宁夏盐池沙尘暴特征分析

Characteristics of Sand\|dust Storm in Yanchi County, Ningxia Province

对盐池气象站1961—2000年逐月气象数据进行了较为详细地分析,结果表明,干旱多风的气候特征在时间搭配上的一致性,是沙尘暴发生的主要直接原因;沙尘暴频率与降水量和大风日数显著相关,降水量对沙尘暴的影响滞后1～3个月。从较长时间序列看,影响沙尘暴发生的自然因子(以降水和大风为代表)的作用在逐渐下降,而人为因素的权重在不断加强,反映出生态环境的不断恶化;沙尘暴逐年序列的2～8a周期,是受到厄尔尼诺影响的结果。

Sand\|dust storms are an unexpected result of the desertification process. Climate change (regional and global) and local human activities combine as the primary cause of the frequent storms in northern China. It is important to study the relationship between sand\|dust storms and climate factors to gain a deeper understanding of storm patterns. \;Yanchi County, in Ningxia Autonomous Region is one of the fastest developing regions of sandy desertification in northern China. A detailed analysis of monthly meteorological data from 1961 to 2000 has been undertaken for this region. The results show that drought and wind are the direct causes of sand\|dust storms. The frequency of the storms is evidently related to lack of precipitation and days of strong wind. Rainfall at intervals of 1～3 months will significantly retard the propagation of storms. The influence of human action is slowly over\|weighing natural factors (rainfall and wind) as the main cause of storms and this indicates a worsening local ecology. The 2～8 year cycle of sand\|dust storms is also influenced by El Nino.