1. Application of GIS and Terrain Analysis to Watershed Model Calibration for the CHIA Project Sam Lamont Robert Eli Jerald Fletcher

2. Background  CHIA: Cumulative Hydrologic Impact Assessment of a mine site  Required of WVDEP, for each proposed mine permit  Surface and groundwater quality and quantity

3. WVU’s Role  Ultimate goal: Graphical tool to simulate pre- and post-mining conditions  Water quantity: Calibrate watershed model (HSPF) to 235 basins in WV

4. 235 Study Watersheds and Their Outlets

5. BASINS-GIS Framework ArcView based environment for display and analysis of watershed features Develops input files for HSPF - watershed file (landuse, slope, area) - stream network - reach attributes - point sources This project: WCMS

6. HSPF: Hydrologic Systems Program - Fortran  Continuous Calculates water balance for each time step R = P – ET – IG – S where: R = Runoff P = Precipitation ET = Evapotranspiration IG = Deep/Inactive Groundwater S = Change in soil storage  Surface and sub-surface hydrology  Inputs = Precip, PET, Temp  Output = Simulated flow

7. Modeled Precipitation Grid - Hourly Precip - 1948 – 2002 - 5 km resolution

8. How HSPF Represents a Watershed Example: - 5 Sub-watersheds - 5 Stream reaches (Storage-Outflow routing) - Land use types Forest (Steep,Moderate, Mild) Shrub-land Pasture/Grassland Urban Mine Barren Row Crop Wetland Surface Water Outlet point Watershed boundary Flow Direction Stream reach

9. Percent Slope Distribution

10. 5 Calibration Watersheds

11. Model Calibration  Trial and error: 1. Run Model 2. Compare output 3. Adjust parameters 4. Repeat  Other software assists this process

12. HSPEXP: Calculates error statistics, provides advice, plots

13. Typical Results: Tygart Valley River at Elkins

14. Further Proposed Terrain Analysis for Calibration Improvement Hoes does watershed shape and structure relate to hydrology? Hoes does watershed shape and structure relate to hydrology? Searching for an index defining hydrologic characteristics. Searching for an index defining hydrologic characteristics. Some examples…

15. Topographic Index  Beven and Kirkby, 1979 TI = ln(a/tanB) a = area B = slope (relative wetness) Example: Abes Run, Canaan Valley

16. Rugosity-Surface Area/Planar Area

17. Drainable Volume - Volume of watershed above a particular elevation

18. Conclusion Future steps: - Fine-tune calibration: Continue searching for patterns - Validate model - Mine site modeling - Link with WCMS

19. Questions ?