晋西北地区气候变化及其对土地沙漠化的影响

利用晋西北5个代表站近50 a逐月的气温、降水资料,建立了年和冬、夏半年的平均气温、降水序列,分析了晋西北近50 a来气温、降水变化特征。结果表明,晋西北总的气候变化存在暖干化趋势,年和冬、夏半年平均气温变化倾向率分别为0.202 ℃/(10a)、0.2 ℃/(10a)和0.132 ℃/(10a)；夏半年气候变暖缓慢且具有阶段性特点；年和冬、夏半年降水变化倾向率分别为-16.68 mm/(10a)、0.404 mm/(10a)和-14.95 mm/(10a)；年降水的减少主要由夏半年降水的减少引起,冬半年降水有增多的迹象；夏半年降水减少,减弱了流水对表层土壤的冲刷,冬半年降水增多,一定程度上减缓了土地沙漠化过程。

Climate Change and Its Impact on Land Desertification in Northwestern Shanxi Province

Based on data of monthly temperature and precipitation from 5 representative meteorological stations in northwestern Shanxi province during the period of 1957—2006, the series of average temperature and precipitation of the whole year, winter half year and summer half year were established, and the changing features of temperature and precipitation and their impact on land desertification were analyzed. Results showed that climate tends to become warmer and arider in the area. The linear trend rates of average temperature for the whole year, winter half year and summer half year were 0.202 ℃/(10a), 0.2 ℃/(10a) and 0.132 ℃/(10a), respectively; It had gradual and periodical features for average temperature in the summer half year. The linear trend rates of precipitation for the whole year, winter half year and summer half year were -16.68 mm/(10a), 0.404 mm/(10a) and -14.95 mm/(10a), respectively. The reduction of annual precipitation resulted mainly from reduction of precipitation in summer; precipitation in winter increased in comparison with that in summer. The condition of precipitation reduces in summer and increases in winter can certainly slow the process of land desertification.