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Arid Land Geography ›› 2022, Vol. 45 ›› Issue (2): 467-477.doi: 10.12118/j.issn.1000–6060.2021.199

• Earth Information Sciences • Previous Articles     Next Articles

Spatiotemporal change and driving force of vegetation in Ebinur Lake Basin

REN Liqing()   

  1. Urumqi Meteorological Satellite Ground Station, Urumqi 830011, Xinjiang, China
  • Received:2021-05-02 Revised:2021-08-10 Online:2022-03-25 Published:2022-04-02

Abstract:

Vegetation is one of the sensitive factors reflecting the changes of the land ecosystem and plays an essential role in maintaining and regulating ecosystem stability. In this study, the Ebinur Lake Basin with complex terrain is located northwest of Xinjiang, China and has severe ecological and environmental degradation. Additionally, the ecological environment spatial specificity is obvious. Previous studies have only discussed the influence of climate and elevation on vegetation normalized difference vegetation index (NDVI) in the Ebinur Lake Basin. However, no research has been conducted on other natural and human activity factors, such as the type of vegetation and land use. Additionally, the most relevant analyses could not reveal the complex spatial anisotropy of the Ebinur Lake Basin and study the driver factors of NDVI variation quantitatively. Therefore, this paper takes the ecologically fragile area, i.e., the Ebinur Lake Basin, as the research area. The MODIS vegetation NDVI data from 2000 to 2020 and unary linear regression methods are used to analyze the characteristics of vegetation NDVI from 2000 to 2020. Then, the geographic detector model is used to investigate the influence of natural and human factors and their interaction with vegetation coverage. Furthermore, analyzing the appropriate range (categories) of various influencing factors promotes vegetation growth. The results are as follows. (1) From 2000 to 2020, the average vegetation cover in the Ebinur Lake Basin increased at the rate of 0.035·(10a)-1, medium grade (0.4-0.6), medium and high grade (0.6-0.8), and high grade (0.8-1.0) vegetation area increased significantly. The ecological environment was effectively improved. The improved areas were distributed in the central and western regions. The significantly improved areas were located in the central part of the Ebinur Lake Basin. Meanwhile, severely degraded areas were scattered in the central part of the Ebinur Lake Basin. (2) The land use type, vegetation type, and soil type factors had a greater influence on the spatial distribution of vegetation NDVI than other factors as the main influencing factors. Elevation was the secondary factor. The precipitation, geomorphological type, temperature, slope, and slope had little direct impact on the spatial distribution of vegetation in the Ebinur Lake Basin. Compared with natural factors, human factors played a leading role in vegetation NDVI changes in the Ebinur Lake Basin. The interaction between natural and human factors on vegetation NDVI was dominated by nonlinear and double-factor enhancements, and there was no independent relationship. (3) Cultivland, cultivated vegetation, artificial soil, medium-undulating mountains, elevation range of 2177-2558 m, precipitation range of 228-245 mm, temperature range of 4.74-5.25 ℃, aspect of 157.5°-202.5°, and slope of 25°-35° were suitable for vegetation growth. This study explored the vegetation spatial differentiation and driving mechanism using the geographic detector model. The results of this study will provide a scientific basis for the ecological protection of the Ebinur Lake Basin.

Key words: normalized vegetation index (NDVI), vegetation change, geographic detector, Ebinur Lake Basin