Numerical simulation of the impact of urban canopies and anthropogenic emissions on heat island effect in an industrial area: A case study of Angul-Talcher region in India

Abstract

Changing urban land use dynamics and associated anthropogenic heat (AH) has increased warming over urban centres. This warming is associated with the Urban Heat Island (UHI) effect and is mainly studied in major cities worldwide. However, predominantly industrial regions can also experience heat island effect due to heat emissions from industrial infrastructure and associated activities. The current study examines the role of the urban morphology and anthropogenic heat over the Angul-Talcher region (industrial region) of Odisha state, India. The region is also referred to as India's highly polluted industrial cluster due to open cast mining and industries. In the present study, Weather Research and Forecast model (WRF) coupled with Single-Layer Urban Canopy Model (WRFUCM) has been modified to examine the impact of urban morphology and anthropogenic heat on the heat island effect over the region. The study refers modified version of WRFUCM as the WRFAH[Gridded] model, which incorporates anthropogenic heat from different industries with stack height information. It was found that the WRF model capabilities have improved in simulating surface meteorological variables such as temperature at 2 m, wind speed, and relative humidity with the inclusion of gridded AH. Urban canopies were estimated to bring in an increase of up to 0.77°C in local near-surface temperatures during daytime and up to 2.12°C during nighttime. AH emissions further increased temperatures by up to 0.32°C during daytime and 0.69°C during nighttime. Maximum heat island intensity with urban canopies is estimated to be 5.62°C which increases to 7.11°C with the inclusion of average AH released at canopy level. However, this has significantly improved to 5.88°C with inputs of industry-specific AH released at stack heights with the WRFAH[Gridded] model against observed maximum heat island intensity of 6.06°C. Overall, the influence of urban morphology was found to be higher than the influence of AH over the region at ground level, and the inclusion of gridded AH in the model showed improved performance for the heat island assessment.