汉江上游流域水文循环过程对气候变化的响应

The Response of the Upstream Hydrological Cycle Process to Climate Change in the Upper Hanjiang River Basin

气候变化对水资源的时空格局及水循环产生了不同程度的影响。以汉江上游流域为例,采用线性回归法、Mann-Kendall非参数检验等方法,分析了1961-2013年的水文气象要素变化特征;构建了分布式时变增益模型(DTVGM),验证了模型在该流域的适用性;根据CMIP5多模式集合平均的结果,分析了RCP4.5和RCP8.5情景下2011-2099年的降水、气温及径流的响应过程。结果表明,1961-2013年汉江上游流域年降水量随时间缓慢减少,气温显著上升,年均径流量显著减少;在两种气候情景下,未来该流域降水量较基准期有所增加,气温随时间将显著上升,径流量较基准期减少但是随时间呈现增加趋势。结果预示着在未来气候变化的情况下,汉江上游流域水文循环将受到较大影响,可能出现一定程度的水资源短缺。

Climate change has different degrees of impact on the spatial and temporal patterns of water resources and the water cycle. Taking the Upper Hanjiang River Basin as an example, this paper analyzes the variation characteristics of hydrometeorological elements from 1961 to 2013 by linear regression method and Mann-Kendall nonparametric test. The Distributed Time Variant Gain Model (DTVGM) is constructed, and the applicability of this model in the basin is verified. According to the results of CMIP5 multi-mode set average, the change of precipitation, temperature and the runoff response process in 2011-2099 under RCP4.5 and RCP8.5 is analyzed. The results show that, from 1961 to 2013, the annual precipitation in the Upper Hanjiang River basin gradually decreased with time, the temperature increased significantly with time, and the annual average runoff decreased significantly with time. Under the two climatic scenarios, the precipitation in the Upper Hanjiang River Basin will increase in the future compared with the baseline period, the temperature will increase significantly with time, and the runoff will decrease from the baseline period but will increase with time. The results indicate that in the future climate change, the hydrological cycle in the Upper Hanjiang River Basin will be greatly affected, and there may be a certain degree of water shortage.