全球气候变化对泾河流域径流和输沙量的潜在影响

 全球气候变化对水循环产生巨大影响,而降水特征的变化因区域的不同有较大差异,这些变化对河流径流、泥沙及区域水土流失具有重要影响。以1961—2006年泾河流域降水、径流和输沙量等资料为基础,建立降水和径流、径流和输沙量之间的统计关系。通过5个大气环流模式(HadCM3、CGCM2、CSIRO-Mk2、ECHAM4和GFDL)对泾河流域未来不同时期(2010—2039年、2040—2069年和2070—2099年)的降水量进行模拟,进而根据统计关系计算出未来不同时期该流域的径流、输沙量。结果表明:不同大气环流模式对该流域降水量模拟结果不同,导致未来气候条件下径流和输沙量的预测也存在一定差异。比较IPCC排放情景中的A2、B2气候情景发现,在A2情景下径流和输沙量响应更为强烈。与近期实测资料(1961—2006年)相比,未来(2010—2099年)泾河流域降水、径流和输沙量的变化范围分别为-5.53%～31.65%、-9.26%～53.44%和-11.13%～64.59%,平均增加11.69%、19.78%和23.94%。研究结果对未来黄土高原水土保持规划和治理策略的制订具有指导意义。

Response of runoff and sediment discharge to global climate change in Jinghe River Basin

Global climate change had a tremendous impact on the water cycle. Changes in precipitation features varied from region to region, and they also impact on river runoff, sediment discharge and regional soil loss significantly. Based on the data of precipitation, runoff and sediment discharge from 1961 to 2006 in Jinghe River Basin, this study analyzed the statistical relation between precipitation and runoff, and between runoff and sediment discharge. According to the results of precipitation of three periods （2010-2039, 2040-2069 and 2070-2099 ） which simulated by five GCMs （HadCM3, CGCM2,CSIRO-Mk2, ECHAM4 and GFDL） , the statistical relations to calculate runoff and sediment discharge in the future was brought. The results showed the ability of simulated data varied by different GCMs. It led to the difference of estimated runoff depth and sediment discharge. Compared of A2 and B2 scenarios published by IPCC, it indicated that the response of runoff and sediment discharge under A2 scenario was more strongly. And contrasted to the measured period （1961-2006） , the variable ranges of precipitation, runoff depth and sediment discharge from 2010 to 2099 were - 5.53% - 31.65% , -9.26% -53.44%, - 11.13% -64.59% respectively, and the average increases were 11.69%, 19.78% and 23.94%. The finding of this study played guiding significance to the planning of soil and water conservation and strategy establishment in the future of the Loess Plateau.