基于NPP-VIIRS夜间灯光数据和Landsat-8数据的城镇建筑用地提取方法改进——以广州市为例

Improvement of Urban Construction Land Extraction Method Based on NPP-VIIRS Nighttime Light Data and Landsat-8 Data:A Case Study of Guangzhou City

以广州市为例,将Landsat-8-OLS数据与NPP-VIIRS夜间灯光数据相结合提取城镇建筑用地,在常规的NDBI指数、ULI指数方法的基础上进行改进,以获得更加精确的城镇建筑用地信息。首先,利用NPP-VIIRS夜间灯光数据得到城镇建筑用地的大致分布范围,基于Landsat-8-OLS数据提取NDBI、NDVI指数;然后通过分析夜间灯光建筑用地范围、NDVI指数,NDBI指数三者的特性,分别对三者图像进行二值化、求交运算来提取城镇建筑用地;最后将提取结果与传统的NDBI指数、ULI指数方法的提取结果进行对比,利用Google Earth高空间分辨率影像数据进行精度验证。结果表明,结合NPP-VIIRS数据和Landsat-8-OLS数据的多指数提取相交运算,可有效剔除提取结果中包含的裸土信息,与NDBI等指数方法相比,能得到更高的精度。

Taking the city of Guangzhou as an example, the Landsat - 8 - OLS data and the NPP - VIIRS nighttime light data were combined to extract the urban construction land, and the conventional NDBI index and ULI index method were improved to obtain more accurate urban construction land information. First, the NPP - VIIRS night light data were used to obtain the approximate distribution range of urban construction land, and the NDBI index, NDVI index was extracted based on Landsat - 8 - OLS data. Then by analyzing the characteristics of nighttime construction range, NDVI index and NDBI index, the three images were binaries and the urban con- struetion land was extracted. The last, we compared the results of extraction with the traditional NDVI index, ULI index extraction re- sults, and use Google Earth high spatial resolution image data for precision verification. The results show that the multi - exponential extraction intersections of NPP - VIIRS data and Landsat - 8 - OLS data can effectively eliminate the bare soil information contained in the extracted results, and get higher precision than the traditional NDBI index method.