PROGRESS IN GEOGRAPHY ›› 2022, Vol. 41 ›› Issue (3): 437-450.doi: 10.18306/dlkxjz.2022.03.007

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Spatiotemporal dynamics and driving factor analysis of ecological quality change in the Lhasa urban circle from 1994 to 2017

KONG Lingling1,2,3(), FENG Xianfeng1,2,*(), WU Shuang1,2, LIU Zichuan1,2, YAO Xuanchu1   

  1. 1. Institute of Geographic Sciences and Nature Resources Research, CAS, Beijing 100101, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Guangdong Academy of Environmental Sciences, Guangzhou 510045, China
  • Received:2021-02-25 Revised:2021-06-02 Online:2022-03-28 Published:2022-05-28
  • Contact: FENG Xianfeng E-mail:kll_linxi1009@163.com;fengxf@lreis.ac.cn
  • Supported by:
    Strategic Priority Research Program of Chinese Academy of Sciences, No(XDA20040401)

Abstract:

The Lhasa urban circle is a prominent area of ecological environment change and urbanization in the Tibet Autonomous Region. In recent years, there have been ecological and environmental problems such as grassland degradation and soil desertification. The monitoring of the ecological quality of the region is urgent, but currently there is a lack of fine-scale monitoring of ecological quality status in the area. In view of this gap, by taking advantage of the parallel computing capacity of the Google Earth Engine remote sensing big data platform and based on Landsat TM/ETM+ satellite imagery, this study used the remote sensing ecological index method to monitor the temporal and spatial changes of the ecological quality of the Lhasa urban circle from 1994 to 2017, analyzed the climatic and land use transfer factors of ecological quality changes, and explored the temporal and spatial distribution characteristics of comprehensive climate driven ecological quality changes. The results show that: 1) During 1994-2017, the ecological quality of the Lhasa urban circle was good, showing a gradual decrease in space from the southwest to the northeast, and the overall ecological quality showed an improving trend, with an improvement proportion of 45.98%. 2) Heat has been the main internal controlling factor of ecological quality changes, which had a negative impact. 3) Vapor pressure deficit and climate water deficit have been the main climatic driving factors of ecological quality changes, and the transfer of grassland has been the main driving factor of land use. 4) Comprehensive climatic driving force has weakened in the past 20 years, and the impact has gradually increased from the southwest to the northeast. The in-depth analysis of this study may provide a scientific guidance for the protection of the plateau ecological environment and the healthy development of urbanization in Tibet.

Key words: Lhasa urban circle, ecological quality, driving factor analysis, climate driving, Google Earth Engine platform