Publication Date



GIS, Linear Geomorphological Model (LGM), GIUH


Rainfall is converted into runoff and reaches the river and it becomes river flow. Geomorphological Instantaneous Unit Hydrograph (GIUH) based approach, which uses the geomorphologic parameters, is used to simulate basin runoff. Compilation of the required database consists of various geomorphic and other hydrologic characteristics used by the GIUH model is facilitated using Geographical Information System (GIS). The main aim of this study is develop 1-Hr Unit Hydrograph (UH) from the GIUH using Linear Geomorphological Model (LGM) with the help of GIS. Valliyar is one of the sub basins of Kodaiyar River Basin in Tamil Nadu, India. Valliyar is 5th order stream. Sixteen possible paths are identified for stream order 5 and block diagram for each path is prepared. The overland region for each path is delineated and measured with the help of GIS. GIUH is developed for 15 minutes time step using probability density function. Lagging the GIUH, 1-Hr Unit Hydrograph (UH) is prepared.