1958~2015年疏勒河上游出山径流变化及其气候因素分析

利用1958~2015年疏勒河出山口昌马堡水文站径流资料以及同期流域气象资料,揭示了疏勒河出山径流及其对流域气候变化的响应。结果表明：总体上,疏勒河出山径流量呈现增加趋势,特别是20世纪90年代后期以来,出山径流增加趋势更为明显,但近几年,疏勒河出山径流量缓慢回落,21世纪初暂时成为代际变化的拐点。研究亦显示,疏勒河出山径流对河源处高海拔山区气候变化的响应更为敏感,出山径流年际变化实际受到山区气候因素的共同影响,不同时段各因素影响强度具有一定差异;降水是出山径流变化的主控因素,但气温升高导致冰雪融化加快是近年来出山径流增长较快的重要原因。定量分析表明,20世纪90年代后期以来气温等对径流影响比重超过60%,而降水约为30%左右。

Mountainous Runoff Changes and Climate Factors Analysis of the Shule River Basin in 1958-2015

Mountainous runoff is very important to the inland river basin in Northwest China, because it is related to the oasis ecological environment security and the social and economic sustainable development in the middle and lower reaches of the basin. Therefore, more and more studies are focused on the changes of mountainous runoff under the climate change in this region. The Shule River is one of the three largest inland river in Hexi Corridor, Gansu Province, Northwest China. Based on the runoff data at Changmabu hydrological station and the meteorological data of the Shule River Basin during the period 1958-2015, this article analyzed the characteristics of mountainous runoff of the Shule River Basin and its response to the climate change. The trend of mountainous runoff is analyzed by the line trend method. The mutation of mountainous runoff is analyzed by the Cumulative departure method. Morerover, the evapotranspiration is calculated by the Takahashi formula, and the relationships between mountainous runoff and climate factors are analyzed by the Correlation and Sliding correlation method. The main results were obtained as follows: In general, the mountainous runoff of the Shule River Basin presents an increasing trend in the research periods, and this trend was more obvious since the late 1990s, however, it is declined slowly in recent years. Moreover, the runoff series appears an obvious mutation in 1997. Finally, the correlation analysis shows that precipitation was the main control factor for the mountainous runoff changes. At the same time, the increased snow and ice melt caused by the rising temperature was the main reason for the changes of mountainous run off in recent years. In a word, the variability of runoff depends on the comprehensive impact of the climate factors for the effect of each factor is inconsistent in different stage.