Analyzing the impact of changing landscape pattern and dynamics on land surface temperature in Lucknow city, India

Abstract

The increasing urbanization has hampered the overall livelihood of urban dwellers. Urban heat island (UHI) is a significant consequence of urbanization on the earth's environment. Its geographical pattern, impact, and mitigation strategies remain poorly understood over large areas. The study aims at determining and analyzing how changing landscape patterns (at macro-level) and dynamics (at micro-level) affect the land surface temperature (LST). The macro pattern analysis is performed by examining the spatial variation of LST with the distribution of green space (GS) and impervious surface (IS). Whereas, micro dynamics analysis is carried out by critical examination of the city's environmental health condition. To this end, an environmental health index (EHI) is derived based on the relation of land surface temperature variation index (LSTVI) with (i) UHI intensity, (ii) green space density (GSD), and (iii) impervious surface density (ISD). Moreover, we determined the impact of various types of sprawl expansion and drivers in developing UHI phenomenon in Lucknow city, India, from 2005–2016. The results show an increased impervious density and decreased greenness density over the study years. The mean LST of IS is found to be 4 °C higher than that of GS in 2005, which further increased to 6 °C in the year 2016. The results from macro pattern analysis depict a significantly strong correlation between mean LST, ISD (positive) and GSD (negative) along the rural-urban gradients. The results from the micro dynamics analysis are interpreted as an EHI rating for specific zones going through the UHI phenomenon. Overall the study reveals an adverse effect of decreasing greenness density and advocates the vital role of GS in mitigating UHI effects. Our study also highlights UHI spatial pattern and its driving factors, suggesting various effective mitigation strategies for suppressing the UHI effect and providing a scientific basis for sustainable development.