Arid Zone Research ›› 2022, Vol. 39 ›› Issue (4): 1076-1089.doi: 10.13866/j.azr.2022.04.09

• Water Resources and Utilization • Previous Articles     Next Articles

Analysis of Qinghai Lake expansion and lakeside sandy land change characteristics based on GF-1 satellite

ZHU Cunxiong1,2(),SHI Feifei1,2,QIAO Bin1,2,ZHANG Juan1,2,CHEN Guoqian1,2()   

  1. 1. Qinghai Province Key Laboratory of Disaster Prevention and Mitigation, Xining 810001, Qinghai, China
    2. Qinghai Province Institute of Meteorological Sciences, Xining 810001, Qinghai, China
  • Received:2021-11-08 Revised:2022-01-23 Online:2022-07-15 Published:2022-09-26
  • Contact: Guoqian CHEN E-mail:zhucunxiong_2008@126.com;guoxi_chen@163.com

Abstract:

In the context of climate change, the ecological environment of the Qinghai-Tibet Plateau has undergone a series of changes, including the increase in the lake area. As the largest inland plateau saltwater lake in China, Qinghai Lake is located in the Northeast of the Qinghai-Tibet Plateau and is an important part of the “Asian water tower.” Since 2005, Qinghai Lake has demonstrated area expansion. Therefore, understanding the causes of changes in Qinghai Lake and the impact of such changes on the surrounding environment (such as lakeside sandy) is crucial. Based on multisource satellite and meteorological station data, combined with the snow cover, glacier, permafrost, and meteorological data in the basin, this paper analyzed the dynamic change characteristics of the lake area, lakeside sand area, and sand vegetation coverage in Qinghai from 2013 to 2020. The following results are presented. (1) Qinghai Lake continued to expand in recent years, especially after 2017. The expansion affected the areas of Buha River entering the lake, Shaliu River entering the lake, Sand Island, Bird Island, and Spring Bay. The interannual fluctuation and expansion trend of the Gahai sublake affiliated to Qinghai Lake is consistent with that of the main lake, and its expansion rate is lower than that of the main lake. (2) The expansion of the lake led to the extensive inundation of the zigzagging low-lying areas, and the shoreline length showed a trend of fluctuating reduction, especially after 2017. The shoreline significantly decreased mainly due to the inundation of the lake in the lakeside sandy land and sand dike, leading to a fluctuating reduction trend in the area of the lakeside sand area; among which, the Bird Island sand area was completely submerged. (3) The vegetation in the sand region is characterized by low coverage, uneven distribution, spatial aggregation, obvious interannual fluctuation, and insufficient stability. (4) The Qinghai Lake basin presents a trend of warm and humid climate, increasing snow cover area and snow cover days, glacier retreat, and shallow maximum frozen soil depth. (5) The precipitation in the basin increased, and the snow cover area increased in winter. The increase in snow cover days affected lakes and rivers, which was significantly correlated with the change in lake area (P < 0.01). Temperature rise, seasonally frozen ground degradation, and glacier retreat indirectly affect water resource allocation in the basin and have an impact on the inflow of Qinghai Lake. The method and extent of the impact of frozen soil on the lake need further study. (6) The regional warm and humid climate background has created a good opportunity for ecological restoration projects in arid sand areas. Meanwhile, the expansion of Qinghai Lake has had a certain impact on bird habitats and surrounding infrastructure. However, focusing on the prevention of regional potential ecological risks is still necessary.

Key words: Qinghai Lake, GF1 satellite, random forests, beach sands, desert vegetation