A Numerical Method for Cross-Section Changes and Gates Resulting from the Riemann Problem in Irrigation Canal Systems

Abstract

Hydraulic simulation models offer unlimited opportunities for improving the performance of irrigation canal systems by studying the flow behavior in a large and complex canal network under a variety of design and management scenarios. This paper presents an inner boundary in the junction-point water stage prediction and correction method, which deals with abrupt section change and the gates. To reduce the number of global iterations in the correction step, an acceleration method for local updates is also proposed. The results show that the proposed inner boundary satisfies the C Property and consistency, which can deal with hydrostatic conditions and dam-break junctions. The simulations in the test canal system show that the proposed inner boundary can simulate the control gate action and the resulting hydraulic response process in each pool. The proposed acceleration method can effectively reduce the number of global iterations, but the acceleration effect can only be improved by about two times.