摘要
大型水利水电工程的运行会改变天然河道径流机制,影响下游流域的水资源分配、防洪和水生态安全。本研究基于典型水文站长期径流观测资料和中国地面降水格点数据集,系统分析了三峡水库运行对长江中下游流域水文机制的影响。结果表明:(1)三峡水库运行后中下游典型水文站流量过程线有所坦化,低值流量出现的概率增加而高值流量出现的概率有所降低;(2)水库运行后,长江中下游典型水文站的月流量变化与水库的季节性调蓄密切相关,枯季径流量增加而蓄水期径流量有所减少;(3)三峡水库运行能减少枯季流量出现的频次且增加枯季流量历时,使得最小流量出现的时间有所推后。水库的调蓄作用使洪水季和枯季径流量的波动性减弱,并且其对下游水文机制的影响沿大坝自上而下逐渐减弱。三峡大坝对水文机制的改变会对长江中下游水生生物栖息环境和生活史产生影响,需设计合理的水库生态调度方案,消除三峡水库带来的不利影响,保障长江流域防洪、生态、水资源安全和社会经济可持续发展。
The construction and operation of large hydroelectric project can alter natural flow mechanism, andfurther impact the spatial-temporal distribution of water resources, flood prevention and water ecological securityin the lower reach of a river. This study analyzes the influences of the Three Gorges Dam on the hydrologicalmechanism in the middle and lower reaches of the Yangtze River based on long-term daily stream flow and pre.cipitation observations. The results show that： （1） The hydrographs at the representative hydrological stations inthe middle and lower reaches of the Yangtze River become flat with the occurrence probability of high flow （lowflow） decreaseing （increasing） after the run of the Three Gorges Dam; （2） The changes of monthly stream flow inthe middle and lower reaches of the Yangtze River are closely related to the seasonal reservoir operation of the Three Gorges Dam. The stream flow increases in low-flow seasons but decreases in impoundment periods; （3） Af？ter the run of the Three Gorges Dam, the stream flow decreases in impoundment periods and post-flood seasonsbut increases in low-flow periods. Moreover, the low flow spell count and the stream flow variability in bothflood seasons and non-flood seasons decline while the low flow spell duration increases. The Julian date of theannual minimum daily runoff is postponed correspondingly. The impact of the Three Gorges Dam on flow re？gimes weakens gradually from the dam to the estuary of the Yangtze River. The induced changes in flow regimeswould further impact the habitat and life history of aquatic biota in the middle and lower reaches of the YangtzeRiver. More reasonable and ecology-oriented reservoir operation rules are recommended to eliminate the poten？tial negative effects of the Three Gorges Dam, and to ensure the securities of water resources, flood preventionand ecology as well as the sustainable socioeconomic development of the Yangtze River.
作者
刘文彬
杨涛
杜牧野
孙福宝
刘昌明
LIU Wenbin;YANG Tao;DU Muye;SUN Fubao;LIU Changming(Key Laboratory of Water Cycle and Related Land Surface Processes,Institute of Geographic Science and Natural Resources Re？search,Chinese Academy of Sciences,Beijing 100101,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《三峡生态环境监测》
2018年第3期8-15,共8页
Ecology and Environmental Monitoring of Three Gorges
基金
中国科学院重点部署项目(ZDRW-ZS-2017-3-1)
关键词
三峡水库
水文机制
年内变化
累积概率曲线
长江流域
Three Gorges Dam
hydrological mechanism
intra-annual variability
cumulative probability curve
the Yangtze River basin
