Assessment of Urban Heat Island and Spatiotemporal Landscape Transformation In Three Cities Of Sindh, Pakistan

Abstract

Urban Heat Island is considered one of the main causes of urbanization. It impacts the overall livability of a city. It is mainly due to the biophysical changes of the land surface due to urbanization. This study is based on three cities of Sindh namely: Hyderabad, Sukkur and Larkana. To study the UHI effects, a Land Surface Temperature algorithm is used. Land use land cover changes are identified by using Maximum likelihood classification. This study reveals that there is a major change in urban development in Hyderabad and Sukkur that is (82 to 97) Km2 and (18 to 25.7) Km2, respectively. While, in Larkana, minimal urban development is observed (33 to 34.6) Km2. Similarly, massive changes in vegetation are also observed in Sukkur and Larkana from 1990 to 2020 that are (90 to 161) Km2 and (82 to 331) Km2, respectively. Increase in vegetation is majorly due to the agricultural activities mainly occurring in different seasons. This study confirms that the LST has a strong negative correlation with NDVI because with increasing vegetation the LST is reduced. The findings also reveal that the major source of increased surface temperature is not only urban areas but the bare lands. The study finds that the skin temperature of the ground drops at least 3-5 degrees in the areas having a water body or any vegetation. This research highlights the importance of the inclusion of green strategies in better and effective urban planning to maintain a healthy urban environment.