气候变化对长江、黄河源区水资源的影响

利用1961—2010年长江、黄河源区22个气象站的月降水量和月平均气温资料,分析长江、黄河源区的气候特征,用降水与蒸发的差值作为水资源量的代表,分析了气候变化对水资源的影响。结果表明,长江源区和黄河源区降水、气温和蒸发都有明显变化,尤其是近20年有明显增加趋势,但是两个源区的变化并不一致,黄河源区水资源量一直呈波动变化,而长江源区在最近10多年水资源量有明显增多现象。降水增多可直接增加水资源量,但是气温升高会促进蒸发,导致更多的水资源消耗,因此降水和气温的变化可相互抵消对水资源的影响,这是黄河源区水资源量变化不大的原因。但是近10多年长江源区气温显著增加,导致更多冰川融化,这可能是近年来长江源水资源量增多的原因。

Impacts of climate change on water resources in source regions of Yangtze River and Yellow River

The characteristics of the climate in the source regions of the Yangtze River and Yellow River were analyzed based on the monthly precipitation and monthly mean temperature at 22 meteorological stations from 1961 to 2010. The difference in the value between precipitation and evaporation was used to represent the water resources, in order to analyze the impacts of climate change on the water resources. The results show that the precipitation, temperature, and evaporation in the source regions of the Yangtze River and Yellow River have changed significantly, especially in the last 20 years, when there were significant increasing trends in these properties. The water resources presented a fluctuating variation in the source region of the Yellow River and increased significantly in the last 10 years in the source region of the Yangtze River. The increase of precipitation can directly lead to the increase of water resources; however, the increasing temperature can lead to high evaporation that would consume more water resources. Therefore, the influences on water resources can be balanced out by the changes of precipitation and temperature, which explains why there is no significant change in the water resources in the source region of the Yellow River. The temperature increased significantly in the last 10 years in the source region of the Yangtze River, causing more glaciers to melt and water resources to increase in the region.