Analysis on the spatio-temporal distribution of precipitation in Yunnan province, Southwest China

In order to improve understanding of precipitation trend and variation, as well as to reach better control of water resource, in this paper, the spatio-temporal distribution of precipitation in Yunnan province, southwest China, was analyzed using the meteorological data of 32 selected stations from 1957 to 2006. The trend coefficient was calculated, the anomalous variation and 5-year running mean were graphed; besides, GIS software was used to interpolate the spatial distribution. According to the results: 1) The precipitation in Yunnan province shows fluctuation in the last 50 years, which can be divided into three periods with significant trend coefficients (R=0.280, -0.177 and -0.121 respectively); 2) the average monthly precipitation distribution shows a single peak distribution with peak at July and the contribution of summer alone above 50%; 3) the spatial distribution of average annual precipitation is asymmetric, that is, more in southern and western area while less in northern and central area; 4) the precipitation distribution varies with seasons: in spring, summer and autumn, the heaviest precipitation occurs in JiangCheng area, whereas in winter in Gongshan area.