四川省近60年降水变化特征分析

Characteristic Analysis of Precipitation Change in Sichuan Province during Recent 60 Years

摘要: 本文利用四川省1961~2017年37个气象站的逐日降水观测数据，分析了四川省降水变化特征，结果表明：1) 仅60年来四川省年降水量没有发生显著变化，年降水量在东南地区呈下降趋势，然后向西北地区逐渐过渡为增加趋势，但仅部分区域达到显著性水平。2) 秋季降水量呈显著下降趋势，其余季节降水量无显著变化；四季降水量在东南地区呈下降趋势，然后向西北地区逐渐过渡为增加趋势，其中仅夏季没有达到显著性水平。3) 不同等级降水日数在全省绝大多数地区均呈增加趋势，但只有小雨降水日数在全省均通过了90%的信度检验，暴雨仅在甘孜州西部、达州和广安通过了90%的信度检验。小雨降水强度呈下降趋势，且在绝大多数地区通过了90%的信度检验，大雨降水强度的变化趋势在全省都没有通过90%的信度检验，暴雨和中雨降水强度的变化仅在部分区域通过了90%的信度检验。

Abstract: Based on the daily precipitation measured data of 37 meteorological stations in Sichuan Province from 1961 to 2017, the change characteristics of precipitation are analyzed. The results show that: 1) There is no significant change in annual precipitation in Sichuan Province during the recent 60 years. The annual precipitation shows a downward trend in the southeast, and then gradually transits to an increasing trend toward the northwest, but only do some regions reach a significant level. 2) The precipitation in autumn shows a significant downward trend, and there is no significant change in other seasons. The precipitations of four seasons show a downward trend in the southeast, and then gradually transits to an increasing trend in the northwest, of which only in summer do not reach a significant level. 3) The number of precipitation days of different grades show an increasing trend in most areas of the province, but only the number of light rain precipitation days passes the 90% level significance in the province, and the rainstorm passes the 90% level significance only in the west of Ganzi Prefecture, Dazhou and Guang’an. The light rain precipitation intensity shows a downward trend and passes the 90% level significance in most areas. The change trend of heavy rain precipitation intensity does not pass the 90% level significance in the whole province. The change of rainstorm and moderate rain precipitation intensity only passes the 90% reliability test in some areas.