Urban Atmospheric Vulnerability Assessment of Kano Metropolis using Remote Sensing and Geospatial Techniques
M. N. Pius *
UN-Habitat, Abuja, Nigeria.
A. C. Salihu
Department of Meteorology and Climate Change, African Aviation and Aerospace University, Abuja, Nigeria.
R. J. Jacob
Confluence University of Science and Technology, Osara, Kogi State, Nigeria.
A. A. Shariason
Department of Geography and Environmental Management, ABU Zaria, Zaria, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Urban atmospheric vulnerability is increasing in rapidly growing cities where heat exposure, dust-related atmospheric pressure, vegetation loss, and built-up expansion overlap. This study assessed dust–heat atmospheric vulnerability across Kano Metropolis, Nigeria, using a remote sensing and geospatial index approach. The Dust–Heat Atmospheric Vulnerability Index (DHAVI) was developed for eight metropolitan Local Government Areas: Dala, Fagge, Gwale, Kano Municipal, Kumbotso, Nasarawa, Tarauni and Ungogo. The index integrated satellite-derived atmospheric indicators, land surface temperature, vegetation condition, built-up pressure, population exposure, road density, market pressure, industrial/commercial activity, nighttime activity and wind-dispersion context. Atmospheric indicators were extracted for the dust season from 1 November 2023 to 31 March 2024, while surface heat indicators were extracted for the hot-dry season from 1 March to 31 May 2024. The results showed clear spatial inequality in atmospheric vulnerability. Gwale recorded the highest DHAVI score of 0.602 and was classified as High vulnerability. Tarauni ranked second with 0.520, followed by Dala with 0.516 and Nasarawa with 0.501. Kano Municipal, Kumbotso and Fagge were classified as Moderate, while Ungogo recorded the lowest score of 0.240. The findings showed that vulnerability was compound rather than driven by a single factor. Kumbotso recorded the highest mean land surface temperature at 49.280°C, while Ungogo recorded the highest AOD at 0.576, yet neither was ranked highest overall. Gwale ranked first because atmospheric burden, NO2, CO, road pressure, industrial/commercial activity, nighttime activity and population exposure overlapped. The study concludes that DHAVI is useful for spatial prioritisation and recommends immediate ground monitoring and LGA-specific atmospheric-risk planning in Gwale, Tarauni, Dala and Nasarawa.
Keywords: Dust–Heat Atmospheric Vulnerability Index, atmospheric vulnerability, aerosol optical depth, urban heat, remote sensing, geospatial analysis, land surface temperature, population exposure, urban activity pressure, Kano Metropolis