North Central Texas Water Quality Project Hydrologic Modeling of Cedar Creek Watershed using SWAT Balaji Narasimhan, Raghavan Srinivasan, Steve Bernardz and Mark Ernst
Cedar Creek Reservoir Total Watershed Area 884 mi 2
North Central Texas Water Quality Project Input Data Sources DEM 30m (USGS) NHD Stream network (USGS) LandUse/LandCover (USGS) 1992 NLCD + 2001 Urban Soil (NRCS) SSURGO (Hunt, Rockwall, Kaufman, and Van Zandt ) Map Information Assembly Display System (MIADS) (Henderson) Dams and Reservoirs (NRCS) NRCS flood prevention dams, farm ponds, and other privately owned dams About 120 dams/ponds Four > 1500 ac.ft Weather (Precipitation, Max. Temp, Min. Temp) (NOAA) NCDC (1950-2002) NEXRAD (1999-2002, when NCDC data is missing) Weather Generator: Solar Radiation, relative humidity, wind speed
North Central Texas Water Quality Project Cedar Creek Watershed Landuse
Total Area: 2612.052 Sq. KM Water 5.54% Wetland 1.84% LandUse Cropland 6.17% Rangeland 1.07% Urban 6.39% Forest 15.48% Cedar Creek 27.74% Kings Creek 33.65% Pasture 63.52% All other creeks 38.60%
North Central Texas Water Quality Project Management Information Cropland Sorghum Conventional Tillage Fertilizer - 67 kg N and 34 kg P per hectare Pastureland In a given year only 50% receive fertilizer (67kg N) Two hay cuttings Fair hydrologic condition Urban Bermuda grass in pervious regions Lawn fertilization (Auto-fertilization - nitrogen stress level of 0.9) Fertilizer assumed: 28-10-10 Data source: Personal communication, County Extension Agents
North Central Texas Water Quality Project Cedar Creek Watershed Soil Types
North Central Texas Water Quality Project Cedar Creek Watershed Water Resources 106 Subbasins 1516 HRU s 4 Reservoirs Major Creeks Big Brushy Kings Creek Cedar Creek Lacey Creek
North Central Texas Water Quality Project Cedar Creek Watershed 10 Weather Stations 9 rain gages 3 temperature gages
North Central Texas Water Quality Project Cedar Creek Watershed 10 Point Source Disarges Patel Terrell Willis Point Kaufman Kemp MaBank Eustace Athens East Cedar Creek Cherokee Shores
SWAT water routing A bucket type approa A = V ( 1000 L ) R = A P D = A z W + 2z btm 2 W 2z btm v = 1 n R 2 / 3 S 1/ 2 P = W + + btm 2 2D 1 z
Disadvantage with a bucket approa The current approa will artificially simulate higher velocity in those small segments and vice versa in large segments Travel time is uncertain Channel erosion will be significantly high in those small segments Natural decay of nutrients in-stream released from point sources during low flow
Modification Iterative Approa q = V ( 24 60 60)
North Central Texas Water Quality Project Flow Calibration and Validation
North Central Texas Water Quality Project
Variable Description Input Value Units File Coefficients related to flow CN2 SCS Runoff curve number (adjustment range) +3 to -3 - *.mgt ESCO Soil evaporation factor 0.85 - *.hru GW_REVAP groundwater re-evaporation coefficient 0.1 - *.gw GW_DELAY Groundwater delay time 135 Days *.gw GWQMN Groundwater storage required for return flow 1.00 mm *.gw REVAPMN Groundwater storage required for reevaporation 1.6000 mm *.gw ALPHA_BF Baseflow alpha factor 0.0420 to 0.2006 Days -1 *.gw CH_N2 Mannings "n" roughness for annel flow 0.075 - *.rte CH_K2 Hydraulic conductivity of annel alluvium 0.1 to 4.0 mm/hr *.rte
Cumulative Monthly Flow at USGS Stream Gage 08062800, Cedar Creek (1969-1987) 900 800 700 Measured Mean = 3.38 cms Predicted = 3.38 cms RMS Error = 2.45 600 m 3 /s 500 400 300 200 100 0 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 Year measured Predicted Calibration: Cedar creek Stream Flow at 08062800 1969-1987 Predicted Flow 50.00 45.00 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 0.00 10.00 20.00 30.00 40.00 50.00 y = 0.8803x R 2 = 0.8191 COE = 0.813 Series1 Linear (Series1) Measured Flow
1400 1200 1000 Cumulative Monthly Flow at USGS Stream Gage 08062900, Kings Creek (1966-1987) Measured Mean = 4.72 cms Predicted = 4.78 cms RMS Error = 3.21 Calibration: Kings Creek 800 m 3 /s 600 400 200 0 1966 1968 1970 1972 1974 1976 1978 1980 1982 1984 1986 Year MEASURED Predicted Stream Flow at 08062900 1966-1987 50.00 Predicted Flow 40.00 30.00 20.00 10.00 0.00 0.00 20.00 40.00 60.00 Measured Flow y = 0.8193x R 2 = 0.8850 COE = 0.832 Series1 Linear (Series1)
FLOW m 3 /s 0.12 0.10 0.08 0.06 0.04 0.02 0.00 SUB 13-KC279 SUB 15 SUB 19 SUB 32-KC987 SUB 34-KC34 SUB 80-KC1388 SUB 45 SUB 52-KC4034 SUB 54 SUB 89-KC274 SWAT MEASURED SWAT: Low flow travel time is about 9.5 Days for about 52KM Dye study results: 10 days to 16 days Highly dependent on flow rate: 0.11 to 0.06 m 3 /s Data source: TRWD, Kings Creek Intensive Study, September 16, 2002
Cumulative Monthly Inflow to Cedar Creek Reservoir (NWS Stations - Enhanced with NEXRAD 1999-2002) 6000 m 3 /s 5000 4000 3000 Measured Mean = 18.37 cms Predicted = 19.18 cms RMS Error = 11.7 Data source: TRWD, Reservoir Water balance 2000 1000 0 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 Year Measured Predicted CC Resv Inflow 1980-02 Predicted Inflow 1.40E+02 1.20E+02 1.00E+02 8.00E+01 6.00E+01 4.00E+01 2.00E+01 0.00E+00 0.00 50.00 100.00 150.00 Measured Inflow y = 0.8666x R 2 = 0.7648 COE = 0.796 Series1 Linear (Series1)
North Central Texas Water Quality Project Channel Erosion and Water Quality Modeling using SWAT Balaji Narasimhan, Peter M. Allen, Mark Ernst, John A. Dunbar, Steve Bernardz, Jeff Arnold, and Raghavan Srinivasan