Assessment of Large River Basin Approaching GIS and Computation of Simulation Techniques Using Latest Software

Abstract

Advancements in computer techniques with a geographic information system (GIS) interface have greatly contributed to simulating river basins with a reasonable level of accuracy. It becomes possible to analyze and model various aspects of a river basin, such as water flow, land use, and hydrological processes. Water is essential for sustaining life. Previous studies revealed that effective watershed management requires an understanding of the impact of rainfall in the catchment area, but due to poorly gauged river basin, it becomes difficult to predict the hydrological response. In this context, hydrologic engineering centre – hydrologic modeling system (HEC-HMS) model is used to simulate surface runoff in different watersheds. The study simulated the Wainganga river basin, geographically located between longitude 78°0’–80°45’ E and latitudes 19°41’–22°50’ N. The model utilizes eighteen year data for rainfall extracted from Indian Meteorological Department with 0.25×0.25 grid. Similarly, evapotranspiration and observed discharge were extracted from India water resource information system. Shuttle radar topography mission dataset with digital elevation model of 30×30 m spatial resolution, extracted from United States of Geological Survey was an input to HEC-HMS 4.10. Different approaches with changing parameters were implemented for suitable simulation. SCS curve number method with Muskingum routing was implemented for study. The purpose of study was to compare the calculated and observed discharge as well as test model performance. Nash efficiency coefficients (NSE) were used for testing performance. The results show a satisfactory performance with NSE above 0.7 for basin. The description outlines, model can be used for assessing the behavior of large river basin.