浙江省1971~2016年极端降水指数时空变化特征

Spacial-Temporal Variation of Extreme Precipitation Indices in Zhejiang Province from 1971 to 2016

摘要: 本文选用了1971~2016年浙江省22个测站的逐日降水数据，选取了11个极端降水指数，运用相关分析、线性倾向估计、M-K突变检验、滑动t检验、显著性检验和反距离加权插值等方法，对数据进行处理，分析了浙江地区46年来的极端降水时空变化特征。旨在为同类地区极端降水诊断和预测、决策和部署提供指导。结果表明：1) 浙江地区降水往降水量更大、持续时间更长发展。2) 仅湿日总降水量存在突变年份，1977年，其余指数除连续干日数持续下降以外，在70年代至80年代都存在波动变化期，未达到突变强度，不影响总体上升。3) 平均空间分布所符合的两项分布规律：从西南到东北递减的分布，和自东南沿海向西北递减。因此纬度，以及东部临海因素须考虑。4) 单站层面上，干指数普遍下降，湿指数主要上升。倾率越大的测站，越是变化得显著，降水十分集中。5) 中雨日数、大雨日数、暴雨日数和强降水量对湿日总降水量的增长贡献率最大。纬度与浙江省极端降水指数相关性最好。

Abstract: Based on daily precipitation data sets of 22 meteorological stations from 1971 to 2016 of Zhejiang province, 11 extreme precipitation indices were analyzed to study the spacial-temporal variation of extreme precipitation in Zhejiang during 46 years. Methods including correlation analysis, linear tendency estimation, Mann-Kendall test, moving t test, significance test and IDW were used.  It is aimed to offer guidance for the diagnosis, prediction, decision and deployment of extreme precipitation in similar regions. The results were as follows: 1) The precipitation in Zhejiang is getting greater in amount and longer in time. 2) Only the PRCPTOT had the mutation year 1977. Except that CDD always declined, other indices had fluctuations from 1970s to 1980s. Even so, the strength is not strong enough to influence the total upward trend. 3) According to two rules for average spatial distribution: the decreasing from southwest to northeast and from southeast to northwest, the latitude and costal effect must take into consideration. 4) From the perspective of single station, the CDD decreased while wet indices mainly increased. Additionally, the changes were more significant where the rate were larger, which leaded to the intensive precipitation. 5) R10 mm, R20 mm, R50 mm and R95 contribute most to the increasing PRCPTOT. And latitude has good correlation with the indices.