应用国家气候中心下发的吉林省四平市5站的逐日降水资料对四平市进行旱涝等级划分,主要应用线性趋势法和小波分析法对其特征进行分析,根据旱涝指标Z指数对旱涝指数W指数进行运算.结果分析得出:W指数存在较弱的下降趋势,并且阶段性特征变化明显,W指数计算得出严重旱年与降水距平百分率有很好的对应关系;54年四季旱涝年数差异较大,各季存在旱涝交替、连旱或连涝的特征;年W指数以3.68· 10a-1的速度递减,春季和冬季W旱涝指数以3.89· 10a-1和10.183·10a-1的速率增加,均通过0.05水平的显著性检验,呈现增加趋势,夏季和秋季W旱涝指数呈现递减趋势.从小波分析结果得出各季节震荡周期不同并且特征显著.%Based on the calculation of the drought-flood index (Z index,W index) with the daily precipitation data of 5 meterological stations,the variation of drought-flood in Siping region was analyzed by the linear trend method and wavelet analysis method.The restdts showed that the W index data was in a weak downward trend in the Siping during the past 54 years,and exhibited altemating drought and flooding.The extreme drought year of W index corresponded to the precipitation anomaly year.These two had consistency and W index might well reflect the flood/drought rules of Siping region.The &ought parameter W tends to decreased at a rate of 3.68· 10a-1,while it tends to increased significantly at the rate of 3.89· 10a-1 in spring,and 10.183· 10a-1 in winter.Each season has a different oscillation period and distinguished feature according to the result of the wavelet analysis method.
展开▼
