玉溪市区域降水特征及城市化影响分析

An Analysis on Characteristics of Regional Precipitation and Influence of Urbanization in Yuxi City

根据玉溪市1963-2018年城市和郊区降水量资料,分析了玉溪市降水特征,采用城区与郊区降水量对比的方法,研究了城市发展对玉溪市降水量的影响。结果表明:玉溪市年降水量呈缓慢减少趋势,特别是2000年以后减少趋势明显;月降雨量最多在8月,最少在3月,而且城区月降水量比郊区多;降水量有干湿季之分,降水主要集中于雨季5-10月,干季降水量约占全年15.83%,雨季降水量占全年的84.17%,而且雨季降水量城区明显多于郊区。通过玉溪市降水量日数分析,最多的是小雨,最少的是暴雨,城区降雨日数比郊区多,城市发展对大雨和暴雨的增雨作用更加明显。总之,玉溪市城市发展有使城市及其下风方向降水量增加的趋势。

According to the precipitation data of Yuxi City from 1963 to 2018,the precipitation characteristics of Yuxi City are analyzed using the method of precipitation comparison between urban and suburban areas.The influence of urban development on precipitation in Yuxi City is studied and results are obtained.The annual precipitation of Yuxi City is decreasing slowly,especially after 2000.The trend of decrease is obvious.The maximum monthly rainfall is in August and the minimum is in March.Moreover,the monthly precipitation in the urban area is more than that in the suburban area.Precipitation can be divided into the dry and the wet seasons.Precipitation is mainly concentrated in the rainy season from May to October.The precipitation in the dry season accounts for 15.83%and that in the rainy season accounts for 84.17%.In addition,the precipitation in the urban areas is significantly higher than that in the suburban areas in the rainy season.According to the precipitation days in Yuxi City,the most frequent is light rain and the least is heavy rain.There are more rainfall days in the urban areas than in the suburban areas.The effect of urban development on heavy rain and rainstorm is more obvious.In short,the development of Yuxi City has the trend of increasing precipitation in the city and the areas in its downwind direction.