Monitoring the evolution process of karst desertification and quantifying its drivers in the karst area of Southwest China.

Abstract

Karst desertification (KD) is a unique desert ecological phenomenon occurring in the karst region of Southwest China (KRSC). Studying the KD evolution process and distinguishing the influences of human activities and climate factors on KD are essential for restoring KD areas. This article is based on MODIS remote sensing data and ERA5-Land data. Additionally, multiple linear regression models, correlation analysis, and residual analysis are utilized to analyze the spatiotemporal evolution characteristics of KD in the southwest region of China from 2000 to 2020. This study aims to differentiate the impacts of human activities and climate change on the desertification process in karst areas. (1) In the southwest region of China, the overall KD shows an intensifying trend at both ends of the study area and an ameliorating distribution pattern in the central region. In particular, Guizhou province, which is located in the center of the study area, demonstrated significant suppression in the KD process from 2000 to 2020. (2) In the southwest karst region, there are significant spatial differences in the correlation between the KD process and precipitation, temperature, and radiation. Temperature is significantly negatively correlated in most parts of Yunnan. (3) According to the residual analysis, approximately 89.62% of the karst areas in the southwest are influenced by climate, while 10.38% are influenced by human activities. Climate change has a relatively small impact on the ability to improve KD compared to the disruptive influence of human activities. Some human activities, such as afforestation, in which grassland and cultivated land are converted to forest, play a substantial role in inhibiting the KD process. Conversely, the rapid expansion of urban areas tends to exacerbate KD in adjacent regions. Therefore, this study of the evolution process of KD in Southwest China can provide a scientific basis for monitoring and controlling KD and provide theoretical support for coping with the challenges posed by KD to China's ecological environment.