Assessing the soil moisture-vegetation mutual feedback relationship in different climatic regions of mainland China

Abstract

Exploring the mutual feedback relationship between vegetation and soil moisture (SM) is highly important for water resource management, soil and water conservation and terrestrial carbon sinks under changing environment. However, the mutual feedback relationship between vegetation and SM is not fully understood. To this end, this study firstly introduced convergent cross mapping (CCM) to evaluate the feedback relationship between NDVI and SM in in different climatic regions of China. The spatial trend coupling relationship was also analyzed. The results indicated that (1) NDVI was positively with SM in most areas of China, while the proportions of negatively correlated and uncorrelated areas increase with depth. (2) The causality is different for different depth. NDVI and SM1/SM2/SM3 were mutual feedback in most areas of China (65.52%/70.41%/76.4%). In areas with poor correlation results, CCM can better explain the relationship between SM and NDVI. (3) The coupling relationship between SM and NDVI is primarily divided into the co-increasing area of the northeastern Qinghai-Tibet Plateau, the vegetation greening-SM decreasing area in Central China, and the mixed area in Northeast China. The research results have important reference significance for ecological engineering management, the sustainable use of land and water resources, and carbon sequestration.