Monitoring and assessment of desertification reversal in ecologically fragile areas: A case study of the Mu Us Sandy Land.

Abstract

Desertification is a major obstacle to global sustainable development, and effective monitoring and understanding of its driving factors are crucial to the realization of sustainable development. Driven by national policies, the Mu Us Sandy Land has effectively reversed desertification, showing multiple win-win results in ecological, economic and social benefits. However, due to the lack of long-term continuous dynamic monitoring data, its dynamic development pattern and multidimensional driving factors are still controversial. Therefore, it is urgent to implement long-term desertification monitoring and quantitative assessment, especially to assess the contribution of ecological restoration policies to desertification control. Based on the Google Earth Engine and combined with multi-source remote sensing data, this study produced a set of high-precision LUCC and FVC data of the Mu Us Sandy Land from 1986 to 2020. The dataset of LUCC was verified by random sampling based on field surveys and remote sensing images, and the overall accuracy was 90.03%. Based on these two sets of data, the spatiotemporal dynamic characteristics of desertification and ecological restoration in the region are further analyzed and revealed. We found that the desertification land in the Mu Us Sandy Land decreased by 69.45% from 1986 to 2020, and the gravity center gradually moved to the northwest away from human aggregation. The area of various vegetation types increased and expanded to the original desertification area. The average FVC in the Mu Us Sandy Land increased by 26.98%, and Yulin contributed the most to the growth of FVC. These results show that the desertification in the Mu Us Sandy Land has been basically reversed. This study also provides solid data support and a scientific basis for evaluating the effectiveness of ecological restoration policies and guiding future desertification control.