Governor Bond Lake TMDL: Appendix A
Final Report 10 September 2002
Soil Loss and
Transport Factor
(KLSCP)
Area weighted average for the entire subwatershed
determined by intersecting land use and soils data sets
using GIS.
GIS Calculated
Groundwater
Recession
(r)
GWLF calibrated to monitored stream flows for
ROP02, ROP04, and ROP05; estimated for other
watersheds based.
Original estimate based on the following formula during
hydrograph regression:
r = ln[flowt1/flowt2]/(t2 - t1) (t2>t1)/day
GWLF - monitored data
calibrated
Rainfall Erosivity Average of Zone 16 and Zone 19, Figure B-1 GWLF
Manual since the watershed is near the boundary.
Cool season (November though April) = 0.13
Warm season (May through October) = 0.28
GWLF Manual:
(Wischmeier and Smith,
1978)
Evapotranspiration
(ET)
Default ET coefficient for land use area and Bond
County Agric. Statistics cropping practices used to
determine weighted average ET for each
subwatershed.
GWLF Manual
Climate Daily Temperature and Precipitation from 1987 through
1999 were reformatted for use in GWLF. Leap year
February 29 values were deleted because the model
could only run 365-day years. The model was
calibrated to 1999 data and simulated for a 13-year run.
Greenville station data was used except where values
were missing. In this case, neighboring station averages
(Vandalia, Carlyle Reservoir, and Hillsboro) were used
(all temperature and 1988 through 1992 precipitation)
Regional Climate Data
Center (MRCC, 2000)
Nutrient Export
Coefficients
FLUX calibrated for subwatersheds ROP02, ROP03,
ROP04, and ROP05. Averages values from these used
for the rest. Grass/Pasture was assumed to have the
same nutrient concentrations as Cropland since these
individual land uses could not be separated out. See text
for more discussion.
GWLF/FLUX Calibrated
Nutrient Washoff
Coefficients and
Accum. Rates
Default GWLF values for urban land uses. GWLF Manual.
Daylight Hours Average of Table B-9 values (GWLF Manual; Mills et.
al, 1985) for 38 and 40o N (Greenville = 38o 53')
GWLF Manual
Growing season Assumed April through October
Sediment
Delivery Ratio
Table values from GWLF manual based on size of
watershed.
GWLF Manual
