A watershed average slope value is often needed in some hydrologic calculations, for example, Time of Concentration (TOC) estimation using NRCS Lag Time Method. The slope tool in AcrGIS or…
A watershed average slope value is often needed in some hydrologic calculations, for example, Time of Concentration (TOC) estimation using NRCS Lag Time Method. The slope tool in AcrGIS or…
TauDEM, developed by Utah State University is a set of tools to extract and analyze hydrologic information from topography as represented by a DEM. TauDEM is a set of standalone command…
Combined scale factor (CSF) is introduced in this post as well as the difference between ground coordinates (surface coordinates) and grid coordinates. As explained in the post, in a GIS…
Earth is not a perfect globe and its surface is irregular. GIS needs to use coordinates values (X/Y, or Longitude/Latitude) to describe an actual position/feature on earth in software system.…
RAS Mapper of HEC-RAS Version 6 has some basic but useful GIS functions to complete some GIS operations and spatial analyses common to HEC-RAS modeling, although it could not replace…
After a watershed has been delineated using HEC-HMS GIS tools, the subbasins and reaches can be further refined using HEC-HMS merge and split functions. Five subbasins and two reaches were…