贵阳市AOD遥感反演及其与土地利用类型的耦合关系

Remote sensing retrieval of AOD and coupling relationship to land use in Guiyang

传统的大气监测方法难以满足宏观、实时、动态的监测需求,应用高分辨率遥感影像进行区域大气质量状况监测手段逐渐备受关注。基于Landsat 8影像数据,运用暗像元法,通过"6S"辐射传输模型构建查找表,建立蓝、红波段地表反射率、表观反射率与气溶胶光学厚度(Aerosol Optical Depth,AOD)之间的关系,获取贵阳市30 m分辨率的AOD分布,分析贵阳市AOD空间分布特征及与土地利用的耦合关系。结果表明:1)基于遥感手段反演的AOD与地面监测数据一致性较好,与PM2. 5的相关性最高,贵阳市AOD最大值为0. 95,最小值为0. 23,均值为0. 63; 2)贵阳市云岩区的AOD均值最大,开阳县最小,AOD呈现出"南高北低"的分布格局; 3) AOD均值最大的土地利用类型是建设用地,为0. 73,最小的土地类型是林地,为0. 53; 4)将贵阳市AOD分为高值区、较高值区、较低值区、低值区4个等级,建设用地与水体在高值区面积比重明显大于在其它AOD等级的比重,林地在高值区的比重明显小于在其它AOD分区的比重,冬季耕地、草地在各区间分布比重差异较小。针对贵阳市气溶胶分布状况,提出大气环境保护的相关建议与对策。

The traditional atmospheric monitoring methods are difficult to meet the needs of macroscopic, real-time and dynamic monitoring. And application of high-resolution remote sensing images to regional air quality methods has attracted increasing attention. Based on Landsat 8 image, choicing dark pixels method and running the ＂6S＂ model to build a lookup table was to set up the relationship of the surface reflectivity-apparent reflectance and AOD （Aerosol Optical the Depth） and to obtain the retrieval of AOD at a spatial resolution of 30 m over Guiyang, analyzing the coupling relationship of between AOD spatial distribution characteristics and the land use types. The results show that： 1） Based on the AOD of remote sensing method has good consistency with ground monitoring data, and has the highest correlation with PM 2.5 .The maximum value of AOD is 0.95,and the minimum value is 0.23, with the average value of 0.63; 2） The average value of AOD in Yunyan district is the largest, while the smallest in Kaiyang county. The AOD values shows the distribution pattern of “south high and north low”;3） The land use type with the highest AOD average value is 0.73 for construction land, while the smallest type is 0.53 for forest; 4） Divide AOD into four categories： highest value area, high value area, lower value area and lowest value area. The proportion of construction land and water of the highest value area is significantly larger than other AOD levels. The proportion of forest land of the highest value area is significantly smaller than other AOD areas. The distribution of grassland in each interval is small. Finally, in view of the aerosol distribution in Guiyang, we also provide some suggestions and countermeasures for atmospheric environmental protection.