Blue colour-coated steel roofs(BCCSRs)offer a lightweight and economical option to concrete and other cladding in buildings,but they are also controversial for altering the surface energy budget and water cycle.Obtain...Blue colour-coated steel roofs(BCCSRs)offer a lightweight and economical option to concrete and other cladding in buildings,but they are also controversial for altering the surface energy budget and water cycle.Obtaining spatial information about BCCSRs is crucial for exploring the environmental impacts of man-made landscapes.However,existing methods are not always effective due to the variety of BCCSR types and background conditions.To overcome these limitations,we proposed a new index(called BCCSI)based on Sentinel-2 multispectral images to map the commonly used BCCSRs.Five typical study areas were chosen worldwide to develop and validate the BCcSl.Based on spectral analysis,we constructed the BCCSl using the blue,red,green,and shortwave infrared 2(SWIR2)bands to highlight the BCCSR while suppressing the background condition.Compared with five existing indices,the BCCSl was effective in the visual evaluation,separability analysis and BCCSR mapping.Moreover,the BCCSI achieved similar accuracy to the supervised classifier while avoiding the time-consuming and laborious effort of sample collection.Furthermore,the BCCSl showed its applicability in medium-resolution satellite data,such as Landsat-8 imagery.Thus,the proposed BCCSI provides a viable scheme for global BCCSR mapping and analysis.展开更多
基金funded by the National Natural Science Foundation of China(grant number 42192581)Open Fund of State Key Laboratory of Remote Sensing Science and Beijing Engineering Research Center for Global Land Remote Sensing Products(grant number 12800-310430005).
文摘Blue colour-coated steel roofs(BCCSRs)offer a lightweight and economical option to concrete and other cladding in buildings,but they are also controversial for altering the surface energy budget and water cycle.Obtaining spatial information about BCCSRs is crucial for exploring the environmental impacts of man-made landscapes.However,existing methods are not always effective due to the variety of BCCSR types and background conditions.To overcome these limitations,we proposed a new index(called BCCSI)based on Sentinel-2 multispectral images to map the commonly used BCCSRs.Five typical study areas were chosen worldwide to develop and validate the BCcSl.Based on spectral analysis,we constructed the BCCSl using the blue,red,green,and shortwave infrared 2(SWIR2)bands to highlight the BCCSR while suppressing the background condition.Compared with five existing indices,the BCCSl was effective in the visual evaluation,separability analysis and BCCSR mapping.Moreover,the BCCSI achieved similar accuracy to the supervised classifier while avoiding the time-consuming and laborious effort of sample collection.Furthermore,the BCCSl showed its applicability in medium-resolution satellite data,such as Landsat-8 imagery.Thus,the proposed BCCSI provides a viable scheme for global BCCSR mapping and analysis.
