基于Z指数的芦溪县干旱特征分析

根据江西省芦溪县1958~2013年逐月和逐年的降雨资料计算出Z干旱指数,并根据Z指数将干旱强度划分为7个等级,分析该地区的干旱特征.结果表明:芦溪县近56年来Z指数呈上升趋势,总体偏涝趋势且具有较明显连旱年的特征;从季节尺度长期变化特征来看,夏季发生干旱的频率最高,占32.1%,春季呈现偏旱发展的趋势,夏秋冬三季均表现出偏涝发展的态势,尤其夏季Z指数上升趋势较为显著;从干旱趋势突变分析结果可知,突变年份有1961、1963、1967、1969和1971年,1965年后只存在偏涝方向的发展趋势且在1997~2007年和2010年以及2012年达到显著性水平.

Analysis on drought characteristics of Luxi county based on Z index

To analyze the drought character in LuXi county of JiangXi province,seven levels was divided by the Z index,which had been calculated by monthly precipitation and annual precipitation data (1958-2013) in the areas.Results showed that:The annual Z index showed an increasing trend in the last 56 years.Overall,it was a tendency to flood,and had the obvious characteristic of continuous drought;according to seasonal difference of drought,the probability of drought,accounting for 32.1%,was the largest in summer;partial drying trend was showed in spring,and partial flood trend was showed in other three seasons,especially the Z index in summer increased remarkably;mann-Kendall test results showed that the sudden change years had been occured in 1961,1963,1967,1969 and 1971,partial flood trend had been only presented since the year of 1965,and the trend had become more significant in 1997~2007,2010 and 2012.