At present (1990), the assessment program is in a pilot phase in seven areas that represent diverse hydrologic environments and water-quality conditions.This report completes one of the first activities undertaken as part of the lower Kansas River basin pilot study, which was to compile, screen, and interpret available water-quality data for the study unit through 1986. The report includes information on the sources and types of water-quality data available, the utility of available water-quality data for assessment purposes, and a description of current water-quality conditions and trends and their relation to natural and human factors.

  5. Least limiting water range of Udox soil under degraded pastures on different sun-exposed faces

    NASA Astrophysics Data System (ADS)

    Passos, Renato Ribeiro; Marciano da Costa, Liovando; Rodrigues de Assis, Igor; Santos, Danilo Andrade; Ruiz, Hugo Alberto; Guimarães, Lorena Abdalla de Oliveira Prata; Andrade, Felipe Vaz

    2017-07-01

    The efficient use of water is increasingly important and proper soil management, within the specificities of each region of the country, allows achieving greater efficiency. The South and Caparaó regions of Espírito Santo, Brazil are characterized by relief of `hill seas' with differences in the degree of pasture degradation due to sun exposure. The objective of this study was to evaluate the least limiting water range in Udox soil under degraded pastures with two faces of exposure to the sun and three pedoenvironments. In each pedoenvironment, namely Alegre, Celina, and Café, two areas were selected, one with exposure on the North/West face and the other on the South/East face. In each of these areas, undisturbed soil samples were collected at 0-10 cm depth to determine the least limiting water range. The exposed face of the pasture that received the highest solar incidence (North/West) presented the lowest values in least limiting water range. The least limiting water range proved to be a physical quality indicator for Udox soil under degraded pastures.

  6. Middle-term metropolitan water availability index assessment based on synergistic potentials of multi-sensor data

    NASA Astrophysics Data System (ADS)

    Chang, Ni-Bin; Yang, Y. Jeffrey; Daranpob, Ammarin

    2010-03-01

    The impact of recent drought and water pollution episodes results in an acute need to project future water availability to assist water managers in water utility infrastructure management within many metropolitan regions. Separate drought and water quality indices previously developed might not be sufficient for the purpose of such an assessment. This paper describes the development of the "Metropolitan Water Availability Index (MWAI)" and its potential applications in assessing the middle-term water availability at the watershed scale in a fast growing metropolitan region - the Manatee County near Tampa Bay, Florida, U.S.A. The MWAI framework is based on a statistical approach that seeks to reflect the continuous spatial and temporal variations of both water quantity and quality using a simple numerical index. Such a trend analysis will surely result in the final MWAI values for regional water management systems within a specified range. By using remote sensing technologies and data processing techniques, continuous monitoring of spatial and temporal distributions of key water availability variables, such as evapotranspiration (ET) and precipitation, is made achievable. These remote sensing technologies can be ground-based (e.g., radar estimates of rainfall), or based on remote sensing data gathered by aircraft or satellites. Using a middle term historical record, the MWAI was applied to the Manatee County water supplies. The findings clearly indicate that only eight out of twelve months in 2008 had positive MWAI values during the year. Such numerical findings are consistent with the observational evidence of statewide drought events in 2006-2008, which implies the time delay between the ending of severe drought period and the recovery of water availability in MWAI. It is expected that this forward-looking novel water availability forecasting platform will help provide a linkage in methodology between strategic planning, master planning, and the plant operation

  7. Water use, availability, and net demand in the Tennessee River watershed within Alabama, 2005

    USGS Publications Warehouse

    Gill, Amy C.; Harper, Michael J.; Littlepage, Thomas M.

    2013-01-01

    The U.S. Geological Survey worked in cooperation with the Alabama Department of Economic and Community Affairs—Office of Water Resources to estimate water use and water availability for 2005 for the portion of the Tennessee River watershed contained within the borders of the State of Alabama. Estimates of water use and availability are an important part of planning for population and economic growth in the Tennessee River watershed in Alabama. Total water use for the region in 2005 was 5,197 million gallons per day (Mgal/d). Total surface-water withdrawals were 5,139 Mgal/d, and total groundwater withdrawals were about 58 Mgal/d. About 92 percent of the total water withdrawn was surface water used for once-through cooling for thermoelectric power generation. Self-supplied industrial and public-supply water uses accounted for the next greatest uses of water, constituting approximately 49 and 42 percent, respectively, of the total water use excluding thermoelectric power use. Summaries of water use by county and subbasin indicated the areas of greatest water withdrawals and use within the Tennessee River watershed. Limestone (2,012 Mgal/d), Jackson (1,498 Mgal/d), and Colbert (1,363 Mgal/d) Counties were the counties with the greatest total water use in 2005 and had large amounts of water withdrawn for thermoelectric power generation. When water use from thermoelectric power generation was not considered, the counties with the greatest withdrawals were Morgan (124 Mgal/d), Madison (72 Mgal/d), Colbert (69 Mgal/d), and Lawrence (67 Mgal/d). The subbasin with the greatest total water use was Wheeler Lake (2,260 Mgal/d) in the Middle Tennessee—Elk subregion. Wheeler Lake subbasin also had the greatest public-supply, irrigation, industrial, mining, and thermoelectric withdrawals of any subbasin in the Tennessee River watershed within Alabama. Total water availability for the Tennessee River watershed within Alabama was estimated to be 34,567 Mgal/d by the Geological

  8. Safety of packaged water distribution limited by household recontamination in rural Cambodia.

    PubMed

    Holman, Emily J; Brown, Joe

    2014-06-01

    Packaged water treatment schemes represent a growing model for providing safer water in low-income settings, yet post-distribution recontamination of treated water may limit this approach. This study evaluates drinking water quality and household water handling practices in a floating village in Tonlé Sap Lake, Cambodia, through a pilot cross-sectional study of 108 households, approximately half of which used packaged water as the main household drinking water source. We hypothesized that households purchasing drinking water from local packaged water treatment plants would have microbiologically improved drinking water at the point of consumption. We found no meaningful difference in microbiological drinking water quality between households using packaged, treated water and those collecting water from other sources, including untreated surface water, however. Households' water storage and handling practices and home hygiene may have contributed to recontamination of drinking water. Further measures to protect water quality at the point-of-use may be required even if water is treated and packaged in narrow-mouthed containers.

  9. Water availability and use pilot; methods development for a regional assessment of groundwater availability, southwest alluvial basins, Arizona

    USGS Publications Warehouse

    Tillman, Fred D.; Cordova, Jeffrey T.; Leake, Stanley A.; Thomas, Blakemore E.; Callegary, James B.

    2011-01-01

    Executive Summary: Arizona is located in an arid to semiarid region in the southwestern United States and is one of the fastest growing States in the country. Population in Arizona surpassed 6.5 million people in 2008, an increase of 140 percent since 1980, when the last regional U.S. Geological Survey (USGS) groundwater study was done as part of the Regional Aquifer System Analysis (RASA) program. The alluvial basins of Arizona are part of the Basin and Range Physiographic Province and cover more than 73,000 mi2, 65 percent of the State's total land area. More than 85 percent of the State's population resides within this area, accounting for more than 95 percent of the State's groundwater use. Groundwater supplies in the area are expected to undergo further stress as an increasing population vies with the State's important agricultural sector for access to these limited resources. To provide updated information to stakeholders addressing issues surrounding limited groundwater supplies and projected increases in groundwater use, the USGS Groundwater Resources Program instituted the Southwest Alluvial Basins Groundwater Availability and Use Pilot Program to evaluate the availability of groundwater resources in the alluvial basins of Arizona. The principal products of this evaluation of groundwater resources are updated groundwater budget information for the study area and a proof-of-concept groundwater-flow model incorporating several interconnected groundwater basins. This effort builds on previous research on the assessment and mapping of groundwater conditions in the alluvial basins of Arizona, also supported by the USGS Groundwater Resources Program. Regional Groundwater Budget: The Southwest Alluvial Basins-Regional Aquifer System Analysis (SWAB-RASA) study produced semiquantitative groundwater budgets for each of the alluvial basins in the SWAB-RASA study area. The pilot program documented in this report developed new quantitative estimates of groundwater

  10. Soil Water Balance and Vegetation Dynamics in two Water-limited Mediterranean Ecosystem on Sardinia under past and future climate change

    NASA Astrophysics Data System (ADS)

    Corona, R.; Montaldo, N.; Albertson, J. D.

    2016-12-01

    Water limited conditions strongly impacts soil and vegetation dynamics in Mediterranean regions, which are commonly heterogeneous ecosystems, characterized by inter-annual rainfall variability, topography variability and contrasting plant functional types (PFTs) competing for water use. Historical human influences (e.g., deforestation, urbanization) further altered these ecosystems. Sardinia island is a representative region of Mediterranean ecosystems. It is low urbanized except some plan areas close to the main cities where main agricultural activities are concentrated. Two contrasting case study sites are within the Flumendosa river basin (1700 km2). The first site is a typical grassland on an alluvial plan valley (soil depth > 2m) while the second is a patchy mixture of Mediterranean vegetation species (mainly wild olive trees and C3 herbaceous) that grow in a soil bounded from below by a rocky layer of basalt, partially fractured (soil depth 15 - 40 cm). In both sites land-surface fluxes and CO2 fluxes are estimated by the eddy correlation technique while soil moisture was continuously estimated with water content reflectometers, and periodically leaf area index (LAI) was estimated. The following objectives are addressed:1) pointing out the dynamics of land surface fluxes, soil moisture, CO2 and vegetation cover for two contrasting water-limited ecosystems; 2) assess the impact of the soil depth and type on the CO2 and water balance dynamics; 3) evaluate the impact of past and future climate change scenarios on the two contrasting ecosystems. For reaching the objectives an ecohydrologic model that couples a vegetation dynamic model (VDM), and a 3-component (bare soil, grass and woody vegetation) land surface model (LSM) has been used. Historical meteorological data are available from 1922 and hydro-meteorological scenarios are then generated using a weather generator. The VDM-LSM model predict soil water balance and vegetation dynamics for the generated

  11. Water availability and vulnerability of 225 large cities in the United States

    NASA Astrophysics Data System (ADS)

    Padowski, Julie C.; Jawitz, James W.

    2012-12-01

    This study presents a quantitative national assessment of urban water availability and vulnerability for 225 U.S. cities with population greater than 100,000. Here, the urban assessments account for not only renewable water flows, but also the extracted, imported, and stored water that urban systems access through constructed infrastructure. These sources represent important hydraulic components of the urban water supply, yet are typically excluded from water scarcity assessments. Results from this hydraulic-based assessment were compared to those obtained using a more conventional method that estimates scarcity solely based on local renewable flows. The inclusion of hydraulic components increased the mean availability to cities, leading to a significantly lower portion of the total U.S. population considered "at risk" for water scarcity (17%) than that obtained from the runoff method (47%). Water vulnerability was determined based on low-flow conditions, and smaller differences were found for this metric between at-risk populations using the runoff (66%) and hydraulic-based (54%) methods. The large increase in the susceptible population between the scarcity measures evaluated using the hydraulic method may better reconcile the seeming contradiction in the United States between perceptions of natural water abundance and widespread water scarcity. Additionally, urban vulnerability measures developed here were validated using a media text analysis. Vulnerability assessments that included hydraulic components were found to correlate with the frequency of urban water scarcity reports in the popular press while runoff-based measures showed no significant correlation, suggesting that hydraulic-based assessments provide better context for understanding the nature and severity of urban water scarcity issues.

  12. Enhanced monitoring of the temporal and spatial relationships between water demand and water availability

    NASA Astrophysics Data System (ADS)

    Schneider, C. A.; Aggett, G. R.; Hattendorf, M. J.

    2007-12-01

    Better information on evapotranspiration (ET) is essential to better understanding of consumptive use of water by crops. RTi is using NASA Earth-sun System research results and METRIC (Mapping ET at high Resolution with Internalized Calibration) to increase the repeatability and accuracy of consumptive use estimates. METRIC, an image-processing model for calculating ET as a residual of the surface energy balance, utilizes the thermal band on various satellite remote sensors. Calculating actual ET from satellites can avoid many of the assumptions driving other methods of calculating ET over a large area. Because it is physically based and does not rely on explicit knowledge of crop type in the field, a large potential source of error should be eliminated. This paper assesses sources of error in current operational estimates of ET for an area of the South Platte irrigated lands of Colorado, and benchmarks potential improvements in the accuracy of ET estimates gained using METRIC, as well as the processing efficiency of consumptive use demand for large irrigated lands. Examples highlighting how better water planning decisions and water management can be achieved via enhanced monitoring of the temporal and spatial relationships between water demand and water availability are provided.

  13. Viability of Commercially Available Bleach for Water Treatment in Developing Countries

    PubMed Central

    2009-01-01

    Treating household water with low-cost, widely available commercial bleach is recommended by some organizations to improve water quality and reduce disease in developing countries. I analyzed the chlorine concentration of 32 bleaches from 12 developing countries; the average error between advertised and measured concentration was 35% (range = –45%–100%; standard deviation = 40%). Because of disparities between advertised and actual concentration, the use of commercial bleach for water treatment in developing countries is not recommended without ongoing quality control testing. PMID:19762657

  14. Dispersal Limitations on Fish Community Recovery Following Long-term Water Quality Remediation

    DOE PAGES

    McManamay, Ryan A.; Jett, Robert T.; Ryon, Michael G.; ...

    2016-02-22

    Holistic restoration approaches, such as water quality remediation, are likely to meet conservation objectives because they are typically implemented at watershed scales, as opposed to individual stream reaches. However, habitat fragmentation may impose constraints on the ecological effectiveness of holistic restoration strategies by limiting colonization following remediation. We questioned the importance of dispersal limitations to fish community recovery following long-term water quality remediation and species reintroductions across the White Oak Creek (WOC) watershed near Oak Ridge, Tennessee (USA). Long-term (26 years) responses in fish species richness and biomass to water quality remediation were evaluated in light of habitat fragmentation andmore » population isolation from instream barriers, which varied in their passage potential. In addition, ordination techniques were used to determine the relative importance of habitat connectivity and water quality, in explaining variation fish communities relative to environmental fluctuations, i.e. streamflow. Ecological recovery (changes in richness) at each site was negatively related to barrier index, a measure of community isolation by barriers relative to stream distance. Following species reintroductions, dispersal by fish species was consistently in the downstream direction and upstream passage above barriers was non-existent. The importance of barrier index in explaining variation in fish communities was stronger during higher flow conditions, but decreased over time an indication of increasing community stability and loss of seasonal migrants. Compared to habitat fragmentation, existing water quality concerns (i.e., outfalls, point source discharges) were unrelated to ecological recovery, but explained relatively high variation in community dynamics. Our results suggest that habitat fragmentation limited the ecological effectiveness of intensive water quality remediation efforts and fish reintroduction

  15. Dispersal Limitations on Fish Community Recovery Following Long-term Water Quality Remediation

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

    McManamay, Ryan A.; Jett, Robert T.; Ryon, Michael G.

    Holistic restoration approaches, such as water quality remediation, are likely to meet conservation objectives because they are typically implemented at watershed scales, as opposed to individual stream reaches. However, habitat fragmentation may impose constraints on the ecological effectiveness of holistic restoration strategies by limiting colonization following remediation. We questioned the importance of dispersal limitations to fish community recovery following long-term water quality remediation and species reintroductions across the White Oak Creek (WOC) watershed near Oak Ridge, Tennessee (USA). Long-term (26 years) responses in fish species richness and biomass to water quality remediation were evaluated in light of habitat fragmentation andmore » population isolation from instream barriers, which varied in their passage potential. In addition, ordination techniques were used to determine the relative importance of habitat connectivity and water quality, in explaining variation fish communities relative to environmental fluctuations, i.e. streamflow. Ecological recovery (changes in richness) at each site was negatively related to barrier index, a measure of community isolation by barriers relative to stream distance. Following species reintroductions, dispersal by fish species was consistently in the downstream direction and upstream passage above barriers was non-existent. The importance of barrier index in explaining variation in fish communities was stronger during higher flow conditions, but decreased over time an indication of increasing community stability and loss of seasonal migrants. Compared to habitat fragmentation, existing water quality concerns (i.e., outfalls, point source discharges) were unrelated to ecological recovery, but explained relatively high variation in community dynamics. Our results suggest that habitat fragmentation limited the ecological effectiveness of intensive water quality remediation efforts and fish reintroduction

  16. Hydrologic models and analysis of water availability in Cuyama Valley, California

    USGS Publications Warehouse

    Hanson, R.T.; Flint, Lorraine E.; Faunt, Claudia C.; Gibbs, Dennis R.; Schmid, Wolfgang

    2014-01-01

    Changes in population, agricultural development practices (including shifts to more water-intensive crops), and climate variability are placing increasingly larger demands on available water resources, particularly groundwater, in the Cuyama Valley, one of the most productive agricultural regions in Santa Barbara County. The goal of this study was to produce a model capable of being accurate at scales relevant to water management decisions that could be considered in the evaluation of the sustainable water supply. The Cuyama Valley Hydrologic Model (CUVHM) was designed to simulate the most important natural and human components of the hydrologic system, including components dependent on variations in climate, thereby providing a reliable assessment of groundwater conditions and processes that can inform water users and help to improve planning for future conditions. Model development included a revision of the conceptual model of the flow system, construction of a precipitation-runoff model using the Basin Characterization Model (BCM), and construction of an integrated hydrologic flow model with MODFLOW-One-Water Hydrologic Flow Model (MF-OWHM). The hydrologic models were calibrated to historical conditions of water and land use and, then, used to assess the use and movement of water throughout the Valley. These tools provide a means to understand the evolution of water use in the Valley, its availability, and the limits of sustainability. The conceptual model identified inflows and outflows that include the movement and use of water in both natural and anthropogenic systems. The groundwater flow system is characterized by a layered geologic sedimentary sequence that—in combination with the effects of groundwater pumping, natural recharge, and the application of irrigation water at the land surface—displays vertical hydraulic-head gradients. Overall, most of the agricultural demand for water in the Cuyama Valley in the initial part of the growing season is

  17. Groundwater availability as constrained by hydrogeology and environmental flows

    USGS Publications Warehouse

    Watson, Katelyn A.; Mayer, Alex S.; Reeves, Howard W.

    2014-01-01

    Groundwater pumping from aquifers in hydraulic connection with nearby streams has the potential to cause adverse impacts by decreasing flows to levels below those necessary to maintain aquatic ecosystems. The recent passage of the Great Lakes-St. Lawrence River Basin Water Resources Compact has brought attention to this issue in the Great Lakes region. In particular, the legislation requires the Great Lakes states to enact measures for limiting water withdrawals that can cause adverse ecosystem impacts. This study explores how both hydrogeologic and environmental flow limitations may constrain groundwater availability in the Great Lakes Basin. A methodology for calculating maximum allowable pumping rates is presented. Groundwater availability across the basin may be constrained by a combination of hydrogeologic yield and environmental flow limitations varying over both local and regional scales. The results are sensitive to factors such as pumping time, regional and local hydrogeology, streambed conductance, and streamflow depletion limits. Understanding how these restrictions constrain groundwater usage and which hydrogeologic characteristics and spatial variables have the most influence on potential streamflow depletions has important water resources policy and management implications.

  18. Long term growth responses of loblolly pine to optimal nutrient and water resource availability

    Treesearch

    Timothy J. Albaugh; H. Lee Allen; Phillip M. Dougherty; Kurt H. Johnsen

    2004-01-01

    A factorial combination of four treatments (control (CW), optimal growing season water availability (IW), optimum nutrient availability (FW), and combined optimum water and nutrient availability (FIW)) in four replications were initiated in an 8-year- old Pinus taeda stand growing on a droughty, nutrient-poor, sandy site in Scotland County, NC and...

  19. Availability, Sustainability, and Suitability of Ground Water, Rogers Mesa, Delta County, Colorado - Types of Analyses and Data for Use in Subdivision Water-Supply Reports

    USGS Publications Warehouse

    Watts, Kenneth R.

    2008-01-01

    Mesa consists of alluvial-fan deposits that overlie shale and, locally, sandstone. Maps of the base of the aquifer, the water table, and the saturated thickness of the aquifer were prepared from data from the well files of the Colorado Division of Water Resources. The base of the aquifer generally is topographically higher than the valleys of the North Fork Gunnison River and Leroux Creek, and direct hydraulic connection of the aquifer to North Fork Gunnison River and Leroux Creek is limited. The aquifer is recharged primarily by infiltration of surface water diverted for irrigation. Ground water discharges to seeps and springs and through slope deposits at the boundaries of the aquifer. Data from the well files also were used to estimate the specific capacity of wells and to estimate the transmissivity and hydraulic conductivity of the aquifer. A water budget was used to estimate recharge to and discharge from the aquifer. Although storage within the aquifer likely varies seasonally and from year to year, it was assumed that there were no long-term changes in ground-water storage. Estimated average annual recharge to and discharge from the aquifer during November 1998 through October 2006 were about 30,767 acre-feet per year. Although sufficient ground water is available on Rogers Mesa for additional domestic water supplies, conversion of irrigated land to residential land use likely would reduce recharge to the aquifer, affecting the sustainability of ground-water supplies on Rogers Mesa. Stream-depletion analyses indicate that the ground water in the aquifer likely would be considered tributary ground water and additional uses of ground water to supply new subdivisions likely would require implementation of augmentation plans. Although sufficient ground water is available on Rogers Mesa for additional domestic water supplies, conversion of irrigated land to residential land use likely would reduce recharge to the aquifer, affecting the sustainability

  20. Water Availability for Synthetic Fuels: An Assessment of Current Studies

    DOT National Transportation Integrated Search

    1982-10-01

    The objective of this study is to describe and analyze the hydrologic, institutional, legal, and economic issues involved in assessing and interpreting estimates of water availability for synfuels development in four major river basins: (1) Upper Mis...

  1. Water availability and genetic effects on wood properties of loblolly pine (Pinus taeda)

    Treesearch

    C. A. Gonzalez-Benecke; T. A. Martin; Alexander Clark; G. F. Peter

    2010-01-01

    We studied the effect of water availability on basal area growth and wood properties of 11-year-old loblolly pine (Pinus taeda L.) trees from contrasting Florida (FL) (a mix of half-sib families) and South Carolina coastal plain (SC) (a single, half-sib family) genetic material. Increasing soil water availability via irrigation increased average wholecore specific...

  2. Biomass of active microorganisms is not limited only by available carbon in the rhizosphere

    NASA Astrophysics Data System (ADS)

    Gilmullina, Aliia

    2017-04-01

    Microbial activity is generally limited by carbon (C) availability. The easily available substrate release by roots creates so called "hotspots" in the rhizosphere that drives microbial activity removing C limitation. We simulated a gradient of root exudates by glucose addition at different concentrations to stimulate the activation of microbial biomass (MB). Glucose was added at the rates lower than MB (5, 10, 25 and 50%) and at the rates similar or higher than MB (100, 150, 200, 250, 300 and 400%). During incubation CO2 efflux was measured by conductometry, the size of active MB and specific growth rate were estimated by substrate-induced growth response method. We tested a hypothesis that glucose addition exceeding 100% MB is able to activate major fraction of soil microbial community. Addition of glucose at concentrations higher than 5% decreased specific growth rate, demonstrating the shift of microbial community from r-strategy to K-strategy. The percentage of active MB grew up by the increase of glucose concentration. The treatment with glucose at 100% presented a dramatic shift in the activation of MB up to 14%. Contrary to our hypothesis, further increase in glucose rate caused moderate stimulation of active MB up to 22% of total MB. Furthermore, glucose addition above 200% did not increase the fraction of active biomass indicating glucose oversaturation and possible limitation by other nutrients. The results suggest that despite the fact that C is the most important limitation factor, limitless C supply is not able to activate MB up to 100%. Thus, if the rhizosphere is limited by nutrients, the fraction of active biomass remains at low level despite an excess of available C.

  3. Exploring the Influence of Smallholders' Perceptions Regarding Water Availability on Crop Choice and Water Allocation Through Socio-Hydrological Modeling

    NASA Astrophysics Data System (ADS)

    Kuil, L.; Evans, T.; McCord, P. F.; Salinas, J. L.; Blöschl, G.

    2018-04-01

    While it is known that farmers adopt different decision-making behaviors to cope with stresses, it remains challenging to capture this diversity in formal model frameworks that are used to advance theory and inform policy. Guided by cognitive theory and the theory of bounded rationality, this research develops a novel, socio-hydrological model framework that can explore how a farmer's perception of water availability impacts crop choice and water allocation. The model is informed by a rich empirical data set at the household level collected during 2013 in Kenya's Upper Ewaso Ng'iro basin that shows that the crop type cultivated is correlated with water availability. The model is able to simulate this pattern and shows that near-optimal or "satisficing" crop patterns can emerge also when farmers were to make use of simple decision rules and have diverse perceptions on water availability. By focusing on farmer decision making it also captures the rebound effect, i.e., as additional water becomes available through the improvement of crop efficiencies it will be reallocated on the farm instead of flowing downstream, as a farmer will adjust his (her) water allocation and crop pattern to the new water conditions. This study is valuable as it is consistent with the theory of bounded rationality, and thus offers an alternative, descriptive model in addition to normative models. The framework can be used to understand the potential impact of climate change on the socio-hydrological system, to simulate and test various assumptions regarding farmer behavior and to evaluate policy interventions.

  4. 33 CFR 328.5 - Changes in limits of waters of the United States.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OF THE ARMY, DEPARTMENT OF DEFENSE DEFINITION OF WATERS OF THE UNITED STATES § 328.5 Changes in... drainage may remove an area from waters of the United States. Man-made changes may affect the limits of...

  5. Nutrient availability and nutrient use efficiency in plants growing in the transition zone between land and water.

    PubMed

    Cavalli, G; Baattrup-Pedersen, A; Riis, T

    2016-03-01

    The transition zone between terrestrial and freshwater habitats is highly dynamic, with large variability in environmental characteristics. Here, we investigate how these characteristics influence the nutritional status and performance of plant life forms inhabiting this zone. Specifically, we hypothesised that: (i) tissue nutrient content differs among submerged, amphibious and terrestrial species, with higher content in submerged species; and (ii) PNUE gradually increases from submerged over amphibious to terrestrial species, reflecting differences in the availability of N and P relative to inorganic C across the land-water ecotone. We found that tissue nutrient content was generally higher in submerged species and C:N and C:P ratios indicated that content was limiting for growth for ca. 20% of plant individuals, particularly those belonging to amphibious and terrestrial species groups. As predicted, the PNUE increased from submerged over amphibious to terrestrial species. We suggest that this pattern reflects that amphibious and terrestrial species allocate proportionally more nutrients into processes of importance for photosynthesis at saturating CO2 availability, i.e. enzymes involved in substrate regeneration, compared to submerged species that are acclimated to lower availability of CO2 in the aquatic environment. Our results indicate that enhanced nutrient loading may affect relative abundance of the three species groups in the land-water ecotone of stream ecosystems. Thus, species of amphibious and terrestrial species groups are likely to benefit more from enhanced nutrient availability in terms of faster growth compared to aquatic species, and that this can be detrimental to aquatic species growing in the land-water ecotone, e.g. Ranunculus and Callitriche. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Influences of climate change on water resources availability in Jinjiang Basin, China.

    PubMed

    Sun, Wenchao; Wang, Jie; Li, Zhanjie; Yao, Xiaolei; Yu, Jingshan

    2014-01-01

    The influences of climate change on water resources availability in Jinjiang Basin, China, were assessed using the Block-wise use of the TOPmodel with the Muskingum-Cunge routing method (BTOPMC) distributed hydrological model. The ensemble average of downscaled output from sixteen GCMs (General Circulation Models) for A1B emission scenario (medium CO2 emission) in the 2050s was adopted to build regional climate change scenario. The projected precipitation and temperature data were used to drive BTOPMC for predicting hydrological changes in the 2050s. Results show that evapotranspiration will increase in most time of a year. Runoff in summer to early autumn exhibits an increasing trend, while in the rest period of a year it shows a decreasing trend, especially in spring season. From the viewpoint of water resource availability, it is indicated that it has the possibility that water resources may not be sufficient to fulfill irrigation water demand in the spring season and one possible solution is to store more water in the reservoir in previous summer.

  7. Influences of Climate Change on Water Resources Availability in Jinjiang Basin, China

    PubMed Central

    Wang, Jie; Li, Zhanjie; Yao, Xiaolei

    2014-01-01

    The influences of climate change on water resources availability in Jinjiang Basin, China, were assessed using the Block-wise use of the TOPmodel with the Muskingum-Cunge routing method (BTOPMC) distributed hydrological model. The ensemble average of downscaled output from sixteen GCMs (General Circulation Models) for A1B emission scenario (medium CO2 emission) in the 2050s was adopted to build regional climate change scenario. The projected precipitation and temperature data were used to drive BTOPMC for predicting hydrological changes in the 2050s. Results show that evapotranspiration will increase in most time of a year. Runoff in summer to early autumn exhibits an increasing trend, while in the rest period of a year it shows a decreasing trend, especially in spring season. From the viewpoint of water resource availability, it is indicated that it has the possibility that water resources may not be sufficient to fulfill irrigation water demand in the spring season and one possible solution is to store more water in the reservoir in previous summer. PMID:24701192

  8. Lake-level variability and water availability in the Great Lakes

    USGS Publications Warehouse

    Wilcox, Douglas A.; Thompson, Todd A.; Booth, Robert K.; Nicholas, J.R.

    2007-01-01

    In this report, we present recorded and reconstructed (pre-historical) changes in water levels in the Great Lakes, relate them to climate changes of the past, and highlight major water-availability implications for storage, coastal ecosystems, and human activities. 'Water availability,' as conceptualized herein, includes a recognition that water must be available for human and natural uses, but the balancing of how much should be set aside for which use is not discussed. The Great Lakes Basin covers a large area of North America. The lakes capture and store great volumes of water that are critical in maintaining human activities and natural ecosystems. Water enters the lakes mostly in the form of precipitation and streamflow. Although flow through the connecting channels is a primary output from the lakes, evaporation is also a major output. Water levels in the lakes vary naturally on timescales that range from hours to millennia; storage of water in the lakes changes at the seasonal to millennial scales in response to lake-level changes. Short-term changes result from storm surges and seiches and do not affect storage. Seasonal changes are driven by differences in net basin supply during the year related to snowmelt, precipitation, and evaporation. Annual to millennial changes are driven by subtle to major climatic changes affecting both precipitation (and resulting streamflow) and evaporation. Rebounding of the Earth's surface in response to loss of the weight of melted glaciers has differentially affected water levels. Rebound rates have not been uniform across the basin, causing the hydrologic outlet of each lake to rise in elevation more rapidly than some parts of the coastlines. The result is a long-term change in lake level with respect to shoreline features that differs from site to site. The reconstructed water-level history of Lake Michigan-Huron over the past 4,700 years shows three major high phases from 2,300 to 3,300, 1,100 to 2,000, and 0 to 800

  9. Forests in a water limited world under climate change

    Treesearch

    C. Mátyás; G. Sun

    2014-01-01

    The debate on ecological and climatic benefits of planted forests at the sensitive dry edge of the closed forest belt (i.e. at the ‘xeric limits’) is still unresolved. Forests sequester atmospheric carbon dioxide, accumulate biomass, control water erosion and dust storms, reduce river sedimentation, and mitigate small floods. However, planting trees in areas previously...

  10. 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

  11. Shifting species interactions in terrestrial dryland ecosystems under altered water availability and climate change.

    PubMed

    McCluney, Kevin E; Belnap, Jayne; Collins, Scott L; González, Angélica L; Hagen, Elizabeth M; Nathaniel Holland, J; Kotler, Burt P; Maestre, Fernando T; Smith, Stanley D; Wolf, Blair O

    2012-08-01

    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

  12. Dynamic response of plant chlorophyll fluorescence to light, water and nutrient availability

    USDA-ARS?s Scientific Manuscript database

    Water deficit limits net photosynthesis (Anet) and decreases crop yields. An important challenge for basic and applied research is to establish a rigorous landscape-scale indicator of Anet. Chlorophyll fluorescence (ChF) can be used at the field scale as an indirect measure of Anet in both healthy a...

  13. Reassessment of Ground-Water Recharge and Simulated Ground-Water Availability for the Hawi Area of North Kohala, Hawaii

    USGS Publications Warehouse

    Oki, Delwyn S.

    2002-01-01

    An estimate of ground-water availability in the Hawi area of north Kohala, Hawaii, is needed to determine whether ground-water resources are adequate to meet future demand within the area and other areas to the south. For the Hawi area, estimated average annual recharge from infiltration of rainfall, fog drip, and irrigation is 37.5 million gallons per day from a daily water budget. Low and high annual recharge estimates for the Hawi area that incorporate estimated uncertainty are 19.9 and 55.4 million gallons per day, respectively. The recharge estimates from this study are lower than the recharge of 68.4 million gallons per day previously estimated from a monthly water budget. Three ground-water models, using the low, intermediate, and high recharge estimates (19.9, 37.5, and 55.4 million gallons per day, respectively), were developed for the Hawi area to simulate ground-water levels and discharges for the 1990?s. To assess potential ground-water availability, the numerical ground-water flow models were used to simulate the response of the freshwater-lens system to withdrawals at rates in excess of the average 1990?s withdrawal rates. Because of uncertainty in the recharge estimate, estimates of ground-water availability also are uncertain. Results from numerical simulations indicate that for appropriate well sites, depths, and withdrawal rates (1) for the low recharge estimate (19.9 million gallons per day) it may be possible to develop an additional 10 million gallons per day of fresh ground water from the Hawi area and maintain a freshwater-lens thickness of 160 feet near the withdrawal sites, (2) for the intermediate recharge estimate (37.5 million gallons per day) it may be possible to develop an additional 15 million gallons per day of fresh ground water from the Hawi area and maintain a freshwater-lens thickness of 190 feet near the withdrawal sites, and (3) for the high recharge estimate (55.4 million gallons per day) it may be possible to develop at

  14. Availability of Ground-water in Marion County, Indiana

    USGS Publications Warehouse

    Meyer, William R.; Reussow, J.P.; Gillies, D.C.; Shampine, W.J.

    1975-01-01

    A series of model experiments were carried out to test the capacity of the aquifers to sustain increases in pumpage. In all of these, a new equilibrium was established within 6 years of simulated pumpage. In two of these experiments, water levels in the discharging wells were allowed to draw down to approximately half of the saturated thickness of the glacial-outwash aquifer. At this drawdown limit, the total discharge of wells in the system was found to be 59 million gallons per day (2.6 cubic second) assuming that the streams were fully connected to the upper third of the glacial-outwash aquifer. In two other experiments, discharging wells were allowed to drawdown an average of two-thirds of the saturated thickness of the glacial-outwash aquifer. At this limit, the total discharge was found to be 72 million gallons per day (3.2 cubic metres per second) using the conservative stream-aquifer connection, and 103 million gallons per day (4.5 cubic metres per second) assuming a full connection. Some dewatering of the aquifer was associated with the 72 million gallons per day (3.2 cubic metres per second) discharge. In all experiments, the amount that could be pumped from the confined aquifers without disturbing existing domestic wells was found to be small.

  15. When vegetation change alters ecosystem water availability.

    PubMed

    Scott, Russell L; Huxman, Travis E; Barron-Gafford, Greg A; Darrel Jenerette, G; Young, Jessica M; Hamerlynck, Erik P

    2014-07-01

    The combined effects of vegetation and climate change on biosphere-atmosphere water vapor (H2 O) and carbon dioxide (CO2 ) exchanges are expected to vary depending, in part, on how biotic activity is controlled by and alters water availability. This is particularly important when a change in ecosystem composition alters the fractional covers of bare soil, grass, and woody plants so as to influence the accessibility of shallower vs. deeper soil water pools. To study this, we compared 5 years of eddy covariance measurements of H2 O and CO2 fluxes over a riparian grassland, shrubland, and woodland. In comparison with the surrounding upland region, groundwater access at the riparian sites increased net carbon uptake (NEP) and evapotranspiration (ET), which were sustained over more of the year. Among the sites, the grassland used less of the stable groundwater resource, and increasing woody plant density decoupled NEP and ET from incident precipitation (P), resulting in greater exchange rates that were less variable year to year. Despite similar gross patterns, how groundwater accessibility affected NEP was more complex than ET. The grassland had higher respiration (Reco ) costs. Thus, while it had similar ET and gross carbon uptake (GEP) to the shrubland, grassland NEP was substantially less. Also, grassland carbon fluxes were more variable due to occasional flooding at the site, which both stimulated and inhibited NEP depending upon phenology. Woodland NEP was large, but surprisingly similar to the less mature, sparse shrubland, even while having much greater GEP. Woodland Reco was greater than the shrubland and responded strongly and positively to P, which resulted in a surprising negative NEP response to P. This is likely due to the large accumulation of carbon aboveground and in the surface soil. These long-term observations support the strong role that water accessibility can play when determining the consequences of ecosystem vegetation change. © 2013 John Wiley

  16. Limit on rotational energy available to excite Jovian aurora

    NASA Technical Reports Server (NTRS)

    Eviatar, A.; Siscoe, G. L.

    1980-01-01

    There is a fundamental relationship between the power that is extracted from Jupiter's rotation to drive magnetospheric processes and the rate at which mass is injected into the Io plasma torus. Half of this power is consumed by bulk motion of the plasma and the other half represents an upper limit on the energy from rotation available for dissipation and in particular to excite the Jovian aurora. Since the rotation of the planet is the only plausible source of energy, the power inferred from the observed auroral intensities requires a plasma injection rate of 2.6 x 10 to the 29th AMU/sec or greater. This in turn leads to a residence time of a torus particle of 48 days or less. These results raise doubts about the applicability of equilibrium thermodynamics to the determination of plasma parameters in the Io torus.

  17. 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.

  18. Water Availability Indices – A Literature Review

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

    Xu, Hui; Wu, May M.

    Fresh water is a critical resource for humanity and the ecosystem. In general, water resources can be partitioned into two major categories: blue water and green water (Falkenmark and Rockström 2006). Precipitation that runs off or percolates into the deep aquifer is defined as blue water, and precipitation that filtrates into soil, which eventually returns to the atmosphere as evaporation, is called green water (Hoekstra et al. 2011). For human purposes, green water is almost exclusively used for agricultural production, but blue water can be used for multiple competing sectors, such as irrigation and municipal water.

  19. Can rainfed agriculture adapt to uncertainty in availability of water in Indus Basin?

    NASA Astrophysics Data System (ADS)

    Jutla, A.; Sen, S.

    2015-12-01

    Understanding impacts of hydrological and climatological functions under changing climate on regional floods, droughts as well as agricultural commodities remain a serious challenge in tropical agricultural basins. These "tropical agricultural basins" are regions where: (i) the understanding on hydrologic functions (such as precipitation, soil moisture, evapotranspiration, surface runoff, vegetation) are not well established; (ii) increasing population is at the convergence of rural and urban boundaries; (iii) resilience and sustainability of the water resources under different climatic conditions is unknown; and, (iv) agriculture is the primary occupation for majority of the population. More than 95% of the farmed lands in tropical regions are rainfed and 60% of total agricultural production in South Asia relying on seasonal rainfall. Tropical regions frequently suffer from unexpected droughts and sudden flash floods, resulting in massive losses in human lives and affecting regional economy. Prediction of frequency, intensity and magnitude of floods in tropical regions is still a subject of debate and research. A clear example is from the massive floods in the Eastern Indus River in July 2010 that submerged 17 million acre of fertile cropland. Yet, seasonal droughts, such as 2014 rain deficits in Indus Basin, had no effects on annual crop yields - thus creating a paradox. Large amounts of groundwater is being used to supplement water needs for crops during drought conditions, leading to oversubscription of natural aquifers. Key reason that rainfed agriculture is relying heavily on groundwater is because of the uncertainty in timing and distribution of precipitation in the tropical regions, where such data are not routinely collected as well as the basins are transnational, thus limiting sharing of data. Assessment of availability of water for agricultural purposes a serious challenge in tropical regions. This study will provide a framework for using multi

  20. Availability of ground water in the lower Pawcatuck River basin, Rhode Island

    USGS Publications Warehouse

    Gonthier, Joseph B.; Johnston, Herbert E.; Malmberg, Glenn T.

    1974-01-01

    The lower Pawcatuck River basin in southwestern Rhode Island is an area of about 169 square miles underlain by crystalline bedrock over which lies a relatively thin mantle of glacial till and stratified drift. Stratified drift, consisting dominantly of sand and gravel, occurs in irregularly shaped linear deposits that are generally less than a mile wide and less than 125 feet thick; these deposits are found along the Pawcatuck River, its tributaries, and abandoned preglacial channels. Deposits of stratified sand and gravel constitute the principal aquifer in the lower Pawcatuck basin and the only one capable of sustaining yields of 100 gallons per minute or more to individual wells. Water available for development in this aquifer consists of water in storage--potential ground-water runoff to streams--plus infiltration that can be induced from streams. Minimum annual ground-water runoff from the sand and gravel aquifer is calculated to be at least 1.17 cubic feet per second per square mile, or 0.76 million gallons per day per square mile. Potential recharge by induced infiltration is estimated to range from about 250 to 600 gallons per day per linear foot of streambed for the principal streams. In most areas, induced infiltration from streams constitutes the major source of water potentially available for development by wells. Because subsurface hydraulic connection in the sand and gravel aquifer is poor in several places, the deposits are conveniently divisible into several ground-water reservoirs. The potential yield from five of the most promising ground-water reservoirs is evaluated by means of mathematical models. Results indicate that continuous withdrawals ranging from 1.3 to 10.3 million gallons per day, and totaling 31 million gallons per day, are obtainable from these reservoirs. Larger yields may be recovered by different well placement, spacing, construction and development, pumping practice, and so forth. Withdrawals at the rates indicated will reduce

  1. Distribution and Availability of State and Areawide Water Quality Reports in Oklahoma Libraries.

    ERIC Educational Resources Information Center

    McClure, Charles R.; Million, Anne

    This report examines the distribution and availability of water quality reports in the state of Oklahoma. Based on legislation from the Clean Water Act and regulations from the Environmental Protection Agency's "Public Participation Handbook for Water Quality Management," depository libraries must be established to provide citizen access to…

  2. 40 CFR 442.23 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of best available technology economically achievable (BAT). 442.23 Section 442.23 Protection of... (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BAT: Limitations...

  3. 40 CFR 442.23 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of best available technology economically achievable (BAT). 442.23 Section 442.23 Protection of... (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BAT: Limitations...

  4. The bacteriological quality of different brands of bottled water available to consumers in Ile-Ife, south-western Nigeria.

    PubMed

    Igbeneghu, Oluwatoyin A; Lamikanra, Adebayo

    2014-11-28

    The upsurge in the demand for bottled water has prompted the interest of many manufacturers in the production of bottled water and very many water bottling companies are therefore involved in its production. These range from large scale multinational companies to medium scale business enterprises, institutional and government business investment companies as well as small scale entrepreneurs. There is however little information on the comparative quality of bottled water brands produced by different classes of water bottling companies in Nigeria. This study was undertaken to determine the bacteriological quality of brands of bottled water available to consumers in Ile-Ife. Forty-three samples of bottled water comprising of three batches each of thirteen bottled water brands and two batches of two brands were purchased and analyzed for total bacterial count, presence of coliform and the presence of other bacterial indicators of drinking water quality. Only 67.4% of the water samples representing the products of 10 companies or 66.7% of the brands had heterotrophic counts within the acceptable limits. Coliforms present in 100 ml of water were detected in 26.7% of the bottled water brands. Other indicator organisms detected included Staphylococci isolated from 27.9% of the samples (33.3% of the brands) and specifically Staphylococcus aureus found in four brands constituting 14% of the samples. Pseudomonas strains were consistently detected in consecutive batches of three brands of the water samples. Bottled water samples produced by the large scale multinational producers were of acceptable bacteriological quality unlike those produced by most small companies. There is need for a greater control of water bottling processes carried out by commercial bottled water producers in Nigeria.

  5. Reaction limits in knallgas saturated with water vapor. Progress report

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

    Adler, L.B.; Hobaica, E.C.; Luker, J.A.

    1957-12-10

    The basic objective of this research investigation is to determine the reactive limits of stoichiometric hydrogen-oxygen mixtures (knallgas) saturated with water vapor. In order to properly define these limits the effect of the following parameters on reaction limits are being investigated: (A) source of ignition; (B) reactor geometry or surface to volume ratio; and (C) density of the initial mixture. At the time of preparation of this progress report two series of runs had been completed. At 100/sup 0/C reactive limits have been investigated in an eight-foot tube of 0.957 inch internal diameter using constant energy spark ignition. For thismore » series the composition range studied was 2.6 to 76.7 mole percent knallgas. At 200/sup 0/C reactive limits have been investigated in a seven and a half-foot tube of 0.434 inch internal diameter using hot wire ignition. The composition range studied was 12.8 to 61 mole percent knallgas.« less

  6. Modeling of Soil Water Availability for Agricultural Planning at Pelaga Village, Badung Regency, Bali, Indonesia

    NASA Astrophysics Data System (ADS)

    Suyarto, R.; Sunarta, I. N.; Wiyanti; Padmayani, N. K. H.

    2017-12-01

    Pelaga Village is located in Badung regency which has the advantage in agriculture with the cultivation of coffee plants, oranges, carrots, cabbage, and chili. The physical condition of Pelaga Village which has high rainfall, bumpy areas, and sandy-sandy ground texture causes air to air to be available for plants. Based on these questions then conducted a study to determine the comparison between the available water and water requirement for agriculture. Available water was difference field capacity and permanent wilting point method and crop water requirement was using Blaney-Criddle method. The results from this research was deficit between available air and crop water requirements. Available water was 12,12% and crop water requirement in initial stage, dev. Stage, mid-season stage, and late season stage respectively, coffee 11.28%, 24.19%, 35.49%, 29.04%; cabbage 19.58%, 19.58%, 33.10%, 27.74%: carrot 14.82%, 28.61%, 28.61%, 27.95%: Orange 14.82%, 28.61%, 28.61%, 27.23%; chili, 17.37%,17.37%, 34.80%, 30.46%. Soil management that must be done is by short-term land management by sprinkling long-term soil management by means of organic material valuation, irrigation making, and terracing making.

  7. A model for evaluating effects of climate, water availability, and water management on wetland impoundments--a case study on Bowdoin, Long Lake, and Sand Lake National Wildlife Refuges

    USGS Publications Warehouse

    Tangen, Brian A.; Gleason, Robert A.; Stamm, John F.

    2013-01-01

    Many wetland impoundments managed by the U.S. Fish and Wildlife Service (USFWS) National Wildlife Refuge System throughout the northern Great Plains rely on rivers as a primary water source. A large number of these impoundments currently are being stressed from changes in water supplies and quality, and these problems are forecast to worsen because of projected changes to climate and land use. For example, many managed wetlands in arid regions have become degraded owing to the long-term accumulation of salts and increased salinity associated with evapotranspiration. A primary goal of the USFWS is to provide aquatic habitats for a diversity of waterbirds; thus, wetland managers would benefit from a tool that facilitates evaluation of wetland habitat quality in response to current and anticipated impacts of altered hydrology and salt balances caused by factors such as climate change, water availability, and management actions. A spreadsheet model that simulates the overall water and salinity balance (WSB model) of managed wetland impoundments is presented. The WSB model depicts various habitat metrics, such as water depth, salinity, and surface areas (inundated, dry), which can be used to evaluate alternative management actions under various water-availability and climate scenarios. The WSB model uses widely available spreadsheet software, is relatively simple to use, relies on widely available inputs, and is readily adaptable to specific locations. The WSB model was validated using data from three National Wildlife Refuges with direct and indirect connections to water resources associated with rivers, and common data limitations are highlighted. The WSB model also was used to conduct simulations based on hypothetical climate and management scenarios to demonstrate the utility of the model for evaluating alternative management strategies and climate futures. The WSB model worked well across a range of National Wildlife Refuges and could be a valuable tool for USFWS

  8. 76 FR 62061 - Clean Water Act Section 303(d): Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-06

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9475-4] Clean Water Act Section 303(d): Availability of List... three waterbodies. These three waterbodies were added by EPA because the applicable numeric water... be obtained at EPA Region 6's Web site at http://www.epa.gov/region6/water/npdes/tmdl/index.htm...

  9. Ozone risk assessment in three oak species as affected by soil water availability.

    PubMed

    Hoshika, Yasutomo; Moura, Barbara; Paoletti, Elena

    2018-03-01

    To derive ozone (O 3 ) dose-response relationships for three European oak species (Quercus ilex, Quercus pubescens, and Quercus robur) under a range of soil water availability, an experiment was carried out with 2-year-old potted seedlings exposed to three levels of water availability in the soil and three levels of O 3 pollution for one growing season in an ozone free-air controlled exposure (FACE) facility. Total biomass losses were estimated relative to a hypothetical clean air at the pre-industrial age, i.e., at 10 ppb as daily average (M24). A stomatal conductance model was parameterized with inputs from the three species for calculating the stomatal O 3 flux. Exposure-based (M24, W126, and AOT40) and flux-based (phytotoxic O 3 dose (POD) 0-3 ) dose-response relationships were estimated and critical levels (CL) were calculated for a 5% decline of total biomass. Results show that water availability can significantly affect O 3 risk assessment. In fact, dose-response relationships calculated per individual species at each water availability level resulted in very different CLs and best metrics. In a simplified approach where species were aggregated on the basis of their O 3 sensitivity, the best metric was POD 0.5 , with a CL of 6.8 mmol m -2 for the less O 3 -sensitive species Q. ilex and Q. pubescens and of 3.5 mmol m -2 for the more O 3 -sensitive species Q. robur. The performance of POD 0 , however, was very similar to that of POD 0.5 , and thus a CL of 6.9 mmol m -2 POD 0 and 3.6 mmol m -2 POD 0 for the less and more O 3 -sensitive oak species may be also recommended. These CLs can be applied to oak ecosystems at variable water availability in the soil. We conclude that POD y is able to reconcile the effects of O 3 and soil water availability on species-specific oak productivity.

  10. Concepts for national assessment of water availability and use

    USGS Publications Warehouse

    ,

    2002-01-01

    In response to a directive from Congress to the U.S. Geological Survey to 'prepare a report describing the scope and magnitude of the efforts needed to provide periodic assessments of the status and trends in the availability and use of freshwater resources,' of the United States, a program is proposed to develop and report on indicators of the status and trends in storage volume, flow rates, and uses of water nationwide. This program would be analogous to the task of other Federal statistical programs that produce and regularly update indicator variables that describe economic, demographic, and health conditions of the Nation. The assessment also would provide regional estimates of recharge, evapotranspiration, interbasin transfers, and other components of the water cycle.

  11. Aquifer characteristics, water availability, and water quality of the Quaternary aquifer, Osage County, northeastern Oklahoma, 2001-2002

    USGS Publications Warehouse

    Mashburn, Shana L.; Cope, Caleb C.; Abbott, Marvin M.

    2003-01-01

    Additional sources of water are needed on the Osage Reservation for future growth and development. The Quaternary aquifer along the Arkansas River in the Osage Reservation may represent a substantial water resource, but limited amounts of hydrogeologic data were available for the aquifer. The study area is about 116 square miles of the Quaternary aquifer in the Arkansas River valley and the nearby upland areas along the Osage Reservation. The study area included the Arkansas River reach downstream from Kaw Lake near Ponca City, Oklahoma to upstream from Keystone Lake near Cleveland, Oklahoma. Electrical conductivity logs were produced for 103 test holes. Water levels were determined for 49 test holes, and 105 water samples were collected for water-quality field analyses at 46 test holes. Water-quality data included field measurements of specific conductance, pH, water temperature, dissolved oxygen, and nitrate (nitrite plus nitrate as nitrogen). Sediment cores were extracted from 20 of the 103 test holes. The Quaternary aquifer consists of alluvial and terrace deposits of sand, silt, clay, and gravel. The measured thickness of the alluvium ranged from 13.7 to 49.8 feet. The measured thickness of the terrace sediments ranged from 7 to 93.8 feet. The saturated thickness of all sediments ranged from 0 to 38.2 feet with a median of 24.8 feet. The weighted-mean grain size for cores from the alluvium ranged from 3.69 to 0.64 f, (0.08- 0.64 millimeter), and ranged from 4.02 to 2.01 f (0.06-0.25 millimeter) for the cores from terrace deposits. The mean of the weighted-mean grain sizes for cores from the alluvium was 1.67 f (0.31 millimeter), and the terrace deposits was 2.73 f (0.15 millimeter). The hydraulic conductivity calculated from grain size of the alluvium ranged from 2.9 to 6,000 feet per day and of the terrace deposits ranged from 2.9 to 430 feet per day. The calculated transmissivity of the alluvium ranged from 2,000 to 26,000 feet squared per day with a median

  12. Aggregating available soil water holding capacity data for crop yield models

    NASA Technical Reports Server (NTRS)

    Seubert, C. E.; Daughtry, C. S. T.; Holt, D. A.; Baumgardner, M. F.

    1984-01-01

    The total amount of water available to plants that is held against gravity in a soil is usually estimated as the amount present at -0.03 MPa average water potential minus the amount present at -1.5 MPa water potential. This value, designated available water-holding capacity (AWHC), is a very important soil characteristic that is strongly and positively correlated to the inherent productivity of soils. In various applications, including assessing soil moisture status over large areas, it is necessary to group soil types or series as to their productivity. Current methods to classify AWHC of soils consider only total capacity of soil profiles and thus may group together soils which differ greatly in AWHC as a function of depth in the profile. A general approach for evaluating quantitatively the multidimensional nature of AWHC in soils is described. Data for 902 soil profiles, representing 184 soil series, in Indiana were obtained from the Soil Characterization Laboratory at Purdue University. The AWHC for each of ten 150-mm layers in each soil was established, based on soil texture and parent material. A multivariate clustering procedure was used to classify each soil profile into one of 4, 8, or 12 classes based upon ten-dimensional AWHC values. The optimum number of classes depends on the range of AWHC in the population of oil profiles analyzed and on the sensitivity of a crop to differences in distribution of water within the soil profile.

  13. Environmental and socioeconomic benefits and limitations of water harvesting techniques in semiarid regions

    NASA Astrophysics Data System (ADS)

    Díaz-Pereira, Elvira; Asunción Romero-Díaz, María; de Vente, Joris

    2016-04-01

    Under climate change, sustainable management of soil and water resources is increasingly important, especially in rainfed agroecosystems of semiarid environments. Water harvesting refers to a range of techniques for the collection and management of flood or rainwater for domestic and agricultural use and for water retention in natural ecosystems. Water harvesting represents a good example of sustainable management of water resources that contribute to water and food security. However, there are often environmental and socioeconomic constraints for implementation of water harvesting techniques, so each condition asks for a specific solution. Here we aim to highlight the environmental and socioeconomic benefits, requirements and limitations of different water harvesting techniques and to characterize their implications for provisioning, regulating, supporting, and cultural ecosystem services. We reviewed 62 water harvesting techniques for semiarid regions extracted from the WOCAT (World Overview of Conservation Approaches and Technologies) database. We discuss aspects related to: i) human and environmental characteristics, ii) cost-benefit ratio during implementation and maintenance phases, iii) socioeconomic and environmental impacts at local and regional scales, and, iv) impacts on ecosystem services. Our review reveals that water harvesting represents very diverse methods of collecting and managing floodwaters and surface runoff. We grouped techniques as 'floodwater harvesting', 'macro-catchment water harvesting', 'micro-catchment water harvesting', and 'rooftop and courtyard' water harvesting. Almost half of all technologies originates from traditional knowledge. The implementation of water harvesting is generally positive on the short-term, to very positive on the long-term, while its maintenance is very positive at short and long-term. However, perception depends on the type of water harvesting and local conditions. Most relevant socioeconomic benefits from

  14. Nutrient availability constrains the hydraulic architecture and water relations of savannah trees.

    Treesearch

    S.J. Bucci; F.G. Scholz; G. Goldstein; F.C. Meinzer; A.C. Franco; P.I. Campanello; R. Villalobos-Vega; M. Bustamante; F. Miralles-Wilhelm

    2006-01-01

    Several plant functional traits were studied in five dominant woody savanna species in a Brazilian savanna to determine whether removal of nutrient limitations has an effect on carbon allocation, water relations, and hydraulic architecture. Four treatments consisting of a control, and nitrogen (N), phosphorus (P), and N plus P additions were maintained for 5 years....

  15. Investigation of fundamental limits to beam brightness available from photoinjectors

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

    Bazarov, Ivan

    2015-07-09

    The goal of this project was investigation of fundamental limits to beam brightness available from photoinjectors. This basic research in accelerator physics spanned over 5 years aiming to extend the fundamental understanding of high average current, low emittance sources of relativistic electrons based on photoemission guns, a necessary prerequisite for a new generation of coherent X-ray synchrotron radiation facilities based on continuous duty superconducting linacs. The program focused on two areas critical to making advances in the electron source performance: 1) the physics of photocathodes for the production of low emittance electrons and 2) control of space charge forces inmore » the immediate vicinity to the cathode via 3D laser pulse shaping.« less

  16. Availability of water affects renewal of tissues in migratory blackcaps during stopover.

    PubMed

    Mizrahy, Ortal; Bauchinger, Ulf; Aamidor, Sarah E; McWilliams, Scott R; Pinshow, Berry

    2011-09-01

    Migrating blackcaps (Sylvia atricapilla) were used to test the predictions that (1) the rebuilding of the digestive tract, as reflected by mass-specific consumption of food on the first 2-3 days of a stopover, is faster in birds with access to drinking water than in birds without, and (2) that adipose tissue and pectoral muscles grow faster and to a greater extent in birds with unlimited access to water. We simulated migratory stopover in two experiments. In Experiment I, each of 31 birds was randomly assigned to one of three experimental groups for 6 days. Along with mealworms (∼64% water) ad libitum, Group 1 received drinking water ad libitum; Group 2 had 0.5 h/day access to water; and Group 3 had no access to water. In Experiment II, 30 birds were offered a mixed diet for insectivorous birds (∼33% water) ad libitum for 6 days, while randomly assigned to two groups: (1) Water ad libitum-control; and (2) 30 min access to water twice a day. We measured lean mass and fat mass using dual energy X-ray absorptiometry, as well as body mass (m(b)), pectoral muscle index (PMI), and daily intake of food and water. Mean daily water intake was significantly different among the groups in both experiments. However, the availability of drinking water positively affected the rates of gain of lean and fat mass only in birds fed with the mixed, relatively dry diet. Furthermore, mass-specific daily food intake was affected by the availability of drinking water only in the mixed diet experiment, in which birds with unlimited access to drinking water reached an asymptote, 1 day earlier than birds in the water-restricted group. We suggest that in birds consuming diets with low water content, the lack of sufficient drinking water may result in slower rebuilding of the digestive tract, or may influence biochemical processes in the gut that result in slower growth of tissue. Although blackcaps obtained sufficient water from preformed and metabolic water to renew lost tissues when

  17. Plant roots use a patterning mechanism to position lateral root branches toward available water.

    PubMed

    Bao, Yun; Aggarwal, Pooja; Robbins, Neil E; Sturrock, Craig J; Thompson, Mark C; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L; Vernoux, Teva; Mooney, Sacha J; Bennett, Malcolm J; Dinneny, José R

    2014-06-24

    The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of tryptophan aminotransferase of Arabidopsis 1 and PIN-formed 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root.

  18. Middle-term Metropolitan Water Availability Index Assessment Based on Synergistic Potentials of Multi-sensor Data

    EPA Science Inventory

    The impact of recent drought and water pollution episodes results in an acute need to project future water availability to assist water managers in water utility infrastructure management within many metropolitan regions. Separate drought and water quality indices previously deve...

  19. Identification of the effective water availability from streamflows in the Zerafshan river basin, Central Asia

    NASA Astrophysics Data System (ADS)

    Olsson, Oliver; Gassmann, Matthias; Wegerich, Kai; Bauer, Melanie

    2010-09-01

    SummaryQuantitative estimates of the hydrologic effects of climate change are essential for understanding and solving potential transboundary water conflicts in the Zerafshan river basin, Central Asia. This paper introduces an identification of runoff generation processes and a detection of changes in hydrological regimes supporting Mann-Kendall trend analysis for streamflows. By this, the effective available and future water resources are identified for the Zerafshan. The results for the subbasins in the upper Zerafshan and for the reference station at the upper catchment outlet indicate that glacier melt is the most significant component of river runoff. The Mann-Kendall trend analysis confirms the regime analysis with the shift in the seasonality of the discharge. Furthermore, the results of the Kendall-Theil Robust Line for predicted long-term discharge trends show a decreasing annual discharge. The experience gained during this study emphasizes the fact that the summer flood, urgently required for the large irrigation projects downstream in Uzbekistan, is reduced and more water will be available in spring. Additionally, following the estimation of future discharges in 50 and 100 years the hydrological changes are affecting the seasonal water availability for irrigation. This analysis highlighted that water availability is decreasing and the timing of availability is changing. Hence, there will be more competition between upstream Tajikistan and downstream Uzbekistan. Planned projects within the basin might have to be reconsidered and the changed scenario of water availability needs to be properly taken into account for long-term basin scale water management.

  20. Marine chemical technology and sensors for marine waters: potentials and limits.

    PubMed

    Moore, Tommy S; Mullaugh, Katherine M; Holyoke, Rebecca R; Madison, Andrew S; Yücel, Mustafa; Luther, George W

    2009-01-01

    A significant need exists for in situ sensors that can measure chemical species involved in the major processes of primary production (photosynthesis and chemosynthesis) and respiration. Some key chemical species are O2, nutrients (N and P), micronutrients (metals), pCO2, dissolved inorganic carbon (DIC), pH, and sulfide. Sensors need to have excellent detection limits, precision, selectivity, response time, a large dynamic concentration range, low power consumption, robustness, and less variation of instrument response with temperature and pressure, as well as be free from fouling problems (biological, physical, and chemical). Here we review the principles of operation of most sensors used in marine waters. We also show that some sensors can be used in several different oceanic environments to detect the target chemical species, whereas others are useful in only one environment because of various limitations. Several sensors can be used truly in situ, whereas many others involve water brought into a flow cell via tubing to the analyzer in the environment or aboard ship. Multi-element sensors that measure many chemical species in the same water mass should be targeted for further development.

  1. Availability and quality of water from drift aquifers in Marshall, Pennington, Polk, and Red Lake counties, northwestern Minnesota

    USGS Publications Warehouse

    Lindgren, R.J.

    1996-01-01

    Water samples analyzed for nitrate had nitrate concentrations below the reporting limit (0.05 milligrams per liter) in 10 out of 23 wells. Two samples had nitrate concentrations greater than 10 milligrams per liter. Pesticide concentrations in water samples from 17 wells screened in unconfined and shallow confined aquifers were below or only slightly above laboratory reporting limits.

  2. Polder effects on sediment-to-soil conversion: water table, residual available water capacity, and salt stress interdependence.

    PubMed

    Radimy, Raymond Tojo; Dudoignon, Patrick; Hillaireau, Jean Michel; Deboute, Elise

    2013-01-01

    The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields.

  3. Root-zone temperature and water availability affect early root growth of planted longleaf pine

    Treesearch

    M.A. Sword

    1995-01-01

    Longleaf pine seedlings from three seed sources were exposed to three root-zone temperatures and three levels of water availability for 28 days. Root growth declined as temperature and water availability decreased. Root growth differed by seed source. Results suggest that subtle changes in the regeneration environment may influence early root growth of longleaf pine...

  4. Vegetative response to water availability on the San Carlos Apache Reservation

    USGS Publications Warehouse

    Petrakis, Roy; Wu, Zhuoting; McVay, Jason; Middleton, Barry R.; Dye, Dennis G.; Vogel, John M.

    2016-01-01

    On the San Carlos Apache Reservation in east-central Arizona, U.S.A., vegetation types such as ponderosa pine forests, pinyon-juniper woodlands, and grasslands have significant ecological, cultural, and economic value for the Tribe. This value extends beyond the tribal lands and across the Western United States. Vegetation across the Southwestern United States is susceptible to drought conditions and fluctuating water availability. Remotely sensed vegetation indices can be used to measure and monitor spatial and temporal vegetative response to fluctuating water availability conditions. We used the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived Modified Soil Adjusted Vegetation Index II (MSAVI2) to measure the condition of three dominant vegetation types (ponderosa pine forest, woodland, and grassland) in response to two fluctuating environmental variables: precipitation and the Standardized Precipitation Evapotranspiration Index (SPEI). The study period covered 2002 through 2014 and focused on a region within the San Carlos Apache Reservation. We determined that grassland and woodland had a similar moderate to strong, year-round, positive relationship with precipitation as well as with summer SPEI. This suggests that these vegetation types respond negatively to drought conditions and are more susceptible to initial precipitation deficits. Ponderosa pine forest had a comparatively weaker relationship with monthly precipitation and summer SPEI, indicating that it is more buffered against short-term drought conditions. This research highlights the response of multiple, dominant vegetation types to seasonal and inter-annual water availability. This research demonstrates that multi-temporal remote sensing imagery can be an effective tool for the large scale detection of vegetation response to adverse impacts from climate change and support potential management practices such as increased monitoring and management of drought-affected areas. Different

  5. Asynchronous Amazon forest canopy phenology indicates adaptation to both water and light availability

    NASA Astrophysics Data System (ADS)

    Jones, Matthew O.; Kimball, John S.; Nemani, Ramakrishna R.

    2014-12-01

    Amazon forests represent nearly half of all tropical vegetation biomass and, through photosynthesis and respiration, annually process more than twice the amount of estimated carbon (CO2) from fossil fuel emissions. Yet the seasonality of Amazon canopy cover, and the extent to which seasonal fluctuations in water availability and photosynthetically available radiation influence these processes, is still poorly understood. Implementing six remotely sensed data sets spanning nine years (2003-2011), with reported field and flux tower data, we show that southern equatorial Amazon forests exhibit a distinctive seasonal signal. Seasonal timing of water availability, canopy biomass growth and net leaf flush are asynchronous in regions with short dry seasons and become more synchronous across a west-to-east longitudinal moisture gradient of increasing dry season. Forest cover is responsive to seasonal disparities in both water and solar radiation availability, temporally adjusting net leaf flush to maximize use of these generally abundant resources, while reducing drought susceptibility. An accurate characterization of this asynchronous behavior allows for improved understanding of canopy phenology across contiguous tropical forests and their sensitivity to climate variability and drought.

  6. 77 FR 20020 - Clean Water Act Section 303(d): Availability of List Decisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9655-2] Clean Water Act Section 303(d): Availability of List Decisions AGENCY: Environmental Protection Agency. ACTION: Notice of availability. SUMMARY: This notice announces the availability of EPA's Responsiveness Summary Concerning EPA's November 30, 2011, Public Notice...

  7. Water availability at hospitals in low- and middle-income countries: implications for improving access to safe surgical care.

    PubMed

    Chawla, Sagar S; Gupta, Shailvi; Onchiri, Frankline M; Habermann, Elizabeth B; Kushner, Adam L; Stewart, Barclay T

    2016-09-01

    Although two billion people now have access to clean water, many hospitals in low- and middle-income countries (LMICs) do not. Lack of water availability at hospitals hinders safe surgical care. We aimed to review the surgical capacity literature and document the availability of water at health facilities and develop a predictive model of water availability at health facilities globally to inform targeted capacity improvements. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic search for surgical capacity assessments in LMICs in MEDLINE, PubMed, and World Health Organization Global Health Library was performed. Data regarding water availability were extracted. Data from these assessments and national indicator data from the World Bank (e.g., gross domestic product, total health expenditure, and percent of population with improved access to water) were used to create a predictive model for water availability in LMICs globally. Of the 72 records identified, 19 reported water availability representing 430 hospitals. A total of 66% of hospitals assessed had water availability (283 of 430 hospitals). Using these data, estimated percent of water availability in LMICs more broadly ranged from under 20% (Liberia) to over 90% (Bangladesh, Ghana). Less than two-thirds of hospitals providing surgical care in 19 LMICs had a reliable water source. Governments and nongovernmental organizations should increase efforts to improve water infrastructure at hospitals, which might aid in the provision of safe essential surgical care. Future research is needed to measure the effect of water availability on surgical care and patient outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Sino-US cooperation in water saving technologies

    USDA-ARS?s Scientific Manuscript database

    Both China and the United States face water availability problems that limit agricultural production and that are exacerbated by climate variability. Water availability is limited both in terms of quantity and quality with the impacts of drought and declining aquifers resulting in water restrictions...

  9. Relative controls of natural and socio-economic drivers on water availability over India: an exploratory modelling analysis

    NASA Astrophysics Data System (ADS)

    Deshmukh, A.; Singh, R.; Kumar, R.

    2017-12-01

    India, a water stressed nation with an estimated per capita water availability of 1500m3/year/person, is projected to surpass China in population to become the most populous country by 2022. This increasing population will further exacerbate the water stress, which will also vary due to climate and land use change. Here, we quantify the relative controls on per capita water availability from climatic, non-climatic and socio-economic factors. We achieve this by using several definitions of per capita water availability and accounting for virtual water trade transfer. Our exploratory analysis employs the recently developed probabilistic Budyko framework modified to account for inter-regional virtual water trade. We find that the Indo-Gangetic plains and Southeastern parts of India emerge as vulnerable regions where a growing population will lead to a drastic reduction in per capita water availability. The proposed framework can serve as a prototype for understanding the relative importance of socio-economic interventions versus water infrastructure or demand reduction investments.

  10. The impacts of irrigation with transferred and saline reclaimed water in the soil biological quality of two citrus species: Adaptations to low water availability

    NASA Astrophysics Data System (ADS)

    Bastida, Felipe; Abadía, Joaquín; García, Carlos; Torres, Irene; Ruiz Navarro, Antonio; José Alarcón, Juan; Nicolás, Emilio

    2017-04-01

    Mediterranean agroecosystems are limited by the availability of water and hence it is fundamental to find new water sources for sustainable agriculture in the face of climate change. Here, the effects of irrigation with water from different sources were analyzed in the soil microbial community and plant status of grapefruit and mandarin trees in a Mediterranean agro-ecosystem located in south-east of Spain. Four irrigation treatments were evaluated: i) water with an average electrical conductivity (EC) of 1.1 dS m-1 from the "Tagus-Segura" water-transfer canal (TW); ii) reclaimed water (EC = 3.21 dS m-1) from a wastewater-treatment-plant (RW); iii) irrigation with TW, except in the second stage of fruit development, when RW was applied (TWc); and iv) irrigation with RW except in the second stage, when TW was used (RWc). Phospholipid fatty acids indicated that microbial biomass was greater under grapefruit than under mandarin. In the case of grapefruit, TW showed a lower bacterial biomass than RW, RWc, and TWc, while RW showed the lowest values in the mandarin soil. In grapefruit soil, β-glucosidase and cellobiohydrolase activities, related to C cycling, were greater in RW and TWc than in TW and RWc. In mandarin soil, the greatest activity of these enzymes was found in TWc. The saline stress induced lower net photosynthesis (A) and stomatal conductance (gs) in plants of RW, RWc and TWc in comparison with TW. The annual use of reclaimed water or the combined irrigation with TWc positively influenced the soil biological quality of a grapefruit agro-ecosystem. Conversely, the mandarin soil community was more sensitive to the annual irrigation with RW.

  11. FLUORIDE CONTENT OF COMMERCIALLY AVAILABLE BOTTLED DRINKING WATER IN BANGKOK, THAILAND.

    PubMed

    Rirattanapong, Praphasri; Rirattanapong, Opas

    2016-09-01

    The use of bottled drinking water may be a source of fluoride and could be a risk factor for fluorosis among infants and young children. The aim of this study was to evaluate the fluoride content of commercially available bottled drinking water in Bangkok, Thailand. Forty-five water samples (15 samples of plain water and 30 samples of mineral water) were purchased from several supermarkets in Bangkok, Thailand. Three bottles of each water sample were purchased, and the fluoride content of each sample was measured twice using a combination fluoride-ion selective electrode. The average reading for each sample was then calculated. Data were analyzed by descriptive statistics. Differences between mineral and plain water samples were determined by Student’s t-test. The mean (±SD) fluoride content for all the water samples was 0.17 (±0.17) mg F/l (range: 0.01-0.89 mg F/l). Six brands (13%) tested stated the fluoride content on the label. The actual fluoride content in each of their brands varied little from the label. Eight samples (18%) had a fluoride content >0.3 mg F/l and two samples (4%) had a fluoride content >0.6 mg F/l. The mean mineral water fluoride concentration was significantly higher than the mean fluoride concentration of plain water (p=0.001). We found commercially sold bottled drinking water in Bangkok, Thailand contained varying concentrations of fluoride; some with high concentrations of fluoride. Health professions need to be aware this varying fluoride content of bottled drinking water and educate the parents of infants and small children about this when prescribing fluoride supplements. Consideration should be made to have fluoride content put on the label of bottled water especially among brands with a content >0.3 mg F/l.

  12. Polder Effects on Sediment-to-Soil Conversion: Water Table, Residual Available Water Capacity, and Salt Stress Interdependence

    PubMed Central

    Radimy, Raymond Tojo; Dudoignon, Patrick; Hillaireau, Jean Michel; Deboute, Elise

    2013-01-01

    The French Atlantic marshlands, reclaimed since the Middle Age, have been successively used for extensive grazing and more recently for cereal cultivation from 1970. The soils have acquired specific properties which have been induced by the successive reclaiming and drainage works and by the response of the clay dominant primary sediments, that is, structure, moisture, and salinity profiles. Based on the whole survey of the Marais Poitevin and Marais de Rochefort and in order to explain the mechanisms of marsh soil behavior, the work focuses on two typical spots: an undrained grassland since at least 1964 and a drained cereal cultivated field. The structure-hydromechanical profiles relationships have been established thanks to the clay matrix shrinkage curve. They are confronted to the hydraulic functioning including the fresh-to-salt water transfers and to the recording of tensiometer profiles. The CE1/5 profiles supply the water geochemical and geophysical data by their better accuracy. Associated to the available water capacity calculation they allow the representation of the parallel evolution of the residual available water capacity profiles and salinity profiles according to the plant growing and rooting from the mesophile systems of grassland to the hygrophile systems of drained fields. PMID:23990758

  13. Water and nitrogen availability co-control ecosystem CO2 exchange in a semiarid temperate steppe.

    PubMed

    Zhang, Xiaolin; Tan, Yulian; Li, Ang; Ren, Tingting; Chen, Shiping; Wang, Lixin; Huang, Jianhui

    2015-10-23

    Both water and nitrogen (N) availability have significant effects on ecosystem CO2 exchange (ECE), which includes net ecosystem productivity (NEP), ecosystem respiration (ER) and gross ecosystem photosynthesis (GEP). How water and N availability influence ECE in arid and semiarid grasslands is still uncertain. A manipulative experiment with additions of rainfall, snow and N was conducted to test their effects on ECE in a semiarid temperate steppe of northern China for three consecutive years with contrasting natural precipitation. ECE increased with annual precipitation but approached peak values at different precipitation amount. Water addition, especially summer water addition, had significantly positive effects on ECE in years when the natural precipitation was normal or below normal, but showed trivial effect on GEP when the natural precipitation was above normal as effects on ER and NEP offset one another. Nitrogen addition exerted non-significant or negative effects on ECE when precipitation was low but switched to a positive effect when precipitation was high, indicating N effect triggered by water availability. Our results indicate that both water and N availability control ECE and the effects of future precipitation changes and increasing N deposition will depend on how they can change collaboratively in this semiarid steppe ecosystem.

  14. 40 CFR 444.15 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 444.15 Section 444.15 Protection... (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BAT: Limitations...

  15. 40 CFR 444.15 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 444.15 Section 444.15 Protection... (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BAT: Limitations...

  16. 40 CFR 444.15 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 444.15 Section 444.15 Protection... (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this subpart must achieve the following effluent limitations representing the application of BAT: Limitations...

  17. Global pattern of trends in streamflow and water availability in a changing climate.

    PubMed

    Milly, P C D; Dunne, K A; Vecchia, A V

    2005-11-17

    Water availability on the continents is important for human health, economic activity, ecosystem function and geophysical processes. Because the saturation vapour pressure of water in air is highly sensitive to temperature, perturbations in the global water cycle are expected to accompany climate warming. Regional patterns of warming-induced changes in surface hydroclimate are complex and less certain than those in temperature, however, with both regional increases and decreases expected in precipitation and runoff. Here we show that an ensemble of 12 climate models exhibits qualitative and statistically significant skill in simulating observed regional patterns of twentieth-century multidecadal changes in streamflow. These models project 10-40% increases in runoff in eastern equatorial Africa, the La Plata basin and high-latitude North America and Eurasia, and 10-30% decreases in runoff in southern Africa, southern Europe, the Middle East and mid-latitude western North America by the year 2050. Such changes in sustainable water availability would have considerable regional-scale consequences for economies as well as ecosystems.

  18. Insights from a network of long-term measurements of biosphere-atmospheric exchanges of water vapor and carbon dioxide in a water-limited semiarid region

    NASA Astrophysics Data System (ADS)

    Scott, Russell; Biederman, Joel

    2017-04-01

    Around one-third of Earth's land surface is classified as semiarid, and carbon dioxide exchange in these regions has been shown to be an important regulator of both the trend and interannual variability of the terrestrial carbon sink. Fifteen years ago, when we began making measurements of biosphere-atmospheric exchanges of energy, water vapor, and carbon dioxide using eddy covariance in southern Arizona USA, there was paucity of semiarid observations in flux networks like AmeriFlux and EuroFlux. We started by establishing riparian sites across a woody plant encroachment gradient to quantify the productivity and consumptive plant water use along a iconic and ecologically important desert river. Soon thereafter, we added semiarid grassland, shrubland, and savanna sites that do not have access to groundwater in order to better understand how water limitation and changes in vegetation structure affect ecosystem productivity. Here, we highlight the value of multiyear, multisite flux data for addressing regional to global scale problems associated with groundwater pumping, land cover change, drought, and climate change. For the riparian sites, we find that ecosystem water availability is altered by vegetation structure such that ecosystems with more deeply rooted trees have higher productivity but at a cost of greater groundwater use. For the non-riparian sites, precipitation strongly controls ecosystem water availability and the resultant productivity, but differences in ecosystem structure impact water use efficiency due to the partitioning of evapotranspiration into its component sources. Also, the productivity at sites with more grass, and less woody, plants responds more quickly to precipitation fluctuations including long-term drought conditions. In semiarid regions, variability in water and carbon fluxes is much larger than in more mesic climes. Across our riparian and non-riparian sites, access to more stable groundwater reserves reduces variability in water and

  19. Role of soil sorption and microbial degradation on dissipation of mesotrione in plant-available soil water.

    PubMed

    Shaner, Dale; Brunk, Galen; Nissen, Scott; Westra, Phil; Chen, Wenlin

    2012-01-01

    Mesotrione is a carotenoid biosynthesis-inhibiting herbicide labeled for pre-emergence and postemergence weed control in corn production. Understanding the factors that influence the dissipation of mesotrione in soil and in the plant-available water (PAW) is important for the environmental fate assessment and optimal weed management practices. The present research investigated the role of soil properties and microbial activities on the interrelated sorption and degradation processes of mesotrione in four soils by direct measurements of PAW. We found that mesotrione bound to the soils time dependently, with approximately 14 d to reach equilibrium. The 24-h batch-slurry equilibrium experiments provided the sorption partition coefficient ranging from 0.26 to 3.53 L kg(-1), depending on soil organic carbon and pH. The dissipation of mesotrione in the soil-bound phase was primarily attributed to desorption to the PAW. Degradation in the PAW was rapid and primarily dependent on microbial actions, with half-degradation time (DT(50)) <3 d in all four soils tested. The rapid degradation in the PAW became rate limited by sorption as more available molecules were depleted in the soil pore water, resulting in a more slowed overall process for the total soil-water system (DT(50) <26 d). The dissipation of mesotrione in the PAW was due to microbial metabolism and time-dependent sorption to the soils. A coupled kinetics model calibrated with the data from the laboratory centrifugation technique provided an effective approach to investigate the interrelated processes of sorption and degradation in realistic soil moisture conditions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  20. 40 CFR 451.12 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 451.12 Section 451.12 Protection... technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing... of BAT: The limitations are the same as the corresponding limitations specified in § 451.11. ...

  1. 40 CFR 451.12 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 451.12 Section 451.12 Protection... technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing... of BAT: The limitations are the same as the corresponding limitations specified in § 451.11. ...

  2. 40 CFR 451.12 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 451.12 Section 451.12 Protection... technology economically achievable (BAT). Except as provided in 40 CFR 125.30 through 125.32, any existing... of BAT: The limitations are the same as the corresponding limitations specified in § 451.11. ...

  3. Cell and tissue dynamics of olive endocarp sclerification vary according to water availability.

    PubMed

    Hammami, Sofiene B M; Costagli, Giacomo; Rapoport, Hava F

    2013-12-01

    Endocarp developmental timing in drupe-type fruits, involving tissue expansion and sclerification processes, is increasingly used as marker for biological studies and crop management. In spite of its wide application, however, little is known regarding how these morphogenetic processes unfold or the factors that modify it. This study evaluates endocarp expansion and sclerification of olive (Olea europaea) fruits, used as an example of drupe-type fruits, from trees growing under different water regimes: full irrigated, deficit irrigated (moderate reduction of water availability) and rainfed (severe reduction of water availability). Fruits were sampled weekly until pit hardening, and fruit and endocarp areas were evaluated in histological preparations. An image analysis process was tested and adjusted to quantify sclerified area and distribution within the endocarp. Individual stone cells differentiated independently but distribution and timing indicated the overall coordination of endocarp tissue sclerification. Increase in sclerified area was initially gradual, accelerated abruptly the week prior to the end of endocarp expansion and then continued at an intermediate rate. These results suggest that the end of the expansion period is driven by sclerification and the morphogenetic signals involved act first on sclerification rather than endocarp size. Intensification of sclerification and the end of expansive growth occurred first with lowest water supply. Moderate and severe reductions in water availability proportionately decreased endocarp expansion and prolonged the sclerification, delaying the date of physically perceived hardening but not affecting the final degree of endocarp sclerification. © 2013 Scandinavian Plant Physiology Society.

  4. Community exposure and vulnerability to water quality and availability: a case study in the mining-affected Pazña Municipality, Lake Poopó Basin, Bolivian Altiplano.

    PubMed

    French, Megan; Alem, Natalie; Edwards, Stephen J; Blanco Coariti, Efraín; Cauthin, Helga; Hudson-Edwards, Karen A; Luyckx, Karen; Quintanilla, Jorge; Sánchez Miranda, Oscar

    2017-10-01

    Assessing water sources for drinking and irrigation along with community vulnerability, especially in developing and rural regions, is important for reducing risk posed by poor water quality and limited water availability and accessibility. We present a case study of rural mining-agricultural communities in the Lake Poopó Basin, one of the poorest regions on the Bolivian Altiplano. Here, relatively low rainfall, high evaporation, salinization and unregulated mining activity have contributed to environmental degradation and water issues, which is a situation facing many Altiplano communities. Social data from 72 households and chemical water quality data from 27 surface water and groundwater sites obtained between August 2013 and July 2014 were used to develop locally relevant vulnerability assessment methodologies and ratings with respect to water availability and quality, and Chemical Water Quality Hazard Ratings to assess water quality status. Levels of natural and mining-related contamination in many waters (CWQHR ≥ 6; 78% of assessed sites) mean that effective remediation would be challenging and require substantial investment. Although waters of fair to good chemical quality (CWQHR ≤ 5; 22% of assessed sites) do exist, treatment may still be required depending on use, and access issues remain problematic. There is a need to comply with water quality legislation, improve and maintain basic water supply and storage infrastructure, build and operate water and wastewater treatment plants, and adequately and safely contain and treat mine waste. This study serves as a framework that could be used elsewhere for assessing and mitigating water contamination and availability affecting vulnerable populations.

  5. Community exposure and vulnerability to water quality and availability: a case study in the mining-affected Pazña Municipality, Lake Poopó Basin, Bolivian Altiplano

    NASA Astrophysics Data System (ADS)

    French, Megan; Alem, Natalie; Edwards, Stephen J.; Blanco Coariti, Efraín; Cauthin, Helga; Hudson-Edwards, Karen A.; Luyckx, Karen; Quintanilla, Jorge; Sánchez Miranda, Oscar

    2017-10-01

    Assessing water sources for drinking and irrigation along with community vulnerability, especially in developing and rural regions, is important for reducing risk posed by poor water quality and limited water availability and accessibility. We present a case study of rural mining-agricultural communities in the Lake Poopó Basin, one of the poorest regions on the Bolivian Altiplano. Here, relatively low rainfall, high evaporation, salinization and unregulated mining activity have contributed to environmental degradation and water issues, which is a situation facing many Altiplano communities. Social data from 72 households and chemical water quality data from 27 surface water and groundwater sites obtained between August 2013 and July 2014 were used to develop locally relevant vulnerability assessment methodologies and ratings with respect to water availability and quality, and Chemical Water Quality Hazard Ratings to assess water quality status. Levels of natural and mining-related contamination in many waters (CWQHR ≥ 6; 78% of assessed sites) mean that effective remediation would be challenging and require substantial investment. Although waters of fair to good chemical quality (CWQHR ≤ 5; 22% of assessed sites) do exist, treatment may still be required depending on use, and access issues remain problematic. There is a need to comply with water quality legislation, improve and maintain basic water supply and storage infrastructure, build and operate water and wastewater treatment plants, and adequately and safely contain and treat mine waste. This study serves as a framework that could be used elsewhere for assessing and mitigating water contamination and availability affecting vulnerable populations.

  6. Deep Undercooling of Tissue Water and Winter Hardiness Limitations in Timberline Flora 1

    PubMed Central

    Becwar, Michael R.; Rajashekar, Channa; Bristow, Katherine J. Hansen; Burke, Michael J.

    1981-01-01

    Deep undercooled tissue water, which froze near −40 C, was found in winter collected stem and leaf tissue of the dominant timberline tree species of the Colorado Rocky Mountains, Engelmann spruce (Picea engelmannii (Parry) Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.), and in numerous other woody species in and below the subalpine vegetation zone. Previous work on numerous woody plants indicates that deep undercooling in xylem makes probable a −40 C winter hardiness limit in stem tissue. Visual injury determinations and electrolyte loss measurements on stem tissue revealed injury near −40 C associated with the freezing of the deep undercooled stem tissue water. These results suggest that the winter hardiness limit of this woody flora is near −40 C. The relevance of deep undercooling in relation to timberline, the upper elevational limit of the subalpine forest, is discussed. PMID:16661852

  7. Determination of water environment standards based on water quality criteria in China: Limitations and feasibilities.

    PubMed

    Wang, Tieyu; Zhou, Yunqiao; Bi, Cencen; Lu, Yonglong; He, Guizhen; Giesy, John P

    2017-07-01

    There is a need to formulate water environment standards (WESs) from the current water quality criteria (WQC) in China. To this end, we briefly summarize typical mechanisms applied in several countries with longer histories of developing WESs, and three limitations to formulating WESs in China were identified. After analyzing the feasibility factors including economic development, scientific support capability and environmental policies, we realized that China is still not ready for a complete change from its current nation-wide unified WES system to a local-standard-based system. Thus, we proposed a framework for transformation from WQC to WESs in China. The framework consists of three parts, including responsibilities, processes and policies. The responsibilities include research authorization, development of guidelines, and collection of information, at both national and local levels; the processes include four steps and an impact factor system to establish water quality standards; and the policies include seven specific proposals. Copyright © 2016. Published by Elsevier B.V.

  8. 40 CFR 437.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 437.33 Section 437.33 Protection... (BAT). Except as provided in 40 CFR 125.30 through 125.32 or § 437.30(b), any existing point source subject to this subpart must achieve limitations representing the application of BAT: Limitations for...

  9. 40 CFR 437.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 437.33 Section 437.33 Protection... (BAT). Except as provided in 40 CFR 125.30 through 125.32 or § 437.30(b), any existing point source subject to this subpart must achieve limitations representing the application of BAT: Limitations for...

  10. 40 CFR 437.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 437.33 Section 437.33 Protection... (BAT). Except as provided in 40 CFR 125.30 through 125.32 or § 437.30(b), any existing point source subject to this subpart must achieve limitations representing the application of BAT: Limitations for...

  11. Estimated water use and availability in the East Narragansett Bay study area, Rhode Island, 1995-99

    USGS Publications Warehouse

    Wild, Emily C.

    2007-01-01

    Water availability became a concern in Rhode Island during a drought in 1999, and further investigation was needed to assess the current demands on the hydrologic system from withdrawals during periods of little to no precipitation. The low ground-water levels and streamflows measured in Rhode Island prompted initiation of a series of studies on water use and availability in each major drainage area in Rhode Island for the period 1995–99. The investigation of the East Narragansett Bay area is the last of these studies. The East Narragansett Bay study area (130.9 square miles) includes small sections of the Ten Mile and Westport River Basins in Rhode Island. The area was divided into three regions (islands and contiguous land areas separated by the bay) within each of which the freshwater water use and availability were assessed. During the study period from 1995 through 1999, three major public water suppliers in the study area withdrew 7.601 million gallons per day (Mgal/d) from ground-water and surface-water reservoirs. The estimated water withdrawals by minor public water suppliers during the study period were 0.063 Mgal/d. Total self-supply domestic, industrial, commercial, and agricultural withdrawals from the study area averaged 1.891 Mgal/d. Total water use in the study area averaged 16.48 Mgal/d, of which about 8.750 Mgal/d was imported from other basins. The average return flow to freshwater within the basin was 2.591 Mgal/d, which included effluent from permitted facilities and septic systems. The average return flow to saltwater (Narragansett Bay) outside of the basin was about 45.21 Mgal/d and included discharges by permitted facilities (wastewater-treatment plants and Rhode Island Pollutant Discharge Elimination Systems). The PART program, a computerized hydrographseparation application, was used for the data collected at two selected index stream-gaging stations in the East Narragansett Bay study area to determine water availability on the basis of

  12. Addressing water scarcity through limited irrigation cropping: Field experiments and modeling

    USDA-ARS?s Scientific Manuscript database

    Population growth in urbanizing areas such as the Front Range of Colorado has led to increased pressure to transfer water from agriculture to municipalities. In many cases this has led to complete dry up of productive irrigated lands. An option to complete dry-up is the practice of limited or defi...

  13. Recharging California's Groundwater: Crop Suitability and Surface Water Availability for Agricultural Groundwater Banking

    NASA Astrophysics Data System (ADS)

    Dahlke, H. E.; Kocis, T. N.; Brown, A.

    2016-12-01

    Groundwater banking, the intentional recharge of groundwater from surface water for storage and recovery, is an important conjunctive use strategy for water management in California (CA). A largely unexplored approach to groundwater banking, agricultural groundwater banking (ag-GB), utilizes flood flows and agricultural lands (alfalfa/pasture) for recharging groundwater. Understanding soil suitability for ag-GB, crop health and flooding tolerance, leaching of soil nitrate and salts, the availability of surface water for recharge, and the economic costs and benefits of ag-GB is fundamental to assessing the feasibility of local-scale implementation of ag-GB. The study presented here considers both the availability of excess streamflow (e.g., the magnitude, frequency, timing, and duration of winter flood flow) for ag-GB and the risks and benefits associated with using alfalfa fields as spreading grounds for ag-GB. The availability of surface water for winter (Nov to Apr) ag-GB were estimated based on daily streamflow records for 93 stream gauges within the Central Valley, CA. Analysis focused on high-magnitude (>90thpercentile) flows because most lower flows are likely legally allocated in CA. Results based >50 years of data indicate that an average winter/spring (Nov. - Apr.) in the Sacramento River Basin could provide 7 million acre-feet (AF) (8.6 km3) of water for ag-GB from flows above the 90th percentile. These flows originate from few storm events (5-7 events) and occur on average for 25-30 days between November and April. Wintertime on-farm recharge experiments were conducted on a 9-yr old, 15-acre alfalfa field in the Scott Valley, CA, where 135 AF and 107 AF of water were recharged during the winters of 2015 and 2016, respectively. Biomass data collected indicates that pulsed application of 6-10 ft of water on dormant alfalfa results in minimal yield loss (0.5 ton/acre reduction), short-duration saturated conditions in the root-zone, and high recharge

  14. Effects of phenology, water availability and seed source on loblolly pine biomass partitioning and transpiration.

    PubMed

    Barnes, Andrew D

    2002-07-01

    would confer tolerance to future periods of limited soil water availability. 2002 Heron Publishing--Victoria, Canada

  15. 40 CFR 432.113 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.113 Section 432.113 Protection... by the application of the best available technology economically achievable (BAT). Except as provided... representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter Maximum daily 1 Maximum...

  16. 40 CFR 432.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.13 Section 432.13 Protection... the application of the best available technology economically achievable (BAT). Except as provided in... representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter Maximum daily 1 Maximum...

  17. 40 CFR 432.13 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.13 Section 432.13 Protection... the application of the best available technology economically achievable (BAT). Except as provided in... representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter Maximum daily 1 Maximum...

  18. 40 CFR 432.83 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.83 Section 432.83 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  19. 40 CFR 432.63 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.63 Section 432.63 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  20. 40 CFR 432.83 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... application of the best available technology economically achievable (BAT). 432.83 Section 432.83 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  1. 40 CFR 432.63 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.63 Section 432.63 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  2. 40 CFR 432.113 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.113 Section 432.113 Protection... by the application of the best available technology economically achievable (BAT). Except as provided... representing the application of BAT: Effluent Limitations [BAT] Regulatedparameter Maximum daily 1 Maximum...

  3. 40 CFR 432.63 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... application of the best available technology economically achievable (BAT). 432.63 Section 432.63 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  4. 40 CFR 432.73 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.73 Section 432.73 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  5. 40 CFR 432.73 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.73 Section 432.73 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  6. 40 CFR 432.93 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.93 Section 432.93 Protection... the application of the best available technology economically achievable (BAT). Except as provided by... following effluent limitations representing the application of BAT: (a) Facilities that generate no more...

  7. 40 CFR 432.83 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... application of the best available technology economically achievable (BAT). 432.83 Section 432.83 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... the following effluent limitations representing the application of BAT: (a) Facilities that generate...

  8. 40 CFR 432.93 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.93 Section 432.93 Protection... the application of the best available technology economically achievable (BAT). Except as provided by... following effluent limitations representing the application of BAT: (a) Facilities that generate no more...

  9. User manuals for the Delaware River Basin Water Availability Tool for Environmental Resources (DRB–WATER) and associated WATER application utilities

    USGS Publications Warehouse

    Williamson, Tanja N.; Lant, Jeremiah G.

    2015-11-18

    The Water Availability Tool for Environmental Resources (WATER) is a decision support system (DSS) for the nontidal part of the Delaware River Basin (DRB) that provides a consistent and objective method of simulating streamflow under historical, forecasted, and managed conditions. WATER integrates geospatial sampling of landscape characteristics, including topographic and soil properties, with a regionally calibrated hillslope-hydrology model, an impervious-surface model, and hydroclimatic models that have been parameterized using three hydrologic response units—forested, agricultural, and developed land cover. It is this integration that enables the regional hydrologic-modeling approach used in WATER without requiring site-specific optimization or those stationary conditions inferred when using a statistical model. The DSS provides a “historical” database, ideal for simulating streamflow for 2001–11, in addition to land-cover forecasts that focus on 2030 and 2060. The WATER Application Utilities are provided with the DSS and apply change factors for precipitation, temperature, and potential evapotranspiration to a 1981–2011 climatic record provided with the DSS. These change factors were derived from a suite of general circulation models (GCMs) and representative concentration pathway (RCP) emission scenarios. These change factors are based on 25-year monthly averages (normals) that are centere on 2030 and 2060. The WATER Application Utilities also can be used to apply a 2010 snapshot of water use for the DRB; a factorial approach enables scenario testing of increased or decreased water use for each simulation. Finally, the WATER Application Utilities can be used to reformat streamflow time series for input to statistical or reservoir management software. 

  10. Ecological optimality in water-limited natural soil-vegetation systems. I - Theory and hypothesis

    NASA Technical Reports Server (NTRS)

    Eagleson, P. S.

    1982-01-01

    The solution space of an approximate statistical-dynamic model of the average annual water balance is explored with respect to the hydrologic parameters of both soil and vegetation. Within the accuracy of this model it is shown that water-limited natural vegetation systems are in stable equilibrium with their climatic and pedologic environments when the canopy density and species act to minimize average water demand stress. Theory shows a climatic limit to this equilibrium above which it is hypothesized that ecological pressure is toward maximization of biomass productivity. It is further hypothesized that natural soil-vegetation systems will develop gradually and synergistically, through vegetation-induced changes in soil structure, toward a set of hydraulic soil properties for which the minimum stress canopy density of a given species is maximum in a given climate. Using these hypotheses, only the soil effective porosity need be known to determine the optimum soil and vegetation parameters in a given climate.

  11. Farmer perceptions on factors influencing water scarcity for goats in resource-limited communal farming environments.

    PubMed

    Mdletshe, Zwelethu Mfanafuthi; Ndlela, Sithembile Zenith; Nsahlai, Ignatius Verla; Chimonyo, Michael

    2018-05-09

    The objective of the study was to compare factors influencing water scarcity for goats in areas where there are seasonal and perennial rivers under resource-limited communal farming environments. Data were collected using a structured questionnaire (n = 285) administered randomly to smallholder goat farmers from areas with seasonal and perennial rivers. Ceremonies was ranked as the major reason for keeping goats. Water scarcity was ranked the major constraint to goat production in areas with seasonal rivers when compared to areas with perennial rivers (P < 0.05). Dams and rivers were ranked as the major water source for goat drinking in areas with seasonal and perennial river systems during cool dry and rainy seasons. Rivers were ranked as an important water source for goat drinking where there are seasonal and perennial river systems during the cool dry season. Households located close (≤ 3 km) to the nearest water source reported drinking water for goats a scarce resource. These results show that river systems, season and distance to the nearest water source from a household were factors perceived by farmers to influence water scarcity for goats in resource-limited communal farming environments. Farmers should explore water-saving strategies such as recycling wastewater from kitchens and bathrooms as an alternative water source. The government may assist farmers through sinking boreholes to supply water for both humans and livestock.

  12. Water availability in +2°C and +4°C worlds.

    PubMed

    Fung, Fai; Lopez, Ana; New, Mark

    2011-01-13

    While the parties to the UNFCCC agreed in the December 2009 Copenhagen Accord that a 2°C global warming over pre-industrial levels should be avoided, current commitments on greenhouse gas emissions reductions from these same parties will lead to a 50 : 50 chance of warming greater than 3.5°C. Here, we evaluate the differences in impacts and adaptation issues for water resources in worlds corresponding to the policy objective (+2°C) and possible reality (+4°C). We simulate the differences in impacts on surface run-off and water resource availability using a global hydrological model driven by ensembles of climate models with global temperature increases of 2°C and 4°C. We combine these with UN-based population growth scenarios to explore the relative importance of population change and climate change for water availability. We find that the projected changes in global surface run-off from the ensemble show an increase in spatial coherence and magnitude for a +4°C world compared with a +2°C one. In a +2°C world, population growth in most large river basins tends to override climate change as a driver of water stress, while in a +4°C world, climate change becomes more dominant, even compensating for population effects where climate change increases run-off. However, in some basins where climate change has positive effects, the seasonality of surface run-off becomes increasingly amplified in a +4°C climate.

  13. Water use and availability in the West Narragansett Bay area, coastal Rhode Island, 1995-99

    USGS Publications Warehouse

    Nimiroski, Mark T.; Wild, Emily C.

    2006-01-01

    During the 1999 drought in Rhode Island, belowaverage precipitation caused a drop in ground-water levels and streamflow was below long-term averages. The low water levels prompted the U. S. Geological Survey and the Rhode Island Water Resources Board to conduct a series of cooperative water-use studies. The purpose of these studies is to collect and analyze water-use and water-availability data in each drainage area in the State of Rhode Island. The West Narragansett Bay study area, which covers 118 square miles in part or all of 14 towns in coastal Rhode Island, is one of nine areas investigated as part of this effort. The study area includes the western part of Narragansett Bay and Conanicut Island, which is the town of Jamestown. The area was divided into six subbasins for the assessment of water-use data. In the calculation of hydrologic budget and water availability, the Hunt, Annaquatucket, and Pettaquamscutt River Basins were combined into one subbasin because they are hydraulically connected. Eleven major water suppliers served customers in the study area, and they supplied an average of 19.301 million gallons per day during 1995–99. The withdrawals from the only minor supplier, which was in the town of East Greenwich in the Hunt River Basin, averaged 0.002 million gallons per day. The remaining withdrawals were estimated as 1.186 million gallons per day from self-supplied domestic, commercial, industrial, and agricultural users. Return flows from self-disposed water (individual sewage-disposal systems) and permitted discharges accounted for 5.623 million gallons per day. Most publicly disposed water (13.711 million gallons per day) was collected by the Rhode Island Economic Development Corporation, and by the East Greenwich, Fields Point, Jamestown, Narragansett, and Scarborough wastewater-treatment facilities. This wastewater was disposed in Narragansett Bay outside of the study area. The PART program, a computerized hydrograph-separation application

  14. Soil water availability and rooting depth as determinants of hydraulic architecture of Patagonian woody species

    Treesearch

    Sandra J. Bucci; Fabian G. Scholz; Guillermo Goldstein; Frederick C. Meinzer; Maria E. Arce

    2009-01-01

    We studied the water economy of nine woody species differing in rooting depth in a Patagonian shrub steppe from southern Argentina to understand how soil water availability and rooting depth determine their hydraulic architecture. Soil water content and potentials, leaf water potentials (Leaf) hydraulic conductivity, wood density (Pw), rooting depth, and specific leaf...

  15. Competing effects of groundwater withdrawals and climate change on water availability in semi-arid India

    NASA Astrophysics Data System (ADS)

    Sishodia, R. P.; Shukla, S.

    2017-12-01

    India, a global leader in groundwater use (250 km3/yr), is experiencing groundwater depletion. There has been a 130-fold increase in number of irrigation wells since 1960. Anticipated future increase in groundwater demand is likely to exacerbate the water availability in the semi-arid regions of India. Depending on the direction of change, future climate change may either worsen or enhance the water availability. This study uses an integrated hydrologic modeling approach (MIKE SHE MIKE 11) to compare and combine the effects of future (2040-2069) increased groundwater withdrawals and climate change on surface and groundwater flows and availability for an agricultural watershed in semi-arid south India. Modeling results showed that increased groundwater withdrawals in the future resulted in reduced surface flows (25%) and increased frequency and duration (90 days/yr) of well drying. In contrast, projected future increase in rainfall (7-43%) under the changed climate showed increased groundwater recharge (15-67%) and surface flows (9-155%). Modeling results suggest that the positive effects of climate change may enhance the water availability in this semi-arid region of India. However, in combination with increased withdrawals, climate change was shown to increase the well drying and reduce the water availability especially during dry years. A combination of management options such as flood to drip conversion, energy subsidy reductions and water storage can support increased groundwater irrigated area in the future while mitigating the well drying. A cost-benefit analysis showed that dispersed water storage and flood to drip conversion can be highly cost-effective in this semi-arid region. The study results suggest that the government and management policies need to be focused towards an integrated management of demand and supply to create a sustainable food-water-energy nexus in the region.

  16. A rill erosion-vegetation modeling approach for the evaluation of slope reclamation success in water-limited environments

    NASA Astrophysics Data System (ADS)

    Moreno de las Heras, Mariano; Diaz Sierra, Ruben; Nicolau, Jose M.; Zavala, Miguel A.

    2013-04-01

    Slope reclamation from surface mining and road construction usually shows important constraints in water-limited environments. Soil erosion is perceived as a critical process, especially when rill formation occurs, as rills can condition the spatial distribution and availability of soil moisture for plant growth, hence affecting vegetation development. On the other hand, encouraging early vegetation establishment is essential to reduce the risk of degradation in these man-made systems. This work describes a modeling approach focused on stability analysis of water-limited reclaimed slopes, where interactive relationships between rill erosion and vegetation regulate ecosystem stability. Our framework reproduces two main groups of trends along the temporal evolution of reclaimed slopes: successful trends, characterized by widespread vegetation development and the effective control of rill erosion processes; and gullying trends, characterized by the progressive loss of vegetation and a sharp logistic increase in erosion rates. Furthermore, this analytical approach allows the determination of threshold values for both vegetation cover and rill erosion that drive the system's stability, facilitating the identification of critical situations that require specific human intervention (e.g. revegetation or, in very problematic cases, revegetation combined with rill network destruction) to ensure the long-term sustainability of the restored ecosystem. We apply our threshold analysis framework in Mediterranean-dry reclaimed slopes derived form surface coal mining (the Teruel coalfield in central-east Spain), obtaining a good field-based performance. Therefore, we believe that this model is a valuable contribution for the management of water-limited reclaimed systems, as it can play an important role in decision-making during ecosystem restoration and provides a tool for the assessment of restoration success in severely disturbed landscapes.

  17. Global pattern of trends in streamflow and water availability in a changing climate

    USGS Publications Warehouse

    Milly, P.C.D.; Dunne, K.A.; Vecchia, A.V.

    2005-01-01

    Water availability on the continents is important for human health, economic activity, ecosystem function and geophysical processes. Because the saturation vapour pressure of water in air is highly sensitive to temperature, perturbations in the global water cycle are expected to accompany climate warming. Regional patterns of warming-induced changes in surface hydroclimate are complex and less certain than those in temperature, however, with both regional increases and decreases expected in precipitation and runoff. Here we show that an ensemble of 12 climate models exhibits qualitative and statistically significant skill in simulating observed regional patterns of twentieth-century multidecadal changes in streamflow. These models project 10–40% increases in runoff in eastern equatorial Africa, the La Plata basin and high-latitude North America and Eurasia, and 10–30% decreases in runoff in southern Africa, southern Europe, the Middle East and mid-latitude western North America by the year 2050. Such changes in sustainable water availability would have considerable regional-scale consequences for economies as well as ecosystems.

  18. Linking carbon and water limitations to drought-induced mortality of Pinus flexilis seedlings

    USGS Publications Warehouse

    Reinhardt, Keith; Germino, Matthew J.; Kueppers, Lara M.; Domec, Jean-Christophe; Mitton, Jeffry

    2015-01-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below −5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  19. The Great Lakes Water Balance: Data availability and annotated bibliography of selected references

    USGS Publications Warehouse

    Neff, Brian P.; Killian, Jason R.

    2003-01-01

    Water balance calculations for the Great Lakes have been made for several decades and are a key component of Great Lakes water management. Despite the importance of the water balance, little has been done to inventory and describe the data available for use in water balance calculations. This report provides a catalog and brief description of major datasets that are used to calculate the Great Lakes water balance. Several additional datasets are identified that could be used to calculate parts of the water balance but currently are not being used. Individual offices and web pages that are useful for attaining these datasets are included. Four specific data gaps are also identified. An annotated bibliography of important publications dealing with the Great Lakes water balance is included. The findings of this investigation permit resource managers and scientists to access data more easily, assess shortcomings of current datasets, and identify which data are not currently being utilized in water balance calculations.

  20. Water availability not fruitfall modulates the dry season distribution of frugivorous terrestrial vertebrates in a lowland Amazon forest

    PubMed Central

    Paredes, Omar Stalin Landázuri; Norris, Darren; de Oliveira, Tadeu Gomes

    2017-01-01

    Terrestrial vertebrate frugivores constitute one of the major guilds in tropical forests. Previous studies show that the meso-scale distribution of this group is only weakly explained by variables such as altitude and tree basal area in lowland Amazon forests. For the first time we test whether seasonally limiting resources (water and fallen fruit) affect the dry season distribution in 25 species of terrestrial vertebrates. To examine the effects of the spatial availability of fruit and water on terrestrial vertebrates we used a standardized, regularly spaced arrangement of camera-traps within 25km2 of lowland Amazon forest. Generalized linear models (GLMs) were then used to examine the influence of four variables (altitude, distance to large rivers, distance to nearest water, and presence vs absence of fruits) on the number of photos on five functional groups (all frugivores, small, medium, large and very large frugivores) and on seven of the most abundant frugivore species (Cuniculus paca, Dasyprocta leporina, Mazama americana, Mazama nemorivaga, Myoprocta acouchy, Pecari tajacu and Psophia crepitans). A total of 279 independent photos of 25 species were obtained from 900 camera-trap days. For most species and three functional groups, the variation in the number of photos per camera was significantly but weakly explained by the GLMs (deviance explained ranging from 6.2 to 48.8%). Generally, we found that the presence of water availability was more important than the presence of fallen fruit for the groups and species studied. Medium frugivores, large-bodied frugivores, and two of the more abundant species (C. paca and P. crepitans) were recorded more frequently closer to water bodies; while none of the functional groups nor the most abundant species showed any significant relationship with the presence of fallen fruit. Two functional groups and two of the seven most common frugivore species assessed in the GLMs showed significant results with species

  1. Water availability not fruitfall modulates the dry season distribution of frugivorous terrestrial vertebrates in a lowland Amazon forest.

    PubMed

    Paredes, Omar Stalin Landázuri; Norris, Darren; Oliveira, Tadeu Gomes de; Michalski, Fernanda

    2017-01-01

    Terrestrial vertebrate frugivores constitute one of the major guilds in tropical forests. Previous studies show that the meso-scale distribution of this group is only weakly explained by variables such as altitude and tree basal area in lowland Amazon forests. For the first time we test whether seasonally limiting resources (water and fallen fruit) affect the dry season distribution in 25 species of terrestrial vertebrates. To examine the effects of the spatial availability of fruit and water on terrestrial vertebrates we used a standardized, regularly spaced arrangement of camera-traps within 25km2 of lowland Amazon forest. Generalized linear models (GLMs) were then used to examine the influence of four variables (altitude, distance to large rivers, distance to nearest water, and presence vs absence of fruits) on the number of photos on five functional groups (all frugivores, small, medium, large and very large frugivores) and on seven of the most abundant frugivore species (Cuniculus paca, Dasyprocta leporina, Mazama americana, Mazama nemorivaga, Myoprocta acouchy, Pecari tajacu and Psophia crepitans). A total of 279 independent photos of 25 species were obtained from 900 camera-trap days. For most species and three functional groups, the variation in the number of photos per camera was significantly but weakly explained by the GLMs (deviance explained ranging from 6.2 to 48.8%). Generally, we found that the presence of water availability was more important than the presence of fallen fruit for the groups and species studied. Medium frugivores, large-bodied frugivores, and two of the more abundant species (C. paca and P. crepitans) were recorded more frequently closer to water bodies; while none of the functional groups nor the most abundant species showed any significant relationship with the presence of fallen fruit. Two functional groups and two of the seven most common frugivore species assessed in the GLMs showed significant results with species

  2. Water on Mars: Volatile history and resource availability

    NASA Technical Reports Server (NTRS)

    Jakosky, Bruce M.

    1991-01-01

    The existence of water on Mars is undisputed today. Measurements of atmospheric water vapor have shown that the abundance varies with location and season in a systematic way which depends on processes of exchange with the polar caps, regolith, and atmosphere. Channels, which give the appearance of having been carved by water or of having had water involved in their formation, appear in various locations on the surface; some were formed by catastrophic outflow of water from beneath the surface, while others form valley networks which give the appearance of having formed over long periods of time primarily early in the planet's history. The north polar residual cap consists of water ice, possibly containing an amount of water equivalent to a global layer several tens of meters thick. Finally, water is observed within the regolith, as adsorbed water or as water of hydration.

  3. Detection limits and cost comparisons of human- and gull-associated conventional and quantitative PCR assays in artificial and environmental waters.

    PubMed

    Riedel, Timothy E; Zimmer-Faust, Amity G; Thulsiraj, Vanessa; Madi, Tania; Hanley, Kaitlyn T; Ebentier, Darcy L; Byappanahalli, Muruleedhara; Layton, Blythe; Raith, Meredith; Boehm, Alexandria B; Griffith, John F; Holden, Patricia A; Shanks, Orin C; Weisberg, Stephen B; Jay, Jennifer A

    2014-04-01

    Some molecular methods for tracking fecal pollution in environmental waters have both PCR and quantitative PCR (qPCR) assays available for use. To assist managers in deciding whether to implement newer qPCR techniques in routine monitoring programs, we compared detection limits (LODs) and costs of PCR and qPCR assays with identical targets that are relevant to beach water quality assessment. For human-associated assays targeting Bacteroidales HF183 genetic marker, qPCR LODs were 70 times lower and there was no effect of target matrix (artificial freshwater, environmental creek water, and environmental marine water) on PCR or qPCR LODs. The PCR startup and annual costs were the lowest, while the per reaction cost was 62% lower than the Taqman based qPCR and 180% higher than the SYBR based qPCR. For gull-associated assays, there was no significant difference between PCR and qPCR LODs, target matrix did not effect PCR or qPCR LODs, and PCR startup, annual, and per reaction costs were lower. Upgrading to qPCR involves greater startup and annual costs, but this increase may be justified in the case of the human-associated assays with lower detection limits and reduced cost per sample. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Detection limits and cost comparisons of human- and gull-associated conventional and quantitative PCR assays in artificial and environmental waters

    USGS Publications Warehouse

    Riedel, Timothy E.; Zimmer-Faust, Amity G.; Thulsiraj, Vanessa; Madi, Tania; Hanley, Kaitlyn T.; Ebentier, Darcy L.; Byappanahalli, Muruleedhara N.; Layton, Blythe; Raith, Meredith; Boehm, Alexandria B.; Griffith, John F.; Holden, Patricia A.; Shanks, Orin C.; Weisberg, Stephen B.; Jay, Jennifer A.

    2014-01-01

    Some molecular methods for tracking fecal pollution in environmental waters have both PCR and quantitative PCR (qPCR) assays available for use. To assist managers in deciding whether to implement newer qPCR techniques in routine monitoring programs, we compared detection limits (LODs) and costs of PCR and qPCR assays with identical targets that are relevant to beach water quality assessment. For human-associated assays targeting Bacteroidales HF183 genetic marker, qPCR LODs were 70 times lower and there was no effect of target matrix (artificial freshwater, environmental creek water, and environmental marine water) on PCR or qPCR LODs. The PCR startup and annual costs were the lowest, while the per reaction cost was 62% lower than the Taqman based qPCR and 180% higher than the SYBR based qPCR. For gull-associated assays, there was no significant difference between PCR and qPCR LODs, target matrix did not effect PCR or qPCR LODs, and PCR startup, annual, and per reaction costs were lower. Upgrading to qPCR involves greater startup and annual costs, but this increase may be justified in the case of the human-associated assays with lower detection limits and reduced cost per sample.

  5. 40 CFR 432.63 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.63 Section 432.63 Protection... application of the best available technology economically achievable (BAT). Except as provided in 40 CFR 125... effluent limitations representing the application of BAT: (a) Facilities that generate no more than 50...

  6. 40 CFR 432.63 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.63 Section 432.63 Protection... application of the best available technology economically achievable (BAT). Except as provided in 40 CFR 125... effluent limitations representing the application of BAT: (a) Facilities that generate no more than 50...

  7. 40 CFR 432.43 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.43 Section 432.43 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... representing the application of BAT: Limitations for ammonia (as N) and total nitrogen are the same as...

  8. 40 CFR 432.83 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.83 Section 432.83 Protection... application of the best available technology economically achievable (BAT). Except as provided by 40 CFR 125... effluent limitations representing the application of BAT: (a) Facilities that generate no more than 50...

  9. 40 CFR 432.83 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.83 Section 432.83 Protection... application of the best available technology economically achievable (BAT). Except as provided by 40 CFR 125... effluent limitations representing the application of BAT: (a) Facilities that generate no more than 50...

  10. 40 CFR 432.23 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.23 Section 432.23 Protection... the application of the best available technology economically achievable (BAT). Except as provided in... representing the application of BAT: Limitations for ammonia (as N) and total nitrogen are the same as...

  11. 40 CFR 432.43 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.43 Section 432.43 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... representing the application of BAT: Limitations for ammonia (as N) and total nitrogen are the same as...

  12. 40 CFR 432.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... application of the best available technology economically achievable (BAT). 432.33 Section 432.33 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... representing the application of BAT: the limitations for ammonia (as N) and total nitrogen are the same as...

  13. 40 CFR 432.33 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.33 Section 432.33 Protection... attainable by the application of the best available technology economically achievable (BAT). Except as... representing the application of BAT: the limitations for ammonia (as N) and total nitrogen are the same as...

  14. 40 CFR 432.23 - Effluent limitations attainable by the application of the best available technology economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... application of the best available technology economically achievable (BAT). 432.23 Section 432.23 Protection... the application of the best available technology economically achievable (BAT). Except as provided in... representing the application of BAT: Limitations for ammonia (as N) and total nitrogen are the same as...

  15. Impacts of Change in Irrigation Water Availability on Food Production in the Yellow River Basin under Climate Change

    NASA Astrophysics Data System (ADS)

    Yin, Y. Y.; Tang, Q.

    2014-12-01

    Approximately 9 percent of China's population and 17 percent of its agricultural area are settled in the Yellow River Basins. Irrigation, which plays an important role in agricultural production, occupies the largest share of human consumptive water use in the basin. Given increasing water demands, the basin faces acute water scarcity. Previous studies have suggested that decrease in irrigation water availability under climate change might have an overall adverse impact on the food production of the basin. The timing and area that would face severe water stress are yet to be identified. We used a land surface hydrological model forced with the bias-corrected climatic variables from 5 climate models under 4 Representative Concentration Pathways (RCPs) to estimate total water availability in the sub-basins of the Yellow River basin. The future socioeconomic conditions, the Shared Socioeconomic Pathways (SSPs), were used to estimate the water requirement in the nonagricultural water use sectors. The irrigation water availability was estimated from the total water availability and nonagricultural water use, and the irrigation water demands were estimated based on the current irrigation project efficiencies. The timing and area of irrigation water shortage were shown and the implication of change in irrigation water availability on food production was assessed. The results show that the sub-basins with high population density and gross domestic product (GDP) are likely to confront severe water stress and reduction in food production earlier because irrigation water was to be appropriated by the rapid increase in nonagricultural water use sectors. The study stresses the need for adaptive management of water to balance agriculture and nonagricultural demands in northern China.

  16. The limit of irrigation adaption due to the inter-crop conflict of water use under changing climate and landuse

    NASA Astrophysics Data System (ADS)

    Okada, M.; Iizumi, T.; Sakamoto, T.; Kotoku, M.; Sakurai, G.; Nishimori, M.

    2017-12-01

    Replacing rainfed cropping system by irrigated one is assumed to be an effective measure for climate change adaptation in agriculture. However, in many agricultural impact assessments, future irrigation scenarios are externally given and do not consider variations in the availability of irrigation water under changing climate and land use. Therefore, we assess the potential effects of adaption measure expanding irrigated area under climate change by using a large-scale crop-river coupled model, CROVER [Okada et al. 2015, JAMES]. The CROVER model simulates the large-scale terrestrial hydrological cycle and crop growth depending on climate, soil properties, landuse, crop cultivation management, socio-economic water demand, and reservoir operation management. The bias-corrected GCMs outputs under the RCP 8.5 scenario were used. The future expansion of irrigation area was estimated by using the extrapolation method based on the historical change in irrigated and rainfed areas. As the results, the irrigation adaptation has only a limited effect on the rice production in East Asia due to the conflict of water use for irrigation with the other crops, whose farmlands require unsustainable water extraction with the excessively expanding irrigated area. In contrast, the irrigation adaptation benefits maize production in Europe due to the little conflict of water use for irrigation. Our findings suggest the importance of simulating the river water availability and crop production in a single model for the more realistic assessment in the irrigation adaptation potential effects of crop production under changing climate and land use.

  17. Quantifying Fast and Slow Responses of Terrestrial Carbon Exchange across a Water Availability Gradient in North American Flux Sites

    NASA Astrophysics Data System (ADS)

    Biederman, J. A.; Scott, R. L.; Goulden, M.

    2014-12-01

    Climate change is predicted to increase the frequency and severity of water limitation, altering terrestrial ecosystems and their carbon exchange with the atmosphere. Here we compare site-level temporal sensitivity of annual carbon fluxes to interannual variations in water availability against cross-site spatial patterns over a network of 19 eddy covariance flux sites. This network represents one order of magnitude in mean annual productivity and includes western North American desert shrublands and grasslands, savannahs, woodlands, and forests with continuous records of 4 to 12 years. Our analysis reveals site-specific patterns not identifiable in prior syntheses that pooled sites. We interpret temporal variability as an indicator of ecosystem response to annual water availability due to fast-changing factors such as leaf stomatal response and microbial activity, while cross-site spatial patterns are used to infer ecosystem adjustment to climatic water availability through slow-changing factors such as plant community and organic carbon pools. Using variance decomposition, we directly quantify how terrestrial carbon balance depends on slow- and fast-changing components of gross ecosystem production (GEP) and total ecosystem respiration (TER). Slow factors explain the majority of variance in annual net ecosystem production (NEP) across the dataset, and their relative importance is greater at wetter, forest sites than desert ecosystems. Site-specific offsets from spatial patterns of GEP and TER explain one third of NEP variance, likely due to slow-changing factors not directly linked to water, such as disturbance. TER and GEP are correlated across sites as previously shown, but our site-level analysis reveals surprisingly consistent linear relationships between these fluxes in deserts and savannahs, indicating fast coupling of TER and GEP in more arid ecosystems. Based on the uncertainty associated with slow and fast factors, we suggest a framework for improved

  18. 40 CFR 442.43 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Effluent limitations attainable by the application of best available technology economically achievable (BAT). [Reserved] 442.43 Section 442.43... achievable (BAT). [Reserved] ...

  19. 40 CFR 442.43 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Effluent limitations attainable by the application of best available technology economically achievable (BAT). [Reserved] 442.43 Section 442.43... achievable (BAT). [Reserved] ...

  20. 40 CFR 442.43 - Effluent limitations attainable by the application of best available technology economically...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Effluent limitations attainable by the application of best available technology economically achievable (BAT). [Reserved] 442.43 Section 442.43... achievable (BAT). [Reserved] ...

  1. Stability limit of liquid water in metastable equilibrium with subsaturated vapors.

    PubMed

    Wheeler, Tobias D; Stroock, Abraham D

    2009-07-07

    A pure liquid can reach metastable equilibrium with its subsaturated vapor across an appropriate membrane. This situation is analogous to osmotic equilibrium: the reduced chemical potential of the dilute phase (the subsaturated vapor) is compensated by a difference in pressure between the phases. To equilibrate with subsaturated vapor, the liquid phase assumes a pressure that is lower than its standard vapor pressure, such that the liquid phase is metastable with respect to the vapor phase. For sufficiently subsaturated vapors, the liquid phase can even assume negative pressures. The appropriate membrane for this metastable equilibrium must provide the necessary mechanical support to sustain the difference in pressure between the two phases, limit nonhomogeneous mechanisms of cavitation, and resist the entry of the dilutant (gases) into the pure phase (liquid). In this article, we present a study of the limit of stability of liquid water--the degree of subsaturation at which the liquid cavitates--in this metastable state within microscale voids embedded in hydrogel membranes. We refer to these structures as vapor-coupled voids (VCVs). In these VCVs, we observed that liquid water cavitated when placed in equilibrium with vapors of activity aw,vapairlimiting pressure is smaller in magnitude than the limit predicted by homogeneous nucleation theory or molecular simulations (Pcav=-140 to -180 MPa). To determine the cause of the disparity between the observed and predicted stability limit, we examine experimentally the likelihood of several nonhomogeneous mechanisms of nucleation: (i) heterogeneous nucleation caused by hydrophobic patches on void walls, (ii) nucleation caused by the presence of dissolved solute, (iii) nucleation caused by the presence of pre-existing vapor nuclei, and (iv

  2. Probabilistic Water Availability Prediction in the Rio Grande Basin using Large-scale Circulation Indices as Precursor

    NASA Astrophysics Data System (ADS)

    Khedun, C. P.; Mishra, A. K.; Giardino, J. R.; Singh, V. P.

    2011-12-01

    Hydrometeorological conditions, and therefore water availability, is affected by large-scale circulation indices. In the Rio Grande, which is a transboundary basin shared between the United States and Mexico, the Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) influence local hydrological conditions. Different sub-regions of the basin exhibit varying degrees of correlation, but in general, an increase (decrease) in runoff during El Niños (La Niñas) is noted. Positive PDO enhances the effect of El Niño and dampens the negative effect of La Niña, and when it is in its neutral/transition phase, La Niña dominates climatic conditions and reduces water availability. Further, lags of up to 3 months have been found between ENSO and precipitation in the basin. We hypothesize that (1) a trivariate statistical relationship can be established between the two climate indices and water availability, and (2) the relationship can be used to predict water availability based on projected PDO and ENSO conditions. We use copula to establish the dependence between climate indices and water availability. Water availability is generated from Noah land surface model (LSM), forced with the North American Land Data Assimilation System Phase 2 (NLDAS-2). The model is run within NASA GSFC's Land Information System. LSM generated runoff gives a more realistic picture of available surface water as it is not affected by anthropogenic changes, such as the construction of dams, diversions, and other land use land cover changes, which may obscure climatic influences. Marginals from climate indices and runoff are from different distribution families, thus conventional functional forms of multivariate frequency distributions cannot be employed. Copulas offer a viable alternative as marginals from different families can be combined into a joint distribution. Uncertainties in the statistical relationship can be determined and the statistical model can be used for

  3. New steady-state models for water-limited cropping systems using saline irrigation waters: Analytical solutions and applications

    USDA-ARS?s Scientific Manuscript database

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mod...

  4. New steady-state models for water-limited cropping systems using saline irrigation waters: Analytical solutions and applications

    USDA-ARS?s Scientific Manuscript database

    Due to the diminishing availability of good quality water for irrigation, it is increasingly important that irrigation and salinity management tools be able to target submaximal crop yields and support the use of marginal quality waters. In this work, we present a steady-state irrigated systems mode...

  5. Forests in a water limited world under climate change

    NASA Astrophysics Data System (ADS)

    Mátyás, Csaba; Sun, Ge

    2014-08-01

    The debate on ecological and climatic benefits of planted forests at the sensitive dry edge of the closed forest belt (i.e. at the ‘xeric limits’) is still unresolved. Forests sequester atmospheric carbon dioxide, accumulate biomass, control water erosion and dust storms, reduce river sedimentation, and mitigate small floods. However, planting trees in areas previously dominated by grassland or cropland can dramatically alter the energy and water balances at multiple scales. The forest/grassland transition zone is especially vulnerable to projected drastic temperature and precipitation shifts and growing extremes due to its high ecohydrological sensitivity. We investigated some of the relevant aspects of the ecological and climatic role of forests and potential impacts of climate change at the dryland margins of the temperate-continental zone using case studies from China, the United States and SE Europe (Hungary). We found that, contrary to popular expectations, the effects of forest cover on regional climate might be limited and the influence of forestation on water resources might be negative. Planted forests generally reduce stream flow and lower groundwater table level because of higher water use than previous land cover types. Increased evaporation potential due to global warming and/or extreme drought events is likely to reduce areas that are appropriate for tree growth and forest establishment. Ecologically conscious forest management and forestation planning should be adjusted to the local, projected hydrologic and climatic conditions, and should also consider non-forest alternative land uses.

  6. Impacts of Potential Changes in Land Use, Climate, and Water Use on Water Availability, Coastal Carolinas Region, Southeastern United States

    NASA Astrophysics Data System (ADS)

    Gurley, L. N.; Garcia, A. M.

    2017-12-01

    Sustainable growth in coastal areas with rapidly increasing populations, such as the coastal regions of North and South Carolina, relies on an understanding of the current state of coastal natural resources coupled with the ability to assess future impacts of changing coastal communities and resources. Changes in climate, water use, population, and land use (e.g. urbanization) will place additional stress on societal and ecological systems that are already competing for water resources. The potential effects of these stressors on water availability are not fully known. To meet societal and ecological needs, water resources management and planning efforts require estimates of likely impacts of population growth, land-use, and climate. Two Soil and Water Assessment (SWAT) hydrologic models were developed to help address the challenges that water managers face in the Carolinas: the (1) Cape Fear and (2) Pee Dee drainage basins. SWAT is a basin-scale, process-based watershed model with the capability of simulating water-management scenarios. Model areas were divided into two square mile sub-basins to evaluate ecological response at headwater streams. The sub-basins were subsequently divided into smaller, discrete hydrologic response units based on land use, slope, and soil type. Monthly and annual water-use data were used for 2000 to 2014 and included estimates of municipal, industrial, agricultural, and commercial water use. Models were calibrated for 2000 to 2014 and potential future streamflows were estimated through 2060 based on a suite of scenarios that integrated land use change projections, climate projections and water-use forecasts. The approaches and new techniques developed as part of this research could be applied to other coastal areas that face similar current and future water availability demands.

  7. Review and analysis of available streamflow and water-quality data for Park County, Colorado, 1962-98

    USGS Publications Warehouse

    Kimbrough, Robert A.

    2001-01-01

    Information on streamflow and surface-water and ground-water quality in Park County, Colorado, was compiled from several Federal, State, and local agencies. The data were reviewed and analyzed to provide a perspective of recent (1962-98) water-resource conditions and to help identify current and future water-quantity and water-quality concerns. Streamflow has been monitored at more than 40 sites in the county, and data for some sites date back to the early 1900's. Existing data indicate a need for increased archival of streamflow data for future use and analysis. In 1998, streamflow was continuously monitored at about 30 sites, but data were stored in a data base for only 10 sites. Water-quality data were compiled for 125 surface-water sites, 398 wells, and 30 springs. The amount of data varied considerably among sites; however, the available information provided a general indication of where water-quality constituent concentrations met or exceeded water-quality standards. Park County is primarily drained by streams in the South Platte River Basin and to a lesser extent by streams in the Arkansas River Basin. In the South Platte River Basin in Park County, more than one-half the annual streamflow occurs in May, June, and July in response to snowmelt in the mountainous headwaters. The annual snowpack is comparatively less in the Arkansas River Basin in Park County, and mean monthly streamflow is more consistent throughout the year. In some streams, the timing and magnitude of streamflow have been altered by main-stem reservoirs or by interbasin water transfers. Most values of surface-water temperature, dissolved oxygen, and pH were within recommended limits set by the Colorado Department of Public Health and Environment. Specific conductance (an indirect measure of the dissolved-solids concentration) generally was lowest in streams of the upper South Platte River Basin and higher in the southern one-half of the county in the Arkansas River Basin and in the South

  8. Bim controls IL-15 availability and limits engagement of multiple BH3-only proteins

    PubMed Central

    Kurtulus, S; Sholl, A; Toe, J; Tripathi, P; Raynor, J; Li, K-P; Pellegrini, M; Hildeman, D A

    2015-01-01

    During the effector CD8+ T-cell response, transcriptional differentiation programs are engaged that promote effector T cells with varying memory potential. Although these differentiation programs have been used to explain which cells die as effectors and which cells survive and become memory cells, it is unclear if the lack of cell death enhances memory. Here, we investigated effector CD8+ T-cell fate in mice whose death program has been largely disabled because of the loss of Bim. Interestingly, the absence of Bim resulted in a significant enhancement of effector CD8+ T cells with more memory potential. Bim-driven control of memory T-cell development required T-cell-specific, but not dendritic cell-specific, expression of Bim. Both total and T-cell-specific loss of Bim promoted skewing toward memory precursors, by enhancing the survival of memory precursors, and limiting the availability of IL-15. Decreased IL-15 availability in Bim-deficient mice facilitated the elimination of cells with less memory potential via the additional pro-apoptotic molecules Noxa and Puma. Combined, these data show that Bim controls memory development by limiting the survival of pre-memory effector cells. Further, by preventing the consumption of IL-15, Bim limits the role of Noxa and Puma in causing the death of effector cells with less memory potential. PMID:25124553

  9. Bim controls IL-15 availability and limits engagement of multiple BH3-only proteins.

    PubMed

    Kurtulus, S; Sholl, A; Toe, J; Tripathi, P; Raynor, J; Li, K-P; Pellegrini, M; Hildeman, D A

    2015-01-01

    During the effector CD8+ T-cell response, transcriptional differentiation programs are engaged that promote effector T cells with varying memory potential. Although these differentiation programs have been used to explain which cells die as effectors and which cells survive and become memory cells, it is unclear if the lack of cell death enhances memory. Here, we investigated effector CD8+ T-cell fate in mice whose death program has been largely disabled because of the loss of Bim. Interestingly, the absence of Bim resulted in a significant enhancement of effector CD8+ T cells with more memory potential. Bim-driven control of memory T-cell development required T-cell-specific, but not dendritic cell-specific, expression of Bim. Both total and T-cell-specific loss of Bim promoted skewing toward memory precursors, by enhancing the survival of memory precursors, and limiting the availability of IL-15. Decreased IL-15 availability in Bim-deficient mice facilitated the elimination of cells with less memory potential via the additional pro-apoptotic molecules Noxa and Puma. Combined, these data show that Bim controls memory development by limiting the survival of pre-memory effector cells. Further, by preventing the consumption of IL-15, Bim limits the role of Noxa and Puma in causing the death of effector cells with less memory potential.

  10. Water availability as a driver of spatial and temporal variability in vegetation in the La Mancha plain (Spain): Implications for the land-surface energy, water and carbon budget

    NASA Astrophysics Data System (ADS)

    Los, Sietse

    2017-04-01

    Vegetation is water limited in large areas of Spain and therefore a close link exists between vegetation greenness observed from satellite and moisture availability. Here we exploit this link to infer spatial and temporal variability in moisture from MODIS NDVI data and thermal data. Discrepancies in the precipitation - vegetation relationship indicate areas with an alternative supply of water (i.e. not rainfall), this can be natural where moisture is supplied by upwelling groundwater, or can be artificial where crops are irrigated. As a result spatial and temporal variability in vegetation in the La Mancha Plain appears closely linked to topography, geology, rainfall and land use. Crop land shows large variability in year-to-year vegetation greenness; for some areas this variability is linked to variability in rainfall but in other cases this variability is linked to irrigation. The differences in irrigation treatment within one plant functional type, in this case crops, will lead to errors in land surface models when ignored. The magnitude of these effects on the energy, carbon and water balance are assessed at the scale of 250 m to 200 km. Estimating the water balance correctly is of particular important since in some areas in Spain more water is used for irrigation than is supplemented by rainfall.

  11. 40 CFR 130.7 - Total maximum daily loads (TMDL) and individual water quality-based effluent limitations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Total maximum daily loads (TMDL) and individual water quality-based effluent limitations. 130.7 Section 130.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS WATER QUALITY PLANNING AND MANAGEMENT § 130.7 Total...

  12. 40 CFR 130.7 - Total maximum daily loads (TMDL) and individual water quality-based effluent limitations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 22 2011-07-01 2011-07-01 false Total maximum daily loads (TMDL) and individual water quality-based effluent limitations. 130.7 Section 130.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS WATER QUALITY PLANNING AND MANAGEMENT § 130.7 Total...

  13. Does water chemistry limit the distribution of New Zealand mud snails in Redwood National Park?

    USGS Publications Warehouse

    Vazquez, Ryan; Ward, Darren M.; Sepulveda, Adam

    2016-01-01

    New Zealand mud snails (NZMS) are exotic mollusks present in many waterways of the western United States. In 2009, NZMS were detected in Redwood Creek in Redwood National Park, CA. Although NZMS are noted for their ability to rapidly increase in abundance and colonize new areas, after more than 5 years in Redwood Creek, their distribution remains limited to a ca. 300 m reach. Recent literature suggests that low specific conductivity and environmental calcium can limit NZMS distribution. We conducted laboratory experiments, exposing NZMS collected from Redwood Creek to both natural waters and artificial treatment solutions, to determine if low conductivity and calcium concentration limit the distribution of NZMS in Redwood National Park. For natural water exposures, we held NZMS in water from their source location (conductivity 135 μS/cm, calcium 13 mg/L) or water from four other locations in the Redwood Creek watershed encompassing a range of conductivity (77–158 μS/cm) and calcium concentration (<5–13 mg/L). For exposures in treatment solutions, we manipulated both conductivity (range 20–200 μS/cm) and calcium concentration (range <5–17.5 mg/L) in a factorial design. Response variables measured included mortality and reproductive output. Adult NZMS survived for long periods (>4 months) in the lowest conductivity waters from Redwood Creek and all but the lowest-conductivity treatment solutions, regardless of calcium concentration. However, reproductive output was very low in all natural waters and all low-calcium treatment solutions. Our results suggest that water chemistry may inhibit the spread of NZMS in Redwood National Park by reducing their reproductive output.

  14. Availability of ground water in the middle Merrimack River basin, central and southern New Hampshire

    USGS Publications Warehouse

    Cotton, J.E.

    1976-01-01

    Sufficient amounts of water to supply single family homes are available from the bedrock aquifer nearly everywhere in the middle Merrimack River basin in central and southern New Hampshire. Relatively this and narrow, unconsolidated aquifers of sand or sand and gravel commonly capable of yielding more than 200 gallons per minute to properly located and constructed wells are found only in major stream valleys. The map provides a preliminary assessment of the availability of ground water in the basin, as determined by estimating the capability of the aquifers to store and transmit water. On the map, aquifers are rated as having high, medium, or low potential to yield water. Ground water in the middle Merrimack River basin is generally of good chemical quality. Most of it is clear and colorless, contains no suspended matter and practically no bacteria, water may be affected by land-use practices. Degradation of water quality may occur in unsewered residential and village areas, near solid-waste-disposal sites, agricultural land, and major highways. (Woodard-USGS)

  15. Stoichiometry, Metabolism and Nutrient Limitation Across the Periodic Table in Natural Flowing-Water Chemostats

    NASA Astrophysics Data System (ADS)

    Cohen, M. J.; Nifong, R. L.; Kurz, M. J.; Cropper, W. P.; Martin, J. B.

    2014-12-01

    Relative supplies of macro and micronutrients (C,N,P, various metals), along with light and water, controls ecosystem metabolism, trophic energy transfer and community structure. Here we test the hypothesis, using measurements from 41 spring-fed rivers in Florida, that tissue stoichiometry indicates autotroph nutrient limitation status. Low variation in discharge, temperature and chemical composition within springs, but large variation across springs creates an ideal setting to assess the relationship between limitation and resource supply. Molar N:P ranges from 0.4 to 90, subjecting autotrophs to dramatically different nutrient supply. Over this gradient, species-specific autotroph tissue C:N:P ratios are strictly homeostatic, and with no evidence that nutrient supply affects species composition. Expanding to include 19 metals and micronutrients revealed autotrophs are more plastic in response to micronutrient variation, particularly for iron and manganese whose supply fluxes are small compared to biotic demand. Using a Droop model modified to reflect springs conditions (benthic production, light limitation, high hydraulic turnover), we show that tissue stoichiometry transitions from homeostatic to plastic with the onset of nutrient limitation, providing a potentially powerful new tool for predicting nutrient limitation and thus eutrophication in flowing waters.

  16. Drought analysis and water resource availability using standardised precipitation evapotranspiration index

    NASA Astrophysics Data System (ADS)

    Hui-Mean, Foo; Yusop, Zulkifli; Yusof, Fadhilah

    2018-03-01

    Trend analysis for potential evapotranspiration (PET) and climatic water balance (CWB) is critical in identifying the wetness or dryness episodes with respect to the water surplus or deficit. The PET is computed based on the monthly average temperature for the entire Peninsular Malaysia using Thornthwaite parameterization. The trends and slope's magnitude for the PET and CWB were then investigated using Mann-Kendall, Spearman's rho tests and Thiel-Sen estimator. The 1-, 3-, 6- and 12-month standardised precipitation evapotranspiration index (SPEI) is applied to determine the drought episodes and the average recurrence interval are calculated based on the SPEI. The results indicate that most of the stations show an upward trend in annual and monthly PET while majority of the regions show an upward trend in annual CWB except for the Pahang state. The increasing trends detected in the CWB describe water is in excess especially during the northeast monsoons while the decreasing trends imply water insufficiency. The excess water is observed mostly in January especially in the west coast, east coast and southwest regions that suggest more water is available for crop requirement. The average recurrence interval for drought episodes is almost the same for the smaller severity with various time scale of SPEI and high probability of drought occurrence is observed for some regions. The findings are useful for policymakers and practitioners to improve water resources planning and management, in particular to minimise drought effects in the future. Future research shall address the influence of topography on drought behaviour using more meteorological stations and to include east Malaysia in the analysis.

  17. A remote sensing-based dry and wet limit-reference evapotranspiration model for water use monitoring

    USDA-ARS?s Scientific Manuscript database

    With increasing growth in human population, the demand for greater food production has exceeded the capability to provide a sustainable water supply for agriculture. This is exacerbated in areas suffering from prolonged drought conditions, particularly in water limited regions. Improving the managem...

  18. Using Computer Models to Explore Alternative Scenarios for Managing Limited Irrigation Water

    USDA-ARS?s Scientific Manuscript database

    Crop water stress due to low precipitation and high temperatures are the main limiting factors for agricultural production in the Great Plains. Corn is grown under either rainfed or irrigated regimes. Irrigation can improve corn profitability in this region, but over-irrigation accelerates depletio...

  19. Sunflower response to irrigation from limited water supplies with no-till management

    USDA-ARS?s Scientific Manuscript database

    Limited irrigation necessitates maximizing economic returns by rotating crops, so we conducted a field study during 2005-2009 in southwest Kansas to determine the yield response of sunflower to irrigation and evapotranspiration (ETc) and to measure plant growth parameters and soil water use. Sunflow...

  20. Water Availability in Indus River at the Upper Indus Basin under Different Climate Change Scenarios

    NASA Astrophysics Data System (ADS)

    Khan, Firdos; Pilz, Jürgen

    2015-04-01

    The last decade of the 20th century and the first decade of the 21st century showed that climate change or global warming is happening and the latter one is considered as the warmest decade over Pakistan ever in history where temperature reached 53 0C on May 26, 2010. The changing climate has impact on various areas including agriculture, water, health, among others. There are two main forces which have central role in changing climate: one is natural variability and the other one is human evoked changes, increasing the density of green house gases. The elements in the bunch of Energy-Food-Water are interlinked with one another and among them water plays a crucial role for the existence of the other two parts. This nexus is the central environmental issue around the globe generally, and is of particular importance in the developing countries. The study evaluated the importance and the availability of water in Indus River under different emission scenarios. Four emission scenarios are included, that is, the A2, B2, RCP4.5 and RCP8.5. One way coupling of regional climate models (RCMs) and Hydrological model have been implemented in this study. The PRECIS (Providing Regional Climate for Impact Studies) and CCAM (Conformal-Cubic Atmospheric Model) climate models and UBCWM (University of British Columbia Watershed Model) hydrological model are used for this purpose. It is observed that Indus River contributes 80 % of the hydro-power generation and contributes 44 % to available water annually in Pakistan. It is further investigated whether sufficient water will be available in the Indus River under climate change scenarios. Toward this goal, Tarbela Reservoir is used as a measurement tool using the parameters of the reservoir like maximum operating storage, dead level storage, discharge capacity of tunnels and spillways. The results of this study are extremely important for the economy of Pakistan in various key areas like agriculture, energy, industries and ecosystem

  1. Nonparametric rank regression for analyzing water quality concentration data with multiple detection limits.

    PubMed

    Fu, Liya; Wang, You-Gan

    2011-02-15

    Environmental data usually include measurements, such as water quality data, which fall below detection limits, because of limitations of the instruments or of certain analytical methods used. The fact that some responses are not detected needs to be properly taken into account in statistical analysis of such data. However, it is well-known that it is challenging to analyze a data set with detection limits, and we often have to rely on the traditional parametric methods or simple imputation methods. Distributional assumptions can lead to biased inference and justification of distributions is often not possible when the data are correlated and there is a large proportion of data below detection limits. The extent of bias is usually unknown. To draw valid conclusions and hence provide useful advice for environmental management authorities, it is essential to develop and apply an appropriate statistical methodology. This paper proposes rank-based procedures for analyzing non-normally distributed data collected at different sites over a period of time in the presence of multiple detection limits. To take account of temporal correlations within each site, we propose an optimal linear combination of estimating functions and apply the induced smoothing method to reduce the computational burden. Finally, we apply the proposed method to the water quality data collected at Susquehanna River Basin in United States of America, which clearly demonstrates the advantages of the rank regression models.

  2. Sphagnum-dominated bog systems are highly effective yet variable sources of bio-available iron to marine waters.

    PubMed

    Krachler, Regina; Krachler, Rudolf F; Wallner, Gabriele; Steier, Peter; El Abiead, Yasin; Wiesinger, Hubert; Jirsa, Franz; Keppler, Bernhard K

    2016-06-15

    Iron is a micronutrient of particular interest as low levels of iron limit primary production of phytoplankton and carbon fluxes in extended regions of the world's oceans. Sphagnum-peatland runoff is extraordinarily rich in dissolved humic-bound iron. Given that several of the world's largest wetlands are Sphagnum-dominated peatlands, this ecosystem type may serve as one of the major sources of iron to the ocean. Here, we studied five near-coastal creeks in North Scotland using freshwater/seawater mixing experiments of natural creek water and synthetic seawater based on a (59)Fe radiotracer technique combined with isotopic characterization of dissolved organic carbon by Accelerator Mass Spectrometry. Three of the creeks meander through healthy Sphagnum-dominated peat bogs and the two others through modified peatlands which have been subject to artificial drainage for centuries. The results revealed that, at the time of sampling (August 16-24, 2014), the creeks that run through modified peatlands delivered 11-15μg iron per liter creek water to seawater, whereas the creeks that run through intact peatlands delivered 350-470μg iron per liter creek water to seawater. To find out whether this humic-bound iron is bio-available to marine algae, we performed algal growth tests using the unicellular flagellated marine prymnesiophyte Diacronema lutheri and the unicellular marine green alga Chlorella salina, respectively. In both cases, the riverine humic material provided a highly bio-available source of iron to the marine algae. These results add a new item to the list of ecosystem services of Sphagnum-peatlands. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Particle water and pH in the eastern Mediterranean: source variability and implications for nutrient availability

    NASA Astrophysics Data System (ADS)

    Bougiatioti, Aikaterini; Nikolaou, Panayiota; Stavroulas, Iasonas; Kouvarakis, Giorgos; Weber, Rodney; Nenes, Athanasios; Kanakidou, Maria; Mihalopoulos, Nikolaos

    2016-04-01

    contributed about 27.5 % to the total aerosol water, mostly during early morning, late evening, and nighttime hours.

    The aerosol was found to be highly acidic with calculated aerosol pH varying from 0.5 to 2.8 throughout the study period. Biomass burning aerosol presented the highest values of pH in the submicron fraction and the lowest values in total water mass concentration. The low pH values observed in the submicron mode and independently of air mass origin could increase nutrient availability and especially P solubility, which is the nutrient limiting sea water productivity of the eastern Mediterranean.

  4. Potential climate change impacts on water availability and cooling water demand in the Lusatian Lignite Mining Region, Central Europe

    NASA Astrophysics Data System (ADS)

    Pohle, Ina; Koch, Hagen; Gädeke, Anne; Grünewald, Uwe; Kaltofen, Michael; Redetzky, Michael

    2014-05-01

    In the catchments of the rivers Schwarze Elster, Spree and Lusatian Neisse, hydrologic and socioeconomic systems are coupled via a complex water management system in which water users, reservoirs and water transfers are included. Lignite mining and electricity production are major water users in the region: To allow for open pit lignite mining, ground water is depleted and released into the river system while cooling water is used in the thermal power plants. In order to assess potential climate change impacts on water availability in the catchments as well as on the water demand of the thermal power plants, a climate change impact assessment was performed using the hydrological model SWIM and the long term water management model WBalMo. The potential impacts of climate change were considered by using three regional climate change scenarios of the statistical regional climate model STAR assuming a further temperature increase of 0, 2 or 3 K by the year 2050 in the region respectively. Furthermore, scenarios assuming decreasing mining activities in terms of a decreasing groundwater depression cone, lower mining water discharges, and reduced cooling water demand of the thermal power plants are considered. In the standard version of the WBalMo model cooling water demand is considered as static with regard to climate variables. However, changes in the future cooling water demand over time according to the plans of the local mining and power plant operator are considered. In order to account for climate change impacts on the cooling water demand of the thermal power plants, a dynamical approach for calculating water demand was implemented in WBalMo. As this approach is based on air temperature and air humidity, the projected air temperature and air humidity of the climate scenarios at the locations of the power plants are included in the calculation. Due to increasing temperature and decreasing precipitation declining natural and managed discharges, and hence a lower

  5. USGS Regional Groundwater Availability Studies: Quantifying Aquifer Response

    NASA Astrophysics Data System (ADS)

    Reeves, H. W.

    2017-12-01

    The U.S. Geological Survey (USGS) identified six challenges in determining groundwater availability: 1) limited direct measurement, 2) varying response times for different systems, 3) varying spatial scales for different availability questions and aquifer systems, 4) varying tolerance to changes in water levels or outflows, 5) redistribution of stresses and potential return-flow of water pumped from the system, and 6) varying chemical quality of groundwater and the role of quality in determining suitability for different uses. USGS Regional groundwater availability studies are designed to address these challenges. USGS regional groundwater availability studies focus on quantifying the groundwater budget for principal aquifers and determining how this budget has changed in response to pumping or variations in climate. This focus requires relating limited measurements to a quantitative understanding of the temporal and spatial response of regional aquifers. For most principal aquifer studies, aquifer response is quantified using regional groundwater flow models, and USGS regional groundwater availability studies have provided test cases for the development and application of advanced modeling techniques and methods. Results from regional studies from the Lake Michigan Basin and Northern Atlantic Coastal Plain illustrate how different parts of these systems respond differently to pumping with some areas showing large drawdowns and others having much less drawdown but greater capture of discharge. The Central Valley and Mississippi Embayment studies show how extensive pumping and transfer of water have resulted in much more groundwater moving through the aquifer system under current conditions compared to pre-development. These and other results from regional studies will be explored to illustrate how regional groundwater availability and related studies address the six challenges to determining groundwater availability.

  6. Stochastic estimation of plant-available soil water under fluctuating water table depths

    NASA Astrophysics Data System (ADS)

    Or, Dani; Groeneveld, David P.

    1994-12-01

    Preservation of native valley-floor phreatophytes while pumping groundwater for export from Owens Valley, California, requires reliable predictions of plant water use. These predictions are compared with stored soil water within well field regions and serve as a basis for managing groundwater resources. Soil water measurement errors, variable recharge, unpredictable climatic conditions affecting plant water use, and modeling errors make soil water predictions uncertain and error-prone. We developed and tested a scheme based on soil water balance coupled with implementation of Kalman filtering (KF) for (1) providing physically based soil water storage predictions with prediction errors projected from the statistics of the various inputs, and (2) reducing the overall uncertainty in both estimates and predictions. The proposed KF-based scheme was tested using experimental data collected at a location on the Owens Valley floor where the water table was artificially lowered by groundwater pumping and later allowed to recover. Vegetation composition and per cent cover, climatic data, and soil water information were collected and used for developing a soil water balance. Predictions and updates of soil water storage under different types of vegetation were obtained for a period of 5 years. The main results show that: (1) the proposed predictive model provides reliable and resilient soil water estimates under a wide range of external conditions; (2) the predicted soil water storage and the error bounds provided by the model offer a realistic and rational basis for decisions such as when to curtail well field operation to ensure plant survival. The predictive model offers a practical means for accommodating simple aspects of spatial variability by considering the additional source of uncertainty as part of modeling or measurement uncertainty.

  7. Influence of landscape heterogeneity on water available to tropical forests in an Amazonian catchment and implications for modeling drought response: Water Available to Tropical Forest

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

    Fang, Yilin; Leung, L. Ruby; Duan, Zhuoran

    The Amazon basin experienced periodic droughts in the past, and climate models projected more intense and frequent droughts in the future. How tropical forests respond to drought may depend on water availability, which is modulated by landscape heterogeneity. Using the one-dimensional ACME Land Model (ALM) and the three-dimensional ParFlow variably saturated flow model, a series of numerical experiments were performed for the Asu catchment in central Amazon to elucidate processes that influence water available for plant use and provide insights for improving Earth system models. Results from ParFlow show that topography has a dominant influence on groundwater table and runoffmore » through lateral flow. Without any representations of lateral processes, ALM simulates very different seasonal variations in groundwater table and runoff compared to ParFlow even if it is able to reproduce the long-term spatial average groundwater table of ParFlow through simple parameter calibration. In the ParFlow simulations, the groundwater table is evidently deeper and the soil saturation is lower in the plateau compared to the valley. However, even in the plateau during the dry season in the drought year of 2005, plant transpiration is not water stressed in the ParFlow simulations as the soil saturation is still sufficient to maintain a soil matric potential for the stomata to be fully open. This finding is insensitive to uncertainty in atmospheric forcing and soil parameters, but the empirical wilting formulation used in the models is an important factor that should be addressed using observations and modeling of coupled plant hydraulics-soil hydrology processes in future studies.« less

  8. Winter water relations at the upper elevational limits of hemlock on Mt. Ascutney, Vermont

    Treesearch

    Chandra B. Vostral; Richard L. Boyce

    2000-01-01

    Winter water relations have been monitored in hemlock (Tsuga canadensis (L.) Carr.) at their upper elevational limits for three winters, 1997, 1998, and 1999, on Mt. Ascutney, Vermont. Hemlock and white pine trees (Pinus strobus L.) reach their elevational limit on Mt. Ascutney at 640 m (2100?), while the summit has an elevation of...

  9. Detection limit of Mycobacterium chimaera in water samples for monitoring medical device safety: insights from a pilot experimental series.

    PubMed

    Schreiber, P W; Köhler, N; Cervera, R; Hasse, B; Sax, H; Keller, P M

    2018-07-01

    A growing number of Mycobacterium chimaera infections after cardiosurgery have been reported by several countries. These potentially fatal infections were traced back to contaminated heater-cooler devices (HCDs), which use water as a heat transfer medium. Aerosolization of water contaminated with M. chimaera from HCDs enables airborne transmission to patients undergoing open chest surgery. Infection control teams test HCD water samples for mycobacterial growth to guide preventive measures. The detection limit of M. chimaera in water samples, however, has not previously been investigated. To determine the detection limit of M. chimaera in water samples using laboratory-based serial dilution tests. An M. chimaera strain representative of the international cardiosurgery-associated M. chimaera outbreak was used to generate a logarithmic dilution series. Two different water volumes, 50 and 1000mL, were inoculated, and, after identical processing (centrifugation, decantation, and decontamination), seeded on mycobacteria growth indicator tube (MGIT) and Middlebrook 7H11 solid media. MGIT consistently showed a lower detection limit than 7H11 solid media, corresponding to a detection limit of ≥1.44 × 10 4 cfu/mL for 50mL and ≥2.4cfu/mL for 1000mL water samples. Solid media failed to detect M. chimaera in 50mL water samples. Depending on water volume and culture method, major differences exist in the detection limit of M. chimaera. In terms of sensitivity, 1000mL water samples in MGIT media performed best. Our results have important implications for infection prevention and control strategies in mitigation of the M. chimaera outbreak and healthcare water safety in general. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  10. The relationship between prevalence of active trachoma, water availability and its use in a Tanzanian village.

    PubMed

    Polack, Sarah; Kuper, Hannah; Solomon, Anthony W; Massae, Patrick A; Abuelo, Carolina; Cameron, Ewen; Valdmanis, Vivian; Mahande, Michael; Foster, Allen; Mabey, David

    2006-11-01

    This study aimed to establish the relationship between the prevalence of active trachoma in children, water availability and household water use in a village in Tanzania. Nine hundred and fourteen children aged 1-9 years were examined for signs of trachoma. Data were collected on time taken to collect water, amount of water collected and other trachoma risk factors. In a sub-study, 99 randomly selected households were visited twice daily on two consecutive days to document patterns of water use. The prevalence of active trachoma in the children examined was 18.4% (95% CI 15.9-20.9). Active trachoma prevalence increased with increasing water collection time (OR 2.25; 95% CI 1.13-4.46) but was unrelated to the amount of water collected. In the sub-study, active trachoma prevalence was substantially lower in children from households where more water was used for personal hygiene (P for trend < or =0.01), independent of the total amount of water used. The allocation of water to hygiene was predicted by lower water collection time. The key element in the relationship between water availability and trachoma is the allocation of water within households. Collection time may influence both the quantity of water collected and its allocation within the household.

  11. Optimizing available water capacity using microwave satellite data for improving irrigation management

    NASA Astrophysics Data System (ADS)

    Gupta, Manika; Bolten, John; Lakshmi, Venkat

    2015-04-01

    This work addresses the improvement of available water capacity by developing a technique for estimating soil hydraulic parameters through the utilization of satellite-retrieved near surface soil moisture. The prototype involves the usage of Monte Carlo analysis to assimilate historical remote sensing soil moisture data available from the Advanced Microwave Scanning Radiometer (AMSR-E) within the hydrological model. The main hypothesis used in this study is that near-surface soil moisture data contain useful information that can describe the effective hydrological conditions of the basin such that when appropriately In the method followed in this study the hydraulic parameters are derived directly from information on the soil moisture state at the AMSR-E footprint scale and the available water capacity is derived for the root zone by coupling of AMSR-E soil moisture with the physically-based hydrological model. The available capacity water, which refers to difference between the field capacity and wilting point of the soil and represent the soil moisture content at 0.33 bar and 15 bar respectively is estimated from the soil hydraulic parameters using the van Genuchten equation. The initial ranges of soil hydraulic parameters are taken in correspondence with the values available from the literature based on Soil Survey Geographic (SSURGO) database within the particular AMSR-E footprint. Using the Monte Carlo simulation, the ranges are narrowed in the region where simulation shows a good match between predicted and near-surface soil moisture from AMSR-E. In this study, the uncertainties in accurately determining the parameters of the nonlinear soil water retention function for large-scale hydrological modeling is the focus of the development of the Bayesian framework. Thus, the model forecasting has been combined with the observational information to optimize the model state and the soil hydraulic parameters simultaneously. The optimization process is divided into

  12. Projections of Declining Surface-Water Availability for the Southwestern United States

    NASA Technical Reports Server (NTRS)

    Seager, Richard; Ting, Mingfang; Li, Cuihua; Naik, Naomi; Cook, Benjamin; Nakamura, Jennifer; Liu, Haibo

    2012-01-01

    Global warming driven by rising greenhouse-gas concentrations is expected to cause wet regions of the tropics and mid to high latitudes to get wetter and subtropical dry regions to get drier and expand polewards. Over southwest North America, models project a steady drop in precipitation minus evapotranspiration, P -- E, the net flux of water at the land surface, leading to, for example, a decline in Colorado River flow. This would cause widespread and important social and ecological consequences. Here, using new simulations from the Coupled Model Intercomparison Project Five, to be assessed in Intergovernmental Panel on Climate Change Assessment Report Five, we extend previous work by examining changes in P, E, runoff and soil moisture by season and for three different water resource regions. Focusing on the near future, 2021-2040, the new simulations project declines in surface-water availability across the southwest that translate into reduced soil moisture and runoff in California and Nevada, the Colorado River headwaters and Texas.

  13. Endogenous change: on cooperation and water availability in two ancient societies

    NASA Astrophysics Data System (ADS)

    Pande, S.; Ertsen, M.

    2014-05-01

    We propose and test the theory of endogenous change in societal institutions based on historical reconstructions of two ancient civilizations, the Indus and Hohokam, in two water-scarce basins, the Indus Basin in the Indian subcontinent and the lower Colorado Basin in the southwestern United States. In our reconstructions, institutions are approximated by the scale of "cooperation", be it in the form of the extent of trade, sophisticated irrigation networks, a central state or a loosely held state with a common cultural identity. We study changes in institutions brought about by changes in factors like rainfall, population density, and land-use-induced water resource availability, in a proximate manner. These factors either change naturally or are changed by humans; in either case we contend that the changes affect the stability of cooperative structures over time. We relate the quantitative dimensions of water access by ancient populations to the co-evolution of water access and the socioeconomic and sociopolitical organizations. In doing so, we do not claim that water manipulation was the single most significant factor in stimulating social development and complexity - this would be highly reductionist. Nonetheless, we provide a discussion with the aim to enhance our understanding of the complexity of coupled human-hydrological systems. We find that scarcity triggered more complex cooperative arrangements in both Indus and Hohokam societies.

  14. Particle water and pH in the Eastern Mediterranean: sources variability and implications for nutrients availability

    NASA Astrophysics Data System (ADS)

    Nikolaou, P.; Bougiatioti, A.; Stavroulas, I.; Kouvarakis, G.; Nenes, A.; Weber, R.; Kanakidou, M.; Mihalopoulos, N.

    2015-10-01

    during early morning, late evening and nighttime hours. The aerosol was found to be highly acidic with calculated aerosol pH varying from 0.5 to 2.8 throughout the study period. Biomass burning aerosol presented the highest values of pH in the submicron fraction and the lowest values in total water mass concentration. The low pH values observed in the submicron mode and independently of air masses origin could increase nutrient availability and especially P solubility, which is the nutrient limiting sea water productivity of the eastern Mediterranean.

  15. Estimated water use and availability in the Pawtuxet and Quinebaug River basins, Rhode Island, 1995-99

    USGS Publications Warehouse

    Wild, Emily C.; Nimiroski, Mark T.

    2007-01-01

    Water availability became a concern in Rhode Island during a drought in 1999, and an investigation was needed to assess demands on the hydrologic system from withdrawals during periods of little to no precipitation. The low water levels during the drought prompted the U.S. Geological Survey and the Rhode Island Water Resources Board to begin a series of studies on water use and availability in each drainage area in Rhode Island for 1995–99. The study area for this report, which includes the Pawtuxet River Basin in central Rhode Island (231.6 square miles) and the Quinebaug River Basin in western Rhode Island (60.97 square miles), was delineated as the surface-water drainage areas of these basins. During the study period from 1995 through 1999, two major water suppliers withdrew an average of 71.86 million gallons per day (Mgal/d) from the Pawtuxet River Basin; of this amount, about 35.98 Mgal/d of potable water were exported to other basins in Rhode Island. The estimated water withdrawals from minor water suppliers were 0.026 Mgal/d in the Pawtuxet River Basin and 0.003 Mgal/d in the Quinebaug River Basin. Total self-supply withdrawals were 2.173 Mgal/d in the Pawtuxet River Basin and 0.360 Mgal/d in the Quinebaug River Basin, which has no public water supply. Total water use averaged 18.07 Mgal/d in the Pawtuxet River Basin and 0.363 Mgal/d in the Quinebaug River Basin. Total return flow in the Pawtuxet River Basin was 30.64 Mgal/d, which included about 12.28 Mgal/d that were imported from other basins in Rhode Island. Total return flow was 0.283 Mgal/d in the Quinebaug River Basin. During times of little to no recharge in the form of precipitation, the surface- and ground-water flows are from storage primarily in the stratified sand and gravel deposits; water also flows through the till deposits, but at a slower rate. The ground water discharging to the streams during times of little to no recharge from precipitation is referred to as base flow. The PART

  16. Duripan effect on soil water availability: study case in North-Central Namibia

    NASA Astrophysics Data System (ADS)

    Prudat, Brice; Bloemertz, Lena; Kuhn, Nikolaus J.

    2016-04-01

    Soils with duripan and other hardpans are frequently disregarded for agriculture. However, in North-Central Namibia, farmers cultivate a type of sandy soil with a developing duripan at few decimetres of depth. This soil is particularly valuable for Pearl Millet cultivation during years with limited rainfall. Understanding the water dynamic and the role of the duripan in the soil moisture dynamic will improve livelihood and secure food production in North-Central Namibia, in Southern Angola and other areas in the world where similar soils appear. We recorded soil water content during five months at different depth in one of these sandy soil. The comparison of the recorded data with values calculated with models based on e.g. texture indicate that the duripan plays a very important role as water reservoir. Our results demonstrate that soils with duripans should not be disregarded for agricultural development, especially in context with irregular rainfall patterns. Understanding the role of duripans based on this study will thus help to anticipate and alleviate the effect of climate change in northern Namibia and other semi-arid regions, where similar soils occur.

  17. Asynchronous Amazon Forest Canopy Phenology Indicates Adaptation to Both Water and Light Availability

    NASA Astrophysics Data System (ADS)

    Jones, M. O.; Kimball, J. S.; Nemani, R. R.

    2015-12-01

    Amazon forests represent nearly half of all tropical vegetation biomass and, through photosynthesis and respiration, annually process more than twice the amount of estimated carbon (CO2) from fossil fuel emissions. Yet the seasonality of Amazon canopy cover, and the extent to which seasonal fluctuations in water availability and photosynthetically active radiation influence these processes, is still poorly understood. Implementing six remotely sensed data sets spanning nine years (2003-2011), with reported field and flux tower data, we show that southern equatorial Amazon forests exhibit a distinctive seasonal signal. Seasonal timing of water availability, canopy biomass growth and net leaf flush are asynchronous in regions with short dry seasons and become more synchronous across a west-to-east longitudinal moisture gradient of increasing dry season length. Forest cover is responsive to seasonal disparities in both water and solar radiation availability, temporally adjusting net leaf flush to maximize use of these generally abundant resources, while reducing drought susceptibility. An accurate characterization of this asynchronous behavior allows for improved understanding of canopy phenology across contiguous tropical forests and their sensitivity to climate variability and drought. These insights can also inform land surface models to provide a more accurate representation of seasonal forest carbon allocation strategies responsive to environmental drivers.

  18. Climate change reduces water availability for agriculture by decreasing non-evaporative irrigation losses

    NASA Astrophysics Data System (ADS)

    Malek, Keyvan; Adam, Jennifer C.; Stöckle, Claudio O.; Peters, R. Troy

    2018-06-01

    Irrigation efficiency plays an important role in agricultural productivity; it affects farm-scale water demand, and the partitioning of irrigation losses into evaporative and non-evaporative components. This partitioning determines return flow generation and thus affects water availability. Over the last two decades, hydrologic and agricultural research communities have significantly improved our understanding of the impacts of climate change on water availability and food productivity. However, the impacts of climate change on the efficiency of irrigation systems, particularly on the partitioning between evaporative and non-evaporative losses, have received little attention. In this study, we incorporated a process-based irrigation module into a coupled hydrologic/agricultural modeling framework (VIC-CropSyst). To understand how climate change may impact irrigation losses, we applied VIC-CropSyst over the Yakima River basin, an important agricultural region in Washington State, U.S. We compared the historical period of 1980-2010 to an ensemble of ten projections of climate for two future periods: 2030-2060 and 2060-2090. Results averaged over the watershed showed that a 9% increase in evaporative losses will be compensated by a reduction of non-evaporative losses. Therefore, overall changes in future efficiency are negligible (-0.4%) while the Evaporative Loss Ratio (ELR) (defined as the ratio of evaporative to non-evaporative irrigation losses) is enhanced by 10%. This higher ELR is associated with a reduction in return flows, thus negatively impacting downstream water availability. Results also indicate that the impact of climate change on irrigation losses depend on irrigation type and climate scenarios.

  19. Ground-Water Availability from the Hawi Aquifer in the Kohala Area, Hawaii

    USGS Publications Warehouse

    Underwood, Mark R.; Meyer, William; Souza, William R.

    1995-01-01

    A ground-water study consisting of test-well drilling, aquifer tests, and numerical simulation was done to investigate ground-water availability in the basal part of the Hawi aquifer between the western drainage divide of Pololu Valley and Upolu Point in Kohala, Hawaii. The test-well drilling provided information on geology, water levels, water quality, vertical extent of the freshwater, and the thickness of the freshwater-saltwater transition zone in that aquifer. A total of 12 test wells were drilled at eight locations. Aquifer tests were done at five locations to estimate the hydraulic conductivity of the aquifer. Using information on the distribution of recharge, vertical extent of freshwater, hydraulic conductivity, and geometry of the basal aquifer, a numerical model was used to simulate the movement of water into, through, and out of the basal aquifer, and the effect of additional pumping on the water levels in the aquifer. Results of the modeling indicate that ground-water withdrawal of 20 million gallons per day above the existing withdrawal of 0.6 million gallons per day from the basal aquifer is hydrologically feasible, but that spacing, depth, and pumping rates of individual wells are important. If pumping is concentrated, the likelihood of saltwater intrusion is increased. The additional withdrawal of 20 million gallons per day would result in a reduction of ground-water discharge to the ocean by an amount equal to pumpage. Although model-calculated declines in water-level outside the area of pumping are small, pumping could cause some reduction of streamflow near the mouth of Pololu Stream.

  20. Implications of Upstream Flow Availability for Watershed Surface Water Supply Across the Conterminous United States

    Treesearch

    Kai Duan; Ge Sun; Peter V. Caldwell; Steven G. McNulty; Yang Zhang

    2018-01-01

    Although it is well established that the availability of upstream flow (AUF) affects downstream water supply, its significance has not been rigorously categorized and quantified at fine resolutions. This study aims to fill this gap by providing a nationwide inventory of AUF and local water resource, and assessing their roles in securing water supply across the 2,099 8-...

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