Appraisal of Urban Heat Island over Gujranwala and its Environmental Impact Assessment using Satellite Imagery (1995-2016).

Syeda Areeba Gillani,Sarwar Ali,Saif-ul- Rehman,Hafiz Haroon Ahmad,Zubair Ateeq,Atif Ahmad,Usama Junaid,Abdul Rehman

doi:10.33411/ijist/2019010101

Abstract

Rapid urbanization and concretization are the main sources of formation and existence of Urban Heat Island (UHI). Due to high concentration of pollutants in urban environments, the residents are exposed to unexpected health issues. This study aims at delineating the temporal variations in the spatial extent of UHI over Gujranwala using Landsat thermal imagery. It also aims at determining the variations in pollutant concentration in the atmosphere due to vehicle’s tailpipe emissions and fossil fuel burning by industrial plants. We used various indices e.g., NDVI, NDBI, NDWI and land surface temperature calculations to investigate spatio-temporal variations in urban growth patterns and their impacts on the UHI. The results show that the UHI enlarged in all direction specially in the north west during the study period which is similar to urban growth trends. There also exist positive correlation between industrial and vehicle’s discharge with pollutant’s concentration in atmosphere. Remote sensing tools proved elegant in trend mapping and analysis.

Highlights

The recent migration trends of masses toward developed cities in search of basic needs of life is very common around the world
It is the main reason of extensive urbanization [1] which has transformed the metropolitan areas into heat islands [2]and this phenomenon is termed as Urban Heat Island (UHI) [3]
Normalized Difference Vegetation Index (NDVI) is an important indicator commonly used to map the spatial extent of vegetation existing in an area

Summary

Introduction

The recent migration trends of masses toward developed cities in search of basic needs of life is very common around the world. It is the main reason of extensive urbanization [1] which has transformed the metropolitan areas into heat islands [2]and this phenomenon is termed as Urban Heat Island (UHI) [3]. The speedy urbanization has enhanced the anthropogenic activities that have led to the development of urban microclimates. Urban heat islands are of two types: 1) Atmosphere heat island 2) Surface heat island. The atmospheric heat island is further subdivided in two types: 1) Urban canopy layer; and 2) Urban boundary layer

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