Geomorphological Instantaneous Unit Hydrograph (GIUH) for an Ungauged Watershed

Abstract

In the present micro climate change conditions, there is a need for managing the available water resources and their optimum utilization for various purposes. This work aims at developing the Geomorphological Instantaneous Unit Hydrograph (GIUH) by using rainfall-runoff characteristics of an unguaged basin. The rainfall-runoff relationship can be developed using different empirical and conceptual methods. The empirical models are site specific. One has to develop separately for each basin. But earlier models were developed with few fixed parameters applicable to all the basins. A conceptual model developed by Rodriguez-Iturbe and Valdes relates the peak runoff and time to reach peak (unit hydrograph parameters) with the Geomorphological parameters of the basin. Remote sensing images and Survey of India toposheets are used to calculate these parameters in the present study. Basin parameters can be modified considering user needs with the help of GIS software. The study area chosen is the Khanapur watershed which is an unguaged lying in the mid Godavari basin. GIS database is developed using the basin parameters namely, drainage network map, slope map, land use / land cover map, and contour map in the analysis to find the Nash GIUH model parameters.