Topographic Wetness Indexes for the Upper and Lower Colorado River Basins

This U.S. Geological Survey (USGS) data release describes two 30-meter (m) raster datasets of topographic wetness indexes (TWI) for the Upper and Lower Colorado River basins. The data reside in GeoTIFF (Geographic Tagged Imaged File Format) multiplied by 10 and saved as an integer file to reduce space (colorado14_twX100i.tif and colorado15_twiX100.tif). The TWI units are dimensionless. The dataset resides in the Albers96 NAD83 projection. The source data used were 30-meter digital elevation (DEM) models from the NHDplus Version 2 data suite (U.S. Environmental Protection Agency, 2012).