Modeling and Software

Some specific applications of hydrologic systems analysis tools:

• SPARROW Modeled Estimates of Nutrient Fluxes Across the U.S.

  The use of a hybrid statistical, GIS, and process-based model (SPARROW) to estimate nutrient fluxes in unmonitored streams throughout the conterminous United States.

• The use of a hybrid statistical / GIS model (WARP) to estimate pesticide concentrations for unmonitored streams throughout the conterminous United States.
• The use of a process-based model (MODFLOW) to help understand sources of contaminants to public-supply wells.
• The use of statistical and GIS tools for classifying watersheds into Hydrologic Landscape Regions.

Spatial datasets developed for hydrologic systems analysis

• Infiltration-excess overland flow estimated by TOPMODEL for the conterminous United States
• STATSGO soil characteristics for the conterminous United States
• Base-flow index grid for the conterminous United States
• ERF1_2 -- Enhanced River Reach File 2.0
• MRB_E2RF1 – Enhanced River Reach File 2.0 modified for NAWQA Major River Basin studies
• Flow characteristics at U.S. Geological Survey streamgages in the conterminous United States
• Estimated mean annual natural ground-water recharge in the conterminous United States
• Saturation overland flow estimated by TOPMODEL for the conterminous United States
• USGS streamgages linked to the medium resolution NHD

Estimating contaminants in unmonitored streams and ground water

• Regression model for explaining and predicting concentrations of dieldrin in whole fish from U.S. streams
• Development and application of a regression equation for estimating the occurrence of atrazine in shallow ground water beneath agricultural areas of the United States

Modeling tools for understanding hydrologic processes

• Factors Influencing Ground-Water Recharge in the Eastern United States
• Precipitation-runoff modeling to compare hydrologic processes governing solute transport in an agricultural watershed in Maryland
• The water, energy, and biogeochemical model (WEBMOD): A TOPMODEL application developed within the Modular Modeling System

Spatial datasets developed for regional and national SPARROW models

• Model Attributes for MRB_E2RF1
• Model Attributes for NHDPlus