锡盟沙尘暴的时空分布及其与气候因子的关系

Spatiotemporal distribution of sand-dust storm in Xilingol League and its correlation with climate factors

利用内蒙古锡林郭勒盟15个气象站30年(1971-2000年)的沙尘暴观测资料,分析了沙尘暴发生日数的时空分布以及气候因子对沙尘暴日数的影响。结果表明,锡盟的中西部是沙尘暴的易发区,其中苏尼特右旗及朱日和是沙尘暴的高值区;从单站的沙尘暴日数来看,沙尘暴的发生时间有明显的日变化和季节差异,30年间除朱日和站沙尘暴年际变化趋势不明显外,其它两站的沙尘暴日数均有显著的下降趋势;沙尘暴的年代际变化也呈减少的趋势。大风对沙尘暴发生次数的影响最为显著,单站的相关系数在0.60以上(通过0.05显著性检验);平均气温日较差与沙尘暴日数也呈显著正相关;其中锡林浩特站的年均气温及冬春季平均气温与沙尘暴日数有显著负相关;降水量对沙尘暴的发生次数有一定的影响,尤其是前期降水量与次年沙尘暴的发生有较好的负相关。

Based on the observed sand-dust storm data and meteorological records from 15 meteorological observational stations in Xilingol League of Inner Mongolia for 30 years（ 1971 -2000）, the temporal and spatial variation characteristics of sand-dust storm are statistically analyzed. The influence of climate factors on the sand-dust storm events is quantitatively studied. The result shows that the central-western part of Xilingol League is the most frequent hit region on spatial distribution, especially in Suniteqi and Zhurihe as the two high value regions. According to the sand-dust storm days of individual stations, there is an obvious daily variation and seasonal differences. The decadal characteristic of sand-dust storm days appears an obvious downward trend during the past 30years, except for Zhurihe station. Correlation analysis shows that wind is a key factor in the occurrence of sand-dust storm in the study area, and the correlation coefficient between sand-dust storm days and strong wind is above 0.60 （ correlation is significant at the 0.05 level ）. Significant positive correlation between daily range of air temperature and days with sand-dust storm is also found. There are significant negative correlation between the number of sand-dust storm days and mean annual temperature, mean winter temperature and mean spring temperature only in Xilinhaote station. Increase of precipitation over the source areas of dust or so might restrain the development of sand-dust storm So the total precipitation especially the early stage ones are much more important.