基于不同时间尺度的降雨时空演变规律分析

Analysis of spatio-temporal evolution of rainfall based on different time scales

为研究降雨时空演变特征规律,基于金华市区1954—2018年降雨量资料,运用5 a滑动平均、累积距平法和线性趋势法分析了降雨演变的趋势。通过Mann-Kendall检验和滑动t检验研究了降雨发生突变的年份,采用Morlet小波探究了降雨变化的周期性。结果表明:金华市区年内降雨量总体呈线性上升的趋势;年降雨量存在显著性突变年份为2009年;金华市区年降雨量在不同时间尺度上呈现不同的“丰枯交替”的周期性变化,主变化周期为45 a、27 a、19 a,其中45 a为第一主变化周期;金华市区在近期仍将处于偏丰水年份,中长期逐渐过渡到偏枯水年份。研究成果对金衢盆地水资源综合利用和气候变化特征研究具有借鉴意义。

In order to study the spatio-temporal evolution characteristics of rainfall,the precipitation data from 1954 to 2018 in Jinhua City was used to analyze the trend of rainfall evolution by 5 a moving average,cumulative anomaly method and linear trend method.The year of the rainfall sudden change was studied by the Mann-Kendall test and sliding t-test,and the periodicity was explored by the Morlet wavelet.The results showed the annual rainfall trend was a linear upward in Jinhua City,and the rainfall sudden change year was 2009.The year of significant abrupt change in annual rainfall is 2009 in Jinhua City.The annual rainfall showed different periodic changes of"alternating between abundant and dry"in different time scales,and the time scales were 45 a,27 a and 19 a with 45 a in the majority in Jinhua City.This region will still be in wet year in the next few years,and then transits from the abundant year to the dry year.These studies have been significance to research the comprehensive utilization of water resources and the characteristics of climate change in Jin-qu basin.