Numerical modelling for analysis of the effect of different urban green spaces on urban heat load patterns in the present and in the future

Tamás Gál,Sándor István Mahó,Nóra Skarbit,János Unger

doi:10.1016/j.compenvurbsys.2021.101600

Tamás Gál, Sándor István Mahó + Show 2 more

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https://doi.org/10.1016/j.compenvurbsys.2021.101600

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Journal: Urban Systems	Publication Date: Jan 25, 2021
Citations: 26	License type: cc-by

Affiliation: University of Szeged

Abstract

This paper focuses on urban green spaces in terms of climate and human thermal comfort containing their effect on heat load mitigation. It incorporates a modelling study in which the role of green spaces was investigated in terms of heat stress modification by applying MUKLIMO_3 model. During the experiment, the thermal effects of dense trees, scattered trees, grasslands and mixed green infrastructure has been investigated in the case of Szeged (Hungary) and assessed using different climate indices. The investigations encompassed 3 climatological time periods (1981–2010, 2021–2050 and 2071–2100) and two emission scenarios for future climate (RCP4.5 and RCP8.5). It was found that urban green spaces (e.g. parks) generally cool the environment, although, the cooling potential of the different green types differs. The highest reduction of heat load was found in the case of large urban parks comprising of dense trees near the downtown. The spatial extension of detected cooling was found small. However, it would increase during the future, especially in the case of grasslands. For urban planners, it is highly recommended to introduce new green sites within a city and to increase the spatial extension of the existing ones to mitigate and adapt to the impacts of climate change in the urban environment.

Highlights

Nowadays climatological research has become the focus of attention as recent and future climate change is a potential threat to our society, whose effects will be perceptible all over the globe, including cities (Stocker et al, 2013)
Urban climate research investigates different local climate modifications caused by built environments, in addition it attempts to provide reliable forecasts for future climatic trends at local scale
Climate change modelling is a complex process that uses general circulation models (GCMs) that can simulate a wide range of physical processes at a global scale (Bader et al, 2008)

Summary

Introduction

Nowadays climatological research has become the focus of attention as recent and future climate change is a potential threat to our society, whose effects will be perceptible all over the globe, including cities (Stocker et al, 2013). Urban climate research investigates different local climate modifications caused by built environments, in addition it attempts to provide reliable forecasts for future climatic trends at local scale. To represent local scale atmospheric phenomena, Regional Climate Models (RCM) are applied, which contain detailed physical processes determining the local climate. These models are commonly nested into GCMs as their output data serve as lateral boundary conditions for them (McGregor, 1997). The 5th Assessment Report of the IPCC contains four future emission scenarios called them as Representative Concentration Pathways (RCPs) that are distinguished by the enhanced radiative forcings resulting from different predicted rates of greenhouse gas emissions (Stocker et al, 2013). Each RCP sce nario can result different future climatic patterns

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