【摘要】 以归一化差值植被指数(Normalized Difference Vegetation Index,NDVI)为指标分析了我国1981年到1998年期间植被覆盖变化情况,给出了植被急剧减少产生新沙源的实例。通过对1998年4月强沙尘暴的分析,指出影响沙尘暴产生和运移的因素除了地形、风速、风向、大气稳定度外,当地植被覆盖和土壤因素也是关键因素之一。并通过对植被覆盖度(NDVI)与浮尘指数(Aerosol Index)进行定量分析,发现二者之间存在明显的负相关关系,表明植被的存在可以从一定程度上抑制浮尘现象的产生。因此,在沙尘运移路径上,采取封山封荒,植树种草,增加植被覆盖度以固结当地土壤和泥沙的措施,可以在一定程度上抑制沙尘暴灾害的发生。更多还原

【Abstract】 The change of vegetation cover from 1981 to 1998 in China was analyzed using normalized difference vegetation index as the indicator,then the situation that new sand source formation caused by the drastic reduction of vegetation cover was presented.Local vegetation cover and soil factor are the key factors affecting the generation and migration of sandstorm besides terrain,wind speed and direction,atmospheric stability by the analysis of sandstorm in April 1998.And the quantitative analysis of NDVI and Aerosol Index showed there is a negative correlation between them,and the presence of vegetation can inhibit the generation of dust phenomena to some extent.Therefore,measures like mountain closure and trees planting can be taken to improve the vegetation cover and the soil consolidation,which help decrease the sandstorm to some extent.更多还原