Modeling Source-water Contributions to Streamflow along a Stream-Lake-Stream Couplet in a Mountain Watershed Christopher D. Arp Dept. of Biology and The Ecology Center Utah State University GIS in Water Resources term project - November 2002

understanding and predicting how linkages between lakes and streams effect aquatic ecosystem structure and function My Research: hydrologic controls on N cycling hillslope-to-stream scale stream-reach scale watershed scale TOPMODEL GISWR termproject

Watershed Hydrology (TOPMODEL) source-water volumes [V] Mixing Model CTVT = CsurfVsurf + CsoilVsoil + CgwVgw surface runoff (surf) soil water (soil) groundwater (gw) soil water groundwater Nitrogen Flux surface runoff Watershed Chemistry (endmember sampling) source-water concentrations [C] Time Goals Understanding: watershed processes and stream biogeochemistry Application: land-use, aquatic ecosystems, & water quality

TERM PROJECT OBJECTIVES Review of TOPMODEL applications for hydrochemical modeling Acquire necessary data (input & validation) Prepare DEM using TauDEM Analysis of study catchments using tools in ArcGIS & TauDEM

INPUT DATA (spatial) Topography & Hydrography Soils (porosity) Digital Elevation Model (DEM) – 30 m USGS National Elevation Dataset http://edcnts12.cr.usgs.gov/ned Drainage Network National Hydrography Dataset http://nhd.usgs.gov/data.html Soils (porosity) County Soils Database (SSURGO) – NO DICE! http://www.ftw.nrcs.usda.gov/ssurgo_data.html State Soils Database (STATGO) – 1:250,000 NG! http://www.ftw.nrcs.usda.gov/stat_data.html

INPUT DATA (climate) Temperature (daily) Rainfall & on-site weather station (~ 2130 m) Rainfall & Snow Water Equivalents (daily) NRCS SNOTEL STATION (Banner Summit – 312) http://www.wcc.nrcs.usda.gov/snotel/snotel .pl?sitenum=312&state=id Proximity: N44.30, W115.23 (~2150 m)

VALIDATION & CALIBRATION DATA (streamflow)

DEM PROCESSING STEPS Project DEM & NHD datasets – UTM zone 11 Fill Pits, D8 & Dinf Directions, & Contributing Areas River Network Delineation Compare NHD network to DEM generated network, edit channel network and “burn-in” new network Stream delineation and constant drop test Add catchment outlets Delineate catchments and subbasins Calculate wetness index and flow path lengths

Network Discrepancy Edited Network

Raw Spatial Data TOPsetup Ready

What Next? Get soils data Determine which version of TOPMODEL is best for this application Run TOPsetup (if Tarboton version of TOPMODEL is selected) Determine appropriate submodels for ET and snowmelt 5. Run TOPMODEL and compare results to empirical Q data 6. Etc, Etc, Etc