scholarly journals Sensitivity analysis of the PALM model system 6.0 in the urban environment

2020 ◽  
Author(s):  
Michal Belda ◽  
Jaroslav Resler ◽  
Jan Geletič ◽  
Pavel Krč ◽  
Björn Maronga ◽  
...  
Keyword(s):  
Urban Environment ◽  
Real Life ◽  
Mitigation Measures ◽  
Radiation Balance ◽  
Volumetric Heat Capacity ◽  
Effective Measure ◽  
Wall Conductivity ◽  
Urban Heat ◽  
Thermal Indicators ◽  
Life Type

Abstract. Sensitivity of the PALM model 6.0 is tested in a real urban environment in the vicinity of a typical crossroad in a densely built-up residential area in Prague, Czech Republic. Two types of scenarios are employed. First are the synthetic scenarios altering mainly surface and material parameters such as albedo, emissivity or wall conductivity, testing sensitivity of the model simulations to potentially erroneous setting of model inputs. Second, real-life type scenarios are analyzed, in which commonly considered urban heat island mitigation measures are applied, such as greening of the streets or changing surface materials. For the first-type scenarios, surface parameters used in radiation balance equations are found to be the most sensitive overall followed by volumetric heat capacity and thermal conductivity of walls. Other parameters show limited average effect, however, some can still be significant in some parts of the day, such as surface roughness in the morning hours. Second type, the mitigation scenarios, show urban vegetation to be the most effective measure, especially when considering both physical and biophysical temperature indicators. Influence of both type scenarios was also tested for air quality, specifically PM10 dispersion which generally shows behaviour opposite to thermal indicators, ie., improved thermal comfort brings deterioration of PM10 concentrations.

scholarly journals Sensitivity analysis of the PALM model system 6.0 in the urban environment

2021 ◽  
Vol 14 (7) ◽  
pp. 4443-4464
Author(s):  
Michal Belda ◽  
Jaroslav Resler ◽  
Jan Geletič ◽  
Pavel Krč ◽  
Björn Maronga ◽  
...  
Keyword(s):  
Urban Environment ◽  
Land Surface ◽  
Input Data ◽  
Model Performance ◽  
Mitigation Measures ◽  
Radiation Balance ◽  
Effective Measure ◽  
Wall Conductivity ◽  
Layer Flow ◽  
Thermal Indicators

Abstract. Sensitivity of the PALM model 6.0 with respect to land-surface and building properties is tested in a real urban environment in the vicinity of a typical crossroads in a densely built-up residential area in Prague, Czech Republic. The turbulence-resolving PALM is able to simulate the urban boundary layer flow for realistic setups. Besides an accurate representation of the relevant physical processes, the model performance also depends on the input data describing the urban setup, namely the building and land-surface properties. Two types of scenario are employed. The first one is the synthetic scenarios altering mainly surface and material parameters such as albedo, emissivity or wall conductivity, testing sensitivity of the model simulations to potentially erroneous input data. Second, urbanistic-type scenarios are analysed, in which commonly considered urban heat island mitigation measures such as greening of the streets or changing surface materials are applied in order to assess the limits of the effects of a particular type of scenario. For the synthetic scenarios, surface parameters used in radiation balance equations are found to be the most sensitive overall followed by the volumetric heat capacity and thermal conductivity of walls. Other parameters show a limited average effect; however, some can still be significant during some parts of the day, such as surface roughness in the morning hours. The second type, the urbanistic scenarios, shows urban vegetation to be the most effective measure, especially when considering both physical and biophysical temperature indicators. The influence of both types of scenario was also tested for air quality, specifically PM2.5 dispersion, which generally shows opposite behaviour to that of thermal indicators; i.e. improved thermal comfort brings deterioration of PM2.5 concentrations.

scholarly journals Combating Urban Heat Island Effect—A Review of Reflective Pavements and Tree Shading Strategies

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 93
Author(s):  
V. R. Sankar Cheela ◽  
Michele John ◽  
Wahidul Biswas ◽  
Prabir Sarker
Keyword(s):  
Urban Heat Island ◽  
Urban Forest ◽  
Critical Role ◽  
Tree Canopy ◽  
Mitigation Measures ◽  
Heat Island ◽  
Human Thermal Comfort ◽  
Urban Heat ◽  
Pavement Temperature ◽  
Reflective Coatings

Pavements occupy about 40% of urban land cover, with 75–80% black top roads, playing a critical role in urban connectivity and mobility. Solar energy is absorbed and stored in pavements leading to an increase in surface temperatures. Decreasing green cover is further contributing to rise in regional temperatures. Due to this activity, the city experiences urban heat island (UHI). This study presents a critical review of the literature on mitigation measures to combat UHI using reflective pavements with an emphasis on durability properties and impacts of tree canopy. The strategies with a focus on application of chip seals, white toppings, and coatings were discussed. Role of surface reflectance, including those from asphalt and concrete pavements, albedo improvements, and technological trends, application of waste materials, and industrial by‐products are presented. Also, urban tree shading systems’ contribution to pavement temperature and microclimate systems is presented. The review shows that the development of mitigation measures using tree shading systems can reduce the pavement temperature during daytime and increase human thermal comfort. The outcomes of this review provide a scope for future studies to develop sustainable and state‐of‐the-art engineering solutions in the field of reflective coatings and urban forest systems.

scholarly journals Microclimate Evaluation of the Hradec Králové City using HUMIDEX

2017 ◽  
Vol 47 (3) ◽  
pp. 231-246 ◽  
Author(s):  
Jaroslav Rožnovský ◽  
Tomáš Litschmann ◽  
Hana Středová ◽  
Tomáš Středa ◽  
Petr Salaš ◽  
...  
Keyword(s):  
Radiation Balance ◽  
Negative Effects ◽  
Environment Analysis ◽  
Surface Areas ◽  
Air Temperatures ◽  
Green Areas ◽  
Urban Heat ◽  
Surrounding Landscape ◽  
The City ◽  
Very High

Abstract Urban environment differs from the surrounding landscape in terms of the values of meteorological parameters. This is often referred to as the urban heat island (UHI), which in simple terms means higher air temperatures in cities. The cause of these changes lies in the different active surfaces in cities, which subsequently results in a different radiation balance. The higher temperatures, however, also affect the living conditions in the city and during very high temperature periods can have negative effects on the health of the city inhabitants. The results presented in this paper are based on measurements taken over several years at locations near Hradec Králové, which is surrounded by different surface areas. Environment analysis was performed using the Humidex index. The obtained results show that replacing green areas with built-up areas affects temperatures in the city, when air temperatures are very high they significantly increase the discomfort of the inhabitants. Differences in the frequency of discomfort levels are observed especially during periods of high temperatures, at lower temperatures these differences are not significant. Higher frequencies of discomfort are observed at locations with artificial surfaces (asphalt, cobblestones, concrete) and in closed spaces. In contrast, locations with lots of green areas almost always have the value of this index lower or more balanced. The results should therefore be a valid argument for maintaining and extending green areas in cities.

Real-life–type Problem Solving in Tourette Syndrome

2003 ◽  
Vol 16 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Shelley Channon ◽  
Sarah Crawford ◽  
Kian Vakili ◽  
Mary M. Robertson
Keyword(s):  
Problem Solving ◽  
Tourette Syndrome ◽  
Real Life ◽  
Type Problem ◽  
Life Type

scholarly journals Marginal Abatement Cost Curves for Water Scarcity Mitigation under Uncertainty

2019 ◽  
Vol 33 (12) ◽  
pp. 4335-4349 ◽  
Author(s):  
Karin Sjöstrand ◽  
Andreas Lindhe ◽  
Tore Söderqvist ◽  
Peter Dahlqvist ◽  
Lars Rosén
Keyword(s):  
Water Scarcity ◽  
Abatement Cost ◽  
Hot Water ◽  
Marginal Abatement Cost ◽  
Mitigation Measures ◽  
Cost Curve ◽  
Effective Measure ◽  
Trade Offs ◽  
Cost Curves ◽  
The Impact

Abstract As water scarcity and drought become more common, planning to avoid their consequences becomes crucial. Measures to prevent the impact of new climate conditions are expected to be extensive, costly and associated with major uncertainties. It is therefore necessary that policymakers and practitioners in both the public and private sector can compare possible mitigation measures in order to make economically rational investment decisions. For this to be successful, decision-makers need relevant decision support. This paper presents a novel approach of constructing marginal abatement cost curves for comparing water scarcity mitigation measures while taking the underlying uncertainties into account. Uncertainties in input variables are represented by probability distributions and calculations are performed using Monte Carlo simulations. This approach is applied on the island of Gotland, one of the most water-stressed parts of Sweden, to provide the first marginal abatement cost curve in Europe for water scarcity mitigation in which municipal, agricultural, industrial and household measures are compared. The results show that the agricultural measure of on-farm storage has the greatest potential to increase water availability on the island. Among municipal measures, increased groundwater extraction and desalination offer the greatest potential, although desalination is almost 25 times more costly per cubic meter. The most cost-effective measure is linked to hot water savings in the hotel industry. The approach presented provides a quantitative visualization of the financial trade-offs and uncertainties implied by different mitigation measures. It provides critical economic insights for all parties concerned and is thus an important basis for decision-making.

scholarly journals The Restorative Value of the Urban Environment: A Systematic Review of the Existing Literature

2018 ◽  
Vol 12 ◽  
pp. 117863021881280 ◽  
Author(s):  
Anke Maria Weber ◽  
Jörg Trojan
Keyword(s):  
Urban Environment ◽  
Real Life ◽  
Modern Society ◽  
Urban Environments ◽  
Natural Environments ◽  
Residential Areas ◽  
Research Focus ◽  
Urban Settings ◽  
Architectural Elements ◽  
Social Components

Background: Stress poses a major issue in our modern society, making restoration an important research focus. Restoration likelihood has mostly been observed in nature, which was compared with urban environments that have little restorative potential, eg, industrial areas. However, many people reside in and need to find restoration in cities. The main aim of this review is to summarize research that has focused on investigating restoration possibilities in urban environments and the environmental elements interacting with the restoration likelihood of an urban environment. Method: This review focuses on studies addressing the topic of restoration possibilities in urban settings in built and human-made natural urban environments. The studies were searched via Google Scholar, PsycINFO, PsycARTICLES, and PSYNDEX. All studies concerned with restoration in urban environments were included. However, studies concerned with nonoriginal data, solely investigating effects of natural environments or treating urban environments as a control for restoration in nature, were excluded from the review. Overall, 39 studies corresponded to the criteria and were included. Results: Natural elements in urban environments have a restorative potential and can increase the restorativeness of urban settings. Furthermore, built urban environments vary in their restorative potential, but promising results have been uncovered as well. Architectural elements, cultural, and leisure areas had a restorative value, whereas the findings on streets and residential areas differ. In sum, many urban locations can have restorative effects, but these effects may be influenced by factors such as cultural background, age, social components, and individual dispositions. Discussion: Certain urban environments hold a restorative potential. However, the literature on restoration in urban environments is still quite scarce and therefore has been of little practical use. Even though applying the findings to real-life environments is desirable, it might prove difficult, considering the overall sparse evidence. More research on the predictors of restoration likelihood (eg, social factors), generational and cultural differences, and comparisons between natural and urban environments is recommended.

scholarly journals Statistical modelling of spatial patterns of the urban heat island intensity in the urban environment of Augsburg, Germany

Urban Climate ◽  
2019 ◽  
Vol 29 ◽  
pp. 100491 ◽  
Author(s):  
Annette Straub ◽  
Katja Berger ◽  
Susanne Breitner ◽  
Josef Cyrys ◽  
Uta Geruschkat ◽  
...  
Keyword(s):  
Urban Heat Island ◽  
Urban Environment ◽  
Spatial Patterns ◽  
Statistical Modelling ◽  
Urban Heat Island Intensity ◽  
Heat Island ◽  
Urban Heat
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