帕米尔高原东部径流量变化及其对气候变化的响应

水资源是制约中国西北干旱区社会经济可持续发展和生态安全的关键因素。以发源于帕米尔高原东部的喀什噶尔河和叶尔羌河流域为研究区,基于该区6个气象站月平均气温和降水量观测资料,以及5条代表性河流的出山口水文站1950年代晚期以来的月径流量观测数据,分析了该区域气候和水文年际变化特征,以及气候变化背景下径流量的响应特征。结果发现：(1)研究区降水、气温都呈显著上升趋势,除盖孜河外,所有河流径流量均呈显著上升趋势。河流径流量的年内分布和年际变化特征反映了各河流径流主要补给来源的差异。(2)帕米尔高原东部河流出山口径流量受到气温和降水的共同影响,其中以冰川补给为主的叶尔羌河、库山河和盖孜河年径流量与当年夏季（6—8月）气温显著正相关（P<0.001);以降水和积雪补给为主的提孜那甫河和克孜河年径流量与上年7月至当年6月降水量显著正相关（P<0.001)。(3)随着气温升高和降水量增加,流域的蒸发加剧,帕米尔高原东部河流径流量对气候变化的响应出现了明显的变化：年径流量与夏季气温的正相关关系减弱,与上年7月至当年6月降水量正相关增强。

Streamflow variation in the eastern Pamirs and its response to climate change

Water resources were the vital factors restricting the sustainable development of social economy and ecological security in the arid region of Northwest China. The Kashgar River and Yarkant River Basins, which originated in the eastern Pamirs, were taken as the study area. Based on the monthly temperature and precipitation data from six meteorological stations and monthly streamflow data from the mountain-pass hydrological stations of the five representative rivers in the eastern Pamirs, the hydroclimate change characteristics and the response of streamflow to changing climate were analyzed. The results are as follow. (1) The precipitation and temperature both showed a significant increasing trend. Except for the Gaizi River, streamflow of all other four rivers showed a significant increasing linear trend. The intra-annual distribution and inter-annual change characteristics of streamflow from different rivers reflected the differences in the main recharge sources. (2) The streamflow in the eastern Pamirs was affected by the combined effects of temperature and precipitation. Annual streamflow dominated by glacier meltwater (the Yarkant River, Kashgar River, and Gaizi River) was mainly affected by summer temperature, and it was significantly positive correlated with the temperature from June to August. While, the streamflow dominated by rainfall and seasonal snow meltwater (the Tizinafu River and Kezi River) was significantly positive correlated with the precipitation from July of the previous year to June at the 0.001 significance level. (3) With the increasing temperature and precipitation, the evaporation of the watershed intensified, and the response of streamflow in the eastern Pamirs to climate change had changed significantly: the positive correlation between streamflow and temperature weakened, and the positive correlation between streamflow and precipitation from previous July to June strengthened.