锡林郭勒地区降水时空分布特征及变化趋势

通过对锡林郭勒地区降水变化特征的探讨，为水资源的开发利用及防洪和流域治理规划提供理论依据。根据锡林郭勒地区15个气象站1960-2009年基本气象观测资料，运用一元线性回归、线性倾向估计、相关分析等数理统计方法，分析了近50年降水时空分布特征及变化趋势。结果表明，降水量整体分布不均匀，局地差异大，大体由东南部向西北部递减。变化趋势呈不明显的减少趋势，变化速率为-3.5 mm/10 a。降水日数有减少的趋势。四季降水量春冬季略有增加趋势，变化速率分别为1.1 mm/10 a、0.1 mm/10 a，夏秋季略有减少趋势，变化速率分别为-4.1 mm/10 a、-0.7 mm/10 a，夏季降水量的减少，会造成该地区旱灾频繁，对牧草及农作物生长和成熟十分不利。

The Trend and the Temporal-spatial Distribution Features of Precipitation in Xilingol Area

The characteristics of precipitation in Xilingol were studied to provide theories for the water exploit, flood prevention and drainage area management. According to the meteorological observation of 15 stations during the period of 1960-2009 in Xilingol, using statistical methods such as unitary linear regression （ULR）, linear trend analysis and correlation analysis, the trend and temporal-spatial distribution of precipitation in the past 50 years were analyzed. The results showed that precipitation was unevenly distributed and widely varied among different areas, and exhibited a decreasing trend from southeast to northwest spatially. The yearly precipitation also showed an insignificant decreasing trend with a rate of-3.5 mm per 10 years. The number of days with precipitation had a decreasing trend. Spring and winter precipitation showed an increasing trend, with a rate of 1.1 mm per 10 years, and 0.1 mm per 10 years, respectively. In summer and autumn, however, precipitation showed a decreasing trend, with a rate of-4.1 mm per 10 years, and-0.7 mm per 10 years, respectively. The decreasing trend in summer was the most significant.