Emergency Control Scheme for Upstream Pools of Long‐Distance Canals

Abstract

AbstractAn emergency control scheme is proposed for pools upstream of a canal experiencing flow obstruction incidents. In order to achieve a prompt and efficient transition process, operation strategies are set out. It is suggested to switch from a constant downstream depth operation method to a constant volume operation method under qualified conditions. Based on a balanced pool operation equation and a transitional time estimation equation, a two‐step gate operation method is designed, which is compatible with the operation method of constant downstream depth and the mixed pool operation method of constant downstream depth and constant volume. The emergency control scheme is tested by simulations on the 561 km long Middle Route Project (MPR) of the South‐to‐North Water Diversion Project in China consisting of 30 pools. The constant downstream depth and mixed pool operation methods are examined. Results indicate that the control scheme operates well under the emergency situation of a flow obstruction incident. Canal flow moves promptly and effectively to the new steady state by switching to the constant volume method. Back and forth volume variation is avoided and a significant improvement is obtained in terms of transition time, while the times of check gate operation remain roughly the same. © 2018 John Wiley & Sons, Ltd.