Trends in runoff versus climate change in typical rivers in the arid region of northwest China

摘要

To clarify runoff and climate change trends and its relation in typical rivers in the arid region of northwest China (ANC), this study takes the runoff and meteorological data of 11 rivers in 5 typical river areas from mountain-pass as the research objects. The Mann-Kendall test, Extrapolation of Variance Analysis of Time-series Period and Correlation Analysis Method are applied to analyze the temporal and spatial variations of climate and runoff. The results show that in the past 50 years, the temperature, precipitation and runoff in the each river area exhibited an upward tendency. However, the runoff from the south slope of Altai Mountains and the north slope of Kunlun Mountains and the precipitation on the north slope of Qilian Mountains, the north slope of Kunlun Mountains and the south slope of Tianshan Mountains show inconspicuous changes. The increasing rates of temperature and precipitation in the river area of Northern Xinjiang is the largest, an average of 0.44 ℃/10a and 15.39 mm/10a; followed by that in the river area of Hexi Corridor, 0.29 ℃/10a and 7.64 mm/10a. The lowest one is in the river area of Southern Xinjiang, only 0.24 ℃/10a and 5.50 mm/10a. However, the increasing rate of runoff is the slowest in Northern Xinjiang while that in Southern Xinjiang is the fastest, mainly related to runoff recharge difference. The runoff recharge proportions from glaciers and precipitation have great effects on the relation between runoff and temperature and precipitation.