ABSTRACT
Stable channel design is a term aimed at minimizing flooding and sedimentation-induced river channel deformation. River flooding is the most common type of flooding in many parts of the world. The Army Corps of Engineers’ Hydraulic Engineering Center River Analysis System now includes the Copeland method approach for analyzing geomorphologically stable channels. Stream reconstruction research focuses on stable channel design. Since measured stream sediment transport rates are highly complex, channel design approaches should consider a wide range of transport relationships to determine stable conditions. This chapter presents the design for physical enhancement of the reach of the Tapi River located between Sardar Bridge and Magdalla Bridge using hydraulic design function HEC-RAS 6.0.0. In the present analysis, the existing sections are compared with the design sections for the 1968 flood having a magnitude of 43,924 cumecs. The study reach consists of 31 cross-sections. To assess the actual grain size, bed content samples from the Tapi River were collected and analyzed. This chapter shows how to plan a cross-section step by step using the Copeland method which includes the approximation of the upstream channel as trapezoidal. The results indicate that the model accurately evaluates the shape of the bank and the dimensions of the stable channels.
