Environmental sensitivity assessment of land desertification in the Hexi Corridor, China

Abstract

Due to extreme climatic conditions and unreasonable human activities, the Hexi Corridor is facing a serious threat of desertification. Based on the soil quality index (SQI), geomorphological quality index (GQI), climate quality index (CQI), vegetation quality index (VQI) and anthropogenic quality index (AQI), this study established a desertification environmental sensitivity index (DESI) model for arid and semiarid areas to identify the distribution pattern of potential desertification risks in the Hexi Corridor. On this basis, the five indicators were divided into three categories according to the risk attribute characteristics, and their development trend and distribution law were explored on the three-time scales of stable, slow change and seasonal change. Moreover, correlation analysis, cluster analysis and redundancy analysis were used to reveal the potential connection between decision factors and indicators of the DESI. The results showed that 67.4% of the total area had critical sensitivity to desertification in the study area, and the overall trend increased from southeast to northwest. The main decision factors for this phenomenon were the VQI and CQI, which were dominated by climate conditions. The VQI was the lowest in the area, but its sensitivity to desertification was significantly alleviated in summer and autumn, which was consistent with the seasonal variation in the CQI. However, the AQI showed the best land condition and showed no significant change from 2000 to 2020. The SQI and GQI showed moderate and good land conditions, respectively. These factors with strong stability have mainly played an initial limiting role in the process of desertification. This study can provide a scientific basis for the formulation of desertification control and ecological protection measures and is of great significance to the safety and stability of the ecological environment and the sustainable development of society and the economy in arid and semiarid areas.