从干支流洪水能级的跃迁透视人类活动影响的利弊

Impact of Human Activity on Transition of Flood Energy Level of the Main Stem and Tributaries

通过6个洪水指标因子融合了洪水具有时域性和动态性的特征,提出了洪水能级的概念,并建立了模拟退火算法的模糊K-means聚类模型,以它为确定洪水能级的背景模型来量化洪水能级,根据最优目标函数,确定最佳洪水能级的级别数。在此基础上,以北江流域为例,建立了径向辐合型洪水能级跃迁图,从全新的角度论述人类活动影响的利弊。研究结果表明:强干控支措施的实施及水利工程的建立,实现了各支流洪水能级输出的转变,改善了流域的防御性能,由"开放"型转变为防洪能力较强的"防御"型流域,大大降低了干流洪水能级径内跃迁的可能性。科学合理的人类活动有利于干支流洪水能级的削弱,缓解干支流的防洪压力。同时,本研究提出的洪水能级概念及其计算模型具有可拓性,为洪水的分类、频率的计算、洪灾的评估等工作提供了新的起点和思路。

Based on six flood indexes, presenting time domain and dynamic characteristic, a concept of the flood energy level is proposed in this paper. The fuzzy k-means cluster model with simulation annea- ling algorithm is used to calculate the flood energy level. The value of flood energy level is obtaind from the most superior objective function. The Beijiang catchment is taken as a case study. The results show that the hydraulic engineering can improve the basin defense performance, which has transferred from an open to a defense basin, with reducing possibility of the flood energy level diameter jumps. The reasona- ble human activities can weaken the branch flood energy level and alleviate the flood prevention pressure. The concept of flood energy level and its computation model have provided new methods for flood classification, frequency computation and flood disaster appraisal and can be applied in other domains.