Identification of Risks and Estimation of Flood Storage in Ponds

The article demonstrates methods for identification and assessment of risks for efficient utilization and storage of floodwater, which can be utilized in middle and lower reaches of rivers. Firstly, the methods of analytic hierarchy process and principal component analysis were proposed, which can identify the main risk factors and associated losses during the storage of floodwater in ponds. The major factors of risk include uncertainty of benefit losses, uncertainty of calculation methods and parameters, long-term rainfall-runoff forecasting errors, scheduling decision, and implementation. Next, a two-dimensional estimation model used to get the risk rate of flood storage in ponds during different stages of flood including scenarios with and without control measures is developed. The identified risk factors were applied on an event of rainfall (200 mm) to evaluate the risk of flood storage in Cile pond. To conclude, the laws of risk in terms of space and time are demonstrated as follows: (1) in spatial dimension, the risk involved will be higher if flood storage capacity is great, and, (2) in temporal dimension, the risk involved will be higher if storage occurred earlier than anticipated. This article further concludes that if flood storage is greater, the risk loss associated with control measures will obviously be smaller than that without control measures.