scholarly journals Projection of present and future daily and evening urban heat load patterns

2020 ◽  
Vol 54 (2) ◽  
pp. 19-27 ◽  
Author(s):  
János Unger ◽  
Nóra Skarbit ◽  
Tamás Gál
Keyword(s):  
Heat Load ◽  
Temporal Change ◽  
Urban Climate ◽  
Regional Scale ◽  
Thermal Conditions ◽  
Urban Environments ◽  
City Centre ◽  
Climate Indices ◽  
Local Climate ◽  
Thermal Climate

In this modeling study the recent and future daily and evening thermal climate of a Central-European city (Szeged, Hungary) was investigated in terms of heat load modification by applying MUKLIMO_3 model to project daily and evening climate indices. For surface parameterization the Local Climate Zone (LCZ) scheme was used. The investigation encompassed three climatological time periods (1981–2010, 2021–2050 and 2071–2100) and two emission scenarios for future climate (RCP4.5 and RCP8.5). Our results show that highest index values appear in the city centre and stretch to the NW direction (LCZs 2, 3 and 8) and they decrease towards to the vegetated rural surfaces (mainly LCZ D). That is, the values depend on the zone types and there are more days towards to the densely built-up LCZs. Also, a general temporal change can be detected as the index patterns show the substantial increasing tendency for both indices towards the end of this century. This temporal change suggests a two-way conclusion: first, the increasing number of hot days means a strongly deteriorating change of unfavourable thermal conditions, and second, the change in the number of the evening index provides more opportunities for regeneration and leisure-time activities outdoors in the already thermally less stressful evening hours for the urban inhabitants. This study gives very illustrative examples on the expected climate changes during this century and these examples show that there are several sides to these changes in urban environments. Furthermore, they clearly prove that global or regional scale climate predictions without urban climate interactions do not have enough detailed information.

scholarly journals Investigating the effect of land-use change on the heat load within two Austrian cities

2021 ◽  
Author(s):  
Robert Goler ◽  
Maja Žuvela-Aloise ◽  
Sandro Oswald ◽  
Brigitta Holllósi ◽  
Claudia Hahn ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Heat Load ◽  
Climate Model ◽  
Land Use Changes ◽  
Urban Climate ◽  
Climate Indices ◽  
Local Climate ◽  
Use Categories

<p>As the majority of the population live in cities, it is important to understand the urban climate and how it can change in the future. Accordingly, the ACRP-funded project LUCRETIA investigates how land use and land cover determine local climate characteristics within cities in Austria. </p><p>Historical land use data has been obtained for Graz and Vienna for a number of years and used as input into the microscale urban climate model MUKLIMO_3 to simulate both cities in conditions representing a typical summer day. In conjunction with the cuboid method, climate indices such as the average number of summer and hot days per year have been calculated to establish how the heat load changes from one year to another. Differences in the heat load have been related to changes in the land use focusing on (i) the change that occurs in situ and (ii) the change that occurs in the neighbourhood. <br> <br>It is shown that land use categories can be ordered according to their heat load, with categories containing larger amounts of greenery generally having lower heat loads. With the land use categories sorted in such a way, it enables a relatively quick assessment to be made of the effect of replacing one land use category with another, without having to employ expensive modelling tools. Furthermore, it is shown that land-use changes not only affect the heat load of the changed area in situ, but also the neighbourhood around where the change was made. This demonstrates that land-use changes may have a broader spatial impact than initially anticipated. The results from this study can serve as guidance for city planners regarding future land use and land cover changes.</p>

Urban climate zone classification using convolutional neural network and ground-level images

2019 ◽  
Vol 43 (3) ◽  
pp. 410-424 ◽  
Author(s):  
Guang Xu ◽  
Xuan Zhu ◽  
Nigel Tapper ◽  
Benjamin Bechtel
Keyword(s):  
Urban Climate ◽  
Three Dimensional ◽  
Ground Level ◽  
Critical Issue ◽  
Urban Environments ◽  
Bare Rock ◽  
Climate Zone ◽  
Local Climate ◽  
Climate Risks ◽  
Wide Range

Urban climate risks have a wide range of impacts on the health of more than 50% of the world’s population, which is a critical issue relating to climate change. To support urban climate study and categorise different urban environments and their atmospheric impacts in a consistent way, the Local Climate Zone (LCZ) classification scheme has been developed. The World Urban Database and Access Portal Tools project aims to map the LCZ of cities across the globe. However, previous classification approaches based on satellite images have limitations regarding the characterisation of three-dimensional features such as building heights. This study aims to apply convolutional neural networks to classify LCZ types based on ground-level images, which can provide more detail of the urban environments. Validation results have shown an overall accuracy of 69.6%. The new method outperformed previous satellite-based studies for classifying the LCZ types Compact Mid-rise, Sparsely Built, Heavy Industry, and Bare Rock or Paved.

scholarly journals Mapping Local Climate Zones and Their Applications in European Urban Environments: A Systematic Literature Review and Future Development Trends

2021 ◽  
Vol 10 (4) ◽  
pp. 260
Author(s):  
Michal Lehnert ◽  
Stevan Savić ◽  
Dragan Milošević ◽  
Jelena Dunjić ◽  
Jan Geletič
Keyword(s):  
Urban Areas ◽  
Urban Climate ◽  
Well Being ◽  
Climatic Conditions ◽  
Urban Environments ◽  
Outdoor Thermal Comfort ◽  
Climate Zones ◽  
Local Climate ◽  
Local Climate Zones ◽  
Scale Modelling

In the light of climate change and burgeoning urbanization, heat loads in urban areas have emerged as serious issues, affecting the well-being of the population and the environment. In response to a pressing need for more standardised and communicable research into urban climate, the concept of local climate zones (LCZs) has been created. This concept aims to define the morphological types of (urban) surface with respect to the formation of local climatic conditions, largely thermal. This systematic review paper analyses studies that have applied the concept of LCZs to European urban areas. The methodology utilized pre-determined keywords and five steps of literature selection. A total of 91 studies were found eligible for analysis. The results show that the concept of LCZs has been increasingly employed and become well established in European urban climate research. Dozens of measurements, satellite observations, and modelling outcomes have demonstrated the characteristic thermal responses of LCZs in European cities. However, a substantial number of the studies have concentrated on the methodological development of the classification process, generating a degree of inconsistency in the delineation of LCZs. Recent trends indicate an increasing prevalence of the accessible remote-sensing based approach over accurate GIS-based methods in the delineation of LCZs. In this context, applications of the concept in fine-scale modelling appear limited. Nevertheless, the concept of the LCZ has proven appropriate and valuable to the provision of metadata for urban stations, (surface) urban heat island analysis, and the assessment of outdoor thermal comfort and heat risk. Any further development of LCZ mapping appears to require a standardised objective approach that may be globally applicable.

scholarly journals Data for the geoecology of solution karst dolines, with particular attention to climatic, soil and biogenic environment

2021 ◽  
Vol 55 (4) ◽  
pp. 27-71
Author(s):  
Ilona Bárány Kevei ◽  
Zoltán Zboray ◽  
Márton Kiss
Keyword(s):  
21St Century ◽  
Heat Load ◽  
Climate Model ◽  
Model Simulation ◽  
Urban Climate ◽  
Climate Index ◽  
Local Climate ◽  
Tropical Night ◽  
Mitigation And Adaptation ◽  
Local Climate Zones

In this study the changes in the nighttime heat load in Carpathian Basin cities during the 21st century were examined. To quantify the heat load, the tropical night climate index was used. The MUKLIMO_3 local scale climate model was used to describe the urban processes and the land use classes were defined by the local climate zones. The expected change was examined over three periods: the 1981–2010 was taken as reference period using the Carpatclim database and the 2021–2050 and 2071–2100 future periods using EURO-CORDEX regional model simulation data for two scenarios (RCP4.5 and RCP8.5). To combine the detailed spatial resolution and the long time series, a downscaling method was applied. Our results show that spectacular changes could be in the number of tropical nights during the 21st century and the increasing effect of the urban landform is obvious. In the near future, a slight increase can be expected in the number of tropical nights, which magnitude varies from city to city and there is no major difference between the scenarios. However, at the end of the century the results of the two scenarios differ: the values can be 15-25 nights in case of RCP4.5 and 30-50 nights in case of RCP8.5. The results show that dwellers could be exposed to high heat load in the future, as the combined effect of climate change and urban climate, thus developing various mitigation and adaptation strategies is crucial.

scholarly journals Anthropogenic and natural drivers of a strong winter urban heat island in a typical Arctic city

2018 ◽  
Author(s):  
Mikhail Varentsov ◽  
Pavel Konstantinov ◽  
Alexander Baklanov ◽  
Igor Esau ◽  
Victoria Miles ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Temperature Anomaly ◽  
Urban Climate ◽  
Thermal Conditions ◽  
Cold Climate ◽  
The Arctic ◽  
City Centre ◽  
Heat Island ◽  
Strong Argument ◽  
Urban Heat

Abstract. The Arctic has rapidly urbanized in recent decades with two million people currently living in more than a hundred cities north of 65° N. These cities have a harsh but sensitive climate and warming here is the principle driver of destructive thawing, water leakages, air pollution, and other detrimental environmental impacts. This study reports on the urban temperature anomaly in a typical Arctic city. This persistent warm anomaly reaches up to 11  K in winter with the wintertime mean urban temperature being on average 1.9 K higher in the city centre than in the surrounding natural landscape. An urban temperature anomaly, also known as an urban heat island (UHI), was found in remote sensing and in situ temperature data. High-resolution (1 km) model experiments run with and without an urban surface parametrization helped to identify the leading physical and geographical factors supporting a strong temperature anomaly in a cold climate. The statistical analysis and modelling suggest that direct anthropogenic heating contributes at least 50 % to the observed UHI intensity, and the rest is created by natural microclimatic variability over the undulating relief of the area. The current UHI effect can be as large as the projected, and already amplified, warming for the region in the 21st century. In contrast to earlier reports, this study found that the wintertime UHI in the Arctic should be largely attributed to direct anthropogenic heating. This is a strong argument in support of energy efficiency measures, urban climate change mitigation policy, and against high-density urban development in polar settlements. The complex pattern of thermal conditions, as revealed in this study, challenges urban planners to account for the observed micro-climatic diversity in perspective sustainable development solutions.

The physical environment

2018 ◽  
Author(s):  
Philip James
Keyword(s):  
Physical Environment ◽  
Urban Climate ◽  
Urban Environments ◽  
Artificial Light ◽  
Noise Levels ◽  
Light At Night ◽  
High Noise ◽  
P Elements ◽  
Micro Organisms ◽  
Diversity Of Life

Elements of the physical aspects of urban environments determine which micro-organisms, plants, and animals live in urban environments. In this chapter, climate, air, water, soil, noise, and light are discussed. Urban environments are affected by the climate of the region in which they are located, and in turn and create their own, distinctive urban climate. Air, water, and soil are all affected by urbanization. Pollution of these elements is common. High noise levels and artificial light at night (ALAN—a new phenomenon) are both strongly associated with urban environments. Details of both are discussed. The discussion in this chapter provides a foundation for further exploration of the diversity of life in urban environments and for later exploration of how organisms adapt to urban living, which will be discussed in Parts II and III.

scholarly journals Urban Climates and Climate Change

2020 ◽  
Vol 45 (1) ◽  
pp. 411-444 ◽  
Author(s):  
Valéry Masson ◽  
Aude Lemonsu ◽  
Julia Hidalgo ◽  
James Voogt
Keyword(s):  
Climate Change ◽  
Climate Modeling ◽  
Regional Climate ◽  
Urban Climate ◽  
Regional Climate Modeling ◽  
Climate Impact ◽  
Local Climate ◽  
Urban Climatology ◽  
Recent Developments ◽  
Global Agenda

Cities are particularly vulnerable to extreme weather episodes, which are expected to increase with climate change. Cities also influence their own local climate, for example, through the relative warming known as the urban heat island (UHI) effect. This review discusses urban climate features (even in complex terrain) and processes. We then present state-of-the-art methodologies on the generalization of a common urban neighborhood classification for UHI studies, as well as recent developments in observation systems and crowdsourcing approaches. We discuss new modeling paradigms pertinent to climate impact studies, with a focus on building energetics and urban vegetation. In combination with regional climate modeling, new methods benefit the variety of climate scenarios and models to provide pertinent information at urban scale. Finally, this article presents how recent research in urban climatology contributes to the global agenda on cities and climate change.

scholarly journals Quantification of an atmospheric nucleation and growth process as a single source of aerosol particles in a city

2017 ◽  
Vol 17 (24) ◽  
pp. 15007-15017 ◽  
Author(s):  
Imre Salma ◽  
Veronika Varga ◽  
Zoltán Németh
Keyword(s):  
Growth Process ◽  
Particle Number ◽  
Urban Climate ◽  
Particle Diameter ◽  
City Centre ◽  
Time Interval ◽  
Single Source ◽  
Mean Values ◽  
Early Afternoon ◽  
The City

Abstract. Effects of a new aerosol particle formation (NPF) and particle diameter growth process as a single source of atmospheric particle number concentrations were evaluated and quantified on the basis of experimental data sets obtained from particle number size distribution measurements in the city centre and near-city background of Budapest for 5 years. Nucleation strength factors for a nucleation day (NSFNUC) and for a general day (NSFGEN) were derived separately for seasons and full years. The former characteristic represents the concentration increment of ultrafine (UF) particles specifically on nucleation days with respect to accumulation-mode (regional background) concentrations (particles with equivalent diameters of 100–1000 nm; N100−1000) due solely to the nucleation process. The latter factor expresses the contribution of nucleation to particle numbers on general days; thus, it represents a longer time interval such as season or year. The nucleation source had the largest effect on the concentrations around noon and early afternoon, as expected. During this time interval, it became the major source of particles in the near-city background. Nucleation increased the daily mean concentrations on nucleation days by mean factors of 2.3 and 1.58 in the near-city background and city centre, respectively. Its effect was largest in winter, which was explained by the substantially lower N100−1000 levels on nucleation days than those on non-nucleation days. On an annual timescale, 37 % of the UF particles were generated by nucleation in the near-city background, while NPF produced 13 % of UF particles in the city centre. The differences among the annual mean values, and among the corresponding seasonal mean values, were likely caused by the variability in controlling factors from year to year. The values obtained represent the lower limits of the contributions. The shares determined imply that NPF is a non-negligible or substantial source of particles in near-city background environments and even in city centres, where the vehicular road emissions usually prevail. Atmospheric residence time of nucleation-mode particles was assessed by a decay curve analysis, and a mean of 02:30 was obtained. The present study suggests that the health-related consequences of the atmospheric NPF and growth process in cities should also be considered in addition to its urban climate implications.

scholarly journals Universal thermal climate index in Russia

2019 ◽  
pp. 3-19 ◽  
Author(s):  
V. V. Vinogradova
Keyword(s):  
Cold Stress ◽  
Thermal Conditions ◽  
The Arctic ◽  
Climate Index ◽  
Universal Thermal Climate Index ◽  
Environment Temperature ◽  
European Part Of Russia ◽  
Thermal Climate ◽  
Actual Environment ◽  
Almost All

The paper uses the universal thermal climate index (UTCI) to estimate the bioclimate in Russia, initiated by the Commission of the International society of Biometeorology. The UTCI index can be described as equivalent environment temperature (°C), which provides the same physiological impact on humans as the actual environment. Assessment of bioclimatic conditions is shown for the territory of Russia in the period of modern climate change (2001–2015). Cold stress conditions (from low to extreme) were observed in the almost all territory of Russia for about 8–11 months a year. During the rest of the year, the conditions are neutral or comfortable. The period of extreme and very high cold stress is reduced during the modern climate warming (compared to the period 1961–1990), especially in the Arctic, in the European part of Russia, in Western and Eastern Siberia. At the same time, the period with neutral and comfortable thermal conditions increases.

Sign in / Sign up

Export Citation Format

Share Document