The prerelease operational policy of reservoir for flood control based on ensemble streamflow prediction

• Main Authors: Yi-Ling Huang, 黃怡綾
• Other Authors: Jiing-Yun You
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/03935470752365611900

碩士 === 國立臺灣大學 === 土木工程學研究所 === 102 === Traditional flood control operation of reservoir during flooding season is water level-based strategy. This kind of water level-based strategy is governed on reservoir regulation schedule determining the tradeoff between flood control and conservation. Currently, reservoir operation faces new challenges resulting from the impact of climate change. In recent decades, it has caused an increase in the frequency and severity of extreme weather events globally. The water level-based strategy has less flexibility and might cause problems. On the basis of real-time rainfall/inflow prediction, dynamic control of reservoir implies that the water level need to control based on updated information, also requires more comprehensive analysis with respect to different purposes. The main objective of this study to develop the prerelease operation policy of reservoir for flood control based on ensemble streamflow prediction. With advanced meteorological and remote-sensing technologies, rainfall and streamflow prediction several hours ahead can be achieved in an ensemble and probabilistic format. With the help of stochastic prediction, this study aims to develop an operational strategy mitigating flood control threats without increasing the water shortage risk. The operational policy need to balance the tradeoff between ‘gaining more flood buffer for dam security paying the expense of increasing shortage risk’ or ‘ensuring adequate water resources by enduring the potential of flooding damage’. A simple idea of that if release error occurred due to inflow forecast, then the next time the operator should retrieve the error by reducing release. For this concern, this study proposes a prerelease operational rule for flood control, and further examine the possible risks both of that the target release should be increased and the reservoir cannot be filled after the storm. In the end, this study investigates the efficiency of the operational strategy of Shihmen Reservoir with Typhoon Jangmi and Tsengwen Reservoir with Typhoon Morakot as case studies.