Characteristics of Precipitation Variation and Potential Drought-Flood Regional Responses in Yunnan Province From 1954 to 2014
Analyzing the characteristics of spatio-temporal variability of precipitation is very important to prepare against droughts and floods. Based on the monthly rainfall data from 1954 to 2014 collected from 32 meteorological sites in Yunnan province, the spatio-temporal variability of the precipitation and drought-flood regional responses were analyzed using the linear regression, RBF spatial interpolation, wavelet analysis, R/S analysis and Z-index. The results show that the precipitation of 3 seasons, except for the spring, has indicated a fluctuant downward trend, and the annual rainfall tends to decrease at a rate of 8.1 mm/10a in the last 61 years in Yunnan province, moreover, the results of wavelet analysis and Hurst index reveal that the precipitation will maintain a decreasing trend in the future. The average annual rainfall decreases gradually from Xishuangbanna to Lijiang-Diqing. Furthermore, the historical precipitation has a primarily downward trend, while secondly an increasing trend in partial areas. Interestingly, the spatial distribution of the decreasing trend has shown a characteristic of symmetry, but the spatial distribution of the increasing trend seems randomly scattered. The periodic oscillation of the annual rainfall is concentrated in the expectant of 2 years, 6 years, 8 years, 18 years and 28 years, and especially in expectant 28 years it has the strongest energy. The rate of drought trend (KL=0.359) is faster than that of flood trend (KI=-0.071), and the downward trend of the annual precipitation can also explain this phenomenon There are 5 sub-prefectures that the droughts appear more often than the other states in Yunnan province, and which are Diqing, Dehong, Xishuangbanna, Honghe and Chuxiong. In addition, there are 3 sub-prefectures and 2 cities where floods appear frequently, which are Nujiang, Dali, Wenshan, Puer and Shaotong.
precipitationdrought-floodwavelet analysisZ-IndexR/S analysisYunnan province
NETL
NSTL
万方数据
维普
