2016年长江1号洪水过程中三峡水库防洪作用初步分析

Evaluations of flood control function of Three Gorges Dam on Yangtze River No.1 Flood in 2016

自2016年7月以来,长江上游及局部地区持续强降雨,造成湖北省武汉市大面积城市内涝,汉口水位超警戒水位,一些网站和民众对三峡工程的防洪作用产生怀疑。基于长江干流若干控制性水文站的实时水文数据,分析了2016年7月上旬长江洪水的时空演变过程,并与1998年同期洪水过程作了对比。研究表明:2016年7月上旬洪水流量和水位均超过1998年同期值,三峡水库若不拦截1号洪峰部分流量(最大达19 000 m3/s),将导致汉口站7月7日洪峰水位达29.72 m,三峡水库削减汉口洪峰水位1.35 m。三峡水库对长江中下游的防洪作用由此可见。

Starting from July 2016, strong rainfall has dropped in the upper reaches of Yangtze River that resulted in inundation of Wuhan City and high water level at Hankou that exceeded the warning stage. Doubts have been emerged about the role of Three Gorges Dam on flood control by some websites and general public. According to real-time hydrological data of some control stations on the mainstream of Yangtze River, spatial-temporal evolution of flood in early July is analyzed and compared with the flooding in the same period in 1998. The result shows that flood discharge and water level in 2016 are much higher than that in 1998. The maximum flood peak of No.1 flood in 2016 reached as high as 19 000 m3/s, which may heighten the water level at Hankou Station to 29.72m on the 7th of July without Three Gorges Dam. That means Three Gorges Dam helped to reduce flood peak by 1.35 m at the Hankou Station which eliminate risk of flooding in the middle and lower reaches of the Yangtze River.