Spatial-temporal trends and driving mechanisms of land degradation sensitivity in the southern region of China

Abstract

Evaluating land sensitivity to degradation and its driving factors is crucial due to both environmental and human influences. This helps to identify vulnerable regions and develop effective land management strategies. This study examines land degradation trends and driving factors in southern China from 2000 to 2020 using Mediterranean Desertification And Land Use (MEDALUS) and Geographical Detector models. Eighteen factors are grouped into four indices: Vegetation Quality Index (VQI), Climate Quality Index (CQI), Management Quality Index (MQI), and Soil Quality Index (SQI) to formulate the Land Degradation Sensitivity Index (LDSI). The results indicated that fragile and critical land degradation sensitivity is primarily distributed in the Yangtze River, Dongting Lake, Xinjiang, and Taihu basins of the study regions. Quantitatively, the critical sensitivity class of LDSI comprised 13.35 %, 16.95 %, and 17.95 % of the total areas in 2000, 2010, and 2020, respectively. Over the last 20 years, 23.2 % and 16.4 % of ’Potential’ lands became ’Fragile’ and ’Critical’, respectively. These trends indicate the ongoing shift from less degraded to more degraded states. The interaction detector results showed that the combinations of VQI ∩ CQI, and VQI ∩ SQI had the most significant effects on LDSI. Erosion protection (EPs), drought resistance (DRs), fire resistance (FRs), wind speed (WindSpe), precipitation (PRE), land use intensity (LUI), and soil group (SoilGr) are the main drivers. To effectively combat land degradation, it is essential to address the key factors that contribute to it. The study provided a scientific foundation for understanding land degradation sensitivity in the study regions and a global reference for quantifying its causes.