Temporal and Spatial Distribution Characteristics of Annual Precipitation in Chengdu

At present, meteorologists have studied the laws of climate change throughout China and applied the results to many meteorological fields. The Chengdu area is located on the border of the northwestern plateau of Sichuan and the Sichuan Basin. The climate and environment are diverse. In order to understand the temporal and spatial characteristics of the precipitation field in Chengdu, and to predict the development trend of precipitation in Chengdu in a short time, this article uses 44a hourly precipitation data of 12 ground stations in Chengdu as reference materials. The two-dimensional interpolation method is used to fill in the missing data. The empirical orthogonal function analysis method is used to study the spatial distribution of precipitation fields, and the changing trend of precipitation in Chengdu area in 44a is analyzed by moving average. The results show that there are two main spatial types of annual precipitation in Chengdu. First, the changes in precipitation in Chengdu are highly consistent, that is, the city is either rainy or drizzle throughout the year. Second, the change pattern of precipitation in the northwest and southeast regions of Chengdu is opposite, that is, there is more rainfall in the northwest region and less rainfall in the southeast region, or less rainfall in the northwest region and more rainfall in the southeast region. It can be obtained from the time coefficient that the number of years of the modal one distribution model accounts for 54.5% of the total years, which is consistent with the cumulative variance contribution rate of the modal one, which can explain that the modal one is the main spatial type of precipitation field in Chengdu. The annual precipitation in Chengdu is generally decreasing.