Urban Planning Mitigation Trajectories for Urban Heat Island (UHI) A Case Study of Guntur, Andhra Pradesh, India

Abstract

Abstract

Global radiation related solair-temperature directly influences Urban Heat Islands (UHI) as the built environments and surrounding atmosphere cause increase in urban solair temperatures, the resulting temperature completely depends on the thermal properties of the exposed materials. Urban heat islands can lead to deterioration of flora and fauna, elevation of ground level ozone, health disorders and increase in building energy consumptions. The study area of Guntur region which is susceptible to high radiation and temperature has been studied with respect to Urban Heat Island through Landsat images from USGS, processed with respect to Landsat-5 (1988, 1995, 2000, 2005 and 2010), Landsat-8 (2017), identified change in land use, spatial temporal analysis of urban trends in terms of spread of built morphology, depletion of water bodies, reduction in vegetation and increase in temperature due to haphazard developments. Land surface temperature is the radioactive skin temperature of land surface. LST is determined by the land surface energy balance and varies rapidly because of the low thermal inertia of the land surface. It is essential to integrate the mitigation considerations for organized developments by deriving an effective spatial land use planning and related DCRs. The LANDSAT-4, 5, 8 TM data was processed with layer stacking and the LST and other related parameters like NDVI and Land Use-Land Cover (LULC) were retrieved in order to study the spatio-temporal UHI effect over Guntur city. For calculating the LST values, the DN values of the imageries were converted into the radiance values. On the basis of available Geo TIFF format data, and it had been directly converted it into radiance data using ArcGIS software. Through the landsat data input the Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), Normalized Difference water Index (NDWI) and Normalized Difference Built-up index (NDBI) have been analyzed. The paper reviews the factors contributing to UHI, and identified the maximum and minimum UHI intensified patches in Guntur city. Land surface temperature was computed using the Mono-window algorithm for the months of April, May 1991, 2001, 2011 and 2017. The range of minimum and maximum temperature showed an increase by time, thus indicating increased temperatures and an onset of urban heat island effect. Spatially, the mean LST changes over time were found to be directly related to change in the LULC and NDVI. It is essential and crucial to have city level planning consideration to reduce the impact of UHI to conserve the energy. The overlaying analysis, spatial temporal considerations and through regression analysis, the effective planning strategies have been identified to reduce the 7°C temperature. It is found that LST is inversely proportion to NDVI and NDWI. Subsequently the NDVI is directly proportion to NDWI, so it indicates that increase in vegetation cover increases the water conservation, so increase in vegetation decreases the UHI effect, so planning strategies related blue and green considerations and sustainable cum green development rules would reduce the heat island effect, in turn, it saves energy consumption in buildings.

Keywords: Landsat-5, Landsat-8, vegetation patches, built-up areas, water bodies, AGIS, linear programme and regression

Cite this Article

Srikonda Ramesh, Joseph Kumar P. Urban Planning Mitigation Trajectories for Urban Heat Island (UHI): Case Study of Guntur, Andhra Pradesh, India. Journal of Energy, Environment & Carbon Credits. 2018; 8(2): 12–29p.