Based on the historical records of the drought and flood disasters during 1480-1940 AD, this paper reconstructs the sequences of wetness index (WI) and drought and flood disasters. The AA. find a good identical relationship between the fluctuation
of WI sequence and the δ O18 record of the GISP2 ice core in Greenland, which shows an apparent monsoonal disposal pattern of moisture and temperature. The results show that the western and northern parts of Guangdong have undergone drastic changes