基于AWTP指数的浙江省干旱规律时空分析

利用浙江省51个气象站1960-2009年的50 a逐日降水资料,基于降水的平均等待时间(AWTP)指数,采用小波分析和克里金空间插值方法对浙江省干旱时空特性进行分析。结果表明,浙江省的干旱随时间增加有加剧趋势。在50 a中,1979年干旱程度最强,相当干期值最大,达到52 d。在趋势变化上还同时叠加着明显的年际和年代际变化。浙江省干旱存在3 a左右的主周期;另外浙江省的干旱具有明显的区域性,干旱程度由南向北递增。嘉兴的平湖市及浙西金华周围内陆丘陵盆地发生干旱比其他地区更明显,其次是杭州市西部、温州市及台州市温岭等东南沿海山地丘陵地区,中东部的宁波市和绍兴市、西北部的湖州市以及浙江西南部等地区发生干旱程度较轻。

Temporal and Spatial Analysis on Drought Events over Zhejiang Province Based on AWTP Index

Using 51 meteorological stations’daily rainfall data from 1960 to 2009 over Zhejiang Province and basing on the index of averaged waiting time for precipitation(AWTP) and wavelet analysis and Kriging spatial interpolation method to analyze temporal and spatial characteristics of droughts in Zhejiang Province.The results show that the trend of drought is increasing in recent years;in 50 years,the maximum value of equivalent dry period reaches 52 days in 1979;there is a clear inter-annual and decadal variation in the trend of change;there are three years of primary cycle on Zhejiang Province’s drought.At the same time it shows that Zhejiang has a significant regional drought,which increases from south to north;the drought of Pinghu and Jinhua of western Zhejiang is more evident than the other regions;west Hangzhou,Wenzhou,Taizhou and partial southern places come the second place;that of Ningbo,Shaoxing and Huzhou is the lightest.