地表土壤湿度和植被状况的监测及其与沙尘暴发生的关系探讨

Study on the Relationship between Occurring Time of Sandstorm and Soil Moisture as well as Vegetation Cover

利用NOAA/AVHRR数据,采用单时相乘积法计算土壤湿度,采用NDVI指示地表状况,利用地表土壤相对湿度旬平均值、NDIV旬平均值、风速以及三者的综合值与实测的沙尘暴旬数据,定性和定量分析了中国北方地区土壤湿度、植被覆盖、风速与沙尘暴发生的关系,结果表明风速是影响沙尘暴发生的关键因素,与沙尘暴发生成正比;土壤相对湿度与地面植被在一定程度上影响了沙尘暴的发生,与沙尘暴的发生成反比;由平均风速、土壤相对湿度和NDVI组成的综合因子与沙尘暴发生次数及能见度的相关性高于风速与后二者的相关性,因此综合因子具有指示和监测沙尘暴发生的潜力。

With NOAA/AVHRR data, the single phase product method is used to estimate the soil moisture of surface cover, and NDVI is used to estimate vegetation cover, and further more the relationship between percentage of soil moisture, vegetation cover and time of sandstorm in north of China was analyzed. The results show that wind speed is the key factor which plays an important role on the sandstorm. The occurring frequency of sandstorm goes up with the rise of wind speed. But soil moisture and vegetation cover plays a negative effect on the frequency and intensity of sandstorm.