Climate change of the Yangtze River basin and impacts on flow discharge

Yan-shu Rong, Jia Wei, Ya-nan Xu, Wen Wang

Thursday 2 july 2015

12:42 - 12:45h at Central America (level 0)

Themes: (T) Water resources and hydro informatics (WRHI), (ST) Catchment hydrology, Poster pitches

Parallel session: Poster pitches: 11H. WRHI - Catchment

The Yangtze River is the biggest river in the China and the Asia, accounting for 18.8 % in the total land areas and 38.0 % in the water resources for China. In the recent 50 years, the climate of the Yangtze River basin has obviously changed duo to building a larger number of key water conservancy projects, and brings about great effects on the water cycle, environment and ecosystem of this basin. In this article, the data of key climate elements for 50 years (1961-2010) were used to analyze the climate changes in this basin, including air temperature, precipitation, wind speed, relative humidity and sunshine duration, coming from 138 meteorological sites. As one of the component of water cycle, the flow discharge time series was analyzed and the impacts of the climate change were investigated on the flow discharge of the lower reaches of the Yangtze River by means of series analysis, M-K non-parameter test, relationship analysis, and composite analysis. The results showed that the significant changes of the climate took place in the Yangtze River basin, especially after 1990. It was characterized by the rising air temperature, but the decreasing precipitation, relative humidity, and sunshine duration, and this kind of behavior of the climate clearly decreases the flow discharge in lower reaches of the Yangtze River. It is the major factors that precipitation, relative humidity, and sunshine duration resulted in the decrease of the flow discharge in the lower reaches, but not air temperature and wind speed. The decrease of flow discharge will not only weaken speed of water cycle but also result in press of rising water demands. This is a dangerous signal!