辽宁省沙尘天气分析

以1971-2005年辽宁60个站沙尘天气资料为基础,从年代际变化、季节变化、空间分布特点等方面对浮尘、扬沙、沙尘暴、沙尘天气综合影响程度进行了统计分析。结果表明:辽宁的沙尘天气年代际变化明显,且多发生在春季(4月最多),沙尘天气主要在3月下旬到4月下旬出现在沈阳西北部、阜新以及朝阳北部地区。结合辽宁的气候、空间特点,从沙源、大风、不稳定层结3方面分析了辽宁沙尘天气的形成以及时空分布不均的原因,简要介绍了辽宁防沙的措施、效果以及辽宁省气象台沙尘暴短期预报方法。

Analysis on Dust Weather in Liaoning Province

Based on the dust weather data observed by 60 meteorological stations in Liaoning Province during the period from 1971 to 2005,in this paper the interdecadal and seasonal change,spatial distribution and impacts of dust weather including floating dust,blown sand,sandstorm and dusty weather in Liaoning Province are analyzed.The results are as follows:(1) Interdecadal change of dust weather in the province is significant,dust weather occurred frequently during the period from 1971 to 1984,it was significantly decreased in past 20 years except that in 2002,and it occurs mainly in spring because of the influence of weather system,landforms and vegetation coverage,especially in April;(2) The impact of dust weather is most serious in the region northwest from Shenyang,Fuxin and northern part of Chaoyang;(3) The external and local sand source areas of dust weather in the province are the Horqin Sandland in east Inner Mongolia,northern part of north China,desertified lands in west Liaoning Province,northwestern part and partial central part of Liaoning Province.Strong wind and unstable atmospheric stratification in spring are the important factors resulting in the occurrence of dust weather in Liaoning Province;(4) Frequent occurrence of dust weather in Liaoning Province is mainly caused by the rapid temperature increase,strong wind,low vegetation coverage and low soil moisture content in spring;(5) Occurrence of dust weather in Liaoning Province has been effectively decreased because of building up the shelterbelts and implementing the weather modification.