Stable Channel Design of Tapi River Using HEC-RAS for Surat Region

Stable channel design plays an important role for the research of stream restoration. Since sediment transport rates are highly variable in observed stream, methods for channel design must study a wide range of transport relationships to define stability conditions. The objective of study is to design stable channel for the reach of the Tapi River located between Sardar Bridge and Magdalla Bridge using hydrodynamic software. Stable channel design has carried out using Copeland method which is a part of Army Corp of Engineer (HEC-RAS) software. In the present analysis, existing sections are compared with the design sections for 2006 flood having magnitude of 9.09 cusecs (25,760 cumecs). For study purpose, Tapi River reach is selected having 31 cross sections. The bed material samples from the study reach were collected and analyzed to determine the actual grain size. This paper presents a detailed design step of cross section using Copeland method including approximating the upstream channel as trapezoidal. Results indicate that the model adequately predicts the bank shape and significant dimensions of stable channels.