近20年重庆江津区旱涝时空特征分析

Spatial and temporal characteristics of drought and flood in Jiangjin district of Chongqing in recent 20 years

极端天气频发背景下,旱涝灾害是影响重庆市的主要自然灾害之一,为了全面了解重庆市降水和旱涝时空特征,文章以重庆市江津区为例,基于Z指数,利用M-K趋势检验、突变检验、小波分析和空间插值分析其降水时空特征。结果表明:(1)江津区近20年洪涝频率为31.82%,干旱频率为22.73%,夏、冬季易出现极端旱涝;(2)降水年际变化呈上升趋势,春、秋两季降水增加,夏、冬两季降水减少,降水变化第一主周期为14 a;(3)降水空间分布为东南多西北少。除夏季外,春、秋、冬季的平均降水量均由东向西递减。研究结果对江津区防涝抗旱、工程建设等工作具有重要意义。

Under the background of frequent extreme weather,drought and flood disasters are one of the main natural disasters affecting Chongqing.In order to comprehensively understand the spatio-temporal characteristics of precipitation and drought and flood in Chongqing,this paper takes Jiangjin district of Chongqing as an example,and analyzes its temporal and spatial characteristics of precipitation based on Z-index by using M-K trend test,mutation test,wavelet analysis and spatial interpolation.The results show that:(1)The frequency of flood and drought in Jiangjin district in the past 20 years is 31.82%and 22.73%,and the extreme drought and flood are easy to occur in summer and winter.(2)The interannual variation of precipitation showed an upward trend,with the precipitation increasing in spring and autumn and decreasing in summer and winter.The first main cycle of precipitation variation was 14 a.(3)The spatial distribution of precipitation is more in southeast and less in northwest.Except for summer,the average precipitation in spring,autumn and winter decreased from east to west.The research results are of great significance to the waterlogging and drought prevention and engineering construction in Jiangjin district.