scholarly journals Accelerating Urban Heating Under Land-Cover and Climate Change Scenarios in Indonesia: Application of the Universal Thermal Climate Index

2021 ◽  
Vol 7 ◽  
Author(s):  
Martiwi Diah Setiawati ◽  
Marcin Pawel Jarzebski ◽  
Martin Gomez-Garcia ◽  
Kensuke Fukushi

Climate change causing an increase of frequency and magnitude of heat waves has a huge impact on the urban population worldwide. In Indonesia, the Southeast Asian country in the tropical climate zone, the increasing heat wave duration due to climate change will be also magnified by projected rapid urbanization. Therefore, not only climate change mitigation measures but also adaptation solutions to more frequent extreme weather events are necessary. Adaptation is essential at local levels. The projected increase of the heat wave duration will trigger greater health-related risks. It will also drive higher energy demands, particularly in urban areas, for cooling. New smart solutions for growing urbanization for reducing urban heat island phenomenon are critical, but in order to identify them, analyzing the changing magnitude and spatial distribution of urban heat is essential. We projected the current and future spatial variability of heat stress index in three cities in Indonesia, namely, Medan, Surabaya, and Denpasar, under climate change and land-cover change scenarios, and quantified it with the Universal Thermal Climate Index (UTCI) for two periods, baseline (1981–2005) and future (2018–2042). Our results demonstrated that currently the higher level of the UTCI was identified in the urban centers of all three cities, indicating the contribution of urban heat island phenomenon to the higher UTCI. Under climate change scenarios, all three cities will experience increase of the heat, whereas applying the land-cover scenario demonstrated that in only Medan and Denpasar, the UTCI is likely to experience a higher increase by 3.1°C; however, in Surabaya, the UTCI will experience 0.84°C decrease in the period 2018–2042 due to urban greening. This study advanced the UTCI methodology by demonstrating its applicability for urban heat warning systems and for monitoring of the urban green cooling effect, as well as it provides a base for adaptation measures’ planning.

Author(s):  
Sushobhan Sen ◽  
Juan Pablo Ricardo Mendèz-Ruiz Fernandèz ◽  
Jeffery Roesler

Paved surfaces, especially parking lots, occupy a significant proportion of the horizontal surface area in cities. The low albedo of many of these parking lots contribute to the urban heat island (UHI) and affect the local microclimate around them. The albedo of six parking lots in Champaign-Urbana, U.S., was measured using a ground-based albedometer and was found to vary between 0.18 and 0.28, with a statistically significant variation in albedo at different points within each parking lot. The numerical model ENVI-met was then employed to model the microclimate around one of these lots to examine the potential of increasing its albedo to mitigate UHI. The higher albedo decreased the air temperature over the parking lot by about 1°C. Furthermore, the Universal Thermal Climate Index (UTCI), which combines the effects of air temperature, reflected radiation, wind speed, clothing, metabolism, and humidity, demonstrated that increasing the albedo of the parking lot could improve overall pedestrian thermal comfort and even eliminate it during several hours of the day, and thus mitigate the UHI effect.


2021 ◽  
Author(s):  
Tim van der Schriek ◽  
Konstantinos V. Varotsos ◽  
Dimitra Founda ◽  
Christos Giannakopoulos

<p>Historical changes, spanning 1971–2016, in the Athens Urban Heat Island (UHI) over summer were assessed by contrasting two air temperature records from established meteorological stations in urban and rural settings. When contrasting two 20-year historical periods (1976–1995 and 1996–2015), there is a significant difference in summer UHI regimes. The stronger UHI-intensity of the second period (1996–2015) is likely linked to increased pollution and heat input. Observations suggest that the Athens summer UHI characteristics even fluctuate on multi-annual basis. Specifically, the reduction in air pollution during the Greek Economic Recession (2008-2016) probable subtly changed the UHI regime, through lowering the frequencies of extremely hot days (T<sub>max</sub> > 37 °C) and nights (T<sub>min</sub> > 26 °C).</p><p>Subsequently, we examined the future temporal trends of two different UHIs in Athens (Greece) under three climate change scenarios. A five-member regional climate model (RCM) sub-ensemble from EURO-CORDEX with a horizontal resolution of 0.11° (~12 × 12 km) simulated air temperature data, spanning the period 1976–2100, for the two station sites. Three future emissions scenarios (RCP2.6, RCP4.5 and RCP8.5) were implanted in the simulations after 2005. The observed daily maximum and minimum air temperature data (T<sub>max</sub> and T<sub>min</sub>) from two historical UHI regimes (1976–1995 and 1996–2015, respectively) were used, separately, to bias-adjust the model simulations thus creating two sets of results.</p><p>This novel approach allowed us to assess future temperature developments in Athens under two different UHI intensity regimes. We found that the future frequency of days with T<sub>max</sub> > 37 °C in Athens was only different from rural background values under the intense UHI regime. There is a large increase in the future frequency of nights with T<sub>min</sub> > 26 °C in Athens under all UHI regimes and climate scenarios; these events remain comparatively rare at the rural site.</p><p>This study shows a large urban amplification of the frequency of extremely hot days and nights which is likely forced by increasing air pollution and heat input. Consequently, local mitigation policies aimed at decreasing urban atmospheric pollution are expected to be also effective in reducing urban temperatures during extreme heat events in Athens under all future climate change scenarios. Such policies therefore have multiple benefits, including: reducing electricity (energy) needs, improving living quality and decreasing heat- and pollution related illnesses/deaths.</p><p> </p>


Proceedings ◽  
2017 ◽  
Vol 1 (5) ◽  
pp. 106 ◽  
Author(s):  
Marcos Vinicius Bueno de Morais ◽  
Viviana Vanesa Urbina Guerrero ◽  
Leila Droprinchinski Martins ◽  
Jorge Alberto Martins

2020 ◽  
Author(s):  
Alrun Jasper-Tönnies ◽  
Yannick Back ◽  
Peter Bach ◽  
Wolfgang Rauch ◽  
Thomas Einfalt ◽  
...  

<p>Unsere Städte sind kontinuierlichen Veränderungen unterworfen. Das Bevölkerungswachstum führt zu einem steigenden Bedarf an Wohn-, Gewerbe- und Verkehrsflächen und damit zu voranschreitender Versiegelung von natürlichen Flächen. Durch den Klimawandel sind unter anderem vermehrt auftretende Starkniederschläge, aber auch längere Trockenperioden und Hitzewellen zu erwarten (z.B. IPCC, 2014). Somit sehen sich Städte in naher Zukunft großen Herausforderungen ausgesetzt. Gleichzeitig sind Ressourcen für Anpassungsmaßnahmen begrenzt, und Flächen, die für Anpassungsmaßnahmen benötigt würden, stehen unter hoher Nutzungskonkurrenz. Vor diesem Hintergrund rücken Anpassungsmaßnahmen in den Vordergrund, die einen mehrfachen Nutzen aufweisen, wie dezentrale Entwässerungsmaßnahmen. Durch die Behandlung von Niederschlagswasser direkt vor Ort können gleichzeitig Grünflächen und Schattenplätze geschaffen, sowie Infiltration, Evapotranspiration und die Speicherung von Wasser gesteigert werden. Neben einer Entlastung des städtischen Abwassersystems kommt es damit auch zu einer Verbesserung des urbanen Mikroklimas und zu einer Minderung von Hitzeinseln. Die Auswirkung dezentraler Entwässerungssysteme auf das urbane Mikroklima wurde hier am Beispiel der Stadt Innsbruck näher untersucht. Zukünftige Klimaänderungen wurden anhand von Beobachtungsdaten und regionalen Klimaprojektionen aus EURO-CORDEX/ReKliEs unter Berücksichtigung verschiedener RCP-Szenarien (Abb. 1, 2) abgeschätzt. Indikatoren wie der Universal Thermal Climate Index wurden mittels eines vereinfachten Ansatzes in Abhängigkeit von lokalen Standorteigenschaften in einem GIS (Geoinformationssystem) simuliert (Back et al., 2020). Dieser Ansatz dient der Analyse urbaner Hitze auf mehreren Maßstabsebenen und kann unter Berücksichtigung verschiedener RCP-Szenarien durchgeführt werden (Abb. 3). Eine Koppelung dieses Ansatzes mit einem Ansatz nach Simperler et al. (2018), zur Differenzierung städtischer Strukturtypen und ihrer Potenziale und Einschränkungen für die dezentrale Niederschlagswasserbehandlung, soll prioritäre Gebiete zur Einbettung optimierter Anpassungsmaßnahmen lokalisieren und dadurch Synergieeffekte fördern. Diese Arbeit ist Teil der Projekte CONQUAD (Projekt Nr. KR16AC0K13143) und cool-INN (Projekt Nr. KR19SC0F14953), welche vom Österreichischen Klima- und Energiefonds gefördert werden.</p><p><strong>Literatur</strong></p><p>Back, Y., Bach, P.M., Jasper-Tönnies, A., Rauch, W. und Kleidorfer, M. (2020). A rapid fine-scale approach to modelling urban bioclimatic conditions. Science of the Total Environment. Revision Process.</p><p>Intergovernmental Panel on Climate Change (IPCC). (2014). Summary for policymakers. IN: Climate Change 2014: Impacts, Adaptation and Vulnerability. Part A: Global and sectoral Aspects. Contribution of Working Group II of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 1-32.</p><p>Simperler, L., Himmelbauer, P., Stöglehner, G. und Ertl, T. (2018). Siedlungswasserwirtschaftliche Strukturtypen und ihre Potenziale für die dezentrale Bewirtschaftung von Niederschlagswasser. Österreichische Wasser- und Abfallwirtschaft, Wien.</p><p><img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gnp.8dc32f38488f51196672061/sdaolpUECMynit/21-TKD&app=m&a=0&c=b90baff20f885e52746c33cca59e5d0c&ct=x&pn=gnp.elif" alt="" width="525" height="378"></p><p><img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gnp.9cad14f6488f50856672061/sdaolpUECMynit/21-TKD&app=m&a=0&c=381acd600b8ccddf546902279086aa4b&ct=x&pn=gnp.elif" alt="" width="433" height="291"></p><p><img src="https://contentmanager.copernicus.org/fileStorageProxy.php?f=gnp.3eefdc36488f56936672061/sdaolpUECMynit/21-TKD&app=m&a=0&c=ee59c3cd5d6e5663a3d4c996da0683b7&ct=x&pn=gnp.elif" alt=""></p>


Author(s):  
Marcos Vinicius Bueno de Morais ◽  
Viviana Vanesa Urbina Guerrero ◽  
Anderson Paulo Rudke ◽  
Thais Fujita ◽  
Leila Droprinchinski Martins ◽  
...  

According to IPCC reports, global climate change is likely to be accompanied by a greater frequency, intensity, and duration of heat waves in urban areas. This is related to predicted and ongoing variation of atmospheric temperature and its association with the dynamical evolution of cities. Changes in the roughness pattern of the surface, wind intensity, soil available humidity and radiative properties compared to the natural surfaces characterize the formation of the Urban Heat Island (UHI). A dynamical downscaling of A2 and B1 SRES’s future scenarios from Intergovernmental Panel on Climate Change were performed for Londrina, a medium-size city of Southern Brazil, using the Weather Research and Forecasting model. The main objective of this study is to investigate the impact of these scenarios on the UHI formation and intensity based on different input data, and its role and influence in the rural area. For this, an evaluation of the model and a comparison with the scenarios were done to mitigate the current trends. The results show a tendency in the current situation in following the pessimistic A2 scenario. Also, a drier rural area for the sustainable projection (B1) is found which implicates in a higher temperature and wind patterns modification for both sites, urban and rural region. Both future projections have a direct influence on the UHI intensity and formation, yielding effects in the agriculture and affecting conditions on human comfort over the region.


Atmosphere ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1159
Author(s):  
Igor Žiberna ◽  
Nataša Pipenbaher ◽  
Daša Donša ◽  
Sonja Škornik ◽  
Mitja Kaligarič ◽  
...  

The human population is increasing. The ongoing urbanization process, in conjunction with climate change, is causing larger environmental footprints. Consequently, quality of life in urban systems worldwide is under immense pressure. Here, the seasonal characteristics of Maribor’s urban thermal environment were studied from the perspectives of surface urban heat island (SUHI) and urban heat island (UHI) A remote sensing thermal imagery time series and in-situ measurements (stationary and mobile) were combined with select geospatial predictor variables to model this atmospheric phenomenon in its most intensive season (summer). Finally, CMIP6 climate change scenarios and models were considered, to predict future UHI intensity. Results indicate that Maribor’s UHI intensity maximum shifted from winter to spring and summer. The implemented generalized additive model (GAM) underestimates UHI intensity in some built-up parts of the study area and overestimates UHI intensity in green vegetated areas. However, by the end of the century, UHI magnitude could increase by more than 60% in the southern industrial part of the city. Such studies are of particular concern, in regards to the increasing frequency of heat waves due to climate change, which further increases the (already present) heat stress in cities across the globe.


Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 546
Author(s):  
Andreas Matzarakis

In the era of climate change, before developing and establishing mitigation and adaptation measures that counteract urban heat island (UHI) effects [...]


2021 ◽  
Vol 13 (3) ◽  
pp. 1099
Author(s):  
Yuhe Ma ◽  
Mudan Zhao ◽  
Jianbo Li ◽  
Jian Wang ◽  
Lifa Hu

One of the climate problems caused by rapid urbanization is the urban heat island effect, which directly threatens the human survival environment. In general, some land cover types, such as vegetation and water, are generally considered to alleviate the urban heat island effect, because these landscapes can significantly reduce the temperature of the surrounding environment, known as the cold island effect. However, this phenomenon varies over different geographical locations, climates, and other environmental factors. Therefore, how to reasonably configure these land cover types with the cooling effect from the perspective of urban planning is a great challenge, and it is necessary to find the regularity of this effect by designing experiments in more cities. In this study, land cover (LC) classification and land surface temperature (LST) of Xi’an, Xianyang and its surrounding areas were obtained by Landsat-8 images. The land types with cooling effect were identified and their ideal configuration was discussed through grid analysis, distance analysis, landscape index analysis and correlation analysis. The results showed that an obvious cooling effect occurred in both woodland and water at different spatial scales. The cooling distance of woodland is 330 m, much more than that of water (180 m), but the land surface temperature around water decreased more than that around the woodland within the cooling distance. In the specific urban planning cases, woodland can be designed with a complex shape, high tree planting density and large planting areas while water bodies with large patch areas to cool the densely built-up areas. The results of this study have utility for researchers, urban planners and urban designers seeking how to efficiently and reasonably rearrange landscapes with cooling effect and in urban land design, which is of great significance to improve urban heat island problem.


Urban Science ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 19
Author(s):  
Robert Dare

This article presents a customized system dynamics model to facilitate the informed development of policy for urban heat island mitigation within the context of future climate change, and with special emphasis on the reduction of heat-related mortality. The model incorporates a variety of components (incl.: the urban heat island effect; population dynamics; climate change impacts on temperature; and heat-related mortality) and is intended to provide urban planning and related professionals with: a facilitated means of understanding the risk of heat-related mortality within the urban heat island; and location-specific information to support the development of reasoned and targeted urban heat island mitigation policy.


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