The Impact of Albedo Increase to Mitigate the Urban Heat Island in Terni (Italy) Using the WRF Model

Abstract

Abstract:The impacts of the urban heat island (UHI) phenomenon on energy consumption, air quality, and human health have been widely studied and described. Mitigation strategies have been developed to fight the UHI and its detrimental consequences. A potential countermeasure is the increase of urban albedo by using cool materials. Cool materials are highly reflective materials that can maintain lower surface temperatures and thus can present an effective solution to mitigate the UHI. Terni's proven record of high temperatures along with related environmental and comfort issues in its urban areas have reflected the local consequences of global warming. On the other hand, it promoted integrated actions by the government and research institutes to investigate solutions to mitigate the UHI effects. In this study, the main goal is to investigate the effectiveness of albedo increase as a strategy to tackle the UHI, by using the Weather Research and Forecasting (WRF) mesoscale model to simulate the urban climate of Terni (Italy). Three different scenarios through a summer heat wave in the summer of 2015 are analyzed. The Base Scenario, which simulates the actual conditions of the urban area, is the control case. In the Albedo Scenario (ALB Scenario), the albedo of the roof, walls and road of the whole urban area is increased. In the Albedo-Industrial Scenario (ALB-IND Scenario), the albedo of the roof, walls and road of the area occupied by the main industrial site of Terni, located in close proximity to the city center, is increased. The simulation results show that the UHI is decreased up to 2 • C both at daytime and at nighttime in the ALB and in ALB-IND Scenarios. Peak temperatures in the urban area can be decreased by 1 • C at daytime, and by about 2 • C at nighttime. Albedo increase in the area of interest might thus represent an opportunity to decrease the UHI effect and its consequences.

Mapping the Influence of Land Use/Land Cover Changes on the Urban Heat Island Effect—A Case Study of Changchun, China

“…Sustainability 2017, 9, 312 3 of 17 and there has been an obvious increasing trend in the mean air temperature. The highest monthly average temperature is 23.1 °C in July and the lowest is −15.6 °C in January.…”

“…Thus, it has become a major research focus in urban climatology and urban ecology since first reported in 1818 [16]. To have a better understanding of the UHI effects is very important for providing a scientific basis for future climate mitigation and urban planning [17,18].…”

A comparison between London and Baghdad surface urban heat islands and possible engineering mitigation solutions

“…Other techniques to study the UHI and simulate the urban climate are present in the literature such as Research and Forecasting (WRF) and ENVI-met. Morini, Touchaei, Castellani, Rossi, and Cotana (2016) employed the WRF coupled to multi-layer urban canopy model (UCM) and building energy model (BEM) to study the impact of albedo increase to mitigate the UHI. Shen, Chow, and Darkwa (2013) used the ENVI-met to simulate urban climate parameters to evaluate the influence of microclimatic design on mitigating the UHI effects.…”

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“…• significant economic benefits for the private side and energy/environmental benefits for the collective side; • better local quality of cities and more livable outdoor and indoor conditions; and • opportunities to address the impacts and challenges of urban heat islands [17], as well as to achieve the targets of sustainability promoted by the countries at international levels.…”