1976-2017年柴达木盆地湖泊面积变化及其成因分析

Analysis on the variation and cause of the lake area in Qaidam Basin from 1976 to 2017

高原湖泊是反映气候变化敏感的指示器。利用1976-2017年的多源资料对柴达木盆地湖泊面积动态进行了监测。结果表明:近50多年来,柴达木盆地气候呈现气温升高,降水普遍增加的增暖增湿趋势,21世纪以来这一趋势更为明显,但存在地区差异,年平均气温升温速率自东向西趋于增加,降水增加速率自东向西趋于减小;柴达木盆地外围东部的托素湖面积1956-2017年总体呈弱的减小趋势,减速为0. 41 km^2·a^(-1)。但2005-2017年期间湖面以1. 34 km^2·a^(-1)的增速呈明显扩张趋势,中部的小柴旦湖面积与过去13年同期平均相比,扩大了19. 87 km^2,而西部的尕斯库勒湖呈先增加后减小的趋势。柴达木盆地气候变化、植被面积、入湖径流等因子是导致湖泊面积变化的主要原因。

The plateau lakes are sensitive indicators of climate change. The variation of lake area were monitored by using multi-source satellite data from 1976 to 2017 in the Qaidam Basin. The results show that the climate of the basin had been warming and humidifying in the 50 years, especially since 2000. The rising rate of annual average temperature had increased from east to west, and the increasing rate of precipitation had decreased from east to west. The Torsu Lake in the eastern part of the basin had less decreased from 1956 to 2017, with a rate of -0.41 km2·a^-1. However, during the period of 2005-2017, the lake surface had expanded at a rate of 1.34 km2·a^-1. The area of Xiaochaidan Lake in the basin middle had increased 19.87 km2 as compared with that in the past 13 years;while the area of the western Gaskule Lake had increased first and then decreased. Climate change, variations of vegetation area and lake runoff and human activity are the main causes of lake area change in Qaidam Basin.