基于Z指数的都昌县干旱特征分析

Analysis on Drought Characteristics of Duchang County Based on Z Index

根据江西省都昌县1953—2012年逐日降雨资料计算各年度及各季节Z干旱指数,分析该地区的干旱特征,并运用Mann-kendall检验法对年降雨Z指数进行趋势及突变检验。结果表明:都昌县60 a来Z指数总体呈现下降的趋势,表现为涝转旱发展态势且具有较明显连旱年的特征;从季节性干旱特征来看,春夏冬3季的Z指数都表现为下降的趋势,且形成春旱趋势更显著;从干旱趋势突变分析看,旱涝突变的年份为1956年,且在1956—1970年、1978—1998年、2006—2012年干旱加重趋势达到显著性水平。

To analyze the drought character in Duchang county of Jiangxi province,the Z index of each year and season had been calculated by daily rainfall data(1953-2012)in the areas,and Mann-Kendall test was used to test the trend and mutation of annual rainfall Z index.Results showed that:The annual Z index showed a downward trend in the last 60 years.Overall,it showed the development trend from waterlogging to drought and had the characteristics of continuous drought;According to seasonal difference of drought,The Z index showed a downward trend in spring,summer and winter,and the trend of spring drought was more significant;Mann-Kendall test showed that the sudden change years had been occurred in 1956,Moreover,the drought aggravation trend reached a significant level from 1956 to 1970,1978 to 1998 and 2006 to 2012.