Research on the Temporal and Spatial Changes Characteristics of the Drought of Natural Vegetation in the Yangtze River Source Area Based on CWSI

Abstract

Under the combined effect of global climate change and local regional environmental change, drought has developed into a natural disaster with high incidence on the earth. As the Yangtze River is the mother river of Chinese civilization, the drought phenomenon in the source area in recent decades has seriously affected and restricted the development of local agriculture and economic society. With the long-term practice of remote sensing technology, researchers have improved drought monitoring methods, including crop water stress index. Crop water stress index (CWSI) is widely used in agricultural drought research based on the principle of heat balance. In this paper, the spatial and temporal characteristics of drought in the Yangtze River source area and its influencing factors were analyzed by using crop drought index method. The CWSI value of the source area of the Yangtze River featured a slightly downward trend from 2001 to 2018. With a strong spatial heterogeneity in distribution, it gradually decreases from west to east. The severest drought occurs in summer and autumn, and the regions that are mostly influenced by temperature are mainly in southwest part and the ones mostly influenced by precipitation are mainly in east part. By analyzing the temporal and spatial distribution characteristics of drought and the correlation of meteorological factors, this paper provides an effective basis for drought prevention and control in the Yangtze River source area, and then promotes the accelerated development of agriculture and economic society in the Yangtze River source area of our country.