River stage-specific GIS data layers depicting floodplain inundation in the lower Trinity River of Texas

This dataset features inundated areas at discharges from 15,000 cfs to 100,000 cfs. The spatial extent for floodplain inundation modeling in the lower Trinity River was from Romayor, Texas, to approximately Moss Bluff, Texas. River sections were modeled using steady flow conditions. For the upper section, discharge and stage were both available for the two gages (Romayor USGS 08066500 and Liberty USGS 08067000). For the lower section, the Moss Bluff gage (USGS 08067100) is tidally-influenced, so gage height didn’t correspond to upstream changes in discharge. To model river stage specific inundation for the upper section, discharge for each Landsat 8 overpass date was entered as the upstream condition and the corresponding water surface elevation (WSE; gage height, adjusted for local datum) was entered as the downstream constraint. The lower section, from Liberty to Moss Bluff implemented discharge as the upstream condition and normal depth was used as the downstream constraint. Both models were run using different upstream discharge values until modeled WSE most closely matched observed WSE. The two sections exhibited overlap between the bottom of the upper section and the top of the lower section so two shapefiles were created by clipping the inundation outputs at their intersection along U.S. Highway 90 (at Liberty gage). The clipped raster sections were merged to create a seamless output of stage-specific floodplain inundation.