Risk Analysis of Spilling Water for Long-Term Optimal Operation of Cascade Hydropower Plants

摘要

The phenomena of spilling water is an increasingly serious issue of reservoir operation in southwest China, such as Wujiang River Basin facing the risk of spilling water in long-term operation because of unpredictable characters of stream inflow. The risk is originally measured by two aspects-the probability of the event and the seriousness of the consequences, and only the probability is taken into account in this study. This paper established a practical method to measure spilling water probability. First, this study using spilling water ratio to describe spilling water probability. Second, a reduction method based on the constant of total amount of inflow is provided to simulate many stream inflow processes corresponding to one certain stream inflow scenario. At last, the number of processes encountered spilling water can be count through long-term optimal operation of reservoir. As a result, a risk analysis method is set up to quantify the spilling water risk by defining the ratio of the number of failure processes (encounter spilling water) to the total processes number. Case study indicated that this method can effectively describe the risk of spilling water and provide guidance for reservoir operation.