北江乐昌峡水库流域汛期分期研究

Identification of Flood Seasonality for the Lechang Gorge Reservoir Basin

摘要: 北江是珠江流域第二大水系，近年来流域洪水灾害频发，对当地居民生命和财产安全造成了严重威胁，因此其上游防洪体系建设对流域防洪至关重要。乐昌峡水利水电枢纽是北江上游防洪控制性工程，承担着下游韶关市和乐昌市等地的防洪任务。目前水库采用固定汛限水位法进行调度，无法充分发挥枢纽效益，根据汛期水文规律合理地进行汛期分期能够显著提升枢纽的防洪效益和发电效益。本文在讨论各分期方法的优缺点的基础上，综合运用水文特征值法、矢量统计法、模糊分析法、有序聚类法等计算乐昌峡水库流域汛期分期方案，发现乐昌峡水库在5月初至7月初洪水发生频率和量级都比较大，并最终得到分期结果为前汛期3月1日至4月20日；主汛期4月21日至7月10日；后汛期7月11日至9月30日。

Abstract: The North River is the second largest drainage system of the Pearl River basin, and recently it has been suffering floods, which is a serious threat to public safety and property. Therefore, the con-struction of its upper reaches flood control system is of great significance. The Lechang Gorge Re-servoir is main part of the upper reaches flood control system of the North River, which protects the security of Shaoguan and Lechang Cities in downstream area. At present, the reservoir uses static flood limited level for operation, which can’t make full use of resources sufficiently. Reasonable identification of flood seasonality for the Lechang Gorge will promote the benefits of flood control and power generation. Based on discussing the advantages and disadvantages of each method and utilizing hydrological characteristic analysis method, vector statistic method, fuzzy analysis method and orderly cluster method, it was found that both the flood frequency and magnitude were large between early May and early July, and finally flood seasonality for the Lechang Gorge Reservoir was identified as three parts, namely pre-rainy flood season (March 1st-April 20th), major flood season (April 21st-July 10th) and after-rainy flood season (July 11th-September 30st).