Risk analysis of reservoir level during rehabilitation

Abstract

After five decades of service since 1953, the storage capacity of Ah-gong-dein reservoir in Taiwan has been reduced by about 71% due to accumulated sedimentation. Its ability to serve flood control function has been greatly compromised. The Taiwan Department of Water Resources currently is undertaking measures to vitalize its flood control function over an eight-year period. The paper addresses probabilistic behavior of reservoir surface level during the rehabilitation period. In particular, randomness of monthly rainfall amounts is considered in developing function relationship between monthly probability of water surface elevation exceeding certain target level and various factors. Information such as these is useful to examine the implications of proposed rehabilitation schemes on overtopping risk and to monitor the required revitalization progress and reservoir storage condition.