摘要
根据1961~2009年汉江上游安康市逐月降水资料,利用Z指数旱涝指标划分了7个旱涝等级,并对旱涝发生的时间演变规律及成因进行了初步分析。分析结果表明:Z指数能较好地反映本区的旱涝变化情况,近50年安康市由偏涝向偏旱发展,与降水量以4.9 mm/10 a的速率呈减少趋势一致。四季的Z指数变化趋势表现出明显不同,春、秋季略呈下降趋势,为干旱增强趋势;夏、冬季呈上升趋势,为洪涝增强趋势。在1982~1986年间,安康市发生了明显的降水趋势转型,春秋季降水减少,夏冬季降水增多。且从1998年之后,降水表现出波动大、不稳定的特征,四季Z指数年际间波动幅度都较大,旱涝灾害明显增多。进入21世纪以后,旱涝灾害发生频率明显增加。
Based on the data of the monthly precipitation in Ankang city located at the upper reaches of the Hanjiang River from 1961 to 2009,seven drought-flood grades were compartmentalized by Z-index.The temporal evolution law and causes of drought-waterlogging occurrence were analyzed.The results indicated that the Z-index could reflect the changeable features of drought-flood in Ankang city well.In the recent 50 years,Ankang city developed from partial waterlogging to partial drought,and it was in accordance with...
出处
《江西农业学报》
CAS
2011年第5期144-148,共5页
Acta Agriculturae Jiangxi
基金
国家自然科学基金重点项目(41030637)
中央高校基本科研业务费专项基金项目(GK201002015)
关键词
降水
Z指数
旱涝灾害
特征
安康市
Precipitation
Z-index
Drought and flood
Characteristics
Ankang
