河套地区暴雨的地域性特点及灾情分析

Regional Characteristics and Disaster Analysis on Rainstorms in Hetao

选取河套地区87个气象站1961-2010年逐日降水量资料,采用线性趋势分析、Mann-Kendall检验以及合成分析等方法,分析了河套地区暴雨日数的时空分布特征及其气候变化规律。结果表明:河套地区暴雨日数呈明显的"东南多、西北少"空间分布特征,暴雨主要出现在河套地区东南部;暴雨以单站暴雨为主,同日1个站出现暴雨占暴雨总数的49.5%,同日10站以上出现暴雨主要是在河南、山西、陕西三省交界和山西、陕西、内蒙古三省交界地区;7-8月份暴雨日数占暴雨总日数的74.1%;局地性暴雨平均每年出现26.3 d、区域性暴雨平均每年出现4.4 d,暴雨总日数、局地性暴雨日数和区域性暴雨日数均呈减少趋势,并存在明显的波动性年际变化,但均未发生突变现象;河套地区暴雨具有雨日少、雨量大,局地性暴雨多、区域性暴雨少的分布特点,暴雨常常造成人员伤亡、农作物受灾、牲畜死亡、房屋倒塌、道路与通信设施毁损,因灾经济损失十分巨大。

Based on daily precipitation data from 87 meteorological stations in Hetao during 19612010,and by using methods as linear trend analysis,Mann-Kendall test,composite analysis etc.,temporal-spatial distribution characteristics and the rules of climate changes of the rainstorm days in Hetao are analyzed. Results show that the rainstorm days of Hetao are obviously more in the southeast and less in the northwest,and appear mainly in the southeast. Most of the rainstorm days appear in the single stations,and the rainstorm days of 49. 5% appear in the same day,and the rainstorm days of 74. 1% appeared in July and August. The local rainstorm days are 26. 3 days and the regional rainstorm days are 4. 4 days in every annual,the rainstorm days,local rainstorm days and regional rainstorm days all display reduced tendency in Hetao,and have obvious inter-annual fluctuating variability,but have no abrupt change. The rainstorm often cause casualties,crops disaster,death of livestock,collapse of the housing,roads and communication facilities are damaged,and the economic losses are great.