摘要
干旱区湖泊是区域水资源系统的重要组成部分,不仅在维系区域生态系统平衡上发挥重要支撑作用,而且也对区域气候变化和人类活动具有重要的指示意义。基于Google Earth Engine(GEE)遥感云计算平台,以Landsat 5/7/8卫星遥感影像为主要数据源,分析了1986—2019年新疆维吾尔自治区湖泊数量以及面积变化的时空特征,并从气候要素变化、人类活动干扰等方面初步探讨了新疆湖泊变化的主要原因。结果表明:1986—2019年间,气温升高使得冰川积雪融水增加,新疆湖泊整体上呈现出扩张趋势。然而受人类活动的干扰程度以及地形海拔等因素,这种趋势存在显著的空间差异。全球变暖背景下,由于受到丰富稳定的雪冰融水的补给,受人为干扰较小的青藏高原北部地区湖泊呈现显著扩张。相反由于环天山地区强烈的人类活动以及冰川加速退缩影响,该区域湖泊面积持续高位波动状态。
Lake is one of the important surface water resources in arid regions. They not only play an important role in maintaining the regional ecosystem balance, but also as a sensitive indicator of climate and environmental changes. Mapping and monitoring the lake area changes are essential to formulate the regulation policy on local water resources utilization. According to the second National Lake Survey(2007—2011), there are 108 lakes(more than 1 km^(2)) in Xinjiang Uygur Autonomous Region. Compared with the first National Lake Survey(1960 s—1980 s), there are 62 Lakes(more than 1 km^(2)) disappeared in Xinjiang, which accounting for 87% of the total area of disappeared lakes in China. Disappeared lakes are the main sources of saline dust storm which become a serious threat to regional ecological security and human health. Spectral indices method was mostly conceived for water body identification on imagery from medium resolution, broad-band multispectral sensors like Thematic Mapper(TM), Enhanced Thematic Mapper Plus(ETM+), SPOT-5, etc. Thus, this study proposed a water body extraction method based on dynamic threshold of multiple remote sensing spectral indices. Based on the remote sensing cloud computing platform-Google Earth Engine(GEE), this study has analyzed the spatio-temporal characteristics of the lake numbers and areas in Xinjiang from 1986 to 2019 based on Landsat images. The main reasons for the lake changes were preliminarily discussed in aspects such as climate change and human activities. The results were as follows: 1) The water body extraction method based on multiple spectral indices proposed in this study has a better identification result in different types of lakes in arid region. 2) The number of lakes in Xinjiang(more than 0.5 km;) has been increasing overall since 1986. Especially in the past 10 years, the lake number has shown a sharp increase, mainly in the area around Tianshan Mountains. And in the northern part of the Qinghai-Tibet Plateau, the number of lakes(less than 5 km;) has increased significantly. 3) During the study period, the area of main lakes(more than 10 km;) showed a significant expansion trend, and lakes with significant expansion were mainly concentrated in the northern part of the Qinghai-Tibet Plateau. Ayakum Lake had the most significant expansion trend(+16.52 km;/a., P<0.01) in the study area. However, lakes around Tianshan Mountains have a frequent inter-annual fluctuation in recent years. 4) Under the background of global warming, plateau lakes continued to expand steadily after 1997 due to the supply of abundant snow and ice melt water and minor human disturbances. On the contrary, the lakes around the Tianshan Mountain were simultaneously affected by accelerated retreat of glaciers and human activities. Therefore, the lakes have been fluctuating violently in recent years.
作者
王伟
阿里木·赛买提
马龙
葛拥晓
吉力力·阿不都外力
WANG Wei;SAMAT Alim;MA Long;GE Yongxiao;ABUDUWAILI Jilili(State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China;Research Center for Ecology and Environment of Central Asia,Chinese Academy of Sciences,Urumqi 830011,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《生态学报》
CAS
CSCD
北大核心
2022年第4期1300-1314,共15页
Acta Ecologica Sinica
基金
国家自然科学基金(U1903115,42071424)
中国科学院青年创新促进会项目(2018476)。
