AGWA Automated Geospatial Watershed Assessment GIS-based Hydrologic Modeling

AGWA Automated Geospatial Watershed Assessment: GIS-based Hydrologic Modeling Tool for Watershed Assessment and Analysis © Copyright Adriel Heisey

Training • Trainers: Dave Goodrich – ARS Phil Guertin – UA Shea Burns – UA/ARS Russ Lyons - UA • Presentations Introduction Advanced Modeling Concepts Fire Effects and Modeling • Training Modules Introduction – San Pedro Example Post-Fire Assessment – Aspen Fire Post-Fire Rehabilitation

AGWA Goals • Process-based tool to - Consequences of historical watershed changes - Identify locations for follow-up targeted ambient monitoring - Assist in stressor and source identification - Evaluate effectiveness of management actions • Operate with readily available GIS data - USGS DEMs (DEMs in ESRI Grid Format) - STATSGO, SSURGO, FAO soils - NALC, NLCD, GAP land cover/use – users can define their own • Applicable across a range of geographies - AZ, OR, NV, NY, VA, WY, MT, Mexico, Kenya, Israel, S. Africa • Applicable to multiple spatial and temporal scales • Both Stand-alone and Web application • Target audience - Researchers - Resource Managers and Decision Makers - Community-based Stakeholders

AGWA – Basics • • Endpoints: runoff, sediment, nitrogen & phosphorus Simple, direct method for model parameterization Provide repeatable results for relative change assessments Two hydrologic models to address multiple scales – SWAT for large basins, daily time steps – KINEROS for small basins, sub-hour time steps – RHEM and WEPP for hillslopes (New) • Basic GIS functionality – watershed delineation – single or multiple pour points – watershed discretization – simple, direct method for model parameterization – execute the models – visualize results spatially and difference results across multiple simulations

Soil Water and Assessment Tool (SWAT) • • • Daily time step Distributed: empirical and physically-based model Curve-number based infiltration – USLE erosion Hydrology, sediment, nutrient, and pesticide yields Larger watersheds (< 1, 000 km 2, up to a HUC 8) Similar effort used by BASINS Abstract Routing Representation 71 to next channel 73 73 71 73 channel 73 pseudochannel 71

Kinematic Runoff and Erosion Model (KINEROS 2) • Event-based (< minute time steps) • Distributed: physically-based model with dynamic routing – both for overland flow and erosion • Has been used in urban environments • Hydrology, erosion, sediment transport (plus N&P with OPUS version) • Smaller watersheds (< 100 -200 km 2, up to a HUC 10) Abstract Routing Representation 71 71 73 72 74

Excess Runoff From a Plane rainfall intensity (i) ¶h + ¶Q = i f ¶t ¶x - KINEROS flow depth (h) Finite difference step length (dx) infiltration (f) q Other Factors interception hydraulic roughness rain splash erosion soil cohesion (erodibility) channel element Q Zones of aggregation and degradation can be define.

New Features and Capabilities • Incorporation of the Water Erosion Prediction Project Model (WEPP) and the Rangeland Hydrology and Erosion Model (RHEM) into KINEROS. – Detailed representation of hillslope elements (geometry, soil, vegetation) – Parameters are available for most agricultural (WEPP) and rangeland (RHEM) types. – Seamless integration between hillslope erosion modeling and sediment transport. – Ability to “switch” models based on land cover being developed.

AGWA Conceptual Design: Inputs and Outputs Watershed Delineation using Digital Elevation Model (DEM) Hillslope Watershed Characterization (model elements) + Intersect model elements with Soils Output results that can be displayed in Land AGWA Cover KINEROS Outputs SWAT Outputs Channel Infiltration (m 3/km) Precipitation (mm) Plane Infiltration (mm) ET (mm) Runoff (mm or m 3) Percolation (mm) Sediment yield (kg) Channel Disch. (m 3/day) Peak flow (m 3/s or mm/hr) Transmission loss (mm) Channel Scour (mm) Water yield (mm) Sediment discharge (kg/s) Sediment yield (t/ha) Rain (Observed or Design Storm) Results Run model and import results

Automated Watershed Characterization Øthe influence of CSA on watershed complexity CSA: 2. 5% (6. 9 km 2) 44 watershed elements 29 channel elements CSA: 5% (13. 8 km 2) 23 watershed elements 15 channel elements Note channel initiation Point changing with CSA km 2) CSA: 10% (27. 5 11 watershed elements 7 channel elements CSA: 20% (55 km 2) 8 watershed elements 5 channel elements N 0 5 10 km

Characterizing the Watershed • Homogeneous planes • Hydrologic parameters represent intersections of topo. , cover, soil • Information loss as f (geometric complexity) • Scaling issues • Assigned the weighted average Watershed modeling relies on condensing spatial data into appropriate units for representing processes leaves plenty of room for error!

Watershed Configuration for SWAT Ø channel and subwatershed hydrology Abstract Routing Representation 64 14 to channel 64 11 14 11 21 channel 14 74 84 24 31 pseudochannel 11 94 44 34 N 41 54 51 0 10 20 km

Watershed Configuration for KINEROS Ø upland, lateral and channel elements in cascade 74 73 72 74 5 km 71 0 N 72 73 71 Abstract Routing Representation

Sample Configuration - KINEROS N STATSGO ID: AZ 061 Grassland & desertscrub Moderate relief Contributing Source Area: 2000 acres - ~5% of total watershed area 33 planes - 7 upland elements - 25 lateral element 19 channels Watershed ID: 73 Area: 7. 45 km 2 Slope: 3. 53 % Width: 945 m Length: 7876 m Interception: 2. 60 mm Cover: 13. 70 % Manning's n: 0. 052 Pavement: 0. 00 % Splash: 24. 91 Rock: 0. 43 Ks: 6. 67 mm/hr Suction: 115 mm Porosity: 0. 459 Max saturation: 0. 93 Cv of Ks: 0. 95 Sand: 50 % Silt: 33 % Clay: 17 % Distribution: 0. 30 Cohesion: 0. 006

AGWA Arc. GIS 9. x Interface

San Pedro River, AZ – AGWA Example

Kepner et al. , EPA NERL/ESD http: //www. epa. gov/nerl 1/land sci/san pedro. htm

Change in Land Cover Extent

Human Use Index 1973 1997 Area near Sierra Vista, AZ Fast-growing city Courtesy Bill Kepner, US-EPA

Spatial and Temporal Scaling of Results Ø Using SWAT and KINEROS for integrated watershed assessment Ø Land cover change analysis and impact on hydrologic response Upper San Pedro River Basin High urban growth 1973 -1997 Sierra Vista Subwatershed KINEROS Results Concentrated urbanization ARIZONA Phoenix # N # Tucson SONORA Water yield change between 1973 and 1997 <<WY >>WY SWAT Results 1997 Land Cover Forest Oak Woodland Mesquite Desertscrub Grassland Urban

Simulated Runoff From the Small Watershed Near Sierra Vista KINEROS model runs for rainfall events 12 0. 12 1997 0. 08 1973 0. 04 Runoff (mm/hr) 1997 8 1973 4 0 0 0 100 200 300 Time (min) 5 -year, 30 -minute rainfall 400 0 100 200 300 Time (min) 100 -year, 60 -minute rainfall 400

Output – Tools for Water Quality Planning 3 0 3 6 Miles Total Erosion for 5 year Event Low Medium High 4 0 4 8 Miles 20 0 20 Miles TMDL Priority LOW MEDIUM N W E S

Management Toolkit • • Use of vegetation monitoring data for model parameterization Land Cover Modification Tool Livestock Management (fencing, water, stocking) Stock ponds/ reservoirs – Wetlands (new) Buffer strips or filter strips (KINEROS) Post-Fire effects LID BMPs (new) Multi-watershed analysis

Land-Cover Modification Tool Allows user to specify type and location of land-cover alterations by either drawing a polygon on the display, or specifying a polygon map Types of Land-Cover Changes: • Change entire user-defined area to new land cover • Change one land-cover type to another in user-defined area • Change land-cover type within user-supplied polygon map • Create a random land-cover pattern • e. g. to simulate burn pattern, change to 64% barren, 31% desert scrub, and 5% mesquite woodland

Wallow Fire, Arizona Phoenix Tucson South Fork Little Colorado River Nutrioso Creek Centerfire Creek-San Francisco River Middle Black 2. 8” 25 year 6 hour event Upper Eagle Creek Upper Blue River Peak Flow (cfs) Sediment Yield (tons/ac) Total Sediment (tons) Percent Pre-fire Post-fire Change 4268. 73 12651. 49 196. 38 1. 19 3. 73 213. 59 113566. 70 356133. 49 213. 59

Worldwide Interest Google Analytics – visits to AGWA website since November, 2007 • 4, 698 registered users based on downloads • 6 continents and 159 countries

AGWA Information • AGWA Web Page: documentation, software, and publications - http: //www. tucson. ars. ag. gov/agwa/ - http: //www. epa. gov/nerlesd 1/land-sci/agwa/ • Versions - Arcview 3. x - Arc. GIS 9. 0, 1, 2, 3 - Arc. GIS 10. 0 - Dot. AGWA 1. x - Below MS-Win 7

AGWA – Why use it? • Hydrology and Erosion modeling in the same place • Can be applied across a range of scales (hillslope HUC 8) • Models have been used and tested in different geographies • Parameterization without calibration – can be used on ungaged watersheds. – • Best for Relative Change Analysis R&D – developing model parameters/tools to evaluate the impact of changing watershed conditions – – Urban Growth – Increase in Impervious Area – LID BMPs Rangeland Conditions – Change in Vegetation Cover Energy Develop – Increase Soil Disturbance, Salt Movement Wildland Fire – Fire Severity – Increase in Soil Disturbance

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