Transcript SWAT Modeling of Priority Watershed

Project# 11-900
SWAT Modeling of Priority WatershedPhase II
Dharmendra Saraswat
Assoc. Prof,/Ext. Engineer- Geospatial
501-681-5987 (mobile)
[email protected]
Naresh Pai
Post-Doctoral Associate
Mike Daniels
Extension Water Quality and Nutrient
Management Specialist
Tom Riley
Interim Assistant Director- CED and
Director, Public Policy Center
2013 NPS Conference – September 19, 2013
OBJECTIVE
Project Objective
Prioritize 12-digit HUCs using SWAT model output
2013 NPS Conference – September 19, 2013
BACKGROUND
2
1
3
Phase II
(2011 – 2013)
SWAT Modeling Project
12-digit HUC Prioritization
2013 NPS Conference – September 19, 2013
OVERALL PROJECT APPROACH
Temperature
Precipitation
Calibration/
Validation
PBIAS
NSE
R2
RSR
SWAT
Soils
Land-use/
Point
management
Sources
practices Topography
Prioritization
(Flow-weighted
concentration)
2013 NPS Conference – September 19, 2013
BEST MODELING PRACTICES (BMPS)

Sensitivity analysis

Check potential model problems using SWAT Check*

Annual calibration

Monthly calibration/validation

Qualitative comparison with AWRC data (monthly data from Oct 2011Sept 2012 and then storm samples through March 2013)

Uncertainty analysis

Subwatershed prioritization
*White et al., 2012
2013 NPS Conference – September 19, 2013
PRIORITIZATION RESULTS
Poteau
Critical source area analysis (CSA)
suggested that merely 5% of the
watershed area was responsible for
26%, and 34% of the sediment and
TP overland loads, respectively. In
contrast, the nitrate loading was
relatively uniform in this
watershed.
2013 NPS Conference – September 19, 2013
UNCERTAINTY
Poteau
SWAT model uncertainty band (i.e. 95PPU, shown in green)
at Cauthron and its comparison with the observed (shown in
blue) and best simulated (shown in red) data.
SWAT model uncertainty band (i.e. 95PPU, shown in
green) at Hackett and its comparison with the
observed (shown in blue) and best simulated
(shown in red) data.
Results suggest that 55% of observed data at Cauthron and 49% of observed
data at Hackett, respectively was found within 95% confidence interval of the
best simulations as shown by the 95PPU plot.
2013 NPS Conference – September 19, 2013
PRIORITIZATION RESULTS
Strawberry
Critical source area
analysis (CSA) suggested
that merely 5% of the
watershed area was
responsible for 85%, 22%,
and 16% of sediment, TP,
and NO3-N loads,
respectively.
2013 NPS Conference – September 19, 2013
PRIORITIZATION RESULTS
Upper Saline
Critical source area (CSA)
analysis indicated that merely 5% of
the watershed area was responsible
for 28%, and 13% of the sediment
and TP overland loads, respectively.
In contrast, the nitrate loading was
relatively uniform in this watershed.
2013 NPS Conference – September 19, 2013
COMPARISON WITH MONITORING DATA
Overall Summary
1) the load comparisons were favorable across all three watersheds;
2) The mean concentration comparison during base flow conditions at the selected HUC 12
level showed relations in the ranks of the sites within the Poteau and Upper Saline
Watersheds for NO3-N and TP, but not TSS. The monitoring data and SWAT output
were not related at the Strawberry Watershed.
3) These results increase our confidence in the subwatershed prioritization by SWAT model
for the Poteau and Upper Saline Watersheds, but not necessarily for the Strawberry
Watershed.
Source: Massey et al., 2013
2013 NPS Conference – September 19, 2013
ACKNOWLEDGEMENTS
EPA, Region VI
2013 NPS Conference – September 19, 2013