Investigating local climate zones for outdoor thermal comfort assessment in an Indian city

Rajashree Kotharkar,Abhay Agrawal,Anurag Bagade

doi:10.5937/gp23-24251

Abstract

The rapid growth of development and urbanization in the Indian subcontinents has made the urban areas vulnerable to outdoor thermal discomfort (OTC) which is in turn affecting the quality of living in these areas. This study aims at evaluating spatiotemporal dynamics of outdoor thermal comfort in Nagpur city (India) during winter, summer and heat wave period using Local Climate Zone (LCZ) classification. It uses Thom's Discomfort Index (DI) and Relative Strain Index (RSI) to analyze outdoor thermal comfort. It also examines the significance of major LCZs in addressing thermal anomaly and OTC at different time periods using One-way ANOVA technique. It identifies critical LCZ having a maximum exposure of discomfort and concludes with the applicability of LCZ for addressing discomfort.

Highlights

Rapid development and urbanization have changed various physical factors such as built to open space ratio, use of impervious construction materials, affecting the microclimate in urban areas (Rose et al, 2011)
This study explores Local Climate Zone (LCZ), a proven classification system for understanding and evaluating the thermal environment of urban and rural studies, as a potential guideline for assessing outdoor thermal comfort in tropics
For LCZ 6B, greater vegetation cover and location at inner city regions contribute to the negative thermal anomaly and lower discomfort ranges for a major period of time

Summary

Introduction

Rapid development and urbanization have changed various physical factors such as built to open space ratio, use of impervious construction materials, affecting the microclimate in urban areas (Rose et al, 2011). Due to diverse landscape, socio-economic conditions and climate variations pose a difficulty in assessing thermal comfort for an entire city. Culminating outdoor comfort assessment research into a citywide planning proposal presents practical difficulties. Use of appropriate scale emerges as an important factor when existing studies demand comparative evaluation before transforming into policies or guidelines for city-level planning (Bajšanski et al 2015, Milošević et al 2017). As the scale gets bigger, it becomes difficult to gather and assess information on all the parameters affecting comfort. This leads to the need for standardization for outdoor thermal comfort studies (Johansson et al, 2014). Accounting climatic variables through a top to bottom approach at a national or regional level diminishes local mitigation opportunities

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