Monitoring the Urban Areas in Urban Heat Island (UHI) and Modeling the Probable Locations for Urban Expansion: The Case Review of Karachi

Abstract

Background: Globally, urban heat island (UHI) is a common phenomenon which shows high temperature difference between urban and rural areas. The temperature difference is known to be caused by massive densely populated cities as related to rural zones.

Objectives: The main objectives of this study are to analyze UHI and modeling for Karachi. The research of the objectives sub-divided to develop a digital elevation model, slope, population density, built-up land, impervious surface and water, land surface temperature, vegetation cover, land surface temperature, soil moisture index, water body and land use/land cover. These parameters helped to extract the overall urban expansion model.

Methods: The methodology uses RS/GIS techniques and data of Landsat 8 OLI/TIRS and SRTM (DEM) satellite images. Similarly, ERDAS IMAGINE 9.2 and ArcGIS 10.3.1 softwares were used for data analysis.

Results: The results show that Urban Heat Island (UHI) is growing rapidly in the city, particularly with increasing settlements. This study also shows urban expansion potential of Karachi city.

Conclusions: The results can help in developing strategies for future urban expansion and growth of Karachi, and potential options for decreasing UHI. The results concluded that the UHI cannot be decreased without taking effective decisions and proper implementation keeping in view the rapidly increasing population.