Estimation of Outdoor Thermal Comfort by Integrating Landsat derived LULC to WRF-UCM Model over a Metropolitan City of India

Cities are experiencing drastic changes in land use and land cover (LULC), leading to increased thermal discomfort in urban and surrounding areas, which plays an important role in understanding the impact on public health. Sustainable cities aim to incorporate strategies that effectively manage changes in the regions of various degrees of outdoor thermal comfort, enhancing overall urban living conditions. Accurate representation of the spatial distribution of LULC in mesoscale models is essential for improved simulations of urban meteorological parameters and subsequent estimation of outdoor thermal comfort. In this study, an attempt has been made to reconstruct LULC along with surface parameters such as GVF and albedo using Landsat 8 satellite imageries. These data are compared with existing ISRO LULC data over a metropolitan city, Hyderabad (17.3850° N, 78.4867° E) during 2019. Upon validating with Google Earth Maps, the reconstructed LULC exhibits significant improvement in representing moderate vegetation, urban forest, and bare lands compared to ISRO LULC. A high-resolution mesoscale model WRF-UCM has been employed to simulate meteorological parameters as well as estimate the Universal Thermal Climate Index (UTCI) during the summer and winter seasons of 2019, using these two LULC data sets and validated with meteorological observations and satellite products. The reconstructed LULC reveals a significant rise in air temperature by 1 ℃, 4 ℃ in Land Surface temperature, and UTCI by 2 ℃ over the dense urban region. The results reveal significant improvement in the assessment of LST and the intensity of outdoor thermal comfort. The presented study emphasizes the importance of accurately representing LULC in estimating outdoor thermal comfort and implementing mitigation strategies to improve the sustainability of the cities in terms of comfort and health.