It depends on which GIS media you are using. If you use private sourced media, ArcGIS for example, go for the AGWA (Automated Geospatial Watershed Assessment) tool that can integrate watershed analysis through SWAT modeling. Please have a look: Miller, Scott N., et al. "The automated geospatial watershed assessment tool." Environmental Modelling & Software 22.3 (2007): 365-377. And if you are relying on open sourced media, GRASS GIS for example, r.watershed and r.stream modules are extremely helpful for watershed modeling. This might be of your interest in such case: Jasiewicz, JarosŁaw, and Markus Metz. "A new GRASS GIS toolkit for Hortonian analysis of drainage networks." Computers & Geosciences 37.8 (2011): 1162-1173.
It depends on which GIS media you are using. If you use private sourced media, ArcGIS for example, go for the AGWA (Automated Geospatial Watershed Assessment) tool that can integrate watershed analysis through SWAT modeling. Please have a look: Miller, Scott N., et al. "The automated geospatial watershed assessment tool." Environmental Modelling & Software 22.3 (2007): 365-377. And if you are relying on open sourced media, GRASS GIS for example, r.watershed and r.stream modules are extremely helpful for watershed modeling. This might be of your interest in such case: Jasiewicz, JarosŁaw, and Markus Metz. "A new GRASS GIS toolkit for Hortonian analysis of drainage networks." Computers & Geosciences 37.8 (2011): 1162-1173.