Presentation on theme: "Tom Craven Matt Simon Anne Trainor. Construct a RHESSys ecohydrologic model for Sandhills Region."— Presentation transcript:
Tom Craven Matt Simon Anne Trainor
Construct a RHESSys ecohydrologic model for Sandhills Region
Sandhills Eight-County Area. Shown on a blue to red color ramp is an 20 foot elevation model of the region. Dashed black lines indicate primary roads, blue lines - major hydrology. Ft. Bragg (right) and Camp Mackall (left) boundaries are shown in fuchsia.
Sub-basin – Cape Fear 14, Part of the Cape Fear River Basin
The entire sub-basin was processed using Arc Hydro in ArcGIS 9.2 using a LiDAR-derived digital elevation model (DEM) created from the North Carolina Floodplain Mapping Program (NCFMP) by the North Carolina Department of Transportation (NCDOT This DEM has a 20 ft spatial resolution or roughly 6 meters.
Reclassified LULC from 15 to 4 classes – Hardwood Deciduous Forest Shrub/Scrub Woody Wetlands – Evergreen Evergreen Forest Mixed Forest – Open/Barren Developed (open space, low and medium intensity) Barren – Herbaceous Grassland Herbaceous Cultivated Crops Emergent Herbaceous Wetlands Open Water
Land Use Type30 m pixelsPercentageCumulative % Evergreen Forest % Grassland/Herbaceous %67.98% Barren Land (Rock/Sand/Clay) %82.91% Woody Wetlands - Deciduous %90.72% Developed, Open Space %96.06% Developed, Low Intensity %97.27% Deciduous Forest %98.35% Mixed Forest %99.38% Shrub/Scrub %99.88% Cultivated Crops120.05%99.93% Emergent Herbaceous Wetlands60.03%99.96% Open Water60.03%99.98% Developed, Medium Intensity40.02%100.00% Totals %
Arcview (Arc2World) to construct world file Template File Parameters Single Soil Type: Sandy Loam Land use: Undeveloped 4 Vegetation Types from 30 m LULC Topography DEM, Hill slope, Wetness index, Slope, Aspect Patch Identification Composite of hill slope, wetness index and LULC Trial 1: 4,161 discrete patch ids Raster calculator: LULC + WI*100 + hill slope * Trial 2: 91 discrete patch ids Raster calculator: LULC + WI*10
Get the model running Incorporate variation in soil types and depths Use explicit routing to examine hydrologic connectivity
Add option to write a logfile with state variables Examine templates and create worldfiles in class for the example watershed Initial gray areas Exact method for creation of useful grids Headers in.def files Going from scratch was difficult but yields a better understanding of the inner workings