Abstract:

Based on the daily precipitation data from 1959 to 2016 from Emei Mountain station and Emei, Leshan, Jiajiang stations of Sichuan Province, the variation characteristics of rainfall and rain days for different orders of magnitude in Emei Mountain and its surrounding areas were systematically studied by using the statistical diagnostic analysis methods. The results show that the precipitations for light rain, moderate rain, heavy rain and torrential rain in Emei Mountain were more than those in its surrounding areas with low altitude, but the proportion of precipitation for torrential rain to annual precipitation in Emei Mountain was less than that in its surrounding areas, but for light rain, moderate rain and heavy rain, it was more. And the rainfall days with different orders of magnitude in Emei Mountain were more than those in its surrounding areas, especially the days for light rain and moderate rain were significantly more. However, the proportion of rain days for different orders of magnitude rainfall to annual rain days in Emei Mountain was close to that in its surrounding areas, and the contribution of light rain days to annual rain days was the greatest, followed by moderate rain, heavy rain, and torrential rain was the least. For light rain, moderate rain and heavy rain, there were many rain days and much rainfall in Emei Mountain, while there were relatively few rain days and little rainfall in its surrounding areas, but the intensity of their rainfall in two places were close. For torrential rain, the rain days in two places were close, and the rainfall in Emei Mountain was larger than that in its surrounding areas, but the rainfall intensity in Emei Mountain was slightly less than that in its surrounding areas. The rainfall and rain days for light rain, moderate rain and torrential rain in Emei Mountain and its surrounding areas appeared a reducing tendency during 1959-2016, and the reducing rate was faster in Emei Mountain. However, the changes trend of rainfall and rain days for heavy rain in two places weren’t obvious. Under the global climate change, the responses of light rain, moderate rain and torrential rain to regional climate change in Emei Mountain were more significant than that in its surrounding areas with low altitude in the form of earlier time and stronger intensity. However, the responses of heavy rain to regional climate change weren’t prominent in two places. Therefore, the responses of weak rainfall and strong rainfall to regional climate change were more significant, which reflected the complexity of regional climate response in mountains and its surrounding areas.

Key words: Emei Mountain, surrounding areas, rainfall, rain day, regional climate responses

摘要：

基于峨眉山站及周边地区峨眉市、乐山市、夹江县3站1959—2016年逐日降水观测数据，应用统计诊断分析方法，系统研究了峨眉山与周边地区不同强度降水的雨量及雨日变化特征。结果表明：高海拔峨眉山的小雨、中雨、大雨和暴雨雨量都高于低海拔周边地区，且占年降水量的比例除暴雨雨量比例小于周边地区外，其他等级雨量比例均高于周边地区；峨眉山不同强度降水的雨日都比周边地区偏多，尤其是小雨、中雨明显偏多，但各量级降水的雨日占年雨日比例较接近，两地雨日贡献都是小雨最大，其次为中雨、大雨，暴雨最小。对于小雨、中雨和大雨，峨眉山雨日多、降水量大，周边地区雨日少、降水量小，但其降水强度接近；对于暴雨，两地暴雨雨日接近，而雨量则峨眉山大于周边地区，但其降水强度略小于周边地区。近58 a来，峨眉山和周边地区小雨、中雨和暴雨雨量及雨日均呈减少趋势，且峨眉山减少速率较周边地区更快，但两地大雨雨量和雨日增多或减少趋势不明显。在全球气候变化下，峨眉山小雨、中雨、暴雨的区域气候响应比低海拔周边地区更显著，表现在时间更早、强度更强，但两地大雨的区域气候响应不突出。可见，弱降水、强降水的区域气候响应更加显著，这反映了山地及周边区域气候响应的复杂性。

关键词: 峨眉山, 周边地区, 降水量, 雨日, 区域气候响应