Assessment of hydraulic performance changes of Dongting Lake after the Three Gorges Reservoir impoundment by a novel semi-empirical approach  

基于一种新的半经验方法评估三峡水库运行后洞庭湖水力特性变化

作　　者：SUN Zhaohua LI Zhiqing CHEN Li FAN Jiewei LIU Ya 孙昭华;李芷晴;陈立;范杰玮;刘亚

机构地区：[1]State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China [2]Yellow River Water&Hydropower Development Group Co.,Ltd.,Jiyuan 459017,Henan,China [3]Changjiang River Scientific Research Institute,Wuhan 430010,China

出　　处：《Journal of Geographical Sciences》2024年第8期1537-1557,共21页地理学报（英文版）

基　　金：National Natural Science Foundation of China,No.51879198;The Follow-up Research Program for the Three Gorges Project from the Ministry of Water Resources of China,No.12630100100020J005。

摘　　要：Floodplain lakes are important water storage areas in lowland regions that often undergo geomorphologic evolution,and timely topographic data are generally unavailable.In this study,to assess the impacts of lakebed deformation on hydraulic performance in Dongting Lake,a set of semi-empirical methods was proposed to establish performance graphs(PGs)using only hydrological data.These methods were used to evaluate the changes in water level,storage capacity,and flood detention ability in Dongting Lake caused by topographic adjustment after the Three Gorges Reservoir impoundment.These methods showed that PGs can effectively simulate the water level and outflow processes of Dongting Lake with Nash-Sutcliffe efficiency coefficients(NSEs)above 0.9.A comparison of the estimated water level and discharge using PGs from different periods suggested that bed erosion in Dongting Lake caused water level decreases of 0.18 m and 0.32 m during the flood and dry seasons,respectively.Because the magnitude of erosion at high elevations in the lake is small,the impacts of bed adjustment on the storage capacity and flood detention ability are not currently significant.This study showed that the hydraulic performance of a floodplain lake can be evaluated independently of topographic data under the condition of no reverse flows or negative watersurface slopes.

关 键 词：Dongting Lake hydraulic performance graph bed adjustment semi-empirical approach backwater effect 

分 类 号：TV61[水利工程—水利水电工程] TV131