Arid Zone Research ›› 2025, Vol. 42 ›› Issue (2): 360-371.doi: 10.13866/j.azr.2025.02.15

• Ecology and Environment • Previous Articles     Next Articles

Spatial-temporal variation and driving forces analysis of ecological environment quality in arid counties based on GEE: A case study of Alxa Left Banner

LI Qi1(), DANG Guofeng1, YU Tengfei2(), ZHANG Lang1, CHEN Weiyu2   

  1. 1. College of Geography and Environment Science, Northwest Normal University, Lanzhou 730070, Gansu, China
    2. Alax Desert Eco-hydrological Experimental Research Station, Northwest institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China
  • Received:2024-08-15 Revised:2024-12-17 Online:2025-02-15 Published:2025-02-21
  • Contact: YU Tengfei E-mail:176924194@qq.com;yutf@lzb.ac.cn

Abstract:

Objective, accurate, and timely evaluation of the spatiotemporal changes and driving forces of ecological environment quality is of great significance for the formulation of ecological protection plans and policies. Taking Alxa Left Banner as an example, this study constructs a Remote Sensing-based Ecological Index (RSEI) for arid regions based on the Google Earth Engine (GEE) platform and analyzes the spatiotemporal changes and driving forces of RSEI over the past 30 years (1991-2021). The study shows that: (1) Over the past 30 years, the RSEI of Alxa Left Banner has shown a fluctuating upward trend, with the maximum RSEI in 2012 (0.360) and the minimum in 2007 (0.264). (2) Over the past 30 years, the area of ecological improvement (RSEI>0.2, 3.15%) in Alxa Left Banner is larger than the area of degradation (RSEI<-0.2, 2.48%), with the largest area showing no change (-0.2<RSEI<0.2, 94.37%). Regions with poorer RSEI are mainly distributed in bare land areas, while the RSEI of forest, grassland, farmland, and impervious surface areas has gradually improved. (3) From 1991 to 2021, the Global Moran’s I index ranged between 0.600 and 0.650, indicating a high degree of clustering. (4) According to the results of the linear mixed-effects model, human activities account for 89% of the changes in RSEI, while climate change accounts for 11%. In summary, over the past 30 years, the overall ecological environment quality in the Alxa Desert area has gradually improved, with significant improvements in the northern edge of the Tengger Desert, primarily due to human activities, especially the aerial seeding afforestation projects.

Key words: remote sensing-based ecological index, GEE, spatial autocorrelation, arid region