Science.gov

Sample records for 180-day snowmelt streamflows

  1. Vadose zone effects on snowmelt generated streamflow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Processes of evaporation, transpiration and absorption of water within the rood one constitute a secondary control on the amount and timing of snowmelt-generated streamflow. Even in relatively small watersheds the timing and amount of snowmelt inputs to the root zone may be highly variable due to u...

  2. Simulated soil water storage effects on streamflow generation in a mountainous snowmelt environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil processes affect the timing and amount of streamflow generated from snowmelt and are often overlooked in estimations of snowmelt generated streamflow in the western USA. We investigated the use of a soil water balance modeling approach for incorporating the effects of soil processes, in particu...

  3. Impact of soil water storage and distribution on snowmelt generated streamflow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Snowmelt is the primary source of water generating streamflow in much of the western USA and Canada. The amount and timing of this streamflow, which affects a number of management decisions, is directly related to the amount and timing of snowmelt, soil water storage and transmission. The impact of...

  4. Generation of ensemble streamflow forecasts using an enhanced version of the snowmelt runoff model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As water demand increases in the western United States, so does the need for accurate streamflow forecasts. We describe a method for generating ensemble streamflow forecasts (1-15 days) using an enhanced version of the snowmelt runoff model (SRM). Forecasts are produced for three snowmelt-dominated ...

  5. Changes in the timing of snowmelt and streamflow in Colorado: a response to recent warming

    USGS Publications Warehouse

    Clow, David W.

    2010-01-01

    Trends in the timing of snowmelt and associated runoff in Colorado were evaluated for the 1978-2007 water years using the regional Kendall test (RKT) on daily snow-water equivalent (SWE) data from snowpack telemetry (SNOTEL) sites and daily streamflow data from headwater streams. The RKT is a robust, nonparametric test that provides an increased power of trend detection by grouping data from multiple sites within a given geographic region. The RKT analyses indicated strong, pervasive trends in snowmelt and streamflow timing, which have shifted toward earlier in the year by a median of 2-3 weeks over the 29-yr study period. In contrast, relatively few statistically significant trends were detected using simple linear regression. RKT analyses also indicated that November-May air temperatures increased by a median of 0.9 degrees C decade-1, while 1 April SWE and maximum SWE declined by a median of 4.1 and 3.6 cm decade-1, respectively. Multiple linear regression models were created, using monthly air temperatures, snowfall, latitude, and elevation as explanatory variables to identify major controlling factors on snowmelt timing. The models accounted for 45% of the variance in snowmelt onset, and 78% of the variance in the snowmelt center of mass (when half the snowpack had melted). Variations in springtime air temperature and SWE explained most of the interannual variability in snowmelt timing. Regression coefficients for air temperature were negative, indicating that warm temperatures promote early melt. Regression coefficients for SWE, latitude, and elevation were positive, indicating that abundant snowfall tends to delay snowmelt, and snowmelt tends to occur later at northern latitudes and high elevations. Results from this study indicate that even the mountains of Colorado, with their high elevations and cold snowpacks, are experiencing substantial shifts in the timing of snowmelt and snowmelt runoff toward earlier in the year.

  6. Modeling streamflow from snowmelt in the upper Rio Grande

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual snowpack in the high elevation snowsheds of the Upper Rio Grande (URG) Basin is a vital source of surface water for irrigated agriculture in New Mexico. Maximum streamflow from the annual snowpack usually occurs in early May for the southernmost snowsheds (e.g., Ojo Caliente) and at the end o...

  7. Historical perspective of statewide streamflows during the 2002 and 1977 droughts in Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard

    2005-01-01

    Since 1890, Colorado has experienced a number of widespread drought periods; the most recent statewide drought began during 1999 and includes 2002, a year characterized by precipitation, snowpack accumulation, and streamflows that were much lower than normal. Because the drought of 2002 had a substantial effect on streamflows in Colorado, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, began a study in 2004 to analyze statewide streamflows during 2002 and develop a historical perspective of those streamflows. The purpose of this report is to describe an analysis of streamflows recorded throughout Colorado during the drought of 2002, as well as other drought years such as 1977, and to provide some historical perspective of drought-diminished streamflows in Colorado. Because most streamflows in Colorado are derived from melting of mountain snowpacks during April through July, streamflows primarily were analyzed for the snowmelt (high-flow) period, but streamflows also were analyzed for the winter (low-flow) period. The snowmelt period is defined as April 1 through September 30 and the winter period is defined as October 1 through March 31. Historical daily average streamflows were analyzed on the basis of 7, 30, 90, and 180 consecutive-day periods (N-day) for 154 selected stations in Colorado. Methods used for analysis of the N-day snowmelt and winter streamflows include evaluation of trends in the historical streamflow records, computation of the rank of each annual N-day streamflow value for each station, analysis for years other than 2002 and 1977 with drought-diminished streamflows, and frequency analysis (on the basis of nonexceedance probability) of the 180-day streamflows. Ranking analyses for the N-day snowmelt streamflows indicated that streamflows during 2002 were ranked as the lowest or second lowest historical values at 114-123 stations, or about 74-80 percent of the stations; by comparison, the N-day snowmelt

  8. Streamflow Estimation from Hydrologic Model Assimilation of Remotely Sensed Snow Information in Snowmelt Dominated Basins

    NASA Astrophysics Data System (ADS)

    Dressler, K. A.; Leavesley, G.; Bales, R.; Fassnacht, S.

    2004-12-01

    The USGS Precipitation Runoff Modeling System (PRMS) hydrological model was used to evaluate the utility of experimental, gridded, 1-km2 snow covered area (SCA) and snow water equivalent (SWE) products in improving the modeling of snowmelt runoff from three headwater basins in the Southwestern United Sates. The SCA product was the fraction of each 1-km2 pixel covered by snow and was derived from NOAA Advanced Very High Resolution Radiometer imagery. The SWE product was developed by combining the SCA product with SWE estimates interpolated from National Resources Conservation Service Snow Telemetry (SNOTEL) point measurements. An eight-year period (1995-2002) was used to compare PRMS simulated streamflow generated with and without the use of the SCA and SWE products. The test basins were the Upper Rio Grande (3,397 km2) in Colorado, and the White (1,634 km2) and Black (1,441 km2) which are tributaries to the Salt River in Arizona. In model runs using the SCA and SWE products, PRMS simulated SCA and SWE values were replaced with the SCA and SWE product values each time step the products were available. The simulated energy and mass balance states of PRMS were also adjusted based on the difference between the current model state and the assimilated estimate. The largest differences between PRMS simulations of SCA and SWE, and those estimated in the SCA and SWE products, occurred in the complex, higher elevation terrain. Simulated streamflow using the assimilated products were as much as 50% less than observed streamflow over the eight year period. The largest differences between observed streamflow and that simulated using the assimilated products occurred in the topographically complex Upper Rio Grande. Differences were smaller in the White and Black basins. Use of an averaging filter to smooth the SCA and SWE products prior to assimilation improved simulated streamflow volume, especially for the Upper Rio Grande basin

  9. Contribution of Soil Moisture Information to Streamflow Prediction in the Snowmelt Season: A Continental-Scale Analysis

    NASA Technical Reports Server (NTRS)

    Reichle, Rolf; Mahanama, Sarith; Koster, Randal; Lettenmaier, Dennis

    2009-01-01

    In areas dominated by winter snowcover, the prediction of streamflow during the snowmelt season may benefit from three pieces of information: (i) the accurate prediction of weather variability (precipitation, etc.) leading up to and during the snowmelt season, (ii) estimates of the amount of snow present during the winter season, and (iii) estimates of the amount of soil moisture underlying the snowpack during the winter season. The importance of accurate meteorological predictions and wintertime snow estimates is obvious. The contribution of soil moisture to streamflow prediction is more subtle yet potentially very important. If the soil is dry below the snowpack, a significant fraction of the snowmelt may be lost to streamflow and potential reservoir storage, since it may infiltrate the soil instead for later evaporation. Such evaporative losses are presumably smaller if the soil below the snowpack is wet. In this paper, we use a state-of-the-art land surface model to quantify the contribution of wintertime snow and soil moisture information -- both together and separately -- to skill in forecasting springtime streamflow. We find that soil moisture information indeed contributes significantly to streamflow prediction skill.

  10. Onset of snowmelt and streamflow in 2004 in the Western Unites States: How shading may affect spring streamflow timing in a warmer world

    USGS Publications Warehouse

    Lundquist, J.D.; Flint, A.L.

    2006-01-01

    Historic streamflow records show that the onset of snowfed streamflow in the western United States has shifted earlier over the past 50 yr, and March 2004 was one of the earliest onsets on record. Record high temperatures occurred throughout the western United States during the second week of March, and U.S. Geological Survey (USGS) stream gauges throughout the area recorded early onsets of streamflow at this time. However, a set of nested subbasins in Yosemite National Park, California, told a more complicated story. In spite of high air temperatures, many streams draining high-elevation basins did not start flowing until later in the spring. Temperatures during early March 2004 were as high as temperatures in late March 2002, when streams at all of the monitored Yosemite basins began flowing at the same time. However, the March 2004 onset occurred before the spring equinox, when the sun was lower in the sky. Thus, shading and solar radiation differences played a much more important role in 2004, leading to differences in streamflow timing. These results suggest that as temperatures warm and spring melt shifts earlier in the season, topographic effects will play an even more important role than at present in determining snowmelt timing. ?? 2006 American Meteorological Society.

  11. Identifying streamflow sources during spring snowmelt using water chemistry and isotopic composition in semi-arid mountain streams

    NASA Astrophysics Data System (ADS)

    Jin, Li; Siegel, Donald I.; Lautz, Laura K.; Lu, Zunli

    2012-11-01

    SummaryUnderstanding streamflow generation using natural tracers in semi-arid, seasonally snow-covered mountain streams is essential for water resources management, water quality study and evaluation of impacts from climate change. This study reports temporal variations in stable isotopic ratios and concentrations of major dissolved ions of streamwater and precipitation between October, 2005 and May, 2007 in Red Canyon Creek and its tributary, Cherry Creek, draining carbonate-rich catchments on the southeastern flank of Wind River Range (Wyoming, USA). Although the isotopic ratios of oxygen and hydrogen in precipitation increased from approximately -33‰ to -13‰ and -260‰ to -110‰, respectively, during winters of 2006 and 2007, the oxygen and hydrogen isotopic compositions of streamwater at all sites remained unchanged throughout the year at -18.6 ± 0.3‰ (n = 88) and -142 ± 1.6‰ (n = 40) for δ18O and δ2H, respectively. The isotopic values for the streamwater were identical to that found in groundwater, which had the values of -18.6 ± 0.2‰ (n = 26) and -142 ± 1.1‰ (n = 26) for δ18O and δ2H, respectively. On the other hand, the temporal pattern of streamwater chemistry differed in space. In upper Red Canyon Creek, major dissolved ion concentrations in water varied little throughout the year. Nearly constant isotopic and chemical composition of streamwater at upper Red Canyon Creek indicated the dominance of the groundwater contribution throughout the year. In contrast, Cherry Creek had clear dilution of base metal and sulfate concentrations during increasing discharge at snowmelt, which is a clear indication of "new" water coming from fresh snowmelt. The contrasting behavior of stable isotopes and dissolved solutes during snowmelt at Cherry Creek suggests the isotopic tracers traditionally used in hydrograph separation failed to indicate different water sources at Cherry Creek. Combining isotopes and geochemical tracers indicates that

  12. Inferring groundwater contributions and pathways to streamflow during snowmelt over multiple years in a discontinuous permafrost subarctic environment (Yukon, Canada)

    NASA Astrophysics Data System (ADS)

    Carey, Sean K.; Boucher, Jessica L.; Duarte, Celina M.

    2013-02-01

    Research on large northern rivers suggests that as permafrost thaws, deeper groundwater flowpaths become active, resulting in greater baseflow, increased concentrations of weathering ions and reduced concentrations of dissolved organic carbon in the streamflow. In contrast, at the headwater-catchment scale, where understanding of groundwater/surface-water interactions is developed, inter-annual variability in climate and hydrology result in complex hydrological and chemical responses to change. This paper reports on a 4-year runoff investigation in an alpine discontinuous permafrost environment in Yukon, Canada, using stable isotopes, major dissolved ions and hydrometric data, to provide enhanced insight into the inter-annual-variability runoff-generation processes. Stable isotope results suggest that pre-event (old) water stored within the catchment dominates the snowmelt hydrograph, and dissolved ion results reveal that groundwater pathways occur predominantly in the near-surface during freshet. Dissolved organic carbon varies inter-annually, reflecting changing melt patterns, whereas weathering ions generated from deeper flowpaths become diluted. The total snow-water equivalent does not have a major influence on the fraction of snowmelt water reaching the stream or the runoff ratio. Results from multiple years highlight the considerable variability over short time scales, limiting our ability to detect climate-change influences on groundwater at the headwater scale.

  13. Hydrologic scales, cloud variability, remote sensing, and models: Implications for forecasting snowmelt and streamflow

    USGS Publications Warehouse

    Simpson, James J.; Dettinger, M.D.; Gehrke, F.; McIntire, T.J.; Hufford, Gary L.

    2004-01-01

    Accurate prediction of available water supply from snowmelt is needed if the myriad of human, environmental, agricultural, and industrial demands for water are to be satisfied, especially given legislatively imposed conditions on its allocation. Robust retrievals of hydrologic basin model variables (e.g., insolation or areal extent of snow cover) provide several advantages over the current operational use of either point measurements or parameterizations to help to meet this requirement. Insolation can be provided at hourly time scales (or better if needed during rapid melt events associated with flooding) and at 1-km spatial resolution. These satellite-based retrievals incorporate the effects of highly variable (both in space and time) and unpredictable cloud cover on estimates of insolation. The insolation estimates are further adjusted for the effects of basin topography using a high-resolution digital elevation model prior to model input. Simulations of two Sierra Nevada rivers in the snowmelt seasons of 1998 and 1999 indicate that even the simplest improvements in modeled insolation can improve snowmelt simulations, with 10%-20% reductions in root-mean-square errors. Direct retrieval of the areal extent of snow cover may mitigate the need to rely entirely on internal calculations of this variable, a reliance that can yield large errors that are difficult to correct until long after the season is complete and that often leads to persistent underestimates or overestimates of the volumes of the water to operational reservoirs. Agencies responsible for accurately predicting available water resources from the melt of snowpack [e.g., both federal (the National Weather Service River Forecast Centers) and state (the California Department of Water Resources)] can benefit by incorporating concepts developed herein into their operational forecasting procedures. ?? 2004 American Meteorological Society.

  14. The pulse of a montane ecosystem: coupled diurnal cycles in solar flux, snowmelt, evapotranspiration, groundwater, and streamflow at Sagehen Creek (Sierra Nevada, California)

    NASA Astrophysics Data System (ADS)

    Kirchner, James

    2016-04-01

    Forested catchments in the subalpine snow zone provide interesting opportunities to study the interplay between energy and water fluxes under seasonally variable degrees of forcing by transpiration and snowmelt. In such catchments, diurnal cycles in solar flux drive snowmelt and evapotranspiration, which in turn lead to diurnal cycles (with opposing phases) in groundwater levels. These in turn are linked to diurnal cycles in stream stage and discharge, which potentially provide a spatially integrated measure of snowmelt and evapotranspiration rates in the surrounding landscape. Here I analyze ecohydrological controls on diurnal stream and groundwater fluctuations induced by snowmelt and evapotranspiration (ET) at Sagehen Creek, in the Sierra Nevada mountains of California. There is a clear 6-hour lag between radiation forcing and the stream or groundwater response. This is not a travel-time delay, but instead a 90-degree dynamical phase lag arising from the integro-differential relationship between groundwater storage and recharge, ET, and streamflow. The time derivative of groundwater levels is strongly positively correlated with solar flux during snowmelt periods, reflecting snowmelt recharge to the riparian aquifer during daytime. Conversely, this derivative is strongly negatively correlated with solar flux during snow-free summer months, reflecting transpiration withdrawals from the riparian aquifer. As the snow cover disappears, the correlation between the solar flux and the time derivative of groundwater levels abruptly shifts from positive (snowmelt dominance) to negative (ET dominance). During this transition, the groundwater cycles briefly vanish when the opposing forcings (snowmelt and ET) are of equal magnitude, and thus cancel each other out. Stream stage fluctuations integrate these relationships over the altitude range of the catchment. Rates of rise and fall in stream stage are positively correlated with solar flux when the whole catchment is snow

  15. A model to forecast short-term snowmelt runoff using synoptic observations of streamflow, temperature, and precipitation.

    USGS Publications Warehouse

    Tangborn, W.V.

    1980-01-01

    Snowmelt runoff is forecast with a statistical model that utilizes daily values of stream discharge, gaged precipitation, and maximum and minimum observations of air temperature. Synoptic observations of these variables are made at existing low- and medium-altitude weather stations, thus eliminating the difficulties and expense of new, high-altitude installations. 4 model development steps are used to demonstrate the influence on prediction accuracy of basin storage. -from Author

  16. A Distributed Modeling System for Short-Term to Seasonal Ensemble Streamflow Forecasting in Snowmelt Dominated Basins

    SciTech Connect

    Wigmosta, Mark S.; Gill, Muhammad K.; Coleman, Andre M.; Prasad, Rajiv; Vail, Lance W.

    2007-12-01

    This paper describes a distributed modeling system for short-term to seasonal water supply forecasts with the ability to utilize remotely-sensed snow cover products and real-time streamflow measurements. Spatial variability in basin characteristics and meteorology is represented using a raster-based computational grid. Canopy interception, snow accumulation and melt, and simplified soil water movement are simulated in each computational unit. The model is run at a daily time step with surface runoff and subsurface flow aggregated at the basin scale. This approach allows the model to be updated with spatial snow cover and measured streamflow using an Ensemble Kalman-based data assimilation strategy that accounts for uncertainty in weather forecasts, model parameters, and observations used for updating. Model inflow forecasts for the Dworshak Reservoir in northern Idaho are compared to observations and to April-July volumetric forecasts issued by the Natural Resource Conservation Service (NRCS) for Water Years 2000 – 2006. October 1 volumetric forecasts are superior to those issued by the NRCS, while March 1 forecasts are comparable. The ensemble spread brackets the observed April-July volumetric inflows in all years. Short-term (one and three day) forecasts also show excellent agreement with observations.

  17. 78 FR 30390 - Applications Delayed More Than 180 Days

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration Applications Delayed More Than 180 Days AGENCY... Administration, U.S. Department of Transportation, East Building, PHH-30, 1200 New Jersey Avenue...

  18. Respiratory mechanics after 180 days space mission (EUROMIR'95)

    NASA Astrophysics Data System (ADS)

    Venturoli, Daniele; Semino, Paola; Negrini, Daniela; Miserocchi, Giuseppe

    The present study reports data on respiratory function of lung and chest wall following the 180 days long European — Russian EuroMir '95 space mission. Data reported refer to two subjects studied before the mission, on day 9 and 175 in flight and on days 1, 10, 12, 27 and 120 after return. In-flight vital capacity (VC) and expiratory reserve volume (ERV) were similar to those in supine posture, namely ~ 5% and ~ 30% less than in sitting posture. On day 1 after return, VC was reduced by ~30 % in both postures. This reflected a decrease in ERV (~0.5 L) and in IC (inspiratory capacity, ~ 1.7 L) that could be attributed to a marked weakening of the respiratory muscles. Regain of normal preflight values barely occurred 120 days after return. Post-flight pressure-volume curves of the lung, chest wall and total respiratory system are equal to preflight ones. The pressure-volume curve of the lung in supine posture is displaced to the right relative to sitting posture and shows a lower compliance. As far as the lung in-flight condition resembles that occurring in supine posture, this implies a lower compliance, a greater amount of blood in the pulmonary microvascular bed, a more homogeneous lung perfusion and therefore a greater microvascular filtration rate towards lung interstitium.

  19. 78 FR 12417 - List of Special Permit Applications Delayed 180 Days

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-22

    ... Pipeline and Hazardous Materials Safety Administration List of Special Permit Applications Delayed 180 Days AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications... of Hazardous Materials Special Permits and Approvals, Pipeline and Hazardous Materials...

  20. Subsurface processes affecting cold season streamflow generation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The amount and timing of snowmelt-generated streamflow greatly affects the management of water resources in the western USA and Canada. Subsurface processes that deliver water to streams during snowmelt are somewhat different from those that occur during rainfall. In this study we document some of ...

  1. Rapid streamflow generation from subsurface flow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Traditional streamflow forecasting from snowmelt-dominated basins has been based on snowpack dynamics. A weakness of this approach is a failure to accommodate the increasingly common mid-winter rainfall events, which are often responsible for major flooding. We recently combined a snowmelt and soil ...

  2. 76 FR 19902 - Energy Conservation Program for Consumer Products: Decision and Order Granting 180-Day Extension...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ..., DOE published a notice in the Federal Register (76 FR 17755) which announced receipt of petitions... (75 FR 64621) from the following 27 companies: (1) Adams Manufacturing Company; (2) Allied Air... 180-Day Extension of Compliance Date for Residential Furnaces and Boilers Test Procedure...

  3. 49 CFR 24.401 - Replacement housing payment for 180-day homeowner-occupants.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Replacement housing payment for 180-day homeowner-occupants. 24.401 Section 24.401 Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Replacement...

  4. 49 CFR 24.401 - Replacement housing payment for 180-day homeowner-occupants.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Replacement housing payment for 180-day homeowner-occupants. 24.401 Section 24.401 Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Replacement...

  5. 49 CFR 24.401 - Replacement housing payment for 180-day homeowner-occupants.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Has actually owned and occupied the displacement dwelling for not less than 180 days immediately prior... displacement dwelling or, in the case of condemnation, the date the full amount of the estimate of just... homeowner-occupant is paid for the displacement dwelling, or the date a comparable replacement dwelling...

  6. Snowmelt Runoff Regime Shifts Across Western North America

    NASA Astrophysics Data System (ADS)

    Fritze, H. H.; Stewart-Frey, I. T.; Pebesma, E. J.

    2009-12-01

    Snowmelt runoff serves as a climatic indicator and is of great importance for water resources across Western North America. A changing climate affects streamflow and changes its intra-annual contribution. Previous studies have found changes in snowmelt runoff towards earlier in the year through the 2000 period. The goals of this study were to a) determine whether streamflow timing trends have accelerated most recently (including the water year 2008), b) evaluate whether and where streams have experienced snowmelt runoff regime shifts, and c) develop an efficient and accessible interface to display stream hydrographs, stream details, and streamflow timing measures. Streamflow timing trends, seasonal redistribution, and correlation with climatic indices were determined by statistical analysis. Based on the ratio of years with and without snowmelt pulses this study also developed a measure of snowmelt domination and classified the streams into four categories. These categories were used to compare groups of streams with similar runoff characteristics and to quantify shifts in snowmelt domination regimes. Results show that shifts in streamflow timing have generally increased when considering the period through 2008. In addition, 15-20% of the 362 gauges included in this study have undergone a snowmelt category shift over the last decades. These category shifts are almost exclusively in the direction towards greater rain domination. The most vulnerable watersheds have changed from clearly snowmelt dominated to mostly rain dominated. Last but not least, the data and measures were interactively visualized on a virtual globe using Nasa World Wind Java and are publicly accessible from a Santa Clara University website.

  7. Hydrochemical processes during snowmelt in a subalpine watershed, Colorado, USA

    USGS Publications Warehouse

    Peters, N.E.; Leavesley, G.H.

    1995-01-01

    Snowmelt is the primary hydrologic event in the studied subalpine watershed, generating streamflow for 3 months from a 1-month snowmelt period which commenced in mid-April 1992 and mid-May 1993. The melting rate of the snowpack varied diurnally and was asymmetrical, increasing rapidly to a maximum at the onset of daily melt followed by an attenuated decrease. Streamflow varied diurnally, displaying a similar pattern to that of snowmelt, but variations were much less marked. Groundwater levels also varied diurnally, but were more attenuated than that of streamflow, and the time of daily maximum coincided with the streamflow maximum, whereas the snowmelt maximum preceded them. The major ions in meltwater were preferentially eluted from the snowpack, and meltwater was dominated by calcium, sulfate, and nitrate. The concentration decreases observed in snowmelt are partially reflected in stream water. Groundwater was dominated by calcium and generally bicarbonate. Concentrations of weathering products (silica, alkalinity, and base cations) increased down gradient, consistent with an increase in water residence time. A watershed mass balance for 1992 and 1993 indicates that (1) a major percentage of the primarily atmospherically derived N-species are retained by the watershed, (2) the watershed is the major source of base cations and silica, and (3) for the 2 year combined, atmospheric deposition balances stream water transport of sulfate and chloride.

  8. Application of a stochastic snowmelt model for probabilistic decisionmaking

    NASA Technical Reports Server (NTRS)

    Mccuen, R. H.

    1983-01-01

    A stochastic form of the snowmelt runoff model that can be used for probabilistic decision-making was developed. The use of probabilistic streamflow predictions instead of single valued deterministic predictions leads to greater accuracy in decisions. While the accuracy of the output function is important in decisionmaking, it is also important to understand the relative importance of the coefficients. Therefore, a sensitivity analysis was made for each of the coefficients.

  9. Trends and sensitivities of low streamflow extremes to discharge timing and magnitude in pacific northwest mountain streams

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historical streamflow data from the Pacific Northwest indicate that the precipitation amount has been the dominant control on the magnitude of low streamflow extremes compared to the air temperature-affected timing of snowmelt runoff. The relative sensitivities of low streamflow to precipitation and...

  10. September streamflow

    NASA Astrophysics Data System (ADS)

    Above-average streamflows dominated water conditions in the West for the 15th consecutive month, according to the September check of national water conditions by the U.S. Geological Survey (USGS). High flows were reported from Washington to southern California and eastward to central Colorado (see map, courtesy of USGS).In contrast, drier than usual conditions—with streamflows well below average—prevailed in the East and South. Low streamflows were also reported in the Ohio River valley, Kentucky, and Tennessee, and drought conditions worsened in west Texas, where no appreciable rainfall has occurred this year.

  11. Assessment of the timing of daily peak streamflow during melt season in a snow dominated watershed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown that gauge-observed daily streamflow peak times (DPT) during spring snowmelt can exhibit distinct temporal shifts through the season. These shifts have been attributed to three processes that affect the timing of snowmelt arrival: 1) melt flux translation through the snow...

  12. SWAT hydrologic model parameter uncertainty and its implications for hydroclimatic projections in snowmelt-dependent watersheds

    NASA Astrophysics Data System (ADS)

    Ficklin, Darren L.; Barnhart, Bradley L.

    2014-11-01

    The effects of climate change on water resources have been studied extensively throughout the world through the use of hydrologic models coupled with General Circulation Model (GCM) output or climate sensitivity scenarios. This paper examines the effects of hydrologic model parameterization uncertainty or equifinality, where multiple unique hydrologic model parameter sets can result in adequate calibration metrics, on hydrologic projections from downscaled GCMs for three snowmelt-dependent watersheds (upper reaches of the Clearwater, Gunnison, and Sacramento River watersheds) in the western United States. The hydrologic model used in this study is the Soil and Water Assessment Tool (SWAT) and is calibrated for discharge at the watershed outlet in each watershed. Despite achieving similar calibration metrics, a majority of hydrologic projections of average annual streamflow during the 2080s were statistically different, with differences in magnitude and direction (increase or decrease) compared to historical annual streamflows. At the average monthly time-scale, a majority of the hydrologic projections varied in peak streamflow timing, peak streamflow magnitude, summer streamflows, as well as overall increases or decreases compared to the historical monthly streamflows. Snowmelt projections from the SWAT model also widely varied, both in depth and snowmelt peak timing, for all watersheds. Since a large portion of the runoff-producing regions in the western United States is snowmelt-dependent, this has large implications for the prediction of the amount and timing of streamflow in the coming century. This paper shows that hydrologic model parameterizations that give similar adequate calibration metrics can lead to statistically significant differences in hydrologic projections under climate change. Therefore, researchers and water resource managers should account for this uncertainty by assembling ensemble projections from both multiple parameter sets and GCMs.

  13. Toward Improving Streamflow Forecasts Using SNODAS Products

    NASA Astrophysics Data System (ADS)

    Barth, C.; Boyle, D. P.; Lamorey, G. W.; Bassett, S. D.

    2007-12-01

    As part of the Water 2025 initiative, researchers at the Desert Research Institute in collaboration with the U.S. Bureau of Reclamation are developing and improving water decision support system (DSS) tools to make seasonal streamflow forecasts for management and operations of water resources in the mountainous western United States. Streamflow forecasts in these areas may have errors that are directly related to uncertainties resulting from the lack of direct high resolution snow water equivalent (SWE) measurements. The purpose of this study is to investigate the possibility of improving the accuracy of streamflow forecasts through the use of Snow Data Assimilation System (SNODAS) products, which are high-resolution daily estimates of snow cover and associated hydrologic variables such as SWE and snowmelt runoff that are available for the coterminous United States. To evaluate the benefit of incorporating the SNODAS product into streamflow forecasts, a variety of Ensemble Streamflow Predictions (ESP) are generated using the Precipitation-Runoff Modeling System (PRMS). A series of manual and automatic calibrations of PRMS to different combinations of measured (streamflow) and estimated (SNODAS SWE) hydrologic variables is performed for several watersheds at various scales of spatial resolution. This study, which is embedded in the constant effort to improve streamflow forecasts and hence water operations DSS, shows the potential of using a product such as SNODAS SWE estimates to decrease parameter uncertainty related to snow variables and enhance forecast skills early in the forecast season.

  14. Annual snowmelt and rainfall peak-flow data on selected foothills region streams, South Platte River, Arkansas River, and Colorado River basins, Colorado

    USGS Publications Warehouse

    Elliott, J.G.; Jarrett, R.D.; Ebling, J.L.

    1982-01-01

    Peak flows in the foothills region of Colorado are attributable to two meteorological sources--snowmelt and rainfall. As part of a study of the hydrology of foothills streams in Colorado, charts from streamflow gages on unregulated streams were examined to determined the source of peak-flow events. Snowmelt-runoff peaks were distinguished from rainfall-runoff peaks on the basis of daily and seasonal occurrence, hydrograph shape, and local weather conditions. Peak-flow data for snowmelt runoff and rainfall runoff are presented for 69 streamflow-gaging stations in the South Platte River, the Arkansas River, and the Colorado River basins. (USGS)

  15. March streamflow

    NASA Astrophysics Data System (ADS)

    Streamflows during March were below normal along most of the Eastern Seaboard and in the southeastern and northwestern states. However, they were above normal in a wide band extending from Michigan southwest-ward into Texas, New Mexico, and Arizona (see map), according to the U.S. Geological Survey (USGS).USGS hydrologists reported that stream-flows were about normal or above at 65% of the stream-measurement index stations in the United States. A record high flow was measured on the Colorado River in Utah, and the level of the Great Salt Lake reached its highest point in 108 years.

  16. A subchronic (180-day) oral toxicity study of ethyl tertiary-butyl ether, a bioethanol, in rats.

    PubMed

    Miyata, Katsumi; Koga, Takayuki; Aso, Sunao; Hoshuyama, Satsuki; Ajimi, Syozo; Furukawa, Kotaro

    2014-07-01

    A subchronic (180-day) toxicity study was conducted to evaluate the effects of ethyl tertiary-butyl ether (ETBE), a biomass fuel, in male and female rats. ETBE was administered at dose levels of 0, 5, 25, 100 and 400 mg/kg/body weight (b.w.)/day by gavage. No treatment-related adverse effects were observed at 5, 25 or 100 mg/kg. Centrilobular hypertrophy of hepatocytes was observed in males and females and their relative liver weights were increased, suggesting enhanced metabolic activity. From these results, we concluded that the no observed adverse effect level of ETBE was 100 mg/kg b.w./day under the conditions tested. PMID:24252074

  17. Dust-on-snow and the Timing of Peak Streamflow in the Upper Rio Grande

    NASA Astrophysics Data System (ADS)

    Steele, C. M.; Elias, E.; Moffitt, A.; Beltran, I.; Rango, A.

    2015-12-01

    Dust radiative forcing on high elevation snowpack is well-documented in the southern Rockies. Various field studies show that dust deposits decrease snow albedo and increase absorption of solar radiation, leading to earlier snowmelt and peak stream flows. These findings have implications for the use of temperature-index snow runoff models (such as the Snowmelt Runoff Model [SRM]) for predicting streamflow. In previous work, we have used SRM to simulate historical streamflow from 26 Upper Rio Grande sub-basins. Because dust radiative forcing can alter the relation between temperature and snowmelt, we wanted to find out if there is evidence of dust radiative forcing and earlier snowmelt in our study basins, particularly for those years where SRM was less successful in simulating streamflow. To accomplish this we have used openly-available data such as EPA air quality station measurements of particulate matter up to 10 micrometers (PM10); streamflow data from the USGS National Water Information System and Colorado Division of Water Resources; temperature, precipitation and snow water equivalent (SWE) from NRCS SNOTEL stations and remotely sensed data products from the MODIS sensor. Initial analyses indicate that a connection between seasonal dust concentration and streamflow timing (date of onset of warm-season snowmelt, date of streamflow center-of-volume) can be detected. This is further supported by time series analysis of MODIS-derived estimates of snow albedo and dust radiative-forcing in alpine and open subalpine snow fields.

  18. Shrub tundra snowmelt

    NASA Astrophysics Data System (ADS)

    Pomeroy, J. W.; Bewley, D. S.; Essery, R. L. H.; Hedstrom, N. R.; Link, T.; Granger, R. J.; Sicart, J. E.; Ellis, C. R.; Janowicz, J. R.

    2006-03-01

    relatively warm shrub branches, particularly on clear days. From well-exposed tall shrubs, both a large upward sensible heat flow from shrub to atmosphere and a downward flow that contributed substantially to snowmelt were detected. As a result of radiative and turbulent transfer in shrub canopies, melt rates increased with shrub exposure. However, shrub exposure was not a simple function of shrub height or presence, and the transition to shrub-exposed landscape depended on initial snow depth, shrub height, shrub species and cumulative melt, and this in turn controlled the melt energetics for a particular site. As a result of these complex interactions, observations over several years showed that snowmelt rates were generally, but not always, enhanced under shrub canopies in comparison with sparsely vegetated tundra.

  19. July streamflow

    NASA Astrophysics Data System (ADS)

    The lingering effects of a record-deep mountain snowpack continued to keep streamflows at near record high levels in much of the western United States during July. Elsewhere in the nation, a lack of rainfall and prolonged high temperatures contributed to declining streamflows, and parts of the northeast and southeast reported near record-low streamflows, according to a monthend check on water conditions by the U.S. Geological Survey (USGS). (See map, courtesy of USGS.)USGS hydrologists said that record-high streamflows were set in California, Colorado, Oregon, Utah, Washington, Wyoming, and Iowa based on reports from 172 key index stations across the country. Well above average flows during July, within the highest 25% of record, were reported at 57 of the index gaging stations. Of the remaining stations, 98 reported near-average flows and 17 reported well below average flows. Along the east coast, 12 of the 72 key index stations from Maine to Florida reported well below average flows for the month. In the extreme southwest, two stations reported their lowest July flows for the period of record.

  20. Changes toward earlier streamflow timing across western North America

    USGS Publications Warehouse

    Stewart, I.T.; Cayan, D.R.; Dettinger, M.D.

    2005-01-01

    The highly variable timing of streamflow in snowmelt-dominated basins across western North America is an important consequence, and indicator, of climate fluctuations. Changes in the timing of snowmelt-derived streamflow from 1948 to 2002 were investigated in a network of 302 western North America gauges by examining the center of mass for flow, spring pulse onset dates, and seasonal fractional flows through trend and principal component analyses. Statistical analysis of the streamflow timing measures with Pacific climate indicators identified local and key large-scale processes that govern the regionally coherent parts of the changes and their relative importance. Widespread and regionally coherent trends toward earlier onsets of springtime snowmelt and streamflow have taken place across most of western North America, affecting an area that is much larger than previously recognized. These timing changes have resulted in increasing fractions of annual flow occurring earlier in the water year by 1-4 weeks. The immediate (or proximal) forcings for the spatially coherent parts of the year-to-year fluctuations and longer-term trends of streamflow timing have been higher winter and spring temperatures. Although these temperature changes are partly controlled by the decadal-scale Pacific climate mode [Pacific decadal oscillation (PDO)], a separate and significant part of the variance is associated with a springtime warming trend that spans the PDO phases. ?? 2005 American Meteorological Society.

  1. BOREAS HYD-9 Streamflow Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Knapp, David E. (Editor); Kouwen, Nick; Soulis, Ric; Jenkinson, Wayne; Graham, Allyson; Neff, Todd; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-9 team collected several data sets containing precipitation and streamflow measurements over the BOREAS study areas. These streamflow data were collected by the HYD-09 science team to support its research into meltwater supply to the soil during the spring melt period. These data were also collected for HYD-09's research into the evolution of soil moisture, evaporation, and runoff from the end of the snowmelt period through freeze up. Data were collected in the BOREAS Southern Study Area (SSA) and Northern Study Area (NSA) from April until October in 1994, 1995, and 1996. Gauges southwest-1 and northwest-1 were operated year-round; however, data may not be available for both gauges for all three years. The data are available in tabular ASCII files. The HYD-09 streamflow data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  2. Recent tree die-off has little effect on streamflow in contrast to expected increases from historical studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent bark beetle epidemics have caused regional-scale tree mortality in many snowmelt-dominated headwater catchments of western North America. Initial expectations of increased streamflow have not been supported by observations, and the basin-scale response of annual streamflow is largely unknown....

  3. April streamflow

    NASA Astrophysics Data System (ADS)

    Heavy spring rains that fell across the nation frequently during April and early May pushed streamflows in many states to record or near-record high levels, according to a regular month end check on water resources by the U. S. Geological Survey (USGS), Department of the Interior.USGS hydrologists said new record high flows for April were measured at streams in Kansas, North Carolina, South Carolina, Nebraska, and Nevada. Near-record high flows for the month were recorded on streams in Connecticut, Pennsylvania, Iowa, and Missouri.

  4. Snowmelt Runoff Model in Japan

    NASA Technical Reports Server (NTRS)

    Ishihara, K.; Nishimura, Y.; Takeda, K.

    1985-01-01

    The preliminary Japanese snowmelt runoff model was modified so that all the input variables arc of the antecedent days and the inflow of the previous day is taken into account. A few LANDSAT images obtained in the past were effectively used to verify and modify the depletion curve induced from the snow water equivalent distribution at maximum stage and the accumulated degree days at one representative point selected in the basin. Together with the depletion curve, the relationship between the basin ide daily snowmelt amount and the air temperature at the point above are exhibited homograph form for the convenience of the model user. The runoff forecasting procedure is summarized.

  5. Extended Healing Validation of an Artificial Tendon to Connect the Quadriceps Muscle to the Tibia: 180-day Study

    PubMed Central

    Melvin, Alan J.; Litsky, Alan S.; Mayerson, Joel L.; Stringer, Keith; Juncosa-Melvin, Natalia

    2011-01-01

    Whenever a tendon or its bone insertion is disrupted or removed, existing surgical techniques provide a temporary connection or scaffolding to promote healing, but the interface of living to nonliving materials soon breaks down under the stress of these applications, if it must bear the load more than acutely. Patients are thus disabled whose prostheses, defect size, or mere anatomy limit the availability or outcomes of such treatments. Our group developed the OrthoCoupler™ device to join skeletal muscle to prosthetic or natural structures without this interface breakdown. In this study, the goat knee extensor mechanism (quadriceps tendon, patella, and patellar tendon) was removed from the right hind limb in 16 goats. The device connected the quadriceps muscle to a stainless steel bone plate on the tibia. Mechanical testing and histology specimens were collected from each operated leg and contra lateral unoperated control legs at 180 days. Maximum forces in the operated leg (vs. unoperated) were 1400± 93N (vs. 1179± 61 N), linear stiffnesses were 33± 3 N/mm (vs. 37 ± 4N/mm), and elongations at failure were 92.1 ± 5.3 mm (vs. 68.4 ± 3.8 mm; mean ± SEM). Higher maximum forces (p = 0.02) and elongations at failure (p = 0.008) of legs with the device versus unoperated controls were significant; linear stiffnesses were not (p = 0.3). We believe this technology will yield improved procedures for clinical challenges in orthopaedic oncology, revision arthroplasty, tendon transfer, and tendon injury reconstruction. PMID:22179930

  6. IMPROVED SATELLITE SNOW MAPPING, SNOWMELT RUNOFF FORECASTING, AND CLIMATE CHANGE SIMULATIONS IN THE UPPER RIO GRANDE BASIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The knowledge of snow water resources is a major concern in high elevation basins where snowmelt streamflow can make a significant contribution to the total discharge. This information is especially useful for irrigation, hydropower and water supply management. In this paper, we present a system f...

  7. Simulated impact of climate change on hydrology of multiple watersheds using traditional and recommended snowmelt runoff model methodology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For more than three decades, researchers have utilized the Snowmelt Runoff Model (SRM) to test the impacts of climate change on streamflow of snow-fed systems. In this study, the hydrological effects of climate change are modeled over three sequential years using SRM with both typical and recommende...

  8. Relationship Between Satellite-Derived Snow Cover and Snowmelt-Runoff Timing in the Wind River Range, Wyoming

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Riggs, George A.

    2010-01-01

    MODIS-derived snow cover measured on 30 April in any given year explains approximately 89 % of the variance in stream discharge for maximum monthly streamflow in that year. Observed changes in streamflow appear to be related to increasing maximum air temperatures over the last four decades causing lower spring snow-cover extent. The majority (>70%) of the water supply in the western United States comes from snowmelt, thus analysis of the declining spring snowpack (and resulting declining stream discharge) has important implications for streamflow management in the drought-prone western U.S.

  9. 49 CFR 24.502 - Replacement housing payment for 180-day mobile homeowner displaced from a mobile home, and/or...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Replacement housing payment for 180-day mobile... ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment for... payment, not to exceed $22,500, under § 24.401 if: (1) The person occupied the mobile home on...

  10. 49 CFR 24.502 - Replacement housing payment for 180-day mobile homeowner displaced from a mobile home, and/or...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Replacement housing payment for 180-day mobile... ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment for... payment, not to exceed $22,500, under § 24.401 if: (1) The person occupied the mobile home on...

  11. 49 CFR 24.502 - Replacement housing payment for 180-day mobile homeowner displaced from a mobile home, and/or...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Replacement housing payment for 180-day mobile... Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  12. 49 CFR 24.502 - Replacement housing payment for 180-day mobile homeowner displaced from a mobile home, and/or...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 false Replacement housing payment for 180-day mobile... Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  13. 49 CFR 24.502 - Replacement housing payment for 180-day mobile homeowner displaced from a mobile home, and/or...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Replacement housing payment for 180-day mobile... Transportation Office of the Secretary of Transportation UNIFORM RELOCATION ASSISTANCE AND REAL PROPERTY ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  14. Hydrological response of an Alpine catchment to rainfall and snowmelt events

    NASA Astrophysics Data System (ADS)

    Penna, D.; van Meerveld, H. J.; Zuecco, G.; Dalla Fontana, G.; Borga, M.

    2016-06-01

    Alpine catchments are important sources of fresh water but compared to lower altitude catchments our understanding of the hydrological functioning of these catchments during rainfall and snowmelt events is still limited. The objectives of this study were i) to identify the dominant runoff generation mechanisms in the 0.14-km2 Bridge Creek Catchment in the Italian Dolomites during nine rainfall-runoff events and six snowmelt-runoff events in spring, summer and autumn of 2010-2012; and ii) to assess the effect of the selection of the pre-event water sample on the isotope hydrograph separation results. The isotopic composition of the pre-event water was determined by either a stream water sample taken prior to the event or the average of 19 stream water samples taken during baseflow conditions. The hydrograph separation results for the two methods were very similar for the rainfall events but differed for the snowmelt events. Average event water contributions ranged between 4% and 19% or 2% and 20% of the total runoff during rainfall events, and between 7% and 25% or 9% and 38% during snowmelt events, depending on the method used to determine the isotopic composition of pre-event water. Event water contributions were important during large rainfall events, intense rainfall events and late in the snowmelt season, with maximum event water contributions up to 37% and 46%, depending on the method used for determining the pre-event water composition. The electrical conductivity of stream water tended to first decrease and reach a minimum before peak streamflow and then to increase above pre-event values. The results of this study suggest that during dry conditions, direct channel precipitation and overland flow from the permanently saturated part of the riparian zone dominated the runoff response, with limited contributions of riparian or hillslope groundwater. During wet or very wet conditions (large rainfall events or peak snowmelt), saturation overland flow increased

  15. Groundwater response to snowmelt in a mountainous watershed: testing of a conceptual model

    NASA Astrophysics Data System (ADS)

    Flerchinger, G. N.; Deng, Y.; Cooley, K. R.

    1993-12-01

    Snowmelt recharge to shallow (less than 25 m) groundwater systems is the primary source of streamflow in many mountainous watersheds, but characteristics of these systems are not well understood. Response time between snowmelt, piezometers and streamflow in the Upper Sheep Creek Watershed within the Reynolds Creek Experimental Watershed differs drastically from year to year depending on the extent of recharge from snowmelt. This is believed to be caused by groundwater flow becoming confined during years with normal or above normal snowmelt recharge. A two-dimensional, variably saturated, groundwater model was applied to 3 years of data to validate the computer model and to test the conceptual model of the basin. Groundwater response measured in piezometers was simulated quite accurately when a confining layer (observed in drilling logs) was included, but not when the confining layer was omitted. Simulation results give credence to the variably saturated groundwater model, support the conceptual model of the basin, and improve our understanding of the shallow groundwater system in this mountainous watershed.

  16. Physics of the spatially averaged snowmelt process

    NASA Astrophysics Data System (ADS)

    Horne, Federico E.; Kavvas, M. Levent

    1997-04-01

    It has been recognized that the snowmelt models developed in the past do not fully meet current prediction requirements. Part of the reason is that they do not account for the spatial variation in the dynamics of the spatially heterogeneous snowmelt process. Most of the current physics-based distributed snowmelt models utilize point-location-scale conservation equations which do not represent the spatially varying snowmelt dynamics over a grid area that surrounds a computational node. In this study, to account for the spatial heterogeneity of the snowmelt dynamics, areally averaged mass and energy conservation equations for the snowmelt process are developed. As a first step, energy and mass conservation equations that govern the snowmelt dynamics at a point location are averaged over the snowpack depth, resulting in depth averaged equations (DAE). In this averaging, it is assumed that the snowpack has two layers. Then, the point location DAE are averaged over the snowcover area. To develop the areally averaged equations of the snowmelt physics, we make the fundamental assumption that snowmelt process is spatially ergodic. The snow temperature and the snow density are considered as the stochastic variables. The areally averaged snowmelt equations are obtained in terms of their corresponding ensemble averages. Only the first two moments are considered. A numerical solution scheme (Runge-Kutta) is then applied to solve the resulting system of ordinary differential equations. This equation system is solved for the areal mean and areal variance of snow temperature and of snow density, for the areal mean of snowmelt, and for the areal covariance of snow temperature and snow density. The developed model is tested using Scott Valley (Siskiyou County, California) snowmelt and meteorological data. The performance of the model in simulating the observed areally averaged snowmelt is satisfactory.

  17. Mercury on the move during snowmelt in Vermont

    USGS Publications Warehouse

    Shanley, James B.; Schuster, P.F.; Reddy, M.M.; Roth, D.A.; Taylor, H.E.; Aiken, G.

    2002-01-01

    Although mercury (Hg) emissions peaked in the United States over the last 20 to 40 years and are now declining, they remain well above natural background levels in soils and sediments. Only a small fraction of the Hg deposited from the atmosphere to the terrestrial landscape runs off in streamflow. However, some of this Hg is methylated in the environment and can potentially bioaccumulate to the top of food webs, posing a hazard to people who eat fish, especially children and pregnant women. What factors determine the amount of Hg that runs off in streams? During the 2000 snowmelt at Sleepers River in Vermont, strong correlations were found between dissolved and particulate mercury and the respective dissolved and particulate organic carbon fractions, even when data were pooled from 10 streams of diverse watershed size and land cover. Episodic export of particulate Hg during the highest flows appears to be the dominant mechanism of Hg movement.

  18. Snow Cover, Snowmelt Timing and Stream Power in the Wind River Range, Wyoming

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Riggs, George A.

    2011-01-01

    Earlier onset of springtime weather, including earlier snowmelt, has been documented in the western United States over at least the last 50 years. Because the majority (is greater than 70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for the management of streamflow. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work, such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud-gap-filled (CGF) map products and 30 years of discharge and meteorological station data are studied. Streamflow data from streams in WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period as a whole. The extent of snow-cover (percent of basin covered) derived from the lowest elevation zone (2500-3000 m) of the WRR, using MODIS CGF snow-cover maps, is strongly correlated with maximum monthly discharge on 30 April, where Spearman's Rank correlation, rs,=0.89 for the decade of the 2000s. We also investigated stream power for Bull Lake Creek above Bull Lake; and found a trend (significant at the 90% confidence level) toward reduced stream power from 1970 to 2009. Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature

  19. Changes in snowmelt runoff timing in western North America under a 'business as usual' climate change scenario

    USGS Publications Warehouse

    Stewart, I.T.; Cayan, D.R.; Dettinger, M.D.

    2004-01-01

    Spring snowmelt is the most important contribution of many rivers in western North America. If climate changes, this contribution may change. A shift in the timing of springtime snowmelt towards earlier in the year already is observed during 1948-2000 in many western rivers. Streamflow timing changes for the 1995-2099 period are projected using regression relations between observed streamflow-timing responses in each river, measured by the temporal centroid of streamflow (CT) each year, and local temperature (TI) and precipitation (PI) indices. Under 21st century warming trends predicted by the Parallel Climate Model (PCM) under business-as-usual greenhouse-gas emissions, streamflow timing trends across much of western North America suggest even earlier springtime snowmelt than observed to date. Projected CT changes are consistent with observed rates and directions of change during the past five decades, and are strongest in the Pacific Northwest, Sierra Nevada, and Rocky Mountains, where many rivers eventually run 30-40 days earlier. The modest PI changes projected by PCM yield minimal CT changes. The responses of CT to the simultaneous effects of projected TI and PI trends are dominated by the TI changes. Regression-based CT projections agree with those from physically-based simulations of rivers in the Pacific Northwest and Sierra Nevada.

  20. Integration of Snow Data from Remote Sensing into Operational Streamflow Forecasting in the Western United States

    NASA Astrophysics Data System (ADS)

    Bender, S.; Painter, T. H.; Miller, W. P.; Andreadis, K.

    2014-12-01

    Managers of water resources depend on snowmelt-driven runoff for multiple purposes including water supply, irrigation, attainment of environmental goals, and power generation. Emergency managers track flood potential, particularly in years with above-normal snow conditions. The Colorado Basin River Forecast Center (CBRFC) of the National Weather Service issues operational streamflow forecasts in the western United States. Runoff during the critical April through July period is predominantly driven by snowmelt; therefore, the CBRFC and users of its forecasts consider snow observations to be highly valuable. In CBRFC's area of responsibility, the density of stations within gauge-based observation networks is not ideal. Snowpack estimates from satellite-borne instruments may aid in filling data gaps where information from point networks is unavailable. CBRFC has partnered with the Jet Propulsion Laboratory (JPL) under funding from NASA to incorporate remotely-sensed snow data from NASA's MODIS instrument into CBRFC forecasts. The partnership will enter its third year in 2015 and demonstrates an invaluable collaboration between operational and research scientists. Research indicates that streamflow prediction errors could be reduced through use of remotely-sensed snow data. In the first two years of collaboration, CBRFC and JPL increased forecaster awareness of snow conditions via the MODIS datasets, which subsequently increased forecaster confidence in manual modifications to snowpack simulations. Indication of the presence or lack of snow by MODIS assisted CBRFC forecasters in determining the cause of divergence between modeled and gauged streamflow. Indication of albedo conditions at the snow surface provided supporting information about the potential for accelerated snowmelt rates. CBRFC and JPL also continued retrospective analysis of relationships between the remotely-sensed snow data and streamflow patterns. Utilization of remotely-sensed snow data is an

  1. Streamflow, Infiltration, and Recharge in Arroyo Hondo, New Mexico

    USGS Publications Warehouse

    Moore, Stephanie J.

    2007-01-01

    Infiltration events in channels that flow only sporadically produce focused recharge to the Tesuque aquifer in the Espa?ola Basin. The current study examined the quantity and timing of streamflow and associated infiltration in Arroyo Hondo, an unregulated mountain-front stream that enters the basin from the western slope of the Sangre de Cristo Mountains. Traditional methods of stream gaging were combined with environmental-tracer based methods to provide the estimates. The study was conducted during a three-year period, October 1999?October 2002. The period was characterized by generally low precipitation and runoff. Summer monsoonal rains produced four brief periods of streamflow in water year 2000, only three of which extended beyond the mountain front, and negligible runoff in subsequent years. The largest peak flow during summer monsoon events was 0.59 cubic meters per second. Snowmelt was the main contributor to annual streamflow. Snowmelt produced more cumulative flow downstream from the mountain front during the study period than summer monsoonal rains. The presence or absence of streamflow downstream of the mountain front was determined by interpretation of streambed thermographs. Infiltration rates were estimated by numerical modeling of transient vertical streambed temperature profiles. Snowmelt extended throughout the instrumented reach during the spring of 2001. Flow was recorded at a station two kilometers downstream from the mountain front for six consecutive days in March. Inverse modeling of this event indicated an average infiltration rate of 1.4 meters per day at this location. For the entire study reach, the estimated total annual volume of infiltration ranged from 17,100 to 246,000 m3 during water years 2000 and 2001. During water year 2002, due to severe drought, streamflow and streambed infiltration in the study reach were both zero.

  2. Relationships between stream nitrate concentration and spatially distributed snowmelt in high-elevation catchments of the western U.S.

    NASA Astrophysics Data System (ADS)

    Perrot, Danielle; Molotch, Noah P.; Williams, Mark W.; Jepsen, Steven M.; Sickman, James O.

    2014-11-01

    This study compares stream nitrate (NO3-) concentrations to spatially distributed snowmelt in two alpine catchments, the Green Lakes Valley, Colorado (GLV4) and Tokopah Basin, California (TOK). A snow water equivalent reconstruction model and Landsat 5 and 7 snow cover data were used to estimate daily snowmelt at 30 m spatial resolution in order to derive indices of new snowmelt areas (NSAs). Estimates of NSA were then used to explain the NO3- flushing behavior for each basin over a 12 year period (1996-2007). To identify the optimal method for defining NSAs and elucidate mechanisms underlying catchment NO3- flushing, we conducted a series of regression analyses using multiple thresholds of snowmelt based on temporal and volumetric metrics. NSA indices defined by volume of snowmelt (e.g., snowmelt ≤ 30 cm) rather than snowmelt duration (e.g., snowmelt ≤ 9 days) were the best predictors of stream NO3- concentrations. The NSA indices were better correlated with stream NO3- concentration in TOK (average R2= 0.68) versus GLV4 (average R2= 0.44). Positive relationships between NSA and stream NO3- concentration were observed in TOK with peak stream NO3- concentration occurring on the rising limb of snowmelt. Positive and negative relationships between NSA and stream NO3- concentration were found in GLV4 with peak stream NO3- concentration occurring as NSA expands. Consistent with previous works, the contrasting NO3- flushing behavior suggests that streamflow in TOK was primarily influenced by overland flow and shallow subsurface flow, whereas GLV4 appeared to be more strongly influenced by deeper subsurface flow paths.

  3. Peak flow transitions from snowmelt to rainfall dominance along the Colorado Front Range: Spatial patterns and temporal trends

    NASA Astrophysics Data System (ADS)

    Kampf, S. K.; Lefsky, M. A.

    2015-12-01

    For a given quantity of precipitation, its form (snow or rain) will affect the magnitude and timing of streamflow, with consequences for both water resource and flood management. Using 20 streamflow gaging stations along a gradient of snow persistence and elevation, we identify annual peak flow sources (snowmelt, rainfall, mixed) from a gridded snow accumulation and melt model. We then relate these peak flow sources to annual average January-June snow persistence (SP), evaluate whether peak flow sources have changed over time, and examine how peak flow magnitude and timing differ with flow source. Results show that watersheds with SP<0.3 (low snow, mean elevation <2000 m) have experienced only rainfall-runoff annual peak flows in the period of record, and watersheds with SP>0.7 (persistent snow, mean elevation >3100 m) have mostly snowmelt-runoff peak flows, with mixed sources between these thresholds. At all elevations, rainfall may produce the annual peak flow, but the likelihood of rainfall-runoff peaks declines with increasing SP. Regional Kendall trend tests show that the contributions of snowmelt to peak flows and total annual inputs have declined in the mixed zone but not in the snowmelt-dominated zone, where SP is still high enough for peak flows to remain snowmelt-dominated. While rainfall runoff has produced some of the highest unit area peak flows in the region, on average snowmelt runoff produces higher unit discharge and more attenuated hydrographs than rainfall runoff. This example illustrates how peak flow sources are most sensitive to loss of snow in elevations where snow transitions from persistent to intermittent, whereas high elevations still have long enough snow persistence that they have remained snowmelt-dominated.

  4. Exposure to Pb, Cd, and As mixtures potentiates the production of oxidative stress precursors: 30-day, 90-day, and 180-day drinking water studies in rats

    SciTech Connect

    Whittaker, Margaret H.; Wang, Gensheng; Chen Xueqing; Lipsky, Michael; Smith, Donald; Gwiazda, Roberto; Fowler, Bruce A.

    2011-07-15

    Exposure to chemical mixtures is a common and important determinant of toxicity and is of particular concern due to their appearance in sources of drinking water. Despite this, few in vivo mixture studies have been conducted to date to understand the health impact of chemical mixtures compared to single chemicals. Interactive effects of lead (Pb), cadmium (Cd) and arsenic (As) were evaluated in 30-, 90-, and 180-day factorial design drinking water studies in rats designed to test the hypothesis that ingestion of such mixtures at individual component Lowest-Observed-Effect-Levels (LOELs) results in increased levels of the pro-oxidant delta aminolevulinic acid (ALA), iron, and copper. LOEL levels of Pb, Cd, and As mixtures resulted in the increased presence of mediators of oxidative stress such as ALA, copper, and iron. ALA increases were followed by statistically significant increases in kidney copper in the 90- and 180-day studies. Statistical evidence of interaction was identified for six biologically relevant variables: blood delta aminolevulinic acid dehydratase (ALAD), kidney ALAD, urinary ALA, urinary iron, kidney iron, and kidney copper. The current investigations underscore the importance of considering interactive effects that common toxic agents such as Pb, Cd, and As may have upon one another at low-dose levels. The interactions between known toxic trace elements at biologically relevant concentrations shown here demonstrate a clear need to rigorously review methods by which national/international agencies assess health risks of chemicals, since exposures may commonly occur as complex mixtures.

  5. Sensitivity of soil water availability to changing snowmelt timing in the western U.S.

    NASA Astrophysics Data System (ADS)

    Harpold, Adrian A.; Molotch, Noah P.

    2015-10-01

    The ecohydrological effects of changing snowmelt are strongly mediated by soil moisture. We utilize 259 Snow Telemetry stations across the western U.S. to address two questions: (1) how do relationships between peak soil moisture (PSM) timing and the day of snow disappearance (DSD) vary across ecoregions and (2) what is the regional sensitivity of PSM timing to earlier DSD associated with warming and drying scenarios? All western U.S. ecoregions showed significant relationships between the timing of PSM and DSD. Changes in the timing of PSM based on warming predicted for the middle and end of the 21st century ranged from 1 to 9 days and from 6 to 17 days among ecoregions, respectively. The maritime ecoregions PSM timing were 2-3 times more sensitive to warming and drying versus the interior mountain ecoregions. This work suggests that soil hydrology modifies the effects of earlier snowmelt on regional streamflow response and vegetation water stress.

  6. Application of a snowmelt-runoff model using LANDSAT data. [Dinwoody Creek Basin, Wyoming

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The snowmelt-runoff model developed for two small central European watersheds simulate daily streamflow on the 228 sq km Dinwoody Creek basin in Wyoming, using snowcover extent for LANDSAT and conventionally measured temperature and precipitation. For the six-month snowmelt seasons of 1976 and 1974, the simulated seasonal runoff volumes were within 5 and 1%, respectively, of the measured runoff. Also the daily fluctuations of discharge were simulated to a high degree by the model. Thus far the limiting basin size for applying the model has not been reached, and improvements can be expected if the hydrometeorological data can be obtained from a station inside the basin. LANDSAT provides an efficient way to obtain the critical snowcover input parameter required by the model.

  7. Interannual variability of snowmelt in the Sierra Nevada and Rocky Mountains, United States: examples from two alpine watersheds

    USGS Publications Warehouse

    Jepsen, Steven M.; Molotch, Noah P.; Williams, Mark W.; Rittger, Karl E.; Sickman, James O.

    2012-01-01

    The distribution of snow and the energy flux components of snowmelt are intrinsic characteristics of the alpine water cycle controlling the location of source waters and the effect of climate on streamflow. Interannual variability of these characteristics is relevant to the effect of climate change on alpine hydrology. Our objective is to characterize the interannual variability in the spatial distribution of snow and energy fluxes of snowmelt in watersheds of a maritime setting, Tokopah Basin (TOK) in California's southern Sierra Nevada, and a continental setting, Green Lake 4 Valley (GLV4) in Colorado's Front Range, using a 12 year database (1996–2007) of hydrometeorological observations and satellite-derived snow cover. Snowpacks observed in GLV4 exhibit substantially greater spatial variability than in TOK (0.75 versus 0.28 spatial coefficient of variation). In addition, modeling results indicate that the net turbulent energy flux contribution to snowmelt in GLV4 is, on average, 3 times greater in magnitude (mean 29% versus 10%) and interannual variability (standard deviation 17% versus 6%) than in TOK. These energy flux values exhibit strong seasonality, increasing as the melt season progresses to times later in the year (R2 = 0.54–0.77). This seasonality of energy flux appears to be associated with snowmelt rates that generally increase with onset date of melt (0.02 cm d-2). This seasonality in snowmelt rate, coupled to differences in hydrogeology, may account for the observed differences in correspondence between the timing of snowmelt and timing of streamflow in these watersheds.

  8. Improvement of Operational Streamflow Prediction with MODIS-derived Fractional Snow Covered Area Observations

    NASA Astrophysics Data System (ADS)

    Bender, S.; Burgess, A.; Goodale, C. E.; Mattmann, C. A.; Miller, W. P.; Painter, T. H.; Rittger, K. E.; Stokes, M.; Werner, K.

    2013-12-01

    Water managers in the western United States depend heavily on the timing and magnitude of snowmelt-driven runoff for municipal supply, irrigation, maintenance of environmental flows, and power generation. The Colorado Basin River Forecast Center (CBRFC) of the National Weather Service issues operational forecasts of snowmelt-driven streamflow for watersheds within the Colorado River Basin (CRB) and eastern Great Basin (EGB), across a wide variety of scales. Therefore, the CBRFC and its stakeholders consider snowpack observations to be highly valuable. Observations of fractional snow covered area (fSCA) from satellite-borne instrumentation can better inform both forecasters and water users with respect to subsequent snowmelt runoff, particularly when combined with observations from ground-based station networks and/or airborne platforms. As part of a multi-year collaborative effort, CBRFC has partnered with the Jet Propulsion Laboratory (JPL) under funding from NASA to incorporate observations of fSCA from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) into the operational CBRFC hydrologic forecasting and modeling process. In the first year of the collaboration, CBRFC and NASA/JPL integrated snow products into the forecasting and decision making processes of the CBRFC and showed preliminary improvement in operational streamflow forecasts. In late 2012, CBRFC and NASA/JPL began retrospective analysis of relationships between the MODIS Snow Covered Area and Grain size (MODSCAG) fSCA and streamflow patterns for several watersheds within the CRB and the EGB. During the 2013 snowmelt runoff season, CBRFC forecasters used MODIS-derived fSCA semi-quantitatively as a binary indicator of the presence or lack of snow. Indication of the presence or lack of snow by MODIS assisted CBRFC forecasters in determining the cause of divergence between modeled and recently observed streamflow. Several examples of improved forecasts from across the CRB and EGB, informed by

  9. Streamflow characteristics of small tributaries of Rock Creek, Milk River basin, Montana, base period water years 1983-87

    USGS Publications Warehouse

    Parrett, Charles; Hull, J.A.

    1990-01-01

    Five streamflow-gaging stations were installed in the Rock Creek basin north of the Milk River near Hinsdale, Montana. Streamflow was monitored at these stations and at an existing gaging station upstream on Rock Creek from May 1983 through September 1987. The data collected were used to describe the flow characteristics of four small tributary streams. Annual mean streamflow ranges from 2.8 to 57 cu ft/sec in the mainstem and from 0 to 0.60 cu ft/sec in the tributaries. Monthly mean streamflow ranged from 0 to 528 cu ft/sec in Rock Creek and from zero to 5.3 cu ft/sec in the four tributaries. The six gaged sites show similar patterns of daily mean streamflow during periods of large runoff, but substantial individual variations during periods of lesser runoff. During periods of lesser runoff , the small tributaries may have small daily mean streamflows. At other times, daily mean streamflow at the two mainstem sites decreased downstream. Daily mean streamflow in the tributaries appears to be closely related to daily mean streamflow in the mainstem only during periods of substantial area-wide runoff. Thus, streamflow in the tributaries resulting from local storms or local snowmelt may not contribute to streamflow in the mainstem. (USGS)

  10. Relation of urban land-use and dry-weather storm and snowmelt flow characteristics to stream-water quality, Shunganunga Creek basin, Topeka, Kansas

    USGS Publications Warehouse

    Pope, L.M.; Bevans, H.E.

    1984-01-01

    Water-quality characteristics of streams draining Topeka, Kansas , and the Shunganunga Creek basin were investigated from October , 1979, through November 1981, to determine the effects of runoff from urban areas. Characteristics were determined at six sites and summarized statistically for three streamflow conditions-dry weather, storm, and snowmelt. Median concentrations of trace metals and nutrients were greater in storm streamflow than in dry-weather streamflow. Regression equations were developed to estimate median concentrations of total lead and zinc in storm streamflow from the percentage of drainage area in residential plus commercial land-use areas and from street density. Median concentrations of dissolved sodium, chloride, and solids were considerably greater in snowmelt streamflow than in dry-weather streamflow. Regression equations were also developed to estimate median concentrations of dissolved sodium, chloride, and solids from the summation of percentages of the drainage area in residential, commercial, and industrial land-use areas and from street density. Multiple-regression analysis relating storm-runoff volumes and average constituent concentrations to land-use and storm charactersitcs produced significant relations for storm-runoff volume, total lead, total zinc, and suspended sediment. (USGS)

  11. Uncertainty estimation and reconstruction of historical streamflow records

    NASA Astrophysics Data System (ADS)

    Kuentz, A.; Mathevet, T.; Perret, C.; Andréassian, V.

    2012-04-01

    streamflow series: (1) daily punctual measurements of water height at the gauging station; (2) automatic graphical record of water height and manual sampling of the limnigraphs; (3) automatic numerical record of the height at an hourly timestep, conversion to streamflow and calculation of the daily streamflow by mean of the 24 hourly values (current method). By simulating and comparing the two fist methods with the current one on a panel of gauging stations, we show that the impact of the elaboration method of the streamflow series can be important. What we firstly consider as continuous long series is in fact a juxtaposition of several series which characteristics can be really different. The first method can bias up to 20% the value of daily streamflow compared to a daily mean streamflow, depending on the measurement time and the season. The uncertainty strongly depends on the watershed hydrological regime and the dominant streamflow processes occurring (snowmelt influence or runoff). The most important impacts of this method are observed on mountainous watersheds due to the daily streamflow cycle induced by snowmelt. To a lesser extent, this method can also biais the interannual mean. A correction technique for this type of series is proposed. The second method seems to have a lower impact (around 2%) on the final result, but the bias can still be important (up to 15%) for some watersheds and some streamflow ranges.

  12. THE ABCS OF SNOWMELT: A TOPOGRAPHICALLY FACTORIZED ENERGY COMPONENT SNOWMELT MODEL. (R824784)

    EPA Science Inventory

    Because of the crucial role snowmelt plays in many watersheds around the world, it is important to understand and accurately quantify the melt process. As such, numerous mathematical models attempting to describe and predict snowmelt have arisen. There are two main categories of ...

  13. Determination of hydrologic pathways during snowmelt for alpine/subalpine basins, Rocky Mountain National Park, Colorado

    USGS Publications Warehouse

    Sueker, J.K.; Ryan, J.N.; Kendall, C.; Jarrett, R.D.

    2000-01-01

    Alpine/subalpine ecosystems in Rocky Mountain National Park may be sensitive to atmospherically derived acidic deposition. Two- and three-component hydrograph separation analyses and correlation analyses were performed for six basins to provide insight into streamflow generation during snowmelt and to assess basin sensitivity to acidic deposition. Three-component hydrograph separation results for five basins showed that streamflow contained from 42 to 57% direct snowmelt runoff, 37 to 54% subsurface water, and 4 to 13% direct rain runoff for the May through October 1994 study period. Subsurface contributions were 89% of total flow for the sixth basin. The reliability of hydrograph separation model assumptions was explored. Subsurface flow was positively correlated with the amount of surficial material in a basin and was negatively correlated with basin slope. Basins with extensive surficial material and shallow slopes are less susceptible to ecosystem changes due to acidic deposition than basins with less surficial material and steeper slopes. This study was initiated to expand the intensive hydrologic research that has been conducted in Loch Vale basin to a more regional scale.

  14. Episodic acidification of Adirondack lakes during snowmelt

    SciTech Connect

    Schaefer, D.A.; Driscoll, C.T.; Van Dreason, R.; Yatsko, C.P.

    1990-07-01

    Maximum values of acid neutralizing capacity (ANC) in Adirondack, New York lake outlets generally occur during summer and autumn. During spring snowmelt, transport of acidic water through acid-sensitive watersheds causes depression of upper lake water ANC. In some systems lake outlet ANC reaches negative values. The authors examined outlet water chemistry from II Adirondack lakes during 1986 and 1987 snowmelts. In these lakes, SO concentrations were diluted during snowmelt and did not depress ANC. For lakes with high baseline ANC values, springtime ANC depressions were primarily accompanied by basic cation dilution. For lakes with low baseline ANC, No increases dominated ANC depressions. Lakes with intermediate baseline ANC were affected by both processes and exhibited larger ANC depressions. Ammonium dilution only affected wetland systems. A model predicting a linear relationship between outlet water ANC minima and autumn ANC was inappropriate. To assess watershed response to episodic acidification, hydrologic flow paths must be considered. (Copyright (c) 1990 by the American Geophysical Union.)

  15. Quantifying effects of climate change on the snowmelt-dominated groundwater resources of northern New England

    USGS Publications Warehouse

    Dudley, Robert W.; Hodgkins, Glenn A.; Shanley, James B.; Mack, Thomas J.

    2010-01-01

    Recent U.S. Geological Survey (USGS) climate studies in New England have shown substantial evidence of hydrologic changes during the last 100 years, including trends toward earlier snowmelt runoff, decreasing occurrence of river ice, and decreasing winter snowpack. These studies are being expanded to include investigation of trends in groundwater levels and fluctuations. Groundwater is an important drinking-water source throughout northern New England (Maine, New Hampshire, and Vermont). The USGS is currently investigating whether or not groundwater recharge from snowmelt and precipitation exhibits historical trends. In addition to trend-testing, groundwater resources also will be analyzed by relating groundwater-level changes to the large year-to-year variability in weather conditions. Introduction The USGS has documented many seasonal climate-related changes in the northeastern United States that have occurred during the last 30 to 150 years. These changes include earlier snowmelt runoff in the late winter and early spring, decreasing duration of ice on rivers and lakes, decreasing ratio of snowfall to total precipitation, and denser and thinner late-winter snowpack. All of these changes are consistent with warming winter and spring air temperatures (Dudley and Hodgkins, 2002; Hodgkins and others, 2002; Huntington and others, 2004; Hodgkins and others, 2005; Hodgkins and Dudley, 2006a; Hodgkins and Dudley, 2006b). Climate-model projections for the Northeast indicate air-temperature warming, earlier snowmelt runoff, increases in annual evaporation, and decreased low streamflows (Hayhoe and others, 2007). The contribution and timing of spring snowmelt to groundwater recharge is particularly important to groundwater resources in the northeastern United States where aquifers typically consist of thin sediments overlying crystalline bedrock with relatively little storage capacity (Mack, 2009). Following spring recharge, groundwater slowly flows into streams throughout

  16. Streamflow variation due to glacier melting and climate change in upstream Heihe River Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Wu, Feng; Zhan, Jinyan; Wang, Zhan; Zhang, Qian

    Streamflow simulation is often challenging in mountainous watersheds because of incomplete hydrological models, irregular topography, immeasurable snowpack or glacier, and low data resolution. In this study, a semi-distributed conceptual hydrological model (SWAT-Soil Water Assessment Tool) coupled with a glacier melting algorithm was applied to investigate the sensitivity of streamflow to climatic and glacial changes in the upstream Heihe River Basin. The glacier mass balance was calculated at daily time-step using a distributed temperature-index melting and accumulation algorithm embedded in the SWAT model. Specifically, the model was calibrated and validated using daily streamflow data measured at Yingluoxia Hydrological Station and decadal ice volume changes derived from survey maps and remote sensing images between 1960 and 2010. This study highlights the effects of glacier melting on streamflow and their future changes in the mountainous watersheds. We simulate the contribution of glacier melting to streamflow change under different scenarios of climate changes in terms of temperature and precipitation dynamics. The rising temperature positively contributed to streamflow due to the increase of snowmelt and glacier melting. The rising precipitation directly contributes to streamflow and it contributed more to streamflow than the rising temperature. The results show that glacial meltwater has contributed about 3.25 billion m3 to streamflow during 1960-2010. However, the depth of runoff within the watershed increased by about 2.3 mm due to the release of water from glacial storage to supply the intensified evapotranspiration and infiltration. The simulation results indicate that the glacier made about 8.9% contribution to streamflow in 2010. The research approach used in this study is feasible to estimate the glacial contribution to streamflow in other similar mountainous watersheds elsewhere.

  17. A hydrometric and geochemical approach to test the transmissivity feedback hypothesis during snowmelt

    NASA Astrophysics Data System (ADS)

    Kendall, K. A.; Shanley, J. B.; McDonnell, J. J.

    1999-07-01

    To test the transmissivity feedback hypothesis of runoff generation, surface and subsurface waters were monitored and sampled during the 1996 snowmelt at various topographic positions in a 41 ha forested headwater catchment at Sleepers River, Vermont. Two conditions that promote transmissivity feedback existed in the catchment during the melt period. First, saturated hydraulic conductivity increased toward land surface, from a geometric mean of 3.6 mm h -1 in glacial till to 25.6 mm h -1 in deep soil to 54.0 mm h -1 in shallow soil. Second, groundwater levels rose to within 0.3 m of land surface at all riparian sites and most hillslope sites at peak melt. The importance of transmissivity feedback to streamflow generation was tested at the catchment scale by examination of physical and chemical patterns of groundwater in near-stream (discharge) and hillslope (recharge/lateral flow) zones, and within a geomorphic hollow (convergent flow). The presence of transmissivity feedback was supported by the abrupt increase in streamflow as the water table rose into the surficial, transmissive zone; a flattening of the groundwater level vs. streamflow curve occurred at most sites. This relation had a clockwise hysteresis (higher groundwater level for given discharge on rising limb than at same discharge on falling limb) at riparian sites, suggesting that the riparian zone was the dominant source area during the rising limb of the melt hydrograph. Hysteresis was counterclockwise at hillslope sites, suggesting that hillslope drainage controlled the snowmelt recession. End member mixing analysis using Ca, Mg, Na, dissolved organic carbon (DOC), and Si showed that stream chemistry could be explained as a two-component mixture of groundwater high in base cations and an O-horizon/overland flow water high in DOC. The dominance of shallow flow paths during events was indicated by the high positive correlation of DOC with streamflow ( r2=0.82). Despite the occurrence of transmissivity

  18. Verification of temperature, precipitation, and streamflow forecasts from the NOAA/NWS Hydrologic Ensemble Forecast Service (HEFS): 2. Streamflow verification

    NASA Astrophysics Data System (ADS)

    Brown, James D.; He, Minxue; Regonda, Satish; Wu, Limin; Lee, Haksu; Seo, Dong-Jun

    2014-11-01

    -GFS accounts for the majority of skill in the CNRFC basins. This is associated with the greater predictability of large storms in the North Coast Ranges during the winter months. In CBRFC, much of the skill in the streamflow forecasts originates from the hydrologic modeling and the EnsPost, particularly during the snowmelt period. In AB- and MA-RFCs, the contributions from the MEFP and the EnsPost are more variable. This paper summarizes the verification results, describes the expected performance and limitations of the HEFS for short- to medium-range streamflow forecasting, and provides recommendations for future research.

  19. Variations in northern Sierra Nevada streamflow. Implications of climate change

    USGS Publications Warehouse

    Pupacko, A.

    1993-01-01

    Historical records of streamflow for an eastward- and a westward-draining stream in the northern Sierra Nevada have been analyzed for evidence of changes in runoff characteristics and patterns of variability. A trend of increasing and more variable winter streamflow began in the mid-1960s. Mean monthly streamflow during December through March was substantially greater for water years 1965-1990 compared to water years 1939-1964. Increased winter and early-spring streamflow during the later period is attributed to small increases in temperature, which increase the rain-to-snow ratio at lower altitudes and cause the snowpack to melt earlier in the season at higher altitudes. The timing of snowmelt runoff on the western slope of the Sierra Nevada is more sensitive than it is on the eastern slope to changes in temperature, owing to predominantly lower altitudes on the west side. This difference in sensitivity suggests that basins on the east side of the Sierra Nevada have a more reliable water supply (as snow storage) than western-slope basins during warming trends.

  20. EPISODIC ACIDIFICATION OF ADIRONDACK LAKES DURING SNOWMELT

    EPA Science Inventory

    Maximum values of acid neutralizing capacity (ANC) in Adirondack, New York lake outlets generally occur during summer and autumn. During spring snowmelt, transport of acidic water through acid-sensitive watersheds causes depression of upper lake water ANC. n some systems lake out...

  1. Snowmelt Runoff Model (SRM) User's Manual

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This 2008 edition of the User’s Manual presents a new computer program, the Windows Version 1.11 of the Snowmelt Runoff Model (WinSRM). The popular Version 4 is also preserved in the Appendix because it is still in demand to be used within its limits. The Windows version adds new capabilities: it ac...

  2. The effect of frozen soil on snowmelt runoff at Sleepers River, Vermont

    USGS Publications Warehouse

    Shanley, J.B.; Chalmers, A.

    1999-01-01

    Soil frost depth has been monitored at the Sleepers River Research Watershed in northeastern Vermont since 1984. Soil frost develops every winter, particularly in open fields, but its depth varies from year to year in inverse relation to snow depth. During the 15 years of record at a benchmark mid-elevation open site, the annual maximum frost depth varied from 70 to 390 mm. We empirically tested the hypothesis that frozen soil prevents infiltration and recharge, thereby causing an increased runoff ratio (streamflow/(rain + snowmelt)) during the snowmelt hydrograph rise and a decreased runoff ratio during snowmelt recession. The hypothesis was not supported at the 111 km2 W-5 catchment; there was no significant correlation of the runoff ratio with the seasonal maximum frost depth for either the pre-peak or post-peak period. In an analysis of four events, however, the presence of frost promoted a large and somewhat quicker response to rainfall relative to the no-frost condition, although snow cover caused a much greater time-to-peak regardless of frost status. For six years of flow and frost depth measured at the 59 ha agricultural basin W-2, the hypothesis appeared to be supported. The enhancement of runoff due to soil frost is evident on small plots and in extreme events, such as rain on frozen snow-free soil. In the northeastern USA and eastern Canada, the effect is often masked in larger catchments by several confounding factors, including storage of meltwater in the snowpack, variability in snowmelt timing due to elevational and aspect differences, interspersed forested land where frost may be absent, and the timing of soil thawing relative to the runoff peak.Soil frost depth has been monitored at the Sleepers River Research Watershed in northeastern Vermont since 1984. Soil frost develops every winter, particularly in open fields, but its depth varies greatly from year to year in inverse relation to snow depth. During the 15 years of record at a benchmark mid

  3. ADATSA Follow-Up Study of Extended Outpatient Care: A Comparison of 90 Days versus 180 Days of Outpatient Treatment for Clients of Washington State's Alcoholism and Drug Addiction Treatment and Support Act.

    ERIC Educational Resources Information Center

    Van Der Hyde, Vincent A.; And Others

    This study was designed to compare outcomes for two groups of alcohol and substance abuse clients (N=230): a control group assigned to regular 90 days of outpatient treatment, and an experimental group assigned to 180 days of extended outpatient care. Outcomes were compared in the following nine categories: (1) relapse, measured as reported…

  4. A hydrogeologic framework for characterizing summer streamflow sensitivity to climate warming in the Pacific Northwest, USA

    NASA Astrophysics Data System (ADS)

    Safeeq, M.; Grant, G. E.; Lewis, S. L.; Kramer, M. G.; Staab, B.

    2014-09-01

    Summer streamflows in the Pacific Northwest are largely derived from melting snow and groundwater discharge. As the climate warms, diminishing snowpack and earlier snowmelt will cause reductions in summer streamflow. Most regional-scale assessments of climate change impacts on streamflow use downscaled temperature and precipitation projections from general circulation models (GCMs) coupled with large-scale hydrologic models. Here we develop and apply an analytical hydrogeologic framework for characterizing summer streamflow sensitivity to a change in the timing and magnitude of recharge in a spatially explicit fashion. In particular, we incorporate the role of deep groundwater, which large-scale hydrologic models generally fail to capture, into streamflow sensitivity assessments. We validate our analytical streamflow sensitivities against two empirical measures of sensitivity derived using historical observations of temperature, precipitation, and streamflow from 217 watersheds. In general, empirically and analytically derived streamflow sensitivity values correspond. Although the selected watersheds cover a range of hydrologic regimes (e.g., rain-dominated, mixture of rain and snow, and snow-dominated), sensitivity validation was primarily driven by the snow-dominated watersheds, which are subjected to a wider range of change in recharge timing and magnitude as a result of increased temperature. Overall, two patterns emerge from this analysis: first, areas with high streamflow sensitivity also have higher summer streamflows as compared to low-sensitivity areas. Second, the level of sensitivity and spatial extent of highly sensitive areas diminishes over time as the summer progresses. Results of this analysis point to a robust, practical, and scalable approach that can help assess risk at the landscape scale, complement the downscaling approach, be applied to any climate scenario of interest, and provide a framework to assist land and water managers in adapting to

  5. Toward improving streamflow prediction in the Upper Colorado River Basin via assimilating bias-adjusted satellite snow depth retrievals

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Peters-Lidard, C. D.; Kumar, S.; Arsenault, K. R.; Mocko, D. M.

    2014-12-01

    In snowmelt-driven river systems, it is critical to enable reliable predictions of the spatiotemporal variability in the seasonal snowpack in order to support local and regional water management. Previous studies have shown that improved snow predictions can be achieved by assimilating bias corrected snow depth retrievals from satellite-based passive microwave (PMW) sensors. However, improved snow predictions do not necessarily always translate into improved predictions of streamflow on which water management heavily relies. In this presentation, we explore how the existing bias correction strategy based on the optimal interpolation algorithm can be enhanced to produce an improved satellite-gauge blended snow depth product, which, when assimilated into a distributed snowmelt-runoff model, can lead to consistently improved streamflow predictions. The methodology is applied to the bias reduction of the snow depth estimates from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E), which is then assimilated into the Noah land surface model via an ensemble Kalman Filter (EnKF) for streamflow prediction in the Upper Colorado River Basin. Our results indicate that using observations from high-elevation stations (e.g., the Snow Telemetry (SNOTEL) stations) and terrain aspect information in the bias correction process is critically important in achieving desirable streamflow predictions. Incorporating snow cover information (e.g., from the Moderate Resolution Imaging Spectroradiometer (MODIS)) into bias correction can further improve the streamflow results. However, increasing the spatial resolution of bias correction tends to have mixed results on streamflow prediction.

  6. Changes in the magnitude of annual and monthly streamflows in New England, 1902-2002

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Dudley, Robert W.

    2005-01-01

    Selected annual and monthly streamflow statistics for 27 streamflow-gaging stations in New England were computed and tested for changes over time. These 27 stations were considered to be free of substantial human influences such as regulation, diversion, and land use-changes and have an average of 71 years of record. The longest streamflow record extended from 1902 to 2002. March mean streamflows increased significantly over time (Mann-Kendall test, p < 0.1) at 14 streamflow-gaging stations in northern New England, primarily in northern or mountainous sections of Maine, New Hampshire, and Vermont. March mean flows increased by 76 to 185 percent at the seven stations with the longest continuous records in areas of New England with the largest seasonal snowpack depths. These streamflow-gaging stations had continuous records from the late 1920's and the early 1930s through 2002. May mean streamflows significantly decreased at 10 stations in northern or mountainous sections of Maine and New Hampshire. May mean flows decreased by 9 to 46 percent at the seven stations with the longest continuous records. Despite the fact that March percentage increases were much larger than May percentage decreases, March streamflow increases (in cubic feet per second) were smaller than May decreases, except at one streamflow-gaging station. Increased March and April air temperatures over time may have caused earlier snowmelt and thus increased streamflows in March and decreased streamflows in May. There were no significant changes over time in annual mean streamflows at the 27 stations; however, there were significant increases over time in various annual percentile streamflows (minimum, 25th percentile, median, 75th percentile, or maximum flows) at 22 of the stations. This indicates that flows increased over time at many streams in New England, but the increase was not enough to have caused significant changes in annual mean flows. October mean streamflows increased significantly at

  7. Analysis of runoff generation during rainfall and snowmelt events in an Alpine catchment based on isotopic and electrical conductivity data

    NASA Astrophysics Data System (ADS)

    Penna, Daniele; van Meerveld, Ilja; Zuecco, Giulia; Dalla Fontana, Giancarlo; Borga, Marco

    2015-04-01

    Alpine catchments are valuable sources of fresh water. However, compared to lower altitude catchments, our knowledge of the hydrologic behavior of high-elevation catchments is still relatively poor. We, therefore, set out to identify the dominant controls on runoff generation in the 0.14-km2 Bridge Creek Catchment in the Italian Dolomites (Central-Eastern Alps). Stable isotopes of water and electrical conductivity (EC) data, coupled with hydrometric measurements (precipitation, streamflow, spatially-distributed shallow groundwater and soil moisture at different depths), were collected during nine rainfall-runoff events and six snowmelt-runoff events in spring, summer and autumn of 2010-2012. Specifically, we aimed to i) quantify the relative contributions of event water to streamflow and detect the factors affecting the event water fractions in the stream; ii) identify the dominant runoff pathways for event and pre-event water to the stream; and iii) determine if the selection of pre-event water samples significantly affects the results of the isotope-based hydrograph separation analyses. The traditional two-component hydrograph separation technique was applied to deuterium data in two ways: i) assuming that the stream water sample taken prior to the event represented the isotopic composition of pre-event water , or ii) assuming that the average composition of stream water samples taken during baseflow conditions at different times of the year represented the pre-event water composition. For rainfall events, the hydrograph separation results for the two methods were very similar (root mean squared error=0.3 l/s) but for snowmelt events they significantly differed, especially when the event water runoff was high (root mean squared error=1.8 l/s). This was due to residual snowmelt (particularly late in the melt season) contained in stream water that influenced the isotopic composition of the stream between melt events. The pre-event water fraction dominated

  8. Warming spring air temperatures, but delayed spring streamflow in an Arctic headwater basin

    NASA Astrophysics Data System (ADS)

    Shi, Xiaogang; Marsh, Philip; Yang, Daqing

    2015-06-01

    This study will use the Mann-Kendall (MK) non-parametric trend test to examine timing changes in spring (early May to the end of June) streamflow records observed by the Water Survey of Canada during 1985-2011 in an Arctic headwater basin in the Western Canadian Arctic. The MK test shows a general delay in the five timing measures of springtime streamflow, which are based on the 5 percentile (Q5), 10 percentile (Q10), 50 percentile (Q50), 90 percentile (Q90), and 95 percentile (Q95) dates of spring runoff, respectively. However, much stronger trend signals were clearly noted for the high percentiles than that for the low and middle percentiles, indicating different effects of hydroclimate processes working on the timing of springtime streamflow. In contrast, the earlier snowmelt onset derived from daily mean temperatures was found over the 27-year study period. In addition, multiple relationships were correlated between these five timing measures of spring runoff and five hydroclimate indicators (total snowfall, snowmelt onset, spring temperature fluctuation, spring rainfall, and spring rainfall timing) in order to identify possible causes on the changes of springtime streamflow timing. The results indicate that the differences are due to the contradictory effects of winter-spring air temperature changes, temperature fluctuation during the melting period, and spring rainfall to spring runoff. The earlier snowmelt onset, which is attributed to the winter-spring warming, and spring temperature fluctuation that works in the opposite way, result in the minor timing changes of Q5, Q10, and Q50. The increase in spring rainfall and its delayed timing have a significant impact on the dates of Q90 and Q95. Moreover, the decreased total snow accumulation over the winter season only has a minor influence on the timing of springtime streamflow.

  9. A hydrometric and geochemical approach to test the transmissivity feedback hypothesis during snowmelt

    USGS Publications Warehouse

    Kendall, K.A.; Shanley, J.B.; McDonnell, Jeffery J.

    1999-01-01

    To test the transmissivity feedback hypothesis of runoff generation, surface and subsurface waters were monitored and sampled during the 1996 snowmelt at various topographic positions in a 41 ha forested headwater catchment at Sleepers River, Vermont. Two conditions that promote transmissivity feedback existed in the catchment during the melt period. First, saturated hydraulic conductivity increased toward land surface, from a geometric mean of 3.6 mm h-1 in glacial till to 25.6 mm h-1 in deep soil to 54.0 mm h-1 in shallow soil. Second, groundwater levels rose to within 0.3 m of land surface at all riparian sites and most hillslope sites at peak melt. The importance of transmissivity feedback to streamflow generation was tested at the catchment scale by examination of physical and chemical patterns of groundwater in near-stream (discharge) and hillslope (recharge/lateral flow) zones, and within a geomorphic hollow (convergent flow). The presence of transmissivity feedback was supported by the abrupt increase in streamflow as the water table rose into the surficial, transmissive zone; a flattening of the groundwater level vs. streamflow curve occurred at most sites. This relation had a clockwise hysteresis (higher groundwater level for given discharge on rising limb than at same discharge on falling limb) at riparian sites, suggesting that the riparian zone was the dominant source area during the rising limb of the melt hydrograph. Hysteresis was counterclockwise at hillslope sites, suggesting that hillslope drainage controlled the snowmelt recession. End member mixing analysis using Ca, Mg, Na, dissolved organic carbon (DOC), and Si showed that stream chemistry could be explained as a two-component mixture of groundwater high in base cations and an O-horizon/overland flow water high in DOC. The dominance of shallow flow paths during events was indicated by the high positive correlation of DOC with streamflow (r2 = 0.82). Despite the occurrence of transmissivity

  10. Relationship Between Satellite-Derived Snow Cover and Snowmelt-Runoff Timing and Stream Power in the Wind River Range, Wyoming

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Foster, James L.; DiGirolamo, Nicolo E.; Riggs, George A.

    2010-01-01

    Earlier onset of springtime weather including earlier snowmelt has been documented in the western United States over at least the last 50 years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for streamflow management. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud- gap-filled (CGF) map products and 30 years of discharge and meteorological station data are studied. Streamflow data from six streams in the WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed using MODIS snow-cover maps within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period. MODIS-derived snow cover (percent of basin covered) measured on 30 April explains over 89% of the variance in discharge for maximum monthly streamflow in the decade of the 2000s using Spearman rank correlation analysis. We also investigated stream power for Bull Lake Creek Above Bull Lake from 1970 to 2009; a statistically-significant end toward reduced stream power was found (significant at the 90% confidence level). Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature measured during the 40-year study period. The

  11. Relationship Between Satellite-Derived Snow Cover and Snowmelt-Runoff Timing and Stream Power in the Wind River Range, Wyoming

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Foster, James L.; Riggs, George A.; DiGirolano, Nocolo E.

    2010-01-01

    Earlier onset of springtime weather including earlier snowmelt has been documented in the western United States over at least the last 50 years. Because the majority (>70%) of the water supply in the western U.S. comes from snowmelt, analysis of the declining spring snowpack (and shrinking glaciers) has important implications for streamflow management. The amount of water in a snowpack influences stream discharge which can also influence erosion and sediment transport by changing stream power, or the rate at which a stream can do work such as move sediment and erode the stream bed. The focus of this work is the Wind River Range (WRR) in west-central Wyoming. Ten years of Moderate-Resolution Imaging Spectroradiometer (MODIS) snow-cover, cloud- gap-filled (CGF) map products and 30 years of discharge and meteorological station a are studied. Streamflow data from six streams in the WRR drainage basins show lower annual discharge and earlier snowmelt in the decade of the 2000s than in the previous three decades, though no trend of either lower streamflow or earlier snowmelt was observed using MODIS snow-cover maps within the decade of the 2000s. Results show a statistically-significant trend at the 95% confidence level (or higher) of increasing weekly maximum air temperature (for three out of the five meteorological stations studied) in the decade of the 1970s, and also for the 40-year study period. MODIS- derived snow cover (percent of basin covered) measured on 30 April explains over 89% of the variance in discharge for maximum monthly streamflow in the decade of the 2000s using Spearman rank correlation analysis. We also investigated stream power for Bull Lake Creek Above Bull Lake from 1970 to 2009; a statistically-significant trend toward reduced stream power was found (significant at the 90% confidence level). Observed changes in streamflow and stream power may be related to increasing weekly maximum air temperature measured during the 40-year study period. The

  12. Evaluating climate change impacts in snowmelt basins

    NASA Astrophysics Data System (ADS)

    Gleick, Peter H.; Rango, Albert; Cooley, Keith

    The implications of global climate change for hydrology and water resources are likely to be complex, widespread, and significant for both natural ecosystems and society. Yet our understanding of these implications remains rudimentary despite considerable effort and research over the last decade. One of the most difficult hydrologic problems in this area is evaluating the impacts of climate change in hydrologic basins affected by snowfall and snowmelt, especially high-latitude and high-altitude watersheds. Many of these watersheds are the headwaters for major rivers and they often provide substantial amounts of water for human and ecosystem use. Evaluating the impacts of climate change in these basins will help us better understand how to improve the management and protection of our water resources systems. In April 1993, a roundtable workshop was held in Santa Fe, N. Mex., to discuss hydrologic models for evaluating the impacts of climate change in snowmelt basins.

  13. Relating Snowpack and Snowmelt in Weather Modified Watersheds

    NASA Astrophysics Data System (ADS)

    Tootle, G. A.; Pelle, A.; Oubeidillah, A.; Kerr, G.

    2014-12-01

    A 2008 editorial in Natureentitled "Change in the weather," it is stated that "a renewed push for scientific research into weather-modification technologies is long overdue." The editorial continues with "Today's rain-makers struggle with their own credibility issues. They do have well established methods for seeding clouds….. weather-modification supporters face a perceived negative bias in the scientific community….. There has yet to be the definitive experiment that settles exactly how well cloud seeding… works (or not)." The editorial concludes with "Other countries, such as the United States, have simply given up; the most promising experiment in America is run not by the federal government but by the state of Wyoming....which is being evaluated by experts from the National Center for Atmospheric Research (NCAR). That's the type of targeted and rigorous study that needs to be done in weather modification, but it took Wyoming to do it." The motivation for weather modification operations is to increase water supply (streamflow) due to increased snowpack. NCAR will complete their evaluation in Fall 2014 that will provide, with uncertainty, the anticipated increase (percent) in snowpack due to cloud seeding. The majority of the cloud seeding for the Wyoming Weather Modification Pilot Project was performed in the North Platte River Basin (NPRB). Researchers from the University of Wyoming, in cooperation with NCAR, analyzed historic meteorological data for the cloud seeding season (November 15th to April 15th) for eight years (2001-2008) to determine "seedable" periods. Using this data combined with the anticipated increase (percent with uncertainty), University of Alabama researchers developed two models (statistical and hydrologic) for the North Brush Creek watershed which is located within the NPRB. The statistical model related snowpack (Snow Water Equivalent) from SNOTEL stations to snowmelt using the Partial Least Squares Regression technique. The

  14. Impact of the snow cover estimation method on the Snowmelt Runoff Model performance in the moroccan High Atlas Mountains

    NASA Astrophysics Data System (ADS)

    Boulet, G.; Boudhar, A.; Hanich, L.; Duchemin, B.; Chehbouni, G.; Berjamy, B.

    2009-04-01

    In the centre of Morocco, the High-Atlas range represents the most important water storage for the neighbouring arid plains through liquid but also solid precipitation. Snow in this mountain may represent an important source of water for downstream populations especially in spring and early summer. Therefore, monitoring efficiently the evolution of snow cover and snow depth is essential to properly managing the water resources of this region. In this context, five main tributary watersheds of the High-Atlas range were selected to evaluate the performance of the Snowmelt Runoff Modelling model using snow maps obtained from the SPOT-VGT satellite as input data. Before identifying the optimal parameters of the model in a systematic calibration procedure, a parameter sensitivity analysis and an investigation of the eventual equifinality problems are discussed. Calibration is performed in 2005 during the main snowfall/snowmelt season (from January 1 to May 31) and validation is carried out for the same season between 2002 and 2005. In order to quantify the added-value of remotely sensed snow cover extent, streamflow is simulated using SRM together with two Snow Cover Area (SCA) estimates: SCA estimated from remote sensing data, and SCA generated from scarce meteorological data, using a simple degree day method. Snow depletion curves developed from both methods were generally comparable in all watersheds, and satisfactory streamflow simulations were obtained at annual timescales using both snow-cover products. However, using snow cover information derived from remote sensing data can significantly improve streamflow prediction for individual interstorm periods were rainfall events are not observed by the network raingauges mostly located in the lower altitude, or when the temperature lapse rate is badly estimated. Finally, it was shown from the calibrated SRM model that roughly 25 % of streamflow arriving from the North sides of High Atlas is derived from snowmelt. In

  15. Hydrologic interactions in snow-melt runoff driven semiarid watersheds

    NASA Astrophysics Data System (ADS)

    Ochoa, C. G.; Guldan, S. J.; Fernald, A.; Tidwell, V. C.

    2013-12-01

    One of the main objectives of the study presented is to characterize the hydrologic interactions between the uplands and the downstream irrigated valleys in semiarid watersheds of the southwestern United States. A combined intensive field data collection and modeling approach is being used for better understanding the hydrologic connectivity between the headwaters and traditionally-irrigated valleys in three watersheds of northern New Mexico. Study results show a strong hydrologic connectivity between surface water and groundwater in the lower agricultural valleys that follows a seasonal pattern, driven primarily by irrigation contributions to the shallow aquifer. In one of the irrigated valleys, results showed that for separate irrigation events at the field scale, shallow aquifer recharge ranged from 1 to 230 mm and that for the cumulative irrigation season at the valley scale, aquifer recharge ranged from 1044 to 1350 mm yr-1. Runoff contributions from rain storms can also be a significant source of streamflow in these semiarid watersheds. A significant increase in river stage (0.3 m) was observed in response to runoff from a higher elevation frontal storm that yielded peak discharge of 17.9 m3 s-1 at a tributary monitoring station near the convergence with the Rio Grande. Also, preliminary results using a system dynamics model indicate a strong hydrologic connectivity between snow-melt driven runoff in the headwaters and the recharge of the shallow aquifer in the valley, mainly driven by the use of traditionally-irrigated agriculture systems. This study adds to the understanding of the interconnectedness of different hydrologic components and of the mechanisms of water distribution in semiarid landscapes.

  16. Examination of snowmelt over Western Himalayas using remote sensing data

    NASA Astrophysics Data System (ADS)

    Tiwari, Sarita; Kar, Sarat C.; Bhatla, R.

    2016-07-01

    Snowmelt variability in the Western Himalayas has been examined using remotely sensed snow water equivalent (SWE) and snow-covered area (SCA) datasets. It is seen that climatological snowfall and snowmelt amount varies in the Himalayan region from west to east and from month to month. Maximum snowmelt occurs at the elevation zone between 4500 and 5000 m. As the spring and summer approach and snowmelt begins, a large amount of snow melts in May. Strength and weaknesses of temperature-based snowmelt models have been analyzed for this region by computing the snowmelt factor or the degree-day factor (DDF). It is seen that average DDF in the Himalayas is more in April and less in July. During spring and summer months, melting rate is higher in the areas that have height above 2500 m. The region that lies between 4500 and 5000 m elevation zones contributes toward more snowmelt with higher melting rate. Snowmelt models have been developed to estimate interannual variations of monthly snowmelt amount using the DDF, observed SWE, and surface air temperature from reanalysis datasets. In order to further improve the estimate snowmelt, regression between observed and modeled snowmelt has been carried out and revised DDF values have been computed. It is found that both the models do not capture the interannual variability of snowmelt in April. The skill of the model is moderate in May and June, but the skill is relatively better in July. In order to explain this skill, interannual variability (IAV) of surface air temperature has been examined. Compared to July, in April, the IAV of temperature is large indicating that a climatological value of DDF is not sufficient to explain the snowmelt rate in April. Snow area and snow amount depletion curves over Himalayas indicate that in a small area at high altitude, snow is still observed with large SWE whereas over most of the region, all the snow has melted.

  17. Predicting streamflow regime metrics for ungauged streamsin Colorado, Washington, and Oregon

    NASA Astrophysics Data System (ADS)

    Sanborn, Stephen C.; Bledsoe, Brian P.

    2006-06-01

    Streamflow prediction in ungauged basins provides essential information for water resources planning and management and ecohydrological studies yet remains a fundamental challenge to the hydrological sciences. A methodology is presented for stratifying streamflow regimes of gauged locations, classifying the regimes of ungauged streams, and developing models for predicting a suite of ecologically pertinent streamflow metrics for these streams. Eighty-four streamflow metrics characterizing various flow regime attributes were computed along with physical and climatic drainage basin characteristics for 150 streams with little or no streamflow modification in Colorado, Washington, and Oregon. The diverse hydroclimatology of the study area necessitates flow regime stratification and geographically independent clusters were identified and used to develop separate predictive models for each flow regime type. Multiple regression models for flow magnitude, timing, and rate of change metrics were quite accurate with many adjusted R2 values exceeding 0.80, while models describing streamflow variability did not perform as well. Separate stratification schemes for high, low, and average flows did not considerably improve models for metrics describing those particular aspects of the regime over a scheme based on the entire flow regime. Models for streams identified as 'snowmelt' type were improved if sites in Colorado and the Pacific Northwest were separated to better stratify the processes driving streamflow in these regions thus revealing limitations of geographically independent streamflow clusters. This study demonstrates that a broad suite of ecologically relevant streamflow characteristics can be accurately modeled across large heterogeneous regions using this framework. Applications of the resulting models include stratifying biomonitoring sites and quantifying linkages between specific aspects of flow regimes and aquatic community structure. In particular, the results

  18. Remote sensing of snow cover and radiative forcing by dust in snow from MODIS toward distributed snowmelt modeling and water management

    NASA Astrophysics Data System (ADS)

    Painter, T. H.; Bryant, A. C.

    2011-12-01

    Accelerated snowmelt runoff frequently contributes to flooding in snow-dominated basins. For example, extreme dust deposition to the mountains of the Upper Colorado River basin in 2009 accelerated snowmelt with albedos as low as 0.33 and created unprecedented runoff rates, particularly in rivers of southern Colorado. Operationally, seasonal forecasts of snowmelt-generated streamflow are leveraged through empirical relations based on past snowmelt periods. These historical data show that climate is changing, but the changes reduce the reliability of the empirical relations. Moreover, they lack the capacity to ingest information on albedo changes that dramatically alter melt rates. Therefore optimal future management of snowmelt derived water resources will require explicit physical models driven by remotely sensed data. The most critical snow properties for modeling the energy and mass balance of the snow cover are its spatial extent and albedo. In this talk, we will explore the snow cover properties in the Upper Colorado River during the extreme dust year of 2009. We will use the MODIS Snow Covered Area and Grain size (MODSCAG) model and the MODIS Dust Radiative Forcing in Snow (MOD-DRFS) model to determine the spatial distribution of fractional snow cover and the impact of dust on snow net solar radiation, respectively, and determine the hydrologic response in the Uncompahgre and Rio Grande River basins. This work provides fundamental insights into the migration to energy balance approaches for water research and management to mitigate natural hazards such as flooding.

  19. Application and Evaluation of a Snowmelt Runoff Model in the Tamor River Basin, Eastern Himalaya Using a Markov Chain Monte Carlo (MCMC) Data Assimilation Approach

    NASA Technical Reports Server (NTRS)

    Panday, Prajjwal K.; Williams, Christopher A.; Frey, Karen E.; Brown, Molly E.

    2013-01-01

    Previous studies have drawn attention to substantial hydrological changes taking place in mountainous watersheds where hydrology is dominated by cryospheric processes. Modelling is an important tool for understanding these changes but is particularly challenging in mountainous terrain owing to scarcity of ground observations and uncertainty of model parameters across space and time. This study utilizes a Markov Chain Monte Carlo data assimilation approach to examine and evaluate the performance of a conceptual, degree-day snowmelt runoff model applied in the Tamor River basin in the eastern Nepalese Himalaya. The snowmelt runoff model is calibrated using daily streamflow from 2002 to 2006 with fairly high accuracy (average Nash-Sutcliffe metric approx. 0.84, annual volume bias <3%). The Markov Chain Monte Carlo approach constrains the parameters to which the model is most sensitive (e.g. lapse rate and recession coefficient) and maximizes model fit and performance. Model simulated streamflow using an interpolated precipitation data set decreases the fractional contribution from rainfall compared with simulations using observed station precipitation. The average snowmelt contribution to total runoff in the Tamor River basin for the 2002-2006 period is estimated to be 29.7+/-2.9% (which includes 4.2+/-0.9% from snowfall that promptly melts), whereas 70.3+/-2.6% is attributed to contributions from rainfall. On average, the elevation zone in the 4000-5500m range contributes the most to basin runoff, averaging 56.9+/-3.6% of all snowmelt input and 28.9+/-1.1% of all rainfall input to runoff. Model simulated streamflow using an interpolated precipitation data set decreases the fractional contribution from rainfall versus snowmelt compared with simulations using observed station precipitation. Model experiments indicate that the hydrograph itself does not constrain estimates of snowmelt versus rainfall contributions to total outflow but that this derives from the degree

  20. Stream water hydrochemistry as an indicator of carbon flow paths in Finnish peatland catchments during a spring snowmelt event.

    PubMed

    Dinsmore, Kerry J; Billett, Michael F; Dyson, Kirstie E; Harvey, Frank; Thomson, Amanda M; Piirainen, Sirpa; Kortelainen, Pirkko

    2011-10-15

    Extreme hydrological events are known to contribute significantly to total annual carbon export, the largest of which in Arctic and boreal catchments is spring snowmelt. Whilst previous work has quantified the export of carbon during snowmelt, the source of the carbon remains unclear. Here we use cation hydrochemistry to trace the primary flowpaths which govern the export of carbon during the snowmelt period; specifically we aim to examine the importance of snowpack meltwater to catchment carbon export. The study was carried out in two forested peatland (drained and undrained) catchments in Eastern Finland. Both catchments were characterised by base-poor stream water chemistry, with cation concentrations generally decreasing in response to increasing discharge. Streamflow during the snowmelt period was best described as a mixture of three sources: pre-event water, snowpack meltwater and a third dilute component we attribute to the upper snow layer which was chemically similar to recent precipitation. Over the study period, pre-event water contributed 32% and 43% of the total stream runoff in Välipuro (undrained) and Suopuro (drained), respectively. The results also suggest a greater near-surface throughflow component in Suopuro, the drained catchment, prior to snowmelt. CO(2) and DOC concentrations correlated positively with cation concentrations in both catchments indicating a common, peat/groundwater flowpath. CH(4) concentrations were significantly higher in the drained catchment and appeared to be transported in near-surface throughflow. Meltwater from the snowpack represented an important source of stream water CO(2) in both catchments, contributing up to 49% of total downstream CO(2) export during the study period. We conclude that the snowpack represents a potentially important, and often overlooked, transient carbon store in boreal snow-covered catchments. PMID:21885090

  1. Characterization of hydrologic inputs and streamflow pathways in headwater catchments of Boulder Creek Watershed, Colorado

    NASA Astrophysics Data System (ADS)

    Cowie, R. M.; Williams, M. W.; Mills, T. J.

    2012-12-01

    Streamflow pathways were investigated using isotopic and geochemical tracers in two gauged headwater catchments located at different elevations within the forested area of Boulder Creek Watershed, Colorado. Using diagnostic tools of mixing models indicates that both catchments fit reasonable well to a 1-D (two endmember) model for streamflow generation. End member mixing analysis (EMMA) suggests that streamflow at the lower elevation Gordon Gulch catchment (mean elevation 2627 m) was a combination of shallow subsurface flow and groundwater with limited influence from direct runoff. Steamflow at the higher elevation Como Creek catchment (mean elevation 3230 m) was a combination of runoff from snowmelt and groundwater. During the study period the total annual precipitation and the amount of precipitation falling as snow increased with elevation from 456 mm (41% snow) at Gordon Gulch to 804 mm (71% snow) at Como Creek. The resulting increase in winter snow accumulation at Como Creek demonstrates differences in timing and magnitude of hydrologic inputs between the two catchments and provides a potential driver for the differences in streamflow pathways. These results highlight the importance of understanding variations in streamflow pathways in relation to climatic variations across headwater mountain catchments. The broader impacts of streamflow pathway variations on steam nutrients will also be addressed.

  2. Streamflows at record highs

    NASA Astrophysics Data System (ADS)

    Streamflow was reported well above average in more than half the country during May, with flows at or near record levels for the month in 22 states, according to the U.S. Geological Survey (USGS), Department of the Interior.USGS hydrologists said that above average flow was reported at 98 of the 173 USGS key index gauging stations used in their monthly check on surface- and ground-water conditions. High flows were most prevalent in the Mississippi River basin states and in the east, with the exception of Maine, South Carolina, and Georgia. Below-average streamflow occurred in the Pacific northwest and in small scattered areas in Colorado, Kansas, Texas, and Minnesota.

  3. Seasonal streamflow forecasts in a semi-arid Andean watershed using remotely sensed snow cover data

    NASA Astrophysics Data System (ADS)

    Cartes, M.; McPhee, J.; Vargas, X.

    2009-04-01

    Forecasts of monthly streamflow during the snowmelt season are highly relevant for real-time decision making such as hydropower production scheduling, irrigation planning, and water transfers in market-driven water resource systems. The Chilean water bureau issues such forecasts, for a number of snowmelt-driven watersheds in northern and central Chile, based on measurements from a sparse network of snow course stations. This research aims at improving the accuracy of the government-issued seasonal forecasts by combining streamflow data and remotely sensed snow cover information through a recurrent neural network (RNN). The snow cover area (SCA) obtained from MODIS-Surface Reflectance product (MOD09) and the Normalized Differentiation Snow Index (NDSI), from 2000-2008 period, allow us to understand the variation of the snowmelt and accumulation processes in six different basins located in central Chile (32,5° - 34,5° south latitude; 69,5° -70,5° west longitude). For the three basins located at higher altitudes (> 1800 m.s.l.), after applying a cross-correlation procedure we determined a strong relation (r > 0.7) between SCA and the seasonal hydrograph, lagged around 4 months. The basin SCA, the NDSI at specific points inside the basin and past basin streamflow data are input to the RNN for recognizing the pattern variation of seasonal hydrograph through supervised learning. The determination coefficients for the validation period (r2 > 0.6) indicate a good support for the application of this methodology in normal-humid hydrological years. Particularly for the dryer years we obtain a considerable overestimation (around 30%) of the monthly snowmelt runoff. These results are limited by the availability of data for different types (dry, normal or humid) of hydrological years.

  4. Climate Change Impacts on Streamflow and Subbasin-Scale Hydrology in the Upper Colorado River Basin

    PubMed Central

    Ficklin, Darren L.; Stewart, Iris T.; Maurer, Edwin P.

    2013-01-01

    In the Upper Colorado River Basin (UCRB), the principal source of water in the southwestern U.S., demand exceeds supply in most years, and will likely continue to rise. While General Circulation Models (GCMs) project surface temperature warming by 3.5 to 5.6°C for the area, precipitation projections are variable, with no wetter or drier consensus. We assess the impacts of projected 21st century climatic changes on subbasins in the UCRB using the Soil and Water Assessment Tool, for all hydrologic components (snowmelt, evapotranspiration, surface runoff, subsurface runoff, and streamflow), and for 16 GCMs under the A2 emission scenario. Over the GCM ensemble, our simulations project median Spring streamflow declines of 36% by the end of the 21st century, with increases more likely at higher elevations, and an overall range of −100 to +68%. Additionally, our results indicated Summer streamflow declines with median decreases of 46%, and an overall range of −100 to +22%. Analysis of hydrologic components indicates large spatial and temporal changes throughout the UCRB, with large snowmelt declines and temporal shifts in most hydrologic components. Warmer temperatures increase average annual evapotranspiration by ∼23%, with shifting seasonal soil moisture availability driving these increases in late Winter and early Spring. For the high-elevation water-generating regions, modest precipitation decreases result in an even greater water yield decrease with less available snowmelt. Precipitation increases with modest warming do not translate into the same magnitude of water-yield increases due to slight decreases in snowmelt and increases in evapotranspiration. For these basins, whether modest warming is associated with precipitation decreases or increases, continued rising temperatures may make drier futures. Subsequently, many subbasins are projected to turn from semi-arid to arid conditions by the 2080 s. In conclusion, water availability in the UCRB could

  5. Parameter dimensionality reduction of a conceptual model for streamflow prediction in Canadian, snowmelt dominated ungauged basins

    NASA Astrophysics Data System (ADS)

    Arsenault, Richard; Poissant, Dominique; Brissette, François

    2015-11-01

    This paper evaluated the effects of parametric reduction of a hydrological model on five regionalization methods and 267 catchments in the province of Quebec, Canada. The Sobol' variance-based sensitivity analysis was used to rank the model parameters by their influence on the model results and sequential parameter fixing was performed. The reduction in parameter correlations improved parameter identifiability, however this improvement was found to be minimal and was not transposed in the regionalization mode. It was shown that 11 of the HSAMI models' 23 parameters could be fixed with little or no loss in regionalization skill. The main conclusions were that (1) the conceptual lumped models used in this study did not represent physical processes sufficiently well to warrant parameter reduction for physics-based regionalization methods for the Canadian basins examined and (2) catchment descriptors did not adequately represent the relevant hydrological processes, namely snow accumulation and melt.

  6. The Impact of Climate Change on Past and Future Streamflow at the Hubbard Brook Experimental Forest, New Hampshire, USA

    NASA Astrophysics Data System (ADS)

    Campbell, J. L.; Driscoll, C. T.; Pourmokhtarian, A.

    2009-12-01

    Long-term data from the Hubbard Brook Experimental Forest show that air temperature has increased by 1-1.5 °C over the last half century. While more variable, annual precipitation has also increased by 19-26% during the same period. These changes in climate influence streamflow, which provides an integrated climate signal that incorporates physical (snowpack, evaporation) and biological (evapotranspiration) responses. Unlike the western United States, water is generally abundant in the Northeast. However, changes in flow could nevertheless affect stream ecosystem services in the region, such as drinking water, irrigation, recreation, wastewater assimilation, and hydropower. We analyzed long-term data at the Hubbard Brook Experimental Forest to determine if past changes in climate have affected the distribution and quantity of streamflow. We also analyzed future changes in streamflow using the forest ecosystem model, PnET-BGC driven by climate input scenarios generated using downscaled AOGCM output. Past streamflow data indicate that the timing of streamflow has changed at Hubbard Brook. The winter/spring center of streamwater volume is occurring 0.18-0.25 days earlier each year, and streamflow increases during snowmelt have become less extreme over the 50 year record. Despite declines in snowmelt runoff, the number of high flow days per year has increased, due to increases in precipitation. Similarly, greater precipitation amounts have resulted in fewer low flow days. The overall amount of annual streamflow has increased significantly over the last 50 years, consistent with an increase in precipitation and no change in evapotranspiration. Future climate projections for Hubbard Brook show that air temperature and precipitation will continue to increase during the 21st century. Unlike historical data, preliminary PnET-BGC results indicate that projected increases in evapotranspiration will balance increases in precipitation, resulting in no significant change in

  7. Snowmelt hydrograph interpretation: Revealing watershed scale hydrologic characteristics of the Yellowstone volcanic plateau

    NASA Astrophysics Data System (ADS)

    Payton Gardner, W.; Susong, David D.; Kip Solomon, D.; Heasler, Henry

    2010-03-01

    SummarySnowmelt hydrograph analysis and groundwater age dates of cool water springs on the Yellowstone volcanic plateau provide evidence of high volumes of groundwater circulation in watersheds comprised of quaternary Yellowstone volcanics. Ratios of maximum to minimum mean daily discharge and average recession indices are calculated for watersheds within and surrounding the Yellowstone volcanic plateau. A model for snowmelt recession is used to separate groundwater discharge from overland runoff, and compare groundwater systems. Hydrograph signal interpretation is corroborated with chlorofluorocarbon (CFC) and tritium concentrations in cool water springs on the Yellowstone volcanic plateau. Hydrograph parameters show a spatial pattern correlated with watershed geology. Watersheds comprised dominantly of quaternary Yellowstone volcanics are characterized by slow streamflow recession, low maximum to minimum flow ratios. Cool springs sampled within the Park contain CFC's and tritium and have apparent CFC age dates that range from about 50 years to modern. Watersheds comprised of quaternary Yellowstone volcanics have a large volume of active groundwater circulation. A large, advecting groundwater field would be the dominant mechanism for mass and energy transport in the shallow crust of the Yellowstone volcanic plateau, and thus control the Yellowstone hydrothermal system.

  8. Snowmelt hydrograph interpretation: Revealing watershed scale hydrologic characteristics of the Yellowstone volcanic plateau

    USGS Publications Warehouse

    Payton, Gardner W.; Susong, D.D.; Kip, Solomon D.; Heasler, H.

    2010-01-01

    Snowmelt hydrograph analysis and groundwater age dates of cool water springs on the Yellowstone volcanic plateau provide evidence of high volumes of groundwater circulation in watersheds comprised of quaternary Yellowstone volcanics. Ratios of maximum to minimum mean daily discharge and average recession indices are calculated for watersheds within and surrounding the Yellowstone volcanic plateau. A model for snowmelt recession is used to separate groundwater discharge from overland runoff, and compare groundwater systems. Hydrograph signal interpretation is corroborated with chlorofluorocarbon (CFC) and tritium concentrations in cool water springs on the Yellowstone volcanic plateau. Hydrograph parameters show a spatial pattern correlated with watershed geology. Watersheds comprised dominantly of quaternary Yellowstone volcanics are characterized by slow streamflow recession, low maximum to minimum flow ratios. Cool springs sampled within the Park contain CFC's and tritium and have apparent CFC age dates that range from about 50 years to modern. Watersheds comprised of quaternary Yellowstone volcanics have a large volume of active groundwater circulation. A large, advecting groundwater field would be the dominant mechanism for mass and energy transport in the shallow crust of the Yellowstone volcanic plateau, and thus control the Yellowstone hydrothermal system. ?? 2009 Elsevier B.V.

  9. Effects of asynchronous snowmelt on flushing of dissolved organic carbon: A mixing model approach

    USGS Publications Warehouse

    Boyer, E.W.; Hornberger, G.M.; Bencala, K.E.; McKnight, Diane M.

    2000-01-01

    In many snowmelt-dominated catchments, stream dissolved organic carbon (DOC) levels typically increase rapidly as spring melt commences, peak before maximum discharge, and decrease quickly as melting continues. We present data from Deer Creek (Summit County, CO) that shows this distinctive flushing response of DOC during snowmelt runoff, with DOC stored in landscape soils flushed to the stream in response to infiltrating melt waters. Our prior studies show that asynchronous melting of the snowpack across the landscape causes the spring DOC flush to be initiated at different times throughout the catchment. In this study we quantify characteristics of the asynchronous melt and its effect on DOC flushing. We investigated whether a simple mixing model can be used to capture the essentials of the asynchronous melting of a seasonal snowpack and its controls on DOC transport. We divided the catchment into zones of aspect and elevation, which largely determine spatial and temporal variations in the distribution of snow. TOPMODEL was used to simulate the hydrology in each zone, and the simulated flow paths were routed through a simple DOC mixing model to predict contributions of DOC to the stream. The zonal responses were aggregated to give a predicted response of hydrology and DOC fluxes for the entire catchment. Our results indicate that asynchronous melting-which determines the timing of contributions of discharge and DOC to streamflow from different areas of the landscape-can be quantified using a simple modeling approach. Copyright ?? 2000 John Wiley & Sons, Ltd.

  10. Role of surface-water and groundwater interactions on projected summertime streamflow in snow dominated regions: An integrated modeling approach

    NASA Astrophysics Data System (ADS)

    Huntington, Justin L.; Niswonger, Richard G.

    2012-11-01

    Previous studies indicate predominantly increasing trends in precipitation across the Western United States, while at the same time, historical streamflow records indicate decreasing summertime streamflow and 25th percentile annual flows. These opposing trends could be viewed as paradoxical, given that several studies suggest that increased annual precipitation will equate to increased annual groundwater recharge, and therefore increased summertime flow. To gain insight on mechanisms behind these potential changes, we rely on a calibrated, integrated surface and groundwater model to simulate climate impacts on surface water/groundwater interactions using 12 general circulation model projections of temperature and precipitation from 2010 to 2100, and evaluate the interplay between snowmelt timing and other hydrologic variables, including streamflow, groundwater recharge, storage, groundwater discharge, and evapotranspiration. Hydrologic simulations show that the timing of peak groundwater discharge to the stream is inversely correlated to snowmelt runoff and groundwater recharge due to the bank storage effect and reversal of hydraulic gradients between the stream and underlying groundwater. That is, groundwater flow to streams peaks following the decrease in stream depth caused by snowmelt recession, and the shift in snowmelt causes a corresponding shift in groundwater discharge to streams. Our results show that groundwater discharge to streams is depleted during the summer due to earlier drainage of shallow aquifers adjacent to streams even if projected annual precipitation and groundwater recharge increases. These projected changes in surface water/groundwater interactions result in more than a 30% decrease in the projected ensemble summertime streamflow. Our findings clarify causality of observed decreasing summertime flow, highlight important aspects of potential climate change impacts on groundwater resources, and underscore the need for integrated hydrologic

  11. Effects of reservoir installation, San Juan-Chama Project water, and reservoir operations on streamflow and water quality in the Rio Chama and Rio Grande, northern and central New Mexico, 1938-2000

    USGS Publications Warehouse

    Langman, Jeff B.; Anderholm, Scott K.

    2004-01-01

    The coordinated operation of Heron, El Vado, and Abiquiu Dams on the Rio Chama and Cochiti Dam on the Rio Grande and the importation of Colorado River Basin water by the San Juan-Chama Project have altered streamflow and water quality of the Rio Chama and Rio Grande in northern and central New Mexico. The coordinated retention of streamflow in the four reservoirs increased median streamflows, decreased extreme flows, and decreased periods of small streamflow; inflow of San Juan-Chama Project water increased overall streamflow in the Rio Chama and Rio Grande. These changes to streamflow decreased specific conductance and suspended-sediment concentration and increased pH in the Rio Chama and the Rio Grande. Following construction of Heron and Cochiti Dams and integration of reservoir operations on the Rio Chama and the Rio Grande, the inflow of San Juan-Chama Project water and retention of snowmelt runoff influenced water quality. These influences varied by season because reservoir releases fluctuated according to downstream user needs and annual streamflow variation. The influences of San Juan-Chama Project water and retained snowmelt on water quality diminished with downstream flow as the Rio Grande was subjected to various natural and anthropogenic inflows. Because of the variability and type of seasonal influences, streamflow did not have a strong annual correlation with water quality in the Rio Chama or the Rio Grande.

  12. Post-settlement drivers of streamflow variability in the Canadian Prairies: an analysis of the effects of the Anthropocene

    NASA Astrophysics Data System (ADS)

    Nazemi, A.; Wheater, H. S.; Chun, K. P.; Bonsal, B. R.

    2014-12-01

    The Canadian Prairies are home to 75% of Canada's irrigated agriculture. This is supported by the historically reliable streamflow regime in the South Saskatchewan River (SSR), which is initiated from snowmelt on the eastern slopes of the Rocky Mountains. This streamflow regime, however, is facing various changes. Most obviously, post-settlement water resource management in the prairies has intensively regulated the timing and volume of natural streamflows. Moreover, the natural streamflow regime in the SSR exhibits large inter-annual variability, influenced by the phases of Pacific Decadal Oscillation (PDO). Finally, some other sources of climate variability have recently resulted in significant shifts in the timing and volume of the regional streamflow, associated with changes in the form and timing of precipitation as well as variations in annual snow accumulation and melt in headwater catchments. By considering five unregulated and three regulated streams, we formally diagnose the post-settlement drivers of variability in the SSR's streamflow regime using various statistical tests. Our results show that long-term variations in the SSR streamflow timing and volume can be described by complex interactions among the PDO, human regulation and non-PDO sources of climate variability. For instance, human regulation can intensify the variations in annual streamflow volume during extreme PDO conditions, and non-PDO sources of climate variability can be masked by the effects of PDO and/or human regulation. Changes in the annual streamflow timing can be linked to human regulation and non-PDO sources of climate variability; in particular, human regulation is the main driver of recent dependence between annual streamflow timing and volume. Our findings have major importance for water security assessment in the Canadian Prairies and contribute to better understanding of feedbacks in coupled Natural-Human water systems during the current Anthropocene.

  13. Understanding the Role of Controls on the Timing of Daily Streamflow Peak and its Seasonal Variation

    NASA Astrophysics Data System (ADS)

    Chen, X.; Kumar, M.; Wang, R.; Winstral, A. H.; Marks, D. G.

    2014-12-01

    Understanding and prediction of snowmelt generated streamflow at sub-daily time scales is important for reservoir scheduling and climate change characterization. This is particularly important in the Western U.S. where over 50 - 70% of water supply is provided by snowmelt during the melting period. Previous studies reported that daily peak flow timing might shift earlier in some basins, but later in others during the melt season. This shift of peak flow timing was attributed to three crucial processes: translation time of liquid water flux through snowpack, translation time from the base of snowpacks to river channels, and translation time in the river channels to stream gage stations. Here we evaluate our ability to simulate the sub-daily streamflow peak time and quantitatively explore the relative contribution from each individual factor. Our analysis shows that the timing of the daily peak is dominantly controlled by melt translation time from the bottom of snowpack to the river channel, while the seasonal variation in daily peak is influenced the most by translation time through the snow pack. An additional factor, the increasing trend of temperature and radiation in melt season, is also contributing to the timing of peak streamflow and its variations.

  14. Sensitivity of Alpine Snow and Streamflow Regimes to Climate Changes

    NASA Astrophysics Data System (ADS)

    Rasouli, K.; Pomeroy, J. W.; Marks, D. G.; Bernhardt, M.

    2014-12-01

    Understanding the sensitivity of hydrological processes to climate change in alpine areas with snow dominated regimes is of paramount importance as alpine basins show both high runoff efficiency associated with the melt of the seasonal snowpack and great sensitivity of snow processes to temperature change. In this study, meteorological data measured in a selection of alpine headwaters basins including Reynolds Mountain East, Idaho, USA, Wolf Creek, Yukon in Canada, and Zugspitze Mountain, Germany with climates ranging from arctic to continental temperate were used to study the snow and streamflow sensitivity to climate change. All research sites have detailed multi-decadal meteorological and snow measurements. The Cold Regions Hydrological Modelling platform (CRHM) was used to create a model representing a typical alpine headwater basin discretized into hydrological response units with physically based representations of snow redistribution by wind, complex terrain snowmelt energetics and runoff processes in alpine tundra. The sensitivity of snow hydrology to climate change was investigated by changing air temperature and precipitation using weather generating methods based on the change factors obtained from different climate model projections for future and current periods. The basin mean and spatial variability of peak snow water equivalent, sublimation loss, duration of snow season, snowmelt rates, streamflow peak, and basin discharge were assessed under varying climate scenarios and the most sensitive hydrological mechanisms to the changes in the different alpine climates were detected. The results show that snow hydrology in colder alpine climates is more resilient to warming than that in warmer climates, but that compensatory factors to warming such as reduced blowing snow sublimation loss and reduced melt rate should also be assessed when considering climate change impacts on alpine hydrology.

  15. Spatio-temporal variability of snowmelt and runoff generation during rain-on-snow events in a forested mountain environment

    NASA Astrophysics Data System (ADS)

    Garvelmann, Jakob; Pohl, Stefan; Weiler, Markus

    2014-05-01

    A network consisting of 81 standalone snow monitoring stations (SnoMoS), precipitation measurements, and streamflow data was used to analyze the observed snowcover distribution and melt dynamics during mid-winter rain-on-snow (ROS) events generating flooding in three study catchments with differing elevations, topographic characteristics, and areal extent in the Black Forest region of south-western Germany. The crucial importance of the initial snowcover distribution prior to the event became evident. The contribution of snowmelt to total runoff was on average about 60%, highlighting the significance of snowmelt for the flood generation during ROS. The catchment with the most distinct topography was selected to further investigate the drivers of the spatio-temporal variability of snowmelt and the water available for stormflow runoff. A multiple linear regression analysis using elevation, aspect, and land cover as predictors for the SWE distribution within the catchment was applied on an hourly time-step using the observed dynamic at the SnoMoS locations. Based on this analysis the spatial distribution of the initial snowcover and the snowmelt occurring in different parts of the study basin during two ROS events in December 2012 was calculated. The amount and the spatial distribution of water potentially being available for the generation of runoff at the interface between the snowpack and the surface below was calculated considering spatially variable melt rates, water retention capacity of the snow cover and the input of liquid precipitation. Elevation was found to be the most important terrain feature having the biggest influence on the water release from the snowpack. Even though the highest total amounts of water from precipitation and snowmelt were potentially available for runoff in the higher elevations, the snowpack released reduced amounts of water to runoff in these regions. South-facing terrain contributed more to runoff than north facing slopes and more

  16. Has global warming changed timing of winter-spring streamflows over North America?

    NASA Astrophysics Data System (ADS)

    Kam, J.; Knutson, T. R.; Milly, P. C. D.

    2015-12-01

    Wherever snowmelt runoff substantially contributes to winter-spring streamflows, warmer winter-spring temperature can accelerate snow melt and reduce later streamflows. These changes can adversely affect human activities and ecological communities (e.g. flood, drought, salmon survival rate, and blooming season). Here we investigate changes in timing of winter-spring streamflows over North America (NA) during 1933-2013 and 1951-2000 using observed streamflow and simulated runoff from pre-industrial (unforced) control and historical (realistically forced) runs from the Geophysical Fluid Dynamics Laboratory Climate Model version 3. The study regions are north of 41˚N in NA. We analyze winter-spring center of volume date (WSCV), the date by which half of the accumulated January through June daily streamflow volume occurs. We first performed a sliding trend analysis of WSCV for time periods starting in various years (1951 through 1984) and ending in 2000. We found that the observed decreasing trends (Theil-Sen slopes) of WSCV over the northeast and northwest U.S. regions are at the edge of detectability (i.e., lie near the edge of the 5th-95th percentile envelope of control runs) for trends beginning any time between 1950 and 1970, but are consistent with the envelope of historical runs for all beginning trend years. Interestingly, for the 1933-2013 analysis, results for the northwest U.S. show that the observed trends of WSCV are positive for periods beginning as early as the mid-1960s, and inconsistent with historical runs for periods beginning in the mid-1950s and later. Aside from this inconsistency, observed trends to 2013 are consistent with both control and historical runs. This study suggests that internal variability has played a major role in timing of winter-spring streamflows to date, despite global warming, and thus that clear detection and attribution of WSCV trends in the study regions may require longer streamflow records than those now available.

  17. Recent tree die-off has little effect on streamflow in contrast to expected increases from historical studies

    NASA Astrophysics Data System (ADS)

    Biederman, Joel A.; Somor, Andrew J.; Harpold, Adrian A.; Gutmann, Ethan D.; Breshears, David D.; Troch, Peter A.; Gochis, David J.; Scott, Russell L.; Meddens, Arjan J. H.; Brooks, Paul D.

    2015-12-01

    Recent bark beetle epidemics have caused regional-scale tree mortality in many snowmelt-dominated headwater catchments of western North America. Initial expectations of increased streamflow have not been supported by observations, and the basin-scale response of annual streamflow is largely unknown. Here we quantified annual streamflow responses during the decade following tree die-off in eight infested catchments in the Colorado River headwaters and one nearby control catchment. We employed three alternative empirical methods: (i) double-mass comparison between impacted and control catchments, (ii) runoff ratio comparison before and after die-off, and (iii) time-trend analysis using climate-driven linear models. In contrast to streamflow increases predicted by historical paired catchment studies and recent modeling, we did not detect streamflow changes in most basins following die-off, while one basin consistently showed decreased streamflow. The three analysis methods produced generally consistent results, with time-trend analysis showing precipitation was the strongest predictor of streamflow variability (R2 = 74-96%). Time-trend analysis revealed post-die-off streamflow decreased in three catchments by 11-29%, with no change in the other five catchments. Although counter to initial expectations, these results are consistent with increased transpiration by surviving vegetation and the growing body of literature documenting increased snow sublimation and evaporation from the subcanopy following die-off in water-limited, snow-dominated forests. The observations presented here challenge the widespread expectation that streamflow will increase following beetle-induced forest die-off and highlight the need to better understand the processes driving hydrologic response to forest disturbance.

  18. Potential impacts of climate warming on runoff from snowmelt: a case study of two mountainous basins in the Upper Rio Grande

    NASA Astrophysics Data System (ADS)

    Rango, A.; Steele, C. M.; Elias, E.; Mejia, J.; Fernald, A.

    2013-12-01

    We used historical climate, snow cover and streamflow data in the Snowmelt Runoff Model (SRM) to drive simulations of runoff from two mountainous basins in the Upper Rio Grande. The basins selected for this study are El Rito and Santa Fe. With climate warming, both have been shown to be at risk of losing annual snowpack and the associated peak in the spring hydrograph caused by snowmelt. Historical flow simulations supplied model parameters specific to each basin (runoff coefficients, degree day factors, temperature lapse rates, critical temperature and recession coefficients). These parameters were then used in applying SRM under changed climate conditions (scenario A2, ECHAM-5 general circulation model, 2046-2100). Although there is some interannual variability, under the A2 scenario the SRM simulations imply (i) a profound loss of annual snowpack at all but the highest elevations; (ii) decline in springtime streamflow (fraction of flow occurring between April and July) and (iii) earlier occurrence of winter-spring center of volume (half total runoff volume for January 1 to May 31). Our results have profound implications for the rural acequia community in El Rito for whom the annual snowpack acts as a natural reservoir releasing water to the acequias (irrigation canals) concurrent with the beginning of the growing season. In El Rito, the only alternative to water from snowmelt runoff is groundwater, but this source of water will also be affected by the accumulation, quantity and duration of annual snowpack. With two reservoirs, the urban area of Santa Fe is less dependent on the timing of snowmelt than El Rito. Additionally, Santa Fe has access to alternate sources of surface water (e.g., from the San Juan-Chama Project). Nevertheless, climate-change induced scarcity of water throughout the region will also have important socio-economic and political impacts on the City of Santa Fe.

  19. Blending satellite-based snow depth products with in situ observations for streamflow predictions in the Upper Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Liu, Yuqiong; Peters-Lidard, Christa D.; Kumar, Sujay V.; Arsenault, Kristi R.; Mocko, David M.

    2015-02-01

    In snowmelt-driven river systems, it is critical to enable reliable predictions of the spatiotemporal variability in seasonal snowpack to support local and regional water management. Previous studies have shown that assimilating satellite-station blended snow depth data sets can lead to improved snow predictions, which however do not always translate into improved streamflow predictions, especially in complex mountain regions. In this study, we explore how an existing optimal interpolation-based blending strategy can be enhanced to reduce biases in satellite snow depth products for improving streamflow predictions. Two major new considerations are explored, including: (1) incorporating terrain aspect and (2) incorporating areal snow coverage information. The methodology is applied to the bias reduction of the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E) snow depth estimates, which are then assimilated into the Noah land surface model via the ensemble Kalman Filtering (EnKF) for streamflow predictions in the Upper Colorado River Basin. Our results indicate that using only observations from low-elevation stations such as the Global Historical Climatology Network (GHCN) in the bias correction can lead to underestimation in streamflow, while using observations from high-elevation stations (e.g., the Snow Telemetry (SNOTEL) network) along with terrain aspect is critically important for achieving reliable streamflow predictions. Additionally incorporating areal snow coverage information from the Moderate Resolution Imaging Spectroradiometer (MODIS) can slightly improve the streamflow results further.

  20. Large snowmelt versus rainfall events in the mountains

    NASA Astrophysics Data System (ADS)

    Fassnacht, Steven R.; Records, Rosemary M.

    2015-03-01

    While snow is the dominant precipitation type in mountain regions, estimates of rainfall are used for design, even though snowmelt provides most of the runoff. Daily data were used to estimate the 10 and 100 year, 24 h snowmelt, precipitation, and rainfall events at 90 Snow Telemetry stations across the Southern Rocky Mountains. Three probability distributions were compared, and the Pearson type III distribution yielded the most conservative estimates. Precipitation was on average 33% and 28% more than rainfall for the 10 and 100 year events. Snowfall exceeded rainfall at most of the stations and was on average 53% and 38% more for the 10 and 100 year events. On average, snowmelt was 15% and 8.9% more than precipitation. Where snow accumulation is substantial, it is recommended that snowmelt be considered in conjunction with rainfall and precipitation frequencies to develop flood frequencies.

  1. Evaluation of Snow Cover Depletion to Support Snowmelt Runoff Prediction for the Cache la Poudre River, Colorado

    NASA Astrophysics Data System (ADS)

    Richer, E. E.; Kampf, S. K.; Fassnacht, S. R.

    2008-12-01

    The Cache la Poudre River in northeastern Colorado is a source of water for many agricultural, municipal, and industrial users. Most runoff in the basin is generated from snowmelt, but snow measurements are sparse, located only at a few high elevation SNOTEL stations and snow courses. Over much of the watershed, no snow measurements are available to support runoff forecasts. For this study we analyzed snow covered area (SCA) depletion characteristics to evaluate whether SCA data could improve snowmelt runoff prediction. Moderate Resolution Imaging Spectroradiometer (MODIS) 8-day snow-cover products were obtained for the Cache la Poudre basin from 2000 to 2006 for March through June of each year. We analyzed snow cover depletion characteristics for spatial subsets of the basin, including sub-basins and elevation bands. Regression analyses compare the 8-day SCA images to 8-day average stream flow at the USGS canyon mouth gauge (the forecasting location). Results from regression analyses show a wide range of relationships between SCA and streamflow (0.032<0.92), mostly as a result of high inter- annual variability in the flow regime. SCA image impairment from cloud cover was generally low but did impact results in some years. For sub-basins, the strongest correlations between SCA and streamflow were for high elevation sub-basins (0.602<0.92), whereas for elevation bands, the strongest correlations were for a mid-elevation band, 2680-3042 m (0.602<0.92). The poorest relationships between SCA and streamflow occurred for low elevation bands, 1591-1953 m and 1954-2315 m, and very high elevation bands, 3406-3768 m and 3769-4131 m. The strong relationship between SCA and discharge at middle elevations suggests that runoff prediction can be improved by monitoring snow cover within these areas. The initial rise in the snowmelt hydrograph correlates well with SCA depletion at middle elevations, whereas the onset of peak flow does not occur until a significant change in snow

  2. Winter streamflow analysis in frozen, alpine catchments to quantify groundwater contribution and properties

    NASA Astrophysics Data System (ADS)

    Stoelzle, Michael; Weiler, Markus

    2016-04-01

    Alpine catchments are often considered as quickly responding systems where streamflow contributions from subsurface storages (groundwater) are mostly negligible due to the steep topography, low permeable bedrock and the absence of well-developed soils. Many studies in high altitude catchments have hence focused on water stored in snowpack and glaciers or on rainfall-runoff processes as the dominant streamflow contributions. Interestingly less effort has been devoted to winter streamflow analysis when melt- or rainfall-driven contributions are switched off due to the frozen state of the catchment. Considering projected changes in the alpine cryosphere (e.g. snow, glacier, permafrost) quantification of groundwater storage and contribution to streamflow is crucial to assess the social and ecological implications for downstream areas (e.g. water temperature, drought propagation). In this study we hypothesize that groundwater is the main streamflow contribution during winter and thus being responsible for the perennial regime of many alpine catchments. The hypothesis is investigated with well-known methods based on recession and breakpoint analysis of the streamflow regimes and temperature data to determine frozen periods. Analyzing nine catchments in Switzerland with mean elevation between 1000 and 2400 m asl, we found that above a mean elevation of 1800 m asl winter recessions are sufficient long and persistent enough to quantify groundwater contribution to streamflow and to characterize the properties of subsurface storage. The results show that groundwater in alpine catchment is the dominant streamflow contribution for nearly half a year and accountable for several hundred millimeter of annual streamflow. In sub-alpine catchments, driven by a mix of snowmelt and rainfall, a clear quantification of groundwater contributions is rather challenging due to discontinuous frozen periods in winter. We found that the inter-annual variability of different streamflow

  3. Effect of reforestation on streamflow in central New York

    USGS Publications Warehouse

    Schneider, William Joseph; Ayer, Gordon Roundy

    1961-01-01

    interception and transpiration in the reforested areas. The reductions in peak discharges during the dormant period are attributed largely to increased interception and sublimation of snowfall, and a gradual desynchronization of snowmelt runoff from the wooded and open areas of partly reforested watersheds. The changes in streamflow occurred gradually over the years; it could not be determined from the data whether changes in streamflow were still occurring in 1958, or whether they had reached a maximum.

  4. A new method of snowmelt sampling for water stable isotopes

    USGS Publications Warehouse

    Penna, D.; Ahmad, M.; Birks, S. J.; Bouchaou, L.; Brencic, M.; Butt, S.; Holko, L.; Jeelani, G.; Martinez, D. E.; Melikadze, G.; Shanley, J.B.; Sokratov, S. A.; Stadnyk, T.; Sugimoto, A.; Vreca, P.

    2014-01-01

    We modified a passive capillary sampler (PCS) to collect snowmelt water for isotopic analysis. Past applications of PCSs have been to sample soil water, but the novel aspect of this study was the placement of the PCSs at the ground-snowpack interface to collect snowmelt. We deployed arrays of PCSs at 11 sites in ten partner countries on five continents representing a range of climate and snow cover worldwide. The PCS reliably collected snowmelt at all sites and caused negligible evaporative fractionation effects in the samples. PCS is low-cost, easy to install, and collects a representative integrated snowmelt sample throughout the melt season or at the melt event scale. Unlike snow cores, the PCS collects the water that would actually infiltrate the soil; thus, its isotopic composition is appropriate to use for tracing snowmelt water through the hydrologic cycle. The purpose of this Briefing is to show the potential advantages of PCSs and recommend guidelines for constructing and installing them based on our preliminary results from two snowmelt seasons.

  5. Snowmelt runoff: a new focus of urban nonpoint source pollution.

    PubMed

    Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

    2012-12-01

    Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing constitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control. PMID:23202881

  6. Snowmelt Runoff: A New Focus of Urban Nonpoint Source Pollution

    PubMed Central

    Zhu, Hui; Xu, Yingying; Yan, Baixing; Guan, Jiunian

    2012-01-01

    Irregular precipitation associated with global climate change had been causing various problems in urban regions. Besides the runoff due to rainfall in summer, the snowmelt runoff in early spring could also play an important role in deteriorating the water quality of the receiving waters. Due to global climate change, the snowfall has increased gradually in individual regions, and snowstorms occur more frequently, which leads to an enhancement of snowmelt runoff flow during the melting seasons. What is more, rivers just awaking from freezing cosntitute a frail ecosystem, with poor self-purification capacity, however, the urban snowmelt runoff could carry diverse pollutants accumulated during the winter, such as coal and/or gas combustion products, snowmelting agents, automotive exhaust and so on, which seriously threaten the receiving water quality. Nevertheless, most of the research focused on the rainfall runoff in rainy seasons, and the study on snowmelt runoff is still a neglected field in many countries and regions. In conclusion, due to the considerable water quantity and the worrisome water quality, snowmelt runoff in urban regions with large impervious surface areas should be listed among the important targets in urban nonpoint source pollution management and control. PMID:23202881

  7. Streamflow changes in the Sierra Nevada, California, simulated using a statistically downscaled general circulation model scenario of climate change

    USGS Publications Warehouse

    Wilby, Robert L.; Dettinger, Michael D.

    2000-01-01

    Simulations of future climate using general circulation models (GCMs) suggest that rising concentrations of greenhouse gases may have significant consequences for the global climate. Of less certainty is the extent to which regional scale (i.e., sub-GCM grid) environmental processes will be affected. In this chapter, a range of downscaling techniques are critiqued. Then a relatively simple (yet robust) statistical downscaling technique and its use in the modelling of future runoff scenarios for three river basins in the Sierra Nevada, California, is described. This region was selected because GCM experiments driven by combined greenhouse-gas and sulphate-aerosol forcings consistently show major changes in the hydro-climate of the southwest United States by the end of the 21st century. The regression-based downscaling method was used to simulate daily rainfall and temperature series for streamflow modelling in three Californian river basins under current-and future-climate conditions. The downscaling involved just three predictor variables (specific humidity, zonal velocity component of airflow, and 500 hPa geopotential heights) supplied by the U.K. Meteorological Office couple ocean-atmosphere model (HadCM2) for the grid point nearest the target basins. When evaluated using independent data, the model showed reasonable skill at reproducing observed area-average precipitation, temperature, and concomitant streamflow variations. Overall, the downscaled data resulted in slight underestimates of mean annual streamflow due to underestimates of precipitation in spring and positive temperature biases in winter. Differences in the skill of simulated streamflows amongst the three basins were attributed to the smoothing effects of snowpack on streamflow responses to climate forcing. The Merced and American River basins drain the western, windward slope of the Sierra Nevada and are snowmelt dominated, whereas the Carson River drains the eastern, leeward slope and is a mix of

  8. A spatially distributed energy balance snowmelt model for application in mountain basins

    USGS Publications Warehouse

    Marks, D.; Domingo, J.; Susong, D.; Link, T.; Garen, D.

    1999-01-01

    Snowmelt is the principal source for soil moisture, ground-water re-charge, and stream-flow in mountainous regions of the western US, Canada, and other similar regions of the world. Information on the timing, magnitude, and contributing area of melt under variable or changing climate conditions is required for successful water and resource management. A coupled energy and mass-balance model ISNOBAL is used to simulate the development and melting of the seasonal snowcover in several mountain basins in California, Idaho, and Utah. Simulations are done over basins varying from 1 to 2500 km2, with simulation periods varying from a few days for the smallest basin, Emerald Lake watershed in California, to multiple snow seasons for the Park City area in Utah. The model is driven by topographically corrected estimates of radiation, temperature, humidity, wind, and precipitation. Simulation results in all basins closely match independently measured snow water equivalent, snow depth, or runoff during both the development and depletion of the snowcover. Spatially distributed estimates of snow deposition and melt allow us to better understand the interaction between topographic structure, climate, and moisture availability in mountain basins of the western US. Application of topographically distributed models such as this will lead to improved water resource and watershed management.Snowmelt is the principal source for soil moisture, ground-water re-charge, and stream-flow in mountainous regions of the western US, Canada, and other similar regions of the world. Information on the timing, magnitude, and contributing area of melt under variable or changing climate conditions is required for successful water and resource management. A coupled energy and mass-balance model ISNOBAL is used to simulate the development and melting of the seasonal snowcover in several mountain basins in California, Idaho, and Utah. Simulations are done over basins varying from 1 to 2500 km2, with

  9. Potential effects of climate change on streamflow, eastern and western slopes of the Sierra Nevada, California and Nevada

    USGS Publications Warehouse

    Jeton, A.E.; Dettinger, M.D.; Smith, Jody L.

    1996-01-01

    Precipitation-runoff models of the East Fork Carson and North Fork American Rivers were developed and calibrated for use in evaluating the sensitivity of streamflow in the north-central Sierra Nevada to climate change. The East Fork Carson River drains part of the rain-shadowed, eastern slope of the Sierra Nevada and is generally higher than the North Fork American River, which drains the wetter, western slope. First, a geographic information system was developed to describe the spatial variability of basin characteristics and to help estimate model parameters. The result was a partitioning of each basin into noncontiguous, but hydrologically uniform, land units. Hydrologic descriptions of these units were developed and the Precipitation- Runoff Modeling System (PRMS) was used to simulate water and energy balances for each unit in response to daily weather conditions. The models were calibrated and verified using historical streamflows over 22-year (Carson River) and 42-year (American River) periods. Simulated annual streamflow errors average plus 10 percent of the observed flow for the East Fork Carson River basin and plus 15 percent for the North Fork American River basin. Interannual variability is well simulated overall, but, at daily scales, wet periods are simulated more accurately than drier periods. The simulated water budgets for the two basins are significantly different in seasonality of streamflow, sublimation, evapotranspiration, and snowmelt. The simulations indicate that differences in snowpack and snowmelt timing can play pervasive roles in determining the sensitivity of water resources to climate change, in terms of both resource availability and amount. The calibrated models were driven by more than 25 hypothetical climate-change scenarios, each 100 years long. The scenarios were synthesized and spatially disaggregated by methods designed to preserve realistic daily, monthly, annual, and spatial statistics. Simulated streamflow timing was not very

  10. Recent bark beetle outbreaks have little impact on streamflow in the Western United States

    NASA Astrophysics Data System (ADS)

    Slinski, Kimberly M.; Hogue, Terri S.; Porter, Aaron T.; McCray, John E.

    2016-07-01

    In the Western United States (US), the current mountain pine beetle (MPB; Dendroctonus ponderosae) epidemic has affected more than five million hectares since its start in 1996, including headwater catchments that supply water to much of the Western US. There is widespread concern that the hydrologic consequences of the extensive pine tree die-off will impact water supply across the Western US. While forest disturbance studies have shown that streamflow increases in response to tree harvest, the actual effect of bark beetle infestations on water supply remains widely debated. The current study evaluates watershed-level response following bark beetle outbreak for 33 watersheds in seven western states. Streamflow records were investigated to assess whether the timing and amount of stream discharge during bark beetle outbreak and early recovery periods were significantly different to pre-outbreak conditions. Results show no significant modification in peak flows or average daily streamflow following bark beetle infestation, and that climate variability may be a stronger driver of streamflow patterns and snowmelt timing than chronic forest disturbance.

  11. Impacts of Forecasted Climate Change on Snowpack, Glacier Recession, and Streamflow in the Nooksack River Basin

    NASA Astrophysics Data System (ADS)

    Murphy, R. D.; Mitchell, R. J.; Bandaragoda, C.; Grah, O. J.

    2015-12-01

    Like many watersheds in the North Cascades Mountain range, streamflow in the Nooksack River is strongly influenced by precipitation and snowmelt in the spring and glacial melt in the warmer summer months. With a maritime climate and a high relief basin with glacial ice (3400 hectares), the streamflow response in the Nooksack is sensitive to increases in temperature, thus forecasting the basins response to future climate is of vital importance for water resources planning purposes. The watershed (2000 km2) in the northwest of Washington, USA, is a valuable freshwater resource for regional municipalities, industry, and agriculture, and provides critical habitat for endangered salmon species. Due to a lack of spatially distributed long-term historical weather observations in the basin for downscaling purposes, we apply publically available statistically derived 1/16 degree gridded surface data along with the Distributed Hydrology Soil Vegetation Model (DHSVM; Wigmosta et al., 1992) with newly developed coupled dynamic glacier model (Clarke et al., 2015) to simulate hydrologic processes in the Nooksack River basin. We calibrate and validate the DHSVM to observed glacial mass balance and glacial ice extent as well as to observed daily streamflow and SNOTEL data in the Nooksack basin. For the historical period, we model using a gridded meteorological forcing data set (1950-2010; Livneh et al., 2013). We simulate forecasted climate change impacts, including glacial recession on streamflow, using gridded daily statically downscaled data from global climate models of the CMIP5 with RCP4.5 and RCP8.5 forcing scenarios developed using the multivariate adaptive constructed analogs method (Abatzoglou and Brown, 2011). Simulation results project an increase in winter streamflows due to more rainfall rather than snow, and a decrease in summer flows with a general shift in peak spring flows toward earlier in the spring. Glacier melt contribution to streamflow initially increases

  12. The role of snowmelt and glacier melt on runoff in a glacierized catchment: a multi-tracer experiment

    NASA Astrophysics Data System (ADS)

    Penna, Daniele; Engel, Michael; Mao, Luca; Dell'Agnese, Andrea; Bertoldi, Giacomo; Comiti, Francesco

    2013-04-01

    The release of water as snowmelt and ice melt in high elevation catchments has significant social and economic impacts for population living in mountain areas. This is even more critical under the current conditions of glacier retreat as a consequence of global warming. Therefore, it is important to understand the role of ice and snow meltwater on runoff dynamics and groundwater recharge in glacierized environments. This task can be effectively accomplished by integrating isotopic and other tracers that are widely recognized as useful tools for the identification of the main water sources contributing to streamflow. In this work, we collected water samples from different sources in the Saldur catchment (Eastern Italian Alps). The catchment (area: 62 km², elevation range: 1600-3700 m a.s.l.) hosts a small glacier (2.8 km²) in its upper portion. Samples of rainfall, snow, snowmelt, glacier melt, stream water (main stream and tributaries) and spring water have been manually collected between April-October 2011 and April-November 2012 approximately on a monthly basis. Furthermore, 24-hour samplings with hourly collection frequency were performed at two cross sections during five melt-runoff events. The composition in stable water isotopes was determined by laser spectroscopy and mass spectrometry. Electrical conductivity (EC) and water temperature were measured in the field. Additionally, deuterium excess (DE) was computed for all samples based on the relationship between deuterium and 18-oxygen. The isotopic composition of rainfall and snow shows marked altitudinal and seasonal variations. A strong positive correlation is also evident in the relationship between DE of spring waters and elevation. Rainfall and snow samples fall perfectly on the Global Meteoric Water Line, revealing a predominant Atlantic origin of air masses producing precipitation in the study area. EC and water temperature linearly increase with the distance from the glacier snout, suggesting a

  13. Attribution of high resolution streamflow trends in Western Austria - an approach based on climate and discharge station data

    NASA Astrophysics Data System (ADS)

    Kormann, C.; Francke, T.; Renner, M.; Bronstert, A.

    2015-03-01

    streamflow changes are increased glacial melt, earlier snowmelt and lower snow accumulation in wintertime.

  14. Pathways of Snowmelt Water into an Ice-Covered Lake

    NASA Astrophysics Data System (ADS)

    Cortes, A.; MacIntyre, S.; Sadro, S.

    2015-12-01

    Discharge of water into ice-covered arctic lakes during snowmelt can be high, but no general framework exists to quantify the pathway of the flow into the lakes and the associated distribution of incoming resources including dissolved organic carbon (DOC) or greenhouse gases. In this study, we characterize the fate of the snowmelt water flowing into 1.5 km2 Toolik Lake, Alaska, in 2014 and 2015. We deployed arrays with temperature, conductivity, and oxygen sensors in the water column over the winter, performed high temporal and spatial resolution CTD surveys on four 500 m to 1 km long transect lines during spring, and obtained correlative meteorological and discharge data. During both study spring periods, we observed different snowmelt inflow regimes based on the discharge rate (low and high) which led to differences in the extent of vertical and horizontal dilution of the lake water. Our first estimates of horizontal dispersion of snowmelt water in Toolik Lake under a high discharge regime are in the upper range of values found for ice-covered lakes (O ~ (102) cm2 s-1). In both years, the incoming water spread over ~75% of the basin near the surface with associated loading of DOC and methane. Spring 2014 was typical of other years with a gradual snowmelt and restricted depth of penetration of the incoming water. In fact, the increased density gradient in the upper few meters created conditions which retarded subsequent mixing at ice off. In contrast, persistent high pressures over the Alaskan region caused an exceptionally warm spring and rapid snowmelt in 2015. The subsequent warming of stream waters meant that the within lake vertical density gradient was weakened and facilitated later mixing. The differences in magnitude of discharge and temperature of incoming water during the more average and the warm springs enable interpretations and predictions of the fate of solutes flowing into lakes during snowmelt under variable weather regimes.

  15. Role of climate forecasts and initial conditions in developing streamflow and soil moisture forecasts in a rainfall-runoff regime

    NASA Astrophysics Data System (ADS)

    Sinha, T.; Sankarasubramanian, A.

    2013-02-01

    Skillful seasonal streamflow forecasts obtained from climate and land surface conditions could significantly improve water and energy management. Since climate forecasts are updated on a monthly basis, we evaluate the potential in developing operational monthly streamflow forecasts on a continuous basis throughout the year. Further, basins in the rainfall-runoff regime critically depend on the forecasted precipitation in the upcoming months as opposed to snowmelt regimes where initial hydrological conditions (IHC) play a critical role. The goal of this study is to quantify the role of updated monthly precipitation forecasts and IHC in forecasting 6-month lead monthly streamflow and soil moisture for a rainfall-runoff mechanism dominated basin - Apalachicola River at Chattahoochee, FL. The Variable Infiltration Capacity (VIC) land surface model is implemented with two forcings: (a) updated monthly precipitation forecasts from ECHAM4.5 Atmospheric General Circulation Model (AGCM) forced with sea surface temperature forecasts and (b) daily climatological ensembles. The difference in skill between the above two quantifies the improvements that could be attainable using the AGCM forecasts. Monthly retrospective streamflow forecasts are developed from 1981 to 2010 and streamflow forecasts estimated from the VIC model are also compared with those predicted by using the principal component regression (PCR) model. The mean square error (MSE) in predicting monthly streamflows, using the VIC model, are compared with the MSE of streamflow climatology under ENSO (El Niño Southern Oscilation) conditions as well as under normal years. Results indicate that VIC forecasts obtained using ECHAM4.5 are significantly better than VIC forecasts obtained using climatological ensembles and PCR models over 2-6 month lead time during winter and spring seasons in capturing streamflow variability and reduced mean square errors. However, at 1-month lead time, streamflow utilizing the

  16. Changes in seasonality and timing of peak streamflow in snow and semi-arid climates of the north-central United States, 1910–2012

    USGS Publications Warehouse

    Ryberg, Karen R.; Akyüz, F. Adnan; Wiche, Gregg J.; Lin, Wei

    2015-01-01

    Changes in the seasonality and timing of annual peak streamflow in the north-central USA are likely because of changes in precipitation and temperature regimes. A source of long-term information about flood events across the study area is the U.S. Geological Survey peak streamflow database. However, one challenge of answering climate-related questions with this dataset is that even in snowmelt-dominated areas, it is a mixed population of snowmelt/spring rain generated peaks and summer/fall rain generated peaks. Therefore, a process was developed to divide the annual peaks into two populations, or seasons, snowmelt/spring, and summer/fall. The two series were then tested for the hypotheses that because of changes in precipitation regimes, the odds of summer/fall peaks have increased and, because of temperature changes, snowmelt/spring peaks happen earlier. Over climatologically and geographically similar regions in the north-central USA, logistic regression was used to model the odds of getting a summer/fall peak. When controlling for antecedent wet and dry conditions and geographical differences, the odds of summer/fall peaks occurring have increased across the study area. With respect to timing within the seasons, trend analysis showed that in northern portions of the study region, snowmelt/spring peaks are occurring earlier. The timing of snowmelt/spring peaks in three regions in the northern part of the study area is earlier by 8.7– 14.3 days. These changes have implications for water interests, such as potential changes in lead-time for flood forecasting or changes in the operation of flood-control dams.

  17. Snow cover, snowmelt and runoff in the Himalayan River basins

    NASA Technical Reports Server (NTRS)

    Dey, B.; Sharma, V. K.; Goswami, D. C.; Rao, P. Subba

    1988-01-01

    Not withstanding the seasonal vagaries of both rainfall amount and snowcover extent, the Himalayan rivers retain their basic perennial character. However, it is the component of snowmelt yield that accounts for some 60 to 70 percent of the total annual flow volumes from Hamilayan watersheds. On this large hydropotential predominantly depends the temporal performance of hydropower generation and major irrigation projects. The large scale effects of Himalayan snowcover on the hydrologic responses of a few selected catchments in western Himalayas was studied. The antecedent effects of snowcover area on long and short term meltwater yields can best be analyzed by developing appropriate hydrologic models forecasting the pattern of snowmelt as a function of variations in snowcover area. It is hoped that these models would be of practical value in the management of water resources. The predictability of meltwater for the entire snowmelt season was studied, as was the concurrent flow variation in adjacent watersheds, and their hydrologic significance. And the applicability of the Snowmelt-Runoff Model for real time forecast of daily discharges during the major part of the snowmelt season is examined.

  18. Canopy radiation transmission for an energy balance snowmelt model

    NASA Astrophysics Data System (ADS)

    Mahat, Vinod; Tarboton, David G.

    2012-01-01

    To better estimate the radiation energy within and beneath the forest canopy for energy balance snowmelt models, a two stream radiation transfer model that explicitly accounts for canopy scattering, absorption and reflection was developed. Upward and downward radiation streams represented by two differential equations using a single path assumption were solved analytically to approximate the radiation transmitted through or reflected by the canopy with multiple scattering. This approximation results in an exponential decrease of radiation intensity with canopy depth, similar to Beer's law for a deep canopy. The solution for a finite canopy is obtained by applying recursive superposition of this two stream single path deep canopy solution. This solution enhances capability for modeling energy balance processes of the snowpack in forested environments, which is important when quantifying the sensitivity of hydrologic response to input changes using physically based modeling. The radiation model was included in a distributed energy balance snowmelt model and results compared with observations made in three different vegetation classes (open, coniferous forest, deciduous forest) at a forest study area in the Rocky Mountains in Utah, USA. The model was able to capture the sensitivity of beneath canopy net radiation and snowmelt to vegetation class consistent with observations and achieve satisfactory predictions of snowmelt from forested areas from parsimonious practically available information. The model is simple enough to be applied in a spatially distributed way, but still relatively rigorously and explicitly represent variability in canopy properties in the simulation of snowmelt over a watershed.

  19. Snowmelt as a driver of ecosystem response in water limited mountain forests of the Western U.S.

    NASA Astrophysics Data System (ADS)

    Molotch, N. P.; Trujillo, E.

    2015-12-01

    Recent large-scale changes in snow cover over Western North America associated with climate warming may have widespread impacts on water availability. These changes have potentially varied impacts on water availability as snowmelt influences, soil moisture, streamflow, and evapotranspiration. These changes may significantly alter runoff production and gross primary productivity in mountain forests. Analysis of remotely sensed and in situ soil moisture data indicate strong sensitivities of the timing of peak soil moisture to the timing of snowmelt. Observations of vegetation greenness indicate strong forest and understory growth dependencies associated with snow accumulation, snowmelt, and soil moisture with peak snow water equivalent explaining 40-50% of inter-annual greenness variability in the Rocky Mountains. Examples of these dependencies will be presented based on the 2012 drought in the Southwestern US whereby near record low snow accumulation and record high potential evapotranspiration have resulted in record low forest greening as evident in the 30+ year satellite record. Forest response to aridity in 2012 was exacerbated by forest disturbance with greenness anomalies 90% greater in magnitude in Bark Beetle and Spruce Budworm affected areas versus undisturbed areas and 182% greater in magnitude in areas impacted by fire. Greenness sensitivities to aridity showed seasonal dependencies with record high Normalized Difference Vegetation Index (NDVI) values in April (14% above average) and record low NDVI values in July (7% below average). Gross primary productivity estimates from the Moderate Resolution Imaging Spectroradiometer (MODIS) and from the Niwot Ridge, Colorado Ameriflux tower indicate record high April GPP (30% and 90% above average for MODIS and the tower, respectively) and record low July GPP (19% and 30% below average, respectively). These energy, water, ecosystem relationships indicate that the sensitivity of ecosystems to changes in climate is

  20. Real-time streamflow conditions

    USGS Publications Warehouse

    Graczyk, David J.; Gebert, Warren A.

    1996-01-01

    Would you like to know streamflow conditions before you go fishing in Wisconsin or in more distant locations? Real-time streamflow data throughout Wisconsin and the United States are available on the Internet from the U.S. Geological Survey. You can see if the stream you are interested in fishing is high due to recent rain or low because of an extended dry spell. Flow conditions at more than 100 stream-gaging stations located throughout Wisconsin can be viewed by accessing the Wisconsin District Home Page at: http://wwwdwimdn.er.usgs.gov

  1. An Assessment of Melting Season Streamflow Forecasts using EPS for a Snow Dominated Basin in Turkey

    NASA Astrophysics Data System (ADS)

    Ertaş, Cansaran; Şensoy, Aynur; Akkol, Bulut; Şorman, Arda; Uysal, Gökçen; Çoşkun, Cihan

    2016-04-01

    In many mountainous regions, snowmelt makes significant contribution to streamflow, particularly during spring and summer months. Therefore, runoff modeling and forecasting during spring and early summer is important in terms of energy and water resources management. In this study, the Upper Euphrates Basin (10,275 km2 area and elevation range of 1125-3500 m) located at the headwater of Euphrates River, one of Turkey's most important rivers, is selected as the application area. In this region, snowmelt runoff constitutes approximately 2/3 in volume of the total yearly runoff. The aim of the study is to make a forward-oriented, medium-range flow forecasting using Ensemble Prediction System (EPS) which is a pioneer study for Turkey. Conceptual hydrological model HBV, which has a common usage in the literature, is chosen to predict streamflows. According to preliminary results, Nash-Sutcliffe model efficiencies are 0.85 for calibration (2001-2008) and 0.71 for validation (2009-2014) respectively. After calibrating/validating the hydrologic model, EPS data including 51 different combinations produced by ECMWF is used as probability based weather forecasts. Melting period during March-June of 2009-2015 is chosen as the forecast period. The probabilistic skill of EPS based hydrological model results are analyzed to verify the ensemble forecasts.

  2. Streamflow to the Gulf of Mexico

    USGS Publications Warehouse

    Judd, L.J.

    1995-01-01

    Fifty-four major streams discharging directly to the Gulf of Mexico and having drainage areas exceeding 200 square miles have been identified in the United States. Periods of record for daily values of streamflow and water quality are summarized for the lower reaches of each of these streams. Forty-four U.S. Geological Survey streamflow-gaging stations along the Gulf Coast with at least 40 years of daily streamflow data also were identified. These stations include most of the major streams and comprise 95 percent of the drainage area to the Gulf from the United States. Temporal trends are determined for daily mean streamflow for selected long-term stations for each of three streamflow perspectives: mean, minimum daily mean, and maximum daily mean. Distributions of monthly streamflow are determined for each of the 44 long-term stations. Temporal trends in streamflow and variations in monthly streamflow distributions are related to factors that affect streamflow: precipitation, land use, with- drawals, reservoir operations, and other factors. Trends in streamflow and variations in streamflow distributions at many stations are coincident with expected changes in streamflow caused by these factors.

  3. Runoff Efficiency of Sierra Snowmelt: Evaporative Water Losses in Wet vs. Dry Years

    NASA Astrophysics Data System (ADS)

    Lundquist, J.

    2007-12-01

    High altitude Sierra basins have negligible summer precipitation and very little groundwater storage, which makes them ideal laboratories for indirectly monitoring changes in evaporative losses between wet and dry years. Dry years have greater potential evapotranspiration, due to warmer June and July air temperatures, warmer summer water temperatures, greater solar radiation exposure, and longer growing seasons. However, dry years also have limited saturated surface areas as compared to wetter years, and thus actual evapotranspiration is much less than the potential in dry years. Assessing the balance of these factors is important in estimating the effect of warming temperatures and shrinking snowpacks on Sierra ecosystems. When spring and summer rain events are excluded from the analysis, the annual sum of basin snowmelt (calculated from 119 CA DWR snow pillows) minus the sum of March to October streamflow (calculated from USGS records at 10 high-elevation California river basins) indicates water losses from the basin. Assuming negligible groundwater storage from one year to the next, these water losses are a measure of evaporation and evapotranspiration (ET). Records from 1968 to 2005 show that the least amount of water is lost to ET in the wettest years, but the story for dry to normal years is more complicated. Conceptual models are used to test the sensitivity of annual ET to snow cover extent, length of summer season, moisture availability, basin elevation distribution, and air and water temperatures. Results are compared with observations.

  4. A spatially distributed energy balance snowmelt model for application in mountain basins

    NASA Astrophysics Data System (ADS)

    Marks, Danny; Domingo, James; Susong, Dave; Link, Tim; Garen, David

    1999-09-01

    Snowmelt is the principal source for soil moisture, ground-water re-charge, and stream-flow in mountainous regions of the western US, Canada, and other similar regions of the world. Information on the timing, magnitude, and contributing area of melt under variable or changing climate conditions is required for successful water and resource management. A coupled energy and mass-balance model ISNOBAL is used to simulate the development and melting of the seasonal snowcover in several mountain basins in California, Idaho, and Utah. Simulations are done over basins varying from 1 to 2500 km2, with simulation periods varying from a few days for the smallest basin, Emerald Lake watershed in California, to multiple snow seasons for the Park City area in Utah. The model is driven by topographically corrected estimates of radiation, temperature, humidity, wind, and precipitation. Simulation results in all basins closely match independently measured snow water equivalent, snow depth, or runoff during both the development and depletion of the snowcover. Spatially distributed estimates of snow deposition and melt allow us to better understand the interaction between topographic structure, climate, and moisture availability in mountain basins of the western US. Application of topographically distributed models such as this will lead to improved water resource and watershed management.

  5. Ensemble probabilistic streamflow generation using long-term MODIS snow product

    NASA Astrophysics Data System (ADS)

    Uysal, Gokcen; Sorman, Arda; Sensoy, Aynur

    2016-04-01

    Alternative techniques to generate streamflow provides more robust model sets for mountainous basins where there is data and model uncertainty due to harsh topography and atmospheric conditions. Dedicated satellite data have extensively increasing potential in water resources and using them in short and long term analysis will provide better understanding of accumulation and melting processes of snow. Snow covered area (SCA) is governed by various climatic and topographic parameters, besides it can be detected by optic satellites due to high reflectance in visible band. Snow probability can be calculated in each pixel from past records by assuming occurrence of snow within selected period. Probabilistic snow depletions curves (P-SDCs) can be derived using snow probability maps. In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) with visible/near-IR satellite daily P-SDCs are generated for melting period using daily cloud-free snow cover MOD10A images of 2001 - 2012 data. Study mainly aims to identify long term snow potential of the basin based on P-SDCs and the performances of probabilistic snow maps in snowmelt/runoff. Karasu (Upper Euphrates) Basin is one of the pilot basins having large snow covered areas contributing to high snowmelt during spring and large reservoirs located in the downstream indicate the need for an operational studies system in the region. Snowmelt Runoff Model (SRM) is calibrated and validated for the water years of 2002 - 2012 and ensemble streamflow estimations are generated for 2013-2015 melting periods. Ensemble forecasts are compared with observed discharges and each year shows high correlation with one of the cumulative probability ranges.

  6. Spring snowmelt variability in northern Eurasia 2000-2007

    NASA Astrophysics Data System (ADS)

    Bartsch, A.; Naeimi, V.; McCallum, I.; Shvidenko, A.; Wagner, W.

    2009-04-01

    Snowmelt dynamics play an essential role in the hydrological cycle of northern latitudes. Entire northern Eurasia is seasonally covered by snow. It instantaneously impacts not only surface hydrology and the energy budget but also terrestrial biota and thus the carbon cycle. Scatterometer such as SeaWinds Quikscat (Ku-band) are sensitive to changes at snow surfaces due to thaw and provide several measurements per day at high latitudes. Diurnal differences (frozen in the morning, thawed in the evening) are investigated in a range of studies since they indicate exactly when snowmelt is taking place. The actual number of dates of snow thaw is of most interest for glacier mass balance studies but the final disappearance of snow together with the length of spring thaw is required in regions with seasonal snow cover. Clusters of consecutive days of diurnal cycling of freeze/thaw are characteristic for the final snowmelt period in boreal and tundra environments. The start, end and duration of such periods give insight into spring CO2 emissions, vegetation fire prediction and river runoff behaviour. Results of the clustering of diurnal thaw and refreeze days as detected from active microwave satellite data over polar Eurasia is presented in this paper. The aim is the monitoring of spring snowmelt variability for assessment of impact of climate change on hydrology and energy budget. SeaWinds Quikscat measurements are available since 1999. The first entire snowmelt period on the northern hemisphere is covered in 2000. Large changes in backscatter between morning and evening acquisitions are characteristic for the snowmelt period, when freezing takes place over night and thawing of the surface during the day. A change from volume to surface scattering occurs in case of melting. When significant changes due to freeze/thaw cycling cease, closed snow cover also disappears. The exact day of year of beginning and end of freeze/thaw cycling can be clearly determined with

  7. The Snowmelt-Runoff Model (SRM) user's manual

    NASA Technical Reports Server (NTRS)

    Martinec, J.; Rango, A.; Major, E.

    1983-01-01

    A manual to provide a means by which a user may apply the snowmelt runoff model (SRM) unaided is presented. Model structure, conditions of application, and data requirements, including remote sensing, are described. Guidance is given for determining various model variables and parameters. Possible sources of error are discussed and conversion of snowmelt runoff model (SRM) from the simulation mode to the operational forecasting mode is explained. A computer program is presented for running SRM is easily adaptable to most systems used by water resources agencies.

  8. Modelling the effects of Prairie wetlands on streamflow

    NASA Astrophysics Data System (ADS)

    Shook, K.; Pomeroy, J. W.

    2015-12-01

    Recent research has demonstrated that the contributing areas of Prairie streams dominated by depressional (wetland) storage demonstrate hysteresis with respect to catchment water storage. As such contributing fractions can vary over time from a very small percentage of catchment area to the entire catchment during floods. However, catchments display complex memories of past storage states and their contributing fractions cannot be modelled accurately by any single-valued function. The Cold Regions Hydrological Modelling platform, CRHM, which is capable of modelling all of the hydrological processes of cold regions using a hydrological response unit discretization of the catchment, was used to further investigate dynamical contributing area response to hydrological processes. Contributing fraction in CRHM is also controlled by the episodic nature of runoff generation in this cold, sub-humid environment where runoff is dominated by snowmelt over frozen soils, snowdrifts define the contributing fraction in late spring, unfrozen soils have high water holding capacity and baseflow from sub-surface flow does not exist. CRHM was improved by adding a conceptual model of individual Prairie depression fill and spill runoff generation that displays hysteresis in the storage - contributing fraction relationship and memory of storage state. The contributing area estimated by CRHM shows strong sensitivity to hydrological inputs, storage and the threshold runoff rate chosen. The response of the contributing area to inputs from various runoff generating processes from snowmelt to rain-on-snow to rainfall with differing degrees of spatial variation was investigated as was the importance of the memory of storage states on streamflow generation. The importance of selecting hydrologically and ecologically meaningful runoff thresholds in estimating contributing area is emphasized.

  9. Coupling a Physically Based and Spatially Distributed Snowmelt Model with a Flowpath Model, Green Lakes Valley, Colorado Front Range

    NASA Astrophysics Data System (ADS)

    Liu, F.; Williams, M. W.; Ackerman, T.

    2003-12-01

    Spatially distributed estimates of snow deposition and melt allow us to better understand the interaction between hydrology and topographic structure and climate in mountain basins. Here we report on initial efforts to add a physical based and spatially distributed energy balance snowmelt model, ISNOBAL to the XTOP_PRMS model, a flowpath model coupling the TOPMODEL and Precipitation Runoff Modeling System within the Module Modeling System (MMS). This procedure was demonstrated at the 8-ha Martinelli and the 220-ha Green Lake 4 (GL4) catchments in the Green Lakes Valley, Colorado Front Range. In the pilot study using a temperature index snowmelt algorithm in the XTOP_PRMS model, streamflow discharge measured in 1996 was used to calibrate parameters and streamflow discharge was simulated from 1997 to 2000. The results showed that the discharge simulation was relatively successful at the 8-ha Martinelli catchment, with a Nash-Sutcliffe efficiency of 0.76. The t-test for paired means indicated that the prediction of discharge was not significantly different from the observation at α = 0.05 (n = 1611, p = 0.6). However, the discharge simulation was relatively poor at the GL4 catchment, with a Nash-Sutcliffe efficiency of only 0.54. Moreover, the difference between the predicted and observed values was significant at α = 0.05 (n = 1611, p = 0.005). It is believed that the poor performance of the XTOP_PRMS model at the GL4 catchment was due to use of the temperature index snowmelt algorithm as well as the coarse (daily) temporal resolution of the air temperature in the model. To resolve this problem, we report on our efforts to incorporate the hourly mode ISNOBAL with the XTOP_PRMS model within the MMS. High temporal resolution time-series images of climate surfaces such as air temperature, humidity, wind speed, precipitation, and solar and thermal radiation are generated using the Image Processing Workbench (IPW) and a combination of 3 to 5 point measurements

  10. Ephemeral-streamflow Induced Focused Recharge in the Desert Southwest (US)

    NASA Astrophysics Data System (ADS)

    Constantz, J. E.; Stonestrom, D. A.

    2015-12-01

    Multiyear studies examined meteorologic and hydrogeologic controls on ephemeral streamflow and focused groundwater recharge at 8 sites across arid and semiarid southwestern regions of the US. Intensive data collection targeted the Great Basin, Mojave Desert, Sonoran Desert, Rio Grande Rift, and Colorado Plateau physiographic areas (USGS Prof. Pap. 1703-C). During the study period (1997-2002), the region went from wetter than normal conditions associated with a strong El Niño climatic pattern (1997-1998) to drier than normal conditions associated with a La Niña climatic pattern. The 1997-1998 El Niño, the strongest in the modern instrumental record, roughly doubled precipitation at the Great Basin, Mojave Desert, and Colorado Plateau study sites. Precipitation at all sites thereafter trended sharply lower, producing moderate- to severe-drought conditions by the end of the study. Streamflow in regional rivers indicated diminishing groundwater recharge, with annual-flow volumes declining to levels of only 10-46% of their respective long-term averages by 2002. Local streamflows showed higher variability, reflecting smaller scales of integration (in time and space) within study-site watersheds. Toward the end of study, extended periods (9-15 months) of zero or negligible flow were observed at half the sites. Summer monsoonal rains generated the majority of streamflow and associated recharge in the Sonoran Desert sites and the more southerly Rio Grande Rift site, whereas winter storms and spring snowmelt dominated the northern and westernmost sites. Proximity to moisture sources and meteorologic fluctuations, in concert with orography, largely control the generation of focused groundwater recharge from ephemeral streamflow, although other aspects (geology, soil, and vegetation) were also identified as factors. Estimates of annual focused infiltration for the research sites ranged from about 105-107 cubic meters from contributing areas that ranged from 26-2,260 square

  11. Detection and attribution of streamflow timing changes to climate change in the Western United States

    USGS Publications Warehouse

    Hidalgo, H.G.; Das, T.; Dettinger, M.D.; Cayan, D.R.; Pierce, D.W.; Barnett, T.P.; Bala, G.; Mirin, A.; Wood, A.W.; Bonfils, Celine; Santer, B.D.; Nozawa, T.

    2009-01-01

    This article applies formal detection and attribution techniques to investigate the nature of observed shifts in the timing of streamflow in the western United States. Previous studies have shown that the snow hydrology of the western United States has changed in the second half of the twentieth century. Such changes manifest themselves in the form of more rain and less snow, in reductions in the snow water contents, and in earlier snowmelt and associated advances in streamflow "center" timing (the day in the "water-year" on average when half the water-year flow at a point has passed). However, with one exception over a more limited domain, no other study has attempted to formally attribute these changes to anthropogenic increases of greenhouse gases in the atmosphere. Using the observations together with a set of global climate model simulations and a hydrologic model (applied to three major hydrological regions of the western United States_the California region, the upper Colorado River basin, and the Columbia River basin), it is found that the observed trends toward earlier "center" timing of snowmelt-driven streamflows in the western United States since 1950 are detectably different from natural variability (significant at the p < 0.05 level). Furthermore, the nonnatural parts of these changes can be attributed confidently to climate changes induced by anthropogenic greenhouse gases, aerosols, ozone, and land use. The signal from the Columbia dominates the analysis, and it is the only basin that showed a detectable signal when the analysis was performed on individual basins. It should be noted that although climate change is an important signal, other climatic processes have also contributed to the hydrologic variability of large basins in the western United States. ?? 2009 American Meteorological Society.

  12. Potential Impacts of Climate Change on Streamflow and Flooding in Snow Dominated Forest Basins

    SciTech Connect

    Wigmosta, Mark S.; Leung, Lai R.

    2003-01-01

    Changes in climate resulting from the buildup of greenhouse gases in the atmosphere may impact significantly the frequency and magnitude of flooding in forested watersheds through changes in snowpack, soil moisture, and runoff production. The level of impact will vary considerably among watersheds depending on the climate regime and hydrologic characteristics of the catchments. Two forested watersheds in the Pacific Northwest of the United States, the American River and Middle Fork Flathead River, were studied to examine the influence of long-term global warming on streamflow and flooding in snowmelt dominated basins. These watersheds were selected to compare impacts resulting from changes in the maritime and continental climate regimes associated with the American and Middle Fork Flathead River basins, respectively. Output from a regional climate model was used to drive a distributed hydrologic model under present and future climate conditions corresponding to a doubling of atmospheric CO2. Under the future climate scenario more winter precipitation fell as rain instead of snow producing higher winter flows, a reduced snowpack, and decreased spring and summer flows in the American River. In addition, there was a large increase in the frequency and magnitude of winter flooding, primarily due to an increase in the number of rain-on-snow events. The change was much less dramatic in the Middle Fork Flathead River where flooding generally occurs during spring snowmelt. In this basin, the seasonal pattern of streamflow remains intact and the incidence of flooding was reduced under the future climate scenario. This study suggests the impacts of climate change on streamflow and flooding in forested watersheds are highly region specific.

  13. FROZEN GROUND CONTROL ON SNOWMELT FLOWPATHS AND SURFACE WATER CHEMISTRY IN TWO ALPINE BASINS

    EPA Science Inventory

    This study will increase our understanding of how snowmelt flowpaths are influenced by frozen ground in mid-latitude alpine basins. It also will elucidate how these flowpaths dictate surface water chemistry in relation to snowmelt.

  14. An approach for reconstructing past streamflows using a water balance model and tree-ring records in the upper West Walker River basin, California

    NASA Astrophysics Data System (ADS)

    Vittori, J. C.; Saito, L.; Biondi, F.

    2010-12-01

    Historical streamflows in a given river basin can be useful for determining regional patterns of drought and climate, yet such measured data are typically available for the last 100 years at most. To extend the measured record, observed streamflows can be regressed against tree-ring data that serve as proxies for streamflow. This empirical approach, however, cannot account for or test factors that do not directly affect tree-ring growth but may influence streamflow. To reconstruct past streamflows in a more mechanistic way, a seasonal water balance model has been developed for the upper West Walker River basin that uses proxy precipitation and air temperature data derived from tree-ring records as input. The model incorporates simplistic relationships between precipitation and other components of the hydrologic cycle, as well as a component for modeling snow, and operates at a seasonal time scale. The model allows for flexibility in manipulating various hydrologic and land use characteristics, and can be applied to other watersheds. The intent is for the model to investigate sources of uncertainty in streamflow reconstructions, and how factors such as wildfire or changes in vegetation cover could impact estimates of past flows, something regression-based models are not able to do. In addition, the use of a mechanistic water balance model calibrated against proxy climate records can provide information on changes in various components of the water cycle, including the interaction between evapotranspiration, snowmelt, and runoff under warmer climatic regimes.

  15. Use of medium-range numerical weather prediction model output to produce forecasts of streamflow

    USGS Publications Warehouse

    Clark, M.P.; Hay, L.E.

    2004-01-01

    he accuracy of precipitation forecasts over the northeastern United States, but overall, the accuracy of MOS-based precipitation forecasts is slightly lower than the raw NCEP forecasts. Four basins in the United States were chosen as case studies to evaluate the value of MRF output for predictions of streamflow. Streamflow forecasts using MRF output were generated for one rainfall-dominated basin (Alapaha River at Statenville, Georgia) and three snowmelt-dominated basins (Animas River at Durango, Colorado: East Fork of the Carson River near Gardnerville, Nevada: and Cle Elum River near Roslyn, Washington). Hydrologic model output forced with measured-station data were used as "truth" to focus attention on the hydrologic effects of errors in the MRF forecasts. Eight-day streamflow forecasts produced using the MOS-corrected MRF output as input (MOS) were compared with those produced using the climatic Ensemble Streamflow Prediction (ESP) technique. MOS-based streamflow forecasts showed increased skill in the snowmelt-dominated river basins, where daily variations in streamflow are strongly forced by temperature. In contrast, the skill of MOS forecasts in the rainfall-dominated basin (the Alapaha River) were equivalent to the skill of the ESP forecasts. Further improvements in streamflow forecasts require more accurate local-scale forecasts of precipitation and temperature, more accurate specification of basin initial conditions, and more accurate model simulations of streamflow. ?? 2004 American Meteorological Society.

  16. Analysis of trends in climate, streamflow, and stream temperature in north coastal California

    USGS Publications Warehouse

    Madej, M.A.

    2011-01-01

    As part of a broader project analyzing trends in climate, streamflow, vegetation, salmon, and ocean conditions in northern California national park units, we compiled average monthly air temperature and precipitation data from 73 climate stations, streamflow data from 21 river gaging stations, and limited stream temperature data from salmon-bearing rivers in north coastal California. Many climate stations show a statistically significant increase in both average maximum and average minimum air temperature in early fall and midwinter during the last century. Concurrently, average September precipitation has decreased. In many coastal rivers, summer low flow has decreased and summer stream temperatures have increased, which affects summer rearing habitat for salmonids. Nevertheless, because vegetative cover has also changed during this time period, we cannot ascribe streamflow changes to climate change without first assessing water budgets. Although shifts in the timing of the centroid of runoff have been documented in snowmelt-dominated watersheds in the western United States, this was not the case in lower elevation coastal rivers analyzed in this study.

  17. Precipitation-snowmelt timing and snowmelt augmentation of large peak flow events, western Cascades, Oregon

    NASA Astrophysics Data System (ADS)

    Jennings, Keith; Jones, Julia A.

    2015-09-01

    This study tested multiple hydrologic mechanisms to explain snowpack dynamics in extreme rain-on-snow floods, which occur widely in the temperate and polar regions. We examined 26, 10 day large storm events over the period 1992-2012 in the H.J. Andrews Experimental Forest in western Oregon, using statistical analyses (regression, ANOVA, and wavelet coherence) of hourly snowmelt lysimeter, air and dewpoint temperature, wind speed, precipitation, and discharge data. All events involved snowpack outflow, but only seven events had continuous net snowpack outflow, including three of the five top-ranked peak discharge events. Peak discharge was not related to precipitation rate, but it was related to the 10 day sum of precipitation and net snowpack outflow, indicating an increased flood response to continuously melting snowpacks. The two largest peak discharge events in the study had significant wavelet coherence at multiple time scales over several days; a distribution of phase differences between precipitation and net snowpack outflow at the 12-32 h time scale with a sharp peak at π/2 radians; and strongly correlated snowpack outflow among lysimeters representing 42% of basin area. The recipe for an extreme rain-on-snow event includes persistent, slow melt within the snowpack, which appears to produce a near-saturated zone within the snowpack throughout the landscape, such that the snowpack may transmit pressure waves of precipitation directly to streams, and this process is synchronized across the landscape. Further work is needed to understand the internal dynamics of a melting snowpack throughout a snow-covered landscape and its contribution to extreme rain-on-snow floods.

  18. Incorporating Watershed-Scale Groundwater/Surface Water Interactions to Better Understand How ENSO/PDO Teleconnections Affect Streamflow Variability in Geologically Complex, Semiarid, Snow-Dominated Mountainous Watersheds

    NASA Astrophysics Data System (ADS)

    Tsinnajinnie, L.; Frisbee, M. D.; Wilson, J. L.

    2014-12-01

    In the Southwestern U.S., warm anomalies in the El Nino-Southern Oscillation (ENSO) are associated with increased probability of wetter than normal winter precipitation. For semiarid, snow-dominated mountainous watersheds, teleconnections, such as ENSO, may strongly affect the magnitude and timing of snowmelt pulses in streamflow. In examining stream-gage data, an implicit assumption is made that all the streamflow generation processes operative within the watershed are captured by the stream gage. However, zones of strong groundwater discharge to the stream alternating with zones of strong recharge from the stream may emerge in geologically complex watersheds. The spatial complexity of these groundwater/surface water interactions may not be captured in the stream-gage discharge data. This may not be a problem in watersheds where streamflow is generated primarily by shallow, fast runoff processes. In that case, changes associated with ENSO can be quickly apparent in streamflow (i.e., an increase in snowpack associated with warm ENSO anomalies will quickly translate to increases in daily and peak streamflow). However, the spatial complexity of groundwater/surface water interactions creates a problem in geologically complex watersheds where interactions with deep, regional groundwater are present. In this case, we test the hypothesis that the combined effect of complex geology and deep groundwater interactions creates phase shifts between peak snowpack, onset and peak of snowmelt pulses, and teleconnection indices. Using time-series analysis, the relationships between teleconnections, and metrics for snowpack and streamflow are evaluated for selected watersheds in New Mexico, Arizona, and Colorado. A phase shift (lag) is observed between the Oceanic Nino Index (ONI) and onset and peak of snowmelt pulses in streamflow in snow-dominated watersheds with complex geology across scales of 50 to 1600 km2. Additionally, strong relationships between teleconnections and

  19. Response of streamflow to projected climate change scenarios in an eastern Himalayan catchment of India

    NASA Astrophysics Data System (ADS)

    Senzeba, K. T.; Rajkumari, S.; Bhadra, A.; Bandyopadhyay, A.

    2016-04-01

    Snowmelt run-off model (SRM) based on degree-day approach has been employed to evaluate the change in snow-cover depletion and corresponding streamflow under different projected climatic scenarios for an eastern Himalayan catchment in India. Nuranang catchment located at Tawang district of Arunachal Pradesh with an area of 52 km2 is selected for the present study with an elevation range of 3143-4946 m above mean sea level. Satellite images from October to June of the selected hydrological year 2006-2007 were procured from National Remote Sensing Centre, Hyderabad. Snow cover mapping is done using NDSI method. Based on long term meteorological data, temperature and precipitation data of selected hydrological year are normalized to represent present climatic condition. The projected temperature and precipitation data are downloaded from NCAR's GIS data portal for different emission scenarios (SRES), viz., A1B, A2, B1; and IPCC commitment (non-SRES) scenario for different future years (2020, 2030, 2040 and 2050). Projected temperature and precipitation data are obtained at desired location by spatially interpolating the gridded data and then by statistical downscaling using linear regression. Snow depletion curves for all projected scenarios are generated for the study area and compared with conventional depletion curve for present climatic condition. Changes in cumulative snowmelt depth for different future years are highest under A1B and lowest under IPCC commitment, whereas A2 and B1 values are in-between A1B and IPCC commitment. Percentage increase in streamflow for different future years follows almost the same trend as change in precipitation from present climate under all projected climatic scenarios. Hence, it was concluded that for small catchments having seasonal snow cover, the total streamflow under projected climatic scenarios in future years will be primarily governed by the change in precipitation and not by change in snowmelt depth. Advancing of

  20. Climate Change Impacts to Hydro Power Reservoir Systems in British Columbia, Canada: Modelling, Validation and Projection of Historic and Future Streamflow and Snowpack

    NASA Astrophysics Data System (ADS)

    Bennett, K. E.; Schnorbus, M.; Werner, A. T.; Berland, A. J.

    2010-12-01

    The British Columbia Hydro Electric Corporation (BC Hydro) has a mandate to provide clean, renewable and reliable sources of hydro-electric power into the future, hence managing those resources in the context of climate change will be an important component of reservoir operational planning in British Columbia. The Pacific Climate Impacts Consortium (www.PacificClimate.org) has implemented the Variable Infiltration Capacity hydrologic model parameterized at 1/16th degree (~32 km2) to provide BC Hydro with future projections of changes to streamflow and snowpack to the 2050s. The headwaters of the Peace, Columbia, and Campbell River basins were selected for study; the Upper Peace River basin (101,000 km2) is a snowmelt-dominated watershed, and the Upper Columbia River Basin (104,000 km2) has a mixed snowmelt-glacier melt runoff regime, with glacier runoff contributing up to 15 to 20% of late summer discharge. The Upper Campbell River watershed (1,200 km2) has a mixed rainfall and snowmelt (hybrid) hydrologic regime. The model has been calibrated using historical streamflow observations and validated against these observations, as well as automated snow pillow measurements. Future streamflow changes are estimated based on eight Global Climate Models (GCMs) from the CMIP3 suite, downscaled using the Bias Correction Spatial Downscaling (BCSD) technique, run under three emissions scenarios (A2, A1B and B1; A1B is specifically reported on herein). Climate impacts by the 2050s in the three watersheds illustrate an increase in annual average temperature and precipitation ranging between +2.2°C to +2.8°C and +2% to +10% depending on basin, and an annual change in streamflow of -1% to +12% for the three watersheds. Changes are more profound on the seasonal time-scale and differ across basins. Summer streamflow in the Upper Campbell River watershed is projected to decline by -60%, where as the Upper Peace and Columbia systems are projected to decline by -25% and -22

  1. Age Discrimination--Notice--Filing Notice of Intent to Sue Within 180 Days After the Alleged Violation Is a Jurisdictional Prerequisite to an Action Under the Age Discrimination in Employment Act. Hiscott v. General Elec. Co., 521 F. 2d 632 (6th Cir. 1975)

    ERIC Educational Resources Information Center

    Stiltner, L. Del

    1976-01-01

    The Hiscott decision indicates that the court will require notice to meet specific standards before an individual's right to maintain a civil action under the ADEA becomes operative. It also suggests that strict compliance with the 180-day notice provision will continue to be a condition precedent to suit. (Author/LBH)

  2. Seasonal and successional streamflow response to forest cutting and regrowth in the northwest and eastern United States

    NASA Astrophysics Data System (ADS)

    Jones, Julia A.; Post, David A.

    2004-05-01

    This study examined daily streamflow response over up to four decades in northwest conifer forest and eastern deciduous forest sites in the United States. We used novel methods to analyze daily observations of climate and streamflow spanning more than 900 basin years of record at 14 treated/control basin pairs where forest removal and regrowth experiments were underway in the period 1930-2002. In the 1 to 5-year period after forest removal, maximum daily increases ranged from 2 to 3 mm at deciduous forest sites, to 6 to 8 mm at conifer forest sites. Significant spring surpluses persisted for up to 35 years in conifer forest basins, but winter and spring streamflow deficits appeared after 10 to 15 years of forest regrowth in eastern deciduous forest basins. In all 5-yr posttreatment periods, absolute changes in daily streamflow were significantly more likely during moist, warm seasons, or during snowmelt seasons, but relative changes were more likely during warm seasons irrespective of moisture status. Both relative and absolute streamflow changes in the 1 to 5 and 15 to 25-year periods after forest removal were significantly positively related to the age of the forest at the time it was cut. Eastern deciduous forests had been disturbed by logging or hurricane 12 to 56 years prior to forest removal, while Pacific Northwest conifer forests had been not experienced logging or wildfire for 90 to 450 years. Paired basin experiments provide a continuous, and continuously changing, record of vegetation structure, composition, and climate, and their effects on streamflow.

  3. Snowmelt-runoff Model Utilizing Remotely-sensed Data

    NASA Technical Reports Server (NTRS)

    Rango, A.

    1985-01-01

    Remotely sensed snow cover information is the critical data input for the Snowmelt-Runoff Model (SRM), which was developed to simulatke discharge from mountain basins where snowmelt is an important component of runoff. Of simple structure, the model requires only input of temperature, precipitation, and snow covered area. SRM was run successfully on two widely separated basins. The simulations on the Kings River basin are significant because of the large basin area (4000 sq km) and the adequate performance in the most extreme drought year of record (1976). The performance of SRM on the Okutadami River basin was important because it was accomplished with minimum snow cover data available. Tables show: optimum and minimum conditions for model application; basin sizes and elevations where SRM was applied; and SRM strengths and weaknesses. Graphs show results of discharge simulation.

  4. Influences of Main Large-Scale Climate Indices on Canada's Streamflow Trends over the Past Several Decades

    NASA Astrophysics Data System (ADS)

    Nalley, D.; Adamowski, J. F.; Biswas, A.; Khalil, B.

    2015-12-01

    The main objective of this study is to examine the influence of three important large-scale climate indices influencing the Canadian climate on Canada's monthly streamflow trends. These main climate indices are El-Niño Southern Oscillation (ENSO), the North Atlantic Oscillation (NAO), and Pacific Decadal Oscillation (PDO). This study combines the use of wavelet transform techniques and the Mann-Kendall (MK) trend test in order to achieve its main objective. The MK test was used to analyze trends and determine the starting point of trends in streamflow data. The continuous wavelet transform (CWT) was used to extract the time-frequency information of the streamflow and climate index data used. Only streamflow data from gauging stations that are categorized as natural and have a minimum of 40 years of complete records were used in the study - there are 73 gauging stations that met these requirements. Starting points of trends varied from station to station, and the CWT obtained show variabilities at the intra-annual, inter-annual and inter-decadal scales. Wavelet coherence spectra indicate that the influences of ENSO and the NAO indices occur at the 2-6-year time scales, and the influences of the PDO index are more apparent at time scales of up to 8 years and greater than 16 years. In particular, all CWT spectra of streamflow consistently show significant variability at the 6-12 months scales (which may be related to seasonality events such as spring snowmelt). The 6-12 month frequencies were isolated from the streamflow data and Spearman's correlation coefficients were used to identify the amount of time streamflow activities lagged behind the influence of each climate index. This study observed that dominant sources of streamflow variations at periodic scales of 6-12 months, are more significantly influenced by NAO and PDO indices compared with ENSO. The results obtained from this study can be used by water managers and planners in different regions of Canada to

  5. Streamflow Responses and Ecological Implications of Climate Change in New York City Water Supply Watershed

    NASA Astrophysics Data System (ADS)

    Pradhanang, S. M.; Mukundan, R.; Schneiderman, E.; Zion, M. S.; Swamy, A.; Pierson, D. C.; Frei, A.; Easton, Z. M.; Fuka, D. R.; Steenhuis, T. S.

    2011-12-01

    The impact of climate change in the North East United States is already observed in the form of shorter winter, higher annual average temperature, and more frequent extreme heat and precipitation events. These changes could have profound effects on the New York City (NYC) Water Supply and ecological integrity of the watersheds; and the implications of such changes are not well understood. The objective of this study is to examine how future changes in precipitation and air temperature may translate into changes in streamflow in the NYC Water Supply watershed using the Soil and Water Assessment Tool-Water Balance (SWAT-WB). A comparative analysis between simulated streamflow for baseline period (1964-2008) and future scenarios (2081-2100) was carried out for streamflow indicators that are important for understanding how river flow dynamics will impact the water supply, aquatic health, and physical structures in the stream corridor. We analyze the impacts of changes in the magnitude, timing, duration, frequency, and rate of hydrologic events using the Indicators of Hydrologic Alteration (IHA) tool. Our results indicate that warming during the winter and the early spring diminishes snowpack and influence timing of snowmelt. The winter and spring streamflow are projected to increase but summer will be drier in future. Decreased flow during April and summer months will influence timing of fish spawning and their habitats. Low flows, hydrograph pulses, rise and fall rates are expected to increase due to climate change, potentially creating unfavorable conditions for native species and aquatic invertebrates inhabiting along river's edge, and affecting stream bank stability and physical structures.

  6. Impact of improved snowmelt modelling in a monthly hydrological model.

    NASA Astrophysics Data System (ADS)

    Folton, Nathalie; Garcia, Florine

    2016-04-01

    The quantification and the management of water resources at the regional scale require hydrological models that are both easy to implement and efficient. To be reliable and robust, these models must be calibrated and validated on a large number of catchments that are representative of various hydro-meteorological conditions, physiographic contexts, and specific hydrological behavior (e.g. mountainous catchments). The GRLoiEau monthly model, with its simple structure and its two free parameters, answer our need of such a simple model. It required the development of a snow routine to model catchments with temporarily snow-covered areas. The snow routine developed here does not claim to represent physical snowmelt processes but rather to simulate them globally on the catchment. The snowmelt equation is based on the degree-day method which is widely used by the hydrological community, in particular in engineering studies (Etchevers 2000). A potential snowmelt (Schaefli et al. 2005) was computed, and the parameters of the snow routine were regionalized for each mountain area. The GRLoiEau parsimonious structure requires meteorological data. They come from the distributed mesoscale atmospheric analysis system SAFRAN, which provides estimations of daily solid and liquid precipitations and temperatures on a regular square grid at the spatial resolution of 8*8 km², throughout France. Potential evapotranspiration was estimated using the formula by Oudin et al. (2005). The aim of this study is to improve the quality of monthly simulations for ungauged basins, in particular for all types of mountain catchments, without increasing the number of free parameters of the model. By using daily SAFRAN data, the production store and snowmelt can be run at a daily time scale. The question then arises whether simulating the monthly flows using a production function at a finer time step would improve the results. And by using the SAFRAN distributed climate series, a distributed approach

  7. Contribution of MODIS Derived Snow Cover Satellite Data into Artificial Neural Network for Streamflow Estimation

    NASA Astrophysics Data System (ADS)

    Uysal, Gokcen; Arda Sorman, Ali; Sensoy, Aynur

    2014-05-01

    Contribution of snowmelt and correspondingly snow observations are highly important in mountainous basins for modelers who deal with conceptual, physical or soft computing models in terms of effective water resources management. Long term archived continuous data are needed for appropriate training and testing of data driven approaches like artificial neural networks (ANN). Data is scarce at the upper elevations due to the difficulty of installing sufficient automated SNOTEL stations; thus in literatures many attempts are made on the rainfall dominated basins for streamflow estimation studies. On the other hand, optical satellites can easily detect snow because of its high reflectance property. MODIS (Moderate Resolution Imaging Spectroradiometer) satellite that has two platforms (Terra and Aqua) provides daily and 8-daily snow images for different time periods since 2000, therefore snow cover data (SCA) may be useful as an input layer for ANN applications. In this study, a multi-layer perceptron (MLP) model is trained and tested with precipitation, temperature, radiation, previous day discharges as well as MODIS daily SCA data. The weights and biases are optimized with fastest and robust Levenberg-Marquardt backpropagation algorithm. MODIS snow cover images are removed from cloud coverage using certain filtering techniques. The Upper Euphrates River Basin in eastern part of Turkey (10 250 km2) is selected as the application area since it is fed by snowmelt approximately 2/3 of total annual volume during spring and early summer. Several input models and ANN structures are investigated to see the effect of the contributions using 10 years of data (2001-2010) for training and validation. The accuracy of the streamflow estimations is checked with statistical criteria (coefficient of determination, Nash-Sutcliffe model efficiency, root mean square error, mean absolute error) and the results seem to improve when SCA data is introduced. Furthermore, a forecast study is

  8. Low Streamflow Forcasting using Minimum Relative Entropy

    NASA Astrophysics Data System (ADS)

    Cui, H.; Singh, V. P.

    2013-12-01

    Minimum relative entropy spectral analysis is derived in this study, and applied to forecast streamflow time series. Proposed method extends the autocorrelation in the manner that the relative entropy of underlying process is minimized so that time series data can be forecasted. Different prior estimation, such as uniform, exponential and Gaussian assumption, is taken to estimate the spectral density depending on the autocorrelation structure. Seasonal and nonseasonal low streamflow series obtained from Colorado River (Texas) under draught condition is successfully forecasted using proposed method. Minimum relative entropy determines spectral of low streamflow series with higher resolution than conventional method. Forecasted streamflow is compared to the prediction using Burg's maximum entropy spectral analysis (MESA) and Configurational entropy. The advantage and disadvantage of each method in forecasting low streamflow is discussed.

  9. Streamflow forecasting using functional regression

    NASA Astrophysics Data System (ADS)

    Masselot, Pierre; Dabo-Niang, Sophie; Chebana, Fateh; Ouarda, Taha B. M. J.

    2016-07-01

    Streamflow, as a natural phenomenon, is continuous in time and so are the meteorological variables which influence its variability. In practice, it can be of interest to forecast the whole flow curve instead of points (daily or hourly). To this end, this paper introduces the functional linear models and adapts it to hydrological forecasting. More precisely, functional linear models are regression models based on curves instead of single values. They allow to consider the whole process instead of a limited number of time points or features. We apply these models to analyse the flow volume and the whole streamflow curve during a given period by using precipitations curves. The functional model is shown to lead to encouraging results. The potential of functional linear models to detect special features that would have been hard to see otherwise is pointed out. The functional model is also compared to the artificial neural network approach and the advantages and disadvantages of both models are discussed. Finally, future research directions involving the functional model in hydrology are presented.

  10. A Method of Streamflow Drought Analysis

    NASA Astrophysics Data System (ADS)

    Zelenhasić, Emir; Salvai, Atila

    1987-01-01

    A method of completely describing and analyzing the stochastic process of streamflow droughts has been recommended. All important components of streamflow droughts such as deficit, duration, time of occurrence, number of streamflow droughts in a given time interval [0, t], the largest streamflow drought deficit, and the largest streamflow drought duration in a given time interval [0, t] are taken into consideration. A streamflow drought is related here to streamflow deficit. Following the theory of the supremum of a random number of random variables a stochastic model is presented for interpretation and analysis of the largest streamflow drought deficit below a given reference discharge and the largest streamflow drought duration concerning a time interval [0, t], at a given location of a river. The method is based on the assumption that streamflow droughts are independent, identically distributed random variables and that their occurrence is subject to the Poisson probability law. This paper is actually a continuation of the previous E. Zelenhasić (1970, 1979, 1983) and P. Todorović (1970) works on the extremes in hydrology. Application of the method is made on the 58-year record of the Sava River at Sr. Mitrovica and on the 52-year record of Tisa River at Senta, Yugoslavia, and good agreement is found between the theoretical and empirical distribution functions for all analyzed drought components for both rivers. Only one complete example, the Sava River at Sr. Mitrovica, is given in the paper. The proposed method deals with hydrograph recessions of daily or instantaneous discharges in the region of low flows, and not with mean annual flows which were used by other investigators.

  11. Taking the pulse of snowmelt: in situ sensors reveal seasonal, event and diurnal patterns of nitrate and dissolved organic matter variability in an upland forest stream

    USGS Publications Warehouse

    Pellerin, Brian A.; Saraceno, John Franco; Shanley, James B.; Sebestyen, Stephen D.; Aiken, George R.; Wollheim, Wilfred M.; Bergamaschi, Brian A.

    2011-01-01

    Highly resolved time series data are useful to accurately identify the timing, rate, and magnitude of solute transport in streams during hydrologically dynamic periods such as snowmelt. We used in situ optical sensors for nitrate (NO3-) and chromophoric dissolved organic matter fluorescence (FDOM) to measure surface water concentrations at 30 min intervals over the snowmelt period (March 21–May 13, 2009) at a 40.5 hectare forested watershed at Sleepers River, Vermont. We also collected discrete samples for laboratory absorbance and fluorescence as well as δ18O–NO3- isotopes to help interpret the drivers of variable NO3- and FDOM concentrations measured in situ. In situ data revealed seasonal, event and diurnal patterns associated with hydrological and biogeochemical processes regulating stream NO3- and FDOM concentrations. An observed decrease in NO3- concentrations after peak snowmelt runoff and muted response to spring rainfall was consistent with the flushing of a limited supply of NO3- (mainly from nitrification) from source areas in surficial soils. Stream FDOM concentrations were coupled with flow throughout the study period, suggesting a strong hydrologic control on DOM concentrations in the stream. However, higher FDOM concentrations per unit streamflow after snowmelt likely reflected a greater hydraulic connectivity of the stream to leachable DOM sources in upland soils. We also observed diurnal NO3- variability of 1–2 μmol l-1 after snowpack ablation, presumably due to in-stream uptake prior to leafout. A comparison of NO3- and dissolved organic carbon yields (DOC, measured by FDOM proxy) calculated from weekly discrete samples and in situ data sub-sampled daily resulted in small to moderate differences over the entire study period (-4 to 1% for NO3- and -3 to -14% for DOC), but resulted in much larger differences for daily yields (-66 to +27% for NO3- and -88 to +47% for DOC, respectively). Despite challenges inherent in in situ sensor

  12. Rainfall and snow-melt triggered glacial lake outbursts: a systematic analysis of the Kedarnath (Uttarakhand, India), June 2013 disaster

    NASA Astrophysics Data System (ADS)

    Allen, Simon; Rastner, Philipp; Arora, Manohar; Huggel, Christian; Stoffel, Markus

    2015-04-01

    Heavy rainfall in early June 2013 triggered flash flooding and landslides throughout the Indian Himalayan state of Uttarakhand, killing more than 6000 people. The destruction of roads and trekking routes left around 100,000 pilgrims and tourists stranded. Most fatalities and damages resulted directly from a lake outburst and debris flow disaster originating from above the village of Kedarnath on June 16 and 17. Here we provide a first systematic analysis of the contributing factors leading to the Kedarnath disaster, both in terms of hydro-meteorological triggering (rainfall, snowmelt, and temperature) and topographic predisposition. Specifically, the topographic characteristics of the Charobari lake watershed above Kedarnath are compared with other glacial lakes across the northwestern Indian Himalayan states of Uttarakhand and Himachal Pradesh, and implications for glacier lake outburst hazard assessment in a changing climate are discussed. Our analysis suggests that the early onset of heavy monsoon rainfall (390 mm, June 10 - 17) immediately following a prolonged four week period of unusually rapid snow cover depletion and elevated streamflow is the crucial hydro-meteorological factor, resulting in slope saturation and significant runoff into the small seasonal glacial lake. Over a four week period the MODIS-derived snow covered area above Kedarnath decreased nearly 50%, from above average coverage in mid-May to well below average coverage by the second week of June. Such a rapid decrease has not been observed in the previous 13-year record, where the average decrease in snow covered area over the same four week window is only 15%. The unusual situation of the lake being dammed in a steep, unstable paraglacial environment, but fed entirely from snow-melt and rainfall within a fluvial dominated watershed is important in the context of this disaster. A simple scheme enabling large-scale recognition of such an unfavorable topographic setting is presented, and on the

  13. Management of the Spring Snowmelt Recession in Regulated Systems

    NASA Astrophysics Data System (ADS)

    Yarnell, S. M.; Lind, A.; Epke, G.; Viers, J. H.

    2013-12-01

    In unregulated rivers in the Sierra Nevada mountains of California, the spring snowmelt recession links high winter flows to low summer baseflow and is a consistent and predictable portion of the annual hydrograph. Consequently, it is an important resource to both riverine ecosystems and California's water supply. In regulated river systems where the spring snowmelt recession is often captured behind dams or diverted for hydropower, restoration of a more natural spring flow regime can provide distinct ecological benefits, such as breeding and migration cues for native species, increased habitat availability, and greater hydraulic habitat diversity. However, knowledge of how to create and manage an ecologically beneficial spring snowmelt recession in a regulated river system has been lacking. This study defined a methodology by which spring flow regimes can be modeled in regulated systems from the quantifiable characteristics of spring snowmelt recessions in unregulated rivers. Using fundamental flow components such as magnitude, timing, and rate of change, the spring snowmelt recession in eight unregulated rivers across the Sierra Nevada range was quantified to gain a better understanding of the predictability and variability across watersheds. The analysis found that unregulated Sierran systems behaved similarly with respect to seasonal patterns and flow recession shape (i.e., recession limb curvature), and thus flows could be modeled in a manner that mimics those predictable characteristics. Using this methodology that quantifies spring recession flows in terms of a daily percent decrease in flow, a series of flow recession scenarios were then created for application on a regulated Sierran river. Four scenarios, ranging from a slow natural recession to a short fast recession typically observed in regulated rivers following cessation of high flow spills, were evaluated within a 2D hydrodynamic model. The effects of the flows on suitable habitat for Foothill yellow

  14. Overland Flow Induced by Snowmelt and Partially Frozen Conditions

    NASA Astrophysics Data System (ADS)

    Stolte, J.; French, H.

    2007-12-01

    The transport infrastructure is a vital part of the society, with high capital investments. Design of this system is therefore very important. Climate changes will increase the frequency of extreme precipitation events, floods and snow melt periods experienced by the infrastructure. According to initial analysis by the Norwegian transport sector these changes will affect road maintenance, emergency planning, design of new roads and infrastructure. Increased frequency of floods is expected to cause more closed roads because of insufficient and badly maintained drainage systems. Increased ground frost and ice formation on ground surface cause large increases in surface runoff during snowmelt. Recently, in Norway the ClimRunoff project has started with the focus on quantifying discharge of catchment areas draining towards roads. The first priority of the project is to create a model that can evaluate the run-off situations under spring situation (i.e. overland flow due to snowmelt and partially frozen soils). The model is tested on a well-defined catchment under autumn situation. Preliminary results of the model calculations will be presented, together with the challenges to alter the model to be able to calculate snowmelt and frozen soil conditions. In close cooperation with the Norwegian road authorities, areas with historical flooding events are selected, and current and future climate data will be used to analyse the infrastructure of the road construction. Together with a risk analysis of the vulnerability of the transport infrastructure the model will be used to create guidelines for road construction with respect to run-off and drainage that can account for changes in climate.

  15. The Impact of Changing Snowmelt Timing on Non-Irrigated Crop Yield in Idaho

    NASA Astrophysics Data System (ADS)

    Murray, E. M.; Cobourn, K.; Flores, A. N.; Pierce, J. L.; Kunkel, M. L.

    2013-12-01

    The impacts of climate change on water resources have implications for both agricultural production and grower welfare. Many mountainous regions in the western U.S. rely on snowmelt as the dominant surface water source, and in Idaho, reconstructions of spring snowmelt timing have demonstrated a trend toward earlier, more variable snowmelt dates within the past 20 years. This earlier date and increased variability in snowmelt timing have serious implications for agriculture, but there is considerable uncertainty about how agricultural impacts vary by region, crop-type, and practices like irrigation vs. dryland farming. Establishing the relationship between snowmelt timing and agricultural yield is important for understanding how changes in large-scale climatic indices (like snowmelt date) may be associated with changes in agricultural yield. This is particularly important where local practitioner behavior is influenced by historically observed relationships between these climate indices and yield. In addition, a better understanding of the influence of changes in snowmelt on non-irrigated crop yield may be extrapolated to better understand how climate change may alter biomass production in non-managed ecosystems. To investigate the impact of snowmelt date on non-irrigated crop yield, we developed a multiple linear regression model to predict historical wheat and barley yield in several Idaho counties as a function of snowmelt date, climate variables (precipitation and growing degree-days), and spatial differences between counties. The relationship between snowmelt timing and non-irrigated crop yield at the county level is strong in many of the models, but differs in magnitude and direction for the two different crops. Results show interesting spatial patterns of variability in the correlation between snowmelt timing and crop yield. In four southern counties that border the Snake River Plain and one county bordering Oregon, non-irrigated wheat and/or barley yield are

  16. Hydrologic response of an alpine watershed: Application of a meteorological wireless sensor network to understand streamflow generation

    NASA Astrophysics Data System (ADS)

    Simoni, S.; Padoan, S.; Nadeau, D. F.; Diebold, M.; Porporato, A.; Barrenetxea, G.; Ingelrest, F.; Vetterli, M.; Parlange, M. B.

    2011-10-01

    A field measurement campaign was conducted from June to October 2009 in a 20 km2 catchment of the Swiss Alps with a wireless network of 12 weather stations and river discharge monitoring. The objective was to investigate the spatial variability of meteorological forcing and to assess its impact on streamflow generation. The analysis of the runoff dynamics highlighted the important contribution of snowmelt from spring to early summer. During the entire experimental period, the streamflow discharge was dominated by base flow contributions with temporal variations due to occasional rainfall-runoff events and a regular contribution from glacier melt. Given the importance of snow and ice melt runoff in this catchment, patterns of near-surface air temperatures were studied in detail. Statistical data analyses revealed that meteorological variables inside the watershed exhibit spatial variability. Air temperatures were influenced by topographic effects such as slope, aspect, and elevation. Rainfall was found to be spatially variable inside the catchment. The impact of this variability on streamflow generation was assessed using a lumped degree-day model. Despite the variability within the watershed, the streamflow discharge could be described using the lumped model. The novelty of this work mainly consists in quantifying spatial variability for a small watershed and showing to which extent this is important. When the focus is on aggregated outputs, such as streamflow discharge, average values of meteorological forcing can be adequately used. On the contrary, when the focus is on distributed fields such as evaporation or soil moisture, their estimate can benefit from distributed measurements.

  17. Monitoring Distributed Snow Cover Characteristics and Snowmelt Energy Balance Terms Before and During Snowmelt Induced Flood Events

    NASA Astrophysics Data System (ADS)

    Pohl, S.; Garvelmann, J.; Weiler, M.

    2013-12-01

    Severe flooding events as a result of rapid snowmelt often enhanced by the occurrence of rain on snow have become a more and more pressing concern for many regions of the world. A reliable forecast of these events relies heavily on an accurate knowledge of the drivers and characteristics (SWE, albedo, surface temperature, amount of snow intercepted in trees) of a mountain snow cover and their spatial pattern ahead of the snowmelt event. Furthermore, the temporal and spatial distribution of the energy fluxes leading to a rapid snowmelt during the event also needs to be understood. The presented study was carried out in the Black Forest region of south-western Germany. We installed a network of 100 standalone snow monitoring stations (SnoMoS) that continuously monitor snow depth and all relevant meteorological variables needed to calculate a full (snow) surface energy balance along with 45 time lapse cameras recording hourly information on several additional snow cover characteristics. The deployment locations were chosen to cover a wide range of elevations and expositions and under a variety of vegetation covers to monitor the influence of vegetation on snow cover evolution and snowmelt energy. Several statistical models were used to spatially analyze and regionalize the snow cover ahead of severe winter floods. This spatially distributed snow cover was then compared against the output from several hydrologic (snow-) model predictions to show strengths and weaknesses of these models. For example, a multiple linear regression approach showed the predictive capability of factors such as elevation, aspect, and land cover and how their respective importance changes over the winter period as a response to snow accumulation and melt cycles. The observation of the climate variables during a melt event gives further insight into how climate variables change over time and space and what regionalization approaches might work best to interpolate climate variables from few

  18. Ecology and Management of the Spring Snowmelt Recession

    NASA Astrophysics Data System (ADS)

    Yarnell, S.; Viers, J. H.; Mount, J. F.

    2009-12-01

    We present a conceptual model for the ecology of the spring snowmelt recession, delineating components of the natural flow regime most relevant to the recession hydrograph and their relation to physical and biological stream processes. Using general principles to describe expected responses in stream ecosystems, we specifically relate the quantifiable components of magnitude, timing and rate of change to abiotic and biotic factors that govern aquatic and riparian ecosystem functioning. We find that shifts in the magnitude of the start of the recession have the largest impacts on abiotic conditions in the channel, while shifts in the timing primarily affect biotic conditions. Shifts in the rate of change of the recession impact both abiotic and biotic conditions, creating the largest observed changes to the stream ecosystem. We discuss these spring hydrograph components with regard to the success of native riverine species, such as cottonwood (Populus spp.) and the Foothill yellow-legged frog (Rana boylii), an indicator species for instream biota in the Mediterranean-montane environment of California. We then present two scenarios of change to the spring snowmelt recession and discuss their potential implications for general stream ecology: 1) effects of flow regulation, and 2) effects of climate warming. Our conceptual model can help guide water resource managers to more effectively maintain key ecosystem processes in regulated rivers, and help watershed stakeholders form adaptation strategies for anticipated changes in the nature of flow regimes due to climate warming.

  19. Hydrologic landscape classification evaluates streamflow vulnerability to climate change in Oregon, USA

    NASA Astrophysics Data System (ADS)

    Leibowitz, S. G.; Comeleo, R. L.; Wigington, P. J., Jr.; Weaver, C. P.; Morefield, P. E.; Sproles, E. A.; Ebersole, J. L.

    2014-09-01

    Classification can allow for evaluations of the hydrologic functions of landscapes and their responses to stressors. Here we demonstrate the use of a hydrologic landscape (HL) approach to evaluate vulnerability to potential future climate change at statewide and basin scales in the state of Oregon. The HL classification has five components: climate, seasonality, aquifer permeability, terrain, and soil permeability. We evaluate changes when the 1971-2000 HL climate indices are recalculated using 2041-2070 simulation results from the ECHAM (European Centre HAMburg) and PCM (Parallel Climate Model) climate models with the A2, A1b, and B1 emission scenarios. Changes in climate class were modest (4-18%) statewide. However, there were major changes in seasonality class for five of the six realizations (excluding PCM_B1): Oregon shifts from being 13% snow-dominated to 4-6% snow-dominated under these five realizations, representing a 56-68% reduction in snowmelt-dominated area. At the basin scale, simulated changes for the Siletz Basin, in Oregon's Coast Range, include a small switch from very wet to wet climate, with no change in seasonality. However, there is a modest increase in fall and winter water due to increased precipitation. For the Sandy Basin, on the western slope of the Cascades, HL climate class does not change, but there are major changes in seasonality, especially for areas with low aquifer permeability, which experiences a 100% loss of spring seasonality. This would reduce summer baseflow, but effects could potentially be mitigated by streamflow buffering effects provided by groundwater in the high aquifer permeability portions of the upper Sandy. The Middle Fork John Day Basin (MFJD), in northeastern Oregon, is snowmelt-dominated. The basin experiences a net loss of wet and moist climate area, along with an increase in dry climate area. The MFJD also experiences major shifts from spring to winter seasonality, representing a 20-60% reduction in snowmelt

  20. Phenology is plastic: the response of alpine shrub Salix herbacea to earlier snowmelt

    NASA Astrophysics Data System (ADS)

    Wheeler, Julia; Sedlacek, Janosch; van Kleunen, Mark; Bossdorf, Oliver; Hoch, Guenter; Wipf, Sonja; Karrenberg, Sophie; Lexer, Christian; Cortés, Andres; Rixen, Christian

    2014-05-01

    Climate change has been demonstrated to accelerate snowmelt in alpine systems, which can represent a critical ecosystem change for alpine plant communities. Understanding how snowmelt timing affects phenology and the development of alpine plants, and the capacity of these plants to respond, is thus necessary for predicting alpine community response to climate change. We examined the effects of snowmelt timing on the phenological development of the common clonal alpine shrub Salix herbacea over three growing seasons using both a space-for-time substitution along a natural snowmelt gradient and a reciprocal transplant experiment of clonal fragments between early and late snowmelt microhabitats. Leaf, flower and fruit development time was significantly influenced by snowmelt timing along both the natural snow gradient and in the reciprocal transplant, with less time required to develop to each phenophase in shrubs growing naturally in late-lying snowbeds and in S. herbacea clonal fragments transplanted from early-exposure sites into late snowbed microhabitats. This suggests that snowmelt timing, likely through the regulation of seasonal temperature accumulation, controls phenological development. In addition, the transplant experiment indicated that S. herbacea demonstrates a highly plastic phenological response to snowmelt timing, because there was no significant difference in phenology between clones originating either from snowbeds or early exposure sites when exposed to the same climatic conditions. Thus, S. herbacea may be able to profit from accelerated snowmelt due to climate change by developing soon after snowmelt. However, freezing damage during vulnerable early development stages may increase, as phenological development is slowed and the probability of lethal freezing events is increased under early snowmelt conditions.

  1. The contribution of glacier melt to streamflow

    SciTech Connect

    Schaner, Neil; Voisin, Nathalie; Nijssen, Bart; Lettenmaier, D. P.

    2012-09-13

    Ongoing and projected future changes in glacier extent and water storage globally have lead to concerns about the implications for water supplies. However, the current magnitude of glacier contributions to river runoff is not well known, nor is the population at risk to future glacier changes. We estimate an upper bound on glacier melt contribution to seasonal streamflow by computing the energy balance of glaciers globally. Melt water quantities are computed as a fraction of total streamflow simulated using a hydrology model and the melt fraction is tracked down the stream network. In general, our estimates of the glacier melt contribution to streamflow are lower than previously published values. Nonetheless, we find that globally an estimated 225 (36) million people live in river basins where maximum seasonal glacier melt contributes at least 10% (25%) of streamflow, mostly in the High Asia region.

  2. Climate change and probabilistic scenario of streamflow extremes in a cryospheric alpine region

    NASA Astrophysics Data System (ADS)

    Yang, Tao; Gao, Cheng

    2015-04-01

    Future projections of streamflow extremes are of paramount significance in assessing the climate impacts on social and natural systems, particularly for the Himalayan alpine region in the Tibetan Plateau known as the Asian Water Tower. This study strives to quantify the uncertainties from different sources in simulating future extreme flows and seeks to construct reliable scenarios of future extreme flows for the headwater catchment of the Yellow River Basin in the 21st century. The results can be formulated as follows: (1) The revised snow model based on a daily active temperature method is superior to the commonly used degree-day method in simulating snowmelt processes. (2) In general, hydrological models contribute more uncertainties than the downscaling methods in high flow and low flow over the cryospheric alpine regions characterized by the snow-rainfall induced runoff processes under most scenarios. Meanwhile, impacts to uncertainty vary with time. (3) The ultimate probability of high-flow exhibits a downward trend in future by using an unconditional method, whereas positive changes in probability of low-flow are projected. The method in the work includes a variety of influence from different contributing factors (e.g. downscaling models, hydrological models, model parameters, and their simulation skills) on streamflow projection, therefore can offer more information (i.e. different percentiles of flow and uncertainty ranges) for future water resources planning compared with the purely deterministic approaches. Hence, the results are beneficial to boost our current methodologies of climate impact research in the Himalayan alpine zone.

  3. Characterizing streamflow generation in Alpine catchments

    NASA Astrophysics Data System (ADS)

    Chiogna, Gabriele; Cano Paoli, Karina; Bellin, Alberto

    2016-04-01

    Developing effective hydrological models for streamflow generation in Alpine catchments is challenging due to the inherent complexity of the intertwined processes controlling water transfer from hillslopes to streams and along the river network. With water discharge as the sole observational variable it is impossible to differentiate between different streamflow sources, and modelling activity is often limited to simplified phenomenological rainfall-runoff models. This study focuses on quantifying streamflow sources at different temporal scales and the associated uncertainty by using natural tracer data (electrical conductivity, oxygen and hydrogen stable isotopes ratios) as observational variables supplementing streamflow measurements. We determine the spatial and temporal hydrological behavior and the mean residence time of water in the Vermigliana catchment, North-Eastern Italy and we separate contributions to streamflow originating from Presena and Presanella glaciers, both exerting a strong control on the hydrologic budget of the study site. Furthermore, we identify a seasonal control on the effect of storm events. The catchment responded rapidly to precipitation events in early autumn, it was unaffected by precipitation events in early spring, while runoff generation was enhanced by snow melting in late autumn. Air temperature is identified as the main controlling parameter, in addition to precipitation. Two-component mixing analysis showed that the relative contribution of new water, which can contribute up to 75% of total streamflow, is very rapid. Only two hours time-lag was observed between the beginning of the precipitation event and the emergence of a significant contribution of new water. These results evidence the relevance of mixing between pre-event and event water in the Vermigliana catchment, and in similar high elevation Alpine catchments. This study provides new insights on the dynamics of streamflow generation in Alpine catchments and a

  4. National Streamflow Information Program: Implementation Status Report

    USGS Publications Warehouse

    Norris, J. Michael

    2009-01-01

    The U.S. Geological Survey (USGS) operates and maintains a nationwide network of about 7,500 streamgages designed to provide and interpret long-term, accurate, and unbiased streamflow information to meet the multiple needs of many diverse national, regional, state, and local users. The National Streamflow Information Program (NSIP) was initiated in 2003 in response to Congressional and stakeholder concerns about (1) the decrease in the number of operating streamgages, including a disproportionate loss of streamgages with a long period of record; (2) the inability of the USGS to continue operating high-priority streamgages in an environment of reduced funding through partnerships; and (3) the increasing demand for streamflow information due to emerging resource-management issues and new data-delivery capabilities. The NSIP's mission is to provide the streamflow information and understanding required to meet national, regional, state, and local needs. Most of the existing streamgages are funded through partnerships with more than 850 other Federal, state, tribal, and local agencies. Currently, about 90 percent of the streamgages send data to the World Wide Web in near-real time (some information is transmitted within 15 minutes, whereas some lags by about 4 hours). The streamflow information collected at USGS streamgages is used for many purposes: *In water-resource appraisals and allocations - to determine how much water is available and how it is being allocated; *To provide streamflow information required by interstate agreements, compacts, and court decrees; *For engineering design of reservoirs, bridges, roads, culverts, and treatment plants; *For the operation of reservoirs, the operation of locks and dams for navigation purposes, and power production; *To identify changes in streamflow resulting from changes in land use, water use, and climate; *For streamflow forecasting, flood planning, and flood forecasting; *To support water-quality programs by allowing

  5. A proposed streamflow data program for Oklahoma

    USGS Publications Warehouse

    Bohn, J.D.; Hoffman, G.L.

    1970-01-01

    An evaluation of the streamflow data available in Oklahoma has been made to provide guidelines for planning future data-collection programs. The basic steps in the evaluation procedure were (1) definition of the long-terms goals of the streamflow-data program in quantitative form, (2) examination and analysis of streamflow data to determine which goals have been met, and (3) consideration of alternate programs and techniques to meet the remaining goals. The study defines the individual relation between certain statistical streamflow characteristics and selected basin parameters. This relation is a multiple regression equation that could be used on a statewide basis to compute a selected natural-flow characteristic at any site on a stream. The study shows that several streamflow characteristics can be estimated within an accuracy equivalent to 10 years of record by use of a regression related to at least three climatic or basin parameters for any basin of 50 square miles or more. The study indicates that significant changes in the scope and character of the data-collection program would enhance the possibility of attaining the remaining goals. A streamflow-data program based on the guidelines developed in this study is proposed for the future.

  6. Precipitation-runoff processes in the Feather River basin, northeastern California, and streamflow predictability, water years 1971-97

    USGS Publications Warehouse

    Koczot, Kathryn M.; Jeton, Anne E.; McGurk, Bruce; Dettinger, Michael D.

    2005-01-01

    -shadowed basins of the northeastern Sierra Nevada than the uplands of most western Sierra Nevada river basins. The climate is mediterranean, with most of the annual precipitation occurring in winter. Because the basin includes large areas that are near the average snowline, rainfall and rain-snow mixtures are common during winter storms. Consequently, the overall timing and rates of runoff from the basin are highly sensitive to winter temperature fluctuations. The models were developed to simulate runoff-generating processes in eight drainages of the Feather River Basin. Together, these models simulate streamflow from 98 percent of the basin above Lake Oroville. The models simulate daily water and heat balances, snowpack evolution and snowmelt, evaporation and transpiration, subsurface water storage and outflows, and streamflow to key streamflow gage sites. The drainages are modeled as 324 hydrologic-response units, each of which is assumed homogeneous in physical characteristics and response to precipitation and runoff. The models were calibrated with emphasis on reproducing monthly streamflow rates, and model simulations were compared to the total natural inflows into Lake Oroville as reconstructed by the California Department of Water Resources for April-July snowmelt seasons from 1971 to 1997. The models are most sensitive to input values and patterns of precipitation and soil characteristics. The input precipitation values were allowed to vary on a daily basis to reflect available observations by making daily transformations to an existing map of long-term mean monthly precipitation rates that account for altitude and rain-shadow effects. The models effectively simulate streamflow into Lake Oroville during water years (October through September) 1971-97, which is demonstrated in hydrographs and statistical results presented in this report. The Butt Creek model yields the most accurate historical April-July simulations, whereas the West Branch

  7. Estimating Watershed-Averaged Precipitation and Evapotranspiration Fluxes using Streamflow Measurements in a Semi-Arid, High Altitude Montane Catchment

    NASA Astrophysics Data System (ADS)

    Herrington, C.; Gonzalez-Pinzon, R.

    2014-12-01

    Streamflow through the Middle Rio Grande Valley is largely driven by snowmelt pulses and monsoonal precipitation events originating in the mountain highlands of New Mexico (NM) and Colorado. Water managers rely on results from storage/runoff models to distribute this resource statewide and to allocate compact deliveries to Texas under the Rio Grande Compact agreement. Prevalent drought conditions and the added uncertainty of climate change effects in the American southwest have led to a greater call for accuracy in storage model parameter inputs. While precipitation and evapotranspiration measurements are subject to scaling and representativeness errors, streamflow readings remain relatively dependable and allow watershed-average water budget estimates. Our study seeks to show that by "Doing Hydrology Backwards" we can effectively estimate watershed-average precipitation and evapotranspiration fluxes in semi-arid landscapes of NM using fluctuations in streamflow data alone. We tested this method in the Valles Caldera National Preserve (VCNP) in the Jemez Mountains of central NM. This method will be further verified by using existing weather stations and eddy-covariance towers within the VCNP to obtain measured values to compare against our model results. This study contributes to further validate this technique as being successful in humid and semi-arid catchments as the method has already been verified as effective in the former setting.

  8. Role of climate forecasts and initial land-surface conditions in developing operational streamflow and soil moisture forecasts in a rainfall-runoff regime: skill assessment

    NASA Astrophysics Data System (ADS)

    Sinha, T.; Sankarasubramanian, A.

    2012-04-01

    Skillful seasonal streamflow forecasts obtained from climate and land surface conditions could significantly improve water and energy management. Since climate forecasts are updated on monthly basis, we evaluate the potential in developing operational monthly streamflow forecasts on a continuous basis throughout the year. Further, basins in the rainfall-runoff regime critically depend on the forecasted precipitation in the upcoming months as opposed to snowmelt regimes where initial hydrological conditions (IHC) play a critical role. The goal of this study is to quantify the role of monthly updated precipitation forecasts and IHC in forecasting 6-month lead monthly streamflow for a rainfall-runoff mechanism dominated basin - Apalachicola River at Chattahoochee, FL. The Variable Infiltration Capacity (VIC) land surface model is implemented with two forcings: (a) monthly updated precipitation forecasts from ECHAM4.5 Atmospheric General Circulation Model (AGCM) forced with sea surface temperature forecasts and (b) daily climatological ensemble. The difference in skill between the above two quantifies the improvements that could be attainable using the AGCM forecasts. Monthly retrospective streamflow forecasts are developed from 1981 to 2010 and streamflow forecasts estimated from the VIC model are also compared with those predicted by using the principal component regression (PCR) model. Mean square error (MSE) in predicting monthly streamflow using the above VIC model are compared with the MSE of streamflow climatology under ENSO conditions as well as under normal years. Results indicate that VIC forecasts, at 1-2 month lead time, obtained using ECHAM4.5 are significantly better than VIC forecasts obtained using climatological ensemble over all the seasons except forecasts issued in fall and the PCR models perform better during the fall months. Over longer lead times (3-6 months), VIC forecasts derived using ECHAM4.5 forcings alone performed better compared to the

  9. The sensitivity of snowmelt processes to meterological conditions and forest cover during rain-on-snow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Devastating floods in the intermountain western US can result from rapid snowmelt during mid-winter rain-on-snow (ROS) events. Key components of snowmelt flooding during ROS are conditions prior to the storm, the combination of temperature, humidity and wind during the event, and the extent to which...

  10. Glacier contribution to streamflow in two headwaters of the Huasco River, Dry Andes of Chile

    NASA Astrophysics Data System (ADS)

    Gascoin, S.; Kinnard, C.; Ponce, R.; Lhermitte, S.; MacDonell, S.; Rabatel, A.

    2011-12-01

    Quantitative assessment of glacier contribution to present-day streamflow is a prerequisite to the anticipation of climate change impact on water resources in the Dry Andes. In this paper we focus on two glaciated headwater catchments of the Huasco Basin (Chile, 29° S). The combination of glacier monitoring data for five glaciers (Toro 1, Toro 2, Esperanza, Guanaco, Estrecho and Ortigas) with five automatic streamflow records at sites with glacier coverage of 0.4 to 11 % allows the estimation of the mean annual glacier contribution to discharge between 2003/2004 and 2007/2008 hydrological years. In addition, direct manual measurements of glacier runoff were conducted in summer at the snouts of four glaciers, which provide the instantaneous contribution of glacier meltwater to stream runoff during summer. The results show that the mean annual glacier contribution to streamflow ranges between 3.3 and 23 %, which is greater than the glaciated fraction of the catchments. We argue that glacier contribution is partly enhanced by the effect of snowdrift from the non-glacier area to the glacier surface. Glacier mass loss is evident over the study period, with a mean of -0.84 m w.e. yr-1 for the period 2003/2004-2007/2008, and also contributes to increase glacier runoff. An El Niño episode in 2002 resulted in high snow accumulation, modifying the hydrological regime and probably reducing the glacier contribution in favor of seasonal snowmelt during the subsequent 2002/2003 hydrological year. At the hourly timescale, summertime glacier contributions are highly variable in space and time, revealing large differences in effective melting rates between glaciers and glacierets (from 1 mm w.e. h-1 to 6 mm w.e. h-1).

  11. Detection, attribution, and sensitivity of trends toward earlier streamflow in the Sierra Nevada

    USGS Publications Warehouse

    Maurer, E.P.; Stewart, I.T.; Bonfils, Celine; Duffy, P.B.; Cayan, D.

    2007-01-01

    Observed changes in the timing of snowmelt dominated streamflow in the western United States are often linked to anthropogenic or other external causes. We assess whether observed streamflow timing changes can be statistically attributed to external forcing, or whether they still lie within the bounds of natural (internal) variability for four large Sierra Nevada (CA) basins, at inflow points to major reservoirs. Streamflow timing is measured by "center timing" (CT), the day when half the annual flow has passed a given point. We use a physically based hydrology model driven by meteorological input from a global climate model to quantify the natural variability in CT trends. Estimated 50-year trends in CT due to natural climate variability often exceed estimated actual CT trends from 1950 to 1999. Thus, although observed trends in CT to date may be statistically significant, they cannot yet be statistically attributed to external influences on climate. We estimate that projected CT changes at the four major reservoir inflows will, with 90% confidence, exceed those from natural variability within 1-4 decades or 4-8 decades, depending on rates of future greenhouse gas emissions. To identify areas most likely to exhibit CT changes in response to rising temperatures, we calculate changes in CT under temperature increases from 1 to 5??. We find that areas with average winter temperatures between -2??C and -4??C are most likely to respond with significant CT shifts. Correspondingly, elevations from 2000 to 2800 in are most sensitive to temperature increases, with CT changes exceeding 45 days (earlier) relative to 1961-1990. Copyright 2007 by the American Geophysical Union.

  12. Clouds and snowmelt on the north slope of Alaska

    SciTech Connect

    Zhang, T.; Stamnes, K.; Bowling, S.A.

    1996-04-01

    Clouds have a large effect on the radiation field. Consequently, possible changes in cloud properties may have a very substantial impact on climate. Of all natural surfaces, seasonal snow cover has the highest surface albedo, which is one of the most important components of the climatic system. Interactions between clouds and seasonal snow cover are expected to have a significant effect on climate and its change at high latitudes. The purpose of this paper is to investigate the sensitivity of the surface cloud-radiative forcing during the period of snowmelt at high latitudes. The primary variables investigated are cloud liquid path (LWP) and droplet equivalent radius (r{sub e}). We will also examine the sensitivity of the surface radiative fluxes to cloud base height and cloud base temperature.

  13. Ecohydrological response to snowmelt dynamics from plot to regional scales

    NASA Astrophysics Data System (ADS)

    Molotch, N. P.; Musselman, K. N.; Trujillo, E.; Brooks, P. D.; McConnell, J. R.; Williams, M. W.

    2010-12-01

    New remote sensing and in situ measurement capabilities afford improved understanding of distributed ecohydrological processes in mountainous regions. In this regard, distributed ecohydrologic instrument clusters allow us to observe micro-scale variability in snow-vegetation interactions while remotely sensed data allow us to observe integrated ecosystem-scale response to snow-water availability. Instrument clusters deployed in the Central and Southern Rockies and the Sierra Nevada reveal the dominant role of vegetation in controlling the timing and magnitude of snow accumulation and snowmelt. In this regard, vegetation structure largely controlled the distribution of snow accumulation with 29% greater accumulation in open versus under-canopy locations. Snow ablation rates were diminished by 39% in under-canopy locations. Similarly, differences in climate altered snow-season duration, snowmelt infiltration and evapotranspiration. Commencement of the growing season was coincident with melt-water input to the soil and lagged behind springtime increases in air temperature by several days. Similarly, the timing of peak soil moisture was highly dependent upon snow ablation, occurring within one week of snow disappearance on average. Analysis of remotely sensed vegetation greenness data at the regional scale reveals a coherent signal with regard to these plot-scale measurements. A strong elevational dependence in the relationships between snow disappearance timing and peak vegetation greenness are evident whereby vegetation greenness is highly sensitive to inter-annual variability in snow disappearance timing at low - mid elevations whereas higher elevation forest greenness was relatively insensitive. These elevational variations suggest a switch from water limitations at the lower elevation to energy limitations at the highest elevations. Given potential future changes in the hydroclimatology of mountainous regions, the results of these multi-scale measurements may

  14. Energy budget increases reduce mean streamflow more than snow–rain transitions: using integrated modeling to isolate climate change impacts on Rocky Mountain hydrology

    NASA Astrophysics Data System (ADS)

    Foster, Lauren M.; Bearup, Lindsay A.; Molotch, Noah P.; Brooks, Paul D.; Maxwell, Reed M.

    2016-04-01

    In snow-dominated mountain regions, a warming climate is expected to alter two drivers of hydrology: (1) decrease the fraction of precipitation falling as snow; and (2) increase surface energy available to drive evapotranspiration. This study uses a novel integrated modeling approach to explicitly separate energy budget increases via warming from precipitation phase transitions from snow to rain in two mountain headwaters transects of the central Rocky Mountains. Both phase transitions and energy increases had significant, though unique, impacts on semi-arid mountain hydrology in our simulations. A complete shift in precipitation from snow to rain reduced streamflow between 11% and 18%, while 4 °C of uniform warming reduced streamflow between 19% and 23%, suggesting that changes in energy-driven evaporative loss, between 27% and 29% for these uniform warming scenarios, may be the dominant driver of annual mean streamflow in a warming climate. Phase changes induced a flashier system, making water availability more susceptible to precipitation variability and eliminating the runoff signature characteristic of snowmelt-dominated systems. The impact of a phase change on mean streamflow was reduced as aridity increased from west to east of the continental divide.

  15. Effects of the El Niño-southern oscillation on temperature, precipitation, snow water equivalent and resulting streamflow in the Upper Rio Grande river basin

    NASA Astrophysics Data System (ADS)

    Lee, Songweon; Klein, Andrew; Over, Thomas

    2004-04-01

    Snowmelt runoff dominates streamflow in the Upper Rio Grande (URG) basin of New Mexico and Colorado. Annual variations in streamflow timing and volume at most stations in the region are strongly influenced by the El Niño-southern oscillation (ENSO) through its modulation of the seasonal cycles of temperature and precipitation, and hence on snow accumulation and melting. After removing long-term trends over the study period (water years 1952-99), the dependence of monthly temperature, precipitation, snow water equivalent (SWE) at snowcourse stations, and streamflow throughout the URG on ENSO was investigated using composite analyses of the detrended residuals and through dependence of the residuals on the Climate Prediction Center southern oscillation index during the preceding summer and fall. The climate of La Niña years was found to differ significantly from either El Niño or neutral years. Moreover, significant climatological ENSO-related effects are confined to certain months, predominantly at the beginning and end of the winter season. In particular, March of La Niña years is significantly warmer and drier than during either El Niño or neutral years, and November of El Niño years is significantly colder and wetter. Differences in temperature and precipitation lead to significant differences in SWE and streamflow in the URG between the three ENSO phases.

  16. Explaining streamflow variability of the Gila and Rio Grande rivers : Pacific teleconnections and catchment-scale interaction of the hydrological cycle with vegetation and soil moisture

    NASA Astrophysics Data System (ADS)

    Pascolini-Campbell, M.; Seager, R.

    2015-12-01

    The streamflows of the Gila River, N.M. and the upper Rio Grande, with headwaters in Colorado are influenced by a range of drivers including the El Nino-Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO) and, for the Gila, the North American Monsoon. At the catchment scale, runoff to the river is modulated by the interaction of snowmelt, rainfall, evapotranspiration, soil moisture and vegetation. A simple eco-hydological model is used to explain the seasonal cycles of flow of the Gila (strong spring peak, weak summer peak) and upper Rio Grande (single spring peak) in terms of precipitation, snowpack, and evapotranspiration. We then examine the drivers of streamflow variability using USGS gages located upstream of human extraction, precipitation and temperature data from PRISM, and SST data from ERSST. High spring streamflow tends to occur in response to prior winter El Nino but not all high and low streamflow events can be explained by the Pacific teleconnection. Decadal variations, including low flows in the Gila and upper Rio Grande since the mid 1990s, are explained in terms of the Pacific and Atlantic Ocean decadal variability.

  17. Using the snowmelt runoff model to evaluate climate change effects and to compare basin runoff between New Mexico and Idaho.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Snowmelt Runoff Model(SRM) has been developed and tested in small to large basins worldwide. SRM has been found to be very useful for understanding snowmelt processes as well as for simulating or forecasting snowmelt-derived water supplies. SRM is being used in New Mexico in a NSF-funded EPSCo...

  18. Multivariate streamflow forecasting using independent component analysis

    NASA Astrophysics Data System (ADS)

    Westra, Seth; Sharma, Ashish; Brown, Casey; Lall, Upmanu

    2008-02-01

    Seasonal forecasting of streamflow provides many benefits to society, by improving our ability to plan and adapt to changing water supplies. A common approach to developing these forecasts is to use statistical methods that link a set of predictors representing climate state as it relates to historical streamflow, and then using this model to project streamflow one or more seasons in advance based on current or a projected climate state. We present an approach for forecasting multivariate time series using independent component analysis (ICA) to transform the multivariate data to a set of univariate time series that are mutually independent, thereby allowing for the much broader class of univariate models to provide seasonal forecasts for each transformed series. Uncertainty is incorporated by bootstrapping the error component of each univariate model so that the probability distribution of the errors is maintained. Although all analyses are performed on univariate time series, the spatial dependence of the streamflow is captured by applying the inverse ICA transform to the predicted univariate series. We demonstrate the technique on a multivariate streamflow data set in Colombia, South America, by comparing the results to a range of other commonly used forecasting methods. The results show that the ICA-based technique is significantly better at representing spatial dependence, while not resulting in any loss of ability in capturing temporal dependence. As such, the ICA-based technique would be expected to yield considerable advantages when used in a probabilistic setting to manage large reservoir systems with multiple inflows or data collection points.

  19. Water quality, streamflow conditions, and annual flow-duration curves for streams of the San Juan–Chama Project, southern Colorado and northern New Mexico, 1935-2010

    USGS Publications Warehouse

    Falk, Sarah E.; Anderholm, Scott K.; Hafich, Katya A.

    2013-01-01

    , Horse Lake Creek, and Willow Creek watersheds, which are underlain mostly by Cretaceous-aged marine shale, was compositionally similar and had large concentrations of sulfate relative to the other streams in the study area, though the water from the Navajo River had lower specific-conductance values than did the water from Horse Lake Creek above Heron Reservoir and Willow Creek above Azotea Creek. Generally, surface-water quality varied with streamflow conditions throughout the year. Streamflow in spring and summer is generally a mixture of base flow (the component of streamflow derived from groundwater discharged to the stream channel) diluted with runoff from snowmelt and precipitation events, whereas streamflow in fall and winter is generally solely base flow. Major- and trace-element concentrations in the streams sampled were lower than U.S. Environmental Protection Agency primary and secondary drinking-water standards and New Mexico Environment Department surface-water standards for the streams. In general, years with increased annual discharge, compared to years with decreased annual discharge, had a smaller percentage of discharge in March, a larger percentage of discharge in June, an interval of discharge derived from snowmelt runoff that occurred later in the year, and a larger discharge in June. Additionally, years with increased annual discharge generally had a longer duration of runoff, and the streamflow indicators occurred at dates later in the year than the years with less snowmelt runoff. Additionally, the seasonal distribution of streamflow was more strongly controlled by the change in the amount of annual discharge than by changes in streamflow over time. The variation of streamflow conditions over time at one streamflow-gaging station in the study area, Navajo River at Banded Peak Ranch, was not significantly monotonic over the period of record with a Kendall’s tau of 0.0426 and with a p-value of 0.5938 for 1937 to 2009 (a trend was considered

  20. Deciduous trees are a large and overlooked sink for snowmelt water in the boreal forest

    PubMed Central

    Young-Robertson, Jessica M.; Bolton, W. Robert; Bhatt, Uma S.; Cristóbal, Jordi; Thoman, Richard

    2016-01-01

    The terrestrial water cycle contains large uncertainties that impact our understanding of water budgets and climate dynamics. Water storage is a key uncertainty in the boreal water budget, with tree water storage often ignored. The goal of this study is to quantify tree water content during the snowmelt and growing season periods for Alaskan and western Canadian boreal forests. Deciduous trees reached saturation between snowmelt and leaf-out, taking up 21–25% of the available snowmelt water, while coniferous trees removed <1%. We found that deciduous trees removed 17.8–20.9 billion m3 of snowmelt water, which is equivalent to 8.7–10.2% of the Yukon River’s annual discharge. Deciduous trees transpired 2–12% (0.4–2.2 billion m3) of the absorbed snowmelt water immediately after leaf-out, increasing favorable conditions for atmospheric convection, and an additional 10–30% (2.0–5.2 billion m3) between leaf-out and mid-summer. By 2100, boreal deciduous tree area is expected to increase by 1–15%, potentially resulting in an additional 0.3–3 billion m3 of snowmelt water removed from the soil per year. This study is the first to show that deciduous tree water uptake of snowmelt water represents a large but overlooked aspect of the water balance in boreal watersheds. PMID:27404274

  1. Deciduous trees are a large and overlooked sink for snowmelt water in the boreal forest

    NASA Astrophysics Data System (ADS)

    Young-Robertson, Jessica M.; Bolton, W. Robert; Bhatt, Uma S.; Cristóbal, Jordi; Thoman, Richard

    2016-07-01

    The terrestrial water cycle contains large uncertainties that impact our understanding of water budgets and climate dynamics. Water storage is a key uncertainty in the boreal water budget, with tree water storage often ignored. The goal of this study is to quantify tree water content during the snowmelt and growing season periods for Alaskan and western Canadian boreal forests. Deciduous trees reached saturation between snowmelt and leaf-out, taking up 21–25% of the available snowmelt water, while coniferous trees removed <1%. We found that deciduous trees removed 17.8–20.9 billion m3 of snowmelt water, which is equivalent to 8.7–10.2% of the Yukon River’s annual discharge. Deciduous trees transpired 2–12% (0.4–2.2 billion m3) of the absorbed snowmelt water immediately after leaf-out, increasing favorable conditions for atmospheric convection, and an additional 10–30% (2.0–5.2 billion m3) between leaf-out and mid-summer. By 2100, boreal deciduous tree area is expected to increase by 1–15%, potentially resulting in an additional 0.3–3 billion m3 of snowmelt water removed from the soil per year. This study is the first to show that deciduous tree water uptake of snowmelt water represents a large but overlooked aspect of the water balance in boreal watersheds.

  2. Deciduous trees are a large and overlooked sink for snowmelt water in the boreal forest.

    PubMed

    Young-Robertson, Jessica M; Bolton, W Robert; Bhatt, Uma S; Cristóbal, Jordi; Thoman, Richard

    2016-01-01

    The terrestrial water cycle contains large uncertainties that impact our understanding of water budgets and climate dynamics. Water storage is a key uncertainty in the boreal water budget, with tree water storage often ignored. The goal of this study is to quantify tree water content during the snowmelt and growing season periods for Alaskan and western Canadian boreal forests. Deciduous trees reached saturation between snowmelt and leaf-out, taking up 21-25% of the available snowmelt water, while coniferous trees removed <1%. We found that deciduous trees removed 17.8-20.9 billion m(3) of snowmelt water, which is equivalent to 8.7-10.2% of the Yukon River's annual discharge. Deciduous trees transpired 2-12% (0.4-2.2 billion m(3)) of the absorbed snowmelt water immediately after leaf-out, increasing favorable conditions for atmospheric convection, and an additional 10-30% (2.0-5.2 billion m(3)) between leaf-out and mid-summer. By 2100, boreal deciduous tree area is expected to increase by 1-15%, potentially resulting in an additional 0.3-3 billion m(3) of snowmelt water removed from the soil per year. This study is the first to show that deciduous tree water uptake of snowmelt water represents a large but overlooked aspect of the water balance in boreal watersheds. PMID:27404274

  3. Impact of clouds on surface radiative fluxes and snowmelt in the Arctic and subarctic

    SciTech Connect

    Zhang, T.; Stamnes, K.; Bowling, S.A.

    1996-09-01

    A comprehensive atmospheric radiative transfer model combined with the surface energy balance equation is applied to investigate the impact of clouds on surface radiative fluxes and snowmelt in the Arctic and subarctic. Results show that at the surface, the shortwave cloud-radiative forcing is negative, while the longwave forcing is positive and generally much larger than the shortwave forcing. Thus, the all-wave surface cloud-radiative forcing is positive, with clouds warming the lower atmosphere and enhancing snowmelt during the melting period in the Arctic and subarctic. These results agree with and explain observations and measurements over the past three decades showing that the onset of snowmelt starts earlier under cloudy sky conditions than under clear sky conditions in the Arctic. Clouds could change the date of onset of onset of snowmelt by as much as a month, which is of the order of the observed interannual variations in the timing of snowmelt by as much as a month, which is of the order of the observed interannual variations in the timing of snowmelt in the Arctic and subarctic. The all-wave cloud radiative forcing during the period of snowmelt reaches a maximum at equivalent cloud droplet radius (r{sub e}) of about 9 {mu}m, and cloud liquid water path of about 29 g m{sup {minus}2}. For thin clouds, the impact of changes in liquid water path on all-wave cloud radiative forcing is greater than changes in equivalent cloud droplet size, while for thick clouds, the equivalent cloud droplet size becomes more important. Cloud-base temperature and to a minor extent cloud-base height also influence the surface radiative fluxes and snowmelt. This study indicates that the coupling between clouds and snowmelt could amplify the climate perturbation in the Arctic. 28 refs., 14 figs., 1 tab.

  4. Streamflow Statistics for the Narraguagus River at Cherryfield, Maine

    USGS Publications Warehouse

    Dudley, Robert W.; Nielsen, Joseph P.

    2000-01-01

    Streamflow data have been collected for the Narraguagus River from 1948 to the present (2000) at the U.S. Geological Survey (USGS) streamgaging station at Cherryfield, Maine. This report describes a study done by the USGS to determine streamflow statistics using the streamflow record at the Narraguagus River station for use in total water use management plans implemented by State and Federal agencies. Because the effect of changes in irrigation practices from 1993 to the present on streamflow in the Narraguagus basin is unknown and potentially significant, streamflow data after December 1992 were not used in the determination of the streamflow statistics. For the period 1948- 92, monthly median streamflows range from 93.0 ft3/s (August) to 1,000 ft3/s (April). The median streamflow for the selected period of record for all days (1948-92) is 302 ft3/s.

  5. How does spatial variability of climate affect catchment streamflow predictions?

    EPA Science Inventory

    Spatial variability of climate can negatively affect catchment streamflow predictions if it is not explicitly accounted for in hydrologic models. In this paper, we examine the changes in streamflow predictability when a hydrologic model is run with spatially variable (distribute...

  6. Effect of Reindeer Grazing on Snowmelt, Albedo and Energy Balance Based on Satellite Data Analysis

    NASA Astrophysics Data System (ADS)

    Cohen, Juval; Pulliainen, Jouni; Ménard, Cécile; Johansen, Bernt; Oksanen, Lauri; Luojus, Kari; Ikonen, Jaakko

    2013-04-01

    Surface albedo has a major influence on the energy balance of the Earth. The albedo difference between snow-covered and snow-free tundra is very significant. Therefore, a delay in the snowmelt will decrease the absorbed solar energy on the ground. Earlier studies have shown that higher and denser vegetation causes earlier snowmelt, and that shrub height and abundance, as well as the total biomass in summer reindeer pastures is lower than in winter pastures. The possibility of using reindeer summer grazing to decrease the vegetation, delay the snowmelt and decrease the ground heating during the snowmelt season is investigated in this study. Satellite data is used to compare between summer and non-summer grazing areas in the northern tundra areas of Fennoscandia. A comparison of vegetation types, NDVI, fractional snow cover and albedo between the Finnish year-round pastures and the Norwegian non-summer pastures is performed. Other factors influencing the snowmelt, such as surface temperature, ground elevation and incoming solar radiation are taken into account. Information about the vegetation on the ground is based on a vegetation map compiled from Landsat TM/ETM+ satellite data and ancillary map information. The NDVI, snowmelt and albedo analyses are performed using multi-temporal remote sensing data such as GlobSnow SE and MODIS based NDVI, snow and albedo products. The results here support previous studies and indicate that vegetation in the summer pastures is shorter and sparser and that the snowmelt there occurs later than in the more densely vegetated, non-summer pastures. More shrubs protruding above the snowpack and earlier snowmelt on the Norwegian side lower the albedo during the snowmelt season. This causes higher solar energy absorption of up to 6 W/m2 in the snowmelt season and yearly contribution of up to 0.5 W/m2 to the yearly energy balance. Therefore this study suggests that summer reindeer herding can be used to delay snowmelt, increase surface

  7. Problems of snowmelt runoff modelling for a variety of physiographic and climatic conditions

    USGS Publications Warehouse

    Leavesley, G.H.

    1989-01-01

    Problems include: a) definition of the spatial and temporal distribution of model input; b) measurement or estimation of snow accumulation, snowmelt, and runoff process parameters for a range of applications and scales; and c) development of accurate short term and long term snowmelt runoff forecasts. Procedures being investigated to solve these problems include: a) integrating conventional and remote-sensing data to improve estimates of input data; b) developing snowmelt process algorithms which have parameters that are closely related to measurable basin and climatic characteristics; and c) updating model paramters and components using measured data or knowledge of past uncertainty. -from Author

  8. Proposed hydrologic analyses of streamflow for Brazil

    USGS Publications Warehouse

    Riggs, Henry Chiles

    1974-01-01

    Streamflow records are evaluated for the Rio Jacui basin in the state of Rio Grande Sul, Brazil, in reference to data reliability, length of record, and density of areal coverage. Availability of water is a factor in the development of a country, and surface water is of especial importance in Brazil. This report is intended as a reference for further investigation of the flow characteristic of the basin to provide (1) information for utilization of streamflow and (2) information to improve the data collection and analytic procedures. In addition the evaluation study can serve as a pilot for other developing river basins in Brazil. (Woodard-USGS)

  9. Response of streamflow to multiple earthquakes

    SciTech Connect

    Manga, Michael; Brodsky, Emily E.; Boone, Michael

    2002-06-01

    We analyze the streamflow response of Sespe Creek, CA, to several large earthquakes. We find that flow increased after three earthquakes, and that the observed changes in flow have the same character. Both those earthquakes that induced static extension and those that induced static contraction cause flow to increase; streamflow thus appears to respond to dynamic strain. We find that all postseismic responses can be explained by a model in which pore pressure increases coseismically without any changes in hydraulic diffusivity. There is a particle velocity threshold in the range of 5-20 cm/s to induce the pore pressure increase. [References: 16

  10. Evaluation of the flood hydrology in the Colorado Front Range using precipitation, streamflow, and paleoflood data for the Big Thompson River basin

    USGS Publications Warehouse

    Jarrett, R.D.; Costa, J.E.

    1988-01-01

    A multidisciplinary study of precipitation and streamflow data and paleohydrologic studies of channel features was made to analyze the flood hydrology of foothill and mountain streams in the Front Range of Colorado, with emphasis on the Big Thompson River basin, because conventional hydrologic analyses do not adequately characterize the flood hydrology. In the foothills of Colorado, annual floodflows are derived from snowmelt at high elevations in the mountain regions, from rainfall at low elevation in the plains or plateau regions, or from a combination of rain falling on snow or mixed population hydrology. Above approximately 7,500 ft, snowmelt dominates; rain does not contribute to the flood potential. Regional flood-frequency relations were developed and compared with conventional flood-estimating technique results, including an evaluation of the magnitude and frequency of the probable maximum flood. Evaluation of streamflow data and paleoflood investigations provide an alternative for evaluating flood hydrology and the safety of dams. The study indicates the need for additional data collection and research to understand the complexities of the flood hydrology in mountainous regions, especially its effects on flood-plain management and the design of structures in the flood plain. (USGS)

  11. Modeling the influence of hypsometry, vegetation, and storm energy on snowmelt contributions to basins during rain-on-snow floods

    NASA Astrophysics Data System (ADS)

    Wayand, Nicholas E.; Lundquist, Jessica D.; Clark, Martyn P.

    2015-10-01

    Point observations and previous basin modeling efforts have suggested that snowmelt may be a significant input of water for runoff during extreme rain-on-snow floods within western U.S. basins. Quantifying snowmelt input over entire basins is difficult given sparse observations of snowmelt. In order to provide a range of snowmelt contributions for water managers, a physically based snow model coupled with an idealized basin representation was evaluated in point simulations and used to quantify the maximum basin-wide input from snowmelt volume during flood events. Maximum snowmelt basin contributions and uncertainty ranges were estimated as 29% (11-47%), 29% (8-37%), and 7% (2-24%) of total rain plus snowmelt input, within the Snoqualmie, East North Fork Feather, and Upper San Joaquin basins, respectively, during historic flooding events between 1980 and 2008. The idealized basin representation revealed that both hypsometry and forest cover of a basin had similar magnitude of impacts on the basin-wide snowmelt totals. However, the characteristics of a given storm (antecedent SWE and available energy for melt) controlled how much hypsometry and forest cover impacted basin-wide snowmelt. These results indicate that for watershed managers, flood forecasting efforts should prioritize rainfall prediction first, but cannot neglect snowmelt contributions in some cases. Efforts to reduce the uncertainty in the above snowmelt simulations should focus on improving the meteorological forcing data (especially air temperature and wind speed) in complex terrain.

  12. Assessing the Vulnerability of Water Supply to Changing Streamflow Conditions

    NASA Astrophysics Data System (ADS)

    Nazemi, Alireza (Ali); Wheater, Howard S.

    2014-08-01

    Natural streamflows are major water supplies globally and are sensitive to climate change. This has serious implications for water resource management: While changes in climate perturb water availability, human activities are developed around certain streamflow characteristics, such as flow seasonality and volume. Therefore, any shifts in streamflow regime can greatly affect human livelihoods.

  13. National streamflow trends and development of hydrologic change indicators for surface-water resources of the United States

    NASA Astrophysics Data System (ADS)

    Dudley, R. W.; McHale, M. R.; Hodgkins, G. A.; McCabe, G. J.; Wolock, D.

    2011-12-01

    Over the past century, annual air temperatures and precipitation have increased in large parts of the United States. Coincident with precipitation increases, analysis of 30-80 years of streamflow-gaging data across the U.S. generally shows significantly increasing minimum and median flows that appear to have happened as a step change around 1970. For areas of the country that have a substantial amount of annual precipitation stored in winter snowpack, significant changes toward earlier snowmelt runoff during the last 50 years have been documented in areas sensitive to changes in winter and spring air temperatures. In Alaskan basins having substantial glacier-covered area, warming has increased annual peak flows and monthly flows during winter, spring, and summer. The wide variety of terrain and range in latitude in the U.S. contributes to substantially different climates in the country with regional climate influenced by ocean circulation, weather patterns, and other factors. Some hydrologic variables provide relevant information at the national level, such as annual peak streamflows, and others are relevant only to certain regions of the country, such as metrics of snowmelt runoff timing. This study develops a set of national-scale hydrologic-change indicator variables useful for measuring the effects of climatic changes on surface-water resources of the U.S. While development of these indicators necessarily addresses the variation in climate throughout the U.S., they also were developed to be easily understandable and therefore easily communicated to non-scientists. Further, the indicators are derived from readily available, reliable, and consistent data that could be easily revisited to provide regular updating for long-term analysis and to place contemporary trends in historical context.

  14. Determination of Curve Number for snowmelt-runoff floods in a small catchment

    NASA Astrophysics Data System (ADS)

    Hejduk, L.; Hejduk, A.; Banasik, K.

    2015-06-01

    One of the widely used methods for predicting flood runoff depth from ungauged catchments is the curve number (CN) method, developed by Soil Conservation Service (SCS) of US Department of Agriculture. The CN parameter can be computed directly from recorded rainfall depths and direct runoff volumes in case of existing data. In presented investigations, the CN parameter has been computed for snowmelt-runoff events based on snowmelt and rainfall measurements. All required data has been gathered for a small agricultural catchment (A = 23.4 km2) of Zagożdżonka river, located in Central Poland. The CN number received from 28 snowmelt-runoff events has been compared with CN computed from rainfall-runoff events for the same catchment. The CN parameter, estimated empirically varies from 64.0 to 94.8. The relation between CN and snowmelt depth was investigated in a similar procedure to relation between CN and rainfall depth.

  15. Seasonal and daily snowmelt runoff estimates utilizing satellite data. [Wind River Mountains, Wyoming

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Methods using snowcovered area to update seasonal forecasts as snowmelt progresses are also being used in quasi-operational situations. The input of snowcovered area to snowmelt models for short term perdictions was attempted in two ways; namely, the modification of existing hydrologic models and/or the use of models that were specifically designed to use snowcovered area. A daily snowmelt runoff model was used with LANDSAT data to simulate discharge on remote basins in the Wind River Mountains of Wyoming. Daily predicted and actual flows compare closely, and, summarized over the entire snowmelt season (April 1 - September 30), the average difference is only three percent. The model and snowcovered area data are currently being tested on additional watersheds to determine the method's transferability.

  16. Variation trend of snowmelt runoff in the Japanese Alps catchment

    NASA Astrophysics Data System (ADS)

    Suzuki, K.

    2015-12-01

    The Japanese Alps region is known to experience some of the heaviest snowfall in the world. In this region, precipitation brought by snowfall is more important as a water resource than rainfall. This region experiences exceptionally heavy snowfall that is extreme even by world standard, and in spring, the melting snow becomes a valuable water resource for the region. Snow plays the role of a natural white dam by accumulating in watersheds during winter. Recent studies have reported that the amount of snowfall in Japan will decrease as a result of global warming. However, these studies used data observed at low altitudes. The question arises whether the same theory can be applied to high-altitude mountain areas. Observations of the amount of snow have not been carried out in high-altitude mountain in Japan where the temperature is colder than the threshold temperature of snow/rain even with the temperature rise observed in recent years. Therefore, we cannot discuss the effect of global warming on the change in the amount of snow in the mountainous region of Japan based on observation data. Therefore, in this study, we discuss the relationship between snowmelt runoff and the amount of snow using observation data for the Japanese Alps catchment and present the results of some meteorological observations we carried out at high-altitude sites in the Japanese Alps region.

  17. Application of Snowmelt Runoff Model (SRM) in ungagged Manasi River Basin, Northwest China

    NASA Astrophysics Data System (ADS)

    Chen, X.; Liang, S.; Bao, A.

    2014-12-01

    The climate change will have great impacts on snowmelt runoff, including prolong of snowmelt period, advance of peak in snowmelt discharges, and the notable increase of snowmelt volume in melt-season. These changes have great significance and caused widespread concerns in arid region because the snowmelt runoff is one of the most important water resources which seriously related to the agricultural and socio-economic development. However, limited by the poor geographical environment and spare distribution of in situ observations, the snowmelt runoff simulation are still a challenge in some ungagged catchment. The Snowmelt Runoff Model (SRM) is one of the few models in the world that requires remote sensing derived snow cover as model input. Based on the SRM hydrological model, this study simulated the snowmelt process in melt-season of 2007 in Manasi River Basin and try to make contribution to the understanding of snowmelt runoff process in such ungagged catchment. The conclusions are as follows: the SRM model represented a certain semi-distributed model with physical mechanism, has a good applicability in scarcely meteorological and hydrological suits distributed catchments. The correlation coefficient between computed runoff and measured runoff could reach 0.93 with 2.57% volume derivation in ideal situation without the effects of instantaneous precipitation during March-Jun, 2007. As one of the most important input variables, the daily snow cover extent derived from MOD10A1 are effectively make up the lack of in suit snow observations. The classification accuracy of MOD10A1 reached 0.81 in 95% confidence level on 3×3 pixels statistical scale verified by the Landsat 5 TM images. Meanwhile, temperature and precipitation played important roles on snowmelt runoff simulation, the correlation coefficient between daily temperature and daily measured runoff is 0.46 in 95% confidence level. The lase rate of discharge determined the basic shape of computed runoff, while

  18. A proposed streamflow data program for Michigan

    USGS Publications Warehouse

    Bent, P.C.

    1970-01-01

    An evaluation of the streamflow data available in Michigan was made to provide guidelines for planning future water resource programs. The basic steps in the evaluation procedure were (1) definition of the long-term goals of the streamflow data program in quantitative form, (2) examination and analysis of all available data to determine which goals have already been met, and (3) consideration of alternate programs and techniques to meet the remaining objectives. It was found that most goals could not be met by regionalization of the data for gaged basins by regression analysis. This fact indicates that few changes can be made in the present program on the basis of computing data by regression formulas. However, regression formulas that include factors not evaluated as a part of this study, may provide a basis for regional streamflow analysis. The evaluation indicated that some changes in the streamgaging network can be made on the basis of length of records already collected. A streamflow data program based on the guidelines developed in this rstudy is proposed for the future.

  19. The Probability Distribution of Daily Streamflow

    NASA Astrophysics Data System (ADS)

    Blum, A.; Vogel, R. M.

    2015-12-01

    Flow duration curves (FDCs) are a graphical illustration of the cumulative distribution of streamflow. Daily streamflows often range over many orders of magnitude, making it extremely challenging to find a probability distribution function (pdf) which can mimic the steady state or period of record FDC (POR-FDC). Median annual FDCs (MA-FDCs) describe the pdf of daily streamflow in a typical year. For POR- and MA-FDCs, Lmoment diagrams, visual assessments of FDCs and Quantile-Quantile probability plot correlation coefficients are used to evaluate goodness of fit (GOF) of candidate probability distributions. FDCs reveal that both four-parameter kappa (KAP) and three-parameter generalized Pareto (GP3) models result in very high GOF for the MA-FDC and a relatively lower GOF for POR-FDCs at over 500 rivers across the coterminous U.S. Physical basin characteristics, such as baseflow index as well as hydroclimatic indices such as the aridity index and the runoff ratio are found to be correlated with one of the shape parameters (kappa) of the KAP and GP3 pdfs. Our work also reveals several important areas for future research including improved parameter estimators for the KAP pdf, as well as increasing our understanding of the conditions which give rise to improved GOF of analytical pdfs to large samples of daily streamflows.

  20. Streamflow life cycles spanning the USA

    NASA Astrophysics Data System (ADS)

    Jasechko, S.; McDonnell, J.; Welker, J. M.

    2014-12-01

    Rivers are replenished by precipitation that works its way through watersheds and into stream networks. The time that precipitation requires to travel into a stream regulates contaminant transports, nutrient mobility and bedrock weathering, but has not yet been evaluated at a continental scale. Here we synthesize a pan-U.S.A. dataset of rain, snow and streamflow 18O/16O and 2H/1H ratios and analyze the data to show that the lion's share of USA streamflow is generated by precipitation that takes ~2 months to ~2.5 years to flush through watersheds and into networks of streams (i.e., rivers replenished by "infant-to-toddler aged" precipitation). These streamflow ages are considerably shorter than the average amount of time that water spends within streams themselves (~1 month, globally), and much shorter than the global groundwater residence time of more than ~1000 years. We also estimate the depth of "dynamic" groundwater storage that actively generates the majority of streamflow and discover that less than ~1% of watershed flowpaths generate the bulk of continental runoff. Our finding showcases that the most hydrologically-active zone within Earth's hydrosphere is located nearest to the surface where atmosphere-biosphere-lithosphere interactions are at a maximum. This research emphasizes the importance of critical zone research for developing accurate forecasts of how human modifications to the land and climate will impact downstream water, nutrient and contaminant fluxes.

  1. HYDRORECESSION: A toolbox for streamflow recession analysis

    NASA Astrophysics Data System (ADS)

    Arciniega, S.

    2015-12-01

    Streamflow recession curves are hydrological signatures allowing to study the relationship between groundwater storage and baseflow and/or low flows at the catchment scale. Recent studies have showed that streamflow recession analysis can be quite sensitive to the combination of different models, extraction techniques and parameter estimation methods. In order to better characterize streamflow recession curves, new methodologies combining multiple approaches have been recommended. The HYDRORECESSION toolbox, presented here, is a Matlab graphical user interface developed to analyse streamflow recession time series with the support of different tools allowing to parameterize linear and nonlinear storage-outflow relationships through four of the most useful recession models (Maillet, Boussinesq, Coutagne and Wittenberg). The toolbox includes four parameter-fitting techniques (linear regression, lower envelope, data binning and mean squared error) and three different methods to extract hydrograph recessions segments (Vogel, Brutsaert and Aksoy). In addition, the toolbox has a module that separates the baseflow component from the observed hydrograph using the inverse reservoir algorithm. Potential applications provided by HYDRORECESSION include model parameter analysis, hydrological regionalization and classification, baseflow index estimates, catchment-scale recharge and low-flows modelling, among others. HYDRORECESSION is freely available for non-commercial and academic purposes.

  2. Long-range forecasting of intermittent streamflow

    NASA Astrophysics Data System (ADS)

    van Ogtrop, F. F.; Vervoort, R. W.; Heller, G. Z.; Stasinopoulos, D. M.; Rigby, R. A.

    2011-01-01

    Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a probabilistic statistical model to forecast streamflow 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS) to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth) of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill.

  3. Long-range forecasting of intermittent streamflow

    NASA Astrophysics Data System (ADS)

    van Ogtrop, F. F.; Vervoort, R. W.; Heller, G. Z.; Stasinopoulos, D. M.; Rigby, R. A.

    2011-11-01

    Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a statistical model to forecast streamflow up to 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS) to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth) of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 6 and 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill.

  4. Remote Sensing-based Methodologies for Snow Model Adjustments in Operational Streamflow Prediction

    NASA Astrophysics Data System (ADS)

    Bender, S.; Miller, W. P.; Bernard, B.; Stokes, M.; Oaida, C. M.; Painter, T. H.

    2015-12-01

    Water management agencies rely on hydrologic forecasts issued by operational agencies such as NOAA's Colorado Basin River Forecast Center (CBRFC). The CBRFC has partnered with the Jet Propulsion Laboratory (JPL) under funding from NASA to incorporate research-oriented, remotely-sensed snow data into CBRFC operations and to improve the accuracy of CBRFC forecasts. The partnership has yielded valuable analysis of snow surface albedo as represented in JPL's MODIS Dust Radiative Forcing in Snow (MODDRFS) data, across the CBRFC's area of responsibility. When dust layers within a snowpack emerge, reducing the snow surface albedo, the snowmelt rate may accelerate. The CBRFC operational snow model (SNOW17) is a temperature-index model that lacks explicit representation of snowpack surface albedo. CBRFC forecasters monitor MODDRFS data for emerging dust layers and may manually adjust SNOW17 melt rates. A technique was needed for efficient and objective incorporation of the MODDRFS data into SNOW17. Initial development focused in Colorado, where dust-on-snow events frequently occur. CBRFC forecasters used retrospective JPL-CBRFC analysis and developed a quantitative relationship between MODDRFS data and mean areal temperature (MAT) data. The relationship was used to generate adjusted, MODDRFS-informed input for SNOW17. Impacts of the MODDRFS-SNOW17 MAT adjustment method on snowmelt-driven streamflow prediction varied spatially and with characteristics of the dust deposition events. The largest improvements occurred in southwestern Colorado, in years with intense dust deposition events. Application of the method in other regions of Colorado and in "low dust" years resulted in minimal impact. The MODDRFS-SNOW17 MAT technique will be implemented in CBRFC operations in late 2015, prior to spring 2016 runoff. Collaborative investigation of remote sensing-based adjustment methods for the CBRFC operational hydrologic forecasting environment will continue over the next several years.

  5. Snowmelt timing alters shallow but not deep soil moisture in the Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Blankinship, Joseph C.; Meadows, Matthew W.; Lucas, Ryan G.; Hart, Stephen C.

    2014-02-01

    Roughly one-third of the Earth's land surface is seasonally covered by snow. In many of these ecosystems, the spring snowpack is melting earlier due to climatic warming and atmospheric dust deposition, which could greatly modify soil water resources during the growing season. Though snowmelt timing is known to influence soil water availability during summer, there is little known about the depth of the effects and how long the effects persist. We therefore manipulated the timing of seasonal snowmelt in a high-elevation mixed-conifer forest in a Mediterranean climate during consecutive wet and dry years. The snow-all-gone (SAG) date was advanced by 6 days in the wet year and 3 days in the dry year using black sand to reduce the snow surface albedo. To maximize variation in snowmelt timing, we also postponed the SAG date by 8 days in the wet year and 16 days in the dry year using white fabric to shade the snowpack from solar radiation. We found that deeper soil water (30-60 cm) did not show a statistically significant response to snowmelt timing. Shallow soil water (0-30 cm), however, responded strongly to snowmelt timing. The drying effect of accelerated snowmelt lasted 2 months in the 0-15 cm depth and at least 4 months in the 15-30 cm depth. Therefore, the legacy of snowmelt timing on soil moisture can persist through dry periods, and continued earlier snowmelt due to climatic warming and windblown dust could reduce near-surface water storage and availability to plants and soil biota.

  6. Application of a Distributed, Physically Based, Hydrologic Model to Improve Streamflow Forecasts in the Headwaters of the Rio Grande

    NASA Astrophysics Data System (ADS)

    Boyle, D. P.; Viger, R.; Markstrom, S.; Hay, L. E.; McConnell, J. R.; Leavesley, G.; Bardsley, T.

    2001-05-01

    A significant portion of the runoff in the Rio Grande begins as seasonal snowpack in the headwaters above the USGS stream gaging station at Del Norte, CO. Resource managers in the Rio Grande rely on accurate forecasts of water availability and flow at the Del Norte gage to make important decisions aimed at achieving a balance among the many different and competing water uses such as municipal, fish and wildlife, agricultural, and water quality. In this study, a distributed, physically based hydrologic model is used to investigate the degree of spatial and temporal distribution of snow and the processes that control snowmelt necessary to accurately simulate streamflow at the Del Norte gage. Specifically, snow distribution and surface runoff are estimated using a combination of the USGS Modular Modeling System (MMS), GIS Weasel, Precipitation-Runoff Modeling System (PRMS), and XYZ snow distribution model. The work represents a highly collaborative effort between researchers at the Desert Research Institute and the USGS as part of initial Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA) goals to improve models of snow distribution and snowmelt processes.

  7. Application of a Distributed, Physically Based, Hydrologic Model to Improve Streamflow Forecasts in the Upper Rio Grande Basin

    NASA Astrophysics Data System (ADS)

    Gorham, T. A.; Boyle, D. P.; McConnell, J. R.; Lamorey, G. W.; Markstrom, S.; Viger, R.; Leavesley, G.

    2001-12-01

    Approximately two-thirds of the runoff in the Rio Grande begins as seasonal snowpack in the headwaters above the USGS stream gaging stations at several points (nodes) above Albuquerque, New Mexico. Resource managers in the Rio Grande Basin rely on accurate short and long term forecasts of water availability and flow at these nodes to make important decisions aimed at achieving a balance among many different and competing water uses such as municipal, fish and wildlife, agricultural, and water quality. In this study, a distributed, physically based hydrologic model is used to investigate the degree of spatial and temporal distribution of snow and the processes that control snowmelt necessary to accurately simulate streamflow at seven of these nodes. Specifically, snow distribution and surface runoff are estimated using a combination of the USGS Modular Modeling System (MMS), GIS Weasel, Precipitation-Runoff Modeling System (PRMS), and XYZ snow distribution model. This highly collaborative work between researchers at the Desert Research Institute and the USGS is an important part of SAHRA (Sustainability of semi-Arid Hydrology and Riparian Areas) efforts aimed at improving models of snow distribution and snowmelt processes.

  8. Monthly streamflow forecasting using Gaussian Process Regression

    NASA Astrophysics Data System (ADS)

    Sun, Alexander Y.; Wang, Dingbao; Xu, Xianli

    2014-04-01

    Streamflow forecasting plays a critical role in nearly all aspects of water resources planning and management. In this work, Gaussian Process Regression (GPR), an effective kernel-based machine learning algorithm, is applied to probabilistic streamflow forecasting. GPR is built on Gaussian process, which is a stochastic process that generalizes multivariate Gaussian distribution to infinite-dimensional space such that distributions over function values can be defined. The GPR algorithm provides a tractable and flexible hierarchical Bayesian framework for inferring the posterior distribution of streamflows. The prediction skill of the algorithm is tested for one-month-ahead prediction using the MOPEX database, which includes long-term hydrometeorological time series collected from 438 basins across the U.S. from 1948 to 2003. Comparisons with linear regression and artificial neural network models indicate that GPR outperforms both regression methods in most cases. The GPR prediction of MOPEX basins is further examined using the Budyko framework, which helps to reveal the close relationships among water-energy partitions, hydrologic similarity, and predictability. Flow regime modification and the resulting loss of predictability have been a major concern in recent years because of climate change and anthropogenic activities. The persistence of streamflow predictability is thus examined by extending the original MOPEX data records to 2012. Results indicate relatively strong persistence of streamflow predictability in the extended period, although the low-predictability basins tend to show more variations. Because many low-predictability basins are located in regions experiencing fast growth of human activities, the significance of sustainable development and water resources management can be even greater for those regions.

  9. A multisite seasonal ensemble streamflow forecasting technique

    NASA Astrophysics Data System (ADS)

    Bracken, Cameron; Rajagopalan, Balaji; Prairie, James

    2010-03-01

    We present a technique for providing seasonal ensemble streamflow forecasts at several locations simultaneously on a river network. The framework is an integration of two recent approaches: the nonparametric multimodel ensemble forecast technique and the nonparametric space-time disaggregation technique. The four main components of the proposed framework are as follows: (1) an index gauge streamflow is constructed as the sum of flows at all the desired spatial locations; (2) potential predictors of the spring season (April-July) streamflow at this index gauge are identified from the large-scale ocean-atmosphere-land system, including snow water equivalent; (3) the multimodel ensemble forecast approach is used to generate the ensemble flow forecast at the index gauge; and (4) the ensembles are disaggregated using a nonparametric space-time disaggregation technique resulting in forecast ensembles at the desired locations and for all the months within the season. We demonstrate the utility of this technique in skillful forecast of spring seasonal streamflows at four locations in the Upper Colorado River Basin at different lead times. Where applicable, we compare the forecasts to the Colorado Basin River Forecast Center's Ensemble Streamflow Prediction (ESP) and the National Resource Conservation Service "coordinated" forecast, which is a combination of the ESP, Statistical Water Supply, a principal component regression technique, and modeler knowledge. We find that overall, the proposed method is equally skillful to existing operational models while tending to better predict wet years. The forecasts from this approach can be a valuable input for efficient planning and management of water resources in the basin.

  10. Influence of snowmelt events on hillslope soil loss in Mediterranean high mountainous environments.

    NASA Astrophysics Data System (ADS)

    Millares, Agustin; Torres, Raquel; Aguilar, Cristina; José Polo, María

    2014-05-01

    This study analyzes the influence of snowmelt events on hillslope erosion processes in a high-mountainous Mediterranean basin. Here, semi-arid conditions and high uncertainty of meteorological agents lead to huge yields of both, suspended sediments and bedload contributions. The proposed methodology includes field campaigns of suspended sediments at hillslope scale and the temporal analysis of the snow cover evolution with available images from MODIS sensor. In addition, a physically-based hydrological model was applied to both, the estimation of snowmelt runoff contributions and to validate snow cover derived from remote sensing data. The obtained results showed certain patterns and relationships between snowmelt flows and suspended sediment contributions at different temporal scales (e.g. daily, weekly, etc.). These relationships are consistent with those reported in other works in Mediterranean high mountainous areas, and point to the significant influence of intense snowmelt pulses. The heterogeneity of the different erosive processes within the study area adds complexity to the estimation of these contributions at basin scale. The relatively low measured concentration values (90 mg/L) suggest that the snowmelt contribution to the sediment load could be negligible when compared with other erosion processes (>1200 mg/L from gullying, rill and interill). However, the length of the snowmelt period (1-2 months) and the recurrent annual sequence of these contributions make it advisable not to ignore this process and its influence on dam siltation.

  11. Evaluating a hierarchy of snowmelt models at a watershed in the Canadian Prairies

    NASA Astrophysics Data System (ADS)

    Singh, Purushottam Raj; Gan, Thian Yew; Gobena, Adam Kenea

    2009-02-01

    Three semidistributed snowmelt models (SDSM) were developed and applied to the Paddle River Basin (PRB) in the Canadian Prairies: (1) A physics-based, energy balance model (SDSM-EBM) that considers vertical energy exchange processes in open and forested areas, and snowmelt processes that include liquid and ice phases separately; (2) a modified temperature index model (SDSM-MTI) that uses both near surface soil temperature (Tg) and air temperature (Ta); and (3) a standard temperature index (SDSM-TI) method using Ta only. Other than the "regulatory" effects of beaver dams that affected the validation results on simulated runoff, both SDSM-MTI and SDSM-EBM simulated reasonably accurate snowmelt runoff, snow water equivalent, and snow depth. For the PRB, where snowpack is shallow to moderately deep and winter is relatively severe, the advantage of using both Ta and Tg is partly attributed to Tg showing a stronger correlation with solar radiation than Ta during the spring snowmelt season and partly attributed to the onset of major snowmelt which usually happens when Tg approaches 0°C. After resetting model parameters so that SDSM-MTI degenerated to SDSM-TI (the effect of Tg is completely removed), the model performance worsened, even after recalibrating the melt factors using Ta alone. It seems that if reliable Tg data are available, they should be utilized to model the snowmelt processes in a prairie environment, particularly if the temperature-index approach is adopted.

  12. Synchronous flowering despite differences in snowmelt timing among habitats of Empetrum hermaphroditum

    NASA Astrophysics Data System (ADS)

    Bienau, Miriam J.; Kröncke, Michael; Eiserhardt, Wolf L.; Otte, Annette; Graae, Bente J.; Hagen, Dagmar; Milbau, Ann; Durka, Walter; Eckstein, R. Lutz

    2015-11-01

    The topography within arctic-alpine landscapes is very heterogeneous, resulting in diverse snow distribution patterns, with different snowmelt timing in spring. This may influence the phenological development of arctic and alpine plant species and asynchronous flowering may promote adaptation of plants to their local environments. We studied how flowering phenology of the dominant dwarf shrub Empetrum hermaphroditum varied among three habitats (exposed ridges, sheltered depressions and birch forest) differing in winter snow depth and thus snowmelt timing in spring, and whether the observed patterns were consistent across three different study areas. Despite significant differences in snowmelt timing between habitats, full flowering of E. hermaphroditum was nearly synchronous between the habitats, and implies a high flowering overlap. Our data show that exposed ridges, which had a long lag phase between snowmelt and flowering, experienced different temperature and light conditions than the two late melting habitats between snowmelt and flowering. Our study demonstrates that small scale variation seems matter less to flowering of Empetrum than interannual differences in snowmelt timing.

  13. Infrastructure Improvements for Snowmelt Runoff Forecasting and Assessments of Climate Change Impacts on Water Supplies in the Rio Grande Basin

    NASA Astrophysics Data System (ADS)

    Rango, A.; Steele, C. M.; Demouche, L.

    2009-12-01

    , namely, the Rio Grande near Del Norte, CO and the Rio Hondo, Rio Chama, and Castillo Creek in NM, all tributaries of the Rio Grande basin. An additional 21 sub basins will be added as the development and testing of methods progresses. High spatial resolution Landsat TM data (30 m) are being used to evaluate estimates of snow cover maps from moderate spatial resolution data from Terra MODIS (250m and 500 m). Currently MODIS provides optimal temporal sampling (daily data) but the most effective MODIS-based snow cover mapping method has yet to be determined. We aim to identify the best MODIS snow-mapping algorithm for the Rio Grande area. For the snowmelt modeling, we are using an updated revision of SRM which directly accepts remote sensing snow cover inputs but can also automatically assess the climate change effects of future scenarios. The methods under development are intended for operational use by interested water resources agencies. With this end in mind, we will be developing an ArcGIS Toolbox (ESRI) and manual that will incorporate all the tools and instructions necessary for data download, re-projection and formatting, modeling and streamflow estimation.

  14. Geochemical baseline studies and relations between water quality and streamflow in the upper Blackfoot Watershed, Montana: data for July 1997-December 1998

    USGS Publications Warehouse

    Nagorski, Sonia A.; Moore, Johnnie N.; Smith, David B.

    2001-01-01

    We used ultraclean sampling techniques to study the solute (operationally defined as <0.2 ?m) surface water geochemistry at five sites along the Upper Blackfoot River and four sites along the Landers Fork, some in more detail and more regularly than others. We collected samples also from Hogum Creek, a tributary to the Blackfoot, from Copper Creek, a tributary to the Landers Fork, and from ground water seeps contributing to the flow along the Landers Fork. To better define the physical dynamics of the hydrologic system and to determine geochemical loads, we measured streamflow at all the sites where we took samples for water quality analysis. The Upper Blackfoot River, which drains historic mines ca. 20 Km upstream of the study area, had higher trace metal concentrations than did the Landers Fork, which drains the pristine Scapegoat Wilderness area. In both rivers, many of the major elements were inversely related to streamflow, and at some sites, several show a hysteresis effect in which the concentrations were lower on the rising limb of the hydrograph than on the falling limb. However, many of the trace elements followed far more irregular trends, especially in the Blackfoot River. Elements such as As, Cu, Fe, Mn, S, and Zn exhibited complex and variable temporal patterns, which included almost no response to streamflow differences, increased concentrations following a summer storm and at the start of snowmelt in the spring, and/or increased concentrations throughout the course of spring runoff. In summary, complex interactions between the timing and magnitude of streamflow with physical and chemical processes within the watershed appeared to greatly influence the geochemistry at the sites, and streamflow values alone were not good predictors of solute concentrations in the rivers.

  15. Estimation of Median Streamflows at Perennial Stream Sites in Hawaii

    USGS Publications Warehouse

    Fontaine, Richard A.; Wong, Michael F.; Matsuoka, Iwao

    1992-01-01

    The most accurate estimates of median streamflows at perennial stream sites in Hawaii are those made at streamflow-gaging stations. Two alternative methods for estimating median streamflows at ungaged sites are described in this report. Multiple-regression equations were developed for estimating median streamflows at ungaged, unregulated, perennial stream sites. The equations relate combinations of drainage area, mean altitude of the main stream channel, and mean annual precipitation to median streamflow. Streamflow data from 56 long-term continuous-record gaging stations were used in the analysis. Median-streamflow data for all 56 sites were adjusted using record-extension techniques to reflect base period (1912 through 1986) conditions. Hawaii was subdivided into two geographic groups and multiple-regression equations were developed for each. The standard error of predication for the equation developed for the first group, the islands of Oahu, Molokai, and Hawaii, is 41 percent. The standard error of predication for the equation developed for the second group, the islands of Kauai and Maui, is 54 percent. A method for estimating median-streamflow, based on discharge measurements and data from nearby streamflow-gaging stations, was also developed for 27 regulated, perennial windward Oahu sites. Standard errors of prediction for 23 of the sites range from 5 to 34 percent. Median-streamflow estimates for the four remaining sites were considered poor and no measures of accuracy are provided. Discharge measurements can be used to make estimates of median streamflows at ungaged, regulated sites where the regression equations developed in this report are not applicable. Discharge measurements can also be used to make estimates of median streamflows at ungaged, unregulated sites. Estimates of median streamflows based on discharge measurements have greater standard errors than estimates based on continuous streamflow records and in general have smaller standard errors

  16. The impact of black carbon deposition on snowpack and streamflow in the Wasatch mountains in Utah: A study using MODIS albedo data, statistical modeling and machine learning

    NASA Astrophysics Data System (ADS)

    Panthail, Jai Kanth

    Salt Lake City, located at the base of the Wasatch mountain range in Utah, receives a majority of its potable water from a system of mountain creeks. Snowmelt runoff from mountain watersheds provides the city a clean and relatively inexpensive water supply, and has been a key driver in the city's growth and prosperity. There has been keen interest recently on the possible impact of the deposition of darkening matter, such as dust and black carbon (BC) on the snow, which might lead to a decrease in its 'albedo' or reflective capacity. Such a decrease is expected to result in faster melting of the snow, shifting springtime streamflows to winter. This study aimed to develop a modeling framework to estimate the impact on snowmelt-driven runoff due to various BC deposition scenarios. An albedo simulation model, Snow, Ice, and Aerosol Radiation (SNICAR) model, was used to understand the evolution of albedo under different BC loadings. An Albedo-Snow Water Equivalent (A-SWE) model was developed using a machine learning technique, 'Random Forests', to quantify the effect on the state of snowpack under various albedo-change scenarios. An Albedo-Snow Water Equivalent-Streamflow (A-SWE-S) model was designed using an advanced statistical modeling technique, 'Generalized Additive Models (GAMs)', to extend the analysis to streamflow variations. All models were tested and validated using robust k-fold cross-validation. Albedo data were obtained from NASA's MODIS satellite platform. The key results found the snowpack to be depleted 2-3 weeks later with an albedo increase between 5-10% above current conditions, and 1-2 weeks earlier under albedo decrease of 5-10% below current conditions. Future work will involve improving the A-SWE-S model by better accounting for lagged effects, and the use of results from both models in a city-wide systems model to understand water supply reliability under combined deposition and climate change scenarios.

  17. Distributed Assimilation of Satellite-based Snow Extent for Improving Simulated Streamflow in Mountainous, Dense Forests: An Example Over the DMIP2 Western Basins

    NASA Technical Reports Server (NTRS)

    Yatheendradas, Soni; Peters-Lidard, Christa D.; Koren, Victor; Cosgrove, Brian A.; DeGoncalves, Luis G. D.; Smith, Michael; Geiger, James; Cui, Zhengtao; Borak, Jordan; Kumar, Sujay V.; Riggs, George; Mizukami, Naoki

    2012-01-01

    Snow cover area affects snowmelt, soil moisture, evapotranspiration, and ultimately streamflow. For the Distributed Model Intercomparison Project - Phase 2 Western basins, we assimilate satellite-based fractional snow cover area (fSCA) from the Moderate Resolution Imaging Spectroradiometer, or MODIS, into the National Weather Service (NWS) SNOW-17 model. This model is coupled with the NWS Sacramento Heat Transfer (SAC-HT) model inside the National Aeronautics and Space Administration's (NASA) Land Information System. SNOW-17 computes fSCA from snow water equivalent (SWE) values using an areal depletion curve. Using a direct insertion, we assimilate fSCAs in two fully distributed ways: 1) we update the curve by attempting SWE preservation, and 2) we reconstruct SWEs using the curve. The preceding are refinements of an existing simple, conceptually-guided NWS algorithm. Satellite fSCA over dense forests inadequately accounts for below-canopy snow, degrading simulated streamflow upon assimilation during snowmelt. Accordingly, we implement a below-canopy allowance during assimilation. This simplistic allowance and direct insertion are found to be inadequate for improving calibrated results, still degrading them as mentioned above. However, for streamflow volume for the uncalibrated runs, we obtain: (1) substantial to major improvements (64-81 %) as a percentage of the control run residuals (or distance from observations), and (2) minor improvements (16-22 %) as a percentage of observed values. We highlight the need for detailed representations of canopy-snow optical radiative transfer processes in mountainous, dense forest regions if assimilation-based improvements are to be seen in calibrated runs over these areas.

  18. Seasonal change in precipitation, snowpack, snowmelt, soil water and streamwater chemistry, northern Michigan

    USGS Publications Warehouse

    Stottlemyer, R.; Toczydlowski, D.

    1999-01-01

    We have studied weekly precipitation, snowpack, snowmelt, soil water and streamwater chemistry throughout winter for over a decade in a small (176 ha) northern Michigan watershed with high snowfall and vegetated by 60 to 80 year-old northern hardwoods. In this paper, we examine physical, chemical, and biological processes responsible for observed seasonal change in streamwater chemistry based upon intensive study during winter 1996-1997. The objective was to define the contributions made to winter and spring streamwater chemical concentration and flux by processes as snowmelt, over-winter forest floor and surface soil mineralization, immobilization, and exchange, and subsurface flowpath. The forest floor and soil were unfrozen beneath the snowpack which permitted most snowmelt to enter. Over-winter soil mineralization and other biological processes maintain shallow subsurface ion and dissolved organic carbon (DOC) reservoirs. Small, but steady, snowmelt throughout winter removed readily mobilized soil NO3- which resulted in high over-winter streamwater concentrations but little flux. Winter soil water levels and flowpaths were generally deep which increased soil water and streamwater base cation (C(B)), HCO3-, and Si concentrations. Spring snowmelt increased soil water levels and removal of ions and DOC from the biologically active forest floor and shallow soils. The snowpack solute content was a minor component in determining streamwater ion concentration or flux during and following peak snowmelt. Exchangeable ions, weakly adsorbed anions, and DOC in the forest floor and surface soils dominated the chemical concentration and flux in soil water and streamwater. Following peak snowmelt, soil microbial immobilization and rapidly increased plant uptake of limiting nutrients removed nearly all available nitrogen from soil water and streamwater. During the growing season high evapotranspiration increased subsurface flowpath depth which in turn removed weathering

  19. Global to local scale simulations of streamflow in the Merced, American, and Carson Rivers, Sierra Nevada, California

    USGS Publications Warehouse

    Dettinger, M.D.; Cayan, D.R.; Mo, K.; Jeton, A.E.

    1999-01-01

    Atmospheric moisture transport and moisture budgets during winter (December-April) simulated by the National Centers for Environmental Prediction (NCEP) regional spectral model (RSM) are examined and used to simulate streamflow variations in the Sierra Nevada. The RSM was nested in 2"-latitude x 2"-longitude NCEPreanalyzed atmospheric-data fields (as a surrogate for a perfect forecast system operating at the global scale). Precipitation, temperature, and solar insolation simulated by the RSM on a 50-km grid were inputted directly to precipitation-runoff models of the Merced, American, and Carson Rivers in an evaluation of the potential for end-to-end forecasting of streamflow and snowmelt runoff from the Sierra Nevada, near 39"N 120"W. Over the western United States, the RSM captures both patterns and magnitudes of precipitation (e.g., Fig. I illustrates observed and simulated precipitation for winter 1982-83). The RSM has dry biases in the Southeast and over the Gulf of Mexico, but it captures interannual and intraseasonal variations well. During most El Nifios, it simulates a precipitation dipole over the western states with wetter-than-normal conditions in California and drier-than-normal in the Pacific Northwest. The Northeast is relatively dry and the southern states are wet, as in observations. The RSM did equally well during La Niiia winters.

  20. Experimental investigation of road snow-melting based on CNFP self-heating concrete

    NASA Astrophysics Data System (ADS)

    Zhang, Qiangqiang; Li, Hui

    2011-04-01

    In this study, the road snow-melting system consisted of CNFP thermal source, AlN/Epoxy-based insulated-encapsulated layer and MWCNT/cement-based thermal conductive layer, was fabricated. The carbon nano-fiber paper (CNFP) taken excellent thermal and electrical properties was integrated into snow-melting system as the high-efficient thermal source. The remarkable electro-thermal and resistive properties of CNFP with the thickness of 0.38mm were investigated, and verified much higher efficiency electro-thermal property than other papery materials. The linearly temperature-dependent effect of CNFP resistivity was founded in certain temperature scope and met the line model as a function of temperature. Carbon nanotubes (CNT) attracted many filed scholars' focus based on its unique thermal conduction as a strong thermal-transferring candidate since it was founded. A new approach, named electric repulsion/high-frequency oscillatory dispersion, was proposed to fabricate the MWCNT/cement-based composites. The sample, filled with 3% MWCNT by the amount of cement, presents the significant improvement of thermal conductive property in contrast with other fillers and dispersing methods, which was integrated into snow-melting system with other parts as the thermal conductive layer material. The AlN/Epoxy-based composite, filled with 20% micron-AlN by the weight of mixture as the best candidate of insulated-capsulation material, would be used to guarantee the insulation. Due to the snow-melting field test, the snow-melting characteristics of integrated snow-melting system, dependent on the ambient temperature, wind speed, heat flux density and snow thickness, were investigated. The results not only verified the high-efficient, stable, feasible and economic properties, but also provided the valuable parameters for further snow-melting or ice-deicing investigation.

  1. 5 years of continuous seismic monitoring of snowmelt cycles in a Pyrenean valley

    NASA Astrophysics Data System (ADS)

    Diaz, Jordi; Sánchez-Pastor, Pilar; Gallart, Josep

    2016-04-01

    In recent years the analysis of background seismic noise variations in the proximity of river channels has revealed as a useful tool to monitor river flow, even for modest discharges. We will focus here in the application of this methodology to study the snowmelt cycle in an Pyrenean valley during the last 5 years, using data from the seismic geophysical station located inside the Canfranc Underground Laboratory (Central Pyrenees). Diaz et al. (2014) first identified in the seismic data the signature of river flow increases associated to snowmelt episodes in the catchment area of the Aragon River, based on the marked correlation between the seismic energy variations in the 2-8 Hz frequency band and the estimated variations in water resources from snowfall. The analysis of seismic data during the snowmelt periods allows to identify a clear 24h cycle, with energy increasing from about 14:00 GMT, remaining at a relatively high level for 12 hours and then smoothly vanishing. The spectrogram reveals richer information, as clear variations in the frequency content can be detected during the time intervals in which the amplitude of the seismic signal remains constant. The data available so far allow to compare the evolution of snowmelt in five seasons with very different hydrological behavior. The 2011 and 2012 seasons have been dry, with snow volumes 30-50 % beneath the average values, while the 2013, 2014 and in particular the 2015 seasons have been largely above the mean. Those variations are reflected in the seismic data, which allow to monitor the time occurrence of the main snowmelt stages for each season and to estimate the intensity of the different snowmelt episodes. Therefore, seismic data can be useful for long term monitoring of snowmelt in Alpine-style mountains.

  2. Streamflow trends in the United States

    NASA Astrophysics Data System (ADS)

    Lins, Harry F.; Slack, James R.

    Secular trends in streamflow are evaluated for 395 climate-sensitive streamgaging stations in the conterminous United States using the non-parametric Mann-Kendall test. Trends are calculated for selected quantiles of discharge, from the 0th to the 100th percentile, to evaluate differences between low-, medium-, and high-flow regimes during the twentieth century. Two general patterns emerge; trends are most prevalent in the annual minimum (Q0) to median (Q50) flow categories and least prevalent in the annual maximum (Q100) category; and, at all but the highest quantiles, streamflow has increased across broad sections of the United States. Decreases appear only in parts of the Pacific Northwest and the Southeast. Systematic patterns are less apparent in the Q100 flow. Hydrologically, these results indicate that the conterminous U.S. is getting wetter, but less extreme.

  3. Acoustic systems for the measurement of streamflow

    USGS Publications Warehouse

    Laenen, Antonius; Smith, Winchell

    1982-01-01

    Very little information is available concerning acoustic velocity meter (AVM) operation, performance, and limitations. This report provides a better understanding about the application of AVM instrumentation to streamflow measurment. Operational U.S. Geological Survey systems have proven that AVM equipment is accurate and dependable. AVM equipment has no practical upper limit of measureable velocity if sonic transducers are securely placed and adequately protected, and will measure velocitites as low as 0.1 meter per second which is normally less than the threshold level for mechanical or head-loss meters. In some situations the performance of AVM equipment may be degraded by multipath interference, signal bending, signal attenuation, and variable streamline orientation. Smaller, less-expensive, more conveniently operable microprocessor equipment is now available which should increase use of AVM systems in streamflow applications. (USGS)

  4. Short-term ensemble streamflow forecasting using operationally-produced single-valued streamflow forecasts

    NASA Astrophysics Data System (ADS)

    Regonda, Satish; Seo, Dong-Jun; Lawrence, Bill

    2010-05-01

    We present a statistical procedure that generates short-term streamflow ensemble forecasts from single-valued, or deterministic, forecasts operationally produced by the National Weather Service (NWS) River Forecast Centers (RFC). The resulting ensemble forecast provides an estimate of the uncertainty in the single-valued forecast to aid risk-based decision making by the emergency managers and by the users of the forecast products and services. The single-valued forecasts are produced at a 6-hr time step for 5 days into the future, and reflect single-valued short-term quantitative precipitation and temperature forecasts (QPF, QTF) and various run-time modifications (MOD), or manual data assimilation, by human forecasters to reduce various sources of error in the end-to-end forecast process. The proposed procedure generates 5 day-ahead ensemble traces of streamflow from a very parsimonious approximation of the conditional multivariate probability distribution of future streamflow given the single-valued streamflow forecasts, QPF and recent streamflow observations. For parameter estimation and evaluation, we used a 10-year archive of the single-valued river stage forecasts for six forecast points in Oklahoma produced operationally by the Arkansas-Red River Basin River Forecast Center (ABRFC). To evaluate the procedure, we carried out dependent and leave-one-year-out cross validation. The resulting ensemble hindcasts are then verified using the Ensemble Verification System (EVS) developed at the NWS Office of Hydrologic Development (OHD).

  5. Acoustic systems for the measurement of streamflow

    USGS Publications Warehouse

    Laenen, Antonius; Smith, Winchell

    1983-01-01

    The acoustic velocity meter (AVM), also referred to as an ultrasonic flowmeter, has been an operational tool for the measurement of streamflow since 1965. Very little information is available concerning AVM operation, performance, and limitations. The purpose of this report is to consolidate information in such a manner as to provide a better understanding about the application of this instrumentation to streamflow measurement. AVM instrumentation is highly accurate and nonmechanical. Most commercial AVM systems that measure streamflow use the time-of-travel method to determine a velocity between two points. The systems operate on the principle that point-to-point upstream travel-time of sound is longer than the downstream travel-time, and this difference can be monitored and measured accurately by electronics. AVM equipment has no practical upper limit of measurable velocity if sonic transducers are securely placed and adequately protected. AVM systems used in streamflow measurement generally operate with a resolution of ?0.01 meter per second but this is dependent on system frequency, path length, and signal attenuation. In some applications the performance of AVM equipment may be degraded by multipath interference, signal bending, signal attenuation, and variable streamline orientation. Presently used minicomputer systems, although expensive to purchase and maintain, perform well. Increased use of AVM systems probably will be realized as smaller, less expensive, and more conveniently operable microprocessor-based systems become readily available. Available AVM equipment should be capable of flow measurement in a wide variety of situations heretofore untried. New signal-detection techniques and communication linkages can provide additional flexibility to the systems so that operation is possible in more river and estuary situations.

  6. An Evaluation of Real-Time Streamflow Forecasts From a Distributed, Physically Based, Hydrologic Model Applied in the Upper Rio Grande Basin.

    NASA Astrophysics Data System (ADS)

    Gorham, T. A.; Boyle, D. P.; McConnell, J. R.; Hobson, A. N.

    2002-12-01

    Different uses compete for the water resources of the Upper Rio Grande Basin including agriculture, municipalities, industry, recreation, ecology and water quality. For water operations management in the Upper Rio Grande, resource managers rely on accurate forecasts (both short and long term) of streamflow at several locations, or nodes on the river. In this study, the USGS Precipitation Runoff Modeling System (PRMS) is used to predict quantity of runoff in the headwater basin above the USGS streamflow gage near Del Norte, Colorado. Because fine-tuning of the PRMS can result in improved forecasts, predictions were made using three adaptations of the model: 1) low-spatial resolution, 2) high-spatial resolution, 3) using an alternate method of distributing climate variables throughout the basin. A post-forecast evaluation of the real-time streamflow forecasts is made via comparisons with forecasts made by the National Resources Conservation Service (NRCS). This study is highly collaborative between researchers at the Desert Research Institute (DRI) and the USGS as part of the NSF funded Center for Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA) efforts to improve models of snow distribution and snowmelt processes.

  7. Streamflow Ensemble Generation using Climate Forecasts

    NASA Astrophysics Data System (ADS)

    Watkins, D. W.; O'Connell, S.; Wei, W.; Nykanen, D.; Mahmoud, M.

    2002-12-01

    Although significant progress has been made in understanding the correlation between large-scale atmospheric circulation patterns and regional streamflow anomalies, there is a general perception that seasonal climate forecasts are not being used to the fullest extent possible for optimal water resources management. Possible contributing factors are limited knowledge and understanding of climate processes and prediction capabilities, noise in climate signals and inaccuracies in forecasts, and hesitancy on the part of water managers to apply new information or methods that could expose them to greater liability. This work involves a decision support model based on streamflow ensembles developed for the Lower Colorado River Authority in Central Texas. Predicative skill is added to ensemble forecasts that are based on climatology by conditioning the ensembles on observable climate indicators, including streamflow (persistence), soil moisture, land surface temperatures, and large-scale recurrent patterns such as the El Ni¤o-Southern Oscillation, Pacific Decadal Oscillation, and the North Atlantic Oscillation. A Bayesian procedure for updating ensemble probabilities is outlined, and various skill scores are reviewed for evaluating forecast performance. Verification of the ensemble forecasts using a resampling procedure indicates a small but potentially significant improvement in forecast skill that could be exploited in seasonal water management decisions. The ultimate goal of this work will be explicit incorporation of climate forecasts in reservoir operating rules and estimation of the value of the forecasts.

  8. The Impact of Changing Snowmelt Timing on Non-Irrigated Crop Yield: A Parametric and Non-Parametric Approach

    NASA Astrophysics Data System (ADS)

    Murray, E. M.; Cobourn, K.; Flores, A. N.; Pierce, J. L.

    2014-12-01

    As climate changes, the final date of spring snowmelt is projected to occur earlier in the year within the western United States. This earlier snowmelt timing may impact crop yield in snow-dominated watersheds by changing the timing of water delivery to agricultural fields. There is considerable uncertainty about how agricultural impacts of snowmelt timing may vary by region, crop-type, and practices like irrigation vs. dryland farming. Establishing the relationship between snowmelt timing and agricultural yield is important for understanding how changes in large-scale climatic indices (like snowmelt date) may be associated with changes in agricultural yield. A better understanding of the influence of changes in snowmelt on non-irrigated crop yield may additionally be extrapolated to better understand how climate change may alter biomass production in non-managed ecosystems. We utilized parametric regression techniques to isolate the magnitude of impact snowmelt timing has had on historical crop yield independently of climate and spatial variables that also impact yield. To do this, we examined the historical relationship between snowmelt timing and non-irrigated wheat and barley yield using a multiple linear regression model to predict yield in several Idaho counties as a function of snowmelt date, climate variables (precipitation and growing degree-days), and spatial differences between counties. We utilized non-parametric techniques to determine where snowmelt timing has positively versus negatively impacted yield. To do this, we developed classification and regression trees to identify spatial controls (e.g. latitude, elevation) on the relationship between snowmelt timing and yield. Most trends suggest a decrease in crop yield with earlier snowmelt, but a significant opposite relationship is observed in some regions of Idaho. An earlier snowmelt date occurring at high latitudes corresponds with higher than average wheat yield. Therefore, Northern Idaho may

  9. Influence of Aspect on Snowmelt Irradiation on Forested Mountain Slopes

    NASA Astrophysics Data System (ADS)

    Ellis, C. R.; Pomeroy, J. W.

    2005-12-01

    It is well known that snowmelt energy from radiation varies due to the effects of topography and vegetation cover. However it is not well understood how the combination of topography and vegetation influences sub-canopy radiation fluxes to snow. To investigate, three natural lodgepole pine (Pinus contorta) stands in the Rocky Mountains of Marmot Creek Research Basin, Alberta, Canada were instrumented with radiometers. Radiation was observed at an open reference and beneath forests on north (20° slope; 351° azimuth) and southeast (19° slope; 126° azimuth) aspects with a level site serving as a control. Due to the presence of canopy gaps on the southeast slope, radiometers were placed in open, medium and dense parts of the stand. The pine forest exhibited variations in cover having mean tree densities of 1.83, 2.05 and 2.52 trees m-2 at southeast, level and north slopes. Both short-wave and long-wave incoming radiation fluxes were measured in sites with complete snow cover and experiencing melt. Ratios of sub-canopy short-wave irradiance to open-level site mean irradiance of 12.81 MJ m-2 d-1 were 0.38, 0.21 and 0.08 for southeast slope, level, and north slope forest sites, respectively. Sub-canopy long-wave irradiance ratios relative to the average open-level site irradiance of 9.61 MJ m-2 d-1 were 2.82, 2.82 and 2.87 respectively for southeast slope, level and north slope forest sites. Sub-canopy net radiation ratios relative to a mean net radiation of 3.2 MJ m-2 d-1 at the open-level site were 0.33, 0.09 and 0.07 for southeast, level and north slope forest sites. Lower north slope receipts of sub-canopy short-wave were found to be offset by an increased sub-canopy long-wave flux.

  10. Impacts of climate and forest changes on streamflow and water balance in a mountainous headwater stream in Southern Alberta

    NASA Astrophysics Data System (ADS)

    Mahat, V.; Anderson, A.

    2013-07-01

    Rivers in Southern Alberta are vulnerable to climate change because much of the river water originates as snow in the eastern slopes of the Rocky Mountains. Changes in likelihood of forest disturbance (wildfire, insects, logging, etc.) may also have impacts that are compounded by climate change. This study evaluates the impacts of climate and forest changes on streamflow in the upper parts of the Oldman River in Southern Alberta using a conceptual hydrological model, HBV-EC in combination with a stochastic weather generator (LARS-WG) driven by GCM (Global Climate Model) output climate data. Three climate change scenarios (A1B, A2 and B1) are selected to cover the range of possible future climate conditions (2020s, 2050s, and 2080s). GCM projected less than a 10% increase in precipitation in winter and a similar amount of precipitation decrease in summer. These changes in projected precipitation resulted in up to a 200% (9.3 mm) increase in winter streamflow in February and up to a 63% (31.2 mm) decrease in summer flow in June. This amplification is mostly driven by the projected increase in temperature that is predicted to melt winter snow earlier, possibly resulting in lower water availability in the snowmelt dominated regions during the summer. Uncertainty analysis was completed using a guided GLUE (generalized likelihood uncertainty estimation) approach to obtain the best 100 parameter sets and associated ranges of streamflows. The impacts of uncertainty were higher in spring and summer flows than in winter and fall flows. Forest change compounded the climate change impact by increasing winter flow; however, it did not reduce the summer flow.

  11. Streamflow and sediment dynamics of the Middle Rio Grande Valley, New Mexico, in the context of cottonwood recruitment

    USGS Publications Warehouse

    Milhous, Robert T.; Wondzell, Mark; Ritter, Amy

    1993-01-01

    The cottonwood gallery forests of the Middle Rio Grande floodplain in New Mexico provide important habitats for birds and other animals. Over the last century, these forests have changed significantly due to invasion of exotics such as salt cedar and Russian olive, which compete with native cottonwoods, and changes in water use both in the valley and upstream. To successfully germinate and establish, cottonwoods require an adequate water supply, abundant sunlight, and bare, litter-free substrate. Native cottonwoods are adapted to a natural snowmelt hydrograph characterized by spring floods in late May or early June and gradually receding streamflows throughout the remainder of the summer. The natural streamflow pattern has been significantly modified by water management in the Rio Grande basin. The modified pattern is less conducive to establishment of cottonwoods than the natural pattern. In addition, exotic species now compete with native cottonwoods, and the modified flow pattern may favor these exotics. The overall objective of this study was to investigate the possibility of enhancing cottonwood establishment and recruitment along the Middle Rio Grande through streamflow manipulation and reservoir releases. The work integrates concepts of cottonwood establishment, water resources management, and river morphology, and investigates how water management might be used to preserve and enhance cottonwood gallery forests along the river. Specific objectives of the work reported herein were to: (1) develop a technique to calculate flows that will produce channel characteristics necessary to restore and sustain cottonwood gallery forests; (2) develop a model to determine a flow pattern, or sequence of flows, that will improve the potential for cottonwood establishment and recruitment; and (3) determine if the water resources can be managed to produce the desired channel characteristics and flow pattern identified in (1) and (2).

  12. Informing Water Management by Direct Use of Snow Information as Surrogate of Medium-to-Long Range Streamflow Forecast

    NASA Astrophysics Data System (ADS)

    Denaro, S.; Giuliani, M.; Castelletti, A.

    2014-12-01

    Medium-to-long range streamflow forecast provide a key assistance in anticipating hydro- climatic adverse events and prompting effective adaptation measures. For instance, accurate medium-long range streamflow forecasts have a great potential to improve water reservoir operation by enabling more efficient allocation of water volumes in time (e.g. via hedging). Unfortunately, these forecasts often lacks reliability and accuracy, especially when low-frequency climate forcing (e.g. ENSO) is not intense enough to improve the forecast lead time (e.g. in Europe), and might be computationally very demanding, In this work, we explore the direct use of both rough snow data (e.g. snow depth) and snow water equivalent estimates as surrogate of medium-to-long range streamflow forecast to inform the operation of a regulated lake. The underlying idea is that snow data contains key information on current and future water availability throughout the snow melting season that might significantly improve the operation's anticipation potential. We adopt a three step methodology: First, we compute the upper bound of the system performance by assuming perfect foresight and we assess the value of additional information as the difference between this ideal solution and current operation. Using input variable selection, we then select the most relevant snow information to explain the release trajectory associated to the upper bound operating policy. Finally, we derive the optimal policy conditioned upon the selected variables by Multi-Objecting Evolutionary Direct Policy Search. The methodology is demonstrated on the snow-dominated Lake Como river basin, in the Italian Alps. Lake Como is a regulated lake primarily used to supply water to a large cultivated area and snowmelt from May-July is the most important contribution to the creation of the seasonal storage. Results show that using raw data or simple SWE estimates can largely improve anticipation capability in the daily operation of

  13. Earlier snowmelt and warming lead to earlier but not necessarily more plant growth.

    PubMed

    Livensperger, Carolyn; Steltzer, Heidi; Darrouzet-Nardi, Anthony; Sullivan, Patrick F; Wallenstein, Matthew; Weintraub, Michael N

    2016-01-01

    Climate change over the past ∼50 years has resulted in earlier occurrence of plant life-cycle events for many species. Across temperate, boreal and polar latitudes, earlier seasonal warming is considered the key mechanism leading to earlier leaf expansion and growth. Yet, in seasonally snow-covered ecosystems, the timing of spring plant growth may also be cued by snowmelt, which may occur earlier in a warmer climate. Multiple environmental cues protect plants from growing too early, but to understand how climate change will alter the timing and magnitude of plant growth, experiments need to independently manipulate temperature and snowmelt. Here, we demonstrate that altered seasonality through experimental warming and earlier snowmelt led to earlier plant growth, but the aboveground production response varied among plant functional groups. Earlier snowmelt without warming led to early leaf emergence, but often slowed the rate of leaf expansion and had limited effects on aboveground production. Experimental warming alone had small and inconsistent effects on aboveground phenology, while the effect of the combined treatment resembled that of early snowmelt alone. Experimental warming led to greater aboveground production among the graminoids, limited changes among deciduous shrubs and decreased production in one of the dominant evergreen shrubs. As a result, we predict that early onset of the growing season may favour early growing plant species, even those that do not shift the timing of leaf expansion. PMID:27075181

  14. Earlier snowmelt and warming lead to earlier but not necessarily more plant growth

    PubMed Central

    Livensperger, Carolyn; Steltzer, Heidi; Darrouzet-Nardi, Anthony; Sullivan, Patrick F.; Wallenstein, Matthew; Weintraub, Michael N.

    2016-01-01

    Climate change over the past ∼50 years has resulted in earlier occurrence of plant life-cycle events for many species. Across temperate, boreal and polar latitudes, earlier seasonal warming is considered the key mechanism leading to earlier leaf expansion and growth. Yet, in seasonally snow-covered ecosystems, the timing of spring plant growth may also be cued by snowmelt, which may occur earlier in a warmer climate. Multiple environmental cues protect plants from growing too early, but to understand how climate change will alter the timing and magnitude of plant growth, experiments need to independently manipulate temperature and snowmelt. Here, we demonstrate that altered seasonality through experimental warming and earlier snowmelt led to earlier plant growth, but the aboveground production response varied among plant functional groups. Earlier snowmelt without warming led to early leaf emergence, but often slowed the rate of leaf expansion and had limited effects on aboveground production. Experimental warming alone had small and inconsistent effects on aboveground phenology, while the effect of the combined treatment resembled that of early snowmelt alone. Experimental warming led to greater aboveground production among the graminoids, limited changes among deciduous shrubs and decreased production in one of the dominant evergreen shrubs. As a result, we predict that early onset of the growing season may favour early growing plant species, even those that do not shift the timing of leaf expansion. PMID:27075181

  15. Questa baseline and pre-mining ground-water quality investigation. 2. Low-flow (2001) and snowmelt (2002) synoptic/tracer water chemistry for the Red River, New Mexico

    USGS Publications Warehouse

    McCleskey, R. Blaine; Nordstrom, D. Kirk; Steiger, Judy I.; Kimball, Briant A.; Verplanck, Philip L.

    2003-01-01

    Water analyses are reported for 259 samples collected from the Red River, New Mexico, and its tributaries during low-flow(2001) and spring snowmelt (2002) tracer studies. Water samples were collected along a 20-kilometer reach of the Red River beginning just east of the town of Red River and ending at the U.S. Geological Survey streamflow-gaging station located east of Questa, New Mexico. The study area was divided into three sections where separate injections and synoptic sampling events were performed during the low-flow tracer study. During the spring snowmelt tracer study, three tracer injections and synoptic sampling events were performed bracketing the areas with the greatest metal loading into the Red River as determined from the low-flow tracer study. The lowflow tracer synoptic sampling events were August 17, 20, and 24, 2001. The synoptic sampling events for the spring snowmelt tracer were March 30, 31, and April 1, 2002. Stream and large inflow water samples were sampled using equal-width and depth-integrated sampling methods and composited into half-gallon bottles. Grab water samples were collected from smaller inflows. Stream temperatures were measured at the time of sample collection. Samples were transported to a nearby central processing location where pH and specific conductance were measured and the samples processed for chemical analyses. Cations, trace metals, iron redox species, and fluoride were analyzed at the U.S. Geological Survey laboratory in Boulder, Colorado. Cations and trace metal concentrations were determined using inductively coupled plasma-optical emission spectrometry and graphite furnace atomic absorption spectrometry. Arsenic concentrations were determined using hydride generation atomic absorption spectrometry, iron redox species were measured using ultraviolet-visible spectrometry, and fluoride concentrations were determined using an ion-selective electrode. Alkalinity was measured by automated titration, and sulfate

  16. Statistical summaries of streamflow in Oklahoma through 1999

    USGS Publications Warehouse

    Tortorelli, R.L.

    2002-01-01

    Statistical summaries of streamflow records through 1999 for gaging stations in Oklahoma and parts of adjacent states are presented for 188 stations with at least 10 years of streamflow record. Streamflow at 113 of the stations is regulated for specific periods. Data for these periods were analyzed separately to account for changes in streamflow due to regulation by dams or other human modification of streamflow. A brief description of the location, drainage area, and period of record is given for each gaging station. A brief regulation history also is given for stations with a regulated streamflow record. This descriptive information is followed by tables of mean annual discharges, magnitude and probability of exceedance of annual high flows, magnitude and probability of exceedance of annual instantaneous peak flows, durations of daily mean flow, magnitude and probability of non-exceedance of annual low flows, and magnitude and probability of non-exceedance of seasonal low flows.

  17. Ecohydrologic Response of a Wetland Indicator Species to Climate Change and Streamflow Regulation: A Conceptual Model

    NASA Astrophysics Data System (ADS)

    Ward, E. M.; Gorelick, S.

    2015-12-01

    The Peace-Athabasca Delta ("Delta") in northeastern Alberta, Canada, is a UNESCO World Heritage Site and a Ramsar Wetland of International Importance. Delta ecohydrology is expected to respond rapidly to upstream water demand and climate change, with earlier spring meltwater, decreased springtime peak flow, and a decline in springtime ice-jam flooding. We focus on changes in the population and distribution of muskrat (Ondatra zibethicus), an ecohydrologic indicator species. We present a conceptual model linking hydrology and muskrat ecology. Our conceptual model links seven modules representing (1) upstream water demand, (2) streamflow and snowmelt, (3) floods, (4) the water balance of floodplain lakes, (5) muskrat habitat suitability, (6) wetland vegetation, and (7) muskrat population dynamics predicted using an agent-based model. Our goal is to evaluate the effects of different climate change and upstream water demand scenarios on the abundance and distribution of Delta muskrat, from present-2100. Moving from the current conceptual model to a predictive quantitative model, we will rely on abundant existing data and Traditional Ecological Knowledge of muskrat and hydrology in the Delta.

  18. Streamflow, Infiltration, and Ground-Water Recharge at Abo Arroyo, New Mexico

    USGS Publications Warehouse

    Stewart-Deaker, Amy E.; Stonestrom, David A.; Moore, Stephanie J.

    2007-01-01

    Abo Arroyo, an ephemeral tributary to the Rio Grande, rises in the largest upland catchment on the eastern side of the Middle Rio Grande Basin (MRGB). The 30-kilometer reach of channel between the mountain front and its confluence with the Rio Grande is incised into basin-fill sediments and separated from the regional water table by an unsaturated zone that reaches 120 meters thick. The MRGB portion of the arroyo is dry except for brief flows generated by runoff from the upland catchment. Though brief, ephemeral flows provide a substantial fraction of ground-water recharge in the southeastern portion of the MRGB. Previous estimates of average annual recharge from Abo Arroyo range from 1.3 to 21 million cubic meters. The current study examined the timing, location, and amount of channel infiltration using streamflow data and environmental tracers during a four-year period (water years 1997?2000). A streamflow-gaging station (?gage?) was installed in a bedrock-controlled reach near the catchment outlet to provide high-frequency data on runoff entering the basin. Streamflow at the gage, an approximate bound on potential tributary recharge to the basin, ranged from 0.8 to 15 million cubic meters per year. Storm-generated runoff produced about 98 percent of the flow in the wettest year and 80 percent of the flow in the driest year. Nearly all flows that enter the MRGB arise from monsoonal storms in July through October. A newly developed streambed temperature method indicated the presence and duration of ephemeral flows downstream of the gage. During the monsoon season, abrupt downward shifts in streambed temperatures and suppressed diurnal ranges provided generally clear indications of flow. Streambed temperatures during winter showed that snowmelt is also effective in generating channel infiltration. Controlled infiltration experiments in dry arroyo sediments indicated that most ephemeral flow is lost to seepage before reaching the Rio Grande. Streambed temperature

  19. A regional estimate of postfire streamflow change in California

    NASA Astrophysics Data System (ADS)

    Bart, Ryan R.

    2016-02-01

    The effect of fire on annual streamflow has been examined in numerous watershed studies, with some studies observing postfire increases in streamflow while other have observed no conclusive change. Despite this inherent variability in streamflow response, the management of water resources for flood protection, water supply, water quality, and the environment necessitates an understanding of postfire effects on streamflow at regional scales. In this study, the regional effect of wildfire on annual streamflow was investigated using 12 paired watersheds in central and southern California. A mixed model was used to pool and statistically examine the combined paired-watershed data, with emphasis on the effects of percentage area burned, postfire recovery of vegetation, and postfire wetness conditions on postfire streamflow change. At a regional scale, postfire annual streamflow increased 134% (82%-200%) during the first postfire year assuming 100% area burned and average annual wetness conditions. Postfire response decreased with lower percentages of percentage area burned and during subsequent years as vegetation recovered following fire. Annual streamflow response to fire was found to be sensitive to annual wetness conditions, with postfire response being smallest during dry years, greatest during wet years, and slowly decreasing during very wet years. These findings provide watershed managers with a first-order estimate for predicting postfire streamflow response in both gauged and ungauged watersheds.

  20. Assessing streamflow sensitivity to variations in glacier mass balance

    USGS Publications Warehouse

    O'Neel, Shad; Hood, Eran; Arendt, Anthony; Sass, Louis

    2014-01-01

    The purpose of this paper is to evaluate relationships among seasonal and annual glacier mass balances, glacier runoff and streamflow in two glacierized basins in different climate settings. We use long-term glacier mass balance and streamflow datasets from the United States Geological Survey (USGS) Alaska Benchmark Glacier Program to compare and contrast glacier-streamflow interactions in a maritime climate (Wolverine Glacier) with those in a continental climate (Gulkana Glacier). Our overall goal is to improve our understanding of how glacier mass balance processes impact streamflow, ultimately improving our conceptual understanding of the future evolution of glacier runoff in continental and maritime climates.

  1. Drivers influencing streamflow changes in the Upper Turia basin, Spain.

    PubMed

    Salmoral, Gloria; Willaarts, Bárbara A; Troch, Peter A; Garrido, Alberto

    2015-01-15

    Many rivers across the world have experienced a significant streamflow reduction over the last decades. Drivers of the observed streamflow changes are multiple, including climate change (CC), land use and land cover changes (LULCC), water transfers and river impoundment. Many of these drivers inter-act simultaneously, making it difficult to discern the impact of each driver individually. In this study we isolate the effects of LULCC on the observed streamflow reduction in the Upper Turia basin (east Spain) during the period 1973-2008. Regression models of annual streamflow are fitted with climatic variables and also additional time variant drivers like LULCC. The ecohydrological model SWAT is used to study the magnitude and sign of streamflow change when LULCC occurs. Our results show that LULCC does play a significant role on the water balance, but it is not the main driver underpinning the observed reduction on Turia's streamflow. Increasing mean temperature is the main factor supporting increasing evapotranspiration and streamflow reduction. In fact, LULCC and CC have had an offsetting effect on the streamflow generation during the study period. While streamflow has been negatively affected by increasing temperature, ongoing LULCC have positively compensated with reduced evapotranspiration rates, thanks to mainly shrubland clearing and forest degradation processes. These findings are valuable for the management of the Turia river basin, as well as a useful approach for the determination of the weight of LULCC on the hydrological response in other regions. PMID:25115604

  2. Calibration procedure for a daily flow model of small watersheds with snowmelt runoff in the Green River coal region of Colorado

    USGS Publications Warehouse

    Norris, J.M.; Parker, R.S.

    1985-01-01

    A calibration procedure was developed for the U.S. Geological Survey 's Precipitation-Runoff Modeling System for watersheds in which snowmelt is the major contributor to runoff. The model uses daily values of air temperature and precipitation as input and the output is mean daily discharge. The procedure appears sufficient to calibrate both streamflow volume and the timing of mean daily discharge if other model parameters are reasonably estimated. Model structure and sensitivity analysis suggest that one of the most important parameters is the available water-holding capacity of the soil (SMAX). Changing this parameter through a series of iterations, the calibration procedure minimizes the error between observed and predicted annual discharge. The calibration suggests that the single parameter SMAX may be sufficient for optimizing both the volumes and the timing of runoff, assuming other model parameters are adequately estimated. Additional optimization on parameters sensitive to timing does not appear to improve prediction. This indicates that these parameters were estimated accurately prior to calibration. Further investigation is needed on more watersheds to determine SMAX 's ability to calibrate volume and timing with a constant set of other model parameter values. (USGS)

  3. Elevation-dependent controls on snowmelt partitioning and vegetation response inferred from satellite observations

    NASA Astrophysics Data System (ADS)

    Molotch, N. P.; Guan, B.; Trujillo, E.

    2012-12-01

    In many mountainous regions snowmelt is a primary driver of hydrological and ecological processes. The timing and magnitude of snowmelt influences the partitioning of water into hydrological pathways such as evapotranspiration, overland flow, and ground water recharge. This partitioning dramatically impacts ecosystem services by altering water availability in the root zone during the spring transition and throughout the growing season. To improve knowledge of the relationships between snowmelt timing, hydrological flowpaths, and vegetation response, we analyzed the effect of snowmelt timing on runoff production and vegetation greenness in montane environments of the Western United States. The analysis combines yearly peak NDVI derived from the Global Inventory Modeling and Mapping Studies (GIMMS), MODIS-based NDVI observations, and estimates of snowpack distribution from ground stations and remote sensing. In this regard, we show that the strongest temporal relationships between snowmelt timing and vegetation greenness are obtained for the middle elevation range between 2000 m and 2600 m (R-squared values greater than 0.5) with significantly weaker relationships above this region. This finding suggests a switch from water limitations at the lower elevation to energy limitations at the highest elevations. Complimentary spatial analyses indicate that the timing of snowmelt also shows a statistically significant relationship with the spatial distribution of forest greening for individual years (R-squared ~ 0.3). These results indicate that runoff production from middle elevations may be significantly lower than higher elevations as longer growing seasons and higher potential evapotranspiration at lower elevations maintain soil moisture deficits. These results indicate that the sensitivity of runoff generation, forest greening, and carbon uptake to changes in climate may exhibit tipping points associated with elevation.

  4. Processes regulating watershed chemical export during snowmelt, fraser experimental forest, Colorado

    USGS Publications Warehouse

    Stottlemyer, R.

    2001-01-01

    In the Central Rocky Mountains, snowfall dominates precipitation. Airborne contaminants retained in the snowpack can affect high elevation surface water chemistry during snowmelt. At the Fraser Experimental Forest (FEF), located west of the Continental Divide in Central Colorado, snowmelt dominates the annual hydrograph, and accounts for >95% of annual stream water discharge. During the winters of 1989-1993, we measured precipitation inputs, snowpack water equivalent (SWE) and ion content, and stream water chemistry every 7-10 days along a 3150-3500 m elevation gradient in the subalpine and alpine Lexen Creek watershed. The study objectives were to (1) quantify the distribution of SWE and snowpack chemical content with elevation and aspect, (2) quantify snowmelt rates, temperature of soil, snowpack, and air with elevation and aspect, and (3) use change in upstream-downstream water chemistry during snowmelt to better define alpine and subalpine flowpaths. The SWE increased with elevation (P - 3??C) temperatures throughout winter which resulted in significant snowpack ion loss. By snowpack PWE in mid May, the snowpack had lost almost half the cumulative precipitation H+, NH4+, and SO42- inputs and a third of the NO3- input. Windborne soil particulate inputs late in winter increased snowpack base cation content. Variation in subalpine SWE and snowpack ion content with elevation and aspect, and wind redistribution of snowfall in the alpine resulted in large year-to-year differences in the timing and magnitude of SWE, PWE, and snowpack ion content. The alpine stream water ion concentrations changed little during snowmelt indicating meltwater passed quickly through surface porous soils and was well mixed before entering the stream. Conversely, subalpine stream water chemistry was diluted during snowmelt suggesting much melt water moved to the stream as shallow subsurface lateral flow. Published by Elsevier Science B.V.

  5. Inorganic nitrogen and microbial biomass dynamics before and during spring snowmelt

    USGS Publications Warehouse

    Brooks, P.D.; Williams, M.W.; Schmidt, S.K.

    1998-01-01

    Recent work in seasonally snow covered ecosystems has identified thawed soil and high levels of heterotrophic activity throughout the winter under consistent snow cover. We performed measurements during the winter of 1994 to determine how the depth and timing of seasonal snow cover affect soil microbial populations, surface water NO3/- loss during snowmelt, and plant N availability early in the growing season. Soil under early accumulating, consistent snow cover remained thawed during most of the winter and both microbial biomass and soil inorganic N pools gradually increased under the snowpack. At the initiation of snowmelt, microbial biomass N pools increased from 3.0 to 5.9 g N m-2, concurrent with a decrease in soil inorganic N pools. During the latter stages of snowmelt, microbial biomass N pools decreased sharply without a concurrent increase in inorganic N pools or significant leaching losses. In contrast, soil under inconsistent snow cover remained frozen during most of the winter. During snowmelt, microbial biomass initially increased from 1.7 to 3.1 g N m-2 and then decreased as sites became snow-free. In contrast to smaller pool sizes, NO3/-export during snowmelt from the inconsistent snow cover sites of 1.14 (??0.511) g N m-2 was significantly greater (p < 0.001) than the 0.27 (??0.16) g N m-2 exported from sites with consistent snow cover. These data suggest that microbial biomass in consistently snow-covered soil provides a significant buffer limiting the export of inorganic N to surface water during snowmelt. However, this buffer is very sensitive to changes in snowpack regime. Therefore, interannual variability in the timing and depth of snowpack accumulation may explain the year to year variability in inorganic N concentrations in surface water these ecosystems.

  6. Time-lapse Measurements of Electrical Resistivities to Characterise Snowmelt Infiltration Patterns

    NASA Astrophysics Data System (ADS)

    French, H. K.; Du Saire, M.; Binley, A.; Baker, J.

    2006-12-01

    During snowmelt Oslo airport has on repeated occations experienced the formation of large meltwater ponds due to impermeable ice forming below the snowcover. The airport is situated on a large glacial outwash plane with coarse sandy gravely sediments, hence the area normaly has a high infiltration capacity. Focussed infiltration can cause fast transport of contaminants to the groundwater, hence improved understanding of the processes determining where and how the focussed infiltration takes place is important. Previously the melting process has been monitored successfully on a small scale (4 m2) using a two dimensional grid of permanently installed electrodes (French and Binley, 2004). In the present work snowmelt infiltration was monitored by time-lapse measurements of electrical resistivity using grounded electrodes on 4 and 20 m2 plots and a capacitively coupled resistivity system (Ohmmapper, Geometrics) on a larger scale. While the smaller scale systems provide 3D images the capacitively coupled system was used to monitor changes in two dimensional vertical sections in a retention pond adjacent to one of the runways. The area covered by 4 lines was 170 m by 340 m. The initial data were collected late in the spring (2006) during the final stages of the snowmelt. The lines were repeated later in the year when the soil profile was dryer. The lines show good consistency in the description of the general geology of the subsurface and the time-lapse changes describe the infiltration pattern that occurred during snowmelt and subsequent drainage. The surveys provide useful information about the differences in spatial distribution of snowmelt infiltration at different scales. And there are good indications that capacitively coupled resistivity surveys can be used to describe infiltration processes at relatively large spacio-temporal scales. References French, H. and A. Binley, 2004, Snowmelt infiltration: monitoring temporal and spatial variability using time- lapse

  7. Experimental measurement and modeling of snow accumulation and snowmelt in a mountain microcatchment

    NASA Astrophysics Data System (ADS)

    Danko, Michal; Krajčí, Pavel; Hlavčo, Jozef; Kostka, Zdeněk; Holko, Ladislav

    2016-04-01

    Fieldwork is a very useful source of data in all geosciences. This naturally applies also to the snow hydrology. Snow accumulation and snowmelt are spatially very heterogeneous especially in non-forested, mountain environments. Direct field measurements provide the most accurate information about it. Quantification and understanding of processes, that cause these spatial differences are crucial in prediction and modelling of runoff volumes in spring snowmelt period. This study presents possibilities of detailed measurement and modeling of snow cover characteristics in a mountain experimental microcatchment located in northern part of Slovakia in Western Tatra mountains. Catchment area is 0.059 km2 and mean altitude is 1500 m a.s.l. Measurement network consists of 27 snow poles, 3 small snow lysimeters, discharge measurement device and standard automatic weather station. Snow depth and snow water equivalent (SWE) were measured twice a month near the snow poles. These measurements were used to estimate spatial differences in accumulation of SWE. Snowmelt outflow was measured by small snow lysimeters. Measurements were performed in winter 2014/2015. Snow water equivalent variability was very high in such a small area. Differences between particular measuring points reached 600 mm in time of maximum SWE. The results indicated good performance of a snow lysimeter in case of snowmelt timing identification. Increase of snowmelt measured by the snow lysimeter had the same timing as increase in discharge at catchment's outlet and the same timing as the increase in air temperature above the freezing point. Measured data were afterwards used in distributed rainfall-runoff model MIKE-SHE. Several methods were used for spatial distribution of precipitation and snow water equivalent. The model was able to simulate snow water equivalent and snowmelt timing in daily step reasonably well. Simulated discharges were slightly overestimated in later spring.

  8. Evaluation of streamflow traveltime and streamflow gains and losses along the lower Purgatoire River, southeastern Colorado, 1984-92

    USGS Publications Warehouse

    Dash, R.G.; Edelmann, P.R.

    1997-01-01

    Traveltime and gains and losses within a stream are important basic characteristics of streamflow. The lower Purgatoire River flows more than 160 river miles from Trinidad to the Arkansas River near Las Animas. A better knowledge of streamflow traveltime and streamflow gains and losses along the lower Purgatoire River would enable more informed management decisions about the availability of water supplies for irrigation use in southeastern Colorado. In 1994-95, the U.S.\\x11Geological Survey, in cooperation with the Purgatoire River Water Conservancy District and the Arkansas River Compact Administration, evaluated streamflow traveltime and estimated streamflow gains and losses using historical surface-water records. Traveltime analyses were used along the lower Purgatoire River to determine when streamflows would arrive at selected downstream sites. The substantial effects of diversions for irrigation and unmeasured return flows in the most upstream reach of the river prevented the tracking of streamflow through reach\\x111. Therefore, the estimation of streamflow traveltime for the 60.6 miles of river downstream from Trinidad could not be made.Hourly streamflow data from 1990 through 1994 were used to estimate traveltimes of more than 30 streamflow events for about 100 miles of the lower Purgatoire River. In the middle reach of the river, the traveltime of streamflow for the 40.1\\x11miles ranged from about 11 to about 47\\x11hours, and in the lower reach of the river, traveltime for the 58.5 miles ranged from about 6 to about 61 hours.Traveltime in the river reaches generally increased as streamflow decreased, but also varied for a specific streamflow in both reaches. Streamflow gains and losses were estimated using daily streamflow data at the upstream and downstream sites, available tributary inflow data, and daily diversion data. Differences between surface-water inflows and surface-water outflows in a reach determined the quantity of water gained or lost. In

  9. The Safe Drinking Water Act First 180 Days

    ERIC Educational Resources Information Center

    Lehr, Jay H.

    1975-01-01

    The Safe Drinking Water Act protects our drinking and ground water resources. The Water Advisory Council interprets and implements the law. Implementation principles include high priorities for public health, cost considerations, state and local participation, environmental impact, decentralized decision making, and use of federal and state…

  10. Assimilation of AATSR, MERIS and MODIS data in the snowmelt runoff model (SRM) on the upper Rio Grande (USA)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current efforts for simulating or forecasting snowmelt are time-consuming and laborious; the AWARE project (A tool for monitoring and forecasting Available WAter REsource in mountain environments) has been motivated by the urgent need to facilitate the prediction of medium-term flows from snowmelt f...

  11. Calculating weighted estimates of peak streamflow statistics

    USGS Publications Warehouse

    Cohn, Timothy A.; Berenbrock, Charles; Kiang, Julie E.; Mason, Jr., Robert R.

    2012-01-01

    According to the Federal guidelines for flood-frequency estimation, the uncertainty of peak streamflow statistics, such as the 1-percent annual exceedance probability (AEP) flow at a streamgage, can be reduced by combining the at-site estimate with the regional regression estimate to obtain a weighted estimate of the flow statistic. The procedure assumes the estimates are independent, which is reasonable in most practical situations. The purpose of this publication is to describe and make available a method for calculating a weighted estimate from the uncertainty or variance of the two independent estimates.

  12. Hydrologic response to modeled snowmelt input in alpine catchments in the Southwestern United States

    NASA Astrophysics Data System (ADS)

    Driscoll, J. M.; Molotch, N. P.; Jepsen, S. M.; Meixner, T.; Williams, M. W.; Sickman, J. O.

    2012-12-01

    Snowmelt from high elevation catchments is the primary source of water resources in the Southwestern United States. Timing and duration of snowmelt and resulting catchment response can show the physical and chemical importance of storage at the catchment scale. Storage of waters in subsurface materials provides a physical and chemical buffer to hydrologic input variability. We expect the hydrochemistry of catchments with less storage capacity will more closely reflect input waters than a catchment with more storage and therefore more geochemical evolution of waters. Two headwater catchments were compared for this study; Emerald Lake Watershed (ELW) in the southern Sierra Nevada and Green Lake 4 (GL4) in the Colorado Front Range. These sites have geochemically similar granitic terrane, and negligible evaporation and transpiration due to their high-elevation setting. Eleven years of data (1996-2006) from spatially-distributed snowmelt models were spatially and temporally aggregated to generate daily values of snowmelt volume for each catchment area. Daily storage flux was calculated as the difference between snowmelt input and catchment outflow at a daily timestep, normalized to the catchment area. Daily snowmelt values in GL4 are more consistent (the annual standard deviation ranged from 0.19 to 0.76 cm) than the daily snowmelt in ELW (0.60 to 1.04 cm). Outflow follows the same trend, with an even narrower range of standard deviations from GL4 (0.27 to 0.54 cm) compared to the standard deviation of outflow in ELW (0.38 to 0.98 cm). The dampening of the input variability could be due to storage in the catchment; the larger effect would mean a larger storage capacity in the catchment. Calculations of storage flux (the input snowmelt minus the output catchment discharge) show the annual sum of water into storage in ELW ranges from -0.9200 to 1.1124 meters, in GL4 the ranger is narrower, from -0.655 to 0.0992 meters. Cumulative storage for each year can be negative

  13. Adjusted Streamflow and Storage 1928-1989 : with Listings of Historical Streamflow, Summation of Storage Change and Adjusted Streamflow : Columbia River and Coastal Basins.

    SciTech Connect

    A.G. Crook Company

    1993-04-01

    The development of irrigation projects since the 1830's and the construction of major dams and reservoirs since the early 1900's have altered substantially the natural streamflow regimen of the Columbia River and its tributaries. As development expanded a multipurpose approach to streamflow regulation evolved to provide flood control, irrigation, hydropower generation, navigation, recreation, water quality enhancement, fish and wildlife, and instream flow maintenance. The responsible agencies use computer programs to determine the effects of various alternative system regulations. This report describes the development of the streamflow data that these computer programs use.

  14. A Tree-Ring Derived Reconstruction of Regionalized Low-Flow Season Streamflow for Susceptible Watersheds in South Coastal British Columbia, Canada.

    NASA Astrophysics Data System (ADS)

    Coulthard, B. L.; Smith, D. J.

    2014-12-01

    Rising winter air temperatures, snowpack declines, and warmer and drier summers have resulted in an increase in the frequency and severity of late-summer low-flow events across south coastal British Columbia. Negative impacts, particularly those associated with deteriorating water quality, decreased water supply for hydroelectric power generation, and the survivorship of migrating Pacific salmon, have been observed and are expected to intensify. It is not known whether these earlier, longer, and/or lower low-flows are anomalous relative to historical streamflow patterns since available gauged flow data is restricted to the last five decades. We used networks of high-elevation tree-ring data to model historical low-flow (late-summer) season streamflow regionalized across a group of hydrologically similar watersheds that were identified as susceptible to low-flow events. Our approach contrasts with typical dendrohydrological approaches in that the study watersheds are relatively small in size, and we have not employed moisture-limited tree-ring records as model predictors. In these rainfall-dominated streamflow regimes, late-summer discharge is driven by a combination of persisting snowmelt-derived inputs and variations in summer temperature. We used correlation analysis to prescreen a large pool of tree-ring chronologies as candidate model predictors, retaining those whose annual radial growth is limited by variability in those climate variables driving low-flow season discharge. We conducted principal components analysis on the retained chronologies to derive a set of tree-ring based predictors, which were entered into a stepwise multiple linear regression model to estimate historical regionalized low-flow season flows. Our model explains approximately 60% of streamflow variance, elucidates the frequencies and magnitudes of past low-flow episodes not represented within the instrumental record, and provides a historical context for contemporary shifts in the

  15. CHARACTERISTICS OF ACIDITY AND MAJOR ION CONCENTRATION OF SNOWFALL, SNOWPACK AND SNOWMELT WATER IN THE TEMPERATE SNOW AREA

    NASA Astrophysics Data System (ADS)

    Asaoka, Yoshihiro; Takeuchi, Yukari

    This paper describes the acidity and main ion concentration of snowfall, snowpack and snowmelt water in the temperate snow area. In order to understand the variation of snow water quality and its relationship among snow, snowpack and snowmelt, snow monitoring and chemical measurement were conducted from December 2008 to March 2009 at Tohkamachi experiment site. As a result, the both of snowfall and snowmelt were high acidity and their average were around 4.6 and 5.0, individually. However, high frequencies of rainfall and snowmelt occurrence during winter decrease the high acidity of snowpack and snowmelt water since they prevent the chemical matter from depositing in the snowpack layer. Moreover, it is suspected that the soil component from Eurasia continent contained in the snow particle also decrease the high acidity of snowfall and snowpack.

  16. Sensitivity of northern Sierra Nevada streamflow to climate change

    USGS Publications Warehouse

    Duell, L.F.W.

    1994-01-01

    The sensitivity of streamflow to climate change was investigated in the American, Carson, and Truckee River Basins, California and Nevada. Nine gaging stations were used to represent streamflow in the basins. Annual models were developed by regressing 1961-1991 streamflow data on temperature and precipitation. Climate-change scenarios were used as inputs to the models to determine streamflow sensitivities. Climate-change scenarios were generated from historical time series by modifying mean temperatures by a range of +4??C to -4??C and total precipitation by a range of +25 percent to -25 percent. Results show that streamflow on the warmer, lower west side of the Sierra Nevada generally is more sensitive to temperature and percipitation changes than is streamflow on the colder, higher east side. A 2??C rise in temperature and a 25-percent decrease in precipitation results in streamflow decreases of 56 percent on the American River and 25 percent on the Carson River. A 2??C decline in temperature and a 25-percent increase in precipitation results in streamflow increases of 102 percent on the American River and 22 percent on the Carson River.

  17. ECOLOGICALLY-RELEVANT QUANTIFICATION OF STREAMFLOW REGIMES IN WESTERN STREAMS

    EPA Science Inventory

    This report describes the rationale for and application of a protocol for estimation of ecologically-relevant streamflow metrics that quantify streamflow regime for ungaged sites subject to a range of human impact. The analysis presented here is focused on sites sampled by the U....

  18. Climatic Fluctuations and the Timing of West Coast Streamflow.

    NASA Astrophysics Data System (ADS)

    Aguado, E.; Cayan, D.; Riddle, L.; Roos, M.

    1992-12-01

    Since about 1950 there has been a trend in the California Sierra Nevada toward a decreasing portion of the total annual streamflow occurring during April through July, while the streamflow during autumn and winter has increase. This trend not only has important ramifications with regard to water management, it also brings up the question of whether this represents a shift toward earlier release of the snowpack resulting from greenhouse warming. Therefore, the observed record has been examined in terms of relative influences of temperature and precipitation anomalies on the timing of streamflow in this region. To carry out this study, the fraction of annual streamflow (called the fractional streamflow) occurring in November-January (NDJ), February-April (FMA), and May-July (MJJ) at low, medium, and high elevation basins in California and 0regon was examined. Linear regression models were used to relate precipitation and temperature to the fractional streamflow at the three elevations for each season. Composites of monthly temperature and precipitation were employed to further examine the fractional streanflow in its high and low tercile extremes. Long time series of climatic and hydrologic data were also looked at to infer the causes in the trend toward earlier runoff.For the low-elevation basins, there is a dominant influence of precipitation on seasonal fractional streamflow. Middle-elevation basins exhibit a longer memory of precipitation and temperature in relation to their fractional stream-flow. In-season precipitation is still the most important influence upon NDJ and FMA fractional streamflow; however, the influence of temperature in melting the snowpack is seen on MJJ fractional streamflow, whose strongest influence is FMA temperature. At higher elevation prior-season precipitation exerts a greater influence than at low and middle elevations, and seasonal temperature anomalies have an effect on all seasonal streamflow fractions.There are several causes for

  19. Dry season streamflow persistence in seasonal climates

    NASA Astrophysics Data System (ADS)

    Dralle, David N.; Karst, Nathaniel J.; Thompson, Sally E.

    2016-01-01

    Seasonally dry ecosystems exhibit periods of high water availability followed by extended intervals during which rainfall is negligible and streamflows decline. Eventually, such declining flows will fall below the minimum values required to support ecosystem functions or services. The time at which dry season flows drop below these minimum values (Q*), relative to the start of the dry season, is termed the "persistence time" (). The persistence time determines how long seasonal streams can support various human or ecological functions during the dry season. In this study, we extended recent work in the stochastic hydrology of seasonally dry climates to develop an analytical model for the probability distribution function (PDF) of the persistence time. The proposed model accurately captures the mean of the persistence time distribution, but underestimates its variance. We demonstrate that this underestimation arises in part due to correlation between the parameters used to describe the dry season recession, but that this correlation can be removed by rescaling the flow variables. The mean persistence time predictions form one example of the broader class of streamflow statistics known as crossing properties, which could feasibly be combined with simple ecological models to form a basis for rapid risk assessment under different climate or management scenarios.

  20. Spring onset in the Sierra Nevada: When is snowmelt independent of elevation?

    USGS Publications Warehouse

    Lundquist, J.D.; Cayan, D.R.; Dettinger, M.D.

    2004-01-01

    Short-term climate and weather systems can have a strong influence on mountain snowmelt, sometimes overwhelming the effects of elevation and aspect. Although most years exhibit a spring onset that starts first at lowest and moves to highest elevations, in spring 2002, flow in a variety of streams within the Tuolumne and Merced River basins of the southern Sierra Nevada all rose synchronously on 29 March. Flow in streams draining small high-altitude glacial subcatchments rose at the same time as that draining much larger basins gauged at lower altitudes, and streams from north- and south-facing cirques rose and fell together. Historical analysis demonstrates that 2002 was one among only 8 yr with such synchronous flow onsets during the past 87 yr, recognized by having simultaneous onsets of snowmelt at over 70% of snow pillow sites, having discharge in over 70% of monitored streams increase simultaneously, and having temperatures increase over 12??C within a 5-day period. Synchronous springs tend to begin with a low pressure trough over California during late winter, followed by the onset of a strong ridge and unusually warm temperatures. Synchronous springs are characterized by warmer than average winters and cooler than average March temperatures in California. In the most elevation-dependent, nonsynchronous years, periods of little or no storm activity, with warmer than average March temperatures, precede the onset of spring snowmelt, allowing elevation and aspect to influence snowmelt as spring arrives gradually. ?? 2004 American Meteorological Society.

  1. An Analysis of Climate Variability and Snowmelt Mechanisms inMountainous Regions

    SciTech Connect

    jimingjin@lbl.gov

    2003-09-26

    The impacts of snowpack on climate variability and themechanisms of snowmelt over the Sierra Nevada, California-Nevadamountainous region was studied using the Penn State-National Center forAtmospheric Research fifth-generation Mesoscale Model (MM5) driven by6-hour reanalysis data from the National Centers for EnvironmentalPrediction. The analyses of a one-way nested 48 km to 12 km model runduring the 1998 snowmelt season (April - June) shows that snowpack isunderestimated when there is stronger precipitation and highertemperature. Model resolution and simulated snowpack are found to affectthe temperature and precipitation. Coarser resolution underestimates thetopographic elevation in the Sierra Nevada, increasing the surface airtemperature and precipitation in light of the lapse rate and the rainshadow effect. An observed daily snowpack dataset, assimilated to MM5,reduces the warm bias, because the energy used to increase temperature ina model run without assimilated snow is consumed by snowmelt. The cooledsurface leads to a more stable simulated atmosphere, leading to areduction in the exaggerated precipitation. An underestimated surfacealbedo weakly contributes to the stronger snowmelt. A more realisticphysically-based land-surface model with sophisticated snow andvegetation physics driven by the MM5 output is shown to significantlyimprove the snowpack simulation.

  2. Sensitivity of the snowmelt runoff model to underestimates of remotely sensed snow covered area

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three methods for estimating snow covered area (SCA) from Terra MODIS data were used to derive conventional depletion curves for input to the Snowmelt Runoff Model (SRM). We compared the MOD10 binary and fractional snow cover products and a method for estimating sub-pixel snow cover using spectral m...

  3. Evaluation of snowmelt simulation in the Weather Research and Forecasting model

    NASA Astrophysics Data System (ADS)

    Jin, Jiming; Wen, Lijuan

    2012-05-01

    The objective of this study is to better understand and improve snowmelt simulations in the advanced Weather Research and Forecasting (WRF) model by coupling it with the Community Land Model (CLM) Version 3.5. Both WRF and CLM are developed by the National Center for Atmospheric Research. The automated Snow Telemetry (SNOTEL) station data over the Columbia River Basin in the northwestern United States are used to evaluate snowmelt simulations generated with the coupled WRF-CLM model. These SNOTEL data include snow water equivalent (SWE), precipitation, and temperature. The simulations cover the period of March through June 2002 and focus mostly on the snowmelt season. Initial results show that when compared to observations, WRF-CLM significantly improves the simulations of SWE, which is underestimated when the release version of WRF is coupled with the Noah and Rapid Update Cycle (RUC) land surface schemes, in which snow physics is oversimplified. Further analysis shows that more realistic snow surface energy allocation in CLM is an important process that results in improved snowmelt simulations when compared to that in Noah and RUC. Additional simulations with WRF-CLM at different horizontal spatial resolutions indicate that accurate description of topography is also vital to SWE simulations. WRF-CLM at 10 km resolution produces the most realistic SWE simulations when compared to those produced with coarser spatial resolutions in which SWE is remarkably underestimated. The coupled WRF-CLM provides an important tool for research and forecasts in weather, climate, and water resources at regional scales.

  4. Stream Nitrogen Inputs Reflect Groundwater Across a Snowmelt-Dominated Montane to Urban Watershed.

    PubMed

    Hall, Steven J; Weintraub, Samantha R; Eiriksson, David; Brooks, Paul D; Baker, Michelle A; Bowen, Gabriel J; Bowling, David R

    2016-02-01

    Snowmelt dominates the hydrograph of many temperate montane streams, yet little work has characterized how streamwater sources and nitrogen (N) dynamics vary across wildland to urban land use gradients in these watersheds. Across a third-order catchment in Salt Lake City, Utah, we asked where and when groundwater vs shallow surface water inputs controlled stream discharge and N dynamics. Stream water isotopes (δ(2)H and δ(18)O) reflected a consistent snowmelt water source during baseflow. Near-chemostatic relationships between conservative ions and discharge implied that groundwater dominated discharge year-round across the montane and urban sites, challenging the conceptual emphasis on direct stormwater inputs to urban streams. Stream and groundwater NO3(-) concentrations remained consistently low during snowmelt and baseflow in most montane and urban stream reaches, indicating effective subsurface N retention or denitrification and minimal impact of fertilizer or deposition N sources. Rather, NO3(-) concentrations increased 50-fold following urban groundwater inputs, showing that subsurface flow paths potentially impact nutrient loading more than surficial land use. Isotopic composition of H2O and NO3(-) suggested that snowmelt-derived urban groundwater intercepted NO3(-) from leaking sewers. Sewer maintenance could potentially mitigate hotspots of stream N inputs at mountain/valley transitions, which have been largely overlooked in semiarid urban ecosystems. PMID:26744921

  5. SPATIAL AND TEMPORAL VARIATIONS IN SNOWMELT DEGREE-DAY FACTORS COMPUTED FROM SNOTEL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The spatial and temporal variation of degree-day melt factors (DDF¿s) computed from SNOTEL data were evaluated for the Upper Rio Grande Basin to improve modeling and forecasting of snowmelt runoff. Data from seven SNOTEL sites in the Upper Rio Grande Basin were analyzed for the 1996-2000 melt seaso...

  6. Impact of Mountain Pine Beetle Infestation on Snowmelt: Variations with Vegetation Structure and Geographical Locations

    NASA Astrophysics Data System (ADS)

    Ni-Meister, W.

    2015-12-01

    The warming climate resulted in the current outbreak of mountain pine beetles (MPB) in western and northwestern US. and Western Canada. Colorado, Wyoming, South Dakota, Nebraska, and British Columbia are also currently experiencing widespread mountain pine beetle infestations. Forest disturbance due to MPB can have a large impact on hydrological processes specifically snow accumulation and snowmelt. In those regions, spring snowmelt is a major water resource and MPB infestations can have a big impact on water resource management. MPB infestations cause forest canopies to gradually diminish over the course of several years, they therefore impact snow interception and radiation balance at snow surface, thus snowmelt. Past studies on this topic have achieved contradicting results. This study focuses on understanding how the impacts of MPB infestations on snow surface radiation balance and snowmelt rates vary with vegetation structure and geographical locations. We selected four sites in northern Colorado and four sites in the Cascade Mountains in Oregon with varying intensities of MPB. Snow Water Equivalent (SWE) data from SNOTEL sites and MPB-caused forest disturbance data extracted from Landsat time series disturbance maps were used for our analysis. Our results show that MPB sites show larger snow accumulation for sites in Colorado and Cascade Mountains. However snowmelt rate varies differently. For sites in Colorado, snow melts faster in the MPB sites than in the healthy forest sites. In contrary, in the Cascade Mountains, snow stays longer in MPB sites than in healthy and undisturbed sites. Our modeling study shows that shortwave radiation is a dominant factor for radiation balance in the mid-latitude region (Colorado). There, MPB infestations lead to increased shortwave radiation and faster snowmelt. However, long wave radiation plays an important role for radiation balance in high latitude areas. MPB infestations decrease longwave radiation and result in snow

  7. The Sensitivity of Soil Moisture in Western U.S. Mountains to Changes in Snowmelt

    NASA Astrophysics Data System (ADS)

    Harpold, A. A.

    2014-12-01

    Snowmelt is the primary water source for human needs and ecosystems services in much of the Western U.S. Regional warming is expected to hasten snow disappearance and reduce snowpacks. The soil water budget strongly mediates the effects of changing snowmelt patterns by storing water and altering is partitioning to evaporation, transpiration, and runoff. This study therefore asked the research question, "Under what conditions was soil water availability coupled to snowmelt magnitudes and timing across Western U.S. mountains?" We posed three potential hypotheses to explain decoupling between soil water availability and snowmelt: 1. Contributions from post-snowmelt rainfall, 2. Longer growing season length and/or greater water demand, and/or 3. Insufficient soil water storage. Using 259 Snow Telemetry (SNOTEL) stations, we showed that the timing of Peak Soil Moisture (PSM) was strongly explained by snow disappearance (Pearson r-value of 0.62). However, differences in the coupling of PSM with DSD were dependent on soil and bedrock type, with well-drained areas having earlier PSM relative to DSD. A second analysis focused on 48 SNOTEL and Soil Climate Analysis Network (SCAN) stations in the Northwest and Intermountain Western U.S. where detailed soil hydraulic properties existed. We found the timing of snow disappearance was a strong influence (p<0.01) on the number of days per year that soil moisture was below wilting point at individual stations, whereas summer precipitation was a weaker predictor. We develop a framework to classify stations into three classes: 1. stations that were not subject to water stress from changing snowmelt patterns over the historical records, 2. stations subject to water stress during poor snowmelt years, and 3. stations that relied on rainfall to avoid water stress across historical records. Our combined results demonstrate that snow disappearance timing is a first-order control on soil water availability across many Western U.S. mountain

  8. Evaluation of the streamflow-gaging network of Alaska in providing regional streamflow information

    USGS Publications Warehouse

    Brabets, Timothy P.

    1996-01-01

    In 1906, the U.S. Geological Survey (USGS) began operating a network of streamflow-gaging stations in Alaska. The primary purpose of the streamflow- gaging network has been to provide peak flow, average flow, and low-flow characteristics to a variety of users. In 1993, the USGS began a study to evaluate the current network of 78 stations. The objectives of this study were to determine the adequacy of the existing network in predicting selected regional flow characteristics and to determine if providing additional streamflow-gaging stations could improve the network's ability to predict these characteristics. Alaska was divided into six distinct hydrologic regions: Arctic, Northwest, Southcentral, Southeast, Southwest, and Yukon. For each region, historical and current streamflow data were compiled. In Arctic, Northwest, and Southwest Alaska, insufficient data were available to develop regional regression equations. In these areas, proposed locations of streamflow-gaging stations were selected by using clustering techniques to define similar areas within a region and by spatial visual analysis using the precipitation, physiographic, and hydrologic unit maps of Alaska. Sufficient data existed in Southcentral and Southeast Alaska to use generalized least squares (GLS) procedures to develop regional regression equations to estimate the 50-year peak flow, annual average flow, and a low-flow statistic. GLS procedures were also used for Yukon Alaska but the results should be used with caution because the data do not have an adequate spatial distribution. Network analysis procedures were used for the Southcentral, Southeast, and Yukon regions. Network analysis indicates the reduction in the sampling error of the regional regression equation that can be obtained given different scenarios. For Alaska, a 10-year planning period was used. One scenario showed the results of continuing the current network with no additional gaging stations and another scenario showed the results

  9. Timing and regional patterns of snowmelt on Antarctic sea ice from passive microwave satellite observations

    NASA Astrophysics Data System (ADS)

    Arndt, Stefanie; Willmes, Sascha; Dierking, Wolfgang; Nicolaus, Marcel

    2016-04-01

    The better understanding of temporal variability and regional distribution of surface melt on Antarctic sea ice is crucial for the understanding of atmosphere-ocean interactions and the determination of mass and energy budgets of sea ice. Since large regions of Antarctic sea ice are covered with snow during most of the year, observed inter-annual and regional variations of surface melt mainly represents melt processes in the snow. It is therefore important to understand the mechanisms that drive snowmelt, both at different times of the year and in different regions around Antarctica. In this study we combine two approaches for observing both surface and volume snowmelt by means of passive microwave satellite data. The former is achieved by measuring diurnal differences of the brightness temperature TB at 37 GHz, the latter by analyzing the ratio TB(19GHz)/TB(37GHz). Moreover, we use both melt onset proxies to divide the Antarctic sea ice cover into characteristic surface melt patterns from 1988/89 to 2014/15. Our results indicate four characteristic melt types. On average, 43% of the ice-covered ocean shows diurnal freeze-thaw cycles in the surface snow layer, resulting in temporary melt (Type A), less than 1% shows continuous snowmelt throughout the snowpack, resulting in strong melt over a period of several days (Type B), 19% shows Type A and B taking place consecutively (Type C), and for 37% no melt is observed at all (Type D). Continuous melt is primarily observed in the outflow of the Weddell Gyre and in the northern Ross Sea, usually 20 days after the onset of temporary melt. Considering the entire data set, snowmelt processes and onset do not show significant temporal trends. Instead, areas of increasing (decreasing) sea-ice extent have longer (shorter) periods of continuous snowmelt.

  10. Changing the seasonality of an Arctic tundra ecosystem: earlier snowmelt and warmer temperatures

    NASA Astrophysics Data System (ADS)

    Steltzer, H.; Weintraub, M. N.; Darrouzet-Nardi, A.; Melle, C.; Segal, A.; Sullivan, P.; Landry, C.; Wallenstein, M. D.

    2010-12-01

    In the Arctic and around the world, earlier plant growth is an indication that warmer temperatures or other global changes are changing the seasonality of the Earth’s ecosystems. To determine how changes in seasonality affect plant life histories and biogeochemical cycles in tussock tundra, we established a factorial experiment that includes two approaches to changing the seasonality of this ecosystem. In early May, we placed radiation absorbing fabric on the snow surface to accelerate the timing of snowmelt. We monitored the rate of snowmelt over a 10 day period and removed the fabric on the 10th day when the accelerated plots were 80% snowfree. Instrument arrays placed in the plots collected daily data that characterize an increase in energy absorption in these snowfree areas over the 4 day period prior to when control areas were snowfree. In addition, when the plots became snowfree we placed open-top-chambers in areas with and without accelerated snowmelt. The chambers increased air temperatures especially during mid-day early in the growing season. The instrument arrays included light sensors to monitor the plant community life history by observing surface greenness. Our results suggest that the plant community initiated growth earlier when snowmelt occurred earlier and that warming speeded the development of the plant canopy. However, plant species’ life history responses to these changes in seasonality were variable. Experimental alteration of the timing of plant life history events will provide a useful tool to examine controls on the seasonality of biogeochemical processes, such as nutrient availability to plants and nutrient limitation of decomposition. Accelerated snowmelt and warmer temperatures in tussock tundra, AK.

  11. Combining a Water Balance Model for Streamflow Simulations with Long Tree-Ring Records to Improve Estimation of Water Resource Variability

    NASA Astrophysics Data System (ADS)

    Saito, L.; Biondi, F.; Salas, J.; Strachan, S.

    2009-12-01

    A widely used approach for extending the relatively brief instrumental record of streamflow and obtaining a paleo perspective on recent hydrological changes is by means of tree-ring records. To date, dendrohydrologists have employed sophisticated regression techniques to extend runoff records, but this empirical approach cannot directly test the influence of watershed factors that alter streamflow independently of climate. We designed a mechanistic watershed model to calculate streamflows at annual time steps using as few inputs as possible. The model was calibrated and verified for the upper reaches of the Walker River, which straddles the boundary between the Sierra Nevada of California and the Great Basin of Nevada. Even though the model incorporated simplified relationships between precipitation and other components of the hydrologic cycle, it predicted water year streamflows with correlations of 0.9 when appropriate precipitation values were used. An expansion of this model for seasonal time steps has been completed through the addition of a snowmelt component. Ongoing work involves using the model to generate streamflows from a 2300-year annual proxy record of precipitation developed using western juniper (Juniperus occidentalis) tree-ring records from the Walker River basin. The main climate signal in the tree-ring chronology is October through September (i.e., water year) precipitation, and this record has already been analyzed with respect to duration, magnitude, and peak of extended dry and wet episodes, including the 1930s drought and the early 1900s pluvial. According to this numerical classification scheme, the most remarkable episode was the mid-1800s drought (1840-'51), followed by two pluvials, at the end of the 7th century (682-692) and at the beginning of the 20th one (1900-'19); the Dust Bowl drought (1927-'36 in this record) was in 73rd position. Therefore, statistics derived from the instrumental record appear to be skewed by a truly unique wet

  12. Comparison of historical streamflows to 2013 Streamflows in the Williamson, Sprague, and Wood Rivers, Upper Klamath Lake Basin, Oregon

    USGS Publications Warehouse

    Hess, Glen W.; Stonewall, Adam J.

    2014-01-01

    In 2013, the Upper Klamath Lake Basin, Oregon, experienced a dry spring, resulting in an executive order declaring a state of drought emergency in Klamath County. The 2013 drought limited the water supply and led to a near-total cessation of surface-water diversions for irrigation above Upper Klamath Lake once regulation was implemented. These conditions presented a unique opportunity to understand the effects of water right regulation on streamflows. The effects of regulation of diversions were evaluated by comparing measured 2013 streamflow with data from hydrologically similar years. Years with spring streamflow similar to that in 2013 measured at the Sprague River gage at Chiloquin from water years 1973 to 2012 were used to define a Composite Index Year (CIY; with diversions) for comparison to measured 2013 streamflows (no diversions). The best-fit 6 years (1977, 1981, 1990, 1991, 1994, and 2001) were used to determine the CIY. Two streams account for most of the streamflow into Upper Klamath Lake: the Williamson and Wood Rivers. Most streamflow into the lake is from the Williamson River Basin, which includes the Sprague River. Because most of the diversion regulation affecting the streamflow of the Williamson River occurred in the Sprague River Basin, and because of uncertainties about historical flows in a major diversion above the Williamson River gage, streamflow data from the Sprague River were used to estimate the change in streamflow from regulation of diversions for the Williamson River Basin. Changes in streamflow outside of the Sprague River Basin were likely minor relative to total streamflow. The effect of diversion regulation was evaluated using the “Baseflow Method,” which compared 2013 baseflow to baseflow of the CIY. The Baseflow Method reduces the potential effects of summer precipitation events on the calculations. A similar method using streamflow produced similar results, however, despite at least one summer precipitation event. The

  13. A past discharge assimilation system for ensemble streamflow forecasts over France - Part 2: Impact on the ensemble streamflow forecasts

    NASA Astrophysics Data System (ADS)

    Thirel, G.; Martin, E.; Mahfouf, J.-F.; Massart, S.; Ricci, S.; Regimbeau, F.; Habets, F.

    2010-08-01

    The use of ensemble streamflow forecasts is developing in the international flood forecasting services. Ensemble streamflow forecast systems can provide more accurate forecasts and useful information about the uncertainty of the forecasts, thus improving the assessment of risks. Nevertheless, these systems, like all hydrological forecasts, suffer from errors on initialization or on meteorological data, which lead to hydrological prediction errors. This article, which is the second part of a 2-part article, concerns the impacts of initial states, improved by a streamflow assimilation system, on an ensemble streamflow prediction system over France. An assimilation system was implemented to improve the streamflow analysis of the SAFRAN-ISBA-MODCOU (SIM) hydro-meteorological suite, which initializes the ensemble streamflow forecasts at Météo-France. This assimilation system, using the Best Linear Unbiased Estimator (BLUE) and modifying the initial soil moisture states, showed an improvement of the streamflow analysis with low soil moisture increments. The final states of this suite were used to initialize the ensemble streamflow forecasts of Météo-France, which are based on the SIM model and use the European Centre for Medium-range Weather Forecasts (ECMWF) 10-day Ensemble Prediction System (EPS). Two different configurations of the assimilation system were used in this study: the first with the classical SIM model and the second using improved soil physics in ISBA. The effects of the assimilation system on the ensemble streamflow forecasts were assessed for these two configurations, and a comparison was made with the original (i.e. without data assimilation and without the improved physics) ensemble streamflow forecasts. It is shown that the assimilation system improved most of the statistical scores usually computed for the validation of ensemble predictions (RMSE, Brier Skill Score and its decomposition, Ranked Probability Skill Score, False Alarm Rate, etc

  14. Effectiveness of the streamflow-gaging network in Kentucky in providing regional streamflow information

    USGS Publications Warehouse

    Ruhl, K.J.

    1993-01-01

    This report describes the results of an analysis of the effectiveness of the strearnflow-gaging network in Kentucky in providing regional streamflow information. The data available for analysis included streamflow-gaging stations in Kentucky and selected stations in adjoining States. One phase of the analysis determined the increased effectiveness of the network if hypothetical new stations were added to it. The analysis was based on the principles of generalized least squares regression. The results indicated that new stations having small drainage areas (less than 100 square miles) produced the greatest reduction in average sampling-error variance from current conditions in the mean-flow analysis. Only stations with drainage areas ranging from 200 to 450 square miles produced a significant effect on the low-flow analysis. Data from new stations having small drainage areas (less than 100 square miles) and fairly steep slopes (25 feet per mile) would make the greatest improvement in peak-flow information.

  15. August median streamflow on ungaged streams in Eastern Coastal Maine

    USGS Publications Warehouse

    Lombard, Pamela J.

    2004-01-01

    Methods for estimating August median streamflow were developed for ungaged, unregulated streams in eastern coastal Maine. The methods apply to streams with drainage areas ranging in size from 0.04 to 73.2 square miles and fraction of basin underlain by a sand and gravel aquifer ranging from 0 to 71 percent. The equations were developed with data from three long-term (greater than or equal to 10 years of record) continuous-record streamflow-gaging stations, 23 partial-record streamflow- gaging stations, and 5 short-term (less than 10 years of record) continuous-record streamflow-gaging stations. A mathematical technique for estimating a standard low-flow statistic, August median streamflow, at partial-record streamflow-gaging stations and short-term continuous-record streamflow-gaging stations was applied by relating base-flow measurements at these stations to concurrent daily streamflows at nearby long-term continuous-record streamflow-gaging stations (index stations). Generalized least-squares regression analysis (GLS) was used to relate estimates of August median streamflow at streamflow-gaging stations to basin characteristics at these same stations to develop equations that can be applied to estimate August median streamflow on ungaged streams. GLS accounts for different periods of record at the gaging stations and the cross correlation of concurrent streamflows among gaging stations. Thirty-one stations were used for the final regression equations. Two basin characteristics?drainage area and fraction of basin underlain by a sand and gravel aquifer?are used in the calculated regression equation to estimate August median streamflow for ungaged streams. The equation has an average standard error of prediction from -27 to 38 percent. A one-variable equation uses only drainage area to estimate August median streamflow when less accuracy is acceptable. This equation has an average standard error of prediction from -30 to 43 percent. Model error is larger than

  16. Climatic fluctuations and the timing of west coast streamflow

    SciTech Connect

    Aguado, E. ); Cayan, D.; Riddle, L. ); Roos, M. )

    1992-12-01

    Since about 1950 there has been a trend in the California Sierra Nevada toward a decreasing portion of the total annual streamflow occurring during April through July, while the streamflow during autumn and winter has increased. This trend not only has important ramifications with regard to water mangement, it also brings up the question of whether this represents a shift toward earlier release of the snowpack resulting from greenhouse warming. Therefore, the observed record has been examined in terms of relative influences of temperature and precipitation anomalies on the timing of streamflow in this region. To carry out this study, the fraction of annual streamflow (called the fractional streamflow) occurring in November-January (NDJ), February-April (FMA), and May-July (MJJ) at low, medium and high elevation basins in California and Oregon was examined. Linear regression models were used to relate precipitation and temperature to the fractional streamflow at the three elevations for each season. Composites of monthly temperature and precipitation were employed to further examine the fractional streamflow in its high and low tercile extremes. Long time series of climatic and hydrologic data were also looked at to infer the causes in the trend toward earlier runoff. 14 refs., 13 figs., 4 tabs.

  17. New method for calculating a mathematical expression for streamflow recession

    USGS Publications Warehouse

    Rutledge, Albert T.

    1991-01-01

    An empirical method has been devised to calculate the master recession curve, which is a mathematical expression for streamflow recession during times of negligible direct runoff. The method is based on the assumption that the storage-delay factor, which is the time per log cycle of streamflow recession, varies linearly with the logarithm of streamflow. The resulting master recession curve can be nonlinear. The method can be executed by a computer program that reads a data file of daily mean streamflow, then allows the user to select several near-linear segments of streamflow recession. The storage-delay factor for each segment is one of the coefficients of the equation that results from linear least-squares regression. Using results for each recession segment, a mathematical expression of the storage-delay factor as a function of the log of streamflow is determined by linear least-squares regression. The master recession curve, which is a second-order polynomial expression for time as a function of log of streamflow, is then derived using the coefficients of this function.

  18. Estimating ice-affected streamflow by extended Kalman filtering

    USGS Publications Warehouse

    Holtschlag, D.J.; Grewal, M.S.

    1998-01-01

    An extended Kalman filter was developed to automate the real-time estimation of ice-affected streamflow on the basis of routine measurements of stream stage and air temperature and on the relation between stage and streamflow during open-water (ice-free) conditions. The filter accommodates three dynamic modes of ice effects: sudden formation/ablation, stable ice conditions, and eventual elimination. The utility of the filter was evaluated by applying it to historical data from two long-term streamflow-gauging stations, St. John River at Dickey, Maine and Platte River at North Bend, Nebr. Results indicate that the filter was stable and that parameters converged for both stations, producing streamflow estimates that are highly correlated with published values. For the Maine station, logarithms of estimated streamflows are within 8% of the logarithms of published values 87.2% of the time during periods of ice effects and within 15% 96.6% of the time. Similarly, for the Nebraska station, logarithms of estimated streamflows are within 8% of the logarithms of published values 90.7% of the time and within 15% 97.7% of the time. In addition, the correlation between temporal updates and published streamflows on days of direct measurements at the Maine station was 0.777 and 0.998 for ice-affected and open-water periods, respectively; for the Nebraska station, corresponding correlations were 0.864 and 0.997.

  19. Climate and streamflow of Puerto Rico

    USGS Publications Warehouse

    Giusti, E.V.; Lopez, M.A.

    1967-01-01

    THE PRESENTLY AVAILABLE DATA ON STREAMFLOW, RUNOFF RAINFALL, AND TEMPERATURE OFPUERTO RICO ARE EVALUATED, ALTHOUGH THE PERIOD OF RECORD IS VERY SHORT, WITH A VIEW TO CONTRIBUTING TO THE KNOWLEDGE OF HYDROLOGY OF TROPICAL ISLANDS. THE AVERAGE ANNUAL STREAMFLOW IN PUERTO RICO IS 56% OF THE ANNUAL RAINFALL, OR 15% MORE THAN IN THE EASTERN PIEDMONT OF THE U S WHERE IT IS 30%. CLIMATE IS ASSUMED TO BE RESPONSIBLE FOR THIS DIFFERENCE AS WELL AS FOR THE DIFFERENCES OF THE FLOWS OF PUERTORICAN STREAMS WHICH VARY FROM 15 TO 85% OF THE ANNUAL RAINFALL. VARIATIONS IN THE CLIMATE OF PUERTO RICOARE SHOWN BY THORNTHWAITE'S CLIMATIC INDEX ON A MAP OF THE ISLAND, AND THE VARIATIONS OF THESTREAMFLOW TO RAINFALL RATIOS OF PUERTO RICAN STREAMS ARE SHOWN TO BE RELATED TO THORNTHWAITE'S CLIMATIC INDEX. (KNAPP-USGS) 

  20. Estimating monthly streamflow values by cokriging

    USGS Publications Warehouse

    Solow, A.R.; Gorelick, S.M.

    1986-01-01

    Cokriging is applied to estimation of missing monthly streamflow values in three records from gaging stations in west central Virginia. Missing values are estimated from optimal consideration of the pattern of auto- and cross-correlation among standardized residual log-flow records. Investigation of the sensitivity of estimation to data configuration showed that when observations are available within two months of a missing value, estimation is improved by accounting for correlation. Concurrent and lag-one observations tend to screen the influence of other available observations. Three models of covariance structure in residual log-flow records are compared using cross-validation. Models differ in how much monthly variation they allow in covariance. Precision of estimation, reflected in mean squared error (MSE), proved to be insensitive to this choice. Cross-validation is suggested as a tool for choosing an inverse transformation when an initial nonlinear transformation is applied to flow values. ?? 1986 Plenum Publishing Corporation.

  1. Forecasting of Annual Streamflow Using Data-Driven Modeling Approach

    NASA Astrophysics Data System (ADS)

    Kalra, A.; Miller, W. P.; Ahmad, S.; Lamb, K. W.

    2010-12-01

    In a water-stressed region, such as the western United States, it is essential to have long lead-time streamflow forecast for reservoir operation and water resources management. In this study, we develop and examine the accuracy of a data driven model incorporating large-scale climate information for extending streamflow forecast lead-time. A data driven model i.e. Support Vector Machine (SVM) based on the statistical learning theory is used to predict annual streamflow volume 1-year in advance. The SVM model is a learning system that uses a hypothesis space of linear functions in a Kernel induced higher dimensional feature space, and is trained with a learning algorithm from the optimization theory. Annual oceanic-atmospheric indices, comprising of Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), El Niño-Southern Oscillations (ENSO), and a new Sea Surface Temperature (SST) data set of “Hondo” region for a period of 1906-2006 are used to generate annual streamflow volumes for multiple sites in Gunnison River Basin (GRB) and San Juan River Basin (SJRB) located in the Upper Colorado River Basin (UCRB). Based on Correlation Coefficient, Root Means Square Error, and Mean Absolute Error the model shows satisfactory results, and the predictions are in good agreement with measured streamflow volumes. Previous research has identified NAO and ENSO as main drivers for extending streamflow forecast lead-time in the UCRB. Contrary to this, the current research shows a stronger signal between the “Hondo” region SST and GRB and SJRB streamflow for 1-year lead-time. Streamflow predictions from the SVM model are found to be better when compared with the predictions obtained from feed-forward back propagation Artificial Neural Network model and Multiple Linear Regression model. The streamflow forecast provide valuable and useful information for optimal management and planning of water resources in the basins.

  2. A Streamflow Statistics (StreamStats) Web Application for Ohio

    USGS Publications Warehouse

    Koltun, G.F.; Kula, Stephanie P.; Puskas, Barry M.

    2006-01-01

    A StreamStats Web application was developed for Ohio that implements equations for estimating a variety of streamflow statistics including the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year peak streamflows, mean annual streamflow, mean monthly streamflows, harmonic mean streamflow, and 25th-, 50th-, and 75th-percentile streamflows. StreamStats is a Web-based geographic information system application designed to facilitate the estimation of streamflow statistics at ungaged locations on streams. StreamStats can also serve precomputed streamflow statistics determined from streamflow-gaging station data. The basic structure, use, and limitations of StreamStats are described in this report. To facilitate the level of automation required for Ohio's StreamStats application, the technique used by Koltun (2003)1 for computing main-channel slope was replaced with a new computationally robust technique. The new channel-slope characteristic, referred to as SL10-85, differed from the National Hydrography Data based channel slope values (SL) reported by Koltun (2003)1 by an average of -28.3 percent, with the median change being -13.2 percent. In spite of the differences, the two slope measures are strongly correlated. The change in channel slope values resulting from the change in computational method necessitated revision of the full-model equations for flood-peak discharges originally presented by Koltun (2003)1. Average standard errors of prediction for the revised full-model equations presented in this report increased by a small amount over those reported by Koltun (2003)1, with increases ranging from 0.7 to 0.9 percent. Mean percentage changes in the revised regression and weighted flood-frequency estimates relative to regression and weighted estimates reported by Koltun (2003)1 were small, ranging from -0.72 to -0.25 percent and -0.22 to 0.07 percent, respectively.

  3. Shift of extreme spring streamflow on the Belorussian rivers and its association with changes of cyclonic activity over Eastern Europe

    NASA Astrophysics Data System (ADS)

    Partasenok, Irina; Chekan, Gregory

    2014-05-01

    The intra-annual distribution of precipitation is the most variable component of the water resources of Belarus. This distribution is controlled by extratropical cyclones from the Atlantic Ocean and Mediterranean that bring most of precipitation to the nation. That's why the aim of our study was to quantify major characteristics of these cyclones and to estimate effects of their passing through the Belorussian territory on regional water budget including floods and low water conditions. We documented the long-term fluctuations of streamflow and occurrence of extreme phenomena on the rivers of Belarus during the post-World War II period. It was established that annual water budget of the nation vary from year to year without systematic tendencies. At the same time, analysis of intra-annual distribution of streamflow reveals significant changes since the 1970s: increase of winter and decrease of spring runoff. As a result, the frequency of extreme spring floods has decreased. These changes in water regime are associated with climatic anomalies caused by large-scale alterations in atmospheric circulation, specifically in trajectories of cyclones. As a manifestation of these circulation changes, we observe increase of the surface air temperatures, more frequent cold season thaws, redistribution of seasonal precipitation totals, and decrease of the fraction of frozen precipitation in the shoulder seasons. Analysis of cyclonic activity over Belarus during the past 60 years in the cold season (December through February) shows the largest number of cyclones in 1950-1970. During this period, the largest number of spring floods caused by snowmelt on the rivers of Belarus was reported. Since 1970, we observe a decrease in the total number of cyclones but also an increasing strength (deepening) of the remaining cyclones in the cold season. That has led to some precipitation increase. During the last four decades, more frequent zonal air movement in the atmosphere and

  4. Indicator bacteria and associated water quality constituents in stormwater and snowmelt from four urban catchments

    NASA Astrophysics Data System (ADS)

    Galfi, H.; Österlund, H.; Marsalek, J.; Viklander, M.

    2016-08-01

    Four indicator bacteria were measured in association with physico-chemical constituents and selected inorganics during rainfall, baseflow and snowmelt periods in storm sewers of four urban catchments in a northern Swedish city. The variation patterns of coliforms, Escherichia coli, enterococci and Clostridium perfringens concentrations were assessed in manually collected grab samples together with those of phosphorus, nitrogen, solids, and readings of pH, turbidity, water conductivity, temperature and flow rates to examine whether these constituents could serve as potential indicators of bacteria sources. A similar analysis was applied to variation patterns of eight selected inorganics typical for baseflow and stormwater runoff to test the feasibility of using these inorganics to distinguish between natural and anthropogenic sources of inflow into storm sewers. The monitored catchments varied in size, the degree of development, and land use. Catchment and season (i.e., rainy or snowmelt periods) specific variations were investigated for sets of individual stormwater samples by the principal component analysis (PCA) to identify the constituents with variation patterns similar to those of indicator bacteria, and to exclude the constituents with less similarity. In the reduced data set, the similarities were quantified by the clustering correlation analysis. Finally, the positive/negative relationships found between indicator bacteria and the identified associated constituent groups were described by multilinear regressions. In the order of decreasing concentrations, coliforms, E. coli and enterococci were found in the highest mean concentrations during both rainfall and snowmelt generated runoff. Compared to dry weather baseflow, concentrations of these three indicators in stormwater were 10 (snowmelt runoff) to 102 (rain runoff) times higher. C. perfringens mean concentrations were practically constant regardless of the season and catchment. The type and number of

  5. Modeling the snow surface temperature with a one-layer energy balance snowmelt model

    NASA Astrophysics Data System (ADS)

    You, J.; Tarboton, D. G.; Luce, C. H.

    2014-12-01

    Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort to keep snowmelt modeling simple and parsimonious, the Utah Energy Balance (UEB) snowmelt model used only one layer but allowed the snow surface temperature to be different from the snow average temperature by using an equilibrium gradient parameterization based on the surface energy balance. Although this procedure was considered an improvement over the ordinary single layer snowmelt models, it still resulted in discrepancies between modeled and measured snowpack energy contents. In this paper we evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach when they are integrated as part of a complete energy and mass balance snowmelt model. The force-restore and modified force-restore approaches have not been incorporated into the UEB in early versions, even though Luce and Tartoton have done work in calculating the energy components using these approaches. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We introduce a method to adjust effective conductivity to account for the presence of ground near to a shallow snow surface. These parameterizations were tested against data from the Central Sierra Snow Laboratory, CA, Utah State University experimental farm, UT, and subnivean snow laboratory at Niwot Ridge, CO

  6. The National Streamflow Statistics Program: A Computer Program for Estimating Streamflow Statistics for Ungaged Sites

    USGS Publications Warehouse

    Ries(compiler), Kernell G., III; With sections by Atkins, J. B.; Hummel, P.R.; Gray, Matthew J.; Dusenbury, R.; Jennings, M.E.; Kirby, W.H.; Riggs, H.C.; Sauer, V.B.; Thomas, W.O., Jr.

    2007-01-01

    The National Streamflow Statistics (NSS) Program is a computer program that should be useful to engineers, hydrologists, and others for planning, management, and design applications. NSS compiles all current U.S. Geological Survey (USGS) regional regression equations for estimating streamflow statistics at ungaged sites in an easy-to-use interface that operates on computers with Microsoft Windows operating systems. NSS expands on the functionality of the USGS National Flood Frequency Program, and replaces it. The regression equations included in NSS are used to transfer streamflow statistics from gaged to ungaged sites through the use of watershed and climatic characteristics as explanatory or predictor variables. Generally, the equations were developed on a statewide or metropolitan-area basis as part of cooperative study programs. Equations are available for estimating rural and urban flood-frequency statistics, such as the 1 00-year flood, for every state, for Puerto Rico, and for the island of Tutuila, American Samoa. Equations are available for estimating other statistics, such as the mean annual flow, monthly mean flows, flow-duration percentiles, and low-flow frequencies (such as the 7-day, 0-year low flow) for less than half of the states. All equations available for estimating streamflow statistics other than flood-frequency statistics assume rural (non-regulated, non-urbanized) conditions. The NSS output provides indicators of the accuracy of the estimated streamflow statistics. The indicators may include any combination of the standard error of estimate, the standard error of prediction, the equivalent years of record, or 90 percent prediction intervals, depending on what was provided by the authors of the equations. The program includes several other features that can be used only for flood-frequency estimation. These include the ability to generate flood-frequency plots, and plots of typical flood hydrographs for selected recurrence intervals

  7. A past discharge assimilation system for ensemble streamflow forecasts over France - Part 2: Impact on the ensemble streamflow forecasts

    NASA Astrophysics Data System (ADS)

    Thirel, G.; Martin, E.; Mahfouf, J.-F.; Massart, S.; Ricci, S.; Regimbeau, F.; Habets, F.

    2010-04-01

    The use of ensemble streamflow forecasts is developing in the international flood forecasting services. Such systems can provide more accurate forecasts and useful information about the uncertainty of the forecasts, thus improving the assessment of risks. Nevertheless, these systems, like all hydrological forecasts, suffer from errors on initialization or on meteorological data, which lead to hydrological prediction errors. This article, which is the second part of a 2-part article, concerns the impacts of initial states, improved by a streamflow assimilation system, on an ensemble streamflow prediction system over France. An assimilation system was implemented to improve the streamflow analysis of the SAFRAN-ISBA-MODCOU (SIM) hydro-meteorological suite, which initializes the ensemble streamflow forecasts at Météo-France. This assimilation system, using the Best Linear Unbiased Estimator (BLUE) and modifying the initial soil moisture states, showed an improvement of the streamflow analysis with low soil moisture increments. The final states of this suite were used to initialize the ensemble streamflow forecasts of Météo-France, which are based on the SIM model and use the European Centre for Medium-range Weather Forecasts (ECMWF) 10-day Ensemble Prediction System (EPS). Two different configurations of the assimilation system were used in this study: the first with the classical SIM model and the second using improved soil physics in ISBA. The effects of the assimilation system on the ensemble streamflow forecasts were assessed for these two configurations, and a comparison was made with the original (i.e. without data assimilation and without the improved physics) ensemble streamflow forecasts. It is shown that the assimilation system improved most of the statistical scores usually computed for the validation of ensemble predictions (RMSE, Brier Skill Score and its decomposition, Ranked Probability Skill Score, False Alarm Rate, etc.), especially for the first

  8. Validated Metrics of Quick Flow Improve Assessments of Streamflow Generation Processes at the Long-Term Sleepers River Research Site

    NASA Astrophysics Data System (ADS)

    Sebestyen, S. D.; Shanley, J. B.

    2015-12-01

    There are multiple approaches to quantify quick flow components of streamflow. Physical hydrograph separations of quick flow using recession analysis (RA) are objective, reproducible, and easily calculated for long-duration streamflow records (years to decades). However, this approach has rarely been validated to have a physical basis for interpretation. In contrast, isotopic hydrograph separation (IHS) and end member mixing analysis using multiple solutes (EMMA) have been used to identify flow components and flowpath routing through catchment soils. Nonetheless, these two approaches are limited by data from limited and isolated periods (hours to weeks) during which more-intensive grab samples were analyzed. These limitations oftentimes make IHS and EMMA difficult to generalize beyond brief windows of time. At the Sleepers River Research Watershed (SRRW) in northern Vermont, USA, we have data from multiple snowmelt events over a two decade period and from multiple nested catchments to assess relationships among RA, IHS, and EMMA. Quick flow separations were highly correlated among the three techniques, which shows links among metrics of quick flow, water sources, and flow path routing in a small (41 ha), forested catchment (W-9) The similarity in responses validates a physical interpretation for a particular RA approach (the Ekhardt recursive RA filter). This validation provides a new tool to estimate new water inputs and flowpath routing for more and longer periods when chemical or isotopic tracers may not have been measured. At three other SRRW catchments, we found similar strong correlations among the three techniques. Consistent responses across four catchments provide evidence to support other research at the SRRW that shows that runoff generation mechanisms are similar despite differences in catchment sizes and land covers.

  9. Tracing sources of nitrate in snowmelt runoff using a high-resolution isotopic technique

    NASA Astrophysics Data System (ADS)

    Ohte, N.; Sebestyen, S. D.; Shanley, J. B.; Doctor, D. H.; Kendall, C.; Wankel, S. D.; Boyer, E. W.

    2004-11-01

    The denitrifier method to determine the dual isotopic composition (δ15N and δ18O) of nitrate is well suited for studies of nitrogen contributions to streams during runoff events. This method requires only 70 nmol of NO3- and enables high throughput of samples. We studied nitrate sources to a headwater stream during snowmelt by generating a high-temporal resolution dataset at the Sleepers River Research Watershed in Vermont, USA. In the earliest phase of runoff, stream NO3- concentrations were highest and stream discharge, NO3- concentrations, and δ18O of NO3- generally tracked one another during diurnal melting. The isotopic composition of stream NO3- varied in-between atmospheric and groundwater NO3- end members indicating a direct contribution of atmospherically-derived NO3- from the snow pack to the stream. During the middle to late phases of snowmelt, the source shifted toward soil NO3- entering the stream via shallow subsurface flow paths.

  10. Evaluation of Streamflow Requirements for Habitat Protection by Comparison to Streamflow Characteristics at Index Streamflow-Gaging Stations in Southern New England

    USGS Publications Warehouse

    Armstrong, David S.; Parker, Gene W.; Richards, Todd A.

    2003-01-01

    Streamflow characteristics and methods for determining streamflow requirements for habitat protection were investigated at 23 active index streamflow-gaging stations in southern New England. Fish communities sampled near index streamflow-gaging stations in Massachusetts have a high percentage of fish that require flowing-water habitats for some or all of their life cycle. The relatively unaltered flow condition at these sites was assumed to be one factor that has contributed to this condition. Monthly flow durations and low flow statistics were determined for the index streamflow-gaging stations for a 25-year period from 1976 to 2000. Annual hydrographs were prepared for each index station from median streamflows at the 50-percent monthly flow duration, normalized by drainage area. A median monthly flow of 1 ft3/s/mi2 was used to split hydrographs into a high-flow period (November?May), and a low-flow period (June?October). The hydrographs were used to classify index stations into groups with similar median monthly flow durations. Index stations were divided into four regional groups, roughly paralleling the coast, to characterize streamflows for November to May; and into two groups, on the basis of base-flow index and percentage of sand and gravel in the contributing area, for June to October. For the June to October period, for index stations with a high base-flow index and contributing areas greater than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.57, 0.49, and 0.46 ft3/s/mi2 for July, August, and September, respectively. For index stations with a low base-flow index and contributing areas less than 20 percent sand and gravel, median streamflows at the 50-percent monthly flow duration, normalized by drainage area, were 0.34, 0.28, and 0.27 ft3/s/mi2 for July, August, and September, respectively. Streamflow variability between wet and dry years can be characterized by use of the

  11. Streamflow sensitivity to water storage changes across Europe

    NASA Astrophysics Data System (ADS)

    Berghuijs, Wouter R.; Hartmann, Andreas; Woods, Ross A.

    2016-03-01

    Terrestrial water storage is the primary source of river flow. We introduce storage sensitivity of streamflow (ɛS), which for a given flow rate indicates the relative change in streamflow per change in catchment water storage. ɛS can be directly derived from streamflow observations. Analysis of 725 catchments in Europe reveals that ɛS is high in, e.g., parts of Spain, England, Germany, and Denmark, whereas flow regimes in parts of the Alps are more resilient (that is, less sensitive) to storage changes. A regional comparison of ɛS with observations indicates that ɛS is significantly correlated with variability of low (R2 = 0.41), median (R2 = 0.27), and high flow conditions (R2 = 0.35). Streamflow sensitivity provides new guidance for a changing hydrosphere where groundwater abstraction and climatic changes are altering water storage and flow regimes.

  12. EVALUATING THE EFFECT OF UPSTREAM WATERSHED ACTIVITIES TO DOWNSTREAM STREAMFLOW

    EPA Science Inventory

    Linking the impacts of upstream activities such as urban development to changes in downstream streamflow is critical to achieving a balance between economic development and environmental protection as a basis for sustainable watershed development. This paper presents a modeling a...

  13. Trends in Rainfall, Streamflow, and Interannual Variability in Palau

    NASA Astrophysics Data System (ADS)

    Gupta, A.

    2008-05-01

    Anecdotal evidence from Palau suggests that streamflow may be declining with time. This research examines trends in rainfall and streamflow and attempts to identify causes of variability. Rainfall for the period of 1953-2002 exhibited a significant declining trend. Rainfall intensity appears to be increasing and interannual variability also shows an increasing trend. Streamflow also exhibited significant decreasing trends for the period of the early 1970s to early 1990s. Precipitation in Palau is only moderately correlated with the PDO, ENSO, and SO indices. Declining rainfall and streamflow conditions have important policy implications for the developing island nation, which is currently exhibiting rapid population growth. A lack of strong correlation with regional climate indices is also problematic when making flood and drought predictions.

  14. Scale effects on information content and complexity of streamflows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding temporal and spatial variations of streamflows is important for flood forecasting, water resources management, and revealing interactions between hydrologic processes (e.g., precipitation, evapotranspiration, and soil water and groundwater flows.) The information theory has been used i...

  15. Streamflow response to increasing precipitation extremes altered by forest management

    NASA Astrophysics Data System (ADS)

    Kelly, Charlene N.; McGuire, Kevin J.; Miniat, Chelcy Ford; Vose, James M.

    2016-04-01

    Increases in extreme precipitation events of floods and droughts are expected to occur worldwide. The increase in extreme events will result in changes in streamflow that are expected to affect water availability for human consumption and aquatic ecosystem function. We present an analysis that may greatly improve current streamflow models by quantifying the impact of the interaction between forest management and precipitation. We use daily long-term data from paired watersheds that have undergone forest harvest or species conversion. We find that interactive effects of climate change, represented by changes in observed precipitation trends, and forest management regime, significantly alter expected streamflow most often during extreme events, ranging from a decrease of 59% to an increase of 40% in streamflow, depending upon management. Our results suggest that vegetation might be managed to compensate for hydrologic responses due to climate change to help mitigate effects of extreme changes in precipitation.

  16. Use of areal snow cover measurements from ERTS-1 imagery in snowmelt-runoff relationships in Arizona

    NASA Technical Reports Server (NTRS)

    Aul, J. S.; Ffolliott, P. F.

    1975-01-01

    Methods of interpreting ERTS-1 imagery to measure areal snow cover were analyzed. Relationship of areal snow cover and runoff were among the objectives in this study of ERTS-1 imagery use for forecasting snowmelt-runoff relationships.

  17. Dissolved organic matter transport reflects hillslope to stream connectivity during snowmelt in a montane catchment

    NASA Astrophysics Data System (ADS)

    Burns, Margaret A.; Barnard, Holly R.; Gabor, Rachel S.; McKnight, Diane M.; Brooks, Paul D.

    2016-06-01

    Dissolved organic matter (DOM) transport is a key biogeochemical linkage across the terrestrial-aquatic interface in headwater catchments, and quantifying the biological and hydrological controls on DOM composition provides insight into DOM cycling at the catchment scale. We evaluated the mobility of DOM components during snowmelt in a montane, semiarid catchment. DOM composition was evaluated on a near-daily basis within the soil and the stream during snowmelt, and was compared to groundwater samples using a site-specific parallel factor analysis (PARAFAC) model derived from soil extracts. The fluorescent component loadings in the interstitial soil water and in the groundwater were significantly different and did not temporally change during snowmelt. In the stream, a transition occurred during snowmelt from fluorescent DOM with higher contributions of amino acid-like components indicative of groundwater to higher humic-like contributions indicative of soil water. Furthermore, we identified a humic-like fluorescent component in the soil water and the stream that is typically only observed in extracted water soluble organic matter from soil which may suggest hillslope to stream connectivity over very short time scales. Qualitative interpretations of changes in stream fluorescent DOM were supported by two end-member mixing analyses of conservative tracers. After normalizing fluorescent DOM loadings for dissolved organic carbon (DOC) concentration, we found that the peak in DOC concentration in the stream was driven by the nonfluorescent fraction of DOM. This study demonstrated how PARAFAC analysis can be used to refine our conceptual models of runoff generation sources, as well as provide a more detailed understanding of stream chemistry dynamics.

  18. Spatial controls on groundwater response dynamics in a snowmelt-dominated montane catchment

    NASA Astrophysics Data System (ADS)

    Smith, R. S.; Moore, R. D.; Weiler, M.; Jost, G.

    2014-05-01

    The role of spatial variability in water inputs on runoff dynamics has generally not received as much research attention as topography and soils; however, the influence of topography and forest cover on snow surface energy exchanges can result in asynchronous snowmelt throughout a catchment, complicating the space-time patterns of runoff generation. This study investigates temporal variation in the relative importance of spatial controls on the occurrence, duration, and timing of shallow groundwater response, utilizing a highly distributed monitoring network in a snowmelt-dominated montane catchment in western Canada. The study findings indicate that deep-soil hydraulic conductivity is a first-order control on the spatial distribution of sites that generate shallow groundwater response versus sites that experience only deep percolation. Upslope contributing area and slope gradient are first-order controls on the duration of groundwater response during peak-flow, recession-flow, and low-flow periods. Shallow runoff response areas expand and contract throughout these periods and follow the general spatial patterns of topographic convergence. However, spatial controls on the timing, intensity, and quantity of snowmelt and controls on vertical versus lateral flux partitioning in the soil overwhelm the influence of topographic convergence on runoff patterns during early spring freshet periods. The study findings suggest that various topographic indices and topography-based rainfall runoff models would not likely be good predictors of runoff patterns in snowmelt-dominated montane catchments during early phases of the spring freshet, but would increase in importance as the freshet and post-freshet periods proceed.

  19. A proposed streamflow-data program for Puerto Rico

    USGS Publications Warehouse

    Lopez, Miguel A.; Fields, Fred K.

    1970-01-01

    The streamflow-data program of the U.S. Geological Survey (USGS) in Puerto Rico has been one of the principal parts of an overall appraisal of the water resources of the Island since the initiation of a cooperative agreement with agencies of the Commonwealth Government in 1957. The streamflow-station network has increased in direct response to demand for data to support planning for the rapidly accelerated industrial and population growth that has occurred since.

  20. Testing and modelling autoregressive conditional heteroskedasticity of streamflow processes

    NASA Astrophysics Data System (ADS)

    Wang, W.; van Gelder, P. H. A. J. M.; Vrijling, J. K.; Ma, J.

    2005-01-01

    Conventional streamflow models operate under the assumption of constant variance or season-dependent variances (e.g. ARMA (AutoRegressive Moving Average) models for deseasonalized streamflow series and PARMA (Periodic AutoRegressive Moving Average) models for seasonal streamflow series). However, with McLeod-Li test and Engle's Lagrange Multiplier test, clear evidences are found for the existence of autoregressive conditional heteroskedasticity (i.e. the ARCH (AutoRegressive Conditional Heteroskedasticity) effect), a nonlinear phenomenon of the variance behaviour, in the residual series from linear models fitted to daily and monthly streamflow processes of the upper Yellow River, China. It is shown that the major cause of the ARCH effect is the seasonal variation in variance of the residual series. However, while the seasonal variation in variance can fully explain the ARCH effect for monthly streamflow, it is only a partial explanation for daily flow. It is also shown that while the periodic autoregressive moving average model is adequate in modelling monthly flows, no model is adequate in modelling daily streamflow processes because none of the conventional time series models takes the seasonal variation in variance, as well as the ARCH effect in the residuals, into account. Therefore, an ARMA-GARCH (Generalized AutoRegressive Conditional Heteroskedasticity) error model is proposed to capture the ARCH effect present in daily streamflow series, as well as to preserve seasonal variation in variance in the residuals. The ARMA-GARCH error model combines an ARMA model for modelling the mean behaviour and a GARCH model for modelling the variance behaviour of the residuals from the ARMA model. Since the GARCH model is not followed widely in statistical hydrology, the work can be a useful addition in terms of statistical modelling of daily streamflow processes for the hydrological community.

  1. Selected streamflow data for the Delaware River basin

    USGS Publications Warehouse

    Schopp, Robert D.; Gillespie, Brian D.

    1979-01-01

    Selected streamflow data for the Delaware River basin include runoff-precipitation relationships for 28 selected subbasins for the period 1941-70; low-flow frequency curves for four mainstem Delaware River sites; monthly comparative duration curves and twenty year hydrographs at Montague and Trenton, New Jersey; and flow duration tables based on observed daily streamflow for gaging stations near 21 proposed dam sites. (Woodard-USGS)

  2. Historical Climate and Streamflow Trends in Santa Ana River Basin

    NASA Astrophysics Data System (ADS)

    Mejia, D.; Sultana, R.; Tang, V.

    2015-12-01

    Santa Ana River watershed, located in Southern California, is the home of more than 5 million people. Population is projected to double within the next 50 years in the 2,650 square miles watershed. With prolonged drought conditions, and projected climate change, a strong concern exists about sustainable water supply of the area. In this study, historic climate and streamflow trend from water year 1965 to 2014 is analyzed using the nonparametric Mann-Kendall test. Climate trends are studied using annual rainfall, and annual average maximum and minimum temperature at 5 and 4 weather stations, respectively. Three of the precipitation stations show precipitation is decreasing in the watershed while minimum and maximum temperature has an increasing trend at three stations (p < 0.05). To assess whether streamflow and stream-channel characteristics are tended to increase or decrease monotonically with time, four variables - (1) annual maximum peak, (2) annual mean, (3) low to moderate and (4) moderate to high maximum peak streamflow were tested at 20 stream gauge sites. Only at 5 stream gage stations, significant streamflow trend is observed. At two stream gages, annual peak and annual average streamflow is increasing and at two stations, annual average streamflow has a decreasing trend. Low to moderate peak streamflow is increasing at two gage locations but there is no monotonic trend in moderate to high flows. As precipitation is decreasing in some part of the watershed, the effect of increasing urbanization in the area can be attributed for the localized increase in mean and peak streamflow. The trend analysis in weather and stream gage data will be presented in detail.

  3. Implication of mountain shading and topographic scaling on energy for snowmelt

    NASA Astrophysics Data System (ADS)

    Marsh, C.; Pomeroy, J. W.; Spiteri, R.

    2011-12-01

    In many parts of the world, snowmelt energetics are dominated by incoming solar radiation. This is the case in the Canadian Rockies, where sunny winters result in high insolation. Solar irradiance on the snow surface is affected by the atmosphere, the slope and aspect of the immediate topography, and shading from surrounding terrain. Errors in estimating solar irradiation are cumulative over a season and can lead to large errors in snowmelt predictions. Adaptive triangular meshes, a type of unstructured triangular mesh that can adapt to fine-scale processes during model runtime, are more efficient in their use of DEM data than fixed grids when producing solar irradiance maps. An experimental design to calculate the effect of changes in DEM resolution on adaptive mesh irradiation calculations and implication for snowmelt is presented. As part of this experiment, the accuracy of these techniques is compared to measurements of mountain shadows and solar irradiance collected in Marmot Creek Research Basin, Alberta. Time-lapse digital cameras and networks of radiometers provide datasets for diagnosis of model accuracy. Further improvements in computational efficiency are achieved by taking advantage of parallel processing using graphical processing units (GPUs) is also discussed.

  4. The response of aboveground plant productivity to earlier snowmelt and summer warming in an Arctic ecosystem

    NASA Astrophysics Data System (ADS)

    Livensperger, C.; Steltzer, H.; Darrouzet-Nardi, A.; Sullivan, P.; Wallenstein, M. D.; Weintraub, M. N.

    2012-12-01

    Plant communities in the Arctic are undergoing changes in structure and function due to shifts in seasonality from changing winters and summer warming. These changes will impact biogeochemical cycling, surface energy balance, and functioning of vertebrate and invertebrate communities. To examine seasonal controls on aboveground net primary production (ANPP) in a moist acidic tundra ecosystem in northern Alaska, we shifted the growing season by accelerating snowmelt (using radiation absorbing shadecloth) and warming air and soil temperature (using 1 m2 open-top chambers), individually and in combination. After three years, we measured ANPP by harvesting up to 16 individual ramets, tillers and rhizomes for each of 7 plant species, including two deciduous shrubs, two graminoids, two evergreen shrubs and one forb during peak season. Our results show that ANPP per stem summed across the 7 species increased when snow melt occurred earlier. However, standing biomass, excluding current year growth, was also greater. The ratio of ANPP/standing biomass decreased in all treatments compared to the control. ANPP per unit standing biomass summed for the four shrub species decreases due to summer warming alone or in combination with early snowmelt; however early snowmelt alone did not lead to lower ANPP for the shrubs. ANPP per tiller or rhizome summed for the three herbaceous species increased in response to summer warming. Understanding the differential response of plants to changing seasonality will inform predictions of future Arctic plant community structure and function.

  5. The fate of mercury species in a sub-arctic snowpack during snowmelt

    NASA Astrophysics Data System (ADS)

    Dommergue, Aurélien; Ferrari, Christophe P.; Gauchard, Pierre-Alexis; Boutron, Claude F.; Poissant, Laurier; Pilote, Martin; Jitaru, Petru; Adams, Freddy C.

    2003-06-01

    An extensive mercury study was conducted in April 2002 prior to and during the annual melting of a snowpack in a sub-arctic site along the Hudson Bay (Canada). Gas-phase measurements show that the snowmelt coincides with an elemental mercury (Hg°) pulse in the snowpack air far above ambient levels. Additional measurements of inorganic mercury (Hg2+) and methylmercury (MeHg+) in snow pits, in surface snow and in a meltwater sample clearly reveal that most of Hg is removed from the snow during the first days of snowmelt. We estimate that gas-phase exchanges contribute poorly to remove Hg from the snowpack; consequently during a snowmelt day more than 90% of Hg present in the snow surface is likely released with the meltwater. In arctic areas, where Hg accumulates at an accelerated rate in the snow surfaces [ Lu et al., 2001] during mercury depletion events (MDE), the discharge of this toxic and bio-accumulating pollutant in water systems could be a threat to ecosystems and local indigenous populations.

  6. Equating minimalist snowmelt and runoff generation models via validation with a wireless weather station network

    NASA Astrophysics Data System (ADS)

    Tobin, C. C.; Schaefli, B.; Nicotina, L.; Simoni, S.; Barrenetxea, G.; Parlange, M. B.; Rinaldo, A.

    2011-12-01

    A wireless network of 12 weather stations in the Val Ferret watershed (approximately 21 km2) in the Swiss Alps was used to validate snowmelt models with distributed temperature and radiation data. Using this extensive dataset, an improved yet simplistic degree-day method was compared with a radiation-based method proposed by Hock et al., 1999. The original degree-day approach is a widely used snowmelt model, relating snowmelt directly to air temperature. Numerous hydrological models use this minimalist approach due to its equivalent simplicity. Modifications of this simple method have been proposed in the past which typically incorporate local radiation conditions. However, these modifications generally require more data and/or a finer hydrological grid resolution. Results herein as well as theoretical considerations illustrate that the Hock point or grid-scale method is not always a robust method when combined with spatially explicit rainfall-runoff transformation models. This generalized hydrological application suggests that a simple diurnal cycle of the degree-day melt parameter has the potential to outperform the Hock local radiation-based approach for sub-daily melt simulations. We therefore suggest that the improved degree-day method enables a flexible melt modeling approach, which can be easily adapted into spatially-explicit hydrological models of varying complexity. Furthermore, as this new degree-day method is based upon solely daily temperature extremes, this approach is capable of being adapted for climate change predictions.

  7. Organochlorine pesticide and polychlorinated biphenyl concentrations in snow, snowmelt, and runoff at Bow Lake, Alberta.

    PubMed

    Lafrenière, Melissa J; Blais, Jules M; Sharp, Martin J; Schindler, David W

    2006-08-15

    We present analyses of the concentrations of organochlorine (OC) contaminants (including organochlorine pesticides and PCBs) in snow, snowmelt, and runoff in glacier and snowmelt fed streams at Bow Lake, Alberta in two contrasting hydrological years (1997 and 1998). The study investigates the variability in OC burdens in snow across the catchment, the elution of OCs from the snowpack, and the relationship between OC concentrations in streams and the annual snowpack. Snowpacks in forested sites were thinner and had lower OC concentrations than snowpacks in open or sparsely vegetated sites. The first snowmelt samples exhibited very high contaminant concentrations relative to the snowpack, and even the more hydrophobic compounds (Dieldrin, DDTs, and PCBs) were highly concentrated in meltwater. Interannual changes in the mean OC concentrations in streams did not reflect year-to-year changes in the snowpack contaminant concentrations. The results indicate that the extent of glacial ice melt may be more important than mean snowpack burdens as a control on OC concentrations in runoff in glacial catchments. PMID:16955885

  8. The Effect of Snowmelt on the Water Quality of Filson Creek and Omaday Lake, Northeastern Minnesota

    NASA Astrophysics Data System (ADS)

    Siegel, D. I.

    1981-01-01

    Sulfate concentration and pH were determined in surface water, groundwater, and precipitation samples collected in the Filson Creek watershed to evaluate the sources of sulfate in Filson Creek. During and immediately after snowmelt, sulfate concentrations in Filson Creek increased from about 2 to 14 mg/l. Concurrently, H+ ion activity increased from an average of 10-6.6 to 10-5.5. These changes suggest that sulfate acidity is concentrated in the snowpack at snowmelt, which is similar to changes reported in Scandinavia in areas subject to acid precipitation. Mass balance calculations indicate that the sulfate contribution from groundwater during snowmelt was minimal in comparison to that from snow. During base flow, sulfate did not appreciably increase from the headwaters of Filson Creek to the mouth, even though sulfate was as high as 58 mg/l in groundwater discharging to the creek from surficial materials overlying a sulfide-bearing mineralized zone in the lower third of the watershed. Approximately 10.6 kg of sulfate per hectare per year was retained in 1977.

  9. Concentrations and transport of different forms of phosphorus during snowmelt runoff from an illite clay soil

    NASA Astrophysics Data System (ADS)

    Ulén, Barbro

    2003-03-01

    During a 16 day period with pronounced snowmelt via surface runoff, high water concentrations (usually 0·4-0·5 mg l-1) of dissolved molybdate-reactive phosphorus (MRP) were detected in surface runoff water from a clay soil of illite type. Other phosphorus fractions defined were: phosphorus in particles with a higher settling coefficient than 80 000 S (SPP); colloidal phosphorus caught on filters with a pore size of 0·2 µm but with a smaller settling coefficient (CPP); and dissolved phosphorus not reacting with molybdate (DUP). The order of concentrations was MRP > SPP > CPP > DUP. Nearly identical amounts of MRP, CPP, and DUP (in total 0·3 kg ha-1) were lost from a grass-clover ley and a ploughed soil. However, more of the heavier phosphorus-containing material was lost from the ploughed area. In drainpipe water, CPP was the largest fraction (28%), and in stream water from mixed arable/forest land, MRP dominated (33%). Loss on ignition of the settling material slowly decreased from 10 to 8% (dry weight) during the snowmelt period. Total phosphorus concentrations in the material followed the runoff pattern, with slightly higher phosphorus concentrations during fast runoff. The large amounts of readily dissolved or colloidal-bound phosphorus (70-80%) transported from this clay soil during snowmelt are discussed with regard to the use of grass buffer strips as a measure against phosphorus losses from arable land.

  10. Use of MODIS Snow-Cover Maps for Detecting Snowmelt Trends in North America

    NASA Technical Reports Server (NTRS)

    Hall, Dorothy K.; Foster, James L.; Riggs, George A.; Robinson, David A.; Hoon-Starr, Jody A.

    2012-01-01

    Research has shown that the snow season in the Northern Hemisphere has been getting shorter in recent decades, consistent with documented global temperature increases. Specifically, the snow is melting earlier in the spring allowing for a longer growing season and associated land-cover changes. Here we focus on North America. Using the Moderate-Resolution Imaging Radiometer (MODIS) cloud-gap-filled standard snow-cover data product we can detect a trend toward earlier spring snowmelt in the approx 12 years since the MODIS launch. However, not all areas in North America show earlier spring snowmelt over the study period. We show examples of springtime snowmelt over North America, beginning in March 2000 and extending through the winter of 2012 for all of North America, and for various specific areas such as the Wind River Range in Wyoming and in the Catskill Mountains in New York. We also compare our approx 12-year trends with trends derived from the Rutgers Global Snow Lab snow cover climate-data record.

  11. Streamflow characterization using functional data analysis of the Potomac River

    NASA Astrophysics Data System (ADS)

    Zelmanow, A.; Maslova, I.; Ticlavilca, A. M.; McKee, M.

    2013-12-01

    Flooding and droughts are extreme hydrological events that affect the United States economically and socially. The severity and unpredictability of flooding has caused billions of dollars in damage and the loss of lives in the eastern United States. In this context, there is an urgent need to build a firm scientific basis for adaptation by developing and applying new modeling techniques for accurate streamflow characterization and reliable hydrological forecasting. The goal of this analysis is to use numerical streamflow characteristics in order to classify, model, and estimate the likelihood of extreme events in the eastern United States, mainly the Potomac River. Functional data analysis techniques are used to study yearly streamflow patterns, with the extreme streamflow events characterized via functional principal component analysis. These methods are merged with more classical techniques such as cluster analysis, classification analysis, and time series modeling. The developed functional data analysis approach is used to model continuous streamflow hydrographs. The forecasting potential of this technique is explored by incorporating climate factors to produce a yearly streamflow outlook.

  12. Seasonal streamflow prediction in Colombia using atmospheric and oceanic patterns

    NASA Astrophysics Data System (ADS)

    Córdoba-Machado, Samir; Palomino-Lemus, Reiner; Gámiz-Fortis, Sonia Raquel; Castro-Díez, Yolanda; Esteban-Parra, María Jesús

    2016-07-01

    The predictability of the Magdalena River seasonal streamflow anomalies is evaluated using previous Sea Surface Temperature (SST), Precipitation (Pt) and Temperature over land (Tm) seasonal anomalies. Through a moving correlation analysis of 30 years, several regions that show stable significant teleconnections between the seasonal streamflow and SST, Pt and Tm from previous seasons have been identified during the period 1936-2009. For lags from one to four 3-month seasons (i.e. up to one year) for the SST and one to two seasons (i.e. up to six months) for Pt and Tm, the Magdalena River seasonal streamflow presents significant and stable correlations with the tropical Pacific SST (El Niño region), with Pt in South America and with Tm over the north of South America, mainly at lags of one and two seasons. The first PCs resulting from the significant and stable regions of the SST, Pt, and Tm fields are used in a forecast scheme to predict seasonal streamflow anomalies. The prediction based on this scheme shows an acceptable prediction skill and represents a relative improvement compared with the predictability of teleconnection indices associated with El Niño, which are traditionally used to predict streamflow in the country. This improvement is particularly more noticeable when lag between streamflow and predictors increases.

  13. A proposed streamflow-data program for Utah

    USGS Publications Warehouse

    Whitaker, G.L.

    1970-01-01

    An evaluation of the streamflow data available in Utah was made to provide guidelines for planning future programs. The basic steps in the evaluation procedure were (1) definition of the long- term goals of the streamflow-data program in quantitative form, (2) examination and analysis of all available data to determine which goals have already been met, and (3) consideration of alternate programs and techniques to meet the remaining objectives. The principal goals are (1) to provide current streamflow data where needed for water management and (2) to define streamflow characteristics at any point on any stream within a specified accuracy. It was found that the first goal generally is being satisfied but that flow characteristics at ungaged sites cannot be estimated within the specified accuracy by regression analysis with the existing data and model now available. This latter finding indicates the need for some changes in the present data program so that the accuracy goals can be approached by alternate methods. The regression method may be more successful at a future time if a more suitable model can be developed, and if an adequate sample of streamflow records can be obtained in all areas. In the meantime, methods of transferring flow characteristics which require some information at the ungaged site may be used. A modified streamflow-data program based on this study is proposed.

  14. Sensitivity of streamflows to hydroclimatic fluctuations: resilience and regime shifts

    NASA Astrophysics Data System (ADS)

    Botter, Gianluca; Basso, Stefano; Rodriguez-Iturbe, Ignacio; Rinaldo, Andrea

    2016-04-01

    Landscape and climate alterations foreshadow global-scale shifts of river flow regimes. However, a theory that identifies the range of foreseen impacts on streamflows resulting from inhomogeneous forcings and sensitivity gradients across diverse regimes is lacking. In this contribution, we use a dimensionless index embedding simple climate and landscape attributes (the ratio of the mean interarrival of streamflow-producing rainfall events and the mean catchment response time) to discriminate erratic regimes with enhanced intra-seasonal streamflow variability from persistent regimes endowed with regular flow patterns. The proposed classification is successfully applied to 110 seasonal streamflow distributions observed in 44 catchments of the Alps and the United States, allowing the identification of emerging patterns in space and time. In the same framework, the impact of multi-scale fluctuations of the underlying climatic drivers (temperature, precipitation) on the streamflow distributions can be analyzed. Theoretical and empirical data show that erratic regimes, typical of rivers with low mean discharges, are highly resilient in that they hold a reduced sensitivity to variations in the external forcing. Specific temporal trajectories of streamflow distributions and flow regime shifts driven by land-cover change and rainfall patterns can be also evidenced. The approach developed offers an objective basis for the analysis and prediction of the impact of climate/landscape change on water resources.

  15. Substantial proportion of global streamflow less than three months old

    NASA Astrophysics Data System (ADS)

    Jasechko, Scott; Kirchner, James W.; Welker, Jeffrey M.; McDonnell, Jeffrey J.

    2016-02-01

    Biogeochemical cycles, contaminant transport and chemical weathering are regulated by the speed at which precipitation travels through landscapes and reaches streams. Streamflow is a mixture of young and old precipitation, but the global proportions of these young and old components are not known. Here we analyse seasonal cycles of oxygen isotope ratios in rain, snow and streamflow compiled from 254 watersheds around the world, and calculate the fraction of streamflow that is derived from precipitation that fell within the past two or three months. This young streamflow accounts for about a third of global river discharge, and comprises at least 5% of discharge in about 90% of the catchments we investigated. We conclude that, although typical catchments have mean transit times of years or even decades, they nonetheless can rapidly transmit substantial fractions of soluble contaminant inputs to streams. Young streamflow is less prevalent in steeper landscapes, which suggests they are characterized by deeper vertical infiltration. Because young streamflow is derived from less than 0.1% of global groundwater storage, we conclude that this thin veneer of aquifer storage will have a disproportionate influence on stream water quality.

  16. Assessing streamflow sensitivity to variations in glacier mass balance

    NASA Astrophysics Data System (ADS)

    Oneel, S.; Hood, E. W.; Arendt, A. A.; Sass, L. C.; March, R. S.

    2013-12-01

    We examine long-term streamflow and mass balance data from two Alaskan glaciers located in climatically distinct basins: Gulkana Glacier, a continental glacier located in the Alaska Range, and Wolverine Glacier, a maritime glacier located in the Kenai Mountains. Both glaciers lost mass, primarily as a result of summer warming, and both basins exhibit increasing streamflow over the 1966-2011 study interval. We estimated total glacier runoff via summer mass balance, and separated the fraction related to annual mass imbalances. In both climates, the fraction of streamflow related to annual mass balance averages less than 20%, substantially smaller than the fraction related to total summer mass loss (>50%), which occurs even in years of glacier growth. The streamflow fraction related to changes in annual mass balance has increased only in the continental environment. In the maritime climate, where deep winter snowpacks and frequent rain events drive consistently high runoff, the magnitude of this streamflow fraction is small and highly variable, precluding detection of any existing trend. Changes in streamflow related to annual balance are often masked by interannual variability of maritime glacier mass balance, such that predicted scenarios of continued glacier recession are more likely to impact the quality and timing of runoff than the total basin water yield.

  17. A national streamflow network gap analysis

    USGS Publications Warehouse

    Kiang, Julie E.; Stewart, David W.; Archfield, Stacey A.; Osborne, Emily B.; Eng, Ken

    2013-01-01

    The U.S. Geological Survey (USGS) conducted a gap analysis to evaluate how well the USGS streamgage network meets a variety of needs, focusing on the ability to calculate various statistics at locations that have streamgages (gaged) and that do not have streamgages (ungaged). This report presents the results of analysis to determine where there are gaps in the network of gaged locations, how accurately desired statistics can be calculated with a given length of record, and whether the current network allows for estimation of these statistics at ungaged locations. The analysis indicated that there is variability across the Nation’s streamflow data-collection network in terms of the spatial and temporal coverage of streamgages. In general, the Eastern United States has better coverage than the Western United States. The arid Southwestern United States, Alaska, and Hawaii were observed to have the poorest spatial coverage, using the dataset assembled for this study. Except in Hawaii, these areas also tended to have short streamflow records. Differences in hydrology lead to differences in the uncertainty of statistics calculated in different regions of the country. Arid and semiarid areas of the Central and Southwestern United States generally exhibited the highest levels of interannual variability in flow, leading to larger uncertainty in flow statistics. At ungaged locations, information can be transferred from nearby streamgages if there is sufficient similarity between the gaged watersheds and the ungaged watersheds of interest. Areas where streamgages exhibit high correlation are most likely to be suitable for this type of information transfer. The areas with the most highly correlated streamgages appear to coincide with mountainous areas of the United States. Lower correlations are found in the Central United States and coastal areas of the Southeastern United States. Information transfer from gaged basins to ungaged basins is also most likely to be successful

  18. A Hierarchy of Snowmelt Models for Canadian Prairies: Temperature-Index, Modified Temperature Index and Energy-Balance Models

    NASA Astrophysics Data System (ADS)

    Yew Gan, Thian; Singh, Purushottam; Gobena, Adam

    2010-05-01

    Three semi-distributed snowmelt models were developed and applied to the Paddle River Basin (PRB) in the Canadian Prairies: (1) A physics-based, energy balance model (SDSM-EBM) that considers vertical energy exchange processes in open and forested areas, and snowmelt processes that include liquid and ice phases separately; (2) A modified temperature index model (SDSM-MTI) that uses both near surface soil temperature (Tg) and air temperature (Ta), and (3) A standard temperature index(SDSM-TI) method using Ta only. Other than the "regulatory" effects of beaver dams that affected the validation results on simulated runoff, both SDSM-MTI and SDSM EBM simulated reasonably accurate snowmelt runoff, snow water equivalent and snow depth. For the PRB, where snowpack is shallow to moderately deep, and winter is relatively severe, the advantage of using both Ta and Tg is partly attributed to Tg showing a stronger correlation with solar radiation than Ta during the spring snowmelt season, and partly to the onset of major snowmelt which usually happens when Tg approaches 0oC. After re-setting model parameters so that SDSM-MTI degenerated to SDSM-TI (effect of Tg is completely removed), the latter performed poorly, even after re-calibrating the melt factors using Ta alone. It seems that if reliable Tg data are available, they should be utilized to model the snowmelt processes in a Prairie environment particularly if the temperature-index approach is adopted.

  19. A Hierarchy of Snowmelt Models for Canadian Prairies: Temperature-Index, Modified Temperature Index and Energy-Balance Models

    NASA Astrophysics Data System (ADS)

    Gan, T. Y.

    2009-04-01

    Three semi-distributed snowmelt models were developed and applied to the Paddle River Basin (PRB) in the Canadian Prairies: (1) A physics-based, energy balance model (SDSM-EBM) that considers vertical energy exchange processes in open and forested areas, and snowmelt processes that include liquid and ice phases separately; (2) A modified temperature index model (SDSM-MTI) that uses both near surface soil temperature (Tg) and air temperature (Ta), and (3) A standard temperature index (SDSM-TI) method using Ta only. Other than the "regulatory" effects of beaver dams that affected the validation results on simulated runoff, both SDSM-MTI and SDSM-EBM simulated reasonably accurate snowmelt runoff, snow water equivalent and snow depth. For the PRB, where snowpack is shallow to moderately deep, and winter is relatively severe, the advantage of using both Ta and Tg is partly attributed to Tg showing a stronger correlation with solar radiation than Ta during the spring snowmelt season, and partly to the onset of major snowmelt which usually happens when Tg approaches 0oC. After re-setting model parameters so that SDSM-MTI degenerated to SDSM-TI (effect of Tg is completely removed), the model performance worsened, even after re-calibrating the melt factors using Ta alone. It seems that if reliable Tg data are available, they should be utilized to model the snowmelt processes in a Prairie environment particularly if the temperature-index approach is adopted.

  20. Atlantic influences on Eastern U.S. Summer Streamflow

    NASA Astrophysics Data System (ADS)

    Budikova, D.; Coleman, J. S.

    2012-12-01

    Numerous studies have suggested that streamflow discharge in the conterminous U.S. has been increasing, particularly in the east starting in the latter half of the 20th century. Northern Hemisphere hydroclimatic variability has been connected to shifts in large-scale atmospheric teleconnection patterns. This study ascertained the spatial and temporal influences of the extreme phases of the North Atlantic Oscillation (NAO) on interannual streamflow variability across the eastern U.S during the summer season. We also assessed the presence of any delayed streamflow responses to NAO configurations during previous spring (MAM) and winter (DJF) seasons across the study area. Methods of inquiry included the use of various statistical and compositing analyses applied to records of mean daily summer streamflow obtained from the Hydro-Climatic Data Network between 1950 and 2010. Statistically significant relationships between summer streamflow and NAO during the previous winter were identified across the Upper and Lower Mississippi River basins and in the Northeast. These relationships are largely non-linear with majority of the streamflow response being associated with negative NAO winters coincidental with lower-than-expected streamflow conditions in all three areas. Outside the Northeast, the winter NAO/summer streamflow relationships are driven to a large extent by the presence of an upward trend in the winter index. Spring NAO conditions influence summer streamflow throughout the eastern Great Lakes region where higher-than-expected (lower-than-expected) streamflows trail positive (negative) phases of the NAO. The responses are, however, most pronounced during the positive phase of the NAO both in terms of the spatial extent as well as magnitude of impact. The influence of summer NAO on concurrent streamflow is most evident along the coast, east of the Appalachian mountain range and in Indiana. Strongest responses are observed during the negative phase of the NAO across

  1. Streamflow characteristics based on data through water year 2009 for selected streamflow-gaging stations in or near Montana: Chapter E in Montana StreamStats

    USGS Publications Warehouse

    McCarthy, Peter M.

    2016-01-01

    Chapter E of this Scientific Investigations Report documents results from a study by the U.S. Geological Survey, in cooperation with the Montana Department of Environmental Quality and the Montana Department of Natural Resources and Conservation, to provide an update of statewide streamflow characteristics based on data through water year 2009 for streamflow-gaging stations in or near Montana. Streamflow characteristics are presented for 408 streamflow-gaging stations in Montana and adjacent areas having 10 or more years of record. Data include the magnitude and probability of annual low and high streamflow, the magnitude and probability of low streamflow for three seasons (March–June, July–October, and November–February), streamflow duration statistics for monthly and annual periods, and mean streamflows for monthly and annual periods. Streamflow is considered to be regulated at streamflow-gaging stations where dams or other large-scale human modifications affect 20 percent or more of the contributing drainage basin. Separate streamflow characteristics are presented for the unregulated and regulated periods of record for streamflow-gaging stations with sufficient data.

  2. Analysis of the streamflow-gaging station network in Ohio for effectiveness in providing regional streamflow information

    USGS Publications Warehouse

    Straub, D.E.

    1998-01-01

    The streamflow-gaging station network in Ohio was evaluated for its effectiveness in providing regional streamflow information. The analysis involved application of the principles of generalized least squares regression between streamflow and climatic and basin characteristics. Regression equations were developed for three flow characteristics: (1) the instantaneous peak flow with a 100-year recurrence interval (P100), (2) the mean annual flow (Qa), and (3) the 7-day, 10-year low flow (7Q10). All active and discontinued gaging stations with 5 or more years of unregulated-streamflow data with respect to each flow characteristic were used to develop the regression equations. The gaging-station network was evaluated for the current (1996) condition of the network and estimated conditions of various network strategies if an additional 5 and 20 years of streamflow data were collected. Any active or discontinued gaging station with (1) less than 5 years of unregulated-streamflow record, (2) previously defined basin and climatic characteristics, and (3) the potential for collection of more unregulated-streamflow record were included in the network strategies involving the additional 5 and 20 years of data. The network analysis involved use of the regression equations, in combination with location, period of record, and cost of operation, to determine the contribution of the data for each gaging station to regional streamflow information. The contribution of each gaging station was based on a cost-weighted reduction of the mean square error (average sampling-error variance) associated with each regional estimating equation. All gaging stations included in the network analysis were then ranked according to their contribution to the regional information for each flow characteristic. The predictive ability of the regression equations developed from the gaging station network could be improved for all three flow characteristics with the collection of additional streamflow data

  3. Streamflow input to Lake Athabasca, Canada

    NASA Astrophysics Data System (ADS)

    Rasouli, K.; Hernández-Henríquez, M. A.; Déry, S. J.

    2013-05-01

    The Lake Athabasca drainage area in northern Canada encompasses ecologically rich and sensitive ecosystems, vast forests, glacier-clad mountains, and abundant oil reserves in the form of oil sands. The basin includes the Peace-Athabasca Delta, recognized internationally by UNESCO and the Ramsar Convention as a biologically rich inland delta and wetland that are now under increasing pressure from multiple stressors. In this study, streamflow variability and trends for rivers feeding Lake Athabasca are investigated over the last half century. Hydrological regimes and trends are established using a robust regime shift detection method and the Mann-Kendall (MK) test, respectively. Results show that the Athabasca River, which is the main contributor to the total lake inflow, experienced marked declines in recent decades impacting lake levels and its ecosystem. From 1960 to 2010 there was a significant reduction in lake inflow and a significant recession in the Lake Athabasca level. Our trend analysis corroborates a previous study using proxy data obtained from nearby sediment cores suggesting that the lake level may drop 2 to 3 m by 2100. The lake recession may threaten the flora and fauna of the Athabasca Lake basin and negatively impact the ecological cycle of an inland freshwater delta and wetland of global importance.

  4. Evaluation of ensemble streamflow predictions in Europe

    NASA Astrophysics Data System (ADS)

    Alfieri, Lorenzo; Pappenberger, Florian; Wetterhall, Fredrik; Haiden, Thomas; Richardson, David; Salamon, Peter

    2014-09-01

    In operational hydrological forecasting systems, improvements are directly related to the continuous monitoring of the forecast performance. An efficient evaluation framework must be able to spot issues and limitations and provide feedback to the system developers. In regional systems, the expertise of analysts on duty is a major component of the daily evaluation. On the other hand, large scale systems need to be complemented with semi-automated tools to evaluate the quality of forecasts equitably in every part of their domain. This article presents the current status of the monitoring and evaluation framework of the European Flood Awareness System (EFAS). For each grid point of the European river network, 10-day ensemble streamflow predictions are evaluated against a reference simulation which uses observed meteorological fields as input to a calibrated hydrological model. Performance scores are displayed over different regions, forecast lead times, basin sizes, as well as in time, considering average scores for moving 12-month windows of forecasts. Skilful predictions are found in medium to large rivers over the whole 10-day range. On average, performance drops significantly in river basins with upstream area smaller than 300 km2, partly due to underestimation of the runoff in mountain areas. Model limitations and recommendations to improve the evaluation framework are discussed in the final section.

  5. Simulating the evolution of seasonal snowcover and snowmelt runoff using a distributed energy balance model: Application to an alpine watershed in the Tobacco Root Mountains, Montana

    NASA Astrophysics Data System (ADS)

    Letsinger, Sally Libbey

    A distributed energy-balance model was developed for simulating the seasonal snowmelt in rugged alpine terrain and applied to a 45 km2 headwater catchment in the Tobacco Root Mountains, Montana. Micrometeorological data that were collected over the 1997--1998 snow-accumulation and snowmelt seasons were used as boundary conditions for estimating initial snow distributions as well as calculating the timing and distribution of snowmelt from the basin. Simulated snowmelt volumes compare favorably with measured outflow from a stream gage located just downstream of the study area. Results of this study demonstrate that the representation of heterogeneity in complex terrain produces realistic energy and resultant snow-cover distributions throughout the snowmelt season. As in many other studies, the patterns of snowmelt were highly correlated to the distribution of net radiation in the watershed. Although the primary control on snowmelt patterns was net radiation, the initial distribution of snow-water equivalent was also a dominant factor. Snowmelt from individual subcatchments in the study area produces inflow hydrographs that reflect the heterogeneous attributes of terrain and ground cover that characterize each sub-basin. Season-long simulations were also conducted using simplifying assumptions of isotropy in calculating the diffuse irradiance components in the energy-balance snowmelt model. Results from the simulations using isotropic assumptions were compared to the energy-balance snowmelt model, which assumes that diffuse irradiances are anisotropic. The amount of calculated snowmelt varied between the two methods, suggesting that isotropic assumptions could account for underestimation of as much as 106 cubic meters of snowmelt over a single season. These results indicate that the assumption of isotropic conditions appears to be suitable for representation of areas with little surrounding topographic influence but not for areas of rugged terrain that constitute most

  6. An analysis of MODIS fractional snow cover estimates for snowmelt runoff modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rio Grande streamflow is fed primarily by water from the melting snowpack in mountainous basins in the Southern Rockies. The snowpack accumulates mass in winter months and melts continuously through Spring and Summer. It is estimated that snowpack contributes 50% of the annual water supply of Colora...

  7. Aquatic Species Responses to Changes in Streamflow and Stream Temperature in the Willamette River Basin of Oregon

    NASA Astrophysics Data System (ADS)

    Chang, H.; Psaris, A. M.; Strecker, A.

    2014-12-01

    Climate models project less summer precipitation and hotter temperatures in the Pacific Northwest. These changes will bring earlier snowmelt and reduced summer flow, which will increase stream temperature. Many cold water species will be adversely affected by such changes. However, the spatial and temporal extent of how each stream responds to climate change and how fish species respond to varying degrees of changes in flow and stream temperature across multiple streams has not been thoroughly studied. Using a combination of representative downscaled climate data, a watershed hydrologic model, and regression analysis, we projected future changes in streamflow and temperature and the responses of fish habitat to these changes for several tributaries of the Willamette River basin that exhibits distinct hydrologic landscape regions. Our simulation results suggest that streams located in the High Cascades where groundwater input is high will experience less warming and less flow reduction, thus more resilient to warming. In contrast, streams in transient areas where snow cover is projected to decline substantially will experience the most declines in fish diversity as a result of reduction in flow and highest rise in stream temperature. Our results suggest spatially targeted adaptive management strategies for fishes in a large heterogeneous river basin will be necessary in a rapidly changing climate.

  8. Biotic and abiotic processes controlling water chemistry during snowmelt at rabbit ears pass, Rocky Mountains, Colorado, U.S.A.

    USGS Publications Warehouse

    Peters, N.E.; Leavesley, G.H.

    1995-01-01

    The chemical composition of snowmelt, groundwater, and streamwater was monitored during the spring of 1991 and 1992 in a 200-ha subalpine catchment on the western flank of the Rocky Mountains near Steamboat Springs, Colorado. Most of the snowmelt occurred during a one-month period annually that began in mid-May 1991 and mid-April 1992. The average water quality characteristics of individual sampling sites (meltwater, streamwater, and groundwater) were similar in 1991 and 1992. The major ions in meltwater were differentially eluted from the snowpack, and meltwater was dominated by Ca2+, SO4/2-, and NO3/-. Groundwater and streamwater were dominated by weathering products, including Ca2+, HCO3/- (measured as alkalinity), and SiO2, and their concentrations decreased as snowmelt progressed. One well had extremely high NO3/- concentrations, which were balanced by Ca2+ concentrations. For this well, hydrogen ion was hypothesized to be generated from nitrification in overlying soils, and subsequently exchanged with other cations, particularly Ca2+. Solute concentrations in streamwater also decreased as snowmelt progressed. Variations in groundwater levels and solute concentrations indicate thai most of the meltwater traveled through the surficial materials. A mass balance for 1992 indicated that the watershed retained H+, NH4/+, NO3/-, SO4/2- and Cl- and was the primary source of base cations and other weathering products. Proportionally more SO4/2- was deposited with the unusually high summer rainfall in 1992 compared to that released from snowmelt, whereas NO3/- was higher in snowmelt and Cl- was the same. The sum of snowmelt and rainfall could account for greater than 90% of the H+ and NH4/+ retained by the watershed and greater than 50% of the NO3/-.The chemical composition of snowmelt, groundwater, and streamwater was monitored during the spring of 1991 and 1992 in a 200-ha subalpine catchment on the western flank of the Rocky Mountains near Steamboat Springs

  9. Streamflow impacts of biofuel policy-driven landscape change.

    PubMed

    Khanal, Sami; Anex, Robert P; Anderson, Christopher J; Herzmann, Daryl E

    2014-01-01

    Likely changes in precipitation (P) and potential evapotranspiration (PET) resulting from policy-driven expansion of bioenergy crops in the United States are shown to create significant changes in streamflow volumes and increase water stress in the High Plains. Regional climate simulations for current and biofuel cropping system scenarios are evaluated using the same atmospheric forcing data over the period 1979-2004 using the Weather Research Forecast (WRF) model coupled to the NOAH land surface model. PET is projected to increase under the biofuel crop production scenario. The magnitude of the mean annual increase in PET is larger than the inter-annual variability of change in PET, indicating that PET increase is a forced response to the biofuel cropping system land use. Across the conterminous U.S., the change in mean streamflow volume under the biofuel scenario is estimated to range from negative 56% to positive 20% relative to a business-as-usual baseline scenario. In Kansas and Oklahoma, annual streamflow volume is reduced by an average of 20%, and this reduction in streamflow volume is due primarily to increased PET. Predicted increase in mean annual P under the biofuel crop production scenario is lower than its inter-annual variability, indicating that additional simulations would be necessary to determine conclusively whether predicted change in P is a response to biofuel crop production. Although estimated changes in streamflow volume include the influence of P change, sensitivity results show that PET change is the significantly dominant factor causing streamflow change. Higher PET and lower streamflow due to biofuel feedstock production are likely to increase water stress in the High Plains. When pursuing sustainable biofuels policy, decision-makers should consider the impacts of feedstock production on water scarcity. PMID:25289698

  10. Ranking streamflow model performance based on Information theory metrics

    NASA Astrophysics Data System (ADS)

    Martinez, Gonzalo; Pachepsky, Yakov; Pan, Feng; Wagener, Thorsten; Nicholson, Thomas

    2016-04-01

    The accuracy-based model performance metrics not necessarily reflect the qualitative correspondence between simulated and measured streamflow time series. The objective of this work was to use the information theory-based metrics to see whether they can be used as complementary tool for hydrologic model evaluation and selection. We simulated 10-year streamflow time series in five watersheds located in Texas, North Carolina, Mississippi, and West Virginia. Eight model of different complexity were applied. The information-theory based metrics were obtained after representing the time series as strings of symbols where different symbols corresponded to different quantiles of the probability distribution of streamflow. The symbol alphabet was used. Three metrics were computed for those strings - mean information gain that measures the randomness of the signal, effective measure complexity that characterizes predictability and fluctuation complexity that characterizes the presence of a pattern in the signal. The observed streamflow time series has smaller information content and larger complexity metrics than the precipitation time series. Watersheds served as information filters and and streamflow time series were less random and more complex than the ones of precipitation. This is reflected the fact that the watershed acts as the information filter in the hydrologic conversion process from precipitation to streamflow. The Nash Sutcliffe efficiency metric increased as the complexity of models increased, but in many cases several model had this efficiency values not statistically significant from each other. In such cases, ranking models by the closeness of the information-theory based parameters in simulated and measured streamflow time series can provide an additional criterion for the evaluation of hydrologic model performance.

  11. Statistical downscaling for winter streamflow in Douro River

    NASA Astrophysics Data System (ADS)

    Jesús Esteban Parra, María; Hidalgo Muñoz, José Manuel; García-Valdecasas-Ojeda, Matilde; Raquel Gámiz Fortis, Sonia; Castro Díez, Yolanda

    2015-04-01

    In this paper we have obtained climate change projections for winter flow of the Douro River in the period 2071-2100 by applying the technique of Partial Regression and various General Circulation Models of CMIP5. The streamflow data base used has been provided by the Center for Studies and Experimentation of Public Works, CEDEX. Series from gauing stations and reservoirs with less than 10% of missing data (filled by regression with well correlated neighboring stations) have been considered. The homogeneity of these series has been evaluated through the Pettit test and degree of human alteration by the Common Area Index. The application of these criteria led to the selection of 42 streamflow time series homogeneously distributed over the basin, covering the period 1951-2011. For these streamflow data, winter seasonal values were obtained by averaging the monthly values from January to March. Statistical downscaling models for the streamflow have been fitted using as predictors the main atmospheric modes of variability over the North Atlantic region. These modes have been obtained using winter sea level pressure data of the NCEP reanalysis, averaged for the months from December to February. Period 1951-1995 was used for calibration, while 1996-2011 period was used in validating the adjusted models. In general, these models are able to reproduce about 70% of the variability of the winter streamflow of the Douro River. Finally, the obtained statistical models have been applied to obtain projections for 2071-2100 period, using outputs from different CMIP5 models under the RPC8.5 scenario. The results for the end of the century show modest declines of winter streamflow in this river for most of the models. Keywords: Statistical downscaling, streamflow, Douro River, climate change. ACKNOWLEDGEMENTS This work has been financed by the projects P11-RNM-7941 (Junta de Andalucía-Spain) and CGL2013-48539-R (MINECO-Spain, FEDER).

  12. Sensitivity of streamflow to climate change in California

    NASA Astrophysics Data System (ADS)

    Grantham, T.; Carlisle, D.; Wolock, D.; McCabe, G. J.; Wieczorek, M.; Howard, J.

    2015-12-01

    Trends of decreasing snowpack and increasing risk of drought are looming challenges for California water resource management. Increasing vulnerability of the state's natural water supplies threatens California's social-economic vitality and the health of its freshwater ecosystems. Despite growing awareness of potential climate change impacts, robust management adaptation has been hindered by substantial uncertainty in future climate predictions for the region. Down-scaled global climate model (GCM) projections uniformly suggest future warming of the region, but projections are highly variable with respect to the direction and magnitude of change in regional precipitation. Here we examine the sensitivity of California surface water supplies to climate variation independently of GCMs. We use a statistical approach to construct predictive models of monthly streamflow based on historical climate and river basin features. We then propagate an ensemble of synthetic climate simulations through the models to assess potential streamflow responses to changes in temperature and precipitation in different months and regions of the state. We also consider the range of streamflow change predicted by bias-corrected downscaled GCMs. Our results indicate that the streamflow in the xeric and coastal mountain regions of California is more sensitive to changes in precipitation than temperature, whereas streamflow in the interior mountain region responds strongly to changes in both temperature and precipitation. Mean climate projections for 2025-2075 from GCM ensembles are highly variable, indicating streamflow changes of -50% to +150% relative to baseline (1980-2010) for most months and regions. By quantifying the sensitivity of streamflow to climate change, rather than attempting to predict future hydrologic conditions based on uncertain GCM projections, these results should be more informative to water managers seeking to assess, and potentially reduce, the vulnerability of surface

  13. Hydrologic Analysis for Kankakee River Watershed Streamflow Accounting Model

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Knapp, H. V.

    2014-12-01

    Streamflow frequency is used for in-stream flow needs evaluation, water supply planning, water quality analysis, and stream classification, among other purposes. The Illinois Streamflow Accounting Model (ILSAM) was developed to predict the streamflow frequency for Illinois streams and has the capacity to explore anthropogenic impacts on streamflow frequency. Over the past two decades, ILSAM has been applied to ten major watersheds in Illinois. This study updates the hydrologic analysis for the Kankakee River watershed. The hydrologic analyses used to develop the model involved evaluating streamflow records from gaging stations and developing regional equations to estimate flows at ungaged sites throughout the watersheds. Impacts to flow quantity from dams, water supplies, and treated wastewater effluents are examined. The baseline flow condition is the flow record at gaged sites which includes historic anthropogenic effects. The unaltered flow condition, influenced primarily by climate, topography, hydrogeology, and land use, is determined by separating the effects of historic human impact. The effects of the various human modifications to flow in the basin have changed substantially over the history of the available streamflow records. The present flow condition is determined by assuming that current human impact extends back throughout the history of available streamflow records, and statistical estimates are computed accordingly. Flow frequency estimates for each gaging record are adjusted to account for differences in the period of record and other factors such as the hydrologic persistence of low flow. For ungaged sites, a regional regression based on unaltered flow conditions is developed to estimate flow frequency, and adjustments are made to account for human impacts to represent the present flow condition for all sites.

  14. Streamflow Impacts of Biofuel Policy-Driven Landscape Change

    PubMed Central

    Khanal, Sami; Anex, Robert P.; Anderson, Christopher J.; Herzmann, Daryl E.

    2014-01-01

    Likely changes in precipitation (P) and potential evapotranspiration (PET) resulting from policy-driven expansion of bioenergy crops in the United States are shown to create significant changes in streamflow volumes and increase water stress in the High Plains. Regional climate simulations for current and biofuel cropping system scenarios are evaluated using the same atmospheric forcing data over the period 1979–2004 using the Weather Research Forecast (WRF) model coupled to the NOAH land surface model. PET is projected to increase under the biofuel crop production scenario. The magnitude of the mean annual increase in PET is larger than the inter-annual variability of change in PET, indicating that PET increase is a forced response to the biofuel cropping system land use. Across the conterminous U.S., the change in mean streamflow volume under the biofuel scenario is estimated to range from negative 56% to positive 20% relative to a business-as-usual baseline scenario. In Kansas and Oklahoma, annual streamflow volume is reduced by an average of 20%, and this reduction in streamflow volume is due primarily to increased PET. Predicted increase in mean annual P under the biofuel crop production scenario is lower than its inter-annual variability, indicating that additional simulations would be necessary to determine conclusively whether predicted change in P is a response to biofuel crop production. Although estimated changes in streamflow volume include the influence of P change, sensitivity results show that PET change is the significantly dominant factor causing streamflow change. Higher PET and lower streamflow due to biofuel feedstock production are likely to increase water stress in the High Plains. When pursuing sustainable biofuels policy, decision-makers should consider the impacts of feedstock production on water scarcity. PMID:25289698

  15. Application of a land surface model for simulating river streamflow in high latitudes

    NASA Astrophysics Data System (ADS)

    Gusev, Yeugeniy; Nasonova, Olga; Dzhogan, Larissa

    2010-05-01

    Nowadays modelling runoff from the pan-Arctic river basins, which represents nearly 50% of water flow to the Arctic Ocean, is of great interest among hydrological modelling community because these regions are very sensitive to natural and anthropogenic impacts. This motivates the necessity of increase of the accuracy of hydrological estimations, runoff predictions, and water resources assessments in high latitudes. However, in these regions, observations required for model simulations (to specify model parameters and forcing inputs) are very scarce or even absent (especially this concerns land surface parameters). At the same time river discharge measurements are usually available that makes it possible to estimate model parameters by their calibration against measured discharge. Such a situation is typical of most of the northern basins of Russia. The major goal of the work is to reveal whether a physically-based land surface model (LSM) Soil Water - Atmosphere - Plants (SWAP) is able to reproduce snowmelt and rain driven daily streamflow in high latitudes (using poor input information) with the accuracy acceptable for hydrologic applications. Three river basins, located on the north of the European part of Russia, were chosen for investigation. They are the Mezen River basin (area: area: 78 000 km2), the Pechora River basin (area: 312 000 km2) and the Severnaya Dvina River basin (area: 348 000 km2). For modeling purposes the basins were presented, respectively, by 10, 57 and 62 one-degree computational grid boxes connected by river network. A priori estimation of the land surface parameters for each grid box was based on the global one-degree datasets prepared within the framework of the International Satellite Land-Surface Climatology Project Initiative II (ISLSCP) / the Second Global Soil Wetness Project (GSWP-2). Three versions of atmospheric forcing data prepared for the basins were based on: (1) NCEP/DOE reanalysis dataset; (2) NCEP/DOE reanalysis product

  16. Measurement of Hydrologic Streamflow Metrics and Estimation of Streamflow with Lumped Parameter Models in a Managed Lake System, Sebago Lake, Maine

    NASA Astrophysics Data System (ADS)

    Reeve, A. S.; Martin, D.; Smith, S. M.

    2013-12-01

    Surface waters within the Sebago Lake watershed (southern Maine, USA) provide a variety of economically and intrinsically valuable recreational, commercial and environmental services. Different stakeholder groups for the 118 km2 Sebago Lake and surrounding watershed advocate for different lake and watershed management strategies, focusing on the operation of a dam at the outflow from Sebago Lake. While lake level in Sebago Lake has been monitored for over a century, limited data is available on the hydrologic processes that drive lake level and therefore impact how dam operation (and other changes to the region) will influence the hydroperiod of the lake. To fill this information gap several tasks were undertaken including: 1) deploying data logging pressure transducers to continuously monitor stream stage in nine tributaries, 2) measuring stream discharge at these sites to create rating curves for the nine tributaries, and using the resulting continuous discharge records to 3) calibrate lumped parameter computer models based on the GR4J model, modified to include a degree-day snowmelt routine. These lumped parameter models have been integrated with a simple lake water-balance model to estimate lake level and its response to different scenarios including dam management strategies. To date, about three years of stream stage data have been used to estimate stream discharge in all monitored tributaries (data collection is ongoing). Baseflow separation indices (BFI) for 2010 and 2011 using the USGS software PART and the Eckhart digital filter in WHAT range from 0.80-0.86 in the Crooked River and Richmill Outlet,followed by Northwest (0.75) and Muddy (0.53-0.56) Rivers, with the lowest BFI measured in Sticky River (0.41-0.56). The BFI values indicate most streams have significant groundwater (or other storage) inputs. The lumped parameter watershed model has been calibrated for four streams (Nash-Sutcliffe = 0.4 to 0.9), with the other major tributaries containing

  17. Influence of Snowmelt Timing on the Diet Quality of Pyrenean Rock Ptarmigan (Lagopus muta pyrenaica): Implications for Reproductive Success

    PubMed Central

    García-González, Ricardo; Aldezabal, Arantza; Laskurain, Nere Amaia; Margalida, Antoni; Novoa, Claude

    2016-01-01

    The Pyrenean rock ptarmigan (Lagopus muta pyrenaica) is the southernmost subspecies of the species in Europe and is considered threatened as a consequence of changes in landscape, human pressure, climate change, and low genetic diversity. Previous studies have shown a relationship between the date of snowmelt and reproductive success in the Pyrenean ptarmigan. It is well established that birds laying early in the breeding season have higher reproductive success, but the specific mechanism for this relationship is debated. We present an explicative model of the relationship between snowmelt date and breeding success mediated by food quality for grouse in alpine environments. From microhistological analyses of 121 faecal samples collected during three years in the Canigou Massif (Eastern Pyrenees), and the assessment of the chemical composition of the main dietary components, we estimated the potential quality of individual diets. Potential dietary quality was correlated with free-urate faecal N, a proxy of the digestible protein content ingested by ptarmigan, and both were correlated with phenological stage of consumed plants, which in turn depends on snowmelt date. Our findings suggest that the average snowmelt date is subject to a strong interannual variability influencing laying date. In years of early snowmelt, hens benefit from a longer period of high quality food resources potentially leading to a higher breeding success. On the contrary, in years of late snowmelt, hens begin their breeding period in poorer nutrient condition because the peaks of protein content of their main food items are delayed with respect to laying date, hence reducing breeding performance. We discuss the possible mismatch between breeding and snowmelt timing. PMID:26849356

  18. Influence of Snowmelt Timing on the Diet Quality of Pyrenean Rock Ptarmigan (Lagopus muta pyrenaica): Implications for Reproductive Success.

    PubMed

    García-González, Ricardo; Aldezabal, Arantza; Laskurain, Nere Amaia; Margalida, Antoni; Novoa, Claude

    2016-01-01

    The Pyrenean rock ptarmigan (Lagopus muta pyrenaica) is the southernmost subspecies of the species in Europe and is considered threatened as a consequence of changes in landscape, human pressure, climate change, and low genetic diversity. Previous studies have shown a relationship between the date of snowmelt and reproductive success in the Pyrenean ptarmigan. It is well established that birds laying early in the breeding season have higher reproductive success, but the specific mechanism for this relationship is debated. We present an explicative model of the relationship between snowmelt date and breeding success mediated by food quality for grouse in alpine environments. From microhistological analyses of 121 faecal samples collected during three years in the Canigou Massif (Eastern Pyrenees), and the assessment of the chemical composition of the main dietary components, we estimated the potential quality of individual diets. Potential dietary quality was correlated with free-urate faecal N, a proxy of the digestible protein content ingested by ptarmigan, and both were correlated with phenological stage of consumed plants, which in turn depends on snowmelt date. Our findings suggest that the average snowmelt date is subject to a strong interannual variability influencing laying date. In years of early snowmelt, hens benefit from a longer period of high quality food resources potentially leading to a higher breeding success. On the contrary, in years of late snowmelt, hens begin their breeding period in poorer nutrient condition because the peaks of protein content of their main food items are delayed with respect to laying date, hence reducing breeding performance. We discuss the possible mismatch between breeding and snowmelt timing. PMID:26849356

  19. Streamflow input to Lake Athabasca, Canada

    NASA Astrophysics Data System (ADS)

    Rasouli, K.; Hernández-Henríquez, M. A.; Déry, S. J.

    2012-08-01

    The 271 000 km2 Lake Athabasca drainage in Northern Canada encompasses ecologically-rich and sensitive ecosystems, intensive agricultural lands, vast forests, glacier-clad mountains, and abundant oil reserves in the form of tar-sands. In this study, streamflow variability and trends in eight rivers feeding the 7800 km2 Lake Athabasca are investigated over the period 1960-2010. Hydrological regimes and trends are established using a robust regime shift detection method and the Mann-Kendall (MK) test, respectively. Results show that the Athabasca River, which provides ~ 57% of the total annual lake inflow of 34.06 km3 yr-1, experiences marked declines in recent decades impacting lake levels and its ecosystem. The Fond du Lac River, which contributes ~ 30% of total Lake Athabasca inflow, has an increasing trend of 0.021 km3 yr-1 over 1970-2010 according to the MK test, equating to a 0.86 km3 discharge increase from Fond du Lac River to the lake. From 1960 to 2010 there has been approximately a 21.2% reduction of average discharge equivalent to a 7.22 km3 recession in the Lake Athabasca causing lake levels to drop. The lake level has a trend of -0.008 m yr-1 which is equivalent to a 0.39 m decline in the lake level over 1960-2010. The total lake inflow trend over 1977-2010 is -0.207 km3 yr-1 or a reduction of 25.67 km3 by 2100 by linear extrapolation. This may imply a further reduction of 2 m to 3 m in lake level that is in the range of a 5200-yr historical minimum inferred from proxy data in nearby sediment cores.

  20. Improving Streamflow Forecasts Using Predefined Sea Surface Temperature

    NASA Astrophysics Data System (ADS)

    Kalra, A.; Ahmad, S.

    2011-12-01

    With the increasing evidence of climate variability, water resources managers in the western United States are faced with greater challenges of developing long range streamflow forecast. This is further aggravated by the increases in climate extremes such as floods and drought caused by climate variability. Over the years, climatologists have identified several modes of climatic variability and their relationship with streamflow. These climate modes have the potential of being used as predictor in models for improving the streamflow lead time. With this as the motivation, the current research focuses on increasing the streamflow lead time using predefine climate indices. A data driven model i.e. Support Vector Machine (SVM) based on the statistical learning theory is used to predict annual streamflow volume 3-year in advance. The SVM model is a learning system that uses a hypothesis space of linear functions in a Kernel induced higher dimensional feature space, and is trained with a learning algorithm from the optimization theory. Annual oceanic-atmospheric indices, comprising of Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), El Niño-Southern Oscillations (ENSO), and a new Sea Surface Temperature (SST) data set of "Hondo" Region for a period of 1906-2005 are used to generate annual streamflow volumes. The SVM model is applied to three gages i.e. Cisco, Green River, and Lees Ferry in the Upper Colorado River Basin in the western United States. Based on the performance measures the model shows very good forecasts, and the forecast are in good agreement with measured streamflow volumes. Previous research has identified NAO and ENSO as main drivers for extending streamflow forecast lead-time in the UCRB. Inclusion of "Hondo Region" SST information further improve the model's forecasting ability. The overall results of this study revealed that the annual streamflow of the UCRB is significantly influenced by

  1. Uses, funding, and availability of continuous streamflow data in Montana

    USGS Publications Warehouse

    Shields, R.R.; White, M.K.

    1984-01-01

    This report documents the results of a study of the uses, funding, and availability of continuous streamflow data collected and published by the U.S. Geological Survey in Montana. Data uses and funding sources are identified for the 218 continuous streamflow gages currently (1984) being operated. These stations are supported by 18 different funding sources at a budget for the 1984 water year of $1,065,000. The streamflow-gaging program in Montana has evolved through the years as Federal, State, and local needs for surface-water data have increased. Continuous streamflow records for periods ranging from less than 1 year to more than 90 years have been collected. This report describes phase 1 of a cost-effectiveness study of the streamflow-gaging program in Montana. Evaluation of the program indicates that numerous agencies use the data for studies involving regional hydrology, hydrologic systems, and planning and design. They also use the data for operations of existing hydroelectric and irrigation dams, forecasting flood and seasonal flows, water-quality monitoring, research studies for fish habitat, and other uses such as recreational management. (USGS)

  2. Accuracy of selected techniques for estimating ice-affected streamflow

    USGS Publications Warehouse

    Walker, John F.

    1991-01-01

    This paper compares the accuracy of selected techniques for estimating streamflow during ice-affected periods. The techniques are classified into two categories - subjective and analytical - depending on the degree of judgment required. Discharge measurements have been made at three streamflow-gauging sites in Iowa during the 1987-88 winter and used to established a baseline streamflow record for each site. Using data based on a simulated six-week field-tip schedule, selected techniques are used to estimate discharge during the ice-affected periods. For the subjective techniques, three hydrographers have independently compiled each record. Three measures of performance are used to compare the estimated streamflow records with the baseline streamflow records: the average discharge for the ice-affected period, and the mean and standard deviation of the daily errors. Based on average ranks for three performance measures and the three sites, the analytical and subjective techniques are essentially comparable. For two of the three sites, Kruskal-Wallis one-way analysis of variance detects significant differences among the three hydrographers for the subjective methods, indicating that the subjective techniques are less consistent than the analytical techniques. The results suggest analytical techniques may be viable tools for estimating discharge during periods of ice effect, and should be developed further and evaluated for sites across the United States.

  3. Seasonal and inter-annual snowmelt patterns in the southern Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Musselman, K. N.; Molotch, N. P.; Margulis, S. A.

    2012-12-01

    In the Sierra Nevada, seasonal snow represents a critical component of California's water resource infrastructure in that it affords reliable water during otherwise arid summers. Complex spatial, seasonal and inter-annual snowmelt patterns determine when and where that meltwater is available. Our knowledge of snowmelt dynamics is typically limited to what we can infer from sparse, point-scale snow measurement stations. Limitations such as these motivate the use of numerical snowmelt models. We evaluate the ability of the Alpine3D model system to represent three years of snow dynamics over an 1800 km2 area of Sequoia National Park. The domain spans a 3600 m elevation gradient and ecosystems ranging from semi-arid grasslands to massive sequoia stands to alpine tundra. The model results were evaluated against data from a multi-scale measurement campaign that included airborne LiDAR, clusters of snow depth sensors, repeated manual snow surveys, and automated SWE stations. Compared to these measurements, Alpine3D consistently performed well in middle elevation conifer forests; compared to LiDAR data, the mean snow depth error in forested regions was < 2%. The model also simulated the snow disappearance date within two days of that measured by regional automated sensors. At upper elevations, however, the model tended to overestimate SWE by 50% to as much as 100% in some areas and the errors were linearly correlated (R2 > 0.80, p<0.01) with the distance of the SWE measurements from the nearest precipitation gauge used to derive the model forcing. The results suggest that Alpine3D is highly accurate during the melt season and that precipitation uncertainty may be a critical limitation on snow model accuracy. Finally, an analysis of seasonal and inter-annual snowmelt patterns highlighted distinct melt differences between lower, middle, and upper elevations. Snowmelt was generally most frequent (70% - 95% of the snow-covered season) at the lower elevations where snow cover

  4. A streamflow routing approach to address temporal change in streamflow response

    NASA Astrophysics Data System (ADS)

    Åkesson, Anna; Wörman, Anders

    2015-04-01

    Temporal variation in the statistical characteristics of the discharge time-series can be noticed in several Swedish catchments where discharge has been measured for a long time period (~100 years). As the trend and its magnitude, can be different in catchments with geographic proximity, the investigated hypothesis is that the temporal change is, at least to some extent, caused by changes in the properties of the stream network. As changing the hydraulic mechanisms within the stream network will have a profound effect on the streamflow response, the primary emphasis in this study is on how stream network structure (distribution and topology of stream reaches) has changed over time. The study is performed by setting up a distributed routing model for the stream network in its present geographic distribution as well as for distribution which has been obtained from historic maps that has been digitized. The travel time distribution through the stream network in the past and present case can thus be used as a descriptor to partly explain how the streamflow response has changed temporally. By use of a distributed routing model based in hydromechanical relationships of energy and momentum, applied to a stream network, velocities are derived at quasi-stationary conditions for a range of discharges, reflecting the prevailing hydraulic mechanisms within stream networks. In the proposed methodology; backwater effects are also included as the downstream boundary conditions (water levels and velocity) are used when determining the slope of the energy line. The results from the distributed routing model are primarily used to interpret the temporal variation in the statistical characteristics of the discharge time-series. Also, the results from the distributed routing modelling can be used as physically based parameters for the streamflow component of a hydrologic model, as the routing model gives rise to a catchment-specific, unambiguous relationship between mean travel time <

  5. Snowmelt infiltration and storage within a karstic environment, Vers Chez le Brandt, Switzerland

    NASA Astrophysics Data System (ADS)

    Meeks, Jessica; Hunkeler, Daniel

    2015-10-01

    Even though karstic aquifers are important freshwater resources and frequently occur in mountainous areas, recharge processes related to snowmelt have received little attention thus far. Given the context of climate change, where alterations to seasonal snow patterns are anticipated, and the often-strong coupling between recharge and discharge in karst aquifers, this research area is of great importance. Therefore, we investigated how snowmelt water transits through the vadose and phreatic zone of a karst aquifer. This was accomplished by evaluating the relationships between meteorological data, soil-water content, vadose zone flow in a cave 53 m below ground and aquifer discharge. Time series data indicate that the quantity and duration of meltwater input at the soil surface influences flow and storage within the soil and epikarst. Prolonged periods of snowmelt promote perched storage in surficial soils and encourage surficial, lateral flow to preferential flow paths. Thus, in karstic watersheds overlain by crystalline loess, a typical pedologic and lithologic pairing in central Europe and parts of North America, soils can serve as the dominant mechanism impeding infiltration and promoting shallow lateral flow. Further, hydrograph analysis of vadose zone flow and aquifer discharge, suggests that storage associated with shallow soils is the dominant source of discharge at time scales of up to several weeks after melt events, while phreatic storage becomes import during prolonged periods without input. Soils can moderate karst aquifer dynamics and play a more governing role on karst aquifer storage and discharge than previously credited. Overall, this signifies that a fundamental understanding of soil structure and distribution is critical when assessing recharge to karstic aquifers, particularly in cold regions.

  6. Early snowmelt events: detection, distribution, and significance in a major sub-arctic watershed

    NASA Astrophysics Data System (ADS)

    Alese Semmens, Kathryn; Ramage, Joan; Bartsch, Annett; Liston, Glen E.

    2013-03-01

    High latitude drainage basins are experiencing higher average temperatures, earlier snowmelt onset in spring, and an increase in rain on snow (ROS) events in winter, trends that climate models project into the future. Snowmelt-dominated basins are most sensitive to winter temperature increases that influence the frequency of ROS events and the timing and duration of snowmelt, resulting in changes to spring runoff. Of specific interest in this study are early melt events that occur in late winter preceding melt onset in the spring. The study focuses on satellite determination and characterization of these early melt events using the Yukon River Basin (Canada/USA) as a test domain. The timing of these events was estimated using data from passive (Advanced Microwave Scanning Radiometer—EOS (AMSR-E)) and active (SeaWinds on Quick Scatterometer (QuikSCAT)) microwave remote sensors, employing detection algorithms for brightness temperature (AMSR-E) and radar backscatter (QuikSCAT). The satellite detected events were validated with ground station meteorological and hydrological data, and the spatial and temporal variability of the events across the entire river basin was characterized. Possible causative factors for the detected events, including ROS, fog, and positive air temperatures, were determined by comparing the timing of the events to parameters from SnowModel and National Centers for Environmental Prediction North American Regional Reanalysis (NARR) outputs, and weather station data. All melt events coincided with above freezing temperatures, while a limited number corresponded to ROS (determined from SnowModel and ground data) and a majority to fog occurrence (determined from NARR). The results underscore the significant influence that warm air intrusions have on melt in some areas and demonstrate the large temporal and spatial variability over years and regions. The study provides a method for melt detection and a baseline from which to assess future change.

  7. Near-Record Early Snowmelt and Signs of Environmental Change in Barrow, Alaska

    NASA Astrophysics Data System (ADS)

    Stanitski, D.; Cox, C.; Sweeney, C.; Divoky, G.; George, C.; Stone, R.

    2015-12-01

    The 2015 spring transition in Barrow, AK, was notable with the second earliest date of snow melt on record (JD148, May 28) and earliest ice free conditions on a local lagoon (JD178, June 27). The 73-year time series from the NOAA Global Monitoring Division's Barrow Observatory (BRW) has shown a trend toward earlier spring snowmelt, reinforced in 2015. Anomalous early snowmelt was also observed at nearby Cooper Island where a colony of sea birds, the Black Guillemot, nests each year once snow disappears. The appearance of "first egg" is well correlated with the date of snowmelt at BRW (Fig. 1), as is the ice-out date at the Isaktoak Lagoon (ISK). In 2015, the first egg was observed on JD159 (June 8), the earliest in the 40-year record (source: Friends of Cooper Island, http://cooperisland.org/). Each day of advance in the melt date at BRW results in an annual net radiation increase at the surface of about 1%. The documented changes can influence biogeochemical cycles, permafrost temperatures, and potentially the release of stored carbon. By mid July 2015, a 1°C increase in soil temperature at 0.5-m depth was measured compared to prior years; therefore, the active layer is expected to be unusually deep by autumn. The anomalous warmth that prevailed during spring 2015 can be attributed, in part, to atmospheric circulation, influenced by two typhoons in the North Pacific and the onset of El Niño. Warming was likely amplified locally as the early melting of snow increased absorption of solar radiation. Key factors influencing the trend toward earlier spring snowmelt will be presented as well as those contributing to the anomalous 2015 spring at BRW (e.g., winter snowfall, cloud cover, advection, local sea ice extent), and the impact early melt had on the 2015 summer surface radiation budget. Analysis of interactions underlying this anomaly will aid in developing strategies for improving predictability of interannual variability of the melt season and long-term change.

  8. Fate of perfluorinated carboxylates and sulfonates during snowmelt within an urban watershed.

    PubMed

    Meyer, Torsten; De Silva, Amila O; Spencer, Christine; Wania, Frank

    2011-10-01

    The transport dynamics of perfluorinated carboxylic acids and sulfonates during snowmelt in the highly urbanized Highland Creek watershed in Toronto, Canada was investigated by analyzing river water, bulk snow, and groundwater, sampled in February and March 2010, by means of liquid chromatography-tandem mass spectrometry. Perfluorohexanoate, perfluorooctanoate, and perfluorooctane sulfonate were dominant in river water, with concentrations of 4.0-14 ng·L(-1), 2.2-7.9 ng·L(-1), and 2.1-6.5 ng·L(-1), respectively. Relatively high levels of perfluorohexanoate may be related to the recent partial replacement in various consumer products of perfluorooctyl substances with shorter-chained perfluorinated compounds (PFCs). Highest PFC concentrations were found within the more urbanized part of the drainage area, suggestive of residential, industrial, and/or traffic-related sources. The riverine flux of PFCs increased during the snowmelt period, but only approximately one-fifth of the increased flux can be attributed to PFCs present in the snowpack, mostly because concentration in snow are generally quite low compared to those in river water. The remainder of the increased flux must be due to the mobilization of PFCs by the high flow conditions prevalent during snowmelt. Run-off behavior was clearly dependent on perfluoroalkyl chain length: Dilution with relatively clean snowmelt water caused a drop in the river water concentrations of short-chain PFCs at high flow during early melting. This prevented an early concentration peak of those water-soluble PFCs within the stream, as could have been expected in response to their early release from a melting snowpack. Instead, concentrations of particle-associated long-chain PFCs in creek water peaked early in the melt, presumably because high flow mobilized contaminated particles from impervious surfaces in the more urbanized areas of the watershed. The ability to enter the subsurface and deeper groundwater aquifers increased

  9. Snowmelt sensitivity to warmer temperatures: a field-validated model analysis, southern Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Musselman, K. N.; Molotch, N. P.; Margulis, S. A.

    2014-12-01

    We present model simulations of climate change impacts on snowmelt processes over a 1600 km2 area in the southern Sierra Nevada, including western Sequoia National Park. The domain spans a 3600 m elevation gradient and ecosystems ranging from semi-arid grasslands to giant sequoia groves to alpine tundra. Three reference years were evaluated: a moderately dry snow season (23% below average SWE), an average snow season (7% above average SWE), and a moderately wet snow season (54% above average SWE). The Alpine3D model was run for the reference years and results were evaluated against data from a multi-scale measurement campaign that included repeated manual snow courses and basin-scale snow surveys, dozens of automated snow depth sensors, and automated SWE stations. Compared to automated measurements, the model represented the date of snow disappearance within two days. Compared to manual measurements, model SWE RMSE values for the average and wet snow seasons were highly correlated (R2=0.89 and R2=0.73) with the distance of SWE measurements from the nearest precipitation gauge used to force the model; no significant correlation was found with elevation. The results suggest that Alpine3D is highly accurate during the melt season and that precipitation uncertainty may critically limit snow model accuracy. The air temperature measured at 19 regional stations for the three reference years was modified by +1°C to +6°C to simulate the impact of warmer temperatures on snowmelt dynamics over the 3600 m elevation gradient. For all years, progressively warmer temperatures caused the seasonal SWE centroid to shift earlier and higher in elevation. At forested middle elevations, 70 - 80% of the present-day snowpack volume is lost in a +2°C scenario; 30 - 40% of that change is a result of precipitation phase shift and the remainder is due to enhanced melt. At all elevations, spring and fall snowpack was most sensitive to warmer temperatures; mid-winter sensitivity was least

  10. Multi-instrument Method to Map Spatial and Temporal Patterns of Snowmelt Infiltration

    NASA Astrophysics Data System (ADS)

    Hyde, K.; Beverly, D.; Thayer, D.; Speckman, H. N.; Parsekian, A.; Kelleners, T.

    2015-12-01

    Mapping spatial patterns of relative soil moisture over time may improve understanding of snowmelt infiltration processes in heterogeneous systems. Conventional soil water measurement methods disturb soil properties and rocky materials generally limit installation of monitoring instruments to shallow depths in mountainous landscapes with snowmelt dominated hydrology. Modifications to existing technology combined with low impact installation methods provide high temporal and spatial resolution of relative soil moisture as well as a temperature profile and water table level. Closely spaced (10cm) electrical resistance pads are combined in a small diameter (2.54 cm) tube with temperature probes each 50cm, a pressure transducer, and a tube to extract groundwater for stable isotope analysis. This vertical probe array (VPA) extends 3.2m and is installed in a small diameter (4 cm) bore using a backpack drill limiting soil disturbance. Two VPAs are installed in the Snowy Range of Wyoming, one in a forested mountainous environment impacted by mortality by insects and disease and the other (limited to resistance pads only) in recently burned sagelands. Each VPA is co-located with meteorological stations. Eddy-covariance, sap flux, electrical resistivity, snowpack survey, and other hillslope eco-hydrology measurements accompany the fully instrumented VPA. Data are sampled and recorded at 5 or 15 minute intervals starting in December 2014. Over the winter both sites exhibit highly variable patterns of relatively dry soils with steady increase in wetness. Abrupt increases in relative wetness occurred with short periods of warming temperatures in Spring. Following a temperature increase in the forested site the relative moisture dramatically increased over a period of several hours at all depths as water level rose 1m within 8 hours. In contrast, following snowmelt relative moisture in the sageland site increased gradually and systematically with depth over a period of two weeks

  11. Isotopic separation of snowmelt runoff during an artificial rain-on-snow event

    NASA Astrophysics Data System (ADS)

    Juras, Roman; Pavlasek, Jirka; Šanda, Martin; Jankovec, Jakub; Linda, Miloslav

    2013-04-01

    Rain-on-snow events are common phenomenon in the climate conditions of central Europe, mainly during the spring snowmelt period. These events can cause serious floods in areas with seasonal snow. The snowpack hit by rain is able to store a fraction of rain water, but runoff caused by additional snowmelt also increases. Assessment of the rainwater ratio contributing to the outflow from the snowpack is therefore critical for discharge modelling. A rainfall simulator and water enriched by deuterium were used for the study of rainwater behaviour during an artificial rain-on-snow event. An area of 1 m2 of the snow sample, which was 1.2 m deep, consisting of ripped coarse-grained snow, was sprayed during the experiment with deuterium enriched water. The outflow from the snowpack was measured and samples of outflow water were collected. The isotopic content of deuterium was further analyzed from these samples by means of laser spectroscopy for the purpose of hydrograph separation. The concentration of deuterium in snow before and after the experiment was also investigated. The deuterium enriched water above the natural concentration of deuterium in snowpack was detected in the outflow in 7th minute from start of spraying, but the significant increase of deuterium concentration in outflow was observed in 19th minute. The isotopic hydrograph separation estimated, that deuterium enriched rainwater became the major part (> 50% volumetric) of the outflow in 28th minute. The culmination of the outflow (1.23 l min-1) as well as deuterium enriched rainwater fraction (63.5%) in it occurred in 63th minute, i.e. right after the end of spraying. In total, 72.7 l of deuterium enriched water was sprayed on the snowpack in 62 minutes. Total volume of outflow (after 12.3 hours) water was 97.4 l, which contained 48.3 l of deuterium enriched water (i.e. 49.6 %) and 49.1 l (50.4 %) of the melted snowpack. The volume of 24.4 l of deuterium enriched spray-water was stored in the snowpack. The

  12. Diverging sensitivity of soil water stress to changing snowmelt timing in the Western U.S.

    NASA Astrophysics Data System (ADS)

    Harpold, Adrian A.

    2016-06-01

    Altered snowpack regimes from regional warming threaten mountain ecosystems with greater water stress and increased likelihood of vegetation disturbance. The sensitivity of vegetation to changing snowpack conditions is strongly mediated by soil water storage, yet a framework to identify areas sensitive to changing snowpack regimes is lacking. In this study we ask two questions: (1) How will changing snowmelt alter the duration of soil water stress and length of the soil-mediated growing season (shortened to water stress and growing season, respectively)? and (2) What site characteristics increase the sensitivity of water stress and growing season duration to changes in snowmelt? We compiled soil moisture at 5, 20 and 50 cm depths from 62 SNOTEL sites with > 5 years of records and detailed soil properties. Soil water stress was estimated based on measured wilting point water content. The day of snow disappearance consistently explained the greatest variability in water stress across all site-years and within individual sites, while summer precipitation explained the most variability in growing season length. On average, a one day earlier snow disappearance resulted in 0.62 days greater water stress and 36 of 62 sites had significant relationships between snow disappearance and water stress. Despite earlier snow disappearance leading to greater water stress at nearly all sites, earlier snow disappearance led to both significant increases (4 of 62) and decreases (5 of 62) in growing season length. Satellite derived vegetation greenness confirmed site-dependent changes could both increase and reduce maximum annual vegetation greenness with earlier snow disappearance. A simple soil moisture model demonstrated the potential for diverging growing season length with earlier snow disappearance was more likely in areas with finer soil texture, greater rooting depth, greater potential evapotranspiration, and greater precipitation. More work is needed to understand the role of

  13. Evaluation of Maximum Likelihood Ensemble Filter for Real-Time Assimilation of Streamflow Data in Operational Streamflow Forecasting

    NASA Astrophysics Data System (ADS)

    Rafieei Nasab, A.; Seo, D.; LEE, H.; Kim, S.

    2012-12-01

    Various data assimilation (DA) methods have been used and are being explored for use in operational streamflow forecasting. For ensemble forecasting, Ensemble Kalman filter (EnKF) is an appealing candidate for familiarity and relative simplicity. EnKF, however, is optimal only if the observation equation is linear. As such, without an iterative approach, EnKF may not be appropriate for assimilating streamflow data into soil moisture accounting models. Maximum likelihood ensemble filter (MLEF), on the other hand, is not subject to the above limitation. Also, as an ensemble extension of variational assimilation (VAR), MLEF offers a strong connection with the traditional single-valued forecast process through the control, or the maximum likelihood, solution. In this work, we apply MLEF to the Sacramento (SAC) soil moisture accounting model and unit hydrograph (UH) for assimilation of streamflow, precipitation and potential evaporation (PE) data. A comparison between VAR and the control run of MLEF is made to verify the performance of MLEF, including that of the gradient approximation which does not require adjoint code. Sensitivity analysis is then performed to assess the performance of MLEF with respect to the ensemble size, the number of streamflow observations assimilated in each cycle, the statistical parameters for observation errors in streamflow, precipitation and PE, and for model error associated with the runoff from SAC. We also identify the science issues and challenges toward operationalization.

  14. Streamflow Characteristics of Streams in the Helmand Basin, Afghanistan

    USGS Publications Warehouse

    Williams-Sether, Tara

    2008-01-01

    Statistical summaries of streamflow data for all historical streamflow-gaging stations for the Helmand Basin upstream from the Sistan Wetlands are presented in this report. The summaries for each streamflow-gaging station include (1) manuscript (station description), (2) graph of the annual mean discharge for the period of record, (3) statistics of monthly and annual mean discharges, (4) graph of the annual flow duration, (5) monthly and annual flow duration, (6) probability of occurrence of annual high discharges, (7) probability of occurrence of annual low discharges, (8) probability of occurrence of seasonal low discharges, (9) annual peak discharge and corresponding gage height for the period of record, and (10) monthly and annual mean discharges for the period of record.

  15. Drought and climatic change impact on streamflow in small watersheds.

    PubMed

    Tigkas, Dimitris; Vangelis, Harris; Tsakiris, George

    2012-12-01

    The paper presents a comprehensive, thought simple, methodology, for forecasting the annual hydrological drought, based on meteorological drought indications available early during the hydrological year. The meteorological drought of 3, 6 and 9 months is estimated using the reconnaissance drought index (RDI), whereas the annual hydrological drought is represented by the streamflow drought index (SDI). Regression equations are derived between RDI and SDI, forecasting the level of hydrological drought for the entire year in real time. Further, using a wide range of scenarios representing possible climatic changes and drought events of varying severity, nomographs are devised for estimating the annual streamflow change. The Medbasin rainfall-runoff model is used to link meteorological data to streamflow. The later approach can be useful for developing preparedness plans to combat the consequences of drought and climate change. As a case study, the area of N. Peloponnese (Greece) was selected, incorporating several small river basins. PMID:22963988

  16. Functional streamflow disaggregation - modern variations on a classical theme

    NASA Astrophysics Data System (ADS)

    Carl, P.; Behrendt, H.

    2009-04-01

    Conceptual foundation, algorithmic solution, and independent evaluation of exemplary applications are given of the recently introduced "functional streamflow disaggregation" (FSD) technique (WRR, 2008). This is an algorithmic construct of blind, largely non-probabilistic, uncalibrated, 'minimalistic' runoff analysis. It starts with a first guess using a variant of singular-system analysis (SSA) and runs through a hierarchy of lower streamflow envelopes as obtained by means of iterative cubic spline interpolation (CSI). A lower bound is preset by a sort of minimal convolution. In doing so, empirical streamflow components are separated, also suggesting comparison with structured runoff as obtained from hydrologic modelling. Assignment to classical overland, vadose zone, and base flows, i.e., to conceptual entities of the parallel-flow framework, is discussed for daily runoff from three headwater catchments of German and Austrian highlands environments. The method has recourse to the regular time series contents, leaving multifractal analyses as proper means of further independent evaluation.

  17. LARGE-SCALE PATTERNS OF STREAMFLOW DISTURBANCE AND FISH COMMUNITIES IN UPPER MISSOURI RIVER BASIN, USA

    EPA Science Inventory

    Patterns of streamflow variability are likely to be a major organizing feature of the habitat template for stream fishes. Functional organization of stream communities has been linked to streamflow, especially to patterns of flow variability that describe the physical disturbanc...

  18. Statistical Analysis of Streamflow Trends in Slovenia

    NASA Astrophysics Data System (ADS)

    Jurko, M.; Kobold, M.; Mikoš, M.

    2009-04-01

    According to climate change, trends of river discharges were analyzed showing the hydrological change and future projections of hydrological behaviour in Slovenia. In last years droughts and floods are becoming more and more frequent. In the statistical analysis of streamflow trends of Slovenian rivers, available data on the low, mean and high discharges were examined using mean daily discharges and the Hydrospect software, which was developed under the auspices of WMO for detecting changes in hydrological data (Kundzewicz and Robson, 2000). The Mann-Kendall test was applied for the estimation of trends in the river flow index series. Trend analysis requires long records of observation to distinguish climate change-induced trends from climate variability. The problems of missing values, seasonal and other short-term fluctuations or anthropogenic impacts and lack of homogeneity of data due to the changes in instruments and observation techniques are frequently present in existing hydrological data sets. Therefore the analysis was carried out for 77 water gauging stations representatively distributed across Slovenia with sufficiently long and reliable continuous data sets. The average length of the data sets from the selected water gauging stations is about 50 years. Different indices were used to assess the temporal variation of discharges: annual mean daily discharge, annual maximum daily discharge, two magnitude and frequency series by peak-over-threshold (POT) approach (POT1 and POT3), and two low flow indices describing the different duration of low flows (7 and 30 days). The clustering method was used to classify the results of trends into groups. The assumption of a general decrease of water quantities in Slovenian rivers was confirmed. The annual mean daily discharges of the analyzed water gauging stations show a significant negative trend for the majority of the stations. Similar results with lower statistical significance show annual minimum 7-day and 30

  19. Evaluation of streamflow estimates for the Rovuma River

    NASA Astrophysics Data System (ADS)

    Minihane, M. R.

    Reliable estimates of historic streamflow are important when estimating future flows and water resources availability based on factors such as climate change, population growth, and changes in land use or land cover. Many regions across the globe have limited streamflow observations. Additional information about streamflow in these basins is critical to water resources planning and economic development strategies. In southeastern Africa, the remote Rovuma River lies on the border between Mozambique and Tanzania. There are limited historic measurements in the main tributary, the Lugenda River, and no publicly available observations from recent years. Improved knowledge of the water resources availability and seasonal and annual variability of this river will enhance transboundary river basin management discussions. A combination of methods, including index-gauge methods and a macro-scale hydrological model are used to estimate historic streamflow conditions in the Rovuma River. These methods incorporate data from remote sensing, gridded global soil data, a composite runoff dataset, and in situ observations. The hydrological model was tested in a nearby gauged basin yielding a Nash-Sutcliffe efficiency ratio of 0.8, an efficiency ratio based on mean historical streamflow by month of 0.6, an efficiency ratio based on inverse flows (sensitive to low flows) of 0.9, and a coefficient of determination equal to 0.99. In the Rovuma River, the mean and standard deviation of the index gauge-estimated mean monthly flows agree with streamflow estimates using the Variable Infiltration Capacity (VIC) hydrologic model with a 0.25 decimal degree spatial resolution. A closer look at precipitation records suggests that the model results provide a more accurate historic flow record than the index gauge methods due to small-scale precipitation events. Model inputs and results are evaluated by leveraging available regional in situ data in comparison to remote sensing data input data

  20. Separating streamflow components to reveal nutrient flowpaths: Toenepi Stream

    NASA Astrophysics Data System (ADS)

    Stewart, Michael

    2015-04-01

    Separating streamflow into its components is valuable for understanding the sources and flowpaths of water and solutes in catchments, in particular nutrient flowpaths. Tracers give an objective basis for hydrograph separations, but such tracer data is usually quite limited in time even if available for a catchment. A new separation method (the bump and rise method or BRM, Stewart 2014) gives a filter that can be calibrated by fitting to tracer separations and then applied to the whole streamflow record. Or if no tracer data is available, can be calibrated more approximately by fitting to the recession hydrograph. The value of the procedure is illustrated by applying it to Toenepi Stream, which drains a lowland dairy farming catchment of 15.1 km2 in Waikato, New Zealand. Tracer (chemical and tritium) measurements show that streamflow is made up of three major end-members or components in varying proportions: high-nitrate quickflow, young nitrate-bearing fast groundwater from a shallow aquifer, and old nitrate-free slow groundwater from a deeper aquifer. Hydrographs of these three components were determined by applying the BRM filter twice, once to the streamflow and then again to the baseflow. The results show that (1) quickflow responds rapidly to rainfall but contributes only a minor part of the stream peak, (2) fast groundwater also responds rapidly and contributes most of the stream peak, and (3) slow groundwater shows little immediate response but begins a very gradual rise in contribution after rainfall. By assuming constant nitrate concentrations for the three components, the continuous variation of nitrate in the streamflow was calculated and showed good agreement with spot streamflow measurements. Nitrate concentrations reached very low levels during very low flows when the stream was dominated by the slow groundwater, and increased with flow as the proportions of quickflow and fast groundwater increased. The BRM method was flexible enough to enable

  1. An environmental streamflow assessment for the Santiam River basin, Oregon

    USGS Publications Warehouse

    Risley, John C.; Wallick, J. Rose; Mangano, Joseph F.; Jones, Krista L.

    2012-01-01

    The Santiam River is a tributary of the Willamette River in northwestern Oregon and drains an area of 1,810 square miles. The U.S. Army Corps of Engineers (USACE) operates four dams in the basin, which are used primarily for flood control, hydropower production, recreation, and water-quality improvement. The Detroit and Big Cliff Dams were constructed in 1953 on the North Santiam River. The Green Peter and Foster Dams were completed in 1967 on the South Santiam River. The impacts of the structures have included a decrease in the frequency and magnitude of floods and an increase in low flows. For three North Santiam River reaches, the median of annual 1-day maximum streamflows decreased 42–50 percent because of regulated streamflow conditions. Likewise, for three reaches in the South Santiam River basin, the median of annual 1-day maximum streamflows decreased 39–52 percent because of regulation. In contrast to their effect on high flows, the dams increased low flows. The median of annual 7-day minimum flows in six of the seven study reaches increased under regulated streamflow conditions between 60 and 334 percent. On a seasonal basis, median monthly streamflows decreased from February to May and increased from September to January in all the reaches. However, the magnitude of these impacts usually decreased farther downstream from dams because of cumulative inflow from unregulated tributaries and groundwater entering the North, South, and main-stem Santiam Rivers below the dams. A Wilcox rank-sum test of monthly precipitation data from Salem, Oregon, and Waterloo, Oregon, found no significant difference between the pre-and post-dam periods, which suggests that the construction and operation of the dams since the 1950s and 1960s are a primary cause of alterations to the Santiam River basin streamflow regime. In addition to the streamflow analysis, this report provides a geomorphic characterization of the Santiam River basin and the associated conceptual

  2. Climatic change projections for winter streamflow in Guadalquivir river

    NASA Astrophysics Data System (ADS)

    Jesús Esteban Parra, María; Hidalgo Muñoz, José Manuel; García-Valdecasas-Ojeda, Matilde; Raquel Gámiz Fortis, Sonia; Castro Díez, Yolanda

    2015-04-01

    In this work we have obtained climate change projections for winter streamflow of the Guadalquivir River in the period 2071-2100 using the Principal Component Regression (PCR) method. The streamflow data base used has been provided by the Center for Studies and Experimentation of Public Works, CEDEX. Series from gauging stations and reservoirs with less than 10% of missing data (filled by regression with well correlated neighboring stations) have been considered. The homogeneity of these series has been evaluated through the Pettit test and degree of human alteration by the Common Area Index. The application of these criteria led to the selection of 13 streamflow time series homogeneously distributed over the basin, covering the period 1952-2011. For this streamflow data, winter seasonal values were obtained by averaging the monthly values from January to March. The PCR method has been applied using the Principal Components of the mean anomalies of sea level pressure (SLP) in winter (December to February averaged) as predictors of streamflow for the development of a downscaled statistical model. The SLP database is the NCEP reanalysis covering the North Atlantic region, and the calibration and validation periods used for fitting and evaluating the ability of the model are 1952-1992 and 1993-2011, respectively. In general, using four Principal Components, regression models are able to explain up to 70% of the variance of the streamflow data. Finally, the statistical model obtained for the observational data was applied to the SLP data for the period 2071-2100, using the outputs of different GCMs of the CMIP5 under the RPC8.5 scenario. The results found for the end of the century show no significant changes or moderate decrease in the streamflow of this river for most GCMs in winter, but for some of them the decrease is very strong. Keywords: Statistical downscaling, streamflow, Guadalquivir River, climate change. ACKNOWLEDGEMENTS This work has been financed by the

  3. Streamflow variability in the United States: 1931-1978.

    USGS Publications Warehouse

    Lins, H.F.

    1985-01-01

    Systematic modes of spatial and temporal variation in a 48-year record of streamflow are defined using principal components. The components were calculated from a matrix of annual streamflow departures for 106 grid cells covering the United States in the years 1931-78. Five statistically significant components are found to account for more than 56% of the total variance. A varimax orthogonal rotation of the original components describes regional anomaly cores located in the middle Mississippi Valley, Pacific Northwest, Far West, Northeast, and northern Great Plains. -from Author

  4. A proposed streamflow-data program in Alaska

    USGS Publications Warehouse

    Childers, J.M.

    1970-01-01

    The streamflow-data program in Alaska was analyzed to design a better data network. The analysis included (1) definition of the goals of the streamflow-data program, (2) evaluation of the available data to see which goals have already been achieved, and (3) consideration and recommendation of future programs to achieve the goals that have not been met. It was found that few of the goals have been met. Many new gaging stations are proposed to provide data to reach remaining unmet goals. Also, other kinds of data collection are proposed to complement the gaging-station data to attain the goals.

  5. A New Method to Evaluate Streamflow Recovery After a Drought

    NASA Astrophysics Data System (ADS)

    Kienzle, S. W.

    2004-12-01

    Under conditions of environmental change, occurrences of drought are expected to increase in number and severity. A river basin does not behave linearly to precipitation, and many drought indices, such as the Palmer Drought Severity Index (Palmer, 1965), are based on meteorological conditions, since they were developed for agricultural purposes rather than hydrological behavior of a river basin. A new method is presented to answer the question "When does the streamflow recover to normal conditions after a drought?", a question raised by many water managers who rely on adequate streamflow and reservoir levels, particularly municipalities, industry, power stations, and irrigation districts. The recession index is an indicator for the overall water basin conditions, and integrates all streamflow generating conditions, including the status of groundwater, wetlands, and basin wetness (or antecedent watershed conditions). The method is based on recession analysis of daily streamflow utilizing the RECESS program (Rutledge, 2004). The recession index K is calculated for all streamflow available records. Analysis of recession indices of streamflow in the Battle River Basin, a prairie watershed in central Alberta, Canada, was carried out using a minimum length of recession curves of 5 days. The analysis reveals drought years have associated low median annual K values, measured in days per log cycle, while normal to wet years have high median annual K values. The suggested method can be used to evaluate the overall status of a river basin in terms of runoff conditions by relating the latest measured recession index to the historical record. This gives an indication if, in terms of streamflow response, a river basin is still in a drought, in a phase of recovery, or fully recovered. Water managers can then predict water availability for the coming months. References: Palmer, W. C, 1965: Meteorological Drought. Res. Paper No.45, 58pp., Dept. of Commerce, Washington, D

  6. National Estimates of the Recreational Value of Streamflow

    NASA Astrophysics Data System (ADS)

    Hansen, Leroy T.; Hallam, Arne

    1991-02-01

    This paper presents one practical method of valuing the recreational fishing benefits generated by a unit of water as it moves downstream. A cross-sectional analysis is employed to estimate the change in individuals' fishing behavior due to a change in availability of fishery resources. A proxy for the availability of stream fishery resources is derived from the link between changes in streamflow consumption to changes in the quality of fishing downstream. The results show that marginal increases in streamflow can generate recreational benefits that exceed the marginal value of water in agriculture in some regions of the country.

  7. Simulation of streamflow and estimation of streamflow constituent loads in the San Antonio River watershed, Bexar County, Texas, 1997-2001

    USGS Publications Warehouse

    Ockerman, Darwin J.; McNamara, Kenna C.

    2003-01-01

    The U.S. Geological Survey developed watershed models (Hydrological Simulation Program?FORTRAN) to simulate streamflow and estimate streamflow constituent loads from five basins that compose the San Antonio River watershed in Bexar County, Texas. Rainfall and streamflow data collected during 1997?2001 were used to calibrate and test the model. The model was configured so that runoff from various land uses and discharges from other sources (such as wastewater recycling facilities) could be accounted for to indicate sources of streamflow. Simulated streamflow volumes were used with land-use-specific, water-quality data to compute streamflow loads of selected constituents from the various streamflow sources. Model simulations for 1997?2001 indicate that inflow from the upper Medina River (originating outside Bexar County) represents about 22 percent of total streamflow. Recycled wastewater discharges account for about 20 percent and base flow (ground-water inflow to streams) about 18 percent. Storm runoff from various land uses represents about 33 percent. Estimates of sources of streamflow constituent loads indicate recycled wastewater as the largest source of dissolved solids and nitrate plus nitrite nitrogen (about 38 and 66 percent, respectively, of the total loads) during 1997?2001. Stormwater runoff from urban land produced about 49 percent of the 1997?2001 total suspended solids load. Stormwater runoff from residential and commercial land (about 23 percent of the land area) produced about 70 percent of the total lead streamflow load during 1997?2001.

  8. Summary of Percentages of Zero Daily Mean Streamflow for 712 U.S. Geological Survey Streamflow-Gaging Stations in Texas Through 2003

    USGS Publications Warehouse

    Asquith, William H.; Vrabel, Joseph; Roussel, Meghan C.

    2007-01-01

    Analysts and managers of surface-water resources might have interest in the zero-flow potential for U.S.Geological Survey (USGS) streamflow-gaging stations in Texas. The USGS, in cooperation with the Texas Commission on Environmental Quality, initiated a data and reporting process to generate summaries of percentages of zero daily mean streamflow for 712 USGS streamflow-gaging stations in Texas. A summary of the percentages of zero daily mean streamflow for most active and inactive, continuous-record gaging stations in Texas provides valuable information by conveying the historical perspective for zero-flow potential for the watershed. The summaries of percentages of zero daily mean streamflow for each station are graphically depicted using two thematic perspectives: annual and monthly. The annual perspective consists of graphs of annual percentages of zero streamflow by year with the addition of lines depicting the mean and median annual percentage of zero streamflow. Monotonic trends in the percentages of zero streamflow also are identified using Kendall's T. The monthly perspective consists of graphs of the percentage of zero streamflow by month with lines added to indicate the mean and median monthly percentage of zero streamflow. One or more summaries could be used in a watershed, river basin, or other regional context by analysts and managers of surface-water resources to guide scientific, regulatory, or other inquiries of zero-flow or other low-flow conditions in Texas.

  9. MODFLOW-LGR-Modifications to the streamflow-routing package (SFR2) to route streamflow through locally refined grids

    USGS Publications Warehouse

    Mehl, Steffen W.; Hill, Mary C.

    2011-01-01

    This report documents modifications to the Streamflow-Routing Package (SFR2) to route streamflow through grids constructed using the multiple-refined-areas capability of shared node Local Grid Refinement (LGR) of MODFLOW-2005. MODFLOW-2005 is the U.S. Geological Survey modular, three-dimensional, finite-difference groundwater-flow model. LGR provides the capability to simulate groundwater flow by using one or more block-shaped, higher resolution local grids (child model) within a coarser grid (parent model). LGR accomplishes this by iteratively coupling separate MODFLOW-2005 models such that heads and fluxes are balanced across the shared interfacing boundaries. Compatibility with SFR2 allows for streamflow routing across grids. LGR can be used in two- and three-dimensional, steady-state and transient simulations and for simulations of confined and unconfined groundwater systems.

  10. Map correlation method: Selection of a reference streamgage to estimate daily streamflow at ungaged catchments.

    USGS Publications Warehouse

    Archfield, Stacey A.; Vogel, Richard M.

    2010-01-01

    Daily streamflow time series are critical to a very broad range of hydrologic problems. Whereas daily streamflow time series are readily obtained from gaged catchments, streamflow information is commonly needed at catchments for which no measured streamflow information exists. At ungaged catchments, methods to estimate daily streamflow time series typically require the use of a reference streamgage, which transfers properties of the streamflow time series at a reference streamgage to the ungaged catchment. Therefore, the selection of a reference streamgage is one of the central challenges associated with estimation of daily streamflow at ungaged basins. The reference streamgage is typically selected by choosing the nearest streamgage; however, this paper shows that selection of the nearest streamgage does not provide a consistent selection criterion. We introduce a new method, termed the map-correlation method, which selects the reference streamgage whose daily streamflows are most correlated with an ungaged catchment. When applied to the estimation of daily streamflow at 28 streamgages across southern New England, daily streamflows estimated by a reference streamgage selected using the map-correlation method generally provides improved estimates of daily streamflow time series over streamflows estimated by the selection and use of the nearest streamgage. The map correlation method could have potential for many other applications including identifying redundancy and uniqueness in a streamgage network, calibration of rainfall runoff models at ungaged sites, as well as for use in catchment classification.

  11. Tracing sources of nitrate in snowmelt runoff using a high-resolution isotopic technique

    USGS Publications Warehouse

    Ohte, N.; Sebestyen, S.D.; Shanley, J.B.; Doctor, D.H.; Kendall, C.; Wankel, Scott D.; Boyer, E.W.

    2004-01-01

    The denitrifier method to determine the dual isotopic composition (??15N and ??18O) of nitrate is well suited for studies of nitrogen contributions to streams during runoff events. This method requires only 70 nmol of NO3- and enables high throughput of samples. We studied nitrate sources to a headwater stream during snowmelt by generating a high-temporal resolution dataset at the Sleepers River Research Watershed in Vermont, USA. In the earliest phase of runoff, stream NO3- concentrations were highest and stream discharge, NO3- concentrations, and ??18O of NO 3- generally tracked one another during diurnal melting. The isotopic composition of stream NO3- varied in-between atmospheric and groundwater NO 3- end members indicating a direct contribution of atmospherically-derived NO3- from the snow pack to the stream. During the middle to late phases of snowmelt, the source shifted toward soil NO3- entering the stream via shallow subsurface flow paths. Copyright 2004 by the American Geophysical Union.

  12. Temperature, snowmelt, and the onset of spring season landslides in the central Rocky Mountains

    USGS Publications Warehouse

    Chleborad, Alan F.

    1997-01-01

    Snow meltwater (snowmelt) that seeps into the subsurface is a major factor contributing to the development of landslides during the spring in mountainous areas of the Rocky Mountain region. An examination of historical temperature data in relation to spring season landslide occurrences reveals an association between the landslide events and intervals of rising temperatures that accelerate the production of snow meltwater. Historical climatic data recorded at local weather stations located near the landslide sites are used to show the association and to identify a temperature threshold that may be useful for forecasting the onset of spring season landslides. Historical daily temperature maximums and minimums for unmonitored landslide sites are estimated by applying an elevation correction factor to historical temperature data from nearby weather stations. The proposed temperature threshold (a 6-day moving average of daily maximum temperature of 58? F) is defined by the number and temporal distribution of snowmelt related landslide events. The results of the study suggest that real-time temperature data recorded at weather stations throughout the Rocky Mountain region is potentially a valuable source of information that may be useful for forecasting the onset of spring season landslides.

  13. A simple numerical method for snowmelt simulation based on the equation of heat energy.

    PubMed

    Stojković, Milan; Jaćimović, Nenad

    2016-01-01

    This paper presents one-dimensional numerical model for snowmelt/accumulation simulations, based on the equation of heat energy. It is assumed that the snow column is homogeneous at the current time step; however, its characteristics such as snow density and thermal conductivity are treated as functions of time. The equation of heat energy for snow column is solved using the implicit finite difference method. The incoming energy at the snow surface includes the following parts: conduction, convection, radiation and the raindrop energy. Along with the snow melting process, the model includes a model for snow accumulation. The Euler method for the numerical integration of the balance equation is utilized in the proposed model. The model applicability is demonstrated at the meteorological station Zlatibor, located in the western region of Serbia at 1,028 meters above sea level (m.a.s.l.) Simulation results of snowmelt/accumulation suggest that the proposed model achieved better agreement with observed data in comparison with the temperature index method. The proposed method may be utilized as part of a deterministic hydrological model in order to improve short and long term predictions of possible flood events. PMID:27054726

  14. Influence of El Nino and ITCZ on Brazilian River Streamflows

    NASA Astrophysics Data System (ADS)

    Lopes, A.; Dracup, J. A.

    2010-12-01

    This study analyzes effects of climatic phenomena El Nino and ITCZ latitudinal movements on streamflow patterns in major Brazilian river basins: Amazon (north), Araguaia-Tocantins (central-north), Parana (central-south) and Sao Francisco (central-northeast). Multiple correlation between annual streamflows and the NINO 3.4 and North Tropical Atlantic SST indexes (NTA) were analyzed for each river basin using different annual periods in order to account for the delay in streamflow response. The data consists of unimpaired river discharge time series at key points (from the Brazilian National Water Agency (ANA)); normalized yearly averaged NINO3.4 index characterizing El Nino (from NOAA); and NTA index (from NOAA), as a surrogate of the latitudinal movement of the ITCZ, since it is correlated to the Atlantic SST gradient. As a result, each river basin showed a different response. At the Amazon river basin, almost all dry years occurred when NINO3.4 was above average (El Nino years). Moreover, in almost every year when NINO3.4 was below average (La Nina) the streamflows were above average. Thus, it seems that La Nina have strong effects in floods in Amazon river. Moreover, El Nino events seem to be a necessary, but not sufficient condition for low streamflows at Amazon river. A weaker relationship was found for Xingu river basin, since it is probably affected by cold fronts from the south. As the location of river basins changes towards the south, the effect of El Nino events gets weaker as for Araguaia-Tocantins and Sao Francisco river basins. At the Parana river basin, the relationship is reversed. Almost all extreme wet years occurred during El Nino years. The correlation between streamflows and the NTA indexes were very weak for all river basins except for the Amazon. When the NTA anomaly is negative, wet years occurs, since the ITCZ moves southwards and stays longer at that position, increasing rainfall over the Amazon and Northeast of Brazil. In contrast, almost

  15. Characteristics and Classification of Least Altered Streamflows in Massachusetts

    USGS Publications Warehouse

    Armstrong, David S.; Parker, Gene W.; Richards, Todd A.

    2008-01-01

    Streamflow records from 85 streamflow-gaging stations at which streamflows were considered to be least altered were used to characterize natural streamflows within southern New England. Period-of-record streamflow data were used to determine annual hydrographs of median monthly flows. The shapes and magnitudes of annual hydrographs of median monthly flows, normalized by drainage area, differed among stations in different geographic areas of southern New England. These differences were gradational across southern New England and were attributed to differences in basin and climate characteristics. Period-of-record streamflow data were also used to analyze the statistical properties of daily streamflows at 61 stations across southern New England by using L-moment ratios. An L-moment ratio diagram of L-skewness and L-kurtosis showed a continuous gradation in these properties between stations and indicated differences between base-flow dominated and runoff-dominated rivers. Streamflow records from a concurrent period (1960-2004) for 61 stations were used in a multivariate statistical analysis to develop a hydrologic classification of rivers in southern New England. Missing records from 46 of these stations were extended by using a Maintenance of Variation Extension technique. The concurrent-period streamflows were used in the Indicators of Hydrologic Alteration and Hydrologic Index Tool programs to determine 224 hydrologic indices for the 61 stations. Principal-components analysis (PCA) was used to reduce the number of hydrologic indices to 20 that provided nonredundant information. The PCA also indicated that the major patterns of variability in the dataset are related to differences in flow variability and low-flow magnitude among the stations. Hierarchical cluster analysis was used to classify stations into groups with similar hydrologic properties. The cluster analysis classified rivers in southern New England into two broad groups: (1) base-flow dominated rivers

  16. Quantifying depression storage of snowmelt runoff over frozen ground using aerial photography and digital elevation model

    NASA Astrophysics Data System (ADS)

    Hayashi, M.; Donovan, K.; Sjogren, D.

    2004-05-01

    The northern prairie region of North America is characterized by undulating terrains with very low regional gradient, underlain by clay-rich glacial tills. The soils derived from clay-rich tills have very low permeability when they are frozen. As a result a large amount of snowmelt runoff is generated over frozen ground. Numerous depressions on the undulating terrains trap snowmelt water and focus the infiltration flux under the depressions. Therefore, the depressions have important hydrologic functions regarding runoff retention and groundwater recharge. Previous studies have investigated the storage of snowmelt runoff and subsequent infiltration at a scale of each depression (102-103 m2). However, to understand the roles of depressions in regional hydrology, depression storage needs to be evaluated at a much larger scale. Our ultimate goal is to quantify depression storage at the scale of watersheds (102-103km 2) and represent it properly in a large-scale hydrologic model. As the first step towards this goal, we quantified depression storage at 1-km2 scale using infrared (IR) aerial photographs and digital elevation model combined with the measurement of water depth in depressions. Two parcels of land were selected for the study in the watershed of West Nose Creek, located immediately north of Calgary, Alberta, Canada. Each site contained a subsection of native prairie grass and cultivated field. Snow surveys were conducted at each site to estimate the average snow water equivalent (SWE) on the ground prior to melt. SWE ranged between 26 mm and 39 mm. Water depth was measured in 111 depressions when they were filled up to the peak level, and IR photographs were taken simultaneously at a scale of 1:10,000. The soil was frozen to a depth of 1 m or greater as indicated by several thermocouple arrays installed at the site. Detailed elevation survey was conducted in summer using a total station and differential global positioning system for 10 selected depressions to

  17. A proposed streamflow-data program for Wisconsin

    USGS Publications Warehouse

    Campbell, Roy E.; Dreher, Frederick C.

    1970-01-01

    The historical data acquired and the new data to be collected form the basis for analytical and interpretive reports. Recommendations were made as to expanding or initiating such studies. Streamflow data collection should be a continuing effort, reoriented as necessary to meet the changing needs.

  18. A comparison of four streamflow record extension techniques.

    USGS Publications Warehouse

    Hirsch, R.M.

    1982-01-01

    One approach to developing time series of streamflow, which may be used for simulation and optimization studies of water resources development activities, is to extend an existing gage record in time by exploiting the interstation correlation between the station of interest and some nearby (long-term) base station. Four methods of extension are described, and their properties are explored. -from Author

  19. Seasonal Streamflow Reconstructions of the Choctawhatchee River (AL-USA)

    NASA Astrophysics Data System (ADS)

    Tootle, G. A.; Therrell, M.; Moat, T.; Meko, M.

    2015-12-01

    Tree ring samples were collected from Bald Cypress (Taxodium distichum) species in watersheds adjacent to the Choctawhatchee River (Alabama and Florida - USA). These samples were collected to update an existing tree ring proxy that was developed in the late 1980's and early 1990's (Stahle and Cleaveland, 1992, IGBP PAGES/World Data Center for Paleoclimatology Data Contribution # FL001, Choctawhatchee River. NOAA/NCDC Paleoclimatology Program, Boulder, Colorado, USA). The motivation for updating the tree ring proxy was to determine if recent droughts identified in historic unimpaired Choctawhatchee River streamflow records were reflected in Bald Cypress tree ring growth. Historic streamflow from 1934 to 2013 was obtained for the USGS station at Newton, Alabama and one, five and ten-year droughts were identified and ranked. Many of the most severe droughts were identified in recent (~2000 to present) records (see Figure). Combining the new tree ring proxy with other regional proxies, seasonal streamflow was reconstructed for the Choctawhatchee River Newton, Alabama gage. The reconstructed streamflow allows water managers and planners to observe past wet and dry periods that may exceed magnitude, duration and/or severity of wet and dry periods in observed records.

  20. A New Integrated Neural Network Architecture for Streamflow Forecasting

    NASA Astrophysics Data System (ADS)

    Teegavarapu, R. S.

    2005-12-01

    Streamflow time series often provide valuable insights into the underlying physical processes that govern response of any watershed. Patterns derived from time series based on repeated structures within these series can be beneficial for developing new or improved data-driven forecasting models. Data-driven models, artificial neural networks (ANN), are developed in the current study for streamflow prediction using input structures that are classified into geometrically similar patterns. The number of patterns that are identified in a series depends on the lagged values of streamflows used in the input structures of the ANN model. A new modular and integrated ANN architecture that combines several ANN models, referred to as pattern-classified neural network (PCNN), is proposed, developed and investigated in this study. The ANN models are used for one step-ahead prediction of streamflows for Reed Creek and Little River, Virginia. Results obtained from this study suggest that the use of these patterns in the process of training has improved the performance of the neural networks in prediction. The improved performance of the ANN models can be attributed to prior classification of data, which in a way has complimented and enhanced the already existing classification abilities of the neural networks. The PCNN architecture also provides the benefit of better generalization of a data-driven model by developing several independent models instead of one global data-driven prediction model for the entire data.

  1. HYDRO-CLIMATIC DATA NETWORK (HCDN): STREAMFLOW, 1874-1988

    EPA Science Inventory

    The U.S. Geological Survey (USGS) Global Change Hydrology Program has developed a streamflow data set, which is specifically suitable for the study of surface-water conditions throughout the United States under fluctuations in the prevailing climatic conditions. This data set, c...

  2. Tree ring records reconstruct streamflow variability in Utah

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2014-02-01

    People in northern Utah, including Salt Lake City, depend on water stored as winter snow and delivered by mountain streams to populated areas. Climate models predict that in the near future, warmer temperatures will lead to a decrease in winter snow and streamflow in mountain streams, possibly leading to water shortages for the region.

  3. Estimating uncertainty of streamflow simulation using Bayesian neural networks

    NASA Astrophysics Data System (ADS)

    Zhang, Xuesong; Liang, Faming; Srinivasan, Raghavan; van Liew, Michael

    2009-02-01

    Recent studies have shown that Bayesian neural networks (BNNs) are powerful tools for providing reliable hydrologic prediction and quantifying the prediction uncertainty. The reasonable estimation of the prediction uncertainty, a valuable tool for decision making to address water resources management and design problems, is influenced by the techniques used to deal with different uncertainty sources. In this study, four types of BNNs with different treatments of the uncertainties related to parameters (neural network's weights) and model structures were applied for uncertainty estimation of streamflow simulation in two U.S. Department of Agriculture Agricultural Research Service watersheds (Little River Experimental Watershed in Georgia and Reynolds Creek Experimental Watershed in Idaho). An advanced Markov chain Monte Carlo algorithm, evolutionary Monte Carlo, was used to train the BNNs and to estimate uncertainty limits of streamflow simulation. The results obtained in these two case study watersheds show that the 95% uncertainty limits estimated by different types of BNNs are different from each other. The BNNs that only consider the parameter uncertainty with noninformative prior knowledge contain the least number of observed streamflow data in their 95% uncertainty bound. By considering variable model structure and informative prior knowledge, the BNNs can provide more reasonable quantification of the uncertainty of streamflow simulation. This study stresses the need for improving understanding and quantifying methods of different uncertainty sources for effective estimation of uncertainty of hydrologic simulation using BNNs.

  4. Water balance models in one-month-ahead streamflow forecasting.

    USGS Publications Warehouse

    Alley, W.M.

    1985-01-01

    Techniques are tested that incorporate information from water balance models in making 1-month-ahead streamflow forecasts in New Jersey. The results are compared to those based on simple autoregressive time series models. The relative performance of the models is dependent on the month of the year in question. -from Author

  5. Flood frequency in Texas; calculation of peak-streamflow frequency at gaging stations

    USGS Publications Warehouse

    Asquith, William H.; Slade, Raymond M., Jr.

    1995-01-01

    In 1991, the U.S. Geological Survey (USGS) began a 5-year study of floods in Texas. The study, which is being done in cooperation with the Texas Department of Transportation, uses streamflow data collected at streamflow-gaging stations to assess Texas flood characteristics. Two major objectives of the study are to determine for unregulated, rural basins (1) the most reliable method to calculate peak-streamflow frequency for Texas stations; and (2) a method to estimate peak-streamflow frequency at any Texas stream site (gaged or ungaged) using pertinent peak-streamflow information from nearby stations. This fact sheet pertains to the first objective of the study.

  6. Streamflow Characteristics of Streams in the Helmand Basin, Afghanistan

    USGS Publications Warehouse

    Williams-Sether, Tara

    2008-01-01

    A majority of the Afghan population lacks adequate and safe supplies of water because of contamination, lack of water-resources management regulation, and lack of basic infrastructure, compounded by periods of drought and seasonal flooding. Characteristics of historical streamflows are needed to assist with efforts to quantify the water resources of the Helmand Basin. The Helmand Basin is the largest river basin in Afghanistan. It comprises the southern half of the country, draining waters from the Sia Koh Mountains in Herat Province to the eastern mountains in Gardez Province (currently known as the Paktia Province) and the Parwan Mountains northwest of Kabul, and finally draining into the unique Sistan depression between Iran and Afghanistan (Favre and Kamal, 2004). The Helmand Basin is a desert environment with rivers fed by melting snow from the high mountains and infrequent storms. Great fluctuations in streamflow, from flood to drought, can occur annually. Knowledge of the magnitude and time distribution of streamflow is needed to quantify water resources and for water management and environmental planning. Agencies responsible for the development and management of Afghanistan's surface-water resources can use this knowledge for making safe, economical, and environmentally sound water-resource planning decisions. To provide the Afghan managers with necessary streamflow information, the U.S. Geological Survey (USGS), in cooperation with the U.S. Agency for International Development (USAID), computed streamflow statistics for data collected at historical gaging stations within the Helmand Basin. The historical gaging stations used are shown in figure 1 and listed in table 1.

  7. Global separation of plant transpiration from groundwater and streamflow

    NASA Astrophysics Data System (ADS)

    Evaristo, Jaivime; Jasechko, Scott; McDonnell, Jeffrey J.

    2015-09-01

    Current land surface models assume that groundwater, streamflow and plant transpiration are all sourced and mediated by the same well mixed water reservoir--the soil. However, recent work in Oregon and Mexico has shown evidence of ecohydrological separation, whereby different subsurface compartmentalized pools of water supply either plant transpiration fluxes or the combined fluxes of groundwater and streamflow. These findings have not yet been widely tested. Here we use hydrogen and oxygen isotopic data (2H/1H (δ2H) and 18O/16O (δ18O)) from 47 globally distributed sites to show that ecohydrological separation is widespread across different biomes. Precipitation, stream water and groundwater from each site plot approximately along the δ2H/δ18O slope of local precipitation inputs. But soil and plant xylem waters extracted from the 47 sites all plot below the local stream water and groundwater on the meteoric water line, suggesting that plants use soil water that does not itself contribute to groundwater recharge or streamflow. Our results further show that, at 80% of the sites, the precipitation that supplies groundwater recharge and streamflow is different from the water that supplies parts of soil water recharge and plant transpiration. The ubiquity of subsurface water compartmentalization found here, and the segregation of storm types relative to hydrological and ecological fluxes, may be used to improve numerical simulations of runoff generation, stream water transit time and evaporation-transpiration partitioning. Future land surface model parameterizations should be closely examined for how vegetation, groundwater recharge and streamflow are assumed to be coupled.

  8. Toward an Ensemble Streamflow Forecast Over the Entire France

    NASA Astrophysics Data System (ADS)

    Rousset, F.; Habets, F.; Noilhan, J.; Morel, S.; Le Moigne, P.

    2004-12-01

    Since the year 2003, the French National Weather Service (Meteo-France) uses an operationnal real-time system that provides a daily monitoring of the water budget, streamflows and aquifer levels over the entire France : the SAFRAN-ISBA-MODCOU (SIM) system. This coupled model is composed of the ISBA surface scheme and of the distributed hydrological model MODCOU. The system is used in a forced mode, with the atmospheric forcing derived from observations through the use of the SAFRAN analysis system. Such a system has been validated over 3 large french basins~: the Rhone, the Adour-Garonne and the Seine basins. It was shown that the system satisfactorily reproduces the water and energy budgets, as well as the observed streamflows, aquifer levels and snow-packs. In particular, the main long-duration floods of the Seine are well simulated. The SIM system is also used for streamflow forecasting. As a first step, experiments of determinist forecasts have been performed over the Rhone basin, using 2- and 3-day quantitive precipitation forecast. The encouraging results showed the potential of SIM for flood forecasting. As a next step, an ensemble streamflow prediction system is now being built. The forecasts from the Ensemble Prediction System of the ECMWF are used to force the system. The initial conditions of soil moisture, aquifer levels, etc. are given by the operationnal run of SIM, and the results are analysed for each forecast day. This system is expected to give 10-day forecasts of the streamflow of the main french rivers with a measure of the associated confidence, which is greatly valuable for flood warning and water management.

  9. Comparison of methods for computing streamflow statistics for Pennsylvania streams

    USGS Publications Warehouse

    Ehlke, Marla H.; Reed, Lloyd A.

    1999-01-01

    Methods for computing streamflow statistics intended for use on ungaged locations on Pennsylvania streams are presented and compared to frequency distributions of gaged streamflow data. The streamflow statistics used in the comparisons include the 7-day 10-year low flow, 50-year flood flow, and the 100-year flood flow; additional statistics are presented. Streamflow statistics for gaged locations on streams in Pennsylvania were computed using three methods for the comparisons: 1) Log-Pearson type III frequency distribution (Log-Pearson) of continuous-record streamflow data, 2) regional regression equations developed by the U.S. Geological Survey in 1982 (WRI 82-21), and 3) regional regression equations developed by the Pennsylvania State University in 1981 (PSU-IV). Log-Pearson distribution was considered the reference method for evaluation of the regional regression equations. Low-flow statistics were computed using the Log-Pearson distribution and WRI 82-21, whereas flood-flow statistics were computed using all three methods. The urban adjustment for PSU-IV was modified from the recommended computation to exclude Philadelphia and the surrounding areas (region 1) from the adjustment. Adjustments for storage area for PSU-IV were also slightly modified. A comparison of the 7-day 10-year low flow computed from Log-Pearson distribution and WRI-82- 21 showed that the methods produced significantly different values for about 7 percent of the state. The same methods produced 50-year and 100-year flood flows that were significantly different for about 24 percent of the state. Flood-flow statistics computed using Log-Pearson distribution and PSU-IV were not significantly different in any regions of the state. These findings are based on a statistical comparison using the t-test on signed ranks and graphical methods.

  10. Using Ensemble Streamflows for Power Marketing at Bonneville Power Administration

    NASA Astrophysics Data System (ADS)

    Barton, S. B.; Koski, P.

    2014-12-01

    Bonneville Power Administration (BPA) is a federal non-profit agency within the Pacific Northwest responsible for marketing the power generated from 31 federal hydro projects throughout the Columbia River Basin. The basin encompasses parts of five states and portions of British Columbia, Canada. BPA works with provincial entities, federal and state agencies, and tribal members to manage the water resources for a variety of purposes including flood risk management, power generation, fisheries, irrigation, recreation, and navigation. This basin is subject to significant hydrologic variability in terms of seasonal volume and runoff shape from year to year which presents new water management challenges each year. The power generation planning group at BPA includes a team of meteorologists and hydrologists responsible for preparing both short-term (up to three weeks) and mid-term (up to 18 months) weather and streamflow forecasts including ensemble streamflow data. Analysts within the mid-term planning group are responsible for running several different hydrologic models used for planning studies. These models rely on these streamflow ensembles as a primary input. The planning studies are run bi-weekly to help determine the amount of energy available, or energy inventory, for forward marketing (selling or purchasing energy up to a year in advance). These studies are run with the objective of meeting the numerous multi-purpose objectives of the basin under the various streamflow conditions within the ensemble set. In addition to ensemble streamflows, an ensemble of seasonal volume forecasts is also provided for the various water conditions in order to set numerous constraints on the system. After meeting all the various requirements of the system, a probabilistic energy inventory is calculated and used for marketing purposes.

  11. Global separation of plant transpiration from groundwater and streamflow.

    PubMed

    Evaristo, Jaivime; Jasechko, Scott; McDonnell, Jeffrey J

    2015-09-01

    Current land surface models assume that groundwater, streamflow and plant transpiration are all sourced and mediated by the same well mixed water reservoir--the soil. However, recent work in Oregon and Mexico has shown evidence of ecohydrological separation, whereby different subsurface compartmentalized pools of water supply either plant transpiration fluxes or the combined fluxes of groundwater and streamflow. These findings have not yet been widely tested. Here we use hydrogen and oxygen isotopic data ((2)H/(1)H (δ(2)H) and (18)O/(16)O (δ(18)O)) from 47 globally distributed sites to show that ecohydrological separation is widespread across different biomes. Precipitation, stream water and groundwater from each site plot approximately along the δ(2)H/δ(18)O slope of local precipitation inputs. But soil and plant xylem waters extracted from the 47 sites all plot below the local stream water and groundwater on the meteoric water line, suggesting that plants use soil water that does not itself contribute to groundwater recharge or streamflow. Our results further show that, at 80% of the sites, the precipitation that supplies groundwater recharge and streamflow is different from the water that supplies parts of soil water recharge and plant transpiration. The ubiquity of subsurface water compartmentalization found here, and the segregation of storm types relative to hydrological and ecological fluxes, may be used to improve numerical simulations of runoff generation, stream water transit time and evaporation-transpiration partitioning. Future land surface model parameterizations should be closely examined for how vegetation, groundwater recharge and streamflow are assumed to be coupled. PMID:26333467

  12. Fate and Transport of Road Salt During Snowmelt Through a Calcareous Fen: Kampoosa Bog, Stockbridge, Massachusetts

    NASA Astrophysics Data System (ADS)

    Rhodes, A. L.; Guswa, A. J.; Pufall, A.

    2007-12-01

    Kampoosa Bog is the largest and most ecologically diverse calcareous lake-basin fen in Massachusetts. Situated within a 4.7 km2 drainage basin, the open fen (approx. 20 acres) consists of a floating mat of sedges (incl. Carex aquatilis and Cladium mariscoides) that overlie peat and lake clay deposits. Mineral weathering of marble bedrock within the drainage basin supplies highly alkaline ground and surface waters to the fen basin. The natural chemistry has been greatly altered by road salt runoff from the Massaschusetts Turnpike, and in question is whether disturbance from the Turnpike and a gas pipline has facilitated aggressive growth by the invasive species Phragmites australis. Considered to be one of the most significant rare species habitats in the state, Massachusetts has designated Kampoosa Bog an Area of Critical Environmental Concern, and a committee representing several local, regional, and state agencies, organizations, and citizens manages the wetland. The purpose of this study is to characterize the hydrologic and chemical response of the wetland during snowmelt events to understand the fate and movement of road salt (NaCl). Concentrations of Na and Cl in the fen groundwater are greatest close to the Turnpike. Concentrations decrease with distance downstream but are still greatly elevated relative to sites upstream of the Turnpike. During snowmelt events, the fen's outlet shows a sharp rise in Na and Cl concentrations at the onset of melting that is soon diluted by the added meltwater. The Na and Cl flux, however, is greatest at peak discharge, suggesting that high-flow events are significant periods of export of dissolved salts from the fen. Pure dissolution of rock salt produces an equal molar ratio between Na and Cl, and sodium and chloride imbalances in stream and ground waters suggest that ~20% of the Na is stored on cation exchange sites within the peat. The largest imbalances between Na and Cl occur deeper within the peat, where the peat is

  13. Quantifying All-wave Radiation in Discontinuous Canopies with Application to Snowmelt Prediction

    NASA Astrophysics Data System (ADS)

    Lawler, R.; Link, T. E.

    2009-12-01

    Prediction and management of water resources of western North America, and similar regions of the world, is an increasing challenge for hydrologists as demands exceed available water resources, especially in arid and semi-arid regions. Seasonal snowmelt is largely driven by net radiation, which is strongly affected by vegetation canopies. Although considerable research has been conducted in continuous forests, our current understanding of radiative regimes in discontinuous forests during the snow season is limited. Theoretical results indicate the radiative regime in small canopy gaps may be distinctly different from open areas and closed-canopy forests, rather than intermediate between the two end-members depending on solar angle. To improve our understanding of radiation dynamics in discontinuous forests, a theoretical, spatially explicit, all-wave radiation model was developed. The model was tested using detailed measurements collected with radiometer arrays consisting of 21 pyranometers and 15 pyrgeometers. Data collection occurred at Marmot Creek Research Basin in Kananaskis Valley, Alberta, Canada in March 2006 and at the University of Idaho Experimental Forest, in northern Idaho, USA in March 2007 and February 2008. The model was used to simulate incoming radiation at a level site in northern Idaho across gap sizes with diameters of 1H, 2H, 3H, 4H, and 6H (where H is the average height of the surrounding forest edge). Results indicate gap sizes of 1H to 2H are the optimum gap dimensions in the discontinuous forest for receiving minimal incoming radiation load and hence greatest potential to delay snowmelt. The model indicates radiation minima persist on the southern edges of gaps (1H to 6H) from Feb 1 to May 1 at lengths ranging from 53m to 14m respectively. Future work will further develop the model by including effects of slope, aspect, and canopy density. Potential outcomes of this work are improved snowmelt prediction in complex montane landscapes, and

  14. Understanding future projected changes and trends in extreme precipitation and streamflow events in ten Polish catchments

    NASA Astrophysics Data System (ADS)

    Meresa, Hadush; Romanowicz, Renata; Napiorkoski, Jaroslaw

    2016-04-01

    The aim of the study is to investigate methods of trend detection in hydro-climatic high and low indices using novel and conventional tools, for future climate projections in the periods 2021-2050 and 2071-2100. The climate meteorological projections are obtained from regional climate models or/and global circulation models forced with IPCC SRES A1B, RCP4.5 and RCP8.5 emission scenarios. The study area includes ten catchments in Poland. The catchments have diverse hydro-climatic conditions. They are covered mostly by forest and are semi-natural. The flood regime of all the catchments is driven either by rainfall and/or snow-melt. Streamflow projections are provided by running the HBV hydrological model, coupled with climate models for the catchments. The trends are analyzed using a conventional Modified Mann Kendall statistical approach, a time frequency approach based on wavelet discrete transform (DWT) and the Dynamic Harmonic Regression (DHR) method. We address the problems of auto-correlation, seasonality and inter-annual variability of the derived indices. A Modified Mann Kendall (MMK) method is applied to cope with the autocorrelation of the time series. The DHR method is based on the unobserved component approach. Together with estimates of the components, the uncertainty of the estimates is also calculated. The results of the DHR analysis (trend) are compared with the calculated MMK and DWT trends. Among other indices we study the temporal patterns of the Standardized Precipitation Index (SPI), Standardized Runoff Index (SRI) and Standardized Evapotranspiration Index (SPEI), as well as Maximum Annual Flows and Minimum Annual Flows. The results indicate that changes in the trends of the projected indices are more conservative when DHR methods are applied than conventional trend techniques. The wavelet-based approach is the most subjective and gives the least conservative trend estimates. Trends indicate an increase in the amount of precipitation, followed by

  15. Fitting Three- and Four-Parameter Probability Distributions to Daily Streamflow

    NASA Astrophysics Data System (ADS)

    Archfield, S. A.; Vogel, R. M.

    2014-12-01

    Daily streamflow information is critical for solving any number of hydrologic problems. One promising approach to estimate a time series of daily streamflow at an ungauged location is to estimate a continuous, daily, period-of-record flow-duration curve (FDC) at the ungauged location and use the timing of observed streamflows from a donor streamgauge to transform the FDC at the ungauged location into a time series of streamflow. Ideally, if one were to find a suitable probability density function (pdf) to represent daily streamflow, only the parameters of the distribution would need to be estimated at the ungauged location. Determining the pdf of daily streamflow could also provide functional linkages between the pdfs of daily precipitation and other catchment processes toward a probabilistic framework which explains how catchments filter the precipitation signal. Three- and four parameter distributions were fit to daily streamflow observations from streamgauges located in the north- and southeastern United States. No suitable three or four-parameter probability distribution were found to adequately represent the distribution of daily streamflow, particularly at streamflow quantiles greater than 0.9 and less than 0.01 exceedence probabilities. Furthermore, the properties of these distributions caused estimated streamflows to be bounded at both the highest and lowest streamflow quantiles, creating a severe bias in the estimation of the FDC. Traditional goodness-of-fit statistics were also unable to revealing this lack of fit; only examination of the individual probability plots showed this inadequacy.

  16. The Significance of Deep Groundwater Contributions to Streamflow in a Crystalline Bedrock Mountain Watershed

    NASA Astrophysics Data System (ADS)

    Tolley, D. G.; Frisbee, M. D.; Harding, J.; Wilson, J. L.

    2013-12-01

    In western states, such as New Mexico, most surface water is derived from high-elevation mountainous watersheds. Unfortunately, the interaction between groundwater and surface water within mountain systems is poorly understood. While most research on streamflow generation has been conducted at the hillslope scale, there are significant limitations when attempting to upscale these processes to an entire basin. Recent work by Frisbee et al. (2011) in the mountainous Saguache watershed (~1600 km^2) of southern Colorado has shown a significant portion of streamflow is controlled by old (>1000 yrs) groundwater inputs, and this old groundwater greatly influences stream geochemistry and residence time distributions. Is the deep-groundwater conceptual model developed for the volcanic-rich Saguache transferable to other watersheds with different drainage areas and geologic settings, and larger human population? We apply the conceptual model developed for Saguache to the Rio Hondo, a mesoscale (~200 km^2) watershed in northern New Mexico with crystalline basement rock that has been extensively fractured due to tectonic activity. We hypothesize that the enhanced secondary permeability of the basement rock allows for significant groundwater flow through the mountain block, a portion of which is eventually discharged to the surface water system. Upwelling from this deep, more geochemically evolved groundwater would be expected to increase moving from the headwaters to the outlet. Geochemical data collected from the Rio Hondo strongly supports this hypothesis. Surface water solute concentrations for most constituents increase as a function of the drainage area while the stable isotopic signature remains constant (both spatially and temporally), indicating that while nearly all water in the basin is sourced from winter and spring precipitation it has undergone differing degrees of geochemical evolution along different flow paths. End-member mixing analysis (EMMA) performed on

  17. Streamflow analysis of the Apalachicola, Pearl, Trinity, and Nueces River basins, southeastern United States

    USGS Publications Warehouse

    Greene, K.E.; Slade, R.M., Jr.

    1995-01-01

    Annual mean and annual minimum and maximum daily mean streamflow were compared with associated annual index precipitation for sites on the main channel and tributaries of the Apalachicola, Pearl, Trinity, and Nueces Rivers in the Gulf of Mexico Basin. Precipitation and annual minimum streamflow at the downstream station on each river increased over the available periods of record. No long-term changes were identified in mean and maximum streamflow to the Gulf from the Apalachicola River Basin. Annual mean and maximum streamflow to the Gulf increased with time from the Pearl River Basin and decreased from the Trinity River Basin. Annual mean streamflow showed varied trends and annual maximum streamflow decreased for the Nueces River Basin. Short-term trends in streamflow and precipitation generally corresponded at most stations. Total reported surface-water withdrawals from the Trinity River Basin increased more than fourfold since 1940 and currently represent about one-fourth of the mean streamflow near the mouth of the river. Total reported withdrawals from the Nueces River Basin increased more than eightfold since 1940 and currently represent about one-third of the annual mean streamflow near the mouth. Predicted peak streamflow into the Gulf from the Apalachicola River was 23 percent less for the 50-year peak streamflow after reservoirs were constructed. Annual mean streamflow to the Gulf was reduced following construction of the downstream reservoirs on the Apalachicola and Trinity Rivers. Peak streamflows from the Pearl and Trinity Rivers have not been affected. The annual mean streamflow from the Nueces River was reduced by about 24 percent as a result of filling and evaporation at Choke Canyon Reservoir.

  18. Spatially distributed energy balance snowmelt modeling in a mountainous river basin: estimation of meteorological inputs and verification of model results

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A spatially distributed energy balance snowmelt model has been applied to a 2150 km2 drainage basin in the Boise River, ID, USA, to simulate the accumulation and melt of the snowpack for the years 1998–2000. The simulation was run at a 3 h time step and a spatial resolution of 250 m. Spatial field t...

  19. Changes In Snowmelt Timing In Response To Pine Beetle Infestation In Lodgepole Pines In The Colorado Rockies

    NASA Astrophysics Data System (ADS)

    Pugh, E.; Tilton, E. S.

    2008-12-01

    Since 1996, roughly 1.5 million acres of lodgepole pine forest in Colorado have been infested by mountain pine beetles (Dendroctonus ponderosae). We measured physical snowpack properties (depth, density, and temperature) under stands of both living and dead lodgepole pines in the Colorado Rockies. This data allowed us to investigate the effect of increased forest canopy transmittance due to tree death on potential advances in the annual hydrograph. We compared snow accumulation and melt on north-facing and south- facing slopes at an elevation of approximately 3000m. As expected, topography-dominated solar forcing is the chief factor in snowmelt: snow on south-facing slopes melted earlier in the season than north-facing slopes. Comparing stands of dead and live trees within topographic zones revealed a few dramatic differences: snow water equivalent was lower and mean snowpack temperature was warmer in dead lodgepole pine stands. Temperature timeseries from within the snowpack suggest that snow in dead tree stands became isothermal sooner than snow in living tree stands. Together these show that there was indeed earlier snowmelt in lodgepole pine forest regions infested with mountain pine beetle. Earlier snowmelt will likely cause peak snowmelt discharge to occur sooner.

  20. Small-scale drivers: the importance of nutrient availability and snowmelt timing on performance of the alpine shrub Salix herbacea.

    PubMed

    Little, Chelsea J; Wheeler, Julia A; Sedlacek, Janosch; Cortés, Andrés J; Rixen, Christian

    2016-04-01

    Alpine plant communities are predicted to face range shifts and possibly extinctions with climate change. Fine-scale environmental variation such as nutrient availability or snowmelt timing may contribute to the ability of plant species to persist locally; however, variation in nutrient availability in alpine landscapes is largely unmeasured. On three mountains around Davos, Switzerland, we deployed Plant Root Simulator probes around 58 Salix herbacea plants along an elevational and microhabitat gradient to measure nutrient availability during the first 5 weeks of the summer growing season, and used in situ temperature loggers and observational data to determine date of spring snowmelt. We also visited the plants weekly to assess performance, as measured by stem number, fruiting, and herbivory damage. We found a wide snowmelt gradient which determined growing season length, as well as variations of an order of magnitude or more in the accumulation of 12 nutrients between different microhabitats. Higher nutrient availability had negative effects on most shrub performance metrics, for instance decreasing stem number and the proportion of stems producing fruits. High nutrient availability was associated with increased herbivory damage in early-melting microhabitats, but among late-emerging plants this pattern was reversed. We demonstrate that nutrient availability is highly variable in alpine settings, and that it strongly influences performance in an alpine dwarf shrub, sometimes modifying the response of shrubs to snowmelt timing. As the climate warms and human-induced nitrogen deposition continues in the Alps, these factors may contribute to patterns of local plants persistence. PMID:26235963

  1. Natural selection favors rapid reproductive phenology in Potentilla pulcherrima (Rosaceae) at opposite ends of a subalpine snowmelt gradient.

    PubMed

    Stinson, Kristina A

    2004-04-01

    In high altitude plants, flowering quickly ensures reproductive success within a short snow-free period, but limits maturation time and fecundity. Natural selection on prefloration intervals may therefore vary in contrasting snowmelt environments and could influence the outcome of phenological responses to climatic change. This study investigated adaptive differentiation and plasticity of prefloration intervals in the subalpine perennial Potentilla pulcherrima. Three years of in situ field observations were combined with phenotypic selection analyses and a common garden experiment. Plants from high, intermediate, and low altitudes expressed similar prefloration intervals and plasticity when grown at common altitude, indicating no evidence for adaptive differentiation. Selection on the prefloration interval was negative at both low and high altitudes before and after accounting for strong positive selection on size. Environmental differences between high and low altitudes indicated that long, dry seasons and short, wet seasons both favored rapid reproduction. Therefore, quicker reproduction was adaptive in response to late snowmelt, but slower reproduction in response to earlier snowmelt appeared to be maladaptive. Selection differed marginally between late snowmelt years and dry ones. Plastic responses to future precipitation patterns may therefore have positive or negative effects on fitness within a single species, depending upon altitude and year. PMID:21653408

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  3. Performance of the snowmelt runoff model when remotely-sensed estimates of snow covered area are not available

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Snowmelt Runoff Model (SRM) is usually run with snow cover depletion data. These daily depletion data can be derived through interpolation of periodic, remotely sensed measurements of basin snow covered area (SCA). It is also possible to run SRM successfully without snow depletion data in “no sn...

  4. Snowmelt-driven changes in dissolved organic matter and bacterioplankton communities in the Heilongjiang watershed of China.

    PubMed

    Qiu, Linlin; Cui, Hongyang; Wu, Junqiu; Wang, Baijie; Zhao, Yue; Li, Jiming; Jia, Liming; Wei, Zimin

    2016-06-15

    Bacterioplankton plays a significant role in the circulation of materials and ecosystem function in the biosphere. Dissolved organic matter (DOM) from dead plant material and surface soil leaches into water bodies when snow melts. In our study, water samples from nine sampling sites along the Heilongjiang watershed were collected in February and June 2014 during which period snowmelt occurred. The goal of this study was to characterize changes in DOM and bacterioplankton community composition (BCC) associated with snowmelt, the effects of DOM, environmental and geographical factors on the distribution of BCC and interactions of aquatic bacterioplankton populations with different sources of DOM in the Heilongjiang watershed. BCC was measured by denaturing gradient gel electrophoresis (DGGE). DOM was measured by excitation-emission matrix (EEM) fluorescence spectroscopy. Bacterioplankton exhibited a distinct seasonal change in community composition due to snowmelt at all sampling points except for EG. Redundancy analysis (RDA) indicated that BCC was more closely related to DOM (Components 1 and 4, dissolved organic carbon, biochemical oxygen demand and chlorophyll a) and environmental factors (water temperature and nitrate nitrogen) than geographical factors. Furthermore, DOM had a greater impact on BCC than environmental factors (29.80 vs. 15.90% of the variation). Overall, spring snowmelt played an important role in altering the quality and quantity of DOM and BCC in the Heilongjiang watershed. PMID:26974572

  5. Snowmelt and Infiltration Deficiencies of SSiB and Their Resolution with a New Snow-Physics Scheme

    NASA Technical Reports Server (NTRS)

    Sud, Y. C.; Mocko, David M.

    1999-01-01

    A two-year 1987-1988 integration of SSiB forced with ISLSCP Initiative I surface data (as part of the Global Soil Wetness Project, GSWP, evaluation and intercomparison) produced generally realistic land surface fluxes and hydrology. Nevertheless, the evaluation also helped to identify some of the deficiencies of the current version of the Simplified Simple Biosphere (SSiB) model. The simulated snowmelt was delayed in most regions, along with excessive runoff and lack of an spring soil moisture recharge. The SSIB model had previously been noted to have a problem producing accurate soil moisture as compared to observations in the Russian snowmelt region. Similarly, various GSWP implementations of SSIB found deficiencies in this region of the simulated soil moisture and runoff as compared to other non-SSiB land-surface models (LSMs). The origin of these deficiencies was: 1) excessive cooling of the snow and ground, and 2) deep frozen soil disallowing snowmelt infiltration. The problem was most severe in regions that experience very cold winters. In SSiB, snow was treated as a unified layer with the first soil layer, causing soil and snow to cool together in the winter months, as opposed to snow cover acting as an insulator. In the spring season, a large amount of heat was required to thaw a hard frozen snow plus deep soil layers, delaying snowmelt and causing meltwater to become runoff over the frozen soil rather than infiltrate into it.

  6. Climatic controls on the snowmelt hydrology of the northern Rocky Mountains

    USGS Publications Warehouse

    Pederson, G.T.; Gray, S.T.; Ault, T.; Marsh, W.; Fagre, D.B.; Bunn, A.G.; Woodhouse, C.A.; Graumlich, L.J.

    2011-01-01

    The northern Rocky Mountains (NRMs) are a critical headwaters region with the majority of water resources originating from mountain snowpack. Observations showing declines in western U.S. snowpack have implications for water resources and biophysical processes in high-mountain environments. This study investigates oceanic and atmospheric controls underlying changes in timing, variability, and trends documented across the entire hydroclimatic-monitoring system within critical NRM watersheds. Analyses were conducted using records from 25 snow telemetry (SNOTEL) stations, 148 1 April snow course records, stream gauge records from 14 relatively unimpaired rivers, and 37 valley meteorological stations. Over the past four decades, midelevation SNOTEL records show a tendency toward decreased snowpack with peak snow water equivalent (SWE) arriving and melting out earlier. Temperature records show significant seasonal and annual decreases in the number of frost days (days ???0??C) and changes in spring minimum temperatures that correspond with atmospheric circulation changes and surface-albedo feedbacks in March and April. Warmer spring temperatures coupled with increases in mean and variance of spring precipitation correspond strongly to earlier snowmeltout, an increased number of snow-free days, and observed changes in streamflow timing and discharge. The majority of the variability in peak and total annual snowpack and streamflow, however, is explained by season-dependent interannual-to-interdecadal changes in atmospheric circulation associated with Pacific Ocean sea surface temperatures. Over recent decades, increased spring precipitation appears to be buffering NRM total annual streamflow from what would otherwise be greater snow-related declines in hydrologic yield. Results have important implications for ecosystems, water resources, and long-lead-forecasting capabilities. ?? 2011 American Meteorological Society.

  7. An organized signal in snowmelt runoff over the western United States

    USGS Publications Warehouse

    Peterson, D.H.; Smith, R.E.; Dettinger, M.D.; Cayan, D.R.; Riddle, L.

    2000-01-01

    Daily-to-weekly discharge during the snowmelt season is highly correlated among river basins in the upper elevations of the central and southern Sierra Nevada (Carson, Walker, Tuolumne, Merced, San Joaquin, Kings, and Kern Rivers). In many cases, the upper Sierra Nevada watershed operates in a single mode (with varying catchment amplitudes). In some years, with appropriate lags, this mode extends to distant mountains. A reason for this coherence is the broad scale nature of synoptic features in atmospheric circulation, which provide anomalous insolation and temperature forcings that span a large region, sometimes the entire western U.S. These correlations may fall off dramatically, however, in dry years when the snowpack is spatially patchy.

  8. Snowmelt and rain in a marginal snowpack watershed: Amount and duration of water input controls runoff

    NASA Astrophysics Data System (ADS)

    Anderson, S. P.; Rock, N.

    2013-12-01

    Snowmelt predictably delivers a concentrated pulse of water to watersheds, and therefore structures ecosystems and human water management. The deep irrigation from snowmelt also delivers water effectively to the base of the critical zone in water-limited climates, and hence controls the advance of the weathering front. Changes in snowmelt therefore stand as a prominent concern for the impacts of future climate warming. We use a headwater watershed in the Colorado Front Range to explore the impacts of varying delivery of rain and snow on runoff. Gordon Gulch, a 2.7 km2 forested watershed at 2650 m elevation in the Colorado Front Range, is drained by a small first order stream. A snowpack builds on north-facing slopes, while snow comes and goes on south-facing slopes. In water years 2010-2012, total precipitation ranged from 480 to 560 mm. Total runoff, which ranged from 55 to 102 mm, does not correlate with annual precipitation. Over half of the total annual discharge occurs in a period of a few weeks each year; in two of the study years, peak discharge occurred in spring following snowmelt. In one year, peak discharge was entirely rain driven. In 2010 and 2011, discharge peaked during late spring (May) storms after the snow pack melted. The highest annual runoff, and longest duration high discharge period, occurred in water year 2010. In that year, ablation of most of a ~70 cm snowpack (on N-facing slopes; S facing slopes were bare) was followed by a 25 day stormy period in which ~130 mm of mixed rain and snow fell. Two discharge maxima occurred in response to precipitation events during this wet, post-snowpack period. In total, discharge remained high for ~6 weeks. In water year 2011, a smaller snowpack (max. ~30 cm), and drier spring produced a much more compact high runoff season of ~2 weeks. Although water year 2011 had ~10% more total precipitation, it produced 30% less runoff than water year 2010. A greater proportion of the 2011 precipitation fell in summer

  9. Hydrologic and biotic control of nitrogen export during snowmelt: A combined conservative and reactive tracer approach

    NASA Astrophysics Data System (ADS)

    Petrone, Kevin; Buffam, Ishi; Laudon, Hjalmar

    2007-06-01

    Dissolved inorganic nitrogen (DIN) and dissolved organic nitrogen (DON) stored in the snowpack are important sources of N in snow-covered ecosystems, yet we have limited knowledge of their fate during the melt period. Our objective was to quantify the role of hydrologic and biogeochemical processes in regulating stream fluxes of DIN (NO3- + NH4+) and DON in a forest-dominated and a wetland-dominated catchment during the snowmelt period. We combined isotopic hydrograph separation with concurrent measurements of meltwater DIN and DON to calculate "conservative" N export (hydrologic mixing only) and compared it with "reactive" N export (i.e., observed fluxes that include biogeochemical processes). On balance, N was retained in the catchments during snowmelt because of storage of meltwater N in soils, but our N export comparison revealed N generation (mostly as DON) from the mobilization of dissolved organic matter. In contrast, NO3-, which was highly enriched in snowpack meltwater, remained below detection in streams, and both catchments were sinks for NO3-, suggesting that denitrification and/or uptake may be important at the catchment scale. Over the melt period, the forest catchment was a greater total N source because of the convergence of lateral flow and near-stream riparian N sources in surface soils, which elevated stream DON and to a lesser extent NH4+. In contrast, preferential flow in the wetland catchment tended to dilute DIN in saturated peatland soils and in the stream, whereas DON varied little over time. These findings highlight the importance of hydrologic processes that store meltwater N in catchment soils but at the same time deliver DON from riparian sources to the stream. Further, model results suggest that biotic uptake and/or sorption effectively retain much of the meltwater DIN from the snowpack. Collectively, hydrologic storage and biogeochemical processes act to retain N that is likely important for boreal ecosystem production later in the

  10. Implications of mountain shading on calculating energy for snowmelt using unstructured triangular meshes

    NASA Astrophysics Data System (ADS)

    Marsh, C.; Pomeroy, J. W.; Spiteri, R.

    2012-12-01

    In many parts of the world, the snowmelt energy balance is dominated by net solar shortwave radiation. This is the case in the Canadian Rocky Mountains, where clear skies dominate the winter and spring. In mountainous regions, irradiance at the snow surface is not only affected by solar angles, atmospheric transmittance, and the slope and aspect of immediate topography, but also by horizon-shadows, i.e., shadows from surrounding terrain. Many hydrological models do not consider such horizon-shadows and the accumulation of errors in estimating solar irradiance by neglecting horizon-shadows may lead to significant errors in calculating the timing and rate of snowmelt due to the seasonal storage of internal energy in the snowpack. An unstructured triangular-mesh-based horizon-shading model is compared to standard self-shading algorithms in the Marmot Creek Research Basin (MCRB), Alberta, Canada. A systematic basin-wide over-prediction (basin mean expressed as phase change mass (assumed constant albedo of 0.8): 14 mm, maximum: 200 mm) in net shortwave radiation is observed when only self-shading is considered. The horizon-shadow model is run at a point scale at three sites throughout the MCRB to investigate the effects of topographic scale on the model results. In addition, the model results are compared to measurements of mountain shadows via orthorectified timelapse digital photographs and measured surface irradiance. The horizon-model irradiance data are used to drive a point-scale energy balance model, SNOBAL, via The Cold Regions Hydrological Model, an HRU-based hydrologic model. Melt timing is shown to differ by up to four days by neglecting horizon-shadows. It is further hypothesized that the errors might be much larger in basins with more rugged topography. Finally, a consideration of the intersection of unstructured-mesh and HRU landscape representations is discussed.

  11. An improved conceptual understanding of snowmelt and groundwater dynamics in the semi-arid Andes

    NASA Astrophysics Data System (ADS)

    Sproles, Eric; Hevia, Andres; Soulsby, Chris; Tetzlaff, Doerthe

    2016-04-01

    The contribution of snowmelt to groundwater has long been recognized as an important component of the hydrological cycle in semi-arid northern central Chile (29°-32°S). Despite its importance as a water resource, this transition to groundwater remains poorly understood. Climatically, the High Cordillera in northern central Chile receives approximately 10 times as much annual precipitation as the valley bottoms, falling almost exclusively as snow above 3500 m during the winter months. Geologically, the High Cordillera is characterized by steep topography and a highly dissected landscape underlain by bedrock. Groundwater stores in the mountain headwaters are assumed to be constrained to the valley bottoms. The current working hypothesis of watershed processes in the High Cordillera describes fluxes of spring melt moving through the hillslope via local flowpaths to valley aquifers that recharge streams throughout the headwater reaches. Previous studies in the region indicate Pre-Cordilleran aquifers, located in lower elevation dry ephemeral valleys, are hydrologically disconnected from the High Cordillera. These watersheds have no seasonal snowpack, and recharge occurs primarily during infrequent rain events. These isolated Pre-Cordilleran aquifers serve as an important water resource for rural residents and infrastructure. We present stable isotope, geochemical, and groundwater level data from the wet El Niño winter of 2015 that suggests a topographically disconnected aquifer in the Pre-Cordillera received considerable recharge from High Cordillera snowmelt. These novel findings are indicative of deep groundwater flow paths between the Pre- and High Cordillera during the wet winter and spring of 2015, and improve the conceptual understanding of hydrological processes in the region. Additionally, these results will directly benefit groundwater management in the Pre-Cordillera and better inform modeling efforts in the High Cordillera. While this study is limited to

  12. Non-motorized Winter Recreation Impacts to Snowmelt Erosion, Tronsen Basin, Eastern Cascades, Washington

    NASA Astrophysics Data System (ADS)

    Eagleston, Holly; Rubin, Charles

    2013-01-01

    Many recreation impact studies have focused on summer activities, but the environmental impact of winter recreation is poorly characterized. This study characterizes the impact of snowshoe/cross-country ski compaction and snowmelt erosion on trails. Trail cross-sectional profiles were measured before and after the winter season to map changes in erosion due to winter recreation. Compacted snow on the trail was 30 % more dense than snowpack off the trail before spring melt out. Snow stayed on the trail 7 days longer. Soil and organic material was transported after spring snowmelt with -9.5 ± 2.4 cm2 total erosion occurring on the trail transects and -3.8 ± 2.4 cm2 total erosion occurring on the control transect ( P = 0.046). More material was transported on the trail than on the control, 12.9± 2.4 versus 6.0 ± 2.4 cm2 ( P = 0.055), however, deposition levels remained similar on the trail and on the control. Snow compaction from snowshoers and cross-country skiers intensified erosion. Trail gradient was found to be significantly correlated to net changes in material on the trail ( R 2 = 0.89, ρ = -0.98, P = 0.005). This study provides a baseline, showing that non-motorized winter recreation does impact soil erosion rates but more studies are needed. Trail managers should consider mitigation such as water bars, culverts and avoiding building trails with steep gradients, in order to reduce loss of soils on trails and subsequent sedimentation of streams.

  13. Non-motorized winter recreation impacts to snowmelt erosion, Tronsen Basin, Eastern Cascades, Washington.

    PubMed

    Eagleston, Holly; Rubin, Charles

    2013-01-01

    Many recreation impact studies have focused on summer activities, but the environmental impact of winter recreation is poorly characterized. This study characterizes the impact of snowshoe/cross-country ski compaction and snowmelt erosion on trails. Trail cross-sectional profiles were measured before and after the winter season to map changes in erosion due to winter recreation. Compacted snow on the trail was 30 % more dense than snowpack off the trail before spring melt out. Snow stayed on the trail 7 days longer. Soil and organic material was transported after spring snowmelt with -9.5 ± 2.4 cm(2) total erosion occurring on the trail transects and -3.8 ± 2.4 cm(2) total erosion occurring on the control transect (P = 0.046). More material was transported on the trail than on the control, 12.9± 2.4 versus 6.0 ± 2.4 cm(2) (P = 0.055), however, deposition levels remained similar on the trail and on the control. Snow compaction from snowshoers and cross-country skiers intensified erosion. Trail gradient was found to be significantly correlated to net changes in material on the trail (R (2) = 0.89, ρ = -0.98, P = 0.005). This study provides a baseline, showing that non-motorized winter recreation does impact soil erosion rates but more studies are needed. Trail managers should consider mitigation such as water bars, culverts and avoiding building trails with steep gradients, in order to reduce loss of soils on trails and subsequent sedimentation of streams. PMID:23117398

  14. Tracking snowmelt in the subsurface: time-lapse electrical resistivity imaging on an alpine hill slope.

    NASA Astrophysics Data System (ADS)

    Thayer, D.; Parsekian, A.; Hyde, K.; Beverly, D.; Speckman, H. N.; Ewers, B. E.

    2015-12-01

    In the mountain West region the winter snowpack provides more than 70% of our annual water supply. Modeling and predicting the timing and magnitude of snowmelt-driven water yield is difficult due to the complexities of hydrologic systems that move meltwater from snow to rivers. Particular challenges are understanding the temporal and spatial domain of subsurface hydraulic processes at relevant scales, which range from points to catchments. Subsurface characterization often requires borehole instrumentation, which is expensive and extremely difficult to install in remote, rugged terrain. Advancements in non-invasive geophysical methods allow us to monitor changes in geophysical parameters over time and infer changes in hydraulic processes. In the No-Name experimental catchment in the Medicine Bow National Forest in Wyoming, we are conducting a multi-season, time-lapse electrical resistivity imaging survey on a sub-alpine hill slope. This south-facing, partially forested slope ranges from 5 degrees to 35 degrees in steepness and consists of a soil mantle covering buried glacial talus deposits of unknown depth. A permanent grid of down-slope and cross-slope electrode arrays is monitored up to four times a day. The arrays span the entire vertical distance of the slope, from an exposed bedrock ridge to a seasonal drainage below, and cover treed and non-treed areas. Geophysical measurements are augmented by temperature and moisture time-series instrumented below the surface in a contiguous 3 meter borehole. A time-series of multiple resistivity models each day from May to July shows the changing distribution of subsurface moisture during a seasonal drying sequence punctuated by isolated rain events. Spatial patterns of changing moisture indicate that soil and gravel in the top two meters drain into a saturated layer parallel to the slope which overlies less saturated material. These results suggest that water from snowmelt and rain events tends to move down-slope beneath

  15. Evaluation of a fine sediment removal tool in spring-fed and snowmelt driven streams

    USGS Publications Warehouse

    Sepulveda, Adam; Layhee, Megan J.; Sutphin, Zach; Sechrist, Juddson D.

    2015-01-01

    The accumulation of fine-grained sediments impairs the structure and function of streams, so removing fine sediments may be required to achieve restoration objectives. There has been little work on methods of removing excess sediment or on the efficacy of the methods. We used a 4-year before-after-control-impact design in southeastern Idaho streams to test a fine sediment removal system (FSRS) manufactured by Streamside Environmental LLC. The FSRS agitates fine sediment in the substrate with clean pump water and then vacuums the sediment out of the stream with a second pump. Our objectives were: 1) to test if the FSRS can selectively remove fine sediment; 2) to monitor the bio-physical responses in FSRS treated and downstream waters; and 3) to compare the bio-physical responses to the FSRS in spring-fed and snowmelt driven stream reaches. The FSRS removed ~ 14 metric tons of sediment from the two treated reaches. More than 90% of this sediment was < 2 mm, indicating that the FSRS selected for fine sediment in both stream types. Sustained effects of removing this sediment were confined to substrate improvements in treated reaches. Embeddedness in the spring-fed reach decreased and subsurface grain size in spring-fed and snowmelt driven reaches increased. We did not detect any sustained invertebrate or fish responses in treated reaches or any detrimental bio-physical responses in downstream waters. These results indicate that the FSRS reduced fine sediment levels but sediment removal did not reverse the impacts of sediment accumulation to stream biota within our monitoring time frame.

  16. Climate change adaptation in a highly urbanized snowmelt dominated basin in Central Chile

    NASA Astrophysics Data System (ADS)

    Vicuna, S.; Bustos, E.; Merino, P.; Henriquez Dole, L. E.; Jansen, S.; Gil, M.; Ocampo, A.; Poblete, D.; Tosoni, D.; Meza, F. J.; Donoso, G.; Melo, O.

    2015-12-01

    The Maipo river basin holds 40% of Chile's total population and produces almost half of the country's Gross Domestic Product. The basin is located in the semiarid and snowmelt dominated central region of the country and, aside from the typical pressures of growth in developing country basins, the Maipo river basin faces climate change impacts associated with a reduction in total runoff and changes in its seasonality. Surface water is the main water source for human settlements, natural ecosystems, and economic activities including agriculture, mining and hydropower production. In 2012 a research project, called MAPA (Maipo Plan de Adaptacion), began with the objective of articulating a climate variability and climate change adaptation plan for the Maipo river basin. The project engaged at the beginning a group of relevant water and land use stakeholders which allowed for a good representation of critical aspects of an adaptation plan such as the definition of objectives and performance indicators, future land use scenarios, modeling of the different components of the system and design of adaptation strategies. The presentation will highlight the main results of the research project with a special focus on the upper catchments of the basin. These results include the assessment of impacts associated with future climate and land use scenarios on key components of the hydrologic cycle including snowmelt and glacier contribution to runoff and subsequent impacts on water availability for the operation of hydropower facilities, satisfaction of instream (recreation and aquatic ecosystem) uses and provision of water for the city of Santiago (7 million people) and to irrigate more than 100,000 hectares of high value crops. The integrative approach followed in this project including different perspectives on the use of water in the basin provides a good opportunity to test the varying degree of impacts that could be associated with a given future scenario and also understand

  17. Offsetting Streamflow Depletion from Well Pumpage by Capture of Evapotranspiration

    NASA Astrophysics Data System (ADS)

    Konikow, L. F.

    2014-12-01

    It is well established that groundwater pumpage must be balanced by a loss of water elsewhere. This loss comes primarily from storage depletion at early times and increasingly from capture at later times. Capture includes some combination of increases in recharge to the aquifer and decreases in discharge from the aquifer induced by the pumpage. Most capture is manifested as streamflow depletion (e.g., through induced infiltration and/or reductions in baseflow). However, decreasing evapotransirative discharge from an aquifer would constitute a type of capture that does not affect streamflow. In his classic 1940 paper Theis recommends that wells be placed in areas where groundwater "is being lost by evaporation or transpiration by non-productive vegetation," thereby utilizing this "lost" water with a minimal lowering of the water table. This study uses numerical simulation of a hypothetical unconfined stream-aquifer system in an arid climate, where streamflow depletion is typically a major concern, to assess how capture of evapotranspiration (ET) can influence the sources of water for a pumping well when the ET losses are directly affected by spatial and temporal changes in the depth to the water table. Consequently, streamflow depletion for a given pumping rate can be affected by capture of ET and how that varies with well location and the history of development and drawdown. We assume the standard MODFLOW linear model for changes in groundwater ET as the water table declines to a specified extinction depth. In one scenario in which about half the recharge to the aquifer is lost to ET under predevelopment conditions, the percentage of well discharge balanced by decreased ET changed from 1.1% after one year to 18% after 200 years of simulated pumpage. The actual ET rate decreased from 5,372 m3/d under predevelopment conditions to 5,001 m3/d after 200 years of development (a 7% reduction in total ET losses). At this same time, 77% of pumpage is derived from streamflow

  18. An integrated modeling system for estimating glacier and snow melt driven streamflow from remote sensing and earth system data products in the Himalayas

    NASA Astrophysics Data System (ADS)

    Brown, M. E.; Racoviteanu, A. E.; Tarboton, D. G.; Gupta, A. Sen; Nigro, J.; Policelli, F.; Habib, S.; Tokay, M.; Shrestha, M. S.; Bajracharya, S.; Hummel, P.; Gray, M.; Duda, P.; Zaitchik, B.; Mahat, V.; Artan, G.; Tokar, S.

    2014-11-01

    Quantification of the contribution of the hydrologic components (snow, ice and rain) to river discharge in the Hindu Kush Himalayan (HKH) region is important for decision-making in water sensitive sectors, and for water resources management and flood risk reduction. In this area, access to and monitoring of the glaciers and their melt outflow is challenging due to difficult access, thus modeling based on remote sensing offers the potential for providing information to improve water resources management and decision making. This paper describes an integrated modeling system developed using downscaled NASA satellite based and earth system data products coupled with in-situ hydrologic data to assess the contribution of snow and glaciers to the flows of the rivers in the HKH region. Snow and glacier melt was estimated using the Utah Energy Balance (UEB) model, further enhanced to accommodate glacier ice melt over clean and debris-covered tongues, then meltwater was input into the USGS Geospatial Stream Flow Model (GeoSFM). The two model components were integrated into Better Assessment Science Integrating point and Nonpoint Sources modeling framework (BASINS) as a user-friendly open source system and was made available to countries in high Asia. Here we present a case study from the Langtang Khola watershed in the monsoon-influenced Nepal Himalaya, used to validate our energy balance approach and to test the applicability of our modeling system. The snow and glacier melt model predicts that for the eight years used for model evaluation (October 2003-September 2010), the total surface water input over the basin was 9.43 m, originating as 62% from glacier melt, 30% from snowmelt and 8% from rainfall. Measured streamflow for those years were 5.02 m, reflecting a runoff coefficient of 0.53. GeoSFM simulated streamflow was 5.31 m indicating reasonable correspondence between measured and model confirming the capability of the integrated system to provide a quantification of

  19. An Integrated Modeling System for Estimating Glacier and Snow Melt Driven Streamflow from Remote Sensing and Earth System Data Products in the Himalayas

    NASA Technical Reports Server (NTRS)

    Brown, M. E.; Racoviteanu, A. E.; Tarboton, D. G.; Sen Gupta, A.; Nigro, J.; Policelli, F.; Habib, S.; Tokay, M.; Shrestha, M. S.; Bajracharya, S.

    2014-01-01

    Quantification of the contribution of the hydrologic components (snow, ice and rain) to river discharge in the Hindu Kush Himalayan (HKH) region is important for decision-making in water sensitive sectors, and for water resources management and flood risk reduction. In this area, access to and monitoring of the glaciers and their melt outflow is challenging due to difficult access, thus modeling based on remote sensing offers the potential for providing information to improve water resources management and decision making. This paper describes an integrated modeling system developed using downscaled NASA satellite based and earth system data products coupled with in-situ hydrologic data to assess the contribution of snow and glaciers to the flows of the rivers in the HKH region. Snow and glacier melt was estimated using the Utah Energy Balance (UEB) model, further enhanced to accommodate glacier ice melt over clean and debris-covered tongues, then meltwater was input into the USGS Geospatial Stream Flow Model (Geo- SFM). The two model components were integrated into Better Assessment Science Integrating point and Nonpoint Sources modeling framework (BASINS) as a user-friendly open source system and was made available to countries in high Asia. Here we present a case study from the Langtang Khola watershed in the monsoon-influenced Nepal Himalaya, used to validate our energy balance approach and to test the applicability of our modeling system. The snow and glacier melt model predicts that for the eight years used for model evaluation (October 2003-September 2010), the total surface water input over the basin was 9.43 m, originating as 62% from glacier melt, 30% from snowmelt and 8% from rainfall. Measured streamflow for those years were 5.02 m, reflecting a runoff coefficient of 0.53. GeoSFM simulated streamflow was 5.31 m indicating reasonable correspondence between measured and model confirming the capability of the integrated system to provide a quantification

  20. Evidence for changes in the magnitude and frequency of observed rainfall vs. snowmelt driven floods in Norway

    NASA Astrophysics Data System (ADS)

    Vormoor, Klaus; Lawrence, Deborah; Schlichting, Lena; Wilson, Donna; Wong, Wai Kwok

    2016-07-01

    There is increasing evidence for recent changes in the intensity and frequency of heavy precipitation and in the number of days with snow cover in many parts of Norway. The question arises as to whether these changes are also discernable with respect to their impacts on the magnitude and frequency of flooding and on the processes producing high flows. In this study, we tested up to 211 catchments for trends in peak flow discharge series by applying the Mann-Kendall test and Poisson regression for three different time periods (1962-2012, 1972-2012, 1982-2012). Field-significance was tested using a bootstrap approach. Over threshold discharge events were classified into rainfall vs. snowmelt dominated floods, based on a simple water balance approach utilizing a nationwide 1 × 1 km2 gridded data set with daily observed rainfall and simulated snowmelt data. Results suggest that trends in flood frequency are more pronounced than trends in flood magnitude and are more spatially consistent with observed changes in the hydrometeorological drivers. Increasing flood frequencies in southern and western Norway are mainly due to positive trends in the frequency of rainfall dominated events, while decreasing flood frequencies in northern Norway are mainly the result of negative trends in the frequency of snowmelt dominated floods. Negative trends in flood magnitude are found more often than positive trends, and the regional patterns of significant trends reflect differences in the flood generating processes (FGPs). The results illustrate the benefit of distinguishing FGPs rather than simply applying seasonal analyses. The results further suggest that rainfall has generally gained an increasing importance for the generation of floods in Norway, while the role of snowmelt has been decreasing and the timing of snowmelt dominated floods has become earlier.

  1. Spatial and Temporal Variation in Primary Productivity (NDVI) of Coastal Alaskan Tundra: Decreased Vegetation Growth Following Earlier Snowmelt

    NASA Technical Reports Server (NTRS)

    Gamon, John A.; Huemmrich, K. Fred; Stone, Robert S.; Tweedie, Craig E.

    2015-01-01

    In the Arctic, earlier snowmelt and longer growing seasons due to warming have been hypothesized to increase vegetation productivity. Using the Normalized Difference Vegetation Index (NDVI) from both field and satellite measurements as an indicator of vegetation phenology and productivity, we monitored spatial and temporal patterns of vegetation growth for a coastal wet sedge tundra site near Barrow, Alaska over three growing seasons (2000-2002). Contrary to expectation, earlier snowmelt did not lead to increased productivity. Instead, productivity was associated primarily with precipitation and soil moisture, and secondarily with growing degree days, which, during this period, led to reduced growth in years with earlier snowmelt. Additional moisture effects on productivity and species distribution, operating over a longer time scale, were evident in spatial NDVI patterns associated with microtopography. Lower, wetter regions dominated by graminoids were more productive than higher, drier locations having a higher percentage of lichens and mosses, despite the earlier snowmelt at the more elevated sites. These results call into question the oft-stated hypothesis that earlier arctic growing seasons will lead to greater vegetation productivity. Rather, they agree with an emerging body of evidence from recent field studies indicating that early-season, local environmental conditions, notably moisture and temperature, are primary factors determining arctic vegetation productivity. For this coastal arctic site, early growing season conditions are strongly influenced by microtopography, hydrology, and regional sea ice dynamics, and may not be easily predicted from snowmelt date or seasonal average air temperatures alone. Our comparison of field to satellite NDVI also highlights the value of in-situ monitoring of actual vegetation responses using field optical sampling to obtain detailed information on surface conditions not possible from satellite observations alone.

  2. The Role of Dynamic Storage in the Response to Snowmelt Conditions in the Southwestern United States: Flux Hysteresis at the Catchment Scale

    NASA Astrophysics Data System (ADS)

    Driscoll, J. M.; Meixner, T.; Ferré, T. P. A.; Williams, M. W.; Sickman, J. O.; Molotch, N. P.; Jepsen, S. M.

    2014-12-01

    The role of dynamic storage in catchment discharge response to earlier snowmelt timing has not been fully quantified. Green Lake 4 (GL4) and Emerald Lake Watershed (ELW) have similar high-elevation settings but GL4 has greater estimated storage capacity relative to ELW due to differences in physical structure. Daily catchment area-normalized input (modelled snowmelt estimates) and output (measured discharge) in conjunction with mineral weathering products (hydrochemical data) for eleven snowmelt seasons from GL4 (more storage) and ELW (less storage) were used to determine the role of dynamic storage at the catchment scale. Daily fluxes generally show snowmelt is greater than discharge initially, changing mid-season to discharge being greater than snowmelt, creating a counter-clockwise hysteresis loop for each snowmelt season. This hysteresis loop can be approximated with a least-squares fitted ellipse. The properties of fitted ellipses were used to quantify catchment response, which were then compared between catchments with different storage capacities (GL4 and ELW). The eccentricity of the fitted ellipses can be used to quantify delay between snowmelt and discharge due to connection to subsurface storage; narrower loops show minimal storage delay whereas wider loops show greater storage delay. Variability of mineral weathering products shows changes in contribution from stored water over the snowmelt season. Both catchments show a moderate linear correlation between fitted ellipse area and total snowmelt volume (GL4 R2=0.516, ELW R2=0.614). Ellipse eccentricity is more consistent among years in ELW (range=0.81-0.94) than in GL4 (range=0.54-0.95), indicating a more consistent hydrologic structure and connectivity to shallow storage at ELW. The linear correlation between seasonal eccentricity versus snowmelt timing is stronger in ELW than GL4 (R2=0.741 and 0.223, respectively). ELW shows hydrochemical response independent of snowmelt timing, whereas GL4 shows more

  3. Availability of natural and regulated streamflows for instream uses during historical droughts, lower Neosho River, southeastern Kansas

    USGS Publications Warehouse

    Hart, R.J.; Stiles, T.C.

    1984-01-01

    The effects of three historical droughts on streamflows available for instream use on the lower Neosho River at Iola and Parsons, Kansas, were investigated. Natural streamflows that occurred during the three droughts were compared to the multiple-use and water-quality streamflows recommended by State agencies. A reservoir model was used to investigate the effects of John Redmond Reservoir on the natural streamflows. The regulated streamflow produced from the reservoir model then was compared to the multiple-use and water-quality streamflows. The regulated streamflows usually satisfied the multiple-use and water-quality streamflows more often than the natural streamflows. Frequency analysis made on the natural and regulated streamflows showed that the number of days of low flow (less than 30 cubic feet per second) were reduced by the regulated streamflows, which aided in the achievement of the multiple-use and water-quality streamflows goals. The reservoir model was used to determine if sufficient storage was available in John Redmond Reservoir to modify the natural streamflows in order to satisfy the multiple-use and water-quality streamflow recommendations. Additional storage of 15,400 acre-feet was estimated to be needed to maintain the multiple-use streamflows at Parsons. (USGS)

  4. A historical perspective on precipitation, drought severity, and streamflow in Texas during 1951-56 and 2011

    USGS Publications Warehouse

    Winters, Karl E.

    2013-01-01

    Annual mean streamflow and streamflow-duration curves for the 1951–56 and 2011 water years were assessed for 19 unregulated U.S. Geological Survey (USGS) streamflow-gaging stations. At eight of these streamflow-gaging stations, the annual mean streamflow was lower in 2011 than for any year during 1951–56; many of these stations are located in eastern Texas. Annual mean streamflows for streamflow-gaging stations in the Guadalupe, Blanco, and upper Frio River Basins were lower in 1956 than in 2011. The streamflow-duration curves for many streamflow-gaging stations indicate a lack of (or diminished) storm runoff during 2011. Low streamflows (those exceeded 90 to 95 percent of days) were lower for 1956 than for 2011 at seven streamflow-gaging stations. For most of these stations, the lowest of the low streamflows during 1951–56 occurred in 1956. During March to September 2011, record daily lows were measured at USGS streamflow-gaging station 08041500 Village Creek near Kountze, Tex., which has more than 70 years of record. Many other USGS streamflow-gaging stations in Texas started the 2011 water year with normal streamflow but by the end of the water year were flowing at near-record lows.

  5. Use of color maps and wavelet coherence to discern seasonal and interannual climate influences on streamflow variability in northern catchments

    NASA Astrophysics Data System (ADS)

    Carey, Sean K.; Tetzlaff, Doerthe; Buttle, Jim; Laudon, Hjalmar; McDonnell, Jeff; McGuire, Kevin; Seibert, Jan; Soulsby, Chris; Shanley, Jamie

    2013-10-01

    The higher midlatitudes of the northern hemisphere are particularly sensitive to change due to the important role the 0°C isotherm plays in the phase of precipitation and intermediate storage as snow. An international intercatchment comparison program called North-Watch seeks to improve our understanding of the sensitivity of northern catchments to change by examining their hydrological and biogeochemical variability and response. Here eight North-Watch catchments located in Sweden (Krycklan), Scotland (Girnock and Strontian), the United States (Sleepers River, Hubbard Brook, and HJ Andrews), and Canada (Dorset and Wolf Creek) with 10 continuous years of daily precipitation and runoff data were selected to assess daily to seasonal coupling of precipitation (P) and runoff (Q) using wavelet coherency, and to explore the patterns and scales of variability in streamflow using color maps. Wavelet coherency revealed that P and Q were decoupled in catchments with cold winters, yet were strongly coupled during and immediately following the spring snowmelt freshet. In all catchments, coupling at shorter time scales occurred during wet periods when the catchment was responsive and storage deficits were small. At longer time scales, coupling reflected coherence between seasonal cycles, being enhanced at sites with enhanced seasonality in P. Color maps were applied as an alternative method to identify patterns and scales of flow variability. Seasonal versus transient flow variability was identified along with the persistence of that variability on influencing the flow regime. While exploratory in nature, this intercomparison exercise highlights the importance of climate and the 0°C isotherm on the functioning of northern catchments.

  6. Numerical rivers: A synthetic streamflow generator for water resources vulnerability assessments

    NASA Astrophysics Data System (ADS)

    Borgomeo, Edoardo; Farmer, Christopher L.; Hall, Jim W.

    2015-07-01

    The vulnerability of water supplies to shortage depends on the complex interplay between streamflow variability and the management and demands of the water system. Assessments of water supply vulnerability to potential changes in streamflow require methods capable of generating a wide range of possible streamflow sequences. This paper presents a method to generate synthetic monthly streamflow sequences that reproduce the statistics of the historical record and that can express climate-induced changes in user-specified streamflow characteristics. The streamflow sequences are numerically simulated through random sampling from a parametric or a nonparametric distribution fitted to the historical data while shuffling the values in the time series until a sequence matching a set of desired temporal properties is generated. The desired properties are specified in an objective function which is optimized using simulated annealing. The properties in the objective function can be manipulated to generate streamflow sequences that exhibit climate-induced changes in streamflow characteristics such as interannual variability or persistence. The method is applied to monthly streamflow data from the Thames River at Kingston (UK) to generate sequences that reproduce historical streamflow statistics at the monthly and annual time scales and to generate perturbed synthetic sequences expressing changes in short-term persistence and interannual variability.

  7. Analysis of trends in selected streamflow statistics for the Concho River Basin, Texas, 1916-2009

    USGS Publications Warehouse

    Barbie, Dana L.; Wehmeyer, Loren L.; May, Jayne E.

    2012-01-01

    Six U.S. Geological Survey streamflow-gaging stations were selected for analysis. Streamflow-gaging station 08128000 South Concho River at Christoval has downward trends for annual maximum daily discharge and annual instantaneous peak discharge for the combined period 1931-95, 2002-9. Streamflow-gaging station 08128400 Middle Concho River above Tankersley has downward trends for annual maximum daily discharge and annual instantaneous peak discharge for the combined period 1962-95, 2002-9. Streamflow-gaging station 08128500 Middle Concho River near Tankersley has no significant trends in the streamflow statistics considered for the period 1931-60. Streamflow-gaging station 08134000 North Concho River near Carlsbad has downward trends for annual mean daily discharge, annual 7-day minimum daily discharge, annual maximum daily discharge, and annual instantaneous peak discharge for the period 1925-2009. Streamflow-gaging stations 08136000 Concho River at San Angelo and 08136500 Concho River at Paint Rock have downward trends for 1916-2009 for all streamflow statistics calculated, but streamflow-gaging station 08136000 Concho River at San Angelo has an upward trend for annual maximum daily discharge during 1964-2009. The downward trends detected during 1916-2009 for the Concho River at San Angelo are not unexpected because of three reservoirs impounding and profoundly regulating streamflow.

  8. Seasonal Patterns of Gastrointestinal Illness and Streamflow along the Ohio River

    PubMed Central

    Jagai, Jyotsna S.; Griffiths, Jeffrey K.; Kirshen, Paul K.; Webb, Patrick; Naumova, Elena N.

    2012-01-01

    Waterborne gastrointestinal (GI) illnesses demonstrate seasonal increases associated with water quality and meteorological characteristics. However, few studies have been conducted on the association of hydrological parameters, such as streamflow, and seasonality of GI illnesses. Streamflow is correlated with biological contamination and can be used as proxy for drinking water contamination. We compare seasonal patterns of GI illnesses in the elderly (65 years and older) along the Ohio River for a 14-year period (1991–2004) to seasonal patterns of streamflow. Focusing on six counties in close proximity to the river, we compiled weekly time series of hospitalizations for GI illnesses and streamflow data. Seasonal patterns were explored using Poisson annual harmonic regression with and without adjustment for streamflow. GI illnesses demonstrated significant seasonal patterns with peak timing preceding peak timing of streamflow for all six counties. Seasonal patterns of illness remain consistent after adjusting for streamflow. This study found that the time of peak GI illness precedes the peak of streamflow, suggesting either an indirect relationship or a more direct path whereby pathogens enter water supplies prior to the peak in streamflow. Such findings call for interdisciplinary research to better understand associations among streamflow, pathogen loading, and rates of gastrointestinal illnesses. PMID:22754472

  9. Influence of groundwater pumping on streamflow restoration following upstream dam removal

    USGS Publications Warehouse

    Constantz, J.; Essaid, H.

    2007-01-01

    We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watersbed streamflow comparisons were performed for several rivers flowing into the east side of the Central Valley, CA. Results suggest that, in the absence of upland dams supporting large reservoirs, some reaches of these rivers might develop ephemeral streamflow in late summer. As a quantitative analysis, we conducted a series of streamflow/ groundwater simulations (using MODFLOW-2000 plus the streamflow routing package, SFR1) for a representative hypothetical watershed, with an upland dam and groundwater pumping in the downstream basin, under humid, semi-arid, and and conditions. As a result of including the impact of groundwater pumping, post-dam removal simulated streamflow was significantly less than natural streamflow. The model predicts extensive ephemeral conditions in the basin during September for both the arid and semi-arid cases. The model predicts continued perennial conditions in the humid case, but spatially weighted, average streamflow of only 71% of natural September streamflow, as a result of continued pumping after dam removal.

  10. Isolating the impacts of land use and climate change on streamflow

    NASA Astrophysics Data System (ADS)

    Chawla, I.; Mujumdar, P. P.

    2015-08-01

    Quantifying the isolated and integrated impacts of land use (LU) and climate change on streamflow is challenging as well as crucial to optimally manage water resources in river basins. This paper presents a simple hydrologic modeling-based approach to segregate the impacts of land use and climate change on the streamflow of a river basin. The upper Ganga basin (UGB) in India is selected as the case study to carry out the analysis. Streamflow in the river basin is modeled using a calibrated variable infiltration capacity (VIC) hydrologic model. The approach involves development of three scenarios to understand the influence of land use and climate on streamflow. The first scenario assesses the sensitivity of streamflow to land use changes under invariant climate. The second scenario determines the change in streamflow due to change in climate assuming constant land use. The third scenario estimates the combined effect of changing land use and climate over the streamflow of the basin. Based on the results obtained from the three scenarios, quantification of isolated impacts of land use and climate change on streamflow is addressed. Future projections of climate are obtained from dynamically downscaled simulations of six general circulation models (GCMs) available from the Coordinated Regional Downscaling Experiment (CORDEX) project. Uncertainties associated with the GCMs and emission scenarios are quantified in the analysis. Results for the case study indicate that streamflow is highly sensitive to change in urban areas and moderately sensitive to change in cropland areas. However, variations in streamflow generally reproduce the variations in precipitation. The combined effect of land use and climate on streamflow is observed to be more pronounced compared to their individual impacts in the basin. It is observed from the isolated effects of land use and climate change that climate has a more dominant impact on streamflow in the region. The approach proposed in this

  11. Are South Texas Streamflow Variations Influenced by Sea Surface Temperature Changes in Pacific and Atlantic Oceans?

    NASA Astrophysics Data System (ADS)

    Murgulet, V.; Hay, R.; Ard, R.

    2013-12-01

    The impact of sea surface temperature (SST) anomalies of the Pacific and Atlantic Oceans on several major river basins in the continental U. S. has recently become well documented. Clear relationships have been identified between El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO) and continental U. S. streamflow. Because these relationships can be potentially used to predict streamflow variability, it would also be of great importance to evaluate whether these climate phenomena affect river basins at the sub-regional and/or local scale, objectives that are not usually addressed in previous studies. Therefore, this study is focused on the basin river system of South Texas, an area that encompasses approximately 30,000 km2 and is climatologically defined as subtropical subhumid. Streamflow data (1940-2011) from sixteen unimpaired U.S. Geological Survey gage stations were normalized into a South Texas streamflow data set and evaluated with respect to ENSO, PDO and AMO index time series. The comparison of South Texas annual streamflow with Pacific Decadal Oscillation and El Niño Southern Oscillation Indices shows that the warm phases of ENSO and PDO are generally associated with increased streamflow, whereas cold phases of ENSO and PDO result in lower streamflow volumes. In addition, cross-correlation analyses show a 7-8 month delayed streamflow response to sea surface temperature signals. Furthermore, annual streamflow variability in the South Texas river basins can be also due to sea surface temperature anomalies in the Atlantic Ocean. Higher streamflow values are shown during the cold phase of AMO, while relatively low streamflow values are illustrated during the warm phase of AMO. Thus, preliminary results show that SST anomalies in both Pacific and Atlantic Oceans influence the streamflow variability in the South Texas area. Current research is also focused on evaluating if these climate phenomena

  12. Preliminary assessment of streamflow characteristics for selected streams at Fort Gordon, Georgia, 1999-2000

    USGS Publications Warehouse

    Stamey, Timothy C.

    2001-01-01

    In 1999, the U.S. Geological Survey, in cooperation with the U.S. Army Signal Center and Fort Gordon, began collection of periodic streamflow data at four streams on the military base to assess and estimate streamflow characteristics of those streams for potential water-supply sources. Simple and reliable methods of determining streamflow characteristics of selected streams on the military base are needed for the initial implementation of the Fort Gordon Integrated Natural Resources Management Plan. Long-term streamflow data from the Butler Creek streamflow gaging station were used along with several concurrent discharge measurements made at three selected partial-record streamflow stations on Fort Gordon to determine selected low-flow streamflow characteristics. Streamflow data were collected and analyzed using standard U.S. Geological Survey methods and computer application programs to verify the use of simple drainage area to discharge ratios, which were used to estimate the low-flow characteristics for the selected streams. Low-flow data computed based on daily mean streamflow include: mean discharges for consecutive 1-, 3-, 7-, 14-, and 30-day period and low-flow estimates of 7Q10, 30Q2, 60Q2, and 90Q2 recurrence intervals. Flow-duration data also were determined for the 10-, 30-, 50-, 70-, and 90-percent exceedence flows. Preliminary analyses of the streamflow indicate that the flow duration and selected low-flow statistics for the selected streams averages from about 0.15 to 2.27 cubic feet per square mile. The long-term gaged streamflow data indicate that the streamflow conditions for the period analyzed were in the 50- to 90-percent flow range, or in which streamflow would be exceeded about 50 to 90 percent of the time.

  13. HYSEP: A Computer Program for Streamflow Hydrograph Separation and Analysis

    USGS Publications Warehouse

    Sloto, Ronald A.; Crouse, Michele Y.

    1996-01-01

    HYSEP is a computer program that can be used to separate a streamflow hydrograph into base-flow and surface-runoff components. The base-flow component has traditionally been associated with ground-water discharge and the surface-runoff component with precipitation that enters the stream as overland runoff. HYSEP includes three methods of hydrograph separation that are referred to in the literature as the fixed interval, sliding-interval, and local-minimum methods. The program also describes the frequency and duration of measured streamflow and computed base flow and surface runoff. Daily mean stream discharge is used as input to the program in either an American Standard Code for Information Interchange (ASCII) or binary format. Output from the program includes table,s graphs, and data files. Graphical output may be plotted on the computer screen or output to a printer, plotter, or metafile.

  14. Increasing influence of air temperature on upper Colorado River streamflow

    NASA Astrophysics Data System (ADS)

    Woodhouse, Connie A.; Pederson, Gregory T.; Morino, Kiyomi; McAfee, Stephanie A.; McCabe, Gregory J.

    2016-03-01

    This empirical study examines the influence of precipitation, temperature, and antecedent soil moisture on upper Colorado River basin (UCRB) water year streamflow over the past century. While cool season precipitation explains most of the variability in annual flows, temperature appears to be highly influential under certain conditions, with the role of antecedent fall soil moisture less clear. In both wet and dry years, when flow is substantially different than expected given precipitation, these factors can modulate the dominant precipitation influence on streamflow. Different combinations of temperature, precipitation, and soil moisture can result in flow deficits of similar magnitude, but recent droughts have been amplified by warmer temperatures that exacerbate the effects of relatively modest precipitation deficits. Since 1988, a marked increase in the frequency of warm years with lower flows than expected, given precipitation, suggests continued warming temperatures will be an increasingly important influence in reducing future UCRB water supplies.

  15. Increasing influence of air temperature on upper Colorado River streamflow

    USGS Publications Warehouse

    Woodhouse, Connie A.; Pederson, Gregory T.; Morino, Kiyomi; McAfee, Stephanie A.; McCabe, Gregory

    2016-01-01

    This empirical study examines the influence of precipitation, temperature, and antecedent soil moisture on upper Colorado River basin (UCRB) water year streamflow over the past century. While cool season precipitation explains most of the variability in annual flows, temperature appears to be highly influential under certain conditions, with the role of antecedent fall soil moisture less clear. In both wet and dry years, when flow is substantially different than expected given precipitation, these factors can modulate the dominant precipitation influence on streamflow. Different combinations of temperature, precipitation, and soil moisture can result in flow deficits of similar magnitude, but recent droughts have been amplified by warmer temperatures that exacerbate the effects of relatively modest precipitation deficits. Since 1988, a marked increase in the frequency of warm years with lower flows than expected, given precipitation, suggests continued warming temperatures will be an increasingly important influence in reducing future UCRB water supplies.

  16. Trends in streamflow of the San Pedro River, southeastern Arizona, and regional trends in precipitation and streamflow in southeastern Arizona and southwestern New Mexico

    USGS Publications Warehouse

    Thomas, Blakemore E.; Pool, Don R.

    2006-01-01

    This study was done to improve the understanding of trends in streamflow of the San Pedro River in southeastern Arizona. Annual streamflow of the river at Charleston, Arizona, has decreased by more than 50 percent during the 20th century. The San Pedro River is one of the few remaining free-flowing perennial streams in the arid Southwestern United States, and the riparian forest along the river supports several endangered species and is an important habitat for migratory birds. Trends in seasonal and annual precipitation and streamflow were evaluated for surrounding areas in southeastern Arizona and southwestern New Mexico to provide a regional perspective for the trends of the San Pedro River. Seasonal and annual streamflow trends and the relation between precipitation and streamflow in the San Pedro River Basin were evaluated to improve the understanding of the causes of trends. There were few significant trends in seasonal and annual precipitation or streamflow for the regional study area. Precipitation and streamflow records were analyzed for 11 time periods ranging from 1930 to 2002; no significant trends were found in 92 percent of the trend tests for precipitation, and no significant trends were found in 79 percent of the trend tests for streamflow. For the trends in precipitation that were significant, 90 percent were positive and most of those positive trends were in records of winter, spring, or annual precipitation that started during the mid-century drought in 1945-60. For the trends in streamflow that were significant, about half were positive and half were negative. Trends in precipitation in the San Pedro River Basin were similar to regional precipitation trends for spring and fall values and were different for summer and annual values. The largest difference was in annual precipitation, for which no trend tests were significant in the San Pedro River Basin, and 23 percent of the trend tests were significantly positive in the rest of the study area

  17. Complex network theory, streamflow, and hydrometric monitoring system design

    NASA Astrophysics Data System (ADS)

    Halverson, M. J.; Fleming, S. W.

    2015-07-01

    Network theory is applied to an array of streamflow gauges located in the Coast Mountains of British Columbia (BC) and Yukon, Canada. The goal of the analysis is to assess whether insights from this branch of mathematical graph theory can be meaningfully applied to hydrometric data, and, more specifically, whether it may help guide decisions concerning stream gauge placement so that the full complexity of the regional hydrology is efficiently captured. The streamflow data, when represented as a complex network, have a global clustering coefficient and average shortest path length consistent with small-world networks, which are a class of stable and efficient networks common in nature, but the observed degree distribution did not clearly indicate a scale-free network. Stability helps ensure that the network is robust to the loss of nodes; in the context of a streamflow network, stability is interpreted as insensitivity to station removal at random. Community structure is also evident in the streamflow network. A network theoretic community detection algorithm identified separate communities, each of which appears to be defined by the combination of its median seasonal flow regime (pluvial, nival, hybrid, or glacial, which in this region in turn mainly reflects basin elevation) and geographic proximity to other communities (reflecting shared or different daily meteorological forcing). Furthermore, betweenness analyses suggest a handful of key stations which serve as bridges between communities and might be highly valued. We propose that an idealized sampling network should sample high-betweenness stations, small-membership communities which are by definition rare or undersampled relative to other communities, and index stations having large numbers of intracommunity links, while retaining some degree of redundancy to maintain network robustness.

  18. Use and availability of continuous streamflow records in Tennessee

    USGS Publications Warehouse

    Lowery, J.F.

    1988-01-01

    This report documents the results of the data uses and funding part of a study of the cost-effectiveness of the streamflow information program in Tennessee. Presently, 88 continuous surface water gaging stations are operated in Tennessee on a budget of $490,800. Data uses and funding sources are identified for each of the 88 stations. Data from most stations have multiple uses. (USGS)

  19. Complex networks, streamflow, and hydrometric monitoring system design

    NASA Astrophysics Data System (ADS)

    Halverson, M.; Fleming, S.

    2014-12-01

    Network theory is applied to an array of streamflow gauges located in the Coast Mountains of British Columbia and Yukon, Canada. The goal of the analysis is to assess whether insights from this branch of mathematical graph theory can be meaningfully applied to hydrometric data, and more specifically, whether it may help guide decisions concerning stream gauge placement so that the full complexity of the regional hydrology is efficiently captured. The streamflow data, when represented as a complex network, has a global clustering coefficient and average shortest path length consistent with small-world networks, which are a class of stable and efficient networks common in nature, but the results did not clearly suggest a scale-free network. Stability helps ensure that the network is robust to the loss of nodes; in the context of a streamflow network, stability is interpreted as insensitivity to station removal at random. Community structure is also evident in the streamflow network. A community detection algorithm identified 10 separate communities, each of which appears to be defined by the combination of its median seasonal flow regime (pluvial, nival, hybrid, or glacial, which in this region in turn mainly reflects basin elevation) and geographic proximity to other communities (reflecting shared or different daily meteorological forcing). Betweenness analyses additionally suggest a handful of key stations which serve as bridges between communities and might therefore be highly valued. We propose that an idealized sampling network should sample high-betweenness stations, as well as small-membership communities which are by definition rare or undersampled relative to other communities, while retaining some degree of redundancy to maintain network robustness.

  20. Appraisal of streamflow in Tualatin River basin, Washington County, Oregon

    USGS Publications Warehouse

    Swift, C. H., III

    1971-01-01

    Data were derived by statistical methods and are adequate for general water-development planning. A duration hydrograph provides a general description of the within-year time distribution of streamflow. Generalized equations based on a sample of gaged flows are presented for estimating magnitude and frequency of flows at ungaged sites. Generalized storage relations are included for estimating storage requirements at gaged and ungaged sites.