Thermal Infrared Images to Identify the Contribution of Surface Materials to the Canopy Layer Heat Island in Hot-Humid Urban Areas

Abstract

This study presents a combination technique of thermal infrared images captured by infrared camera and satellite thermal images retrieved from Landsat-8 OLI TIRS to identify the contribution of vertical and horizontal surface materials in two hot-humid street canyons with similar sky view factor and street orientation. The infrared camera captures surface temperature images of vertical and inclined surfaces of the street canyons. The images at horizontal scale are derived based on six land cover indices – i.e., Land Surface Temperature (LST), surface albedo, thermal emissivity, Normalized Different Vegetation Index (NDVI), Normalized Different Built Area Index (NDBI), Normalized Different Water Index (NDWI) – using an image processing technique conducted in ArcGIS. This study used two micro weather stations to measure microclimate conditions depicting the Canopy Layer Heat Island (CLHI) of the canyons at the same time. Despite the capability of the combined technique to identify the contribution of surface materials to the LST, different radiative and thermal properties of the surface materials insignificantly modified the CLHI.