基于Z指数的芦溪县干旱特征分析

Analysis on drought characteristics of Luxi county based on Z index

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.

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 pres- ented since the year of 1965 ,and the trend had become more significant in 1997 -2007,2010 and 2012.