中国西北地区沙尘天气的时空位移特征

 沙尘暴是一种灾害性的天气,具有明显的时空分布特征。中国西北地区风大、沙多,是沙尘天气和沙尘暴的易发地区。通过GIS技术,利用中国西北5省区和内蒙古西北部158个气象站的沙尘资料,对中国西北地区近45 a总沙尘天气（包括浮尘、扬沙）和沙尘暴的时空变化特征进行分析,初步探讨了不同时间、不同区域的沙尘天气和沙尘暴影响范围。结果表明,无论是沙尘天气还是沙尘暴,都具有明显的时空分布特征;各季节沙尘天气和沙尘暴的影响范围和发生程度不同,总的来说,中国西北地区以春季最为多发,约占全年总数的1/2,依次为夏季、冬季和秋季;不同的季节,不同程度沙尘天气和沙尘暴的影响范围不同,春季是低度易发生区和中度易发生区面积较大时期;夏秋冬是低度易发生区和不发生区面积较大的时期。上述分析表明,沙尘天气和沙尘暴发生的时间和空间都存在差异性。

Temporal and Spatial Characteristics of Dust Events in Northwest China

Sandstorm is a disastrous weather type and has obvious spatial-temporal characteristics.There is large area of sand-dust resource and strong wind in northwest China,so dust events frequently take place.Using sand event data from 158 weather stations in northwest China,we analyzed the spatial-temporal distribution of dust and sandstorm events based on GIS technology.Result indicated that dust events and sandstorm events had obviously seasonal variation,and the development area and degree of dust events and sandstorm were different in four seasons.The dust events and sandstorm took place most frequently in spring in northwest China,accounting for almost 50% of the total times.The affecting ranges of different degrees of dust or sandstorm events were different in four seasons.The range with light and middle frequency is relatively large in spring,and that with light and very light frequency is relatively large in summer,autumn and winter.