Subwatershed Prioritizationin Arkansas
- A Modeling Approach
Presented by:Dharmendra Saraswat
Co-Authors: N. Pai, M. Daniels, and M. Leh
ANRC Task Force Meeting, September 21, 2010
Reviewed by: U of A Division of AgricultureEnvironmental Task Force
MODELING OBJECTIVETo assist in assessing the relative risk of sub-watersheds (12-digit hydrologic unit code) for sediment and nutrients contribution from selected 8-digit HUC priority watersheds using State-of-the Art modeling techniques
ANRC Task Force Meeting, September 21, 2010
Priority Watersheds 12-digit HUC 12-digit HUC Priority
MODELING TASKSa) Collect and organize watershed specific input data for setting up the Soil and
Water Assessment Tool (SWAT) model
b) Calibrate and validate the SWAT model for flow, sediment, and nutrients (total phosphorus and nitrate-nitrogen)
ANRC Task Force Meeting, September 21, 2010
MODEL PHILOSOPHY
Public Domain, supported by USDA-ARS, Worldwide
Users and developers base, 682 published articles
ANRC Task Force Meeting, September 21, 2010
MODEL PROCESS- LAND PHASEFor smallest modeling scale, SWAT simulates spatially-variable
soil and water processes that influence movement of nutrients and sediment from land to water
(Source: Neitsch et al. 2005)
ANRC Task Force Meeting, September 21, 2010
MODEL PROCESS- LAND PHASEMajor Simulation Elements
Weather Hydrology Plant growth Erosion Nutrients (N, P) Pesticides Management
(Source: Neitsch et al. 2005)
ANRC Task Force Meeting, September 21, 2010
MODEL PROCESS- IN-STREAM
(Source: Neitsch et al. 2005)
ANRC Task Force Meeting, September 21, 2010
MODELING INPUTS- SPATIAL DATA
SWAT 2009
Elevation(DEM-10/30m)
USGS Boundary(12 Digit HUC)
Soil Data(SSURGO)
Landuse(MULTIPLE
YEARS)
Streams(NHD)
NEXRAD RADAR/Weather
gages
ANRC Task Force Meeting, September 21, 2010
MODELING INPUTS- TABULAR DATA
SWAT 2009
Non-Point SourceAgricultural Land-use
practices for each county
Point source discharge
ANRC Task Force Meeting, September 21, 2010
Average daily loadings for:water, sediment, ammonia, Carbonaceous biochemical oxygen demand dissolved oxygen and phosphorus
MODEL EVALUATION PROTOCOL
Six components of model evaluation:
Model examination Algorithm examination Data evaluation: quality of data
Sensitivity analysis: highest influence
Validation: system performance
Uncertainty analysis (recent trends)
(Source: American Society for Testing and Materials, 1984)
ANRC Task Force Meeting, September 21, 2010
WHY TAKE ALL THIS TROUBLE?
Reduce potential modeler bias Provide a road map to follow Allow other to repeat the study Improve acceptance of model
results
ANRC Task Force Meeting, September 21, 2010
1. Arrange simulated annual pollutant concentration
2. Sort low to high
3. Calculate rank
4. Calculate percentile rank
Tied Rank functionality in Excel 2010
Low
To
High
PERCENTILE RANKING
ANRC Task Force Meeting, September 21, 2010
CASE STUDY
Beaver Reservoir
Lake Conway Point Remove (LCPR)
Bayou Bartholomew
Illinois River Drainage Area in Arkansas (IRDAA)
ANRC Task Force Meeting, September 21, 2010
CASE STUDY
ILLINOIS RIVER DRAINAGE AREA
IN ARKANSAS (IRDAA)
ANRC Task Force Meeting, September 21, 2010
MODEL SETUP- COMPARISONModel: SWAT2005DEM: 10 mSoil: SSURGOLand Use: 2006 HRUs: Criteria(10% land use, 5% soil type, 0%
slope)Ponds: 9019 (3831 acres)Study Period:Calibration: 1996-2005(1992-
95)Validation: 2006-2007 Flow at three gages, sediment and nutrients at outlet
Nitrate-nitrogen yield from a few forestry dominated subwatersheds in southern part of IRDAA did not match with expected yield
Lack of all forms of nitrogen data from point sources could result in higher loading from landscape.
ANRC Task Force Meeting, September 21, 2010
Model: SWAT2009DEM: 10 mSoil: SSURGOLand Use: 1992, 1993, 1999,
2001, 2004, and 2006 HRUs: 848Ponds: 9019 (3831 acres)Study Period:Calibration: 1996-2005(1992-
95)Validation: 2006-2008 Flow at total seven gages, sediment and nutrients at three
MODEL SETUP- COMPARISON
Few studies have used watershed models in spatially distributed fashion
Spatially distributed calibration and validation account for hydrologic patterns in subwatersheds*
* Qi and Grunwald, 2005
ANRC Task Force Meeting, September 21, 2010
Weather
* NOAA -NWS
DATA USED
NEXT GENERATION RADAR (NEXRAD)
ANRC Task Force Meeting, September 21, 2010
ETF Recommendation:
4%, 21%, and 75% for ammonia-, organic-, and nitrate-nitrogen- based on ETF recommendation
Point Source Loading
DATA USED
ANRC Task Force Meeting, September 21, 2010
Poultry litter application adjusted
-Litter application rate adjusted for type of grasses and temporally as well*-Cool-season: 2 ton/ac Warm season: 3 ton/ac-January 2004 onwards, rate declined to 1 ton/ac
Management Data
DATA USED
(*Sharpley et al., 2009)
ANRC Task Force Meeting, September 21, 2010
CALIBRATION/VALIDATION
Subwatershed#16- ~44%, (80%) #19- ~60% (~89%), #18- 24% (~65%)
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Sediment
SUBWATERSHED IDENTIFICATION
Highest priority:
Subwatershed#
Urban%
Pasture%
Forest%
1 44.3 35.5 14.6
2 5.3 62.1 24.9
4 13.9 67.7 14.1
5 31.1 54.5 10.9
12 5.3 56.9 33.4
23 46.0 35.9 12.7
Soil under Hydrologic Group C & D- 73.4%)
ANRC Task Force Meeting, September 21, 2010
HOC, MFL, LOC, SC,MC,SC
Subwatershed#
Urban%
Pasture%
Forest%
7 3.9 58.9 32.1
11 2.5 36.1 58.7
15 1.5 27.9 67.2
16 5.3 40.3 47.7
25 0.5 22.8 73.5
Percentile Approach – Sediment
SUBWATERSHED IDENTIFICATION
Lowest priority:
Slopes > 8%- 46.4% Soil under Hydrologic Group C & D- 67.6%)
ANRC Task Force Meeting, September 21, 2010
UBC, CH, LW, UMF, UEC
Subwatershed#
Urban%
Pasture%
Forest%
2* 44.3 35.5 14.6
3 7.2 52.8 34.8
4 13.9 67.7 14.1
5* 31.1 54.5 10.9
18* 11.4 56.3 25.8
23* 46.0 35.9 12.7
Percentile Approach – Total Phosphorus
SUBWATERSHED IDENTIFICATION
Highest priority:
*Point source affected *23- 303(d) listSoil -C & D- 74%
ANRC Task Force Meeting, September 21, 2010
MFC, HFC, LOC,SC, GC, SC
Subwatershed#
Urban%
Pasture%
Forest%
6 4.7 35.6 55.6
11 2.5 36.1 58.7
15 1.5 27.9 67.2
16 5.3 40.3 47.7
Percentile Approach – Total Phosphorus
SUBWATERSHED IDENTIFICATION
Lowest priority:
ANRC Task Force Meeting, September 21, 2010
LF, CH, LW, UMF
Subwatershed#
Urban%
Pasture%
Forest%
2 5.3 62.1 24.9
4 13.9 67.7 14.1
5* 31.1 54.5 10.9
6 4.7 35.6 55.6
7 3.9 58.9 32.1
Percentile Approach – Nitrate-Nitrogen
SUBWATERSHED IDENTIFICATION
Highest priority:
*point source affected, 5 is in 303(d) for nitrate Slopes > 8%- 9.6%
ANRC Task Force Meeting, September 21, 2010
MFC, LOC, SC, LF, UBC
Percentile Approach – Nitrate-Nitrogen
SUBWATERSHED IDENTIFICATION
Lowest priority:
Subwatershed#
Urban%
Pasture%
Forest%
9 2.0 38.1 55.9
21 33.7 29.1 29.4
22 40.5 28.7 21.5
26 3.2 36.6 54.6
27 2.2 39.6 54.3
ANRC Task Force Meeting, September 21, 2010
CASE STUDY
BEAVER RESERVOIR WATERSHED
(BRW)
ANRC Task Force Meeting, September 21, 2010
Model: SWAT2009Delineation: USGS 12-digit HUCDEM: 30 mSoil: SSURGOLand Use: 1992, 1999, 2001, 2004,
and 2006 Subwatersheds: 76HRUs: 2199(5% land use, 10% soil type, 0% slope)Ponds: 6100 (4857 acres)Study Period:Calibration: 1996-2005 (2003-2005)Validation: 2006-2008 Point Sources: 23
MODEL SETUP
ANRC Task Force Meeting, September 21, 2010
Weather
* NOAA -NWS
DATA USED
NEXT GENERATION RADAR (NEXRAD)
ANRC Task Force Meeting, September 21, 2010
MONITORING GAGES
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Sediment
SUBWATERSHED IDENTIFICATION Highest priority:
Subwatershed#
Forest%
Pasture%
Urban%
1* 49 38 58* 65 16 615 41 47 216 43 46 117 65 21 246 57 20 1647 49 16 2959 62 29 160 73 19 161 70 23 162 47 39 663 63 28 264* 51 31 1066 37 53 267 57 34 3
ANRC Task Force Meeting, September 21, 2010
West Fork - 303(d) – sediment since 1998 , TMDL
* PS
Percentile Approach – Sediment
SUBWATERSHED IDENTIFICATION Lowest priority:
Subwatershed#
Forest%
Pasture%
Urban%
2* 38 47 47 45 41 2
10 60 28 012 61 11 920 80 7 022 84 1 224 76 14 426 82 4 227 58 3 532 56 29 434 83 10 241 70 20 144 73 19 145 57 32 271 80 11 4
* flatter topography results in lower sediment loss
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Total P
SUBWATERSHED IDENTIFICATION Highest priority:
Subwatershed#
Forest%
Pasture%
Urban%
3* 24 57 64 21 61 26 26 52 3
8* 65 16 69 37 46 411 48 35 213 61 7 1415 41 47 216 43 46 117 65 21 245 57 32 263 63 28 264* 51 31 1065 43 45 466 37 53 2
* Point source affected
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Total P
SUBWATERSHED IDENTIFICATION Lowest priority:
Subwatershed#
Forest%
Pasture%
Urban%
7 45 41 222 84 1 224 76 14 426 82 4 232 56 29 435 80 13 136 84 11 139 79 14 140 73 18 142 72 18 169 91 5 071 80 11 472 81 8 673 95 3 074 95 3 175 90 7 1
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Nitrogen-N
SUBWATERSHED IDENTIFICATION Highest priority:
Subwatershed#
Forest%
Pasture%
Urban%
1* 49 38 53 24 57 64 21 61 25 45 40 26 26 52 38* 65 16 69 37 46 410 60 28 011 48 35 216 43 46 117 65 33 245 57 32 2
64* 51 31 1065 43 45 466 37 53 2
* Point source affected
ANRC Task Force Meeting, September 21, 2010
SUBWATERSHED IDENTIFICATION
Subwatershed#
Forest%
Pasture%
Urban%
2 38 47 420 80 7 122 84 1 235 80 13 136 84 11 140 73 18 151 82 12 152 50 30 953 82 13 156 83 12 069 81 12 171 80 11 473 95 3 074 95 3 175 90 7 176 88 7 2
Percentile Approach – Nitrogen-N Lowest priority:
ANRC Task Force Meeting, September 21, 2010
CASE STUDY
LAKE CONWAY POINT REMOVE
WATERSHED (LCPRW)
ANRC Task Force Meeting, September 21, 2010
Model: SWAT2009Delineation: USGS 12-digit HUCDEM: 10 mSoil: SSURGOLand Use: 1999, 2004, and 2006 Subwatersheds: 29HRUs: 2668(0% land use, 5% soil type, 0% slope)Ponds: 6100 (4857 acres)Study Period:Calibration: 2001-2005(Flow)Validation: 2006-2008 (Flow)Point Sources: 34
MODEL SETUP
ANRC Task Force Meeting, September 21, 2010
LEAST MONITORED, MOST RAINGAGES
Weather
DATA USED
ANRC Task Force Meeting, September 21, 2010
Row Crops : Dominant Crop- Soybean
Management Data
DATA USED
Date Operation Rate
May 1 - May 15Tillage couple days before
planting
Disk 2X and
Float 1X
May 1 - May 15 Planting
May 15 - May 30 Fertilization with 0-0-60 100 lb/acre
May 15 - July 15Pesticide glyphosate once per
month 1 lb/acre/month
July 15 - Sep 15 Irrigation ~3 inches/month
Oct 1 - Oct 20 Harvest and kill
ANRC Task Force Meeting, September 21, 2010
Arkansas River as Inlet
DATA USED
USGS gauge near Dardanelle (# 07258000)
Stage-Discharge relationship:Discharge (cfs) = 7408 x Stage (feet) - 30234; R2 = 0.77
+/- 23% error in estimating missing data should be expected (J.E. Funkhouser, USGS)
ANRC Task Force Meeting, September 21, 2010
CALIBRATION/VALIDATION
Flow calibration: 2001-2005, Validation: 2006-2008 Land Use of covered subwatersheds: Forests: 61.7% - 98.4% Pasture: 1.2% - 35.2% Urban: 0.1% - 2.7%
Forest (~54%) and Pasture (~22%)
Flow missing: October 2004- September 2005 October 2007 – September 2008
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Sediment
SUBWATERSHED IDENTIFICATION
Highest priority:
Subwatershed#
Forest%
Crop%
Pasture%
Urban%
14 20 44.6 20.4 5.518 58.8 - 16.9 3.925 39.3 - 39.1 1626 36.2 - 29.6 5.828 14.4 44.7 30.1 9.429 42.7 17.8 23.4 10.8
ANRC Task Force Meeting, September 21, 2010
Subwatershed #18- Beaverdam Creek
Percentile Approach – Sediment
SUBWATERSHED IDENTIFICATION
Lowest priority:
Subwatershed#
Forest%
Crop%
Pasture%
Urban%
1 76.8 - 20.6 1.62 98.4 - 1.2 0.13 64.2 - 29.0 3.24 52.5 - 35.2 3.8
19 72.8 - 15.2 5.3
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Total Phosphorus
SUBWATERSHED IDENTIFICATION
Highest priority:
Subwatershed#
Forest%
Crop%
Pasture%
Urban%
14 20 44.6 20.4 5.518* 58.8 - 16.9 3.925 39.3 - 39.1 16.026 36.2 - 29.6 5.828 14.4 44.7 30.1 9.429 42.7 17.8 23.4 10.8
Soils C & D *Low streamflow
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Total Phosphorus
SUBWATERSHED IDENTIFICATION
Lowest priority:
Subwatershed#
Forest%
Crop%
Pasture%
Urban%
1 76.8 - 20.6 1.62 98.4 - 1.2 0.14 52.5 - 35.2 3.87 66.1 - 31.1 1.99 75.0 - 23.4 1.1
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Nitrate-Nitrogen
SUBWATERSHED IDENTIFICATION
Highest priority:
Subwatershed#
Forest%
Crop%
Pasture%
Urban%
6 33.3 8.6 31.6 20.014 20.0 44.6 20.4 5.517 33.2 - 26.1 35.8
19* 72.8 - 15.2 5.325 39.3 - 39.1 16.026 36.2 - 29.6 5.8
#6- Whig Creek (10 mi)#17- City of Conway WWTP
ANRC Task Force Meeting, September 21, 2010
Subwatershed#
Forest%
Crop%
Pasture%
Urban%
2 98.4 1.2 0.14 52.5 35.2 3.8
15 69.9 - 26.6 2.616 46.1 - 45.5 6.229 42.7 17.8 23.4 10.8
Percentile Approach – Nitrate-Nitrogen
SUBWATERSHED IDENTIFICATION
Lowest priority:
ANRC Task Force Meeting, September 21, 2010
CASE STUDY
BAYOU BARTHOLOMEWWATERSHED (BBW)
ANRC Task Force Meeting, September 21, 2010
Model: SWAT2009Delineation: USGS 12-digit HUCDEM: 10 mSoil: SSURGOLand Use: 1992, 1999, 2004, and
2006 Subwatersheds: 44HRUs: 3657(0% land use, 5% soil type, 0% slope)Study Period:Calibration: 1996-2005Validation: 2006-2008 (2004-
2008)-PortlandPoint Sources: 9
MODEL SETUP
ANRC Task Force Meeting, September 21, 2010
DATA USEDSub
watershedWET_MXS
A (ha)WET_NS
A (ha)WET_MXVO
L (m3)WET_NVO
L (m3)WET_F
R1 286 86 1,432,403 429,721 0.042 2,550 765 12,751,107 3,825,332 0.273 716 215 3,579,180 1,073,754 0.094 1,078 323 5,391,309 1,617,393 0.166 1,206 362 6,028,520 1,808,556 0.167 802 241 4,009,672 1,202,902 0.139 1,024 307 5,119,612 1,535,884 0.15
10 767 230 3,837,069 1,151,121 0.1011 678 203 3,391,550 1,017,465 0.0612 902 271 4,510,018 1,353,005 0.1713 1,841 552 9,205,229 2,761,569 0.1714 136 41 681,884 204,565 0.0118 3,423 1,027 17,113,701 5,134,110 0.2319 2,368 710 11,838,890 3,551,667 0.2222 955 286 4,774,685 1,432,406 0.1023 1,724 517 8,621,501 2,586,450 0.1525 1,410 423 7,048,546 2,114,564 0.1426 847 254 4,236,976 1,271,093 0.0627 1,412 424 7,062,041 2,118,612 0.1530 1,260 378 6,298,187 1,889,456 0.1631 2,077 623 10,385,029 3,115,509 0.1837 1,080 324 5,398,067 1,619,420 0.1043 1,365 410 6,826,668 2,048,000 0.2444 2,395 718 11,972,565 3,591,770 0.35
2001 NLCD land use map 24 of the 44 subwatersheds in BBW had some wetland surface area
ANRC Task Force Meeting, September 21, 2010
NEXRAD
Weather
* NOAA -NWS
DATA USED
ANRC Task Force Meeting, September 21, 2010
Percentile Approach – Sediment
SUBWATERSHED IDENTIFICATION
ANRC Task Force Meeting, September 21, 2010
Preliminary Results
SUBWATERSHED IDENTIFICATION
ANRC Task Force Meeting, September 21, 2010
Preliminary Results
Percentile Approach – Total Phosphorus
Percentile Approach – Nitrate-Nitrogen
SUBWATERSHED IDENTIFICATION
ANRC Task Force Meeting, September 21, 2010
Preliminary Results
OVERALL SUMMARY
State of the art modeling and latest data was used for calibrating and validating SWAT model Total number of gages utilized varied from one to seven in different selected watersheds NEXRAD data used for precipitation as per availabilityModel outputs such as, total flow, surface flow, base flow, sediment, nitrate-nitrogen, and total phosphorus were rigorously evaluated using latest performance criteria In most of the subwatersheds, generally land use, soils, and slope association seen with high/low concentrations for water quality constituents
ANRC Task Force Meeting, September 21, 2010
OVERALL SUMMARY..CONTD.
Uncertainty estimation to assess risk associated with model outputs is gaining ground. Quantification of input data uncertainty is desirable to assess model performance The model output has been used to rank subwatersheds on a relative basis. Absolute conc. of water quality constituent may not be of concern Data gaps noticed in LCPR It is encouraged that modeling results are also compared with other local information for decision making purposes Monitoring and Modeling are complimentary and monitoring data is required for having confidence in modeling results
ANRC Task Force Meeting, September 21, 2010
ACKNOWLEDGMENTS
ANRC Task Force Meeting, September 21, 2010
Dr. Robert (Bob) Morgan, Beaver Water District
Dr. Srinivasan (Srini) Raghavan
Dr.(s) Jeff Arnold, Mike White and Nancy Sammons
Dr. Amy Apon and Mr Jeff Pummil,UA High Performance Computing Center