宁夏特强沙尘暴气候背景及其成灾规律研究

沙尘暴是宁夏主要的灾害性天气之一,每年强及特强沙尘暴给当地国民经济造成巨大损失,并导致中部干旱带生态环境进一步恶化,加快了荒漠化进程。文章从沙尘暴发生的机理和形成机制出发,通过对历史气象资料及沙尘暴灾情资料的综合分析研究,初步形成宁夏沙尘暴天气运动、成灾规律的概念模型,并对宁夏沙尘暴灾害进行区划。

Climatic Background and Disaster Characteristics of Severe Sand Storms in Ningxia

The movement and characteristics of sand storms are analyzed by using the historical meteorological data along with sand storm disaster in Ningxia region.The results show that times of severe sand storms in Ningxia have been increasing in recent years.Following factors are the climatic background resulting in severe sand storms:continuous drought in seasons prior to sand storms,soil water deficiency;bitter cold winter before sand storms,deeper frozen earth,loose surface soil after thawing;large longitudinal grads of East-Asia circulation,and strong wind resulting from the severe southern cold air.The damage of sand storms in Ningxia became severer and severer in recent years,and the characteristics of the disaster are spatially heterogeneous.Strong wind dominantly characterizes sand storms in the irrigated regions of north Ningxia;Wind erosion,sand encroachment strong wind,and casualties due to low visibility are typical features in the middle drought belt of Ningxia;Catastrophes of other irrigated regions are mainly wind frost.Sand storm disasters of Ningxia are spatially regionalized according to their features.