Science.gov

Sample records for 180-day snowmelt streamflows

  1. Snowmelt rate dictates streamflow

    NASA Astrophysics Data System (ADS)

    Barnhart, Theodore B.; Molotch, Noah P.; Livneh, Ben; Harpold, Adrian A.; Knowles, John F.; Schneider, Dominik

    2016-08-01

    Declining mountain snowpack and earlier snowmelt across the western United States has implications for downstream communities. We present a possible mechanism linking snowmelt rate and streamflow generation using a gridded implementation of the Budyko framework. We computed an ensemble of Budyko streamflow anomalies (BSAs) using Variable Infiltration Capacity model-simulated evapotranspiration, potential evapotranspiration, and estimated precipitation at 1/16° resolution from 1950 to 2013. BSA was correlated with simulated baseflow efficiency (r2 = 0.64) and simulated snowmelt rate (r2 = 0.42). The strong correlation between snowmelt rate and baseflow efficiency (r2 = 0.73) links these relationships and supports a possible streamflow generation mechanism wherein greater snowmelt rates increase subsurface flow. Rapid snowmelt may thus bring the soil to field capacity, facilitating below-root zone percolation, streamflow, and a positive BSA. Previous works have shown that future increases in regional air temperature may lead to earlier, slower snowmelt and hence decreased streamflow production via the mechanism proposed by this work.

  2. 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 ...

  3. 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.

  4. Trends in snowmelt-related streamflow timing in the conterminous United States

    NASA Astrophysics Data System (ADS)

    Dudley, R. W.; Hodgkins, G. A.; McHale, M. R.; Kolian, M. J.; Renard, B.

    2017-04-01

    Changes in snowmelt-related streamflow timing have implications for water availability and use as well as ecologically relevant shifts in streamflow. Historical trends in snowmelt-related streamflow timing (winter-spring center volume date, WSCVD) were computed for minimally disturbed river basins in the conterminous United States. WSCVD was computed by summing daily streamflow for a seasonal window then calculating the day that half of the seasonal volume had flowed past the gage. We used basins where at least 30 percent of annual precipitation was received as snow, and streamflow data were restricted to regionally based winter-spring periods to focus the analyses on snowmelt-related streamflow. Trends over time in WSCVD at gages in the eastern U.S. were relatively homogenous in magnitude and direction and statistically significant; median WSCVD was earlier by 8.2 days (1.1 days/decade) and 8.6 days (1.6 days/decade) for 1940-2014 and 1960-2014 periods respectively. Fewer trends in the West were significant though most trends indicated earlier WSCVD over time. Trends at low-to-mid elevation (<1600 m) basins in the West, predominantly located in the Northwest, had median earlier WSCVD by 6.8 days (1940-2014, 0.9 days/decade) and 3.4 days (1960-2014, 0.6 days/decade). Streamflow timing at high-elevation (⩾1600 m) basins in the West had median earlier WSCVD by 4.0 days (1940-2014, 0.5 days/decade) and 5.2 days (1960-2014, 0.9 days/decade). Trends toward earlier WSCVD in the Northwest were not statistically significant, differing from previous studies that observed many large and (or) significant trends in this region. Much of this difference is likely due to the sensitivity of trend tests to the time period being tested, as well as differences in the streamflow timing metrics used among the studies. Mean February-May air temperature was significantly correlated with WSCVD at 100 percent of the study gages (field significant, p < 0.0001), demonstrating the

  5. 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...

  6. 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

  7. Predicting streamflows in snowmelt-driven watersheds using the flow duration curve method

    NASA Astrophysics Data System (ADS)

    Kim, D.; Kaluarachchi, J.

    2014-05-01

    Predicting streamflows in snow-fed watersheds in the Western United States is important for water allocation. Since many of these watersheds are heavily regulated through canal networks and reservoirs, predicting expected natural flows and therefore water availability under limited data is always a challenge. This study investigates the applicability of the flow duration curve (FDC) method for predicting natural flows in gauged and regulated snow-fed watersheds. Point snow observations, air temperature, precipitation, and snow water equivalent were used to simulate the snowmelt process with the SNOW-17 model, and extended to streamflow simulation using the FDC method with a modified current precipitation index. For regulated watersheds, a parametric regional FDC method was applied to reconstruct natural flow. For comparison, a simplified tank model was used considering both lumped and semi-distributed approaches. The proximity regionalization method was used to simulate streamflows in the regulated watersheds with the tank model. The results showed that the FDC method is capable of producing satisfactory natural flow estimates in gauged watersheds when high correlation exists between current precipitation index and streamflow. For regulated watersheds, the regional FDC method produced acceptable river diversion estimates, but it seemed to have more uncertainty due to less robustness of the FDC method. In spite of its simplicity, the FDC method is a practical approach with less computational burden for studies with minimal data availability.

  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. Predicting natural streamflows in regulated snowmelt-driven watersheds using regionalization methods

    NASA Astrophysics Data System (ADS)

    Kim, D.; Kaluarachchi, J.

    2013-07-01

    Predicting streamflows in snow-fed watersheds in the Western United States is important for water allocation. Since many of these watersheds are heavily regulated through canal networks and reservoirs, predicting expected natural flows and therefore water availability under limited data is always a challenge. This study investigates the applicability of the flow duration curve (FDC) method for predicting natural flows in gauged and ungauged snow-fed watersheds. Point snow observations, air temperature, precipitation, and snow water equivalent, are used to simulate snowmelt process with SNOW-17 model and extended to streamflow generation by a FDC method with modified current precipitation index. For regulated (ungauged) watersheds, a parametric regional FDC method is applied to reconstruct natural flow. For comparison, a simplified Tank Model is used as well. The proximity regionalization method is used to generate streamflow using the Tank Model in ungauged watersheds. The results show that the FDC method can produce acceptable natural flow estimates in both gauged and ungauged watersheds under data limited conditions. The performance of the FDC method is better in watersheds with relatively low evapotranspiration (ET). Multiple donor data sets including current precipitation index are recommended to reduce uncertainty of the regional FDC method for ungauged watersheds. In spite of its simplicity, the FDC method can perform better than the Tank Model under minimal data availability.

  10. 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.

  11. 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.

  12. 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

  13. Effect of geomorphic channel restoration on streamflow and groundwater in a snowmelt-dominated watershed

    NASA Astrophysics Data System (ADS)

    Tague, Christina; Valentine, Scott; Kotchen, Matthew

    2008-10-01

    Reengineering of stream channels is a common approach used to restore hydrologic function in degraded landscapes, but there has been little published research analyzing its effectiveness. A key challenge for impact assessment is disentangling the effects of restoration from climate variability. Trout Creek, near Lake Tahoe, California, was reengineered to reestablish hydrologic connectivity between the stream and its former floodplain. Gauges located above and below the site, along with groundwater well measurements, were used to analyze prerestoration and postrestoration hydrology. Results show that restoration has a seasonal impact with statistically significant increases in streamflow during the summer recession period and decreased groundwater table depths across a wide range of streamflow conditions. Paired gauges and statistical models that are robust to serial autocorrelation demonstrate a feasible approach for assessing hydrologic restoration in regions where climate patterns lead to substantial within-year and between-years variation in streamflow.

  14. 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.

  15. Prediction of snowmelt derived streamflow in a wetland dominated prairie basin

    NASA Astrophysics Data System (ADS)

    Fang, X.; Pomeroy, J. W.; Westbrook, C. J.; Guo, X.; Minke, A. G.; Brown, T.

    2010-02-01

    The eastern Canadian Prairies are dominated by cropland, pasture, woodland and wetland areas. The region is characterized by many poor and internal drainage systems and large amounts of surface water storage. Consequently, basins here have proven challenging to hydrological model predictions which assume good drainage to stream channels. The Cold Regions Hydrological Modelling platform (CRHM) is an assembly system that can be used to set up physically based, flexible, object oriented models. CRHM was used to create a prairie hydrological model for the externally drained Smith Creek Research Basin (~400 km2), east-central Saskatchewan. Physically based modules were sequentially linked in CRHM to simulate snow processes, frozen soils, variable contributing area and wetland storage and runoff generation. Five "representative basins" (RBs) were used and each was divided into seven hydrological response units (HRUs): fallow, stubble, grassland, river channel, open water, woodland, and wetland as derived from a supervised classification of SPOT 5 imagery. Two types of modelling approaches calibrated and uncalibrated, were set up for 2007/08 and 2008/09 simulation periods. For the calibrated modelling, only the surface depression capacity of upland area was calibrated in the 2007/08 simulation period by comparing simulated and observed hydrographs; while other model parameters and all parameters in the uncalibrated modelling were estimated from field observations of soils and vegetation cover, SPOT 5 imagery, and analysis of drainage network and wetland GIS datasets as well as topographic map based and LiDAR DEMs. All the parameters except for the initial soil properties and antecedent wetland storage were kept the same in the 2008/09 simulation period. The model performance in predicting snowpack, soil moisture and streamflow was evaluated and comparisons were made between the calibrated and uncalibrated modelling for both simulation periods. Calibrated and uncalibrated

  16. 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

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-22

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

  18. 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.

  19. 12 CFR 313.163 - Notification of debts of 180 days or less.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Notification of debts of 180 days or less. 313... Notification of debts of 180 days or less. The Director, in his discretion, may also notify the Secretary of the Treasury of debts that have been delinquent for 180 days or less, including debts the FDIC...

  20. 12 CFR 313.163 - Notification of debts of 180 days or less.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Notification of debts of 180 days or less. 313... Notification of debts of 180 days or less. The Director, in his discretion, may also notify the Secretary of the Treasury of debts that have been delinquent for 180 days or less, including debts the FDIC...

  1. 12 CFR 313.163 - Notification of debts of 180 days or less.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Notification of debts of 180 days or less. 313... Notification of debts of 180 days or less. The Director, in his discretion, may also notify the Secretary of the Treasury of debts that have been delinquent for 180 days or less, including debts the FDIC...

  2. 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... Payments § 24.401 Replacement housing payment for 180-day homeowner-occupants. (a) Eligibility. A displaced person is eligible for the replacement housing payment for a 180-day homeowner-occupant if the person:...

  3. 12 CFR 313.163 - Notification of debts of 180 days or less.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Notification of debts of 180 days or less. 313... Notification of debts of 180 days or less. The Director, in his discretion, may also notify the Secretary of the Treasury of debts that have been delinquent for 180 days or less, including debts the FDIC...

  4. 12 CFR 313.163 - Notification of debts of 180 days or less.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Notification of debts of 180 days or less. 313... Notification of debts of 180 days or less. The Director, in his discretion, may also notify the Secretary of the Treasury of debts that have been delinquent for 180 days or less, including debts the FDIC...

  5. 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.

  6. Slower snowmelt in a warmer world

    NASA Astrophysics Data System (ADS)

    Musselman, Keith N.; Clark, Martyn P.; Liu, Changhai; Ikeda, Kyoko; Rasmussen, Roy

    2017-02-01

    There is general consensus that projected warming will cause earlier snowmelt, but how snowmelt rates will respond to climate change is poorly known. We present snowpack observations from western North America illustrating that shallower snowpack melts earlier, and at lower rates, than deeper, later-lying snow-cover. The observations provide the context for a hypothesis of slower snowmelt in a warmer world. We test this hypothesis using climate model simulations for both a control time period and re-run with a future climate scenario, and find that the fraction of meltwater volume produced at high snowmelt rates is greatly reduced in a warmer climate. The reduction is caused by a contraction of the snowmelt season to a time of lower available energy, reducing by as much as 64% the snow-covered area exposed to energy sufficient to drive high snowmelt rates. These results have unresolved implications on soil moisture deficits, vegetation stress, and streamflow declines.

  7. 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

    ... 180-Day Extension of Compliance Date for Residential Furnaces and Boilers Test Procedure Amendments... amendments to the DOE test procedure for residential furnaces and boilers related to the standby mode and off... residential furnaces and boilers starting on October 15, 2011. FOR FURTHER INFORMATION CONTACT: Dr. Michael...

  8. 49 CFR 24.401 - Replacement housing payment for 180-day homeowner-occupants.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... displacement dwelling or the term of the new mortgage, whichever is shorter. (3) The interest rate on the new...) 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...

  9. 49 CFR 24.401 - Replacement housing payment for 180-day homeowner-occupants.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... displacement dwelling or the term of the new mortgage, whichever is shorter. (3) The interest rate on the new...) 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...

  10. 49 CFR 24.401 - Replacement housing payment for 180-day homeowner-occupants.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... displacement dwelling or the term of the new mortgage, whichever is shorter. (3) The interest rate on the new...) 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...

  11. 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 ...

  12. Relations between winter climatic variables and April streamflows in New England and implications for summer streamflows

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Dudley, Robert W.; Schalk, Luther F.

    2012-01-01

    A period of much below normal streamflow in southern New England during April 2012 raised concerns that a long-term period of drought could evolve through late spring and summer, leading to potential water availability issues. To understand better the relations between winter climatic variables and April streamflows, April streamflows from 31 streamflow gages in New England that drain relatively natural watersheds were tested for year-to-year correlation with winter precipitation and air temperature from nearby meteorological sites. Higher winter (December through March) precipitation is associated with higher April streamflows at many gages in northern and central New England. This implies that snowpack accumulation is an important mechanism for winter water storage and subsequently important for spring streamflows in this area. Higher March air temperatures are associated with lower April streamflows at many gages in central and southern New England, likely because the majority of snowmelt runoff occurs before April in warm years. A warm March 2012 contributed to early snowmelt runoff in New England and to much below normal April streamflows in southern New England. However, no strong relation was found between historical April streamflows and late-spring or summer streamflows in New England. The lack of a strong relation implies that summer precipitation, rather than spring conditions, controls summer streamflows.

  13. Modelling urban snowmelt runoff

    NASA Astrophysics Data System (ADS)

    Valeo, C.; Ho, C. L. I.

    2004-12-01

    Few investigations have been made into modelling snowmelt in urban areas; hence, current urban snowmelt routines have adopted parameters and approaches intended for rural areas that are not appropriate in an urban environment. This paper examines problems with current urban snowmelt models and proposes a model that uses parameters developed from field studies focusing exclusively on urban snow. The Urban Snow Model (USM) uses an energy balance scheme at an hourly time step, changes in urban snow albedo, and incorporates eight different types of redistributed snow cover. USM is tested against observed flow data from a small residential community located in Calgary, Alberta. The degree-day method for snowmelt, the SWMM model, and a modified version of USM that incorporates a partial energy budget scheme relying only on net radiation, are also tested against the observed flow data. The full energy budget version of USM outperformed all other models in terms of time to peak, peak flowrate and model efficiency; however, the modified version of USM fared quite well and is recommended when a lack of data exists. The degree-day method and the SWMM models fared poorly and were unable to simulate peak flowrates in most cases. The tests also demonstrated the need to distribute snow into appropriate snow covers in order to simulate peak flowrates accurately and provide good model efficiency.

  14. Effects of warming on groundwater flow in mountainous snowmelt-dominated catchments

    NASA Astrophysics Data System (ADS)

    Evans, S. G.; Ge, S.; Molotch, N. P.

    2015-12-01

    In mountainous regions, warmer air temperatures have led to an earlier onset of spring snowmelt and lower snowmelt rates; i.e. because snowmelt has shifted earlier when energy availability is lower. These changes to snowmelt will likely affect the partitioning of snowmelt water between surface runoff and groundwater flow, and therefore, the lag time between snowmelt and streamflow. While the connection between snowmelt and surface runoff has been well-studied, the impact of snowmelt variability on groundwater flow processes has received limited attention, especially in mountainous catchments. We construct a two-dimensional, finite element, coupled flow and heat transport hydrogeologic model to evaluate how changes in snowmelt onset and rate may alter groundwater discharge to streams in mountainous catchments. The coupled hydrogeologic model simulates seasonally frozen ground by incorporating permeability variation as a function of temperature and allows for modeling of pore water freeze and thaw. We apply the model to the Green Lakes Valley (GLV) watershed in the Rocky Mountains of Colorado, a representative snowmelt-dominated catchment. Snowmelt for the GLV catchment is reconstructed from a 12 year (1996-2007) dataset of hydrometeorological records and satellite-derived snow covered area. Modeling results suggest that on a yearly cycle, groundwater infiltration and discharge is limited by the seasonally frozen subsurface. Under average conditions from 1996 to 2007, maximum groundwater discharge to the surface lags maximum snowmelt by approximately two months. Ongoing modeling is exploring how increasing air temperatures affect lag times between snowmelt and groundwater discharge to streams. This study has implications for water resource availability and its temporal variability in a warming global climate.

  15. 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...

  16. The importance of snowmelt spatiotemporal variability for isotope-based hydrograph separation in a high-elevation catchment

    NASA Astrophysics Data System (ADS)

    Schmieder, Jan; Hanzer, Florian; Marke, Thomas; Garvelmann, Jakob; Warscher, Michael; Kunstmann, Harald; Strasser, Ulrich

    2016-12-01

    Seasonal snow cover is an important temporary water storage in high-elevation regions. Especially in remote areas, the available data are often insufficient to accurately quantify snowmelt contributions to streamflow. The limited knowledge about the spatiotemporal variability of the snowmelt isotopic composition, as well as pronounced spatial variation in snowmelt rates, leads to high uncertainties in applying the isotope-based hydrograph separation method. The stable isotopic signatures of snowmelt water samples collected during two spring 2014 snowmelt events at a north- and a south-facing slope were volume weighted with snowmelt rates derived from a distributed physics-based snow model in order to transfer the measured plot-scale isotopic composition of snowmelt to the catchment scale. The observed δ18O values and modeled snowmelt rates showed distinct inter- and intra-event variations, as well as marked differences between north- and south-facing slopes. Accounting for these differences, two-component isotopic hydrograph separation revealed snowmelt contributions to streamflow of 35 ± 3 and 75 ± 14 % for the early and peak melt season, respectively. These values differed from those determined by formerly used weighting methods (e.g., using observed plot-scale melt rates) or considering either the north- or south-facing slope by up to 5 and 15 %, respectively.

  17. 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...

  18. 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.

  19. August streamflow

    NASA Astrophysics Data System (ADS)

    Streamflows varied across the country during August, with record low flows reported in New York and on the Columbia River at the Dalles, Oreg., while record high flows were reported in Alabama, Kansas, and North Dakota, according to the end of the month check on water resources conditions by the U.S. Geological Survey (USGS). USGS hydrologists said that a nationwide tally of the 171 streamflow gaging stations that reported during August showed that 25% (43 stations) recorded flows in the above-normal range, 59% (101 stations) had flows in the normal range, and 16% (27 stations) recorded flows in the below-normal range.

  20. 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.

  1. 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.

  2. 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).

  3. Extended healing validation of an artificial tendon to connect the quadriceps muscle to the Tibia: 180-day study.

    PubMed

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

    2012-07-01

    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 non-living 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 contralateral unoperated control legs at 180 days. Maximum forces in the operated leg (vs. unoperated) were 1,400 ± 93 N (vs. 1,179 ± 61 N), linear stiffnesses were 33 ± 3 N/mm (vs. 37 ± 4 N/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 orthopedic oncology, revision arthroplasty, tendon transfer, and tendon injury reconstruction.

  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. 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 homeowner displaced from a mobile home, and/or from the acquired mobile home site. 24.502 Section 24.502... ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  6. 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 homeowner displaced from a mobile home, and/or from the acquired mobile home site. 24.502 Section 24.502... ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  7. 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 homeowner displaced from a mobile home, and/or from the acquired mobile home site. 24.502 Section 24.502... ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  8. 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 homeowner displaced from a mobile home, and/or from the acquired mobile home site. 24.502 Section 24.502... ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  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 homeowner displaced from a mobile home, and/or from the acquired mobile home site. 24.502 Section 24.502... ACQUISITION FOR FEDERAL AND FEDERALLY-ASSISTED PROGRAMS Mobile Homes § 24.502 Replacement housing payment...

  10. What Drives Changes in the Timing of Snowmelt Runoff in the Western United States?

    NASA Astrophysics Data System (ADS)

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

    2001-12-01

    Future climate-change scenarios forecast widespread reductions in snowpack accumulation and resulting declines in snowmelt-derived streamflow in many mountainous watersheds around the world. These predicted changes could have important consequences for water resources supply and management by changing flood regimes and the seasonal availability of water resources in ways that current structures and policies may not be able to accommodate. The western United States, where precipitation and runoff are strongly seasonal, represent a very important laboratory for studying the impact of climatic changes on streamflow timing and water resources, as well as offering opportunities for identifying the immediate causes of such changes. It is a matter of considerable concern, then, that regionally coherent trends towards an earlier start of the snowmelt runoff season has been identified in the near-natural flow series of rivers throughout the western United States. The advance in the timing of the spring snowmelt pulse is associated with decreased April-July (AMJJ) fractional flows, and increasing fractions of the annual runoff occurring earlier in the water year, especially in March. Most of these trends began in the late 1940s and have continued through the 1990's. They are present in snowmelt-dominated streams throughout the western United States, except for an area in the southern Rocky Mountains/southwest. In order to clarify the patterns of year-to-year as well as trending changes in streamflow timing principal component analyses (PCAs) were carried out on three measures: (a) the day of onset of the spring snowmelt runoff pulses in each river, (b) the AMJJ fractional flows, and (c) the March fractional flows. The PCAs identify broad regions of common variability in the changes of streamflow timing by all three measures. The two regions that most consistently vary together in terms of the magnitude of trends and the redistribution of streamflow are the Sierra Nevada

  11. 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....

  12. 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...

  13. 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.

  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. Organic contaminant amplification during snowmelt.

    PubMed

    Meyer, Torsten; Wania, Frank

    2008-04-01

    The release of organic contaminants from melting snow poses risks to aquatic and terrestrial organisms and to humans who rely on drinking water and food production from regions that are seasonally snow-covered. Measured and model-predicted spring peak concentrations in waters receiving snowmelt motivate a thorough investigation of organic contaminant behaviour during melting. On the basis of the current understanding of snow metamorphosis, snowmelt hydrology and chemical partitioning in snow, this critical review aims to provide a qualitative picture of the processes involved in the release of organic contaminants from a melting snowpack. The elution sequence of organic substances during snowmelt is strongly dependent on their environmental partitioning properties and the physical properties of the snowpack. Water-soluble organic contaminants can be discharged in greatly elevated concentrations at an early stage of melting, while the bulk of the hydrophobic chemicals attached to particles is often released at the end of the melt period. Melting of a highly metamorphosed and deep snowpack promotes such shock load releases, whereas a shallow snow cover over a relatively warm ground experiencing irregular melting over the winter season is unlikely to generate notable peak releases of organic substances. Meltwater runoff over frozen ground directly transfers contaminant shock loads into receiving water bodies, while permeable soils buffer and dilute the contaminants. A more quantitative understanding of the behaviour of organic contaminants in varying snowmelt scenarios will depend on controlled laboratory studies combined with field investigations. Reliable numerical process descriptions will need to be developed to integrate water quality and contaminant fate models.

  16. Hydrometeorological model for streamflow prediction

    USGS Publications Warehouse

    Tangborn, Wendell V.

    1979-01-01

    The hydrometeorological model described in this manual was developed to predict seasonal streamflow from water in storage in a basin using streamflow and precipitation data. The model, as described, applies specifically to the Skokomish, Nisqually, and Cowlitz Rivers, in Washington State, and more generally to streams in other regions that derive seasonal runoff from melting snow. Thus the techniques demonstrated for these three drainage basins can be used as a guide for applying this method to other streams. Input to the computer program consists of daily averages of gaged runoff of these streams, and daily values of precipitation collected at Longmire, Kid Valley, and Cushman Dam. Predictions are based on estimates of the absolute storage of water, predominately as snow: storage is approximately equal to basin precipitation less observed runoff. A pre-forecast test season is used to revise the storage estimate and improve the prediction accuracy. To obtain maximum prediction accuracy for operational applications with this model , a systematic evaluation of several hydrologic and meteorologic variables is first necessary. Six input options to the computer program that control prediction accuracy are developed and demonstrated. Predictions of streamflow can be made at any time and for any length of season, although accuracy is usually poor for early-season predictions (before December 1) or for short seasons (less than 15 days). The coefficient of prediction (CP), the chief measure of accuracy used in this manual, approaches zero during the late autumn and early winter seasons and reaches a maximum of about 0.85 during the spring snowmelt season. (Kosco-USGS)

  17. Modeling streamflow response from Minnesota peatlands

    SciTech Connect

    Guertin, D.P.

    1984-01-01

    To aid in the development of Minnesota's 7 million acres of peatlands, and to evaluate the hydrologic impacts and reclamation options associated with such development, a Peatland Hydrologic Impact Model (PHIM) was devised. PHIM is a deterministic, continuous simulation model designed to simulate streamflow resulting from rainfall and snowmelt under both natural and altered (mined) conditions. It is largely physically based and requires watershed information and hydrometeorological data that are usually available in an operational setting. PHIM can provide both daily and hourly estimates of streamflow, PHIM consists of 5 submodels, 3 land type submodels for natural peatlands, mined peatlands and mineral soil uplands and 2 routing submodels for channel reaches and reservoirs. Streamflow from headwater peatland watersheds can be simulated by combining the submodels in the order that best describes the basin. The model was tested on the basis of stormflow events form a 3758 ha undisturbed peatland and a 155 ha peatland that had undergone ditching and peat mining for horticultural purposes. Simulated streamflow volumes averaged 86 and 91% of observed volumes for the undisturbed and mined area, respectively. Peat discharges were simulated within 84 and 65% of observed values, respectively.

  18. Mercury on the move during snowmelt in Vermont

    NASA Astrophysics Data System (ADS)

    Shanley, James B.; Schuster, Paul F.; Reddy, Michael M.; Roth, David A.; Taylor, Howard E.; Aiken, George R.

    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.

  19. 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.

  20. 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

  1. Riparian zone flowpath dynamics during snowmelt in a small headwater catchment

    USGS Publications Warehouse

    McGlynn, B.L.; McDonnell, Jeffery J.; Shanley, J.B.; Kendall, C.

    1999-01-01

    The hydrology of the near-stream riparian zone in upland humid catchments is poorly understood. We examined the spatial and temporal aspects of riparian flowpaths during snowmelt in a headwater catchment within the Sleepers River catchment in northern Vermont. A transect of 15 piezometers was sampled for Ca, Si, DOC, other major cations, and ??18O. Daily piezometric head values reflected variations in the stream hydrograph induced by melt and rainfall. The riparian zone exhibited strong upward discharge gradients. An impeding layer was identified between the till and surficial organic soil. Water solute concentrations increased toward the stream throughout the melt. Ca concentrations increased with depth and DOC concentrations decreased with depth. The concentrations of Ca in all piezometers were lower during active snowmelt than during post-melt low flow. Ca data suggest snowmelt infiltration to depth; however, only upslope piezometers exhibited snowmelt infiltration and consequent low ??18O values, while ??18O values varied less than 0.5% in the deep riparian piezometers throughout the study period. Ca and ??18O values in upslope piezometers during low streamflow were comparable to Ca and ??18O in riparian piezometers during high streamflow. The upland water Ca and ??18O may explain the deep riparian Ca dilution and consistent ??18O composition. The temporal pattern in Ca and ??18O indicate that upland water moves to the stream via a lateral displacement mechanism that is enhanced by the presence of distinct soil/textural layers. Snowmelt thus initiates the flux of pre-melt, low Ca upland water to depth in the riparian zone, but itself does not appear at depth in the riparian zone during spring melt. This is despite the coincident response of upland groundwater and stream discharge.The hydrology of the near-stream riparian zone in upland humid catchments is poorly understood. We examined the spatial and temporal aspects of riparian flowpaths during snowmelt in a

  2. 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.

  3. Streamflow data: Chapter 13

    USGS Publications Warehouse

    Wiche, Gregg J.; Holmes, Robert

    2016-01-01

    Streamflow data are vital for a variety of water-resources issues, from flood warning to water supply planning. The collection of streamflow data is usually an involved and complicated process. This chapter serves as an overview of the streamflow data collection process. Readers with the need for the detailed information on the streamflow data collection process are referred to the many references noted in this chapter.

  4. 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.

  5. 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.

  6. 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.

    PubMed

    Whittaker, Margaret H; Wang, Gensheng; Chen, Xue-Qing; 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.

  7. Accounting for Vegetation Effects in Spatially Distributed Snowmelt Modeling

    NASA Astrophysics Data System (ADS)

    Garen, D. C.; Marks, D.

    2004-05-01

    The effects of vegetation on snowpack energy dynamics can be highly significant and must be taken into account when simulating snowmelt. This becomes challenging, however, for spatially distributed models covering large areas such as river basins. In this case, processes occurring at the scale of individual trees or bushes must be parameterized and upscaled to the size of the model's grid cells, which could range from 10 up to a few hundred meters. An application of a spatially distributed energy balance snowmelt model to the Boise River basin in Idaho, USA has required the development of algorithms to account for the effects of vegetation (especially forest) on the climate input data to the model. This particularly affects the solar and thermal radiation input to the snowpack, including not only the direct effects of the vegetation but also the effect of vegetation debris on the snow albedo. Vegetation effects on vertical profiles of wind speed and temperature could not be considered due to limited measurements, and only a crude estimate of wind speed differences between forested and nonforested grid cells was used. The simulated snow fields were verified using point snow water equivalent and snow depth data as well as satellite images of snow covered area. Although good results were obtained in these comparisons, each of these methods has limitations, in that point measurements are not necessarily representative of a grid cell, and satellite images have a coarse resolution and cannot detect snow under trees. Another test was to use the simulated snowmelt fields as input to a spatially distributed water balance and streamflow simulation model, which indicated that the volume and timing of snowmelt input to the basin were accurately represented. A limitation of the modeling method used is that the models are run independently in sequence, the output of one being stored and becoming the input of the next. This means that there is no opportunity for feedbacks between

  8. Individuals with neurological diseases are at increased risk of fractures within 180 days of admission to long-term care in Ontario

    PubMed Central

    Jantzi, Micaela; Maher, Amy C.; Ioannidis, George; Hirdes, John P.; Giangregorio, Lora M.; Papaioannou, Alexandra

    2016-01-01

    Background individuals residing in long-term care (LTC) are more likely to have a fragility fracture than community-dwelling seniors. The purpose of this study was to determine whether the presence of neurological diseases was associated with an increased risk of fracture within 180 days of admission to LTC. Methods this retrospective cohort study used data collected in the LTC setting using the Resident Assessment Instrument (RAI) 2.0 during the period from 2006 to 2011 (N = 42,089). Multivariable logistic regression analyses were conducted to determine the associations between the presence of neurological conditions and incident fractures, with and without adjustment for clinical variables. Results the incident fracture rate for all LTC residents was 2.6% (N = 1,094). Neurological condition group size ranged from n = 21,015 for Alzheimer’s disease or related dementias (ADRD) to n = 21 for muscular dystrophy (MD). The incidence of fracture among residents with specific neurological diseases was as follows: ADRD, 3.2% (n = 672), MD, 4.8% (n = 1), Parkinson’s disease, 2.5% (n = 57), stroke, 2.3% (n = 166), epilepsy, 2.5% (n = 38), Huntington’s disease, 1.4% (n = 1), multiple sclerosis, 0.3% (n = 1) and traumatic brain injury, 3.8% (n = 11); among the comparison group with no neurological conditions, the fracture rate was 2.0% (n = 366). The neurological diseases that were associated with a significantly greater odds of having an incident fracture in the first 180 days of LTC admission were as follows: ADRD (1.3; 95% CI: 1.1–1.5), epilepsy (1.5; 95% CI: 1.0–2.1) and traumatic brain injury (2.7; 95% CI: 1.4–5.0). Conclusion LTC residents with ADRD, epilepsy and traumatic brain injury are at a higher risk for sustaining an incident fracture in the first 180 days of admission and should be considered for fracture prevention strategies. PMID:25398885

  9. Spatial patterns of March and September streamflow trends in Pacific Northwest Streams, 1958-2008

    USGS Publications Warehouse

    Chang, Heejun; Jung, Il-Won; Steele, Madeline; Gannett, Marshall

    2012-01-01

    . Consequently, a better understanding of the relationships among summer streamflow, precipitation, snowmelt, elevation, and geology can help water managers predict the response of regional summer streamflow to global warming.

  10. 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.

  11. 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.

  12. From Snow to Flow: Predicting the Timing of Peak Streamflow Using SNOTEL Ablation Curves

    NASA Astrophysics Data System (ADS)

    Ferguson, K. J.; McNamara, J. P.; Abramovich, R.

    2014-12-01

    It is well understood that there exists a relationship between mountainous snowpack and seasonal streamflow. For snow-dominated river basins within the western United States, ~ 80% of streamflow is a result of seasonal snowmelt. In Idaho, where a significant amount of winter precipitation is stored as snowpack, predictions for the timing and magnitude of peak streamflow are essential for many water users, including water resource and irrigation managers. Of particular interest is the relationship between the timing of snowmelt and the timing of peak streamflow. While agencies such as the Natural Resources Conservation Service (NRCS) are tasked with the responsibility of providing water supply forecasts, few methods have used a data-driven, empirical modeling approach to investigate relationships between ablation timing monitored by the NRCS SNOTEL program and streamflow monitored by the United States Geological Survey (USGS). Such analyses could provide predictive tools that allow water users and managers to easily access and interpret information about peak streamflow. Idaho hosts over 80 SNOTEL sites that report hydrometeorological data, and 213 streamflow gauging stations. The goal of this study is to establish relationships between the timing of ablation at SNOTEL stations and peak streamflow within select basins in Idaho, and to synthesize results into user-friendly visualization tools that will provide estimates of the probability that peak streamflow will occur within a certain number of days as ablation progresses from 0 to 100%. In our initial test basin, the Boise River basin, we evaluated melt-out levels in increments of 10% from three SNOTEL sites located in the basin and produced cumulative density function (CDF) curves to illustrate the probability of peak streamflow occurring within a given number of days from the date at which the SNOTEL site reached each melt-out level.

  13. 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

  14. Changes in Snowmelt Runoff Timing: Potential Implications for Stream Temperature and Native Salmonid Habitat

    NASA Astrophysics Data System (ADS)

    MacDonald, R.; Boon, S.; Byrne, J. M.; Silins, U.

    2013-12-01

    Atmospheric warming is expected to maintain the trend towards an earlier onset of spring snowmelt across western North America in the future. An advanced spring streamflow peak has important implications for aquatic ecosystems, particularly cold-water salmonids that are sensitive to changes in stream hydrological and thermal regimes. We tested stream temperature sensitivity to atmospheric warming scenarios in a headwater catchment on the eastern slopes of the Rocky Mountains by applying a process-based hydrometeorological and stream temperature model. We used a field study in three thermally and hydrologically distinct catchments to provide context for modelling. Results indicate that stream temperature sensitivity to atmospheric warming is variable and corresponds with changes in streamflow. Predictions of lower spring, higher summer and fall, and lower winter stream temperatures are consistent with field study results. This analysis suggests the thermal habitat of native salmonids could become less suitable under future climatic conditions, favouring non-native species.

  15. Snowmelt discharge characteristics Sierra Nevada, California

    USGS Publications Warehouse

    Peterson, David; Smith, Richard; Stewart, Iris; Knowles, Noah; Soulard, Chris; Hager, Stephen

    2005-01-01

    Alpine snow is an important water resource in California and the western U.S. Three major features of alpine snowmelt are the spring pulse (the first surge in snowmelt-driven river discharge in spring), maximum snowmelt discharge, and base flow (low river discharge supported by groundwater in fall). A long term data set of hydrologic measurements at 24 gage locations in 20 watersheds in the Sierra Nevada was investigated to relate patterns of snowmelt with stream discharge In wet years, the daily variations in snowmelt discharge at all the gage locations in the Sierra Nevada correlate strongly with the centrally located Merced River at Happy Isles, Yosemite National Park (i.e., in 1983, the mean of the 23 correlations was R= 0.93 + 0.09) ; in dry years, however, this correlation breaks down (i.e., in year 1977, R=0.72 + 0.24). A general trend towards earlier snowmelt was found and modeled using correlations with the timing of the spring pulse and the river discharge center of mass. For the 24 river and creek gage locations in this study, the spring pulse appeared to be a more sensitive measure of early snowmelt than the center of mass. The amplitude of maximum daily snowmelt discharge correlates strongly with initial snow water equivalent. Geologic factors, base rock permeability and soil-to-bedrock ratio, influence snowmelt flow pathways. Although both surface and ground water flows and water levels increase in wet years compared to dry years, the increase was greater for surface water in a watershed with relatively impermeable base rock than for surface water in a watershed with highly permeable base rock The relation was the opposite for base flow (ground water). The increase was greater for groundwater in a watershed with permeable rock compared to ground water in a watershed with impermeable rock. A similar, but weaker, surface/groundwater partitioning was observed in relatively impermeable granitic watersheds with differing soil-to-bedrock ratios. The

  16. 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)

  17. 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 ...

  18. 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.)

  19. Consequences of early snowmelt in Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-01-01

    Snow melted significantly earlier in the Rocky Mountains in 2012 than in previous years, with serious consequences for plants and animals, scientists reported at the AGU Fall Meeting. David Inouye of the University of Maryland, College Park, and the Rocky Mountain Biological Laboratory said that "the timing of winter's end is changing." He has been observing snowmelt dates and flowering of plants at a site at 2900 meters altitude. This year's snowmelt occurred 23 April, whereas the previous year, snow melted 19 June, he reported.

  20. 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

  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. Snowmelt pollutant removal in bioretention areas.

    PubMed

    Muthanna, Tone Merete; Viklander, Maria; Blecken, Godecke; Thorolfsson, Sveinn T

    2007-10-01

    Snow accumulating in urban areas and alongside roads can accumulate high pollutant loads and the subsequent snowmelt can produce high pollutant loads in receiving waters. This paper examines the treatment of roadside snowmelt in bioretention with respect to pollutant removal, pollutant pathways, and major sinks. Bioretention was used to treat snowmelt from three types of urban roads in Trondheim, Norway: residential, medium, and roads with high-density traffic. Metal retention in bioretention boxes had a mass reduction in zinc, copper, lead, and cadmium in the range of 89-99%, and a decrease in outflow concentrations in the range 81-99%. Cadmium was only measured in the water samples, while the other three metals were traced through the system to identify the main sinks. The top mulch layer was the largest sink for the retained metals, with up to 74% of the zinc retained in this mulch layer. The plant metal uptakes were only 2-8% of the total metal retention; however, the plants still play an important role with respect to root zone development and regeneration, which fosters infiltration and reduces the outflow load. Dissolved pollutants in snowmelt tend to be removed with the first flush of meltwater, creating an enrichment ratio with respect to the average pollutant concentrations in the snow. The effect of this enrichment ratio was examined through the bioretention system, and found to be less predominant than that typically reported for untreated snowmelt. The enrichment factors were in the range of 0.65-1.51 for the studied metals.

  4. 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.

  5. Spatially distributed energy balance snowmelt modelling in a mountainous river basin: estimation of meteorological inputs and verification of model results

    NASA Astrophysics Data System (ADS)

    Garen, David C.; Marks, Danny

    2005-12-01

    A spatially distributed energy balance snowmelt model has been applied to a 2150 km 2 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 time series of meteorological input data were obtained using various spatial interpolation and simulation methods. The variables include precipitation, air temperature, dew point temperature, wind speed, and solar and thermal radiation. The goal was to use readily available data and relatively straightforward, yet physically meaningful, methods to develop the spatial fields. With these meteorological fields as input, the simulated fields of snow water equivalent, snow depth, and snow covered area reproduce observations very well. The simulated snowmelt fields are also used as input to a spatially distributed hydrologic model to estimate streamflow. This gives an additional verification of the snowmelt modelling results as well as provides a linkage of the two models to generate hydrographs for water management information. This project is a demonstration of spatially distributed energy balance snowmelt modelling in a large mountainous catchment using data from existing meteorological networks. This capability then suggests the potential for developing new spatial hydrologic informational products and the possibility of improving the accuracy of the prediction of hydrologic processes for water and natural resources management.

  6. Towards a tracer-based conceptualization of meltwater dynamics and streamflow response in a glacierized catchment

    NASA Astrophysics Data System (ADS)

    Penna, Daniele; Engel, Michael; Bertoldi, Giacomo; Comiti, Francesco

    2017-01-01

    Multiple water sources and the physiographic heterogeneity of glacierized catchments hamper a complete conceptualization of runoff response to meltwater dynamics. In this study, we used environmental tracers (stable isotopes of water and electrical conductivity) to obtain new insight into the hydrology of glacierized catchments, using the Saldur River catchment, Italian Alps, as a pilot site. We analysed the controls on the spatial and temporal patterns of the tracer signature in the main stream, its selected tributaries, shallow groundwater, snowmelt and glacier melt over a 3-year period. We found that stream water electrical conductivity and isotopic composition showed consistent patterns in snowmelt-dominated periods, whereas the streamflow contribution of glacier melt altered the correlations between the two tracers. By applying two- and three-component mixing models, we quantified the seasonally variable proportion of groundwater, snowmelt and glacier melt at different locations along the stream. We provided four model scenarios based on different tracer signatures of the end-members; the highest contributions of snowmelt to streamflow occurred in late spring-early summer and ranged between 70 and 79 %, according to different scenarios, whereas the largest inputs by glacier melt were observed in mid-summer, and ranged between 57 and 69 %. In addition to the identification of the main sources of uncertainty, we demonstrated how a careful sampling design is critical in order to avoid underestimation of the meltwater component in streamflow. The results of this study supported the development of a conceptual model of streamflow response to meltwater dynamics in the Saldur catchment, which is likely valid for other glacierized catchments worldwide.

  7. 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

  8. 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

  9. 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

  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.; 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

  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.; 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

  12. Precipitation-Runoff Simulations of Current and Natural Streamflow Conditions in the Methow River Basin, Washington

    USGS Publications Warehouse

    Ely, D. Matthew

    2003-01-01

    Management of the water resources of the Methow River Basin is changing in response to the listing of three species of fish under the Endangered Species Act and the Washington State-legislated watershed-planning process. This report describes the construction and calibration of an enhanced precipitation-runoff model for the Methow River Basin and evaluates the model as a predictive tool for assessing the current and natural streamflow conditions. This study builds upon a previous precipitation-runoff model for the Methow River Basin and validates the current model using a new, more extensive streamflow data network. The major enhancement was the simulation of current flow conditions with the addition of irrigation diversions, returns, and application. The Geographic Information System Weasel characterized the physical properties of the basin and the Modular Modeling System, using the Precipitation-Runoff Modeling System, simulated the hydrologic flow. Streamflow was simulated for water years 1992-2001 to calibrate the model to measured streamflows. A sensitivity analysis was completed using nonlinear regression to determine hydrologic parameters pertinent to the modeling results. Simulated and measured streamflow generally showed close agreement, especially during spring runoff from snowmelt. Low-flow or baseflow periods, most restrictive to fish habitation, were simulated reasonably well yet possessed the most uncertainty. Simulations of annual mean streamflow as a percentage of measured annual mean streamflow for the 10-year calibration period at six of the seven streamflow-gaging stations ranged from -35.2 to +26.2 percent, with 65 percent of the simulated values within 15 percent. One station was intentionally calibrated to over-simulate discharge (simulated discharge greater than measured discharge) in order to compensate for observed channel losses not simulated by the model. Simulation of water years 1960-2001 demonstrated great variability in monthly

  13. A Hybrid Architecture of Neural Networks for Daily Streamflow Forecasting

    NASA Astrophysics Data System (ADS)

    Moradkhani, H.

    2001-12-01

    Streamflow forecasting has always been a challenging task for water resources engineers and managers and the major component of water resources system control. For years numerous techniques have been suggested and employed for streamflow forecasting. Computational Neural Networks (NNs), which are capable of recognizing hidden patterns in data, have recently become popular in many hydrologic applications. In this study, hybrid NN is developed for one step ahead forecasting of daily streamflow. Radial Basis Function (RBF) composed of a group of Gausian functions is used in conjunction with Self-Organizing Feature Map (SOFM) used in data classification. RBF transfers those classified input variables into the desired output estimate. Eight years of daily rainfall, streamflow, and temperature in Salt River basin were used for calibration and validation. Since 60%-80% of the water supply produced by the basin comes in the form of snow, further consideration of the existing time delay of snow melting process in the basin to the watershed outlet is important. Therefore two separated settings were considered in this simulation: the first one only includes several short-term daily rainfall and streamflow in the input sequence; the second setting, on the other hand, includes a longer time period (three-months) of temperature data sequence. Various statistical analyses, such as root mean square error, bias estimate, noise to signal ratio, and correlation coefficients of estimates and observations, were done to evaluate the forecast models. The preliminary results show that the accuracy of the model once considering the long-term effect of the snowmelt is conspicuous with respect to short-term effect. The effectiveness of the proposed and current operational models is evaluated.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. Climate change impacts on streamflow and subbasin-scale hydrology in the Upper Colorado River Basin.

    PubMed

    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 21(st) 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 21(st) 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

  20. 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.

  1. Streamflow record extension for selected streams in the Susitna River Basin, Alaska

    USGS Publications Warehouse

    Curran, Janet H.

    2012-01-01

    Daily streamflow records for water years 1950–2010 in the Susitna River Basin range in length from 4 to 57 years, and many are distributed within that period in a way that might not adequately represent long-term streamflow conditions. Streamflow in the basin is affected by the Pacific Decadal Oscillation (PDO), a multi-decadal climate pattern that shifted from a cool phase to a warm phase in 1976. Records for many streamgages in the basin fell mostly within one phase of the PDO, such that monthly and annual statistics from observed records might not reflect streamflow conditions over a longer period. Correlations between daily discharge values sufficed for extending streamflow records at 11 of the 14 streamgages in the basin on the basis of relatively long-term records for one or more of the streamgages within the basin, or one outside the basin, that were defined as index stations. Streamflow at the index stations was hydrologically responsive to glacier melt and snowmelt, and correlated well with flow from similar high-elevation, glaciated basins, but flow in low-elevation basins without glaciers could not be correlated to flow at any of the index stations. Kendall-Theil Robust Line multi-segment regression equations developed for one or more index stations were used to extend daily discharge values to the full 61-year period for all 11 streamgages. Monthly and annual statistics prepared for the extended records show shifts in timing of breakup and freeze-up and magnitude of snowmelt peaks largely predicted by the PDO phase.

  2. 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.

  3. 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.

  4. 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.

  5. How snowpack heterogeneity affects diurnal streamflow timing

    USGS Publications Warehouse

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

    2005-01-01

    Diurnal cycles of streamflow in snow-fed rivers can be used to infer the average time a water parcel spends in transit from the top of the snowpack to a stream gauge in the river channel. This travel time, which is measured as the difference between the hour of peak snowmelt in the afternoon and the hour of maximum discharge each day, ranges from a few hours to almost a full day later. Travel times increase with longer percolation times through deeper snowpacks, and prior studies of small basins have related the timing of a stream's diurnal peak to the amount of snow stored in a basin. However, in many larger basins the time of peak flow is nearly constant during the first half of the melt season, with little or no variation between years. This apparent self-organization at larger scales can be reproduced by employing heterogeneous observations of snow depths and melt rates in a model that couples porous medium flow through an evolving snowpack with free surface flow in a channel. Copyright 2005 by the American Geophysical Union.

  6. Snowmelt Processes At High Altitude. How Does A Partly Frozen Ground Affect Alpine Aquifer During Snowmelt?

    NASA Astrophysics Data System (ADS)

    Bayard, D.; Stähli, M.; Turberg, P.; Parriaux, A.

    In alpine areas, the snow cover plays an important role as water reservoir, especially at high altitudes (over 2000 meters). Water is stored as snow over the winter and re- leased in spring, recharging mountain aquifers through infiltration. These aquifers are essential, especially for the supply of human activities with water during dry seasons. But these snow reservoirs may produce severe flooding, in particular when snowmelt is combined with heavy rainfall and a frozen underground. Surface frost can drastically reduce water infiltration by several orders of magnitude and therefore affect groundwater recharge. Evaluating the impact of frost on snowmelt runoff at selected sites in the Alps enables us to quantify water exportation processes (i.e. surface runoff, subsurface runoff and deep percolation) from the snow pack. The main objectives of this research project consisted (a) in studying the different pro- cesses influencing groundwater recharge during snowmelt periods, i.e. snow cover evolution, ground frost depth, snowmelt water runoff types on specific sites, (b) in as- sessing the variability of frost formation while taking into account spatial, altitudinal and climatic differences, (c) in identifying meteorological situations that are critical with respect to flooding. Two experimental sites were selected in the southern Swiss Alps, one at Hannigalp (2100 m) and the other at the Gd St-Bernard pass (2500 m). The Hannigalp site is characterized by a rather dry (600 mm/year) and wind free climate, whereas high amounts of precipitation (2100 mm/year) and strong winds are encountered at the Grand St Bernard. To investigate the delay in snowmelt due to the orientation and altitude, two secondary sites were additionally chosen near the Gd St-Bernard pass. In spite of a very thick snow pack, water balance measurements of winter 2000/01 showed for Grächen null to very low surface and subsurface flow due to the fact that soil frost was local. At the Gd St Bernard

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

    USGS Publications Warehouse

    Huntington, Justin L.; Niswonger, Richard G.

    2012-01-01

    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

  8. 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.

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

    NASA Astrophysics Data System (ADS)

    Kormos, Patrick R.; Luce, Charles H.; Wenger, Seth J.; Berghuijs, Wouter R.

    2016-07-01

    Path analyses of 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 temperature changes have important implications for adaptation planning because global circulation models produce relatively robust estimates of air temperature changes but have large uncertainties in projected precipitation amounts in the Pacific Northwest U.S. Quantile regression analyses indicate that low streamflow extremes from the majority of catchments in this study have declined from 1948 to 2013, which may significantly affect terrestrial and aquatic ecosystems, and water resource management. Trends in the 25th percentile of mean annual streamflow have declined and the center of timing has occurred earlier. We quantify the relative influences of total precipitation and air temperature on the annual low streamflow extremes from 42 stream gauges using mean annual streamflow as a proxy for precipitation amount effects and streamflow center of timing as a proxy for temperature effects on low flow metrics, including 7q10 summer (the minimum 7 day flow during summer with a 10 year return period), mean August, mean September, mean summer, 7q10 winter, and mean winter flow metrics. These methods have the benefit of using only readily available streamflow data, which makes our results robust against systematic errors in high elevation distributed precipitation data. Winter low flow metrics are weakly tied to both mean annual streamflow and center of timing.

  10. Earlier snowmelt reduces atmospheric carbon uptake in midlatitude subalpine forests

    NASA Astrophysics Data System (ADS)

    Winchell, Taylor S.; Barnard, David M.; Monson, Russell K.; Burns, Sean P.; Molotch, Noah P.

    2016-08-01

    Previous work demonstrates conflicting evidence regarding the influence of snowmelt timing on forest net ecosystem exchange (NEE). Based on 15 years of eddy covariance measurements in Colorado, years with earlier snowmelt exhibited less net carbon uptake during the snow ablation period, which is a period of high potential for productivity. Earlier snowmelt aligned with colder periods of the seasonal air temperature cycle relative to later snowmelt. We found that the colder ablation-period air temperatures during these early snowmelt years lead to reduced rates of daily NEE. Hence, earlier snowmelt associated with climate warming, counterintuitively, leads to colder atmospheric temperatures during the snow ablation period and concomitantly reduced rates of net carbon uptake. Using a multilinear-regression (R2 = 0.79, P < 0.001) relating snow ablation period mean air temperature and peak snow water equivalent (SWE) to ablation-period NEE, we predict that earlier snowmelt and decreased SWE may cause a 45% reduction in midcentury ablation-period net carbon uptake.

  11. Seasonal and spatial patterns in diurnal cycles in streamflow in the western United States

    USGS Publications Warehouse

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

    2002-01-01

    The diurnal cycle in streamflow constitutes a significant part of the variability in many rivers in the western United States and can be used to understand some of the dominant processes affecting the water balance of a given river basin. Rivers in which water is added diurnally, as in snowmelt, and rivers in which water is removed diurnally, as in evapotranspiration and infiltration, exhibit substantial differences in the timing, relative magnitude, and shape of their diurnal flow variations. Snowmelt-dominated rivers achieve their highest sustained flow and largest diurnal fluctuations during the spring melt season. These fluctuations are characterized by sharp rises and gradual declines in discharge each day. In large snowmelt-dominated basins, at the end of the melt season, the hour of maximum discharge shifts to later in the day as the snow line retreats to higher elevations. Many evapotranspiration/infiltration-dominated rivers in the western states achieve their highest sustained flows during the winter rainy season but exhibit their strongest diurnal cycles during summer months, when discharge is low, and the diurnal fluctuations compose a large percentage of the total flow. In contrast to snowmelt-dominated rivers, the maximum discharge in evapotranspiration/infiltration-dominated rivers occurs consistently in the morning throughout the summer. In these rivers, diurnal changes are characterized by a gradual rise and sharp decline each day.

  12. 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

  13. 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.

  14. United States streamflow probabilities based on forecasted La Nina, winter-spring 2000

    USGS Publications Warehouse

    Dettinger, M.D.; Cayan, D.R.; Redmond, K.T.

    1999-01-01

    Although for the last 5 months the TahitiDarwin Southern Oscillation Index (SOI) has hovered close to normal, the “equatorial” SOI has remained in the La Niña category and predictions are calling for La Niña conditions this winter. In view of these predictions of continuing La Niña and as a direct extension of previous studies of the relations between El NiñoSouthern Oscil-lation (ENSO) conditions and streamflow in the United States (e.g., Redmond and Koch, 1991; Cayan and Webb, 1992; Redmond and Cayan, 1994; Dettinger et al., 1998; Garen, 1998; Cayan et al., 1999; Dettinger et al., in press), the probabilities that United States streamflows from December 1999 through July 2000 will be in upper and lower thirds (terciles) of the historical records are estimated here. The processes that link ENSO to North American streamflow are discussed in detail in these diagnostics studies. Our justification for generating this forecast is threefold: (1) Cayan et al. (1999) recently have shown that ENSO influences on streamflow variations and extremes are proportionately larger than the corresponding precipitation teleconnections. (2) Redmond and Cayan (1994) and Dettinger et al. (in press) also have shown that the low-frequency evolution of ENSO conditions support long-lead correlations between ENSO and streamflow in many rivers of the conterminous United States. (3) In many rivers, significant (weeks-to-months) delays between precipitation and the release to streams of snowmelt or ground-water discharge can support even longer term forecasts of streamflow than is possible for precipitation. The relatively slow, orderly evolution of El Niño-Southern Oscillation episodes, the accentuated dependence of streamflow upon ENSO, and the long lags between precipitation and flow encourage us to provide the following analysis as a simple prediction of this year’s river flows.

  15. 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.

  16. 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.

  17. Klamath Falls downtown development geothermal sidewalk snowmelt

    SciTech Connect

    Brown, B.

    1995-10-01

    The Klamuth Falls, Oregon, downtown has seen a period of decline over the past 20 years as businesses have moved to new suburban shopping centers. Downtown business owners and the Klamuth Falls Downtown Redevelopment Agency are working to reverse that trend with a Downtown Streetscape Project intended to make the downtown a more pleasant place to work and do business. The visible elements of the project include new crosswalks with brick pavers, wheelchair ramps at sidewalk corners, new concrete sidewalks with a consistent decorative grid pattern, sidewalk planters for trees and flowers, and antique-style park benches and lighting fixtures. A less visible, but equally valuable feature of the project is the plastic tubing installed under the sidewalks, wheelchair ramps and crosswalks, designed to keep them snow and ice free in the winter. A unique feature of the snowmelt system is the use of geothermal heated water on the return side of the Klamath Falls Geothermal District Heating System, made possible by the recent expansion of the district heating system.

  18. 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.

  19. 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

  20. An assessment of streamflow vulnerability to climate using ...

    EPA Pesticide Factsheets

    Identifying regions with similar hydrology is useful for assessing water quality and quantity across the U.S., especially areas that are difficult or costly to monitor. For example, hydrologic landscapes (HLs) have been used to map streamflow variability and assess the spatial distribution of climatic response in Oregon, Alaska, and the Pacific Northwest. HLs have also been applied to assess historic and projected climatic impacts across the Western U.S. In this project, we summarized (1) the HL classification methodology and (2) the utility of using HLs as a tool to classify the vulnerability of streams to climatic changes in the Western U.S. During the HL classification process, we analyzed climate, seasonality, aquifer permeability, terrain, and soil permeability as the primary hydrologic drivers (and precipitation intensity as a secondary driver) associated with large scale hydrologic processes (storage, conveyance, and flow of water into or out of the watershed) in the West. We derived the dominant hydrologic pathways (surface runoff or deep or shallow groundwater) from the HL classification of different catchments to test our hypotheses: 1) Changes in climate will have greater impacts on streamflow in catchments dominated by surface runoff. 2) Catchments historically fed by surface runoff from winter snowmelt in the spring will experience greater impact if precipitation falls as rain instead of snow. We calculated S* (precipitation surplus, which includes

  1. 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

  2. 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.

  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. 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

  5. Nonparametric Streamflow Disaggregation Model

    NASA Astrophysics Data System (ADS)

    Lee, T.; Salas, J. D.; Prairie, J. R.

    2009-05-01

    Stochastic streamflow generation is generally utilized for planning and management of water resources systems. For this purpose a number of parametric and nonparametric modeling alternatives have been suggested in literature. Among them temporal and spatial disaggregation approaches play an important role particularly to make sure that historical variance-covariance properties are preserved at various temporal and spatial scales. In this paper, we review the underlying features of nonparametric disaggregation, identify some of their pros and cons, and propose a disaggregation algorithm that is capable of surmounting some of the shortcoming of the current models. The proposed models hinge on k-nearest neighbor resampling, the accurate adjusting procedure, and a genetic algorithm. The model has been tested and compared to an existing nonparametric disaggregation approach using data of the Colorado River system. It has been shown that the model is capable of (i) reproducing the season-to-season correlations including the correlation between the last season of the previous year and the first season of the current year, (ii) minimizing or avoiding the generation of flow patterns across the year that are literally the same as those of the historical records, and (iii) minimizing or avoiding the generation of negative flows. In addition, it is applicable to intermittent river regimes. Suggestions for further improving the model are discussed.

  6. 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

  7. A streamflow assimilation system for ensemble streamflow forecast over France

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    SAFRAN-ISBA-MODCOU (SIM) is a hydro-meteorological model used at Météo-France to predict soil water content and river streamflows. In order to produce a better initial state for the Ensemble Streamflow forecasts, an assimilation system is developed at Météo-France. This system uses past streamflow measurements in order to assess the best initial state of soil water content of the model for streamflow prediction. The data assimilation system is developed with a modular software (PALM, from the Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique), and is based on the Best Linear Unbiased Estimator method. Data from a maximum of 186 gauge stations are assimilated over France. This first study focuses on the selection of the best model variables for the assimilation process : root zone layer only or root and sub root layers taken together or apart. Two versions of SIM, including or not an exponential profile of hydraulic conductivity in the soil, are tested, and a set of classical hydrologic scores will be performed in order to describe the performances of the experiments. The impact of this improvement of the initial state of the model on ensemble streamflow forecasts scores will be assessed in a subsequent work.

  8. 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

  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. Reducing streamflow forecast uncertainty: Application and qualitative assessment of the upper klamath river Basin, Oregon

    USGS Publications Warehouse

    Hay, L.E.; McCabe, G.J.; Clark, M.P.; Risley, J.C.

    2009-01-01

    The accuracy of streamflow forecasts depends on the uncertainty associated with future weather and the accuracy of the hydrologic model that is used to produce the forecasts. We present a method for streamflow forecasting where hydrologic model parameters are selected based on the climate state. Parameter sets for a hydrologic model are conditioned on an atmospheric pressure index defined using mean November through February (NDJF) 700-hectoPascal geopotential heights over northwestern North America [Pressure Index from Geopotential heights (PIG)]. The hydrologic model is applied in the Sprague River basin (SRB), a snowmelt-dominated basin located in the Upper Klamath basin in Oregon. In the SRB, the majority of streamflow occurs during March through May (MAM). Water years (WYs) 1980-2004 were divided into three groups based on their respective PIG values (high, medium, and low PIG). Low (high) PIG years tend to have higher (lower) than average MAM streamflow. Four parameter sets were calibrated for the SRB, each using a different set of WYs. The initial set used WYs 1995-2004 and the remaining three used WYs defined as high-, medium-, and low-PIG years. Two sets of March, April, and May streamflow volume forecasts were made using Ensemble Streamflow Prediction (ESP). The first set of ESP simulations used the initial parameter set. Because the PIG is defined using NDJF pressure heights, forecasts starting in March can be made using the PIG parameter set that corresponds with the year being forecasted. The second set of ESP simulations used the parameter set associated with the given PIG year. Comparison of the ESP sets indicates that more accuracy and less variability in volume forecasts may be possible when the ESP is conditioned using the PIG. This is especially true during the high-PIG years (low-flow years). ?? 2009 American Water Resources Association.

  12. 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

  13. Trends in precipitation and streamflow and changes in stream morphology in the Fountain Creek watershed, Colorado, 1939-99

    USGS Publications Warehouse

    Stogner, Robert W.

    2000-01-01

    The Fountain Creek watershed, located in and along the eastern slope of the Front Range section of the southern Rocky Mountains, drains approximately 930 square miles of parts of Teller, El Paso, and Pueblo Counties in eastern Colorado. Streamflow in the watershed is dominated by spring snowmelt runoff and storm runoff during the summer monsoon season. Flooding during the 1990?s has resulted in increased streambank erosion. Property loss and damage associated with flooding and bank erosion has cost area residents, businesses, utilities, municipalities, and State and Federal agencies millions of dollars. Precipitation (4 stations) and streamflow (6 stations) data, aerial photographs, and channel reconnaissance were used to evaluate trends in precipitation and streamflow and changes in channel morphology. Trends were evaluated for pre-1977, post-1976, and period-of-record time periods. Analysis revealed the lack of trend in total annual and seasonal precipitation during the pre-1977 time period. In general, the analysis also revealed the lack of trend in seasonal precipitation for all except the spring season during the post-1976 time period. Trend analysis revealed a significant upward trend in long-term (period of record) total annual and spring precipitation data, apparently due to a change in total annual precipitation throughout the Fountain Creek watershed. During the pre-1977 time period, precipitation was generally below average; during the post- 1976 time period, total annual precipitation was generally above average. During the post- 1976 time period, an upward trend in total annual and spring precipitation was indicated at two stations. Because two of four stations evaluated had upward trends for the post-1976 period and storms that produce the most precipitation are isolated convection storms, it is plausible that other parts of the watershed had upward precipitation trends that could affect trends in streamflow. Also, because of the isolated nature of

  14. 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.

  15. 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

  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. 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.

  18. 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

  19. 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

  20. 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.

  1. Understanding the variations in the timing of daily streamflow peak during melt season

    NASA Astrophysics Data System (ADS)

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

    2015-12-01

    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 snowpack or percolation, 2) surface and subsurface flow of melt from the base of snowpacks to streams, and 3) translation of water flux in the streams to streamgage stations. The goal of this study is to evaluate and quantify how these processes affect observed DPT variations at the Reynolds Mountain East (RME) research catchment in southwest Idaho, USA. To accomplish this goal, DPT was simulated for the RME catchment over a period of 25 water years using a modified snowmelt model, iSnobal, and a hydrology model, PIHM. The influence of each controlling process was then evaluated by simulating the DPT with and without the process under consideration. Both intra- and inter-seasonal variability in DPT were evaluated. Results indicate that the average DPT is dominantly influenced by subsurface flow, whereas the seasonal variations in DPT are primarily controlled by percolation through snow. In addition to the three processes previously identified in the literature, processes governing the time for ripening of the snowpack are identified as additionally influencing DPT variability. Results also indicate that the relative dominance of each control varies through the melt season, and between wet and dry years. The results could be used for supporting DPT prediction efforts and for prioritization of observables for DPT determination.

  2. Biological consequences of earlier snowmelt from desert dust deposition in alpine landscapes

    PubMed Central

    Steltzer, Heidi; Landry, Chris; Painter, Thomas H.; Anderson, Justin; Ayres, Edward

    2009-01-01

    Dust deposition to mountain snow cover, which has increased since the late 19th century, accelerates the rate of snowmelt by increasing the solar radiation absorbed by the snowpack. Snowmelt occurs earlier, but is decoupled from seasonal warming. Climate warming advances the timing of snowmelt and early season phenological events (e.g., the onset of greening and flowering); however, earlier snowmelt without warmer temperatures may have a different effect on phenology. Here, we report the results of a set of snowmelt manipulations in which radiation-absorbing fabric and the addition and removal of dust from the surface of the snowpack advanced or delayed snowmelt in the alpine tundra. These changes in the timing of snowmelt were superimposed on a system where the timing of snowmelt varies with topography and has been affected by increased dust loading. At the community level, phenology exhibited a threshold response to the timing of snowmelt. Greening and flowering were delayed before seasonal warming, after which there was a linear relationship between the date of snowmelt and the timing of phenological events. Consequently, the effects of earlier snowmelt on phenology differed in relation to topography, which resulted in increasing synchronicity in phenology across the alpine landscape with increasingly earlier snowmelt. The consequences of earlier snowmelt from increased dust deposition differ from climate warming and include delayed phenology, leading to synchronized growth and flowering across the landscape and the opportunity for altered species interactions, landscape-scale gene flow via pollination, and nutrient cycling. PMID:19564599

  3. Biological consequences of earlier snowmelt from desert dust deposition in alpine landscapes.

    PubMed

    Steltzer, Heidi; Landry, Chris; Painter, Thomas H; Anderson, Justin; Ayres, Edward

    2009-07-14

    Dust deposition to mountain snow cover, which has increased since the late 19(th) century, accelerates the rate of snowmelt by increasing the solar radiation absorbed by the snowpack. Snowmelt occurs earlier, but is decoupled from seasonal warming. Climate warming advances the timing of snowmelt and early season phenological events (e.g., the onset of greening and flowering); however, earlier snowmelt without warmer temperatures may have a different effect on phenology. Here, we report the results of a set of snowmelt manipulations in which radiation-absorbing fabric and the addition and removal of dust from the surface of the snowpack advanced or delayed snowmelt in the alpine tundra. These changes in the timing of snowmelt were superimposed on a system where the timing of snowmelt varies with topography and has been affected by increased dust loading. At the community level, phenology exhibited a threshold response to the timing of snowmelt. Greening and flowering were delayed before seasonal warming, after which there was a linear relationship between the date of snowmelt and the timing of phenological events. Consequently, the effects of earlier snowmelt on phenology differed in relation to topography, which resulted in increasing synchronicity in phenology across the alpine landscape with increasingly earlier snowmelt. The consequences of earlier snowmelt from increased dust deposition differ from climate warming and include delayed phenology, leading to synchronized growth and flowering across the landscape and the opportunity for altered species interactions, landscape-scale gene flow via pollination, and nutrient cycling.

  4. 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

  5. Development of a precipitation-runoff model to simulate unregulated streamflow in the South Fork Flathead River Basin, Montana

    USGS Publications Warehouse

    Chase, K.J.

    2011-01-01

    percent higher than observed for the test period. Downstream from the reservoir, simulated mean annual streamflow was 17 percent lower than observed streamflow for the calibration period and 12 percent lower than observed streamflow for the test period. Simulated mean April-July streamflow downstream from the reservoir was 13 percent lower than observed streamflow for the calibration period and 6 percent lower than observed streamflow for the test period. Calibrating to solar radiation, potential evapotranspiration, and snow-covered area improved the model representation of evapotranspiration, snow accumulation, and snowmelt processes. Simulated basin mean monthly solar radiation values for both the calibration and test periods were within 9 percent of observed values except during the month of December (28 percent different). Simulated basin potential evapotranspiration values for both the calibration and test periods were within 10 percent of observed values except during the months of January (100 percent different) and February (13 percent different). The larger percent errors in simulated potential evaporation occurred in the winter months when observed potential evapotranspiration values were very small; in January the observed value was 0.000 inches and in February the observed value was 0.009 inches. Simulated start of melting of the snowpack occurred at about the same time as observed start of melting. The simulated snowpack accumulated to 90-100 percent snow-covered area 1 to 3 months earlier than observed snowpack. This overestimated snowpack during the winter corresponded to underestimated streamflow during the same period. In addition to the primary-parameter file, four other parameter files were created: for a "recent" period (1991-2005), a historical period (1967-90), a "wet" period (1989-97), and a "dry" period (1998-2005). For each data file of projected precipitation and air temperature, a single parameter file can be used to simulate a s

  6. 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.

  7. 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.

  8. Ground water occurrence and contributions to streamflow in an alpine catchment, Colorado Front Range

    USGS Publications Warehouse

    Clow, D.W.; Schrott, L.; Webb, R.; Campbell, D.H.; Torizzo, A.O.; Dornblaser, M.

    2003-01-01

    Ground water occurrence, movement, and its contribution to streamflow were investigated in Loch Vale, an alpine catchment in the Front Range of the Colorado Rocky Mountains. Hydrogeomorphologic mapping, seismic refraction measurements, and porosity and permeability estimates indicate that talus slopes are the primary ground water reservoir, with a maximum storage capacity that is equal to, or greater than, total annual discharge from the basin (5.4 ± 0.8 × 106 m3). Although snowmelt and glacial melt provide the majority of annual water flux to the basin, tracer tests and gauging along a stream transect indicate that ground water flowing from talus can account for ≥75% of streamflow during storms and the winter base flow period. The discharge response of talus springs to storms and snowmelt reflects rapid transmittal of water through coarse debris at the talus surface and slower release of water from finer-grained sediments at depth.Ice stored in permafrost (including rock glaciers) is the second largest ground water reservoir in Loch Vale; it represents a significant, but seldom recognized, ground water reservoir in alpine terrain. Mean annual air temperatures are sufficiently cold to support permafrost above 3460 m; however, air temperatures have increased 1.1° to 1.4°C since the early 1990s, consistent with long-term (1976–2000) increases in air temperature measured at other high-elevation sites in the Front Range, European Alps, and Peruvian Andes. If other climatic factors remain constant, the increase in air temperatures at Loch Vale is sufficient to increase the lower elevational limit of permafrost by 150 to 190 m. Although this could cause a short-term increase in streamflow, it may ultimately result in decreased flow in the future.

  9. 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

  10. Executive summary - Assessing the response of Emerald Lake, an alpine watershed in Sequoia National Park, California, to acidification during snowmelt using a simple hydrochemical model

    SciTech Connect

    Hooper, R.P.; West, C.T.; Peters, N.E. )

    1990-01-01

    A simple process-oriented model, called the Alpine Lake Forecaster (ALF), was constructed using data collected from the Integrated Watershed Study of Emerald Lake, Sequoia National Park, California. ALF is able to capture the basic solute patterns during snowmelt in this alpine catchment where groundwater is a minor contributor to streamflow. It includes an empirical representation of primary mineral weathering as the only alkalinity generating mechanism. During a heavy snow year, such as the one used for calibrating the model, the model accurately simulated the surface water chemical change in response to the initial ionic pulse from the snowpack and to the dilution that occurs at peak snowmelt. Because the model does not consider cation exchange, it over-predicts the acidification during the initial period of snowmelt, and therefore is a conservative predictor. However, the minimum alkalinity observed in the main inflows to Emerald Lake and in the lake outflow is accurately simulated by the model. The representation of the lake as simply a missing volume with no additional chemical reactions is supported by the observation. The model predicts a change of 2 to 5 microequiv/L in the minimum alkalinity of the lake outflow during snowmelt if the deposition would have to increase between two and 18 times the current load-alkalinity of the lake; the precise increase depends on hydrologic conditions and on the pattern of solute release from the snowpack. An acidic rainstorm that exhausted the alkalinity of the lake was observed during summer 1984 after the lake had stratified, and is the likely cause of the acidification of Emerald Lake.

  11. 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.

  12. DEBRIS FLOWS AND HYPERCONCENTRATED STREAMFLOWS.

    USGS Publications Warehouse

    Wieczorek, Gerald F.

    1986-01-01

    Examination of recent debris-flow and hyperconcentrated-streamflow events in the western United States reveals (1) the topographic, geologic, hydrologic, and vegetative conditions that affect initiation of debris flows and (2) the wide ranging climatic conditions that can trigger debris flows. Recognition of these physiographic and climatic conditions has aided development of preliminary methods for hazard evaluation. Recent developments in the application of electronic data gathering, transmitting, and processing systems shows potential for real-time hazard warning.

  13. 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.

  14. Use of a precipitation-runoff model to simulate natural streamflow conditions in the Methow River basin, Washington

    USGS Publications Warehouse

    Ely, David Matthew; Risley, John C.

    2001-01-01

    Management of the water resources of the Methow River Basin is changing in response to the listing of three species of fish under the Endangered Species Act and the Washington State-legislated watershed-planning process. Management options must be considered that minimize adverse effects on people but meet instream flow needs for fish. This report describes the construction and calibration of the Methow River Basin watershed model and evaluates the accuracy of the model as a predictive tool for assessing the natural instream flow conditions. The term ?natural? instream flow is stressed because surface water within the Basin is used for agricultural irrigation through an extensive system of diversions. The USGS Modular Modeling System was used for the watershed modeling component of the Methow River Basin study. The Geographic Information System Weasel characterized the physical properties of the basin, and the Precipitation-Runoff Modeling System simulated the natural streamflow. Natural streamflow conditions in the Basin were difficult to calibrate because six of the seven streamflow gaging stations are located below irrigation diversions and few streamflow measurements exist for the study area before the diversions were present. Therefore, limited records of natural streamflow conditions were available and estimations concerning some physical processes could not be quantified. Streamflow was simulated for water years 1992-99 to calibrate the model to measured streamflows. Simulated and measured streamflow generally showed close agreement, especially during spring runoff from snowmelt. Low-flow periods, most restrictive to fish habitation, were simulated reasonably well, yet possessed the most uncertainty. Simulations of the total annual runoff as a percentage of measured annual runoff for the 8-year calibration period at seven gaging stations ranged from -33.7 to +30.5 percent with 70 percent of the simulated values within 16 percent. Simulation of water years

  15. Streamflow characterization and summary of water-quality data collection during the Mississippi River flood, April through July 2011

    USGS Publications Warehouse

    Welch, Heather L.; Barnes, Kimberlee K.

    2013-01-01

    From April through July 2011, the U.S. Geological Survey collected surface-water samples from 69 water-quality stations and 3 flood-control structures in 4 major subbasins of the Mississippi River Basin to characterize the water quality during the 2011 Mississippi River flood. Most stations were sampled at least monthly for field parameters suspended sediment, nutrients, and selected pesticides. Samples were collected at daily to biweekly frequencies at selected sites in the case of suspended sediment. Hydro-carbon analysis was performed on samples collected at two sites in the Atchafalaya River Basin to assess the water-quality implications of opening the Morganza Floodway. Water-quality samples obtained during the flood period were collected at flows well above normal streamflow conditions at the majority of the stations throughout the Mississippi River Basin and its subbasins. Heavy rainfall and snowmelt resulted in high streamflow in the Mississippi River Basin from April through July 2011. The Ohio River Subbasin contributed to most of the flow in the lower Mississippi-Atchafalaya River Subbasin during the months of April and May because of widespread rainfall, whereas snowmelt and precipitation from the Missouri River Subbasin and the upper Mississippi River Subbasin contributed to most of the flow in the lower Mississippi-Atchafalaya River Subbasin during June and July. Peak streamflows from the 2011 flood were higher than peak streamflow during previous historic floods at most the selected streamgages in the Mississippi River Basin. In the Missouri River Subbasin, the volume of water moved during the 1952 flood was greater than the amount move during the 2011 flood. Median concentrations of suspended sediment and total phosphorus were higher in the Missouri River Subbasin during the flood when compared to the other three subbasins. Surface water in the upper Mississippi River Subbasin contained higher median concentrations of total nitrogen, nitrate

  16. 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.

  17. Composition of snowmelt and runoff in northern Michigan

    SciTech Connect

    Cadle, S.H.; Dasch, J.M.; Kopple, R.V.

    1987-03-01

    Snowmelt and runoff were studied during the 1982-1983 and the 1983-1984 winters at the University of Michigan Biological Station, which is located near the northern tip of Michigan's lower peninsula. The first 50% of the snowpack acidity was released in meltwater and rainwater equal to 25% of the original snowpack water content. Interaction between the meltwater and the litter layer produced large changes in the concentrations of most species. Runoff to two streams had high SO/sub 4//sup 2 -/ and very low NO/sub 3//sup -/ concentrations. It is concluded that most of the NO/sub 3//sup -/ is either biologically utilized or retained in the watershed, even during the early snowmelt period at this site. 18 references, 5 figures, 3 tables.

  18. 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

  19. Catchment biophysical drivers of streamflow characteristics

    NASA Astrophysics Data System (ADS)

    Trancoso, R.

    2015-12-01

    The characteristics of streamflow reflect the co-evolution of climate, soils, topography and vegetation of catchments. Hydrological metrics or signatures can represent the long-term behaviour and integrate the influence of all the streamflow drivers. Although this sort of relationship has been developed in regional studies exploring prediction of Flow Duration Curves and other streamflow metrics, little is known about the controls of other key streamflow characteristics especially in continent scale. This study aims to understand how catchment biophysical variables control key hydrological metrics such as baseflow index, elasticity of streamflow to rainfall variability and intermittency in continent scale and regionally. We used a set of catchment biophysical variables to model key streamflow signatures using multivariate power-law and beta regressions in 355 catchments located along the eastern Australian seaboard. Streamflow signatures were derived from daily streamflow time series data from 1980 to 2013. We tested 52 catchment biophysical characteristics related to climate, soil, topography, geography, geomorphology, vegetation and land-cover as predictors of the streamflow signatures. The prediction R-squared ranged from 63 to 72% when relationships are built in continent scale, but can be greater than 80% when regressions are regionalised. The interpretation of the modelled relationships offers new insights regarding the controls of flow characteristics.

  20. Potential impacts of climate change on groundwater recharge and streamflow in a central European low mountain range

    NASA Astrophysics Data System (ADS)

    Eckhardt, K.; Ulbrich, U.

    2003-12-01

    General Circulation Models simulate significant changes of temperature and precipitation over Europe as part of the anthropogenic climate change. In this study, the impacts of climate change on groundwater recharge and streamflow in a central European low mountain range catchment are investigated using a conceptual eco-hydrologic model, a revised version of the Soil and Water Assessment Tool (SWAT). To improve the reliability of our simulations, we compile plant physiological studies concerning the influence of elevated ambient CO 2 concentrations on stomatal conductance and leaf area. Using this information to parameterise the model, we evaluate the impacts of two climate change scenarios, which represent a wide range of assumptions concerning future greenhouse gas emissions and climate sensitivity. The resulting effects on mean annual groundwater recharge and streamflow are small, as increased atmospheric CO 2 levels reduce stomatal conductance thus counteracting increasing potential evapotranspiration induced by the temperature rise and decreasing precipitation. There are, however, more pronounced changes associated with the mean annual cycle of groundwater recharge and streamflow. Our results imply that due to the warming a smaller proportion of the winter precipitation will fall as snow. The spring snowmelt peak therefore is reduced while the flood risk in winter will probably increase. In summer, mean monthly groundwater recharge and streamflow are reduced by up to 50% potentially leading to problems concerning water quality, groundwater withdrawals and hydropower generation.

  1. Hydrology and snowmelt simulation of Snyderville Basin, Park City, and adjacent areas, Summit County, Utah

    USGS Publications Warehouse

    Brooks, Lynette E.; Mason, James L.; Susong, David D.

    1998-01-01

    ground water has the potential to decrease discharge to streams and affect both the amount and quality of surface water in the study area. A comparison of the 1995 to 1994 water budgets emphasizes that the hydrologic system in the study area is very dependent upon the amount of annual precipitation. Although precipitation on the study area was much greater in 1995 than in 1994, most of the additional water resulted in additional streamflow and spring discharge that flows out of the study area. Ground-water levels and groundwater discharge are dependent upon annual precipitation and can vary substantially from year to year.Snowmelt runoff was simulated to assist in estimating ground-water recharge to consolidated rock and unconsolidated valley fill. A topographically distributed snowmelt model controlled by independent inputs of net radiation, meteorological parameters, and snowcover properties was used to calculate the energy and mass balance of the snowcover.

  2. 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

  3. Levels at streamflow gaging stations

    USGS Publications Warehouse

    Kennedy, E.J.

    1990-01-01

    This manual establishes the surveying procedures for (1) setting gages at a streamflow gaging station to datum and (2) checking the gages periodically for errors caused by vertical movement of the structures that support them. Surveying terms and concepts are explained, and procedures for testing, adjusting, and operating the instruments are described in detail. Notekeeping, adjusting level circuits, checking gages, summarizing results, locating the nearest National Geodetic Vertical Datum of 1929 bench mark, and relating the gage datum to the national datum are also described.

  4. 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.

  5. Optimising seasonal streamflow forecast lead time for operational decision making in Australia

    NASA Astrophysics Data System (ADS)

    Schepen, Andrew; Zhao, Tongtiegang; Wang, Q. J.; Zhou, Senlin; Feikema, Paul

    2016-10-01

    Statistical seasonal forecasts of 3-month streamflow totals are released in Australia by the Bureau of Meteorology and updated on a monthly basis. The forecasts are often released in the second week of the forecast period, due to the onerous forecast production process. The current service relies on models built using data for complete calendar months, meaning the forecast production process cannot begin until the first day of the forecast period. Somehow, the bureau needs to transition to a service that provides forecasts before the beginning of the forecast period; timelier forecast release will become critical as sub-seasonal (monthly) forecasts are developed. Increasing the forecast lead time to one month ahead is not considered a viable option for Australian catchments that typically lack any predictability associated with snowmelt. The bureau's forecasts are built around Bayesian joint probability models that have antecedent streamflow, rainfall and climate indices as predictors. In this study, we adapt the modelling approach so that forecasts have any number of days of lead time. Daily streamflow and sea surface temperatures are used to develop predictors based on 28-day sliding windows. Forecasts are produced for 23 forecast locations with 0-14- and 21-day lead time. The forecasts are assessed in terms of continuous ranked probability score (CRPS) skill score and reliability metrics. CRPS skill scores, on average, reduce monotonically with increase in days of lead time, although both positive and negative differences are observed. Considering only skilful forecast locations, CRPS skill scores at 7-day lead time are reduced on average by 4 percentage points, with differences largely contained within +5 to -15 percentage points. A flexible forecasting system that allows for any number of days of lead time could benefit Australian seasonal streamflow forecast users by allowing more time for forecasts to be disseminated, comprehended and made use of prior to

  6. Development of a Precipitation-Runoff Model to Simulate Unregulated Streamflow in the Salmon Creek Basin, Okanogan County, Washington

    USGS Publications Warehouse

    van Heeswijk, Marijke

    2006-01-01

    Surface water has been diverted from the Salmon Creek Basin for irrigation purposes since the early 1900s, when the Bureau of Reclamation built the Okanogan Project. Spring snowmelt runoff is stored in two reservoirs, Conconully Reservoir and Salmon Lake Reservoir, and gradually released during the growing season. As a result of the out-of-basin streamflow diversions, the lower 4.3 miles of Salmon Creek typically has been a dry creek bed for almost 100 years, except during the spring snowmelt season during years of high runoff. To continue meeting the water needs of irrigators but also leave water in lower Salmon Creek for fish passage and to help restore the natural ecosystem, changes are being considered in how the Okanogan Project is operated. This report documents development of a precipitation-runoff model for the Salmon Creek Basin that can be used to simulate daily unregulated streamflows. The precipitation-runoff model is a component of a Decision Support System (DSS) that includes a water-operations model the Bureau of Reclamation plans to develop to study the water resources of the Salmon Creek Basin. The DSS will be similar to the DSS that the Bureau of Reclamation and the U.S. Geological Survey developed previously for the Yakima River Basin in central southern Washington. The precipitation-runoff model was calibrated for water years 1950-89 and tested for water years 1990-96. The model was used to simulate daily streamflows that were aggregated on a monthly basis and calibrated against historical monthly streamflows for Salmon Creek at Conconully Dam. Additional calibration data were provided by the snowpack water-equivalent record for a SNOTEL station in the basin. Model input time series of daily precipitation and minimum and maximum air temperatures were based on data from climate stations in the study area. Historical records of unregulated streamflow for Salmon Creek at Conconully Dam do not exist for water years 1950-96. Instead, estimates of

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. Improving daily streamflow forecasts in mountainous Upper Euphrates basin by multi-layer perceptron model with satellite snow products

    NASA Astrophysics Data System (ADS)

    Uysal, Gökçen; Şensoy, Aynur; Şorman, A. Arda

    2016-12-01

    This paper investigates the contribution of Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Snow Cover Area (SCA) product and in-situ snow depth measurements to Artificial Neural Network model (ANN) based daily streamflow forecasting in a mountainous river basin. In order to represent non-linear structure of the snowmelt process, Multi-Layer Perceptron (MLP) Feed-Forward Backpropagation (FFBP) architecture is developed and applied in Upper Euphrates River Basin (10,275 km2) of Turkey where snowmelt constitutes approximately 2/3 of total annual volume of runoff during spring and early summer months. Snowmelt season is evaluated between March and July; 7 years (2002-2008) seasonal daily data are used during training while 3 years (2009-2011) seasonal daily data are split for forecasting. One of the fastest ANN training algorithms, the Levenberg-Marquardt, is used for optimization of the network weights and biases. The consistency of the network is checked with four performance criteria: coefficient of determination (R2), Nash-Sutcliffe model efficiency (ME), root mean square error (RMSE) and mean absolute error (MAE). According to the results, SCA observations provide useful information for developing of a neural network model to predict snowmelt runoff, whereas snow depth data alone are not sufficient. The highest performance is experienced when total daily precipitation, average air temperature data are combined with satellite snow cover data. The data preprocessing technique of Discrete Wavelet Analysis (DWA) is coupled with MLP modeling to further improve the runoff peak estimates. As a result, Nash-Sutcliffe model efficiency is increased from 0.52 to 0.81 for training and from 0.51 to 0.75 for forecasting. Moreover, the results are compared with that of a conceptual model, Snowmelt Runoff Model (SRM), application using SCA as an input. The importance and the main contribution of this study is to use of satellite snow products and data

  13. A mixture of heavy rainfall, snowmelt, and ice

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC Satellite: Terra Sensor: MODIS Image Date: 06-16-2002 VE Record ID: 13692 Description: A mixture of heavy rainfall, snowmelt, and ice jams in late May and early June of this year caused the Ob River and surrounding tributaries in Western Siberia to overflow their banks. The flooding can be seen in this image taken on June 16, 2002, by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra satellite. Last year, the river flooded farther north. Normally, the river resembles a thin black line.

  14. A Synopsis and Comparison of Selected Snowmelt Algorithms

    DTIC Science & Technology

    1999-07-01

    temperature. (U.S. Army 1956). If humidity data are unavail- When Tp is < 0°C, the meltwater or rain is refro- able, Em is estimated. On days with...iso- During convective storms, Em is computed sepa- thermal, the meltwater is first used to satisfy the rately for each 12-hr period as a function of...layer evo- 8 .Return to contents lution during summer snowmelt on the Greenland water flow scheme is coupled to the equilibrium ice sheet (Rowe et al

  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. Grassed swales for stormwater pollution control during rain and snowmelt.

    PubMed

    Bäckström, M

    2003-01-01

    The retention of suspended solids, particles and heavy metals in different grassed swales during rain events and snowmelt is discussed. The experimental results derived from investigations performed in existing grassed swales in the Luleå region, Northern Sweden. During high pollutant loading rates, grassed swales retain significant amounts of pollutants, mainly due to sedimentation of particulate matter. Low to moderate removal efficiencies could be expected for heavy metals, especially metals in solution (i.e. the dissolved phase). When grassed swales receive urban runoff with low pollutant concentrations, they may release rather than retain pollutants. Swales are important snow deposit areas in the city and particle bound pollutants do to a large extent remain in the swale after snowmelt. However, dissolved pollutants (i.e. dissolved heavy metals) are likely to escape the swale with the melt water. Grassed swales may be regarded as facilities that even out the peaks in pollutant loads without being capable of producing consistent high removal rates. This suggests that swales should be considered as primary treatment devices. Possible design parameters for grassed swales are mean hydraulic detention time, surface loading rate or specific swale area.

  17. Monitoring Water Resources Status with Distributed Snowmelt Model

    NASA Astrophysics Data System (ADS)

    Artan, G.; Dwyer, J.; Verdin, J.; Budde, M.

    2005-12-01

    A large amount of the Afghanistan water supply comes from reservoirs fed by snowmelt runoff, therefore, monitoring the status of snow cover in key areas during the winter and spring is very import to the water resources and disaster management entities of the country. In this study we investigated the utility of monitoring the status of the snow over Afghanistan by employing a spatially distributed snow accumulation and ablation model forced solely with remotely sensed data, weather model assimilation fields, and globally available near-real time meteorological data. The snowmelt model we used was a spatially distributed version of the Utah Energy Balance (UEB) model. A fundamental input variable that went into the model was a dynamic MODIS-based albedo. The MODIS-based snow albedo we used was an integrated 8-days running average value calculated for areas that were established to be cloud-free by the MODIS cloud mask and snow covered by the MODIS snow algorithm (Klein and Stroeve, 2002). The modeled spatial distribution of snow water equivalent provided a good early indication of the relative magnitude of the water available in spring of 2005 for irrigation. The modeled snow water maps were also useful in mapping of basins that were likely to experience a higher risk for floods after the spring snow melts.

  18. Remote sensing of drivers of spring snowmelt flooding in the North Central U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spring snowmelt poses an annual flood risk in non-mountainous regions, such as the northern Great Plains of North America. However, ground observations are often not sufficient to characterize the spatiotemporal variation of drivers of snowmelt floods for operational flood forecasting purposes. Re...

  19. Annual and seasonal fluctuations of precipitation and streamflow in the Aconcagua River basin, Chile

    NASA Astrophysics Data System (ADS)

    Waylen, Peter R.; Caviedes, César N.

    1990-12-01

    The El Niño-Southern Oscillation (ENSO) phenomenon has been shown to influence dramatically precipitation and streamflow in tropical western South America. The statistical properties of annual and winter precipitation totals and streamflow characteristics in the Aconcagua River basin, in temperate central Chile, are investigated in such a way as to permit the identification of flood- and drought-generating processes and their possible linkages to upset behavior in the tropical Pacific. Despite the considerable distance to those regions generally associated with ENSO events, the phenomenon produces marked effects upon the various physical processes which govern the surface hydrometeorology of the study area. El Niño years result in significant increases in annual and winter precipitation, particularly along the coastal margin. The likelihood of rain or rain-on-snow flooding, in the succeeding winter, increases, as does the size of spring snowmelt in the southern summer, 1 year after the upset conditions in the tropical region. Annual low flows are of higher magnitude and occur earlier in the year than is usual.

  20. 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.

  1. 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

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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).

  8. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2007-06-01

    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 m are most sensitive to temperature increases, with CT changes exceeding 45 days (earlier) relative to 1961-1990.

  10. 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...

  11. Geohydrology of stratified drift and streamflow in the Deerfield River basin, northwestern Massachusetts

    USGS Publications Warehouse

    Friesz, P.J.

    1996-01-01

    This report presents the results of a study of the geohydrology of stratified drift and streamflow in the Deerfield River Basin, northwestern Massachusetts. Detailed hydrologic information is needed to plan for the optimal use of ground-water and surface-water resources and for development of new drinking-water supplies in the basin. Sources and percentage of water available for recharge on an annual basis from October 1993 to September 1994, to the fine-grained stratified-drift in a narrow valley bordered by upland till and bedrock were: (1) direct infiltration of precipitation on the valley (30 percent); (2) tributary loss from an upland brook as it crosses the valley (7 percent); and (3) ground- and surface-water runoff from the uplands (63 percent). Seventy percent of recharge was available from upland sources. Seasonal variation in recharge caused changes in ground-water levels and flow directions. In early spring, the direction of flow is toward the valley axis, but in late summer, the direction of flow is nearly parallel to the valley axis. Field observations and results of a ground-water flow simulation indicated that water available for recharge was greater than actual recharge during the spring snowmelt and during intense precipitation events. In 1994, estimates of water available for recharge were greater than actual recharge by 10 percent in March and by 60 percent in April; actual recharge to the valley on an annual basis from October 1993 to September 1994 was 20 percent less than original estimates. A map showing thickness of stratified drift in the Connecticut Valley Lowlands indicates a deep north-south trending buried valley. Maximum thickness of the stratified drift is 385 feet. Interpretation of a seismic-reflection survey indicates fine-grained stratified drift may be underlain by coarse-grained deposits ranging in thickness from 0 to 150 feet. Hydraulic properties of the stratified drift were calculated from ground-water-level fluctuations

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

    DOE PAGES

    Young-Robertson, Jessica M.; Bolton, W. Robert; Bhatt, Uma S.; ...

    2016-07-12

    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 Yukonmore » 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. Furthermore, 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.« less

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

    SciTech Connect

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

    2016-07-12

    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. Furthermore, 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.

  14. 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.

  15. 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

    2016-07-12

    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.

  16. 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

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

    USGS Publications Warehouse

    Young, Jessica; Bolton, W. Robert; Bhatt, Uma; Cristobal, 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.

  18. 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.

  19. 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.

  20. 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

    2016-08-01

    An improved understanding of the temporal variability and the spatial distribution of snowmelt on Antarctic sea ice is crucial to better quantify atmosphere-ice-ocean interactions, in particular sea-ice mass and energy budgets. 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 diurnal brightness temperature differences (dTB(37 GHz)) and ratios (TB(19 GHz)/TB(37 GHz)) to detect and classify snowmelt processes. We distinguish temporary snowmelt from continuous snowmelt to characterize dominant melt patterns for different Antarctic sea-ice regions from 1988/1989 to 2014/2015. Our results indicate four characteristic melt types. On average, 38.9 ± 6.0% of all detected melt events are diurnal freeze-thaw cycles in the surface snow layer, characteristic of temporary melt (Type A). Less than 2% reveal immediate continuous snowmelt throughout the snowpack, i.e., strong melt over a period of several days (Type B). In 11.7 ± 4.0%, Type A and B take place consecutively (Type C), and for 47.8 ± 6.8% no surface melt is observed at all (Type D). Continuous snowmelt is primarily observed in the outflow of the Weddell Gyre and in the northern Ross Sea, usually 17 days after the onset of temporary melt. Comparisons with Snow Buoy data suggest that also the onset of continuous snowmelt does not translate into changes in snow depth for a longer period but might rather affect the internal stratigraphy and density structure of the snowpack. Considering the entire data set, the timing of snowmelt processes does not show significant temporal trends.

  1. 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

  2. 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.

  3. Impacts of Climate Change on Groundwater Recharge and Streamflow in Headwater Catchments in the Yakima River Basin

    NASA Astrophysics Data System (ADS)

    Nguyen, T. T.; Adam, J. C.

    2015-12-01

    Headwater catchments are important sources of surface water supply, groundwater recharge and, thus, groundwater supply for agricultural activities in the Yakima River Basin (YRB, one of the most important agricultural basins in the western U.S). These catchments are, however, vulnerable to projected climate change in future decades, particularly if their runoff is dominated by snowmelt. The goal of this study is to assess the potential impacts of climate change on the temporal and spatial distributions of groundwater recharge and streamflow in three headwater catchments in the YRB. A Regional Hydro-Ecologic Simulation System ("RHESSys") is calibrated and evaluated with a global optimization tool ("Covariance Matrix Adaptation Evolution Strategy - CMA-ES") using 27 years of observation data from 1979 to 2005. Statistically downscaled climate projections for the 2050s from four global climate models driven by two different representative concentration pathways, RCP4.5 and RCP8.5 are used to predict future hydrologic changes. Our preliminary results show an increase in annual recharge between 2% and 13%, as well as in streamflow between 1% and 17%. Seasonal changes of recharge and streamflow are more pronounced with an increase up to 210% in winters and a decrease as high as 60% in summers in the 2050s. Both recharge and streamflow projections indicate timing shifts in all three catchments. The outcome from this study will be an integral part of a future study which investigates the impacts of climate change on surface water vulnerability due to supplemental pumping, potential recharge changes and related surface-groundwater interactions in the YRB using an integrated modeling approach that consists of three models: RHESSys, a groundwater model (MODFLOW) and a river and reservoir management model (RiverWare).

  4. Streamflow sensitivity to water storage changes across Europe

    NASA Astrophysics Data System (ADS)

    Berghuijs, Wouter; Hartmann, Andreas; Woods, Ross

    2016-04-01

    Terrestrial water storage is the primary source of river flow. We introduce storage sensitivity of streamflow, which for a given flow rate indicates the relative change in streamflow per change in catchment water storage. Storage sensitivity of streamflow can be directly derived from streamflow observations. Analysis of 725 catchments in Europe reveals that storage sensitivity of streamflow 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 comparison of storage sensitivity of streamflow with observations suggests that storage sensitivity of streamflow is a significant control on the regional differences in variability of low, median, and high flow conditions. Streamflow sensitivity provides new guidance for a changing hydrosphere where groundwater abstraction and climatic changes are altering water storage and flow regimes.

  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. Trends in streamflow in the Yukon River Basin from 1944 to 2005 and the influence of the Pacific Decadal Oscillation

    USGS Publications Warehouse

    Brabets, T.P.; Walvoord, M.A.

    2009-01-01

    Streamflow characteristics in the Yukon River Basin of Alaska and Canada have changed from 1944 to 2005, and some of the change can be attributed to the two most recent modes of the Pacific Decadal Oscillation (PDO). Seasonal, monthly, and annual stream discharge data from 21 stations in the Yukon River Basin were analyzed for trends over the entire period of record, generally spanning 4-6 decades, and examined for differences between the two most recent modes of the PDO: cold-PDO (1944-1975) and warm-PDO (1976-2005) subsets. Between 1944 and 2005, average winter and April flow increased at 15 sites. Observed winter flow increases during the cold-PDO phase were generally limited to sites in the Upper Yukon River Basin. Positive trends in winter flow during the warm-PDO phase broadened to include stations in the Middle and Lower Yukon River drainage basins. Increases in winter streamflow most likely result from groundwater input enhanced by permafrost thawing that promotes infiltration and deeper subsurface flow paths. Increased April flow may be attributed to a combination of greater baseflow (from groundwater increases), earlier spring snowmelt and runoff, and increased winter precipitation, depending on location. Calculated deviations from long-term mean monthly discharges indicate below-average flow in the winter months during the cold PDO and above-average flow in the winter months during the warm PDO. Although not as strong a signal, results also support the reverse response during the summer months: above-average flow during the cold PDO and below-average flow during the warm PDO. Changes in the summer flows are likely an indirect consequence of the PDO, resulting from earlier spring snowmelt runoff and also perhaps increased summer infiltration and storage in a deeper active layer. Annual discharge has remained relatively unchanged in the Yukon River Basin, but a few glacier-fed rivers demonstrate positive trends, which can be attributed to enhanced glacier

  7. 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

  8. Hydrologic Streamflow Conditions for Georgia, 2007

    USGS Publications Warehouse

    Knaak, Andrew E.; Joiner, John K.

    2008-01-01

    The U.S. Geologic Survey (USGS) Georgia Water Science Center (GaWSC) maintains a long-term hydrologic monitoring network of more than 260 real-time streamflow stations and more than 100 noncontinuous streamflow stations throughout Georgia. This network is operated by the USGS GaWSC in cooperation with more than 50 different partners at Federal, State, and local government levels. One of the many benefits of data collected from this monitoring network is that it allows for the analysis of the overall hydrologic condition of streams and lakes of Georgia.

  9. Transport of plutonium in snowmelt run-off

    SciTech Connect

    Purtymun, W.D.; Peters, R.; Maes, M.N.

    1990-07-01

    Plutonium in treated low-level radioactive effluents released into intermittent streams is bound by ion exchange or adsorption to bed sediments in the stream channel. These sediments are subject to transport with summer and spring snowmelt run-off. A study was made of the transport of plutonium during seven spring run-off events in Los Alamos and Pueblo canyons from the Laboratory boundary to Otowi on the Rio Grande. The melting of the snowpack during these years resulted in run-off that was large enough to reach the eastern edge of the Laboratory. Of these seven run-off events recorded at the Laboratory boundary, only five had sufficient flow to reach the Rio Grande. The volume of the five events that reached the river ranged from 5 {times} 10{sup 3} m{sup 3} to 104 {times} 10{sup 3} m{sup 3}. The five run-off events carried 119 {times} 10{sup 3} kg of suspended sediments and 1073 {times} 10{sup 3} kg of bed sediments, and transported 598 {mu}Ci of plutonium to the river. Of the 598 {mu}Ci of plutonium, 3% was transported in solution, 57% with suspended sediments, and 40% with bed sediments. 13 refs., 3 figs., 6 tabs.

  10. Metal distributions in soil receiving urban pavement runoff and snowmelt.

    PubMed

    Sansalone, John J; Glenn, Donald W

    2007-07-01

    Wet and dry deposition of anthropogenic metals and particulates generated from urban and traffic activities can result in contamination of urban-land-use soils. These particulate residuals encompass a wide size gradation, from 1 to greater than 10 000 microm. This study hypothesized that such contamination of surficial soils can be analyzed and explained as a function of the soil/residual granulometry. This study analyzed the gradation-based physical characteristics for 10 urban transportation land-use sites with soil/residual complexes (SRCs) located throughout metropolitan Cincinnati, Ohio, and an urban residential reference site. Particle density (rho(s)) of SRCs ranged from 2.8 to 2.1 g/cm3, with the lower particle density associated with particles less than 100 microm. For each site, specific surface area generally increased with decreasing particle size, while the predominance of total surface area was associated with the coarser size fractions, except for the clayey glacial till reference site not influenced by traffic. Cumulative analysis for lead, copper, cadmium, and zinc associated with SRCs indicated that more than 50% of the metal mass was associated with particles greater than 250 microm, with more than 80% associated with particles greater than 106 microm. Study results are similar to rainfall-runoff and snowmelt distributions. Results provide guidance when considering potential fate and control of metals transported by urban drainage and are distributed across the SRC size gradation.

  11. THE INFLUENCE OF THE SPATIAL DISTRIBUTION OF SNOW ON BASIN-AVERAGED SNOWMELT. (R824784)

    EPA Science Inventory

    Spatial variability in snow accumulation and melt owing to topographic effects on solar radiation, snow drifting, air temperature and precipitation is important in determining the timing of snowmelt releases. Precipitation and temperature effects related to topography affect snow...

  12. Soil-water dynamics and unsaturated storage during snowmelt following wildfire

    USGS Publications Warehouse

    Ebel, Brian A.; Hinckley, E.S.; Martin, Deborah

    2012-01-01

    Many forested watersheds with a substantial fraction of precipitation delivered as snow have the potential for landscape disturbance by wildfire. Little is known about the immediate effects of wildfire on snowmelt and near-surface hydrologic responses, including soil-water storage. Montane systems at the rain-snow transition have soil-water dynamics that are further complicated during the snowmelt period by strong aspect controls on snowmelt and soil thawing. Here we present data from field measurements of snow hydrology and subsurface hydrologic and temperature responses during the first winter and spring after the September 2010 Fourmile Canyon Fire in Colorado, USA. Our observations of soil-water content and soil temperature show sharp contrasts in hydrologic and thermal conditions between north- and south-facing slopes. South-facing burned soils were ∼1–2 °C warmer on average than north-facing burned soils and ∼1.5 °C warmer than south-facing unburned soils, which affected soil thawing during the snowmelt period. Soil-water dynamics also differed by aspect: in response to soil thawing, soil-water content increased approximately one month earlier on south-facing burned slopes than on north-facing burned slopes. While aspect and wildfire affect soil-water dynamics during snowmelt, soil-water storage at the end of the snowmelt period reached the value at field capacity for each plot, suggesting that post-snowmelt unsaturated storage was not substantially influenced by aspect in wildfire-affected areas. Our data and analysis indicate that the amount of snowmelt-driven groundwater recharge may be larger in wildfire-impacted areas, especially on south-facing slopes, because of earlier soil thaw and longer durations of soil-water contents above field capacity in those areas.

  13. 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.

  14. Snow-fed streamflow timing at different basin scales: Case study of the Tuolumne River above Hetch Hetchy, Yosemite, California

    NASA Astrophysics Data System (ADS)

    Lundquist, Jessica D.; Dettinger, Michael D.; Cayan, Daniel R.

    2005-07-01

    Diurnal cycles in snow-fed streams provide a useful technique for measuring the time it takes water to travel from the top of the snowpack, where snowmelt typically peaks in the afternoon, to the river gauge, where the daily maximum flows may arrive many hours later. Hourly stage measurements in nested subbasins (6-775 km2) of the Tuolumne River in Yosemite National Park illustrate travel time delays at different basin scales during the spring 2002 and 2003 melt seasons. Travel times increase with longer percolation times through deeper snowpacks, increase with longer travel times over land and along longer stream channels, and increase with slower in-stream flow velocities. In basins smaller than 30 km2, travel times through the snowpack dominate streamflow timing. In particular, daily peak flows shift to earlier in the day as snowpacks thin and mean discharges increase. In basins larger than 200 km2, snowpack heterogeneity causes the hour of peak flow to be highly consistent, with little or no variation as the snowpack thins. Basins with areas in between 30 and 200 km2 exhibit different sequences of diurnal streamflow timing in different years, sometimes acting like small basins and other times like large basins. From the start of the melt season until the day of peak snowmelt discharge, increasing travel distances in channels as the snow line retreats to higher elevations do not cause long enough travel delays to offset the observed decrease in mean travel times through the snowpack. A model that couples porous medium flow through thinning snowpacks with free surface flow in stream channels can reproduce the observed patterns, provided that the model incorporates snowpack heterogeneity.

  15. Snow-fed streamflow timing at different basin scales: Case study of the Tuolumne River above Hetch Hetchy, Yosemite, California

    USGS Publications Warehouse

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

    2005-01-01

    Diurnal cycles in snow-fed streams provide a useful technique for measuring the time it takes water to travel from the top of the snowpack, where snowmelt typically peaks in the afternoon, to the river gauge, where the daily maximum flows may arrive many hours later. Hourly stage measurements in nested subbasins (6-775 km2) of the Tuolumne River in Yosemite National Park illustrate travel time delays at different basin scales during the spring 2002 and 2003 melt seasons. Travel times increase with longer percolation times through deeper snowpacks, increase with longer travel times over land and along longer stream channels, and increase with slower in-stream flow velocities. In basins smaller than 30 km2, travel times through the snowpack dominate streamflow timing. In particular, daily peak flows shift to earlier in the day as snowpacks thin and mean discharges increase. In basins larger than 200 km2, snowpack heterogeneity causes the hour of peak flow to be highly consistent, with little or no variation as the snowpack thins. Basins with areas in between 30 and 200 km2 exhibit different sequences of diurnal streamflow timing in different years, sometimes acting like small basins and other times like large basins. From the start of the melt season until the day of peak snowmelt discharge, increasing travel distances in channels as the snow line retreats to higher elevations do not cause long enough travel delays to offset the observed decrease in mean travel times through the snowpack. A model that couples porous medium flow through thinning snowpacks with free surface flow in stream channels can reproduce the observed patterns, provided that the model incorporates snowpack heterogeneity. Copyright 2005 by the American Geophysical Union.

  16. 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.

  17. 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.

  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. 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.

  1. 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.

  2. Streamflow depletion by wells--Understanding and managing the effects of groundwater pumping on streamflow

    USGS Publications Warehouse

    Barlow, Paul M.; Leake, Stanley A.

    2012-11-02

    Groundwater is an important source of water for many human needs, including public supply, agriculture, and industry. With the development of any natural resource, however, adverse consequences may be associated with its use. One of the primary concerns related to the development of groundwater resources is the effect of groundwater pumping on streamflow. Groundwater and surface-water systems are connected, and groundwater discharge is often a substantial component of the total flow of a stream. Groundwater pumping reduces the amount of groundwater that flows to streams and, in some cases, can draw streamflow into the underlying groundwater system. Streamflow reductions (or depletions) caused by pumping have become an important water-resource management issue because of the negative impacts that reduced flows can have on aquatic ecosystems, the availability of surface water, and the quality and aesthetic value of streams and rivers. Scientific research over the past seven decades has made important contributions to the basic understanding of the processes and factors that affect streamflow depletion by wells. Moreover, advances in methods for simulating groundwater systems with computer models provide powerful tools for estimating the rates, locations, and timing of streamflow depletion in response to groundwater pumping and for evaluating alternative approaches for managing streamflow depletion. The primary objective of this report is to summarize these scientific insights and to describe the various field methods and modeling approaches that can be used to understand and manage streamflow depletion. A secondary objective is to highlight several misconceptions concerning streamflow depletion and to explain why these misconceptions are incorrect.

  3. Rainfall and Streamflow Variability in Ghana

    NASA Astrophysics Data System (ADS)

    Tanu, Michael M.

    The objective of this research is to investigate the variability of rainfall and streamflow over Ghana. Analyses of rainfall shows larger daily variability and maxima amounts in the southern coastal belt than in either the middle or northern parts of the country. The high variability in rainfall at the coast is associated with sea surface temperatures (SSTs) changes over the Guinea coast. This is related to the evolution of the cold tongue over the Atlantic during the rainfall season. The results indicate that the extreme rainfall events occur as single events, but there are occasions when they occur sequentially, and some of these events could continue for more than 5 days. We note that the average SSTs over the equatorial Atlantic favor the occurrence of extreme rainfall over the coastal and middle belt, while relatively cold SSTs favor the occurrence of extreme rainfall events in the northern belt. This study also shows the presence of eastward moving convective signals which are associated with Kelvin waves that impact the rainfall in spring over Ghana. Kelvin waves account for ~70% of the extreme rainfall events during boreal spring compared to 25%-35% in summer. The reason for this is that the rainfall in southern Ghana peaks in spring when the frequency of propagation of these waves is the highest. Analysis of streamflow and rainfall suggested that both rainfall and streamflow exhibit a bimodal pattern. Although the peak in rainfall occurs during the major season, the peak in streamflow occurs during the minor season. Extreme rainfall events are more associated with flooding in the rivers than continuous non-extreme rainfall events. Additionally, we note a decreasing trend in rainfall and streamflow over the southern part of Ghana. But, the decrease in streamflow is larger than for the rainfall. It is to be noted, however, that the draw of water from the two rivers by the communities for domestic and irrigation use are very difficult to quantify and could be

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. Evaluation of climate modeling factors impacting the variance of streamflow

    NASA Astrophysics Data System (ADS)

    Al Aamery, N.; Fox, J. F.; Snyder, M.

    2016-11-01

    The present contribution quantifies the relative importance of climate modeling factors and chosen response variables upon controlling the variance of streamflow forecasted with global climate model (GCM) projections, which has not been attempted in previous literature to our knowledge. We designed an experiment that varied climate modeling factors, including GCM type, project phase, emission scenario, downscaling method, and bias correction. The streamflow response variable was also varied and included forecasted streamflow and difference in forecast and hindcast streamflow predictions. GCM results and the Soil Water Assessment Tool (SWAT) were used to predict streamflow for a wet, temperate watershed in central Kentucky USA. After calibrating the streamflow model, 112 climate realizations were simulated within the streamflow model and then analyzed on a monthly basis using analysis of variance. Analysis of variance results indicate that the difference in forecast and hindcast streamflow predictions is a function of GCM type, climate model project phase, and downscaling approach. The prediction of forecasted streamflow is a function of GCM type, project phase, downscaling method, emission scenario, and bias correction method. The results indicate the relative importance of the five climate modeling factors when designing streamflow prediction ensembles and quantify the reduction in uncertainty associated with coupling the climate results with the hydrologic model when subtracting the hindcast simulations. Thereafter, analysis of streamflow prediction ensembles with different numbers of realizations show that use of all available realizations is unneeded for the study system, so long as the ensemble design is well balanced. After accounting for the factors controlling streamflow variance, results show that predicted average monthly change in streamflow tends to follow precipitation changes and result in a net increase in the average annual precipitation and

  10. 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.

  11. 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.

  12. 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.

  13. Terrestrial–aquatic linkages in spring-fed and snowmelt-dominated streams

    USGS Publications Warehouse

    Sepulveda, Adam

    2017-01-01

    The importance of trophic linkages between aquatic and terrestrial ecosystems is predicted to vary as a function of subsidy quantity and quality relative to in situ resources. To test this prediction, I used multi-year diet data from Bonneville cutthroat trout Oncorhynchus clarki Utah in spring-fed and snowmelt-driven streams in the high desert of western North America. I documented that trout in spring-fed streams consumed more (number and weight) aquatic than terrestrial invertebrates, while trout in snowmelt-driven streams consumed a similar number of both prey types but consumed more terrestrial than aquatic invertebrates by weight. Trout in spring-fed streams consumed more aquatic invertebrates than trout in snowmelt streams and trout consumed more terrestrial invertebrates in snowmelt than in spring-fed streams. Up to 93% of trout production in spring-fed streams and 60% in snowmelt streams was fueled by aquatic invertebrates, while the remainder of trout production in each stream type was from terrestrial production. I found that the biomass and occurrence of consumed terrestrial invertebrates were not related to our measures of in situ resource quality or quantity in either stream type. These empirical data highlight the importance of autotrophic-derived production to trout in xeric regions.

  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. [Spectral characters analysis of ground objects in snowmelt period in the northern slope of Tianshan Mountains].

    PubMed

    Fang, Shi-Feng; Pei, Huan; Liu, Zhi-Hui

    2010-05-01

    Urumqi River Basin and Juntanghu Basin, located in the northern slope of Tianshan Mountains in Xinjiang, were selected as typical study areas. With the portable field spectrometer CI700 produced by CID in the United States and from a large number of field investigations and field measurements in the snowmelt period (usually starts in the end of February or the beginning of March, and goes on for many days) from 2006 to 2009, a variety of spectral curves and their variation of typical ground objects in the snowmelt period in the northern slope of Tianshan Mountains, such as snow, ice, water and soil, were obtained, and spectral characters analysis was carried out based on the collected data. The results showed that the classes of ground objects in snowmelt period are quite monotone, however, a great challenge was brought about to the quantitative remote sensing research on surface parameters in snowmelt period because of the interactive effects of the complex systems of snow-ice-water-soil, the spectral properties of typical ground objects, and their complex changes. Reflectance of soil with different moisture conditions is distinct, as well as reflectance of ice and snow under different environment or dissimilar mixtures have obvious development trends. The series of observations and analysis of the typical and complex spectral features in snowmelt period are of great significance for the fundamental study of objects' spectral characteristics, as well as for the application of quantitative remote sensing studies.

  16. Snowmelt infiltration and evapotranspiration in Red Fir forest ecosystems of the Sierra Nevada

    NASA Astrophysics Data System (ADS)

    Kirchner, P. B.; Bales, R. C.; North, M. P.; Small, E. E.

    2008-12-01

    Measurements from two forested catchments in the mixed conifer, Red Fir zone of the southern Sierra Nevada (2,200-2,600 m elevation) demonstrate the controls that topography and canopy cover exert over snow cover. Snow-depth, soil-moisture, stream-stage and sap-flow measurements from the Wolverton basin in Sequoia National Park and Teakettle Experimental Area in the Sierra National Forest exhibit distinct and rapid responses to spring snowmelt. Spatial heterogeneity in snow water equivalent is influenced by tree clusters and individual canopies. Snowmelt and soil moisture timing are controlled by proximity to stem of tree and canopy clustering. Aspect and slope position affect soil moisture, with drier conditions predominating on the steeper slopes. Synchronous fluctuations in soil moisture, stream flow and sap flow were observed. Continuous instrumental and synoptic survey data show snow water equivalent is approximately 15% less 1 m from the tree stem than in open areas at peak accumulation, with snowmelt occurring in shaded open areas 1 to 4 weeks later than under canopy. Soil moisture tracks the snowmelt pattern closely, with diel fluctuations in soil moisture under saturated conditions followed by an exponential dry-down to field capacity after snowmelt. This is followed by a prolonged summer drought punctuated by rain events of <5% of total precipitation. Synoptic surveys of steeper slopes and multiple aspects show consistent patterns of drier conditions on steeper terrain.

  17. 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)

  18. Streamflow trends in the United States

    USGS Publications Warehouse

    Lins, H.F.; Slack, J.R.

    1999-01-01

    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.

  19. 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).

  20. 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…

  1. 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.

  2. 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

  3. Streamflow of 2006 -- Water Year Summary

    USGS Publications Warehouse

    Lins, Harry

    2007-01-01

    The maps and graphs appearing in this summary describe streamflow conditions for water-year 2006 (October 1, 2005 to September 30, 2006) in the context of the 77-year period 1930-2006, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey's (USGS) National Streamflow Information Program. The period 1930-2006 was used because prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term 'runoff,' which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a single year was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation's rivers and streams in measurement units that can be compared from one area to another. The runoff value for a geographic area is computed as the median runoff value for all streamgages in that geographic area. For example, the runoff value for a state is the median for all streamgages in that state, and the median for the Nation is the median value for all streamgages in the Nation. Each of the maps and graphs below can be expanded to a larger view by clicking on the image. In all the graphics, a rank of 1 indicates the highest flow of all years analyzed.

  4. Streamflow simulations of the terrestrial Arctic domain

    NASA Astrophysics Data System (ADS)

    Su, Fengge; Adam, Jennifer C.; Bowling, Laura C.; Lettenmaier, Dennis P.

    2005-04-01

    Predicting riverine discharge to the Arctic Ocean has become increasingly important because of the dominant role that river runoff plays in the freshwater balance of the Arctic Ocean, and the predicted high sensitivity of the region to global warming. The ability of land surface models to represent runoff and streamflow from northern river basins is critical to an understanding of the Arctic hydrologic cycle. A set of simulations with the land surface scheme VIC (Variable Infiltration Capacity) implemented at 100 km EASE-Grid across the pan-Arctic domain was conducted to evaluate the model's representation of various hydrologic processes in the Arctic land region, and to provide a consistent baseline hydroclimatology for the region. The pan-Arctic drainage basin system was partitioned into 12 regions for purposes of model implementation and testing. Streamflow observations at various basin outlets, satellite-based snow cover extent, observed dates of lake freeze-up and break-up, and sited monitored summer permafrost maximum active layer thickness were used to evaluate various simulated hydrologic variables. The results indicate that the VIC model was able to reproduce these hydrologic processes in the Arctic region. A 21-year average river inflow (1979-1999) to the Arctic Ocean from the AORB (Arctic Ocean River Basin) illustrated in Prowse and Flegg (2000), was estimated with the simulated streamflow as 3354 km3/yr, and 3596 km3/yr with the inclusion of the Arctic Archepelago, which are comparable to the previous estimates derived from the observed data.

  5. Streamflow of 2011 - Water Year Summary

    USGS Publications Warehouse

    Jian, Xiaodong; Wolock, David M.; Lins, Harry F.; Brady, Steve

    2012-01-01

    The maps and graph in this summary describe streamflow conditions for water year 2011 (October 1, 2010, to September 30, 2011) in the context of the 82-year period from 1930 through 2011, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey's (USGS) National Streamflow Information Program (http://water.usgs.gov/nsip/). The period 1930-2010 was used because, prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term "runoff," which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a single year was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation's rivers and streams in measurement units that can be compared from one area to another. Each of the maps and graphs can be expanded to a larger view by clicking on the image. In all of the graphics, a rank of 1 indicates the highest flow of all years analyzed.

  6. Streamflow of 2007--Water year summary

    USGS Publications Warehouse

    Xiaodong, Jian; Wolock, David M.; Lins, Harry F.

    2008-01-01

    The maps and graphs appearing in this summary describe streamflow conditions for water-year 2007 (October 1, 2006 to September 30, 2007) in the context of the 78-year period 1930-2007, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey's (USGS) National Streamflow Information Program. The period 1930-2007 was used because prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term "runoff," which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a single year was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation's rivers and streams in measurement units that can be compared from one area to another. The runoff value for a geographic area is computed as the median runoff value for all streamgages in that geographic area. For example, the runoff value for a State is the median for all streamgages in that State, and the median for the Nation is the median value for all streamgages in the Nation. Each of the maps and graphs below can be expanded to a larger view by clicking on the image. In all the graphics, a rank of 1 indicates the highest flow of all years analyzed.

  7. Streamflow of 2008--Water year summary

    USGS Publications Warehouse

    Xiaodong, Jian; Wolock, David M.; Lins, Harry F.; Brady, Steve

    2009-01-01

    The maps and graphs appearing in this summary describe streamflow conditions for water-year 2008 (October 1, 2007 to September 30, 2008) in the context of the 79-year period 1930-2008, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey's (USGS) National Streamflow Information Program. The period 1930-2008 was used because prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term "runoff," which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a single year was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation's rivers and streams in measurement units that can be compared from one area to another. The runoff value for a geographic area is computed as the median runoff value for all streamgages in that geographic area. For example, the runoff value for a State is the median for all streamgages in that State, and the median for the Nation is the median value for all streamgages in the Nation. Each of the maps and graphs below can be expanded to a larger view by clicking on the image. In all the graphics, a rank of 1 indicates the highest flow of all years analyzed.

  8. Streamflow of 2010--Water year summary

    USGS Publications Warehouse

    Xiaodong, Jian; Wolock, David M.; Lins, Harry F.; Brady, Steve

    2011-01-01

    The maps and graph in this summary describe streamflow conditions for water-year 2010 (October 1, 2009 to September 30, 2010) in the context of the 81-year period 1930-2010, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey's (USGS) National Streamflow Information Program. The period 1930-2010 was used because prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term "runoff," which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a single year was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation's rivers and streams in measurement units that can be compared from one area to another. Each of the maps and graphs below can be expanded to a larger view by clicking on the image. In all the graphics, a rank of 1 indicates the highest flow of all years analyzed.

  9. Streamflow of 2012--Water Year Summary

    USGS Publications Warehouse

    Jian, Xiaodong; Wolock, David M.; Lins, Harry F.; Brady, Steve

    2013-01-01

    The maps and graphs in this summary describe streamflow conditions for water year 2012 (October 1, 2011, to September 30, 2012) in the context of the 83-year period from 1930 through 2012, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey’s (USGS) National Streamflow Information Program (http://water.usgs.gov/nsip/). The period 1930–2012 was used because, prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term “runoff,” which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a specified time period was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation’s rivers and streams in measurement units that can be compared from one area to another.

  10. Streamflow of 2009--Water year summary

    USGS Publications Warehouse

    Xiaodong, Jian; Wolock, David M.; Lins, Harry F.; Brady, Steve

    2010-01-01

    The maps and graph in this summary describe streamflow conditions for water-year 2009 (October 1, 2008 to September 30, 2009) in the context of the 80-year period 1930-2009, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey's National Streamflow Information Program. The period 1930-2009 was used because prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term "runoff," which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a single year was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation's rivers and streams in measurement units that can be compared from one area to another. Each of the maps and graphs can be expanded to a larger view by clicking on the image. In all the graphics, a rank of 1 indicates the highest flow of all years analyzed.

  11. Streamflow and water balance intercomparisons of four land surface models in the North American Land Data Assimilation System project

    NASA Astrophysics Data System (ADS)

    Lohmann, Dag; Mitchell, Kenneth E.; Houser, Paul R.; Wood, Eric F.; Schaake, John C.; Robock, Alan; Cosgrove, Brian A.; Sheffield, Justin; Duan, Qingyun; Luo, Lifeng; Higgins, R. Wayne; Pinker, Rachel T.; Tarpley, J. Dan

    2004-04-01

    This paper is part of a series of papers about the multi-institutional North American Land Data Assimilation System (NLDAS) project. It compares and evaluates streamflow and water balance results from four different land surface models (LSMs) within the continental United States. These LSMs have been run for the retrospective period from 1 October 1996 to 30 September 1999 forced by atmospheric observations from the Eta Data Assimilation System (EDAS) analysis, measured precipitation, and satellite-derived downward solar radiation. These model runs were performed on a common 1/8° latitude-longitude grid and used the same database for soil and vegetation classifications. We have evaluated these simulations using U.S. Geological Survey (USGS) measured daily streamflow data for 9 large major basins and 1145 small- to medium-sized basins from 23 km2 to 10,000 km2 distributed over the NLDAS domain. Model runoff was routed with a common distributed and a lumped optimized linear routing model. The diagnosis of the model water balance results demonstrates strengths and weaknesses in the models, our insufficient knowledge of ad hoc parameters used for the model runs, the interdependence of model structure and model physics, and the lack of good forcing data in parts of the United States, especially in regions with extended snow cover. Overall, the differences between the LSM water balance terms are of the same magnitude as the mean water balance terms themselves. The modeled mean annual runoff shows large regional differences by a factor of up to 4 between models. The corresponding difference in mean annual evapotranspiration is about a factor of 2. The analysis of runoff timing for the LSMs demonstrates the importance of correct snowmelt timing, where the resulting differences in streamflow timing can be up to four months. Runoff is underestimated by all LSMs in areas with significant snowfall.

  12. 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.

  13. Modeling Change in Watershed Streamflow, Groundwater Recharge and Surface Water - Groundwater Interactions Due to Irrigation and Associated Diversions and Pumping

    NASA Astrophysics Data System (ADS)

    Essaid, H.; Caldwell, R. R.

    2015-12-01

    The impacts of irrigation and associated surface water (SW) diversions and groundwater (GW) pumping on instream flows, groundwater recharge and SW-GW interactions are being examined using a watershed-scale coupled SW-GW flow model. The U.S. Geological Survey (USGS) model GSFLOW (Markstrom et al., 2008), an integration of the USGS Precipitation-Runoff Modeling System (PRMS) and the Modular Ground-Water Flow Model (MODFLOW), is being utilized for this effort. Processes represented in this model include daily rain, snowfall, snowmelt, streamflow, surface runoff, interflow, infiltration, soil-zone evapotranspiration, and subsurface unsaturated and groundwater flow and evapotranspiration. The Upper Smith River watershed, an important agricultural and recreational area in west-central Montana, is being used as the basis for watershed climate, topography, hydrography, vegetation, soil properties as well as scenarios of irrigation and associated practices. The 640 square kilometer watershed area has been discretized into coincident 200 m by 200 m hydrologic response units (for climate and soil zone flow processes) and grid blocks (for unsaturated zone and GW flow processes). The subsurface GW system is discretized into 6 layers representing Quaternary alluvium, Tertiary sediments and bedrock. The model is being used to recreate natural, pre-development streamflows and GW conditions in the watershed. The results of this simulation are then compared to a simulation with flood and sprinkler irrigation supplied by SW diversion and GW pumping to examine the magnitude and timing of changes in streamflow, groundwater recharge and SW-GW interactions. Model results reproduce observed hydrologic responses to both natural climate variability and irrigation practices. Periodic irrigation creates increased evapotranspiration and GW recharge in cultivated areas of the watershed as well as SW-GW interactions that are more dynamic than under natural conditions.

  14. 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).

  15. Modulation of snow reflectance and snowmelt from Central Asian glaciers by anthropogenic black carbon

    PubMed Central

    Schmale, Julia; Flanner, Mark; Kang, Shichang; Sprenger, Michael; Zhang, Qianggong; Guo, Junming; Li, Yang; Schwikowski, Margit; Farinotti, Daniel

    2017-01-01

    Deposited mineral dust and black carbon are known to reduce the albedo of snow and enhance melt. Here we estimate the contribution of anthropogenic black carbon (BC) to snowmelt in glacier accumulation zones of Central Asia based on in-situ measurements and modelling. Source apportionment suggests that more than 94% of the BC is emitted from mostly regional anthropogenic sources while the remaining contribution comes from natural biomass burning. Even though the annual deposition flux of mineral dust can be up to 20 times higher than that of BC, we find that anthropogenic BC causes the majority (60% on average) of snow darkening. This leads to summer snowmelt rate increases of up to 6.3% (7 cm a−1) on glaciers in three different mountain environments in Kyrgyzstan, based on albedo reduction and snowmelt models. PMID:28079148

  16. Modulation of snow reflectance and snowmelt from Central Asian glaciers by anthropogenic black carbon

    NASA Astrophysics Data System (ADS)

    Schmale, Julia; Flanner, Mark; Kang, Shichang; Sprenger, Michael; Zhang, Qianggong; Guo, Junming; Li, Yang; Schwikowski, Margit; Farinotti, Daniel

    2017-01-01

    Deposited mineral dust and black carbon are known to reduce the albedo of snow and enhance melt. Here we estimate the contribution of anthropogenic black carbon (BC) to snowmelt in glacier accumulation zones of Central Asia based on in-situ measurements and modelling. Source apportionment suggests that more than 94% of the BC is emitted from mostly regional anthropogenic sources while the remaining contribution comes from natural biomass burning. Even though the annual deposition flux of mineral dust can be up to 20 times higher than that of BC, we find that anthropogenic BC causes the majority (60% on average) of snow darkening. This leads to summer snowmelt rate increases of up to 6.3% (7 cm a‑1) on glaciers in three different mountain environments in Kyrgyzstan, based on albedo reduction and snowmelt models.

  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. The impact of climate change on the accuracy of streamflow predictions in California

    NASA Astrophysics Data System (ADS)

    Leonardson, R.; Vicuna, S.; Dracup, J. A.; Dale, L. L.

    2005-12-01

    Every spring, California's Department of Water Resources (DWR) forecasts streamflow for the upcoming irrigation season (April-July) for rivers fed by the Western Sierra snowpack. The DWR forecasts influence water allocations, cropping strategy, and flood and drought management plans; forecast error can impact California's economy, especially the agricultural sector. Demand for water is expected to increase with population growth and climate change effects, in which the summers will be longer and hotter. At the same time, the percentage of precipitation falling as snow will shrink, and the snowpack is expected to melt earlier. We expect both of these factors to reduce forecast accuracy, as forecasting rainfall is less precise than measuring snowpack and because less of the snowpack will remain after April 1st. In this study, we examine relationships between historical forecast error and watershed elevation, snowpack size, snowmelt timing (as hydrograph center-of-mass), and other factors. We quantify expected future error using the predictions of multiple global circulation models and various emissions scenarios.

  19. Mississippi River streamflow measurement techniques at St. Louis, Missouri

    USGS Publications Warehouse

    Wastson, Chester C.; Holmes, Jr., Robert R.; Biedenham, David S.

    2013-01-01

    Streamflow measurement techniques of the Mississippi River at St. Louis have changed through time (1866–present). In addition to different methods used for discrete streamflow measurements, the density and range of discrete measurements used to define the rating curve (stage versus streamflow) have also changed. Several authors have utilized published water surface elevation (stage) and streamflow data to assess changes in the rating curve, which may be attributed to be caused by flood control and/or navigation structures. The purpose of this paper is to provide a thorough review of the available flow measurement data and techniques and to assess how a strict awareness of the limitations of the data may affect previous analyses. It is concluded that the pre-1930s discrete streamflow measurement data are not of sufficient accuracy to be compared with modern streamflow values in establishing long-term trends of river behavior.

  20. Statistical Summaries of Streamflow in and near Oklahoma Through 2007

    USGS Publications Warehouse

    Lewis, Jason M.; Esralew, Rachel A.

    2009-01-01

    Statistical summaries of streamflow records through 2007 for gaging stations in Oklahoma and parts of adjacent states are presented for 238 stations with at least 10 years of streamflow record. Streamflow at 120 of the stations is regulated for specific periods. Data for these periods were analyzed separately to account for changes in streamflow because of 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 and median monthly and annual discharges, magnitude and probability of exceedance of annual instantaneous peak flows, durations of daily mean flow, magnitude and probability of nonexceedance of annual low flows, and magnitude and probability of nonexceedance of seasonal low flows.

  1. 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.

  2. 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.

  3. 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.

    2013-12-01

    ⪉bel{sec:abstract} Snow surface temperature is a key control on energy exchanges at the snow surface, particularly net longwave radiation and turbulent energy fluxes. The snow surface temperature is in turn controlled by the balance between various external fluxes and the conductive heat flux, internal to the snowpack. 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 examine the parameterization of snow surface temperature in single layer snowmelt models from the perspective of heat conduction into a semi-infinite medium. We evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We also 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. These tests compare modeled and measured snow surface temperature, snow energy content, snow water equivalent, and snowmelt outflow. We found that with these refinements the model is able to better represent the snowpack energy balance and

  4. Comparison of Temperature-Index Snowmelt Models for Use within an Operational Water Quality Model.

    PubMed

    Watson, Brett M; Putz, Gordon

    2014-01-01

    The accurate prediction of snowmelt runoff is a critical component of integrated hydrological and water quality models in regions where snowfall constitutes a significant portion of the annual precipitation. In cold regions, the accumulation of a snowpack and the subsequent spring snowmelt generally constitutes a major proportion of the annual water yield. Furthermore, the snowmelt runoff transports significant quantities of sediment and nutrients to receiving streams and strongly influences downstream water quality. Temperature-index models are commonly used in operational hydrological and water quality models to predict snowmelt runoff. Due to their simplicity, computational efficiency, low data requirements, and ability to consistently achieve good results, numerous temperature-index models of varying complexity have been developed in the past few decades. The objective of this study was to determine how temperature-index models of varying complexity would affect the performance of the water quality model SWAT (a modified version of SWAT that was developed for watersheds dominated by boreal forest) for predicting runoff. Temperature-index models used by several operational hydrological models were incorporated into SWAT. Model performance was tested on five watersheds on the Canadian Boreal Plain whose hydrologic response is dominated by snowmelt runoff. The results of this study indicate that simpler temperature-index models can perform as well as more complex temperature-index models for predicting runoff from the study watersheds. The outcome of this study has important implications because the incorporation of simpler temperature-index snowmelt models into hydrological and water quality models can lead to a reduction in the number of parameters that need to be optimized without sacrificing predictive accuracy.

  5. 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

  6. Using the nonlinear aquifer storage-discharge relationship to simulate the base flow of glacier- and snowmelt-dominated basins in northwest China

    NASA Astrophysics Data System (ADS)

    Gan, R.; Luo, Y.

    2013-09-01

    Base flow is an important component in hydrological modeling. This process is usually modeled by using the linear aquifer storage-discharge relation approach, although the outflow from groundwater aquifers is nonlinear. To identify the accuracy of base flow estimates in rivers dominated by snowmelt and/or glacier melt in arid and cold northwestern China, a nonlinear storage-discharge relationship for use in SWAT (Soil Water Assessment Tool) modeling was developed and applied to the Manas River basin in the Tian Shan Mountains. Linear reservoir models and a digital filter program were used for comparisons. Meanwhile, numerical analysis of recession curves from 78 river gauge stations revealed variation in the parameters of the nonlinear relationship. It was found that the nonlinear reservoir model can improve the streamflow simulation, especially for low-flow period. The higher Nash-Sutcliffe efficiency, logarithmic efficiency, and volumetric efficiency, and lower percent bias were obtained when compared to the one-linear reservoir approach. The parameter b of the aquifer storage-discharge function varied mostly between 0.0 and 0.1, which is much smaller than the suggested value of 0.5. The coefficient a of the function is related to catchment properties, primarily the basin and glacier areas.

  7. 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.

  8. 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.

  9. 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.

  10. Lack of bioaccumulation of metals by Elliptio complanata (Bivalvia) during acidic snowmelt in three south-central Ontario streams

    SciTech Connect

    Servos, M.R.; Malley, D.F.; Mackie, G.L.; LaZerte, B.D.

    1987-05-01

    Depression of pH and elevation of metals during spring snowmelt may be widespread. However, because of the episodic nature of these events they are very difficult to measure or even detect. Sampling of snowmelt at regular intervals of only a few days, may not be adequate to detect short-term variations in pH and metal concentrations. The objective of the present study was to determine the feasibility of using biomonitoring to detect short-term changes in concentration or bioavailability of metals (Al, Zn, Cd) during spring snowmelt. Unionid clams, (Elliptio complanata) were held in three south-central Ontario streams during the spring snowmelt period of 1982. The gill tissues accumulate metals more readily than other tissues and thus are better biomonitors of available metals than whole body concentrations of these elements. Therefore, the concentration of metals in soft tissues (gill, body, foot) were compared separately to the stream water chemistry during snowmelt.

  11. 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

  12. Streamflow Simulations of the Terrestrial Arctic Regime

    NASA Astrophysics Data System (ADS)

    Su, F.; Adam, J.; Bowling, L.; Lettenmaier, D.

    2003-12-01

    Runoff from the Arctic terrestrial drainage system represents about two-thirds of the net flux of freshwater to the Arctic Ocean. Both the amount and the timing of freshwater inflow to the ocean systems are important to ocean circulation, salinity, and sea ice dynamics. In this study, the Variable Infiltration Capacity (VIC) model is used to simulate runoff and streamflow from the pan-Arctic terrestrial domain from 1979 to 1999. The VIC model is a grid-based land surface scheme designed both for inclusion in GCMs, and for use as a stand-alone macroscale hydrological model. The key elements of the model that are particularly relevant to high latitude implementations include a two-layer energy balance snow model, a frozen soil/permafrost algorithm, a blowing snow model, and a lakes and wetlands model, none of which have previously been applied over the entire pan-Arctic domain. The model was applied over a 100kmx100km EASE grid mesh with full energy balance (closure for surface skin temperature) at a time step of 3 hours. A river network was developed for the model grid mesh and a routing scheme was run offline which takes daily VIC surface and subsurface runoff as input to obtain model simulated streamflows at the outlets of selected study basins. The forcing data, soil, and vegetation parameters needed by the VIC are described and evaluated, along with calibration issues. The VIC streamflow simulations for the Lena, Ob, and Mackenzie watersheds are compared with observations. For the 20-year study period, an estimate is provided of the mean freshwater flux to the Arctic and its spatial distribution, and is compared with previous estimates.

  13. Streamflow and water well responses to earthquakes.

    PubMed

    Montgomery, David R; Manga, Michael

    2003-06-27

    Earthquake-induced crustal deformation and ground shaking can alter stream flow and water levels in wells through consolidation of surficial deposits, fracturing of solid rocks, aquifer deformation, and the clearing of fracture-filling material. Although local conditions affect the type and amplitude of response, a compilation of reported observations of hydrological response to earthquakes indicates that the maximum distance to which changes in stream flow and water levels in wells have been reported is related to earthquake magnitude. Detectable streamflow changes occur in areas within tens to hundreds of kilometers of the epicenter, whereas changes in groundwater levels in wells can occur hundreds to thousands of kilometers from earthquake epicenters.

  14. Unorganized machines for seasonal streamflow series forecasting.

    PubMed

    Siqueira, Hugo; Boccato, Levy; Attux, Romis; Lyra, Christiano

    2014-05-01

    Modern unorganized machines--extreme learning machines and echo state networks--provide an elegant balance between processing capability and mathematical simplicity, circumventing the difficulties associated with the conventional training approaches of feedforward/recurrent neural networks (FNNs/RNNs). This work performs a detailed investigation of the applicability of unorganized architectures to the problem of seasonal streamflow series forecasting, considering scenarios associated with four Brazilian hydroelectric plants and four distinct prediction horizons. Experimental results indicate the pertinence of these models to the focused task.

  15. Streamflow of 2014: water year summary

    USGS Publications Warehouse

    Jian, Xiaodong; Wolock, David M.; Jenter, Harry L.; Brady, Steve

    2015-01-01

    In the summary, reference is made to the term “runoff,” which is the depth to which a river basin or other geographic area, such as a State, would be covered with water if all the streamflow within the area during a specified time period was uniformly distributed over the area. Runoff can also be used to quantify the magnitude of water flowing through rivers and streams in measurement units that can be compared from one area of the Nation to another.

  16. 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.

  17. Streamflow Characteristics of Streams in Southeastern Afghanistan

    USGS Publications Warehouse

    Vining, Kevin C.

    2010-01-01

    Statistical summaries of streamflow data for all historical streamgaging stations that have available data in the southeastern Afghanistan provinces of Ghazni, Khost, Logar, Paktya, and Wardak, and a portion of Kabul Province are presented in this report. The summaries for each streamgaging station include a station desciption, table of statistics of monthly and annual mean discharges, table of monthly and annual flow duration, table of probability of occurrence of annual high discharges, table of probability of occurrence of annual low discharges, table of annual peak discharge and corresponding gage height for the period of record, and table of monthly and annual mean discharges for the period of record.

  18. 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.

  19. 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.

  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. [Soil infiltration of snowmelt water in the southern Gurbantunggut Desert, Xinjiang, China].

    PubMed

    Hu, Shun-jun; Chen, Yong-bao; Zhu, Hai

    2015-04-01

    Soil infiltration of snow-melt water is an important income item of water balance in arid desert. The soil water content in west slope, east slope and interdune of sand dune in the southern Gurbantunggut Desert was monitored before snowfall and after snow melting during the winters of 2012-2013 and 2013-2014. According to the principle of water balance, soil infiltration of snow-melt in the west slope, east slope, interdune and landscape scale was calculated, and compared with the results measured by cylinder method. The results showed that the soil moisture recharge from unfrozen layer of unsaturated soil to surface frozen soil was negligible because the soil moisture content before snowfall was lower, soil infiltration of snow-melt water was the main source of soil water of shallow soil, phreatic water did not evaporate during freezing period, and did not get recharge after the snow melting. Snowmelt water in the west slope, east slope, interdune and landscape scale were 20-43, 27-43, 32-45, 26-45 mm, respectively.

  2. 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.

  3. 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

  4. AMSR-E Algorithm for Snowmelt Onset Detection in Subarctic Heterogeneous Terrain

    NASA Astrophysics Data System (ADS)

    Apgar, J. D.; Ramage, J. M.; McKenney, R. A.; Kopczynski, S. E.; Haight, S. L.; Maltais, P.

    2006-12-01

    Snowmelt onset in the mixed terrain of the upper Yukon River basin, Canada, can be derived from brightness temperatures (Tb) obtained by the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) on NASA's Aqua satellite. AMSR-E, with a resolution of 14 x 8 km2 for the 36.5 GHz frequency and two to four observations per day, improves upon the twice-daily coverage (EASE-Grid) and 37 x 28 km2 spatial resolution of the Special Sensor Microwave Imager (SSM/I). The onset of melt within a snowpack causes an increase in the daytime 36.5 GHz vertically polarized Tb as well as a shift to high diurnal amplitude variations (DAV) as the snow melts during the day and refreezes at night. The higher temporal and spatial resolutions, as well as the timing of data acquisition, make AMSR-E more sensitive than SSM/I to sub-daily Tb oscillations, resulting in DAV that show a greater daily range compared to SSM/I. Using ground- based surface temperature and snowpack wetness to verify satellite interpretations, the snowmelt thresholds of Tb > 246 K and DAV > ±10 K developed for use with SSM/I have been adjusted for detecting melt onset with AMSR-E to Tb > 252 K and DAV > ±18 K. AMSR-E derived snowmelt onset correspond with SSM/I observations in the small subarctic Wheaton River basin (~60°08'05"N, ~134°53'45"W) through the 2004 and 2005 spring transitions. Snowpack wetness measurements collected in the Wheaton basin during the spring of 2005 relate well with temporally-corresponding AMSR-E Tb and the established snowmelt thresholds. The enhanced resolution of AMSR-E is more effective than SSM/I at delineating both spatial and temporal snowmelt dynamics in the heterogeneous terrain of the upper Yukon River basin. The use of this AMSR-E snowmelt onset algorithm in other areas of the subarctic will ultimately allow for a more thorough examination of the impact of spring snowmelt upon basin hydrology and regional climate.

  5. 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

  6. Spatial and Temporal Distribution of Water in Snow and Soil During Spring Snowmelt in a Small Watershed in Northwest Colorado

    NASA Astrophysics Data System (ADS)

    Webb, R.; Fassnacht, S. R.; Gooseff, M. N.

    2015-12-01

    The melting of a winter snowpack will often include spatially and temporally variable infiltration across the soil-snow-interface prior to generating streamflow, groundwater recharge, or plant production. During spring snowmelt, moisture distribution is largely driven by hydraulic gradients under variably saturated conditions within the soil and snowpack. In complex mountainous terrain, the variable melt rates across the landscape due to slope, aspect, and landcover add further irregularities to this dynamic system. The aim of this research is gain insight into the distribution of water both within and below a melting snowpack during spring at Dry Lake Study Site near Steamboat Springs, Colorado. This site is a small (0.2 km2) subalpine watershed with a seasonally persistent snowpack each year. Intensive field surveys were conducted to collect snow water equivalent and soil moisture distribution during April and May of 2014 and 2015. Results show the variability in soil moisture consistent with similar studies, suggesting soil moisture distribution follows a similar trend as accumulation of snow depth in relation to topographic and canopy influences. The soil moisture on south facing hillslopes tended to be less than north facing slopes, with flat terrain holding near saturated conditions, particularly in locations with thick layers of organic matter. However, of notable interest is the distribution of snow water equivalent during melt. Early in the melt period at the base of some hillslopes snow water equivalent increased as locations directly upslope decreased suggesting movement of moisture within the snowpack during the transitional period from winter to spring. The hydraulic conductivity of snow has been shown to be greater than that of common soils, suggesting that the timing of water movement from a snowpack to stream will be shortened when considering the flow through the snow layers compared to shallow groundwater on hillslopes. These results have

  7. Importance of snowmelt-derived fluxes on the groundwater flow in a high elevation meadow (Invited)

    NASA Astrophysics Data System (ADS)

    Lowry, C.; Loheide, S. P.; Deems, J. S.; Moore, C. E.; Lundquist, J. D.

    2010-12-01

    In order to manage or restore riparian ecosystems in high elevation environments, under both current and future climatic conditions, we must have an understanding of both stream flow and groundwater dynamics. Seasonal changes in both stream flow and water table fluctuations in these environments are dependent on snowmelt-derived flux entering riparian zones from the larger watershed. Without reliable data, from field observations or numerical modeling, there is little chance of accurately quantifying changes in water table dynamics, surface inundation, soil moisture or stream stage, which are critical to riparian vegetation within these systems. In the work presented here, we show the impact of snowmelt-derived groundwater flux from the surrounding hillslopes on water table dynamics in Tuolumne Meadows, which is located in the Sierra Nevada Mountains of California, USA. Results show the importance of a combination of fluxes at the hillslope boundaries, snowmelt within the meadow and changes in the stream stage on water levels within the meadow. These results also demonstrate the importance of timing of groundwater flux entering the meadow as a result of spring snowmelt, which was observed to vary over 20 days based on the location, aspect, and local geology of the contributing area within the larger watershed. Identifying temporal and spatial variability in flux entering the meadow is necessary in order to simulate changes in water levels within the meadow. Caution must be taken when linking watershed scale models to local meadow scale models as results can vary significantly based on the temporal and spatial scales at which boundary fluxes are lumped. Without a clear hydrologic representation of snowmelt on the surrounding hillslopes, it is difficult to simulate groundwater dynamics within these riparian ecosystems with the accuracy necessary for understanding ecosystem response.

  8. Sources of nitrate in snowmelt discharge: Evidence from water chemistry and stable isotopes of nitrate

    USGS Publications Warehouse

    Piatek, K.B.; Mitchell, M.J.; Silva, S.R.; Kendall, C.

    2005-01-01

    To determine whether NO3- concentration pulses in surface water in early spring snowmelt discharge are due to atmospheric NO 3-, we analyzed stream ??15N-NO 3- and ??18O-NO3- values between February and June of 2001 and 2002 and compared them to those of throughfall, bulk precipitation, snow, and groundwater. Stream total Al, DOC and Si concentrations were used to indicate preferential water flow through the forest floor, mineral soil, and ground water. The study was conducted in a 135-ha subcatchment of the Arbutus Watershed in the Huntington Wildlife Forest in the Adirondack Region of New York State, U.S.A. Stream discharge in 2001 increased from 0.6 before to 32.4 mm day-1 during snowmelt, and element concentrations increased from 33 to 71 ??mol L-1 for NO3-, 3 to 9 ??mol L-1 for total Al, and 330 to 570 ??mol L-1 for DOC. Discharge in 2002 was variable, with a maximum of 30 mm day-1 during snowmelt. The highest NO3-, Al, and DOC concentrations were 52, 10, and 630 ??mol L -1, respectively, and dissolved Si decreased from 148 ??mol L -1 before to 96 ??mol L-1 during snowmelt. Values of ??15N and ??18O of NO3- in stream water were similar in both years. Stream water, atmospherically- derived solutions, and groundwaters had overlapping ??15N- NO3- values. In stream and ground water, ??18O-NO3- values ranged from +5.9 to +12.9??? and were significantly lower than the +58.3 to +78.7??? values in atmospheric solutions. Values of ??18O-NO3- indicating nitrification, increase in Al and DOC, and decrease in dissolved Si concentrations indicating water flow through the soil suggested a dilution of groundwater NO3- by increasing contributions of forest floor and mineral soil NO3- during snowmelt. ?? Springer 2005.

  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. 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....

  11. Streamflow of 2013: water year summary

    USGS Publications Warehouse

    Jian, Xiaodong; Wolock, David M.; Lins, Harry F.; Brady, Steve

    2014-01-01

    The maps and graphs in this summary describe streamflow conditions for water year 2013 (October 1, 2012, to September 30, 2013) in the context of the 84-year period from 1930 through 2013, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey’s (USGS) National Water Information System ( http://waterdata.usgs.gov/nwis/). The period 1930–2013 was used because, prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country. In the summary, reference is made to the term “runoff,” which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a specified time period was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation’s rivers and streams in measurement units that can be compared from one area to another.

  12. 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

  13. 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

  14. Assessment of river water quality during snowmelt and base flow periods in two catchment areas with different land use.

    PubMed

    Woli, Krishna Prasad; Hayakawa, Atsushi; Kuramochi, Kanta; Hatano, Ryusuke

    2008-02-01

    River water quality was evaluated with respect to eutrophication and land use during spring snowmelt and summer base flow periods in Abashiri (mixed cropland-livestock farming) and Okoppe (grassland-based dairy cattle farming), eastern Hokkaido, Japan. Water from rivers and tributaries was sampled during snowmelt and summer base flow periods in 2005, and river flow was measured. Total N (TN), NO(3)-N, and Si concentrations were determined using standard methods. Total catchment and upland areas for each sampling site were determined with ArcGIS hydrology modeling software and 1:25,000-scale digital topographic maps. Specific discharge was significantly higher during snowmelt than during base flow. In both areas, TN concentrations increased, whereas Si concentrations decreased, with increased specific discharge, and were significantly higher during snowmelt. The Si:TN mole ratio decreased to below or close to the threshold value for eutrophication (2.7) in one-third of sites during snowmelt. River NO(3)-N concentrations during base flow were significantly and positively correlated with the proportion of upland fields in the catchment in both the Abashiri (r = 0.88, P < 0.001) and Okoppe (r = 0.43, P < 0.01) areas. However, the regression slope, defined as the impact factor (IF) of water quality, was much higher in Abashiri (0.025) than in Okoppe (0.0094). The correlations were also significantly positive during snowmelt in both areas, but IF was four to eight times higher during snowmelt than during base flow. Higher discharge of N from upland fields and grasslands during snowmelt and the resulting eutrophication in estuaries suggest that nutrient discharge during snowmelt should be taken into account when assessing and monitoring the annual loss of nutrients from agricultural fields.

  15. 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

  16. 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

  17. Statistical summaries of New Jersey streamflow records

    USGS Publications Warehouse

    Laskowski, Stanley L.

    1970-01-01

    In 1961 the U.S. Geological Survey prepared a report which was published by the State of New Jersey as Water Resources Circular 6, "New Jersey Streamflow Records analyzed with Electronic Computer" by Miller and McCall. Basic discharge data for periods of record through 1958 were analyzed for 59 stream-gaging stations in New Jersey and flow-duration, low-flow, and high-flow tables were presented. The purpose of the current report is to update and expand Circular 6 by presenting, with a few meaningful statistics and tables, the bulk of the information that may be obtained from the mass of streamflow records available. The records for 79 of approximately 110 stream-gaging stations presently or previously operated in New Jersey, plus records for three stations in Pennsylvania, and one in New York are presented in summarized form. In addition to inclusing a great number of stations in this report, more years of record and more tables are listed for each station. A description of the station, three arrangements of data summarizing the daily flow records and one table listing statistics of the monthly mean flows are provided. No data representing instantaneous extreme flows are given. Plotting positions for the three types of curves describing the characteristics of daily discharge are listed for each station. Statistical parameters are also presented so that alternate curves may be drawn. All stations included in this report have 5 or more years of record. The data presented herein are based on observed flow past the gaging station. For any station where the observed flow is affected by regulation or diversion, a "Remarks" paragraph, explaining the possible effect on the data, is included in the station description. Since any streamflow record is a sample in time, the data derived from these records can provide only a guide to expected future flows. For this reason the flow records are analyzed by statistical techniques, and the magnitude of sampling errors should be

  18. 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

  19. Streamflow and water-quality trends of the Rio Chama and Rio Grande, northern and central New Mexico, water years 1985 to 2002

    USGS Publications Warehouse

    Langman, Jeff B.; Nolan, Emma O.

    2005-01-01

    The City of Albuquerque plans to divert San Juan-Chama Project water from the Rio Grande for potable water use. This report examines streamflow and water-quality trends in the Rio Chama and the Rio Grande for water years 1985 to 2002 following the implementation of reservoir storage agreements in northern and central New Mexico. Streamflow/water-quality stations used for this study include the Rio Grande stations of Taos, Otowi, San Felipe, and Albuquerque and the Rio Chama station of Chamita. Water years 1985 to 2002 were a period of larger than average precipitation and streamflow compared to the stations. historical averages. Annual precipitation and streamflow trended downward during the study period because of a drought during 1999 to 2002. Streamflow in the Rio Chama and Rio Grande was divided into three distinct seasonal periods that corresponded to natural and anthropogenic influences: fall/winter baseflow (November through February), snowmelt runoff (March through June), and the irrigation/monsoon (July through October) seasons. A calcium bicarbonate water type was evident at all study area stations on the Rio Chama and Rio Grande. Specific conductance increased downstream, but alkalinity and pH did not substantially change in the downstream direction. Nearly all nitrogen and phosphorous concentrations were less than 1 milligram per liter for all stations. Median trace-element concentrations and maximum radionuclide concentrations did not exceed drinking-water standards. Anthropogenic compounds were infrequently detected in the Rio Chama and Rio Grande, and concentrations did not exceed drinking-water standards. Water quality in the Rio Chama and Rio Grande varied spatially and temporally during water years 1985 to 2002. Specific conductance increased downstream in the Rio Grande during the fall/winter baseflow and snowmelt runoff seasons but was similar at the Taos, Otowi, and San Felipe stations during the irrigation/monsoon season. This similarity was a

  20. 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

  1. Catchment classification and similarity using correlation in streamflow time series

    NASA Astrophysics Data System (ADS)

    Fleming, B.; Archfield, S. A.

    2012-12-01

    Catchment classification is an important component of hydrologic analyses, particularly for linking changes in ecological integrity to streamflow alteration, transferring time series or model parameters from gauged to ungauged locations, and as a way to understand the similarity in the response of catchments to change. Metrics of similarity used in catchment classification have ranged from aggregate catchment properties such as geologic or climate characteristics to variables derived from the daily streamflow hydrograph; however, no one set of classification variables can fully describe similarity between catchments as the variables used for such assessments often depend on the question being asked. We propose an alternative method based on similarity for hydrologic classification: correlation between the daily streamflow time series. If one assumes that the streamflow signal is the integrated response of a catchment to both climate and geology, then the strength of correlation in streamflow between two catchments is a measure of the strength of similarity in hydrologic response between those two catchments. Using the nonparametric Spearman rho correlation coefficient between streamflow time series at 54 unregulated and unaltered streamgauges in the mid-Atlantic United States, we show that correlation is a parsimonious classification metric that results in physically interpretable classes. Using the correlation between the deseasonalized streamflow time series and reclassifying the streamgauges, we also find that seasonality plays an important role in understanding catchment flow dynamics, especially those that can be linked to ecological response and similarity although not to a large extent in this study area.

  2. 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.

  3. Forecast-skill-based simulation of streamflow forecasts

    NASA Astrophysics Data System (ADS)

    Zhao, Tongtiegang; Zhao, Jianshi

    2014-09-01

    Streamflow forecasts are updated periodically in real time, thereby facilitating forecast evolution. This study proposes a forecast-skill-based model of forecast evolution that is able to simulate dynamically updated streamflow forecasts. The proposed model applies stochastic models that deal with streamflow variability to generate streamflow scenarios, which represent cases without forecast skill of future streamflow. The model then employs a coefficient of prediction to determine forecast skill and to quantify the streamflow variability ratio explained by the forecast. By updating the coefficients of prediction periodically, the model efficiently captures the evolution of streamflow forecast. Simulated forecast uncertainty increases with increasing lead time; and simulated uncertainty during a specific future period decreases over time. We combine the statistical model with an optimization model and design a hypothetical case study of reservoir operation. The results indicate the significance of forecast skill in forecast-based reservoir operation. Shortage index reduces as forecast skill increases and ensemble forecast outperforms deterministic forecast at a similar forecast skill level. Moreover, an effective forecast horizon exists beyond which more forecast information does not contribute to reservoir operation and higher forecast skill results in longer effective forecast horizon. The results illustrate that the statistical model is efficient in simulating forecast evolution and facilitates analysis of forecast-based decision making.

  4. 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.

  5. 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.

  6. Modeled future peak streamflows in four coastal Maine rivers

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Dudley, Robert W.

    2013-01-01

    To safely and economically design bridges and culverts, it is necessary to compute the magnitude of peak streamflows that have specified annual exceedance probabilities (AEPs). Annual precipitation and air temperature in the northeastern United States are, in general, projected to increase during the 21st century. It is therefore important for engineers and resource managers to understand how peak flows may change in the future. This report, prepared in cooperation with the Maine Department of Transportation (MaineDOT), presents modeled changes in peak flows at four basins in coastal Maine on the basis of projected changes in air temperature and precipitation. To estimate future peak streamflows at the four basins in this study, historical values for climate (temperature and precipitation) in the basins were adjusted by different amounts and input to a hydrologic model of each study basin. To encompass the projected changes in climate in coastal Maine by the end of the 21st century, air temperatures were adjusted by four different amounts, from -3.6 degrees Fahrenheit (ºF) (-2 degrees Celsius (ºC)) to +10.8 ºF (+6 ºC) of observed temperatures. Precipitation was adjusted by three different percentage values from -15 percent to +30 percent of observed precipitation. The resulting 20 combinations of temperature and precipitation changes (includes the no-change scenarios) were input to Precipitation-Runoff Modeling System (PRMS) watershed models, and annual daily maximum peak flows were calculated for each combination. Modeled peak flows from the adjusted changes in temperature and precipitation were compared to unadjusted (historical) modeled peak flows. Annual daily maximum peak flows increase or decrease, depending on whether temperature or precipitation is adjusted; increases in air temperature (with no change in precipitation) lead to decreases in peak flows, whereas increases in precipitation (with no change in temperature) lead to increases in peak flows. As

  7. 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.

  8. 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

  9. Seasonal streamflow forecasting by conditioning climatology with precipitation indices

    NASA Astrophysics Data System (ADS)

    Crochemore, Louise; Ramos, Maria-Helena; Pappenberger, Florian; Perrin, Charles

    2017-03-01

    Many fields, such as drought-risk assessment or reservoir management, can benefit from long-range streamflow forecasts. Climatology has long been used in long-range streamflow forecasting. Conditioning methods have been proposed to select or weight relevant historical time series from climatology. They are often based on general circulation model (GCM) outputs that are specific to the forecast date due to the initialisation of GCMs on current conditions. This study investigates the impact of conditioning methods on the performance of seasonal streamflow forecasts. Four conditioning statistics based on seasonal forecasts of cumulative precipitation and the standardised precipitation index were used to select relevant traces within historical streamflows and precipitation respectively. This resulted in eight conditioned streamflow forecast scenarios. These scenarios were compared to the climatology of historical streamflows, the ensemble streamflow prediction approach and the streamflow forecasts obtained from ECMWF System 4 precipitation forecasts. The impact of conditioning was assessed in terms of forecast sharpness (spread), reliability, overall performance and low-flow event detection. Results showed that conditioning past observations on seasonal precipitation indices generally improves forecast sharpness, but may reduce reliability, with respect to climatology. Conversely, conditioned ensembles were more reliable but less sharp than streamflow forecasts derived from System 4 precipitation. Forecast attributes from conditioned and unconditioned ensembles are illustrated for a case of drought-risk forecasting: the 2003 drought in France. In the case of low-flow forecasting, conditioning results in ensembles that can better assess weekly deficit volumes and durations over a wider range of lead times.

  10. 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.

  11. Simulation of snowmelt in a subarctic spruce woodland: 2. Open woodland model

    NASA Astrophysics Data System (ADS)

    Giesbrecht, Mark A.; Woo, Ming-Ko

    2000-08-01

    A model is presented to simulate snowmelt in a subarctic woodland using a Geographic Information System to express the spatial distribution of snow and the pattern of trees and their shifting shadows during the day. The woodland is distinguished into several zone types, including openings under the Sun and in the shade, zones beneath the tree canopy, and the tree trunks. Meteorological data obtained at an open site are transposed to each zone for the calculation of melt rates. The wooded experimental plot is subdivided into 2×2 m2 grid cells, each with different fractional areas occupied by various zone types. Melt rates at each cell are obtained by weighting the zonal melt with these fractional areas. Despite some limitations the model provides a spatial dimension to snowmelt in the woodland and yields mean melt values that enhance the representation of the forest melt conditions conventionally obtained using calculations for single points.

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

    USGS Publications Warehouse

    Ries(compiler), Kernell G.; 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.

    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

  13. Mercury Transport During Snowmelt in Three Mountain Watersheds in Northern Utah, USA

    NASA Astrophysics Data System (ADS)

    Packer, B. N.; Carling, G. T.; Tingey, D. G.

    2015-12-01

    Mercury (Hg) transport during snowmelt is widely recognized as a significant source of Hg to high elevation lakes and streams. However, it is not well understood to what extent Hg is associated with suspended sediment versus dissolved organic matter during snowmelt runoff. To investigate Hg transport during snowmelt, we collected samples for filtered and unfiltered total Hg (THg) and dissolved organic carbon (DOC) in snowpack and snowmelt runoff across three snow-dominated watersheds in northern Utah: Logan River, Provo River, and Little Cottonwood Creek. The watersheds were selected to cover a range of geologic and hydrologic conditions typical of the Rocky Mountain region. Initial results show that snowpack THg concentrations were similar across the watersheds (0.87 - 1.69 ng/L) but river THg concentrations were highly variable. The Provo River showed the highest THg concentrations approaching 6 ng/L during peak flows, whereas maximum THg concentrations in the Logan River were <2 ng/L. Little Cottonwood Creek showed intermediate THg concentrations. THg and DOC showed strong positive correlation in the Provo River (R2=0.68) but were not correlated in the Logan River (R2=0.04). Notably, the Provo River showed the highest fraction of "dissolved" THg (calculated as the fraction of filtered/unfiltered concentration) averaging 75% compared with the other sites where the "dissolved" fraction was <45%. These results suggest that the majority of THg is transported in association with DOC in the Provo River but is more strongly associated with suspended sediments in the Logan River and Little Cottonwood Creek. These findings have implications for understanding Hg cycling in the Provo River watershed where Jordanelle Reservoir has fish consumption advisories due elevated Hg concentrations. The dissolved load of THg, possibly associated with DOC, is likely methylated in Jordanelle Reservoir where it bio-accumulates up the food web.

  14. 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.

  15. Forest Harvesting Impacts on Attributes of the Flow Regime in Snowmelt Regions

    NASA Astrophysics Data System (ADS)

    Green, K.; Alila, Y.

    2014-12-01

    Recent studies have revealed how forest cover removal can alter the frequency and magnitude of annual peak flows. However, to fully understand the impacts of land cover changes on stream channels, it is necessary to examine how multiple attributes of the flow regime are affected. Changes in the frequency and duration of peaks over threshold (PoT) discharge for sediment mobilization has the potential to alter the dynamics of bedload mobility and channel form in alluvial gravel-bed streams. A meta-analysis investigation of changes in the duration and number of PoT in four snowmelt catchments of western North America contributes towards a comprehensive understanding of the influence of harvesting on the snowmelt flow regime. Analysis results reveal that harvesting causes the duration and number of PoT of snowmelt peak flows to increase and that these increases are generally greater for larger flood quantiles. Such a response indicates that, following harvesting, the hydrograph in all four catchments has become more responsive during the freshet period. In addition harvesting has resulted in increases in the total volume (i.e. duration) of flood peaks so that discharge remains elevated above specific thresholds for longer periods of time. The meta-analysis results suggest that physical basin characteristics including percentage of alpine area, slope aspect, and gradient, elevation and watershed size all play a role in catchment scale response to harvesting-related increases in flood duration and PoT. In snow environments alterations to the flow regime due to forest removal are likely to persist for many decades until sufficient forest regeneration restores stand level processes of snow accumulation and snowmelt.

  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. Nitrogen dynamics in two high elevation catchments during spring snowmelt 1996, Rocky Mountains, Colorado

    NASA Astrophysics Data System (ADS)

    Heuer, Kristi; Brooks, Paul D.; Tonnessen, Kathy A.

    1999-10-01

    Snowpack, soil, soil leachate, and streamwater samples were analyzed for inorganic nitrogen (N) to quantify the net effect of soil processes on N export during spring snowmelt. The two catchments used for this work, Snake River and Deer Creek, are located in Summit County, Colorado and range in elevation from 3350 to 4120 m. Atmospheric N loading to the snowpack, 88 mg N m-2 (=0·88 kg N ha-1), was representative of low N deposition sites in the Rocky Mountains. Potentially mobile inorganic N in soil, 1252 to 1868 mg N m-2, was much greater than N inputs from snow. During spring snowmelt, nitrate (NO) leachate from alpine soil, 702 mg N m-2, was significantly greater than from sub-alpine forest and meadow soils (p<0·001). This pattern in soil leachate was consistent with streamwater N concentrations in Deer Creek, indicating the importance of soil processes in regulating N export from these high elevation catchments. Soils may function as sources or sinks of N during spring snowmelt; alpine soils were a significant source of N to the stream, while sub-alpine soils were possible N sinks.

  18. 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.

  19. 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.

  20. 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.

  1. Improved snowmelt simulations with a canopy model forced with photo-derived direct beam canopy transmissivity

    NASA Astrophysics Data System (ADS)

    Musselman, Keith N.; Molotch, Noah P.; Margulis, Steven A.; Lehning, Michael; Gustafsson, David

    2012-10-01

    The predictive capacity of a physically based snow model to simulate point-scale, subcanopy snowmelt dynamics is evaluated in a mixed conifer forest, southern Sierra Nevada, California. Three model scenarios each providing varying levels of canopy structure detail were tested. Simulations of three water years initialized at locations of 24 ultrasonic snow depth sensors were evaluated against observations of snow water equivalent (SWE), snow disappearance date, and volumetric soil water content. When canopy model parameters canopy openness and effective leaf area index were obtained from satellite and literature-based sources, respectively, the model was unable to resolve the variable subcanopy snowmelt dynamics. When canopy parameters were obtained from hemispherical photos, the improvements were not statistically significant. However, when the model was modified to accept photo-derived time-varying direct beam canopy transmissivity, the error in the snow disappearance date was reduced by as much as one week and positive and negative biases in melt-season SWE and snow cover duration were significantly reduced. Errors in the timing of soil meltwater fluxes were reduced by 11 days on average. The optimum aggregated temporal model resolution of direct beam canopy transmissivity was determined to be 30 min; hourly averages performed no better than the bulk canopy scenarios and finer time steps did not increase overall model accuracy. The improvements illustrate the important contribution of direct shortwave radiation to subcanopy snowmelt and confirm the known nonlinear melt behavior of snow cover.

  2. 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

  3. 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.

  4. Critical factors affecting field-scale losses of nitrogen and phosphorus in spring snowmelt runoff in the canadian prairies.

    PubMed

    Liu, Kui; Elliott, Jane A; Lobb, David A; Flaten, Don N; Yarotski, Jim

    2013-01-01

    A long-term, field-scale study in southern Manitoba, Canada, was used to identify the critical factors controlling yearly transport of nitrogen (N) and phosphorus (P) by snowmelt runoff. Flow monitoring and water sampling for total and dissolved N and P were performed at the edge of field. The flow-weighted mean concentrations and loads of N and P for the early (the first half of yearly total volume of snowmelt runoff), late (the second half of yearly total volume of snowmelt runoff), and yearly snowmelt runoff were calculated as response variables. A data set of management practices, weather variables, and hydrologic variables was generated and used as predictor variables. Partial least squares regression analysis indicated that critical factors affecting the water chemistry of snowmelt runoff depended on the water quality variable and stage of runoff. Management practices within each year, such as nitrogen application rate, number of tillage passes, and residue burial ratio, were critical factors for flow-weighted mean concentration of N, but not for P concentration or nutrient loads. However, the most important factors controlling nutrient concentrations and loads were those related to the volume of runoff, including snow water equivalent, flow rate, and runoff duration. The critical factors identified for field-scale yearly snowmelt losses provide the basis for modeling of nutrient losses in southern Manitoba and potentially throughout areas with similar climate in the northern Great Plains region, and will aid in the design of effective practices to reduce agricultural nonpoint nutrient pollution in downstream waters.

  5. 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

  6. Streamflow Duration Assessment Method for the Pacific Northwest

    EPA Pesticide Factsheets

    The Streamflow Duration Assessment Method for the Pacific Northwest is a scientific tool developed by EPA and the U.S. Army Corps of Engineers to provide a rapid assessment framework to distinguish between ephemeral, intermittent and perennial streams.

  7. Regionalization of harmonic-mean streamflows in Kentucky

    USGS Publications Warehouse

    Martin, Gary R.; Ruhl, Kevin J.

    1993-01-01

    Harmonic-mean streamflow (Qh), defined as the reciprocal of the arithmetic mean of the reciprocal daily streamflow values, was determined for selected stream sites in Kentucky. Daily mean discharges for the available period of record through the 1989 water year at 230 continuous record streamflow-gaging stations located in and adjacent to Kentucky were used in the analysis. Periods of record affected by regulation were identified and analyzed separately from periods of record unaffected by regulation. Record-extension procedures were applied to short-term stations to reducetime-sampling error and, thus, improve estimates of the long-term Qh. Techniques to estimate the Qh at ungaged stream sites in Kentucky were developed. A regression model relating Qh to total drainage area and streamflow-variability index was presented with example applications. The regression model has a standard error of estimate of 76 percent and a standard error of prediction of 78 percent.

  8. Georgia's Surface-Water Resources and Streamflow Monitoring Network, 2006

    USGS Publications Warehouse

    Nobles, Patricia L.; ,

    2006-01-01

    The U.S. Geological Survey (USGS) network of 223 real-time monitoring stations, the 'Georgia HydroWatch,' provides real-time water-stage data, with streamflow computed at 198 locations, and rainfall recorded at 187 stations. These sites continuously record data on 15-minute intervals and transmit the data via satellite to be incorporated into the USGS National Water Information System database. These data are automatically posted to the USGS Web site for public dissemination (http://waterdata.usgs.gov/ga/nwis/nwis). The real-time capability of this network provides information to help emergency-management officials protect human life and property during floods, and mitigate the effects of prolonged drought. The map at right shows the USGS streamflow monitoring network for Georgia and major watersheds. Streamflow is monitored at 198 sites statewide, more than 80 percent of which include precipitation gages. Various Federal, State, and local agencies fund these streamflow monitoring stations.

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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

  14. Methods for estimating drought streamflow probabilities for Virginia streams

    USGS Publications Warehouse

    Austin, Samuel H.

    2014-01-01

    Maximum likelihood logistic regression model equations used to estimate drought flow probabilities for Virginia streams are presented for 259 hydrologic basins in Virginia. Winter streamflows were used to estimate the likelihood of streamflows during the subsequent drought-prone summer months. The maximum likelihood logistic regression models identify probable streamflows from 5 to 8 months in advance. More than 5 million streamflow daily values collected over the period of record (January 1, 1900 through May 16, 2012) were compiled and analyzed over a minimum 10-year (maximum 112-year) period of record. The analysis yielded the 46,704 equations with statistically significant fit statistics and parameter ranges published in two tables in this report. These model equations produce summer month (July, August, and September) drought flow threshold probabilities as a function of streamflows during the previous winter months (November, December, January, and February). Example calculations are provided, demonstrating how to use the equations to estimate probable streamflows as much as 8 months in advance.

  15. 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.

  16. 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.

  17. Estimation of peak streamflows for unregulated rural streams in Kansas

    USGS Publications Warehouse

    Rasmussen, Patrick P.; Perry, Charles A.

    2000-01-01

    Peak streamflows were estimated at selected recurrence intervals (frequencies) ranging from 2 to 200 years using log-Pearson Type III distributions for 253 streamflow-gaging stations in Kansas. The annual peak-streamflow data, through the 1997 water year, were from streamflow-gaging stations with unregulated flow in mostly rural basins. A weighted least-squares regression model was used to generalize the coefficients of station skewness. The resulting generalized skewness equation provides more reliable estimates than the previously developed equation for Kansas. A generalized least-squares regression model then was used to develop equations for estimating peak streamflows for sites without stream gages for selected frequencies from selected physical and climatic basin characteristics for sites without stream gages. The equations can be used to estimate peak streamflows for selected frequencies using contributing-drainage area, mean annual precipitation, soil permeability, and slope of the main channel for ungaged sites in Kansas with a contributing-drainage area greater than 0.17 and less than 9,100 square miles. The errors of prediction for the generalized least-squares-generated equations range from 31 to 62 percent.

  18. 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.

  19. 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.

  20. 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...

  1. 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

  2. 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.

    2016-04-05

    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.

  3. Seasonal Streamflow Forecasts for African Basins

    NASA Astrophysics Data System (ADS)

    Serrat-Capdevila, A.; Valdes, J. B.; Wi, S.; Roy, T.; Roberts, J. B.; Robertson, F. R.; Demaria, E. M.

    2015-12-01

    Using high resolution downscaled seasonal meteorological forecasts we present the development and evaluation of seasonal hydrologic forecasts with Stakeholder Agencies for selected African basins. The meteorological forecasts are produced using the Bias Correction and Spatial Disaggregation (BCSD) methodology applied to NMME hindcasts (North American Multi-Model Ensemble prediction system) to generate a bootstrap resampling of plausible weather forecasts from historical observational data. This set of downscaled forecasts is then used to drive hydrologic models to produce a range of forecasts with uncertainty estimates suitable for water resources planning in African pilot basins (i.e. Upper Zambezi, Mara Basin). In an effort to characterize the utility of these forecasts, we will present an evaluation of these forecast ensembles over the pilot basins, and discuss insights as to their operational applicability by regional actors. Further, these forecasts will be contrasted with those from a standard Ensemble Streamflow Prediction (ESP) approach to seasonal forecasting. The case studies presented here have been developed in the setting of the NASA SERVIR Applied Sciences Team and within the broader context of operational seasonal forecasting in Africa. These efforts are part of a dialogue with relevant planning and management agencies and institutions in Africa, which are in turn exploring how to best use uncertain forecasts for decision making.

  4. 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.

  5. 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

  6. Soil moisture response to experimentally altered snowmelt timing is mediated by soil, vegetation, and regional climate patterns

    USGS Publications Warehouse

    Conner, Lafe G; Gill, Richard A.; Belnap, Jayne

    2016-01-01

    Soil moisture in seasonally snow-covered environments fluctuates seasonally between wet and dry states. Climate warming is advancing the onset of spring snowmelt and may lengthen the summer-dry state and ultimately cause drier soil conditions. The magnitude of either response may vary across elevation and vegetation types. We situated our study at the lower boundary of persistent snow cover and the upper boundary of subalpine forest with paired treatment blocks in aspen forest and open meadow. In treatments plots, we advanced snowmelt timing by an average of 14 days by adding dust to the snow surface during spring melt. We specifically wanted to know whether early snowmelt would increase the duration of the summer-dry period and cause soils to be drier in the early-snowmelt treatments compared with control plots. We found no difference in the onset of the summer-dry state and no significant differences in soil moisture between treatments. To better understand the reasons soil moisture did not respond to early snowmelt as expected, we examined the mediating influences of soil organic matter, texture, temperature, and the presence or absence of forest. In our study, late-spring precipitation may have moderated the effects of early snowmelt on soil moisture. We conclude that landscape characteristics, including soil, vegetation, and regional weather patterns, may supersede the effects of snowmelt timing in determining growing season soil moisture, and efforts to anticipate the impacts of climate change on seasonally snow-covered ecosystems should take into account these mediating factors. 

  7. 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.

  8. 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

  9. A statistical analysis of the daily streamflow hydrograph

    NASA Astrophysics Data System (ADS)

    Kavvas, M. L.; Delleur, J. W.

    1984-03-01

    In this study a periodic statistical analysis of daily streamflow data in Indiana, U.S.A., was performed to gain some new insight into the stochastic structure which describes the daily streamflow process. This analysis was performed by the periodic mean and covariance functions of the daily streamflows, by the time and peak discharge -dependent recession limb of the daily streamflow hydrograph, by the time and discharge exceedance level (DEL) -dependent probability distribution of the hydrograph peak interarrival time, and by the time-dependent probability distribution of the time to peak discharge. Some new statistical estimators were developed and used in this study. In general features, this study has shown that: (a) the persistence properties of daily flows depend on the storage state of the basin at the specified time origin of the flow process; (b) the daily streamflow process is time irreversible; (c) the probability distribution of the daily hydrograph peak interarrival time depends both on the occurrence time of the peak from which the inter-arrival time originates and on the discharge exceedance level; and (d) if the daily streamflow process is modeled as the release from a linear watershed storage, this release should depend on the state of the storage and on the time of the release as the persistence properties and the recession limb decay rates were observed to change with the state of the watershed storage and time. Therefore, a time-varying reservoir system needs to be considered if the daily streamflow process is to be modeled as the release from a linear watershed storage.

  10. 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.

  11. 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

  12. 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

  13. Snowmelt Infiltration Into Alpine Soils Visualised In Situ With A Dye Tracer Method

    NASA Astrophysics Data System (ADS)

    Stähli, M.; Bayard, D.; Wydler, H.; Flühler, H.

    The mechanisms governing snowmelt infiltration into frozen or unfrozen alpine soils are complex due to the fact that many factors influence the flow paths from the snow pack into the soil, such as soil type, slope inclination and aspect, ground vegetation and the occurrence and persistence of ice on the soil surface or in the frozen soil. Dye tracer experiments are a feasible method to provide a better insight into the real distribution of such water flow paths, which can be very preferential. The main objec- tive of this study was to test the potential of dye tracer methods for visualising in situ snowmelt infiltration at alpine sites and to gain quantitative information on snowmelt infiltration into frozen and unfrozen soils. Field experiments were carried out during winter 2000/01 in southern Switzerland at Hannigalp (2100 m a.s.l.), where a 60 to 80 cm deep Ferric Podzole facing north-west is covered by sparse Ericaceae, and at Gd-St-Bernard pass (2500 m a.s.l.), where a shallow stony Ranker facing south is cov- ered with grass. At the beginning of December a dye tracer (Brilliant Blue FCF) was applied on the soil surface covering an area 5 m downhill x 1.5 m horizontally. At dif- ferent stages during the snowmelt (March to June) we excavated vertical soil profiles on these plots (from below upwards) and took photographs of the stained soil profiles using a digital camera. From these digital images the areas of the soil profiles stained with the dye tracer were determined using a supervised classification method, and the depth distribution of areal coverage of dye tracer was calculated. The water flow pat- tern showed to be extremely heterogeneous in the Hannigalp soil, and more uniform in the Gd-St-Bernard soil. Already in an early stage of the snowmelt we observed infil- tration down to 40 to 60 cm, indicating a relatively high soil matrix infiltration rate at Gd-St-Bernard and efficient preferential flow channels (e.g. along roots) at Hannigalp. Soil frost

  14. 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

  15. Environmentally benign hardness removal using ion-exchange fibers and snowmelt.

    PubMed

    Greenleaf, John E; Sengupta, Arup K

    2006-01-01

    Many industrial unit operations and unit processes require near-complete removal of hardness to avoid scaling in heat-transfer equipment, fouling in membranes, and high consumption of detergents and sequestering chemicals in cooling and wash water. Lime softening and cation exchange are the most commonly used processes practiced to date for hardness removal. Herein, we report and discuss the results and attributes of a new hardness removal process using ion-exchange fibers (IX-fibers). Most importantly, the process uses harvested snowmelt (or rainwater) as the regenerant chemical along with sparged carbon dioxide. Consequently, the spent regenerant does not contain a high concentration of aggressive chemicals such as sodium chloride or acid like traditional ion-exchange processes nor does the process produce voluminous sludges similar to lime softening. The bulk of carbon dioxide consumed during regeneration remains sequestered in the aqueous phase as alkalinity. IX-fibers form the heart of the process. They are essentially thin cylindrical polymeric strands 10-20 microm in diameter. The weak-acid carboxylate functional groups reside near to the surface of these cylindrical fibers. Low intraparticle diffusional resistance is the underlying reason IX-fibers are amenable to efficient regeneration with snowmelt sparged with carbon dioxide. When the carbon dioxide partial pressure is increased to 6.8 atm, over 90% calcium desorption efficiency is obtained. On the contrary, commercial weak-acid ion-exchange resins in spherical bead forms are ineffective for regeneration with carbon-dioxide-sparged snowmelt due to extremely slow ion-exchange kinetics involving counter-transport of Ca2+ and H+.

  16. 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.

  17. Particles and associated metals in road runoff during snowmelt and rainfall.

    PubMed

    Westerlund, Camilla; Viklander, Maria

    2006-06-01

    This study analysed road runoff in northern Sweden with respect to the concentrations of and the loads of particles in different size fractions (4-6, 6-9, 9-15, 15-25, 25-40, and 40-120 mum) between a snowmelt period and a rainfall period, as well as during events within each period. There are also comparisons of the transport of different particle sizes between the two periods and during events within the periods and discussions on how different metals are associated with the varying particle sizes. The results showed, on average, eight times higher concentrations and five times higher loads of particles during the snowmelt period compared to the rain period for all particle size intervals. Using a t-test with 14 degrees of freedom, at a 90% and 95% confidence level, the mean- and the event mean concentrations of all particle size intervals were higher during the melt period compared to the rain period. Also, the particle concentrations for both periods decrease as the particle size increases. During the snowmelt and rainfall period, important factors influencing the concentrations and loads were the availability of material, the intensity of the lateral flow for the transport of the particles, and, additionally, for the rain period, the length of dry weather in between events. During the melt period, investigated particle sizes and TSS were highly correlated with total concentrations of Cd, Cu, Ni, Pb, and Zn. During the rain period, the correlations between total metal concentrations and the different particle sizes were not as significant.

  18. 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

  19. 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

  20. 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

  1. Semi-distributed snowmelt modeling and regional snow mapping using passive microwave radiometry

    NASA Astrophysics Data System (ADS)

    Singh, Purushottam Raj

    2002-01-01

    Two semi-distributed snowmelt models (SDSM-MTI and SDSM-EBM) developed to model the basin-scale snow accumulation and ablation processes at sub-basin scale, were applied to the Paddle River Basin (PRB) of central Alberta. SDSM-MTI uses a modified temperature index approach that consists of a weighted average of near surface soil (Tg) and air temperature (Ta) data. SDSM-EBM, a relatively data intensive energy balance model accounts for snowmelt by considering (a) vertical energy exchange in open and forested area separately; (b) snowmelt in terms of liquid and ice phases separately, canopy interception, snow density, sublimation, refreezing, etc, and (c) the snow surface temperature. Other than the "regulatory" effects of beaver dams, both models simulated reasonably accurate snowmelt runoff, SWE and snow depth for PRB. For SDSM-MTI, the advantage of using both Ta and Tg is partly attributed to T g showing a stronger correlation with solar and net radiation at PRB than Ta. Existing algorithms for retrieving snow water equivalent (SWE) from the Special Sensor Microwave/Imager (SSM/I) passive microwave brightness temperature data were assessed and new algorithms were developed for the Red River basin of North Dakota and Minnesota. The frequencies of SSM/I data used are 19 and 37 GHz in both horizontal and vertical polarization. The airborne gamma-ray measurements of SWE for 1989, 1988, and 1997 provided the ground truth for algorithm development and validation. Encouraging calibration results are obtained for the multivariate regression algorithms and dry snow cases of the 1989 and 1988 SSM/I data (from DMSP-F8). Similarly, validation results e.g., 1988 (1989 as calibration data), 1989 (1988 as calibration data), and 1997 (from DMSP-F10 and F13), are also encouraging. The non-parameric, Projection Pursuit Regression technique also gave good results in both stages. However, for the validation stage, adding a shift parameter to all retrieval algorithms was necessary

  2. 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.

  3. Modelling the spatial-temporal variability of spring snowmelt in an arctic catchment

    NASA Astrophysics Data System (ADS)

    Pohl, S.; Marsh, P.

    2006-05-01

    Arctic spring landscapes are usually characterized by a mosaic of coexisting snow-covered and bare ground patches. This phenomenon has major implications for hydrological processes, including meltwater production and runoff. Furthermore, as indicated by aircraft observations, it affects land-surface-atmosphere exchanges, leading to a high degree of variability in surface energy terms during melt. The heterogeneity and related differences when certain parts of the landscape become snow free also affects the length of the growing season and the carbon cycle.Small-scale variability in arctic snowmelt is addressed here by combining a spatially distributed end-of-winter snow cover with simulations of variable snowmelt energy balance factors for the small arctic catchment of Trail Valley Creek (63 km2). Throughout the winter, snow in arctic tundra basins is redistributed by frequent blowing snow events. Areas of above- or below-average end-of-winter snow water equivalents were determined from land-cover classifications, topography, land-cover-based snow surveys, and distributed surface wind-field simulations. Topographic influences on major snowmelt energy balance factors (solar radiation and turbulent fluxes of sensible and latent heat) were modelled on a small-scale (40 m) basis. A spatially variable complete snowmelt energy balance was subsequently computed and applied to the distributed snow cover, allowing the simulation of the progress of melt throughout the basin. The emerging patterns compared very well visually to snow cover observations from satellite images and aerial photographs.Results show the relative importance of variable end-of-winter snow cover, spatially distributed melt energy fluxes, and local advection processes for the development of a patchy snow cover. This illustrates that the consideration of these processes is crucial for an accurate determination of snow-covered areas, as well as the location, timing, and amount of meltwater release from

  4. 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

  5. Snowmelt and water resources in a changing climate and dustier world

    NASA Astrophysics Data System (ADS)

    Painter, T. H.

    2015-12-01

    Snow cover and its melt dominate regional climate and water resources in the world's mountain regions, providing for critical agricultural and sustaining populations in otherwise dry regions. Snowmelt timing and magnitude in mountains tend to be controlled by absorption of solar radiation and snow water equivalent, respectively, and yet both of these are very poorly known even in the best-instrumented mountain regions of the globe. In this talk, we discuss developments in the spaceborne and airborne remote sensing of snow properties, and the assimilation of these products into research water cycle modeling and operational forecasting. Our work with the NWS Colorado Basin River Forecast Center has shown marked improvements in runoff forecasting through inclusion of MODIS and VIIRS fractional snow covered area data. Moreover, the analyses have shown that the CBRFC forecasting errors are strongly sensitive to actual dust radiative forcing in snow with rising limb excursions as large as 40%. With MODIS retrievals of dust radiative forcing, the CBRFC will be implementing modifications to forecasts to reduce those errors to order < 10%. In the last few years, the NASA Airborne Snow Observatory has emerged to provide the first spatially explicit distributions of snow water equivalent and coincident snow albedo products for mountain basins. ASO is an imaging spectrometer and imaging LiDAR system, to quantify snow water equivalent and snow albedo, provide unprecedented knowledge of snow properties, and provide complete, robust inputs to snowmelt runoff models, water management models, and systems of the future. ASO has been flying in the Western US for three snowmelt seasons. In 2015, ASO provided complete basin coverage for the Tuolumne, Merced, Lakes, Rush Creek, and Middle+South Forks of Kings River Basins in the California Sierra Nevada and the Upper Rio Grande, Conejos, and Uncompahgre Basins in the Colorado Rocky Mountains. Analyses show that with ASO data, river

  6. 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

  7. 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

  8. Shrubs, streamflow, and the paradox of scale

    NASA Astrophysics Data System (ADS)

    Wilcox, Bradford P.; Owens, M. Keith; Dugas, William A.; Ueckert, Darrell N.; Hart, Charles R.

    2006-10-01

    In this paper, we examine the linkage between woody plants and the water budget for three important woody plant communities in Texas, USA: saltcedar (Tamarix chinensis, Tamarix ramosissima), Ashe juniper (Juniperus ashei Buchholz), and mesquite (Prosopis glandulosa Torr. var. glandulosa). In most cases, these species are found in distinct physiographic and soil settings. Saltcedar is restricted to stream channels and floodplains; Ashe juniper is found mostly on karst limestone outcrops with shallow soils; and mesquite is found on deep soils. Because of these differences, changes in woody plant cover in each community will have a different effect on the water budget. For each type, we review the available literature and explicitly report the scale of observation (tree, stand, catchment, or landscape). A simple framework called the shrub-streamflow framework, which recognizes differences in response due to differences in physiographic setting, climate, and potential for deep drainage or subsurface flow, enables us to generalize the results. The fundamental premise of the framework is simple: for shrublands to be hydrologically sensitive to changes in woody plant cover, soil water or groundwater must be accessible to deep-rooting plants but too deep for shallow-rooting ones. Such a situation exists if groundwater is close to the surface (within 3-5 m and/or if deep drainage occurs (because of either high precipitation input or bypass flow in the soil). We argue that on an area basis, conversion of saltcedar stands to herbaceous plants in riparian regions has a much greater potential for increasing water yield than does conversion of woodlands to grasslands in upland regions where deep drainage does not occur. On upland sites where deep drainage does occur, conversion from woody to herbaceous vegetation may result in a savings of 40-80 mm year-1 of water. But such savings have been observed only up to the small-catchment scale, and until further work is done it is

  9. 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

  10. Historical Changes in Precipitation and Streamflow in the U.S. Great Lakes Basin, 1915-2004

    USGS Publications Warehouse

    Hodgkins, Glenn A.; Dudley, Robert W.; Aichele, Stephen S.

    2007-01-01

    for February, March, and April, which were likely due to lower ratios of snowfall to rain and earlier snowmelt runoff in recent years. Increases in precipitation were larger than increases in runoff for May, June, August, September, and October. Some of this difference could be due to the different locations of the precipitation and streamflow stations in the basin. Part of the difference may be explained by changes in evapotranspiration. Some of the few highly urbanized and highly regulated stations analyzed in this report had larger increases in annual 7-day low-runoff from 1955 to 2004 than any of the stations in the U.S. Great Lakes Basin that are on streams relatively free of human influences. This demonstrates the human influence over time on very low streamflows. Changes-even over periods as long as 90 years-can be part of longer cycles. Previous studies of Great Lakes Basin precipitation and St. Lawrence River streamflow, using data from the mid-1800s to the late-1900s, showed low precipitation and streamflow in the late 1800s and early 1900s relative to earlier and later periods.

  11. Statistical summaries of selected Iowa streamflow data through September 2013

    USGS Publications Warehouse

    Eash, David A.; O'Shea, Padraic S.; Weber, Jared R.; Nguyen, Kevin T.; Montgomery, Nicholas L.; Simonson, Adrian J.

    2016-01-04

    Statistical summaries of streamflow data collected at 184 streamgages in Iowa are presented in this report. All streamgages included for analysis have at least 10 years of continuous record collected before or through September 2013. This report is an update to two previously published reports that presented statistical summaries of selected Iowa streamflow data through September 1988 and September 1996. The statistical summaries include (1) monthly and annual flow durations, (2) annual exceedance probabilities of instantaneous peak discharges (flood frequencies), (3) annual exceedance probabilities of high discharges, and (4) annual nonexceedance probabilities of low discharges and seasonal low discharges. Also presented for each streamgage are graphs of the annual mean discharges, mean annual mean discharges, 50-percent annual flow-duration discharges (median flows), harmonic mean flows, mean daily mean discharges, and flow-duration curves. Two sets of statistical summaries are presented for each streamgage, which include (1) long-term statistics for the entire period of streamflow record and (2) recent-term statistics for or during the 30-year period of record from 1984 to 2013. The recent-term statistics are only calculated for streamgages with streamflow records pre-dating the 1984 water year and with at least 10 years of record during 1984–2013. The streamflow statistics in this report are not adjusted for the effects of water use; although some of this water is used consumptively, most of it is returned to the streams.

  12. Validation of streamflow measurements made with acoustic doppler current profilers

    USGS Publications Warehouse

    Oberg, K.; Mueller, D.S.

    2007-01-01

    The U.S. Geological Survey and other international agencies have collaborated to conduct laboratory and field validations of acoustic Doppler current profiler (ADCP) measurements of streamflow. Laboratory validations made in a large towing basin show that the mean differences between tow cart velocity and ADCP bottom-track and water-track velocities were -0.51 and -1.10%, respectively. Field validations of commercially available ADCPs were conducted by comparing streamflow measurements made with ADCPs to reference streamflow measurements obtained from concurrent mechanical current-meter measurements, stable rating curves, salt-dilution measurements, or acoustic velocity meters. Data from 1,032 transects, comprising 100 discharge measurements, were analyzed from 22 sites in the United States, Canada, Sweden, and The Netherlands. Results of these analyses show that broadband ADCP streamflow measurements are unbiased when compared to the reference discharges regardless of the water mode used for making the measurement. Measurement duration is more important than the number of transects for reducing the uncertainty of the ADCP streamflow measurement. ?? 2007 ASCE.

  13. Streamflow gain and loss of selected streams in northern Arkansas

    USGS Publications Warehouse

    Freiwald, David A.

    1987-01-01

    This map shows streamflow gain and loss measurements (seepage runs) on the Crooked, Osage, and Spavinaw Creeks, and Illinois, Kings, Mulberry, Spring, and Strawberry Rivers during the low-flow conditions from September 1982 to October 1984. Data indicated that streamflow gains and losses resulted from differences in lithology of the predominately carbonate rocks and from the presence of faults. The Kings and Strawberry Rivers and Osage Creek were gaining streams throughout their length, however wastewater discharges precluded an accurate determination on Osage Creek. Crooked and Spavinaw Creeks and the Illinois, Spring, and Mulberry Rivers generally were gaining streams throughout most of their lengths although short losing reaches were identified. The largest gains in streamflow generally occurred were Mississippian formation predominated near the streams. Faults that intersected the stream channels primarily were responsible for streamflow losses. The specific conductance of water increased in the stream reaches that had the most significant streamflow gains. The specific conductance of water in tributaries was generally higher than that in larger streams. (Author 's abstract)

  14. 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.

  15. Analytical characterization of the spatial correlation of streamflows

    NASA Astrophysics Data System (ADS)

    Betterle, Andrea; Schirmer, Mario; Botter, Gianluca

    2016-04-01

    In this study, we establish an analytical approach to estimate the spatial correlation of daily streamflows in two arbitrary locations within a given hydrologic district or river basin at seasonal and annual time scales. The method is based on a stochastic description of the coupled streamflow dynamics at the outlet of two catchments. The framework aims to express the correlation of daily streamflows at two locations along a river network as a function of a limited number of parameters characterizing the main underlying hydrological drivers, that include climate conditions, precipitation regime and catchment drainage rates. The proposed method portrays how heterogeneity of climate and landscape features affect the spatial variability of flow regimes along river systems. In particular, we show that frequency and intensity of synchronous effective rainfall events in the relevant contributing catchments are the main driver of the spatial correlation of daily discharge, whereas only pronounced differences in the drainage rate of the two basins bear a significant effect on the streamflow correlation. The topological arrangement of the two outlets also influences the underlying streamflow correlation, as we show that nested catchments tend to maximize the spatial correlation of flow regimes. The application of the method to a set of catchments in the South-Eastern US suggests the potential of the proposed tool for the characterization of spatial connections of flow regimes in the absence of discharge measurements.

  16. A stochastic model of streamflow for urbanized basins

    NASA Astrophysics Data System (ADS)

    Mejía, Alfonso; Daly, Edoardo; Rossel, Florian; Jovanovic, Tijana; Gironás, Jorge

    2014-03-01

    Given the critical role of the streamflow regime for instream, riparian, and floodplain ecosystem sustainability, modeling the long-term effect of urbanization on streamflow is important to predict possible changes in stream ecosystems. Since flow duration curves are largely used to characterize the streamflow regime and define indices for stream ecosystem health, we present two stochastic models, with different levels of complexity, that link the key physical features of urbanized basins with rainfall variability to determine the resulting flow duration curves. The two models are tested against 11 basins with various degrees of urban development, characterized by the percentage of impervious areas in the basin. Results show that the more complex model needs to be used to reproduce accurately the entire flow duration curve. The analysis performed suggests that the transformation of green (i.e., water used in evapotranspiration) to blue (i.e., streamflow) water in urbanized basins is an important long-term source of ecohydrological alteration. The modeling scheme also provides useful links between rainfall variability, urbanization levels, and some streamflow indices of high and low flows.

  17. Assessing the ability of operational snow models to predict snowmelt runoff extremes (Invited)

    NASA Astrophysics Data System (ADS)

    Wood, A. W.; Restrepo, P. J.; Clark, M. P.

    2013-12-01

    In the western US, the snow accumulation and melt cycle of winter and spring plays a critical role in the region's water management strategies. Consequently, the ability to predict snowmelt runoff at time scales from days to seasons is a key input for decisions in reservoir management, whether for avoiding flood hazards or supporting environmental flows through the scheduling of releases in spring, or for allocating releases for multi-state water distribution in dry seasons of year (using reservoir systems to provide an invaluable buffer for many sectors against drought). Runoff forecasts thus have important benefits at both wet and dry extremes of the climatological spectrum. The importance of the prediction of the snow cycle motivates an assessment of the strengths and weaknesses of the US's central operational snow model, SNOW17, in contrast to process-modeling alternatives, as they relate to simulating observed snowmelt variability and extremes. To this end, we use a flexible modeling approach that enables an investigation of different choices in model structure, including model physics, parameterization and degree of spatiotemporal discretization. We draw from examples of recent extreme events in western US watersheds and an overall assessment of retrospective model performance to identify fruitful avenues for advancing the modeling basis for the operational prediction of snow-related runoff extremes.

  18. 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.

  19. Forest floor frost dynamics during spring snowmelt in a boreal forested basin

    NASA Astrophysics Data System (ADS)

    Stein, Jean; Proulx, Serge; LéVesque, Denis

    1994-04-01

    A previous study (Prévost et al., 1990) has shown that a lowering in the soil infiltrability index improves hydrograph snowmelt runoff peaks simulation of the Lac Laflamme basin. The hypothesis that explains this phenomenon is as follows: when the snowpack becomes discontinuous or thin during the spring, cold air temperatures during the night (<-10°C) freeze the water at the soil surface. To test this hypothesis, four plots were instrumented to follow the evolution of water table fluctuations, snow cover area, soil and air temperatures, and liquid and total water contents at different levels in the soil. Transect lines were also established to monitor snow depth, percentage of soil free of snow, and presence of basal ice and different types of soil frost (porous or concrete). Our results show that the minimum nightly air temperature of -5°C during snowmelt did not produce soil ice. It was not possible to validate or invalidate the hypothesis. The results of the survey at the basin scale show that concrete frost is prevalent throughout the basin, is associated with forest floors dominated by sphagnum or hypnobryale mosses, and originates from winter meteorological events.

  20. 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.

  1. A proposed streamflow-data program for North Dakota

    USGS Publications Warehouse

    Crosby, O.A.

    1970-01-01

    An evaluation of the streamflow data available in North Dakota 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. None of the goals could be met by generalization of the data for gaged basins by regression analysis. This fact indicates that significant changes should be made in the present data program to obtain better areal coverage to achieve the goals set. A streamflow data program based on the guidelines developed in this study is proposed for the future.

  2. Peak streamflow on selected streams in Arkansas, December 2015

    USGS Publications Warehouse

    Breaker, Brian K.

    2017-01-11

    Heavy rainfall during December 2015 resulted in flooding across parts of Arkansas; rainfall amounts were as high as 12 inches over a period from December 27, 2015, to December 29, 2015. Although precipitation accumulations were highest in northwestern Arkansas, significant flooding occurred in other parts of the State. Flood damage occurred in several counties as water levels rose in streams, and disaster declarations were declared in 32 of the 75 counties in Arkansas.Given the severity of the December 2015 flooding, the U.S. Geological Survey (USGS), in cooperation with the Federal Emergency Management Agency (FEMA), conducted a study to document the meteorological and hydrological conditions prior to and during the flood; compiled flood-peak gage heights, streamflows, and flood probabilities at USGS streamflow-gaging stations; and estimated streamflows and flood probabilities at selected ungaged locations.

  3. Streamflow-Characteristic Estimation Methods for Unregulated Streams of Tennessee

    USGS Publications Warehouse

    Law, George S.; Tasker, Gary D.; Ladd, David E.

    2009-01-01

    Streamflow-characteristic estimation methods for unregulated rivers and streams of Tennessee were developed by the U.S. Geological Survey in cooperation with the Tennessee Department of Environment and Conservation. Streamflow estimates are provided for 1,224 stream sites. Streamflow characteristics include the 7-consecutive-day, 10-year recurrence-interval low flow, the 30-consecutive-day, 5-year recurrence-interval low flow, the mean annual and mean summer flows, and the 99.5-, 99-, 98-, 95-, 90-, 80-, 70-, 60-, 50-, 40-, 30-, 20-, and 10-percent flow durations. Estimation methods include regional regression (RRE) equations and the region-of-influence (ROI) method. Both methods use zero-flow probability screening to estimate zero-flow quantiles. A low flow and flow duration (LFFD) computer program (TDECv301) performs zero-flow screening and calculation of nonzero-streamflow characteristics using the RRE equations and ROI method and provides quality measures including the 90-percent prediction interval and equivalent years of record. The U.S. Geological Survey StreamStats geographic information system automates the calculation of basin characteristics and streamflow characteristics. In addition, basin characteristics can be manually input to the stand-alone version of the computer program (TDECv301) to calculate streamflow characteristics in Tennessee. The RRE equations were computed using multivariable regression analysis. The two regions used for this study, the western part of the State (West) and the central and eastern part of the State (Central+East), are separated by the Tennessee River as it flows south to north from Hardin County to Stewart County. The West region uses data from 124 of the 1,224 streamflow sites, and the Central+East region uses data from 893 of the 1,224 streamflow sites. The study area also includes parts of the adjacent States of Georgia, North Carolina, Virginia, Alabama, Kentucky, and Mississippi. Total drainage area, a geology

  4. 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.

  5. 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.

  6. 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

  7. Arctic Ocean Snowmelt Onset Dates Derived from Passive Microwave for 1979- 2005.

    NASA Astrophysics Data System (ADS)

    Anderson, M. R.; Molthan, A. L.; Jackson, B. A.

    2006-12-01

    The Arctic Ocean is an integral part of the global climate system and an area that is observing record breaking seasonal fluctuations. This study investigates the spring snowmelt onset conditions in the Arctic sea ice cover from 1979 to 2005. Snowmelt onset over Arctic sea ice is defined as the point in time when liquid water appears in the snowpack. Physically, the timing of snowmelt onset is important because surface energy absorption increases rapidly at snowmelt onset, owing to changes in surface albedo values. Monitoring the timing of snowmelt onset over Arctic sea ice is facilitated by using passive microwave data, because surface microwave emission changes rapidly when liquid water appears in the snowpack, and data acquisitions are relatively unaffected by cloud cover or solar illumination. The Advanced Horizontal Range Algorithm (AHRA) exploits the changes in passive microwave brightness temperatures between 18GHz (19GHz on SSM/I) and 37GHz brightness temperatures to derive snow melt onset dates over Arctic sea ice from 1979-2005. Comparison between AHRA-derived melt onset dates and temperatures from International Arctic Buoy Program/Polar Exchange at the Sea Surface (IABP/POLES) and NCEP/NCAR Reanalysis-2 illustrates melt onset typically occurs when air temperatures near 0oC. The objective of this paper is to examine the melt onset dates for the Arctic region and discuss the trends in the dates over the period studied. In addition, ice reduction dates are calculated and compared to the melt onset dates to further understand the melt characteristics during the spring. The ice reduction date is when the ice concentration drops below 80%. Both the melt onset and ice reduction dates are derived from passive microwave remote sensing. There is a notable period of time, delta t, between the melt onset and ice reduction. Analysis of delta t for the Arctic over the microwave record provides explanations for changes in sea ice cover over time. For instance, an

  8. LARGE-SCALE PATTERNS OF STREAMFLOW DISTURBANCE AND FISH ASSEMBLAGES 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. Ecological organization of stream communities has been linked to streamflow, especially to patterns of flow variability that describe the physical disturbanc...

  9. 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...

  10. 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

  11. 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

  12. 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

  13. Evaluating Effects of Climate Change and Variability on Snowmelt Runoff Timing and Magnitude in Northern New Mexico

    NASA Astrophysics Data System (ADS)

    Hafich, K. A.; Sherson, L. R.; Crossey, L. J.; Dahm, C.

    2010-12-01

    In the mountains of northern New Mexico, potential impacts of climate change include alteration in the amount and timing of runoff of surface water. More than half of the available surface water in New Mexico comes from high elevation watersheds, making it critical to understand discharge trends in order to provide water to sustain the population and economy of New Mexico. Climate change affects temperature and the rate, timing, and form of precipitation that in turn could result in a change in snowmelt timing and flow quantities over the annual hydrograph. Updated and enhanced methods to predict the timing and yield of water from stream basins and the amount of water that can be used for agriculture and municipal use are needed. Here, we examine the use of stream discharge to model temporal and spatial trends of available water. Historical discharge records for two mountain streams in northern New Mexico, the Jemez River and Rio Hondo, were examined for trends in the timing of the start and the end of snowmelt runoff. We also examine trends in the snowmelt season fractional flows (ratio of selected monthly intervals during snowmelt season to total annual flow). Snowmelt start and end days were determined as the day on which the cumulative flow departure from average was at a minimum and maximum, resulting in a hydrograph (rather than discharge) driven metric. Changes in timing and trends were analyzed using statistical methods including correlation testing and regression analysis. Models of snowmelt amount and timing can be used as baseline comparisons through which improved infrastructure for monitoring and modeling climate change impacts on New Mexico’s mountain sources of water can be developed. Detailed sampling of the Jemez and Hondo watersheds through annual hydrological cycles will provide isotopic and hydrochemical data that can assist in hydrograph separation between snowmelt and base flows sustained by deeper groundwater flows. In 2010, a network of

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. 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

  20. 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

  1. Impact of global warming on streamflow drought in Europe

    NASA Astrophysics Data System (ADS)

    Feyen, Luc; Dankers, Rutger

    2009-09-01

    Recent developments in climate modeling suggest that global warming is likely to favor conditions for the development of droughts in many regions of Europe. Studies evaluating possible changes in drought hazard typically have employed indices that are derived solely from climate variables such as temperature and precipitation, whereas many of the impacts of droughts are more related to hydrological variables such as river flow. This study examines the impact of global warming on streamflow drought in Europe by comparing low-flow predictions of a hydrological model driven by high-resolution regional climate simulations for the end of the previous century and for the end of this century based on the Special Report on Emissions Scenarios A2 greenhouse gas emission scenario. For both time slices, low-flow characteristics were derived from the simulated streamflow series using extreme value analysis. More specifically, we employed the methods of block maxima and partial duration series to obtain minimum flows and flow deficits and fitted extreme value distributions by the maximum likelihood method. In order not to mix drought events with different physical causes the analysis was performed separately for the frost and nonfrost season. Results show that in the frost-free season streamflow droughts will become more severe and persistent in most parts of Europe by the end of this century, except in the most northern and northeastern regions. In the frost season, streamflow drought conditions will be of less importance under future climate conditions.

  2. Watershed Modeling to Assess the Sensitivity of Streamflow ...

    EPA Pesticide Factsheets

    EPA has released for independent external peer review and public comment a draft report titled, Watershed Modeling to Assess the Sensitivity of Streamflow, Nutrient, and Sediment Loads to Potential Climate Change and Urban Development in 20 U.S. Watersheds. This is a draft document that intends to characterize the sensitivity of streamflow, nutrient (nitrogen and phosphorus), and sediment loading in different regions of the nation to a range of plausible mid-21st Century climate change and urban development scenarios. Watershed modeling was conducted in 20 large, U.S. watersheds to assess the sensitivity of streamflow, nutrient (nitrogen and phosphorus), and sediment loading to a range of plausible mid-21st Century climate change and urban development scenarios in different regions of the nation. This draft report provides a summary of simulation results. The model simulations characterize the sensitivity of streamflow, nutrient (nitrogen and phosphorus), and sediment loading to a range of plausible mid-21st Century climate change and urban development. Results show a high degree of variability in the response throughout the nation. Results also provide an improved understanding of methodological challenges associated with integrating existing tools and datasets to address these scientific questions. This provides guidance for improving how existing models and datasets can be used for assessing climate change impacts on watersheds. Projected changes in cli

  3. 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.

  4. 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

  5. Regional changes in streamflow after a megathrust earthquake

    NASA Astrophysics Data System (ADS)

    Mohr, Christian H.; Manga, Michael; Wang, Chi-Yuen; Korup, Oliver

    2017-01-01

    Moderate to large earthquakes can increase the amount of water feeding stream flows, mobilizing excess water from deep groundwater, shallow groundwater, or the vadose zone. Here we examine the regional pattern of streamflow response to the Maule M8.8 earthquake across Chile's diverse topographic and hydro-climatic gradients. We combine streamflow analyses with groundwater flow modeling and a random forest classifier, and find that, after the earthquake, at least 85 streams had a change in flow. Discharge mostly increased (n = 78) shortly after the earthquake, liberating an excess water volume of >1.1 km3, which is the largest ever reported following an earthquake. Several catchments had increased discharge of >50 mm, locally exceeding seasonal streamflow discharge under undisturbed conditions. Our modeling results favor enhanced vertical permeability induced by dynamic strain as the most probable process explaining the observed changes at the regional scale. Supporting this interpretation, our random forest classification identifies peak ground velocity and elevation extremes as most important for predicting streamflow response. Given the mean recurrence interval of ∼25 yr for >M8.0 earthquakes along the Peru-Chile Trench, our observations highlight the role of earthquakes in the regional water cycle, especially in arid environments.

  6. 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.

  7. 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

  8. Watershed geomorphology and snowmelt control stream thermal sensitivity to air temperature

    NASA Astrophysics Data System (ADS)

    Lisi, Peter J.; Schindler, Daniel E.; Cline, Timothy J.; Scheuerell, Mark D.; Walsh, Patrick B.

    2015-05-01

    How local geomorphic and hydrologic features mediate the sensitivity of stream thermal regimes to variation in climatic conditions remains a critical uncertainty in understanding aquatic ecosystem responses to climate change. We used stable isotopes of hydrogen and oxygen to estimate contributions of snow and rainfall to 80 boreal streams and show that differences in snow contribution are controlled by watershed topography. Time series analysis of stream thermal regimes revealed that streams in rain-dominated, low-elevation watersheds were 5-8 times more sensitive to variation in summer air temperature compared to streams draining steeper topography whose flows were dominated by snowmelt. This effect was more pronounced across the landscape in early summer and less distinct in late summer. Thus, the impact of climate warming on freshwater thermal regimes will be spatially heterogeneous across river basins as controlled by geomorphic features. However, thermal heterogeneity may be lost with reduced snowpack and increased ratios of rain to snow in stream discharge.

  9. 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.

  10. Assessing the snowmelt submodel of TETIS within the DMIP2 project

    NASA Astrophysics Data System (ADS)

    Orozco, Ismael; Francés, Félix

    2010-05-01

    Melt modelling is a crucial element in any attempt to predict runoff from snow-covered or glacierised areas, as well as to assess changes in the cryosphere associated with clime change. In mountainous regions, snow and ice significantly affect catchment hydrology by temporarily storing and releasing water on various time scales (Jansson et al., 2003). Hence, success of runoff modelling in such areas largely depends on accurate quantification of the melt process (Hock, 2003). Snowmelt modelling is complex and dependent on elevation, slope, vegetation type, surface roughness, radiation load, and energy exchange at the snow-air interface (Baron, 1992; Barros and Lettenmaier, 1993; Becker et al., 1994; Cline, 1995; Elder et al., 1991). This paper describes the application of the degree-day method for snowmelt-runoff at hourly time discretization, which is implemented in the distributed and conceptually based hydrological model TETIS, as well as the evaluation of results. In the TETIS model the natural basins are discretizated in grid cells according to drainage network. This conceptualization permits all parameters do not lose its physical meaning (Francés et al., 2007). At each cell the main soil properties need to be estimated previously using topographical, environmental, land use, geological and soil maps. The model has been applied to the Sierra Nevada basins, in USA: the American River (886 km2) and the Carson River (922 km2), as a part of the Distributed Model Intercomparison Project, second phase (DMIP2), of the National Oceanic and Atmospheric Administration's National Weather Service (NOAA/NWS), in which we are participating. These basins are geographically close, but their hidrological regimes are quite different: the Carson River is a high altitude basin with a snow dominated regime; while the American River drains an area that is lower in elevation with precipitation falling as rain and mixed snow and rain (Jeton et al., 1996). Details on the basins

  11. 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...

  12. `Hearing' alpine plants growing after snowmelt: ultrasonic snow sensors provide long-term series of alpine plant phenology

    NASA Astrophysics Data System (ADS)

    Vitasse, Yann; Rebetez, Martine; Filippa, Gianluca; Cremonese, Edoardo; Klein, Geoffrey; Rixen, Christian

    2017-02-01

    In alpine environments, the growing season is severely constrained by low temperature and snow. Here, we aim at determining the climatic factors that best explain the interannual variation in spring growth onset of alpine plants, and at examining whether photoperiod might limit their phenological response during exceptionally warm springs and early snowmelts. We analysed 17 years of data (1998-2014) from 35 automatic weather stations located in subalpine and alpine zones ranging from 1560 to 2450 m asl in the Swiss Alps. These stations are equipped with ultrasonic sensors for snow depth measurements that are also able to detect plant growth in spring and summer, giving a unique opportunity to analyse snow and climate effects on alpine plant phenology. Our analysis showed high phenological variation among years, with one exceptionally early and late spring, namely 2011 and 2013. Overall, the timing of snowmelt and the beginning of plant growth were tightly linked irrespective of the elevation of the station. Snowmelt date was the best predictor of plant growth onset with air temperature after snowmelt modulating the plants' development rate. This multiple series of alpine plant phenology suggests that currently alpine plants are directly tracking climate change with no major photoperiod limitation.

  13. 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.

  14. 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.

  15. High Arctic plant phenology is determined by snowmelt patterns but duration of phenological periods is fixed: an example of periodicity

    NASA Astrophysics Data System (ADS)

    Semenchuk, Philipp R.; Gillespie, Mark A. K.; Rumpf, Sabine B.; Baggesen, Nanna; Elberling, Bo; Cooper, Elisabeth J.

    2016-12-01

    The duration of specific periods within a plant’s life cycle are critical for plant growth and performance. In the High Arctic, the start of many of these phenological periods is determined by snowmelt date, which may change in a changing climate. It has been suggested that the end of these periods during late-season are triggered by external cues, such as day length, light quality or temperature, leading to the hypothesis that earlier or later snowmelt dates will lengthen or shorten the duration of these periods, respectively, and thereby affect plant performance. We tested whether snowmelt date controls phenology and phenological period duration in High Arctic Svalbard using a melt timing gradient from natural and experimentally altered snow depths. We investigated the response of early- and late-season phenophases from both vegetative and reproductive phenological periods of eight common species. We found that all phenophases follow snowmelt patterns, irrespective of timing of occurrence, vegetative or reproductive nature. Three of four phenological period durations based on these phenophases were fixed for most species, defining the studied species as periodic. Periodicity can thus be considered an evolutionary trait leading to disadvantages compared with aperiodic species and we conclude that the mesic and heath vegetation types in Svalbard are at risk of being outcompeted by invading, aperiodic species from milder biomes.

  16. `Hearing' alpine plants growing after snowmelt: ultrasonic snow sensors provide long-term series of alpine plant phenology

    NASA Astrophysics Data System (ADS)

    Vitasse, Yann; Rebetez, Martine; Filippa, Gianluca; Cremonese, Edoardo; Klein, Geoffrey; Rixen, Christian

    2016-08-01

    In alpine environments, the growing season is severely constrained by low temperature and snow. Here, we aim at determining the climatic factors that best explain the interannual variation in spring growth onset of alpine plants, and at examining whether photoperiod might limit their phenological response during exceptionally warm springs and early snowmelts. We analysed 17 years of data (1998-2014) from 35 automatic weather stations located in subalpine and alpine zones ranging from 1560 to 2450 m asl in the Swiss Alps. These stations are equipped with ultrasonic sensors for snow depth measurements that are also able to detect plant growth in spring and summer, giving a unique opportunity to analyse snow and climate effects on alpine plant phenology. Our analysis showed high phenological variation among years, with one exceptionally early and late spring, namely 2011 and 2013. Overall, the timing of snowmelt and the beginning of plant growth were tightly linked irrespective of the elevation of the station. Snowmelt date was the best predictor of plant growth onset with air temperature after snowmelt modulating the plants' development rate. This multiple series of alpine plant phenology suggests that currently alpine plants are directly tracking climate change with no major photoperiod limitation.

  17. 'Hearing' alpine plants growing after snowmelt: ultrasonic snow sensors provide long-term series of alpine plant phenology.

    PubMed

    Vitasse, Yann; Rebetez, Martine; Filippa, Gianluca; Cremonese, Edoardo; Klein, Geoffrey; Rixen, Christian

    2017-02-01

    In alpine environments, the growing season is severely constrained by low temperature and snow. Here, we aim at determining the climatic factors that best explain the interannual variation in spring growth onset of alpine plants, and at examining whether photoperiod might limit their phenological response during exceptionally warm springs and early snowmelts. We analysed 17 years of data (1998-2014) from 35 automatic weather stations located in subalpine and alpine zones ranging from 1560 to 2450 m asl in the Swiss Alps. These stations are equipped with ultrasonic sensors for snow depth measurements that are also able to detect plant growth in spring and summer, giving a unique opportunity to analyse snow and climate effects on alpine plant phenology. Our analysis showed high phenological variation among years, with one exceptionally early and late spring, namely 2011 and 2013. Overall, the timing of snowmelt and the beginning of plant growth were tightly linked irrespective of the elevation of the station. Snowmelt date was the best predictor of plant growth onset with air temperature after snowmelt modulating the plants' development rate. This multiple series of alpine plant phenology suggests that currently alpine plants are directly tracking climate change with no major photoperiod limitation.

  18. 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.

  19. 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.

  20. Trends and shifts in streamflow in Hawaii, 1913-2008

    USGS Publications Warehouse

    Bassiouni, Maoya; Oki, Delwyn S.

    2013-01-01

    This study addresses a need to document changes in streamflow and base flow (groundwater discharge to streams) in Hawai'i during the past century. Statistically significant long-term (1913-2008) downward trends were detected (using the nonparametric Mann-Kendall test) in low-streamflow and base-flow records. These long-term downward trends are likely related to a statistically significant downward shift around 1943 detected (using the nonparametric Pettitt test) in index records of streamflow and base flow. The downward shift corresponds to a decrease of 22% in median streamflow and a decrease of 23% in median base flow between the periods 1913-1943 and 1943-2008. The shift coincides with other local and regional factors, including a change from a positive to a negative phase in the Pacific Decadal Oscillation, shifts in the direction of the trade winds over Hawai'i, and a reforestation programme. The detected shift and long-term trends reflect region-wide changes in climatic and land-cover factors. A weak pattern of downward trends in base flows during the period 1943-2008 may indicate a continued decrease in base flows after the 1943 shift. Downward trends were detected more commonly in base-flow records than in high-streamflow, peak-flow, and rainfall records. The decrease in base flow is likely related to a decrease in groundwater storage and recharge and therefore is a valuable indicator of decreasing water availability and watershed vulnerability to hydrologic changes. Whether the downward trends will continue is largely uncertain given the uncertainty in climate-change projections and watershed responses to changes.

  1. 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.

  2. 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.

  3. Global separation of plant transpiration from groundwater and streamflow.

    PubMed

    Evaristo, Jaivime; Jasechko, Scott; McDonnell, Jeffrey J

    2015-09-03

    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.

  4. 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.

  5. 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

  6. Restoration of the Spring Snowmelt Recession Below Dams for Native Species Protection in a Changing Climate

    NASA Astrophysics Data System (ADS)

    Yarnell, S.; Epke, G.; Rheinheimer, D. E.; Viers, J. H.

    2011-12-01

    Within Mediterranean-montane ecosystems, the spring snowmelt recession is a distinct feature of the natural annual hydrograph, providing an ecologically significant bridge between the physical disturbance of winter high flows and the biologically stressful conditions of summer low flows. In regulated systems, the snowmelt recession is often absent as the predictable flows are captured behind dams. While restoration of the spring recession is an identified ecological goal, methods for determining suitable ramping rates to transition from high to low flows are lacking, and the hydropower-related cost of such environmental flows under changing climate conditions is uncertain. Here we summarize a quantitative analysis of the spring recession for selected unregulated locations in the Sierra Nevada, California, USA, using an exponential-based function to describe the rate of change in discharge. Results indicate unimpaired recession rates in the Sierra Nevada are consistent across watersheds. We then apply a modeled recession based on these characteristics to an assessment of suitable instream habitat for a native river-breeding amphibian of concern and find that recession rates can be quantitatively modeled to provide ramping rate conditions suitable for native species. Finally, we evaluate the hydropower-related costs of imposing a springtime weekly ramping rate constraint in a regulated Sierran system under various climate warming scenarios. Results show that generation and revenue costs from a ramping rate constraint are low compared to costs associated with increased minimum instream flows throughout the summer, though with climate warming these hydropower costs become more pronounced. Results from these studies collectively provide resource managers with improved knowledge of river dynamics and help guide the prescription of flow regimes in managed river systems to better sustain aquatic and riparian ecosystems in changing hydroclimatic conditions.

  7. 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.

  8. 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

  9. 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.

  10. Snowmelt and runoff modelling of an Arctic hydrological basin in west Greenland

    NASA Astrophysics Data System (ADS)

    Bøggild, C. E.; Knudby, C. J.; Knudsen, M. B.; Starzer, W.

    1999-09-01

    This paper compares the performance of a conceptual modelling system and several physically-based models for predicting runoff in a large hydrological basin, Tasersuaq, in west Greenland. This basin, which is typical of many Greenland basins, is interesting because of the fast hydrological response to changing conditions. Due to the predominance of exposed bedrock surface and only minor occurrence of sediments and organic soils, there is little restraint to run-off, making the treatment of the snowmelt component of primary importance.Presently a conceptual modelling system, HBV, is applied in Greenland and also in most of the arctic regions of Scandinavia for operational forecasting. A general wish to use hydrological models for other purposes, such as to improve data collection and to gain insight into the hydrological processes has promoted interest in the more physically-based hydrological models. In this paper, two degree-day models, the Danish version of the physically-based SHE distributed hydrological modelling system (MIKE SHE) and the conceptual HBV model are compared with a new model that links MIKE SHE and a distributed energy balance model developed for this study, APUT.The HBV model performs the best overall simulation of discharge, which presently makes it most suited for general forecasting. The combination of MIKE SHE and APUT i.e. a physically based modelling system shows promising results by improving the timing of the initiation of spring flood, but does not perform as well throughout the remaining part of the snowmelt season. The modelling study shows that local parameters such as the snow depletion curve, the temporal snow albedo and perhaps also melt water storage need to be more precisely determined from field studies before physically-based modelling can be improved.

  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. Estimation of the effects of land use and groundwater withdrawals on streamflow for the Pomperaug River, Connecticut

    USGS Publications Warehouse

    Bjerklie, David M.; Starn, J. Jeffrey; Tamayo, Claudia

    2010-01-01

    A precipitation runoff model for the Pomperaug River watershed, Connecticut was developed to address issues of concern including the effect of development on streamflow and groundwater recharge, and the implications of water withdrawals on streamflow. The model was parameterized using a strategy that requires a minimum of calibration and optimization by establishing basic relations between the parameter value and physical characteristics of individual hydrologic response units (HRUs) that comprise the model. The strategy was devised so that the information needed can be obtained from Geographic Information System and other general databases for Connecticut. Simulation of groundwater recharge enabled evaluation of the temporal and spatial mapping of recharge variation across the watershed and the spatial effects of changes in land cover on base flow and surface runoff. The modeling indicated that over the course of a year, groundwater provides between 60 and 70 percent of flow in the Pomperaug River; the remainder is generated by more rapid flow through the shallow subsurface and runoff from impermeable surfaces and saturated ground. Groundwater is recharged primarily during periods of low evapotranspiration in the winter, spring, and fall. The largest amount of recharge occurs in the spring in response to snowmelt. During floods, the Weekeepeemee and Nonnewaug Rivers (tributaries that form the Pomperaug River) respond rapidly with little flood peak attenuation due to flood-plain storage. In the Pomperaug River, flood-plain storage is more important in attenuating floods; abandoned quarry ponds (O&G ponds) adjacent to the river provide substantial flood storage above specific river stages when flow from the river spills over the banks and fills the ponds. Discharge from the ponds also helps to sustain low flows in the Pomperaug River. Similarly, releases from the Bronson-Lockwood reservoir sustain flow in the Nonnewaug River and tend to offset the effect of

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Trends in streamflow, sedimentation, and sediment chemistry for the Wolf River, Menominee Indian Reservation, Wisconsin, 1850-1999

    USGS Publications Warehouse

    Fitzpatrick, Faith A.

    2005-01-01

    Historical trends in streamflow, sedimentation, and sediment chemistry of the Wolf River were examined for a 6-mile reach that flows through the southern part of the Menominee Indian Reservation and the northern part of Shawano County, Wis. Trends were examined in the context of effects from dams, climate, and land-cover change. Annual flood peaks and mean monthly flow for the Wolf River were examined for 1907-96 and compared to mean annual and mean monthly precipitation. Analysis of trends in sedimentation (from before about 1850 through 1999) involved collection of cores and elevation data along nine valley transects spanning the Wolf River channel, flood plain, and backwater and impounded areas; radioisotope analyses of impounded sediment cores; and analysis of General Land Office Survey Notes (1853-91). Trends in sediment chemistry were examined by analyzing samples from an impoundment core for minor and trace elements. Annual flood peaks for the Wolf River decreased during 1907-49 but increased during 1950-96, most likely reflecting general changes in upper-atmospheric circulation patterns from more zonal before 1950 to more meridional after 1950. The decrease in flood peaks during 1907-49 may also, in part, be due to forest regrowth. Mean monthly streamflow during 1912-96 increased for the months of February and March but decreased for June and July, suggesting that spring snowmelt occurs earlier in the season than it did in the past. Decreases in early summer flows may be a reflection earlier spring snowmelt and large rainstorms in early spring rather than early summer. These trends also may reflect upper-atmospheric circulation patterns. The Balsam Row Dam impoundment contains up to 10 feet of organic-rich silty clay and has lost much of its storage capacity. Fine sediment has accumulated for 1.8 miles upstream from the Balsam Row Dam. Historical average linear and mass sedimentation rates in the Balsam Row impoundment were 0.09 feet per year and 1

  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. 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.

  1. Paleoflood investigations to improve peak-streamflow regional-regression equations for natural streamflow in eastern Colorado, 2015

    USGS Publications Warehouse

    Kohn, Michael S.; Stevens, Michael R.; Harden, Tessa M.; Godaire, Jeanne E.; Klinger, Ralph E.; Mommandi, Amanullah

    2016-09-09

    The U.S. Geological Survey (USGS), in cooperation with the Colorado Department of Transportation, developed regional-regression equations for estimating the 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, 0.2-percent annual exceedance-probability discharge (AEPD) for natural streamflow in eastern Colorado. A total of 188 streamgages, consisting of 6,536 years of record and a mean of approximately 35 years of record per streamgage, were used to develop the peak-streamflow regional-regression equations. The estimated AEPDs for each streamgage were computed using the USGS software program PeakFQ. The AEPDs were determined using systematic data through water year 2013. Based on previous studies conducted in Colorado and neighboring States and on the availability of data, 72 characteristics (57 basin and 15 climatic characteristics) were evaluated as candidate explanatory variables in the regression analysis. Paleoflood and non-exceedance bound ages were established based on reconnaissance-level methods. Multiple lines of evidence were used at each streamgage to arrive at a conclusion (age estimate) to add a higher degree of certainty to reconnaissance-level estimates. Paleoflood or nonexceedance bound evidence was documented at 41 streamgages, and 3 streamgages had previously collected paleoflood data.To determine the peak discharge of a paleoflood or non-exceedanc bound, two different hydraulic models were used.The mean standard error of prediction (SEP) for all 8 AEPDs was reduced approximately 25 percent compared to the previous flood-frequency study. For paleoflood data to be effective in reducing the SEP in eastern Colorado, a larger ratio than 44 of 188 (23 percent) streamgages would need paleoflood data and that paleoflood data would need to increase the record length by more than 25 years for the 1-percent AEPD. The greatest reduction in SEP for the peak-streamflow regional-regression equations was observed when additional new basin characteristics were included in the peak-streamflow

  2. Review and analysis of available streamflow and water-quality data for Park County, Colorado, 1962-98

    USGS Publications Warehouse

    Kimbrough, Robert A.

    2001-01-01

    Information on streamflow and surface-water and ground-water quality in Park County, Colorado, was compiled from several Federal, State, and local agencies. The data were reviewed and analyzed to provide a perspective of recent (1962-98) water-resource conditions and to help identify current and future water-quantity and water-quality concerns. Streamflow has been monitored at more than 40 sites in the county, and data for some sites date back to the early 1900's. Existing data indicate a need for increased archival of streamflow data for future use and analysis. In 1998, streamflow was continuously monitored at about 30 sites, but data were stored in a data base for only 10 sites. Water-quality data were compiled for 125 surface-water sites, 398 wells, and 30 springs. The amount of data varied considerably among sites; however, the available information provided a general indication of where water-quality constituent concentrations met or exceeded water-quality standards. Park County is primarily drained by streams in the South Platte River Basin and to a lesser extent by streams in the Arkansas River Basin. In the South Platte River Basin in Park County, more than one-half the annual streamflow occurs in May, June, and July in response to snowmelt in the mountainous headwaters. The annual snowpack is comparatively less in the Arkansas River Basin in Park County, and mean monthly streamflow is more consistent throughout the year. In some streams, the timing and magnitude of streamflow have been altered by main-stem reservoirs or by interbasin water transfers. Most values of surface-water temperature, dissolved oxygen, and pH were within recommended limits set by the Colorado Department of Public Health and Environment. Specific conductance (an indirect measure of the dissolved-solids concentration) generally was lowest in streams of the upper South Platte River Basin and higher in the southern one-half of the county in the Arkansas River Basin and in the South

  3. 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.

  4. Techniques for estimating selected streamflow characteristics of rural unregulated streams in Ohio

    USGS Publications Warehouse

    Koltun, G.F.; Whitehead, Matthew T.

    2002-01-01

    This report provides equations for estimating mean annual streamflow, mean monthly streamflows, harmonic mean streamflow, and streamflow quartiles (the 25th-, 50th-, and 75th-percentile streamflows) as a function of selected basin characteristics for rural, unregulated streams in Ohio. The equations were developed from streamflow statistics and basin-characteristics data for as many as 219 active or discontinued streamflow-gaging stations on rural, unregulated streams in Ohio with 10 or more years of homogenous daily streamflow record. Streamflow statistics and basin-characteristics data for the 219 stations are presented in this report. Simple equations (based on drainage area only) and best-fit equations (based on drainage area and at least two other basin characteristics) were developed by means of ordinary least-squares regression techniques. Application of the best-fit equations generally involves quantification of basin characteristics that require or are facilitated by use of a geographic information system. In contrast, the simple equations can be used with information that can be obtained without use of a geographic information system; however, the simple equations have larger prediction errors than the best-fit equations and exhibit geographic biases for most streamflow statistics. The best-fit equations should be used instead of the simple equations whenever possible.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Trends in Streamflow of the San Pedro River, Southeastern Arizona

    USGS Publications Warehouse

    Thomas, Blakemore E.

    2006-01-01

    Total annual streamflow of the San Pedro River at Charleston in southeastern Arizona (fig. 1) decreased by about 66 percent from 1913 to 2002 (fig. 2). 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. The decreasing trend in streamflow has led to concerns that riparian habitat may be damaged and that overall long-term water supply for a growing population may be threatened. Resource managers and the public have an interest in learning more about the trend and the possible causes of the trend.

  10. HYDRORECESSION: A Matlab toolbox for streamflow recession analysis

    NASA Astrophysics Data System (ADS)

    Arciniega-Esparza, Saúl; Breña-Naranjo, José Agustín; Pedrozo-Acuña, Adrián; Appendini, Christian Mario

    2017-01-01

    Streamflow recession analysis from observed hydrographs allows to extract information about the storage-discharge relationship of a catchment and some of their groundwater hydraulic properties. The HYDRORECESSION toolbox, presented in this paper, is a graphical user interface for Matlab and it was developed to analyse streamflow recession curves with the support of different tools. The software extracts hydrograph recessions segments with three different methods (Vogel, Brutsaert and Aksoy) that are later analysed with four of the most common models to simulate recession curves (Maillet, Boussinesq, Coutagne and Wittenberg) and it includes four parameter-fitting techniques (linear regression, lower envelope, data binning and mean squared error). HYDRORECESSION offers tools to parameterize linear and nonlinear storage-outflow relationships and it is useful for regionalization purposes, catchment classification, baseflow separation, hydrological modeling and low flows prediction. HYDRORECESSION is freely available for non-commercial and academic purposes and is available at Matlab File Exchange (http://www.mathworks.com/matlabcentral/fileexchange/51332-hydroecession).

  11. Understanding and managing the effects of groundwater pumping on streamflow

    USGS Publications Warehouse

    Leake, Stanley A.; Barlow, Paul M.

    2013-01-01

    Groundwater is a critical resource in the United States because it provides drinking water, irrigates crops, supports industry, and is a source of water for rivers, streams, lakes, and springs. Wells that pump water out of aquifers can reduce the amount of groundwater that flows into rivers and streams, which can have detrimental impacts on aquatic ecosystems and the availability of surface water. Estimation of rates, locations, and timing of streamflow depletion due to groundwater pumping is needed for water-resource managers and users throughout the United States, but the complexity of groundwater and surface-water systems and their interactions presents a major challenge. The understanding of streamflow depletion and evaluation of water-management practices have improved during recent years through the use of computer models that simulate aquifer conditions and the effects of pumping groundwater on streams.

  12. 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

  13. WaterWatch - Maps, Graphs, and Tables of Current, Recent, and Past Streamflow Conditions

    USGS Publications Warehouse

    Jian, Xiaodong; Wolock, David; Lins, Harry

    2008-01-01

    WaterWatch (http://water.usgs.gov/waterwatch/) is a U.S. Geological Survey (USGS) World Wide Web site that dis-plays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for the United States. The real-time information generally is updated on an hourly basis. WaterWatch provides streamgage-based maps that show the location of more than 3,000 long-term (30 years or more) USGS streamgages; use colors to represent streamflow conditions compared to historical streamflow; feature a point-and-click interface allowing users to retrieve graphs of stream stage (water elevation) and flow; and highlight locations where extreme hydrologic events, such as floods and droughts, are occurring. The streamgage-based maps show streamflow conditions for real-time, average daily, and 7-day average streamflow. The real-time streamflow maps highlight flood and high flow conditions. The 7-day average streamflow maps highlight below-normal and drought conditions. WaterWatch also provides hydrologic unit code (HUC) maps. HUC-based maps are derived from the streamgage-based maps and illustrate streamflow conditions in hydrologic regions. These maps show average streamflow conditions for 1-, 7-, 14-, and 28-day periods, and for monthly average streamflow; highlight regions of low flow or hydrologic drought; and provide historical runoff and streamflow conditions beginning in 1901. WaterWatch summarizes streamflow conditions in a region (state or hydrologic unit) in terms of the long-term typical condition at streamgages in the region. Summary tables are provided along with time-series plots that depict variations through time. WaterWatch also includes tables of current streamflow information and locations of flooding.

  14. 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.

  15. Snow-melting season CO2 efflux along the trans-Alaska pipeline

    NASA Astrophysics Data System (ADS)

    Kim, Y.; Nakai, T.

    2011-12-01

    This research was conducted to estimate CO2 effluxes in exposed and snow-covered soils along the trans-Alaska pipeline (ca. 660 km) during snow-melting seasons of April 2010 and April-May 2011. In-situ CO2 efflux was measured with a dynamic chamber system that consisted of a chamber (22 cm in diameter and 6 cm high), pump, NDIR (CO2 analyzer), and a laptop computer. Soil temperature and snow depth were measured with a portable thermocouple and from snow pit-wall. The difference in snow-melting season CO2 efflux was remarkably showed in exposed and snow-covered soils of boreal forest and tundra, suggesting the distinctly latitudinal CO2 efflux gradient. Mean CO2 efflux was 0.88±0.51 and 2.4±3.4 gCO2-C/m2/day in soil temperature of -1.8±4.0 and -1.1±3.4 °C during the snow-melting period of 2010 and 2011, respectively. When the snow was disappeared, mean CO2 efflux was 1.3±0.3 and 5.4±3.7 gCO2-C/m2/day for 2010 and 2011; on the other hand, when the seasonal covered snow was melting, mean CO2 efflux was 0.2±0.2 and 0.3±0.3 gCO2-C/m2/day for both years. However, the coastal site near Arctic sea was not still melted, showing much lower CO2 efflux was 0.02±0.02 and 0.08±0.12 gCO2-C/m2/day in soil temperature of -12.4±2.2 and -12.9±3.4 °C for 2010 and 2011, respectively. A relationship between mean CO2 efflux at each site and mean soil temperature at 5 cm below the surface along the trans-Alaska pipeline is a good exponential, which the equation is as follows: CO2 efflux = 885×exp(0.335×Ts) (R2=0.86; p<0.001) and CO2 efflux = 888×exp(0.337×Ts) (R2=0.92; p<0.001) for 2010 and 2011, respectively. CO2 efflux in a white spruce forest during the snow-thawing season was measured in four directions from the bottom stem, suggesting that distinct differences of CO2 efflux between the exposed soil and the snow-covered soil in the four directions. This may be due to the fast decomposition of soil organic carbon and/or active root respiration in the exposed soil

  16. Quantification of uncertainties in snow accumulation, snowmelt, and snow disappearance dates

    NASA Astrophysics Data System (ADS)

    Raleigh, Mark S.

    Seasonal mountain snowpack holds hydrologic and ecologic significance worldwide. However, observation networks in complex terrain are typically sparse and provide minimal information about prevailing conditions. Snow patterns and processes in this data sparse environment can be characterized with numerical models and satellite-based remote sensing, and thus it is essential to understand their reliability. This research quantifies model and remote sensing uncertainties in snow accumulation, snowmelt, and snow disappearance as revealed through comparisons with unique ground-based measurements. The relationship between snow accumulation uncertainty and model configuration is assessed through a controlled experiment at 154 snow pillow sites in the western United States. To simulate snow water equivalent (SWE), the National Weather Service SNOW-17 model is tested as (1) a traditional "forward" model based primarily on precipitation, (2) a reconstruction model based on total snowmelt before the snow disappearance date, and (3) a combination of (1) and (2). For peak SWE estimation, the reliability of the parent models was indistinguishable, while the combined model was most reliable. A sensitivity analysis demonstrated that the parent models had opposite sensitivities to temperature that tended to cancel in the combined model. Uncertainty in model forcing and parameters significantly controlled model accuracy. Uncertainty in remotely sensed snow cover and snow disappearance in forested areas is enhanced by canopy obstruction but has been ill-quantified due to the lack of sub-canopy observations. To better quantify this uncertainty, dense networks of near-surface temperature sensors were installed at four study areas (≤ 1 km2) with varying forest cover in the Sierra Nevada, California. Snow presence at each sensor was detected during periods when temperature was damped, which resulted from snow cover insulation. This methodology was verified using time-lapse analysis and

  17. Using SST, PDO and SOI for Streamflow Reconstruction

    NASA Astrophysics Data System (ADS)

    Bukhary, S. S.; Kalra, A.; Ahmad, S.

    2015-12-01

    Recurring droughts in southwestern U.S. particularly California, have strained the existing water reserves of the region. Frequency, severity and duration of these recurring drought events may not be captured by the available instrumental records. Thus streamflow reconstruction becomes imperative to identify the historic hydroclimatic extremes of a region and assists in developing better water management strategies, vital for sustainability of water reserves. Tree ring chronologies (TRC) are conventionally used to reconstruct streamflows, since tree rings are representative of climatic information. Studies have shown that sea surface temperature (SST) and climate indices of southern oscillation index (SOI) and pacific decadal oscillation (PDO) influence U.S. streamflow volumes. The purpose of this study was to improve the traditional reconstruction methodology by incorporating the oceanic-atmospheric variables of PDO, SOI, and Pacific Ocean SST, alongwith TRC as predictors in a step-wise linear regression model. The methodology of singular value decomposition was used to identify teleconnected regions of streamflow and SST. The approach was tested on eleven gage stations in Sacramento River Basin (SRB) and San Joaquin River Basin (JRB). The reconstructions were successfully generated from 1800-1980, having an overlap period of 1932-1980. Improved results were exhibited when using the predictor variable of SST along with TRC (calibration r2=0.6-0.91) compared to when using TRC in combination with SOI and PDO (calibration r2=0.51-0.78) or when using TRC by itself (calibration r2=0.51-0.86). For future work, this approach can be replicated for other watersheds by using the oceanic-atmospheric climate variables influencing that region.

  18. Estimating River Basin Evapotranspiration From Stream-Flow Time Series

    NASA Astrophysics Data System (ADS)

    Palmroth, S.; Katul, G. G.; Hui, D.; Oren, R.; McCarthy, H. R.; Jackson, R. B.

    2006-12-01

    Estimates of annual evapotransporation (ET) were inverted from continuous stream-flow (Q) records using a simplified watershed water balance and nonlinear reservoir model modified from Brutsaert and Nieber (1977). We focused on the uppermost section (1751 km2 ) of the Neuse River Basin in North Carolina U.S., where the climate is warm and humid and land cover is dominated by forests and agricultural land (totaling ~78% in 1999). We selected 11 U. S. Geological Survey stream-flow measurement stations and reconstructed annual ET from each drainage area, ranging from 26 to 1386 km2, over the period of the operation of each station (10 - 79 years). Scaled to the sub-basin, the stream-flow-based estimates of annual ET (for 2001 - 2004) agreed well with the estimates based on scaled eddy-covariance measured nearby at the Duke Forest AmeriFlux sites. Based on the longest stream-flow datasets, no clear overall trend in Q or the parameters of the reservoir model were found suggesting that the hydrologic properties of the watersheds have changed little over time. Inter-annual variation in precipitation typically explained more than half of the variation in ET while ET was mostly uncorrelated with measured pan evaporation. Thus, annual ET was more closely related to the replenishment of the water storage available for ET than its climatic driving force. We demonstrate that stream-flow records can be useful for providing continuous estimates of ET and, thereby, benchmarks for modeling regional fluxes of water and of other elements, e.g. carbon, that are closely coupled with water.

  19. 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.

  20. 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.

  1. Streamflow of 2015—Water year national summary

    USGS Publications Warehouse

    Jian, Xiaodong; Wolock, David M.; Lins, Harry F.; Brady, Steve

    2016-08-30

    IntroductionThe maps and graphs in this summary describe national streamflow conditions for water year 2015 (October 1, 2014, to September 30, 2015) in the context of the 86-year period 1930–2015, unless otherwise noted. The illustrations are based on observed data from the U.S. Geological Survey’s (USGS) National Streamflow Information Program http://water.usgs.gov/nsip). The period 1930–2015 was used because prior to 1930, the number of streamgages was too small to provide representative data for computing statistics for most regions of the country.In the summary, reference is made to the term “runoff,” which is the depth to which a river basin, State, or other geographic area would be covered with water if all the streamflow within the area during a specified time period was uniformly distributed upon it. Runoff quantifies the magnitude of water flowing through the Nation's rivers and streams in measurement units that can be compared from one area to another.Each of the maps and graphs can be expanded to a larger view by clicking on the image. In all of the graphics, a rank of 1 indicates the highest flow of all years analyzed. Rankings of streamflow are grouped into much-below normal, below normal, normal, above normal, and much-above normal, based on percentiles of flow (greater than 90 percent, 76–90 percent, 25–75 percent, 10–24 percent, and less than 10 percent, respectively) (http://waterwatch.usgs.gov/?id=ww_current). Some data used to produc