基于入库洪水识别模型的洪水资源利用潜力评估

Evaluation of flood resource utilization potential based on identification model for inflow flood

洪水资源利用潜力评估是合理调配流域水资源与储水空间的前提。针对我国水资源时空分布不均问题,基于Kolmogorov-Smirnov检验、改进超定量法与带时畸参数的泊松标值过程模型,构建入库洪水识别模型,实现非一致性径流时间序列向“独立同分布”样本的转化,识别与推求入库洪水代表性线型;综合流域调蓄能力与用水需求等约束,提出水库群洪水资源利用潜力评估方法,定位关键制约因素,界定预留防洪库容与水位上浮空间均衡防洪与兴利功能。以金沙江下游乌东德、白鹤滩、向家坝与溪洛渡四座水库(金下四库)为研究对象,结果表明:1998与2002年为向家坝水文站6-11月序列一致性变更点;入库洪水以矮胖型为主,3日洪量是比洪峰更应优先考虑的联合调度决策特征参数;受限于储水空间,遭遇百年一遇及以下设计标准洪水,金下四库洪水资源利用潜力为37.27亿m^(3),为持续优化调蓄空间,建议依次上浮运行水位至952.26、806.77、576.31与373.99 m。研究成果以期为变化环境流域水资源与储水空间优化配置提供参考。

Evaluation of flood resource utilization potential is a prerequisite for the rational allocation of water resources and storage capacity in a watershed.In response to the problem of uneven spatiotemporal distribution of water resources in China,an inflow flood identification model was established based on the Kolmogorov-Smirnov test,improved peak-over threshold method,and time-varying parameters with Poisson distribution model.It aims to achieve the transformation of inconsistency runoff time series to“independent identical distribution”samples,and to identify and deduce representative flood hydrograph of inflow flood.An evaluation method of flood resources utilization potential in reservoir groups was proposed based on constraints such as the comprehensive regulation and storage capacity of the watershed and water demand.It aims to identify key constraints,define reserved flood control storage capacity and water level floating space to balance flood control and benefit functions.The Jinxia Four Reservoirs,which consist of Wudongde,Baihetan,Xiangjiaba,and Xiluodu cascaded reservoirs in the lower Jinsha River,were used as a case study.The results show that 1998 and 2002 are the consistency change points of the runoff series from June to November at Xiangjiaba Hydrological Station.The main type of inflow flood is short-fat,and the 3-day flood volume is a joint operation decision characteristic parameter that should be given more priority than the flood peak.Jinxia Four Reservoirs are constrained by storage capacity,when encountering floods with a design standard of once-in-a-century or below,the utilization potential of flood resources is 3.727 billion cubic meters.It is recommended to continuously optimize the storage capacity by raising the water level to 952.26 m,806.77 m,576.31 m,and 373.99 m in sequence of Jinxia Four Reservoirs.This work aims to provide reference for the optimal allocation of water resources and storage capacity in the watershed.