The study looked at how moisture moves over Asia during the summer and how it affects rainfall in China. They used data from 1948 to 2005 to analyze this. The results showed that the Asian monsoon region is a big source of moisture during summer, with most coming from the Bay of Bengal. The Indian and East Asian monsoon areas have their own moisture convergence centers. The moisture transport changes throughout the summer, reaching its peak in July. The South China Sea plays a crucial role in providing moisture to China. The weakening of the East Asian summer monsoon has led to less rainfall in North China. Over the Yangtze River valley, there has been an increase in moisture convergence, leading to more heavy rainfall since the 1980s.