内蒙古作物生长季降水资源空间分布及月尺度旱情特征分析

The distribution of precipitation during crop growth season and the monthly drought characteristics in Inner Mongolia

研究内蒙古地区生长季内降水资源和旱情分布特征,对于该区合理布局农牧业、充分利用水资源以实现粮牧稳产具有重要的科学意义。文中利用内蒙古自治区46个气象站点1961-2010年逐日气温、降水量数据,分析了内蒙古地区5～9月降水资源时空分布规律,并基于干旱指数（K）从月尺度上研究了旱情分布特征。研究表明：1）内蒙古地区生长季降水资源不足且空间分布不均匀,降水量（平均为255.0mm）自西向东递增。近50年降水有减少的趋势,降水变率为25.3%,与降水量成反比。2）生长季重旱以上的区域面积占自治区面积的37.5%。5月份旱情最严重,基本为＂十年十旱＂。3）内蒙古地区旱情等级呈经向分布特点,西部地区干旱程度重于东部地区。

The distribution characteristics of precipitation resources and drought during the growing season in Inner Mongolia need to be studied,which have important scientific significance for the rational distribution of agricultural and livestock and full utilization of water resources to achieve stable yield.Based on the 1961-2010ground surface meteorological data（daily precipitation and average temperature） from 46 meteorological stations in Inner Mongolia,we analyzed the temporal and spatial distribution of precipitation from May to September in recent 50 years in Inner Mongolia,and studied the distribution characteristics of drought in monthly scale by using the drought index（K）.It showed that： 1） The precipitation during crop growth season,whose spatial distribution was uneven,was insufficient and increased gradually from west to east,with an average of 255.0mm.In 1961-2010,the precipitation was trended to be decreased by-4.5mm/10a,whose variability was 25.3%,inversely proportional to precipitation.2） Inner Mongolia had varying degrees of drought during the growth season,and the extreme drought area accounted for 75.5% of all.May was the driest month,and extreme drought happened every year.3） The drought level was distributed by longitude,the western region was worse than the eastern region.