Synthetic unit hydrograph for ungauged basin using Synder, Taylor- Schwarz model, SCS method by GIS techniques

Abstract

In hydrology, estimation of the design hydrograph (DH) is a crucial challenge because of lack of rainfall- runoff data. The lack of rainfall-runoff data makes developing credible DHs particularly difficult in small and ungauged basins. A synthetic unit hydrograph(SUH) is a way to represent the flow of water in a stream or river as a single point. It is used to calculate runoff and other hydraulic functions by using watershed characteristics for similar watershed. On the basis of watershed and watershed features or characteristics, equations for estimate of synthetic unit-hydrograph parameters based on rainfall and runoff data for small watersheds were developed. Estimating runoff is a crucial part of river basin planning, development, and management. This paper discusses the application of synthetic unit hydrographs in the Dhamani drainage basin in Maharashtra, India. Traditional method of SUH are used to calculate the peak discharge and time to peak. The calculated discharge by using Synder method, Taylor- Schwarz model, SCS method were compared with each other. In a drainage basin, the relative mean error (RME) and the root of mean square error (RMSE) were compared for selection of better option or to find minimum error method.