Water body effect on microclimate in summertime: A case study from Pécs (original) (raw)
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Water Bodies an Urban Microclimate: A Review
Modern Applied Science, 2015
In urban areas, water bodies have a positive effect upon microclimate of the surroundings with the relative cooling impact it has on evaporative procedure. Hence, evaporative cooling might be one of the pretty efficient methods of passive cooling for urban spaces and buildings. Differences in temperature between the urban space and the non-urban space which surrounds, is dubbed UHI (Urban Heat Island) effect. Water bodies have also been proven to be influential methods of decreasing urban temperatures. A water body temperature is capable of being lower than the surrounding urban environment around 2 -6 °C. According to these findings; one may conclude that the rise of evapotranspiration in cities, that has roots in vegetation and water body, can efficiently mitigate the influence of the urban heat island. Unfortunately, the effect that water bodies can have upon urban temperatures has not been thoroughly assessed in previous studies, specifically the difference between the daytime and night time influences of water bodies, and the matter the how urban design may be in influential in moving the cooling influence from the water bodies toward the city. This paper provides a theoretical background for the problem and reviews the related literature.
2016
The thesis addresses the contributions of urban geometry under tropical climate in the Melaka city, Malaysia and their benefits toward optimum cooling effect of water body modification. The aim is to examine quantitatively the potential of the cooling effect from combination of water bodies and street geometries with the development of comfortable microclimate conditions at street level in the city environment. Main methodologies phases which is field measurement were conducted and computer simulations were developed in order to achieve the aim and objectives of study. Environmental Visual Image Microclimate software (ENVI-met Ver. 4.0) was used to predict the impact of modification according to the proposed hypothetical urban geometries were simulated with various street aspect ratio (building’s height / street’s width) where the ratio is equal to 1, more than 1, and less than 1, and river width equal to 18, 36, and 54 meters. The proposed urban settings in Melaka city that resulte...
International Journal of Environmental Science and Development, 2020
Water features that are found in the urban zone influence the micro-climate atmosphere of the encompassing regions positively when natural cooling from the evaporative process is required during the hot radiant day. Consequently, this paper is focused on the influence of the wider water body on air, surface and physiological equivalent temperature at multiple scenarios at a pedestrian level. Where scenarios are based on the different materials being used to construct the footpaths and different width of water body of Malacca town. The climate data includes air temperature (Ta), relative humidity (RH) and wind velocity (v), globe temperature (Tg) and surface temperature (Ts) which were all continuously measured within the Malacca water body area at different scenario via field investigation through the instrument. The RayMan software package was used to elucidate the physiological equivalent temperature (PET) of the six scenarios. The results confirmed the bare red clay pavement materials that are close to adequately wide water body is the best scenario for maintaining low air and surface temperature as well slightly warmer comfort range at the pedestrian levels for creating suitable physiological equivalent temperature. This measurement activity seeks to provide an understanding in the field of climatic urban design, and the potential of utilizing water bodies (water cooling effects), as an urban design tool, about minimize the profound effects of extreme air and surface temperature on human comfort levels (PET) under the hot and humid condition in Malacca Town. Index Terms-Pavement material, surface temperature, waterbody, physiological equivalent temperature (PET), Malacca town.
International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies, 2020
In the current growth of urbanization, problems especially anthropogenic heat emissions are emerging. Urban Heat Islands (UHI) are one of the major causes of environmental problem and it exacerbates the cities' living environment heat conditions critical to human health. Various factors affect the urban thermal environment, which is closely linked with UHI as well as the outdoor thermal comfort. These factors include buildings density, urban landscaping and water bodies. Water bodies are one of the significant components of the core surface. Water influence the urban thermal environment of the surrounding through its cooling effect, either through evaporation or heat transfer between the air and water. This review paper comprehends the factors that facilitate the water bodies cooling effect in order to achieve urban cooling island to mitigate UHI. Disciplinary: Architectural Sciences.
This study explores the possibility of urban water body induced city cooling in the Sri Lankan context, with special reference to the Beira Lake, Colombo. The research method utilises the computer simulation tool ENVI-met to explore o The effectiveness of an urban water body in influencing the microclimate. o A water body in comparison to an urban green space of similar magnitude. o Microclimatic and thermal comfort changes within selected sites of specific orientations, encompassing existing and simulated morphology. o The effect of, and on the wind pattern around the lake in a holistic design scenario. The simulated results and analysis were limited to the peak time of the day of 14.00hrs of a single day in March. Conclusions show that contrary to established thinking the Beira Lake has a negative effect on the thermal comfort, yet will facilitate better wind and evaporative cooling potential in the immediate surroundings.
Modeling the influence of vegetation and water pond on urban microclimate
Solar Energy, 2006
The beneficial influence of trees and water ponds on summer comfort in urban spaces was studied experimentally in situ and in wind tunnels but the modeling needs further development to become effective in practical applications. This paper introduces a numerical approach based on coupling the CFD model of airflow, in which the influence of trees is considered as source terms, and the radiation exchange, completed with thermal conduction. The CFD, radiation and thermal conduction models use the same discretization grid at their common boundaries. The model was used to estimate the influence of trees and water ponds in a real town square. Comparison of results between two situations, with and without vegetation and water pond, indicate that surface temperatures are reduced in presence of trees and the comfort is improved.
Effect of water features on the microclimate of residential projects in a hot-arid climate
Acta Scientiarum Polonorum, 2022
This paper investigated the effect of water features on thermal comfort in a central open space of a residential project in a hot-arid climate. A crowded urbanized area in Baghdad was chosen as a case study a city. The methodology relied on a simulation method using ENVI-met 4.4.5 software to create a model of a residential project and obtain the levels of the predicted mean vote as well as four parameters associated with it. These parameters included, air temperature, mean radiant temperature, horizontal wind speed, and relative humidity. For the purpose of comparative analysis, four types of surfaces were modelled, a surface with a water feature, a vegetated surface, a concrete surface, and a combination of green and blue surfaces. The simulation results showed that a water feature can significantly decrease the levels of the predicted mean vote (PMV) index. It was even more effective than a vegetated surface in increasing thermal comfort levels in the microclimate of a residential project in a hot-arid climate.
COUPLING THERMAL MASS AND WATER SYSTEMS AS URBAN PASSIVE DESIGN IN HOT CLIMATES
The impact of water in buildings is studied as a combination of vertical walls and horizontal pools that creates a combined passive cooling system for public spaces in hot climates. The paper draws from traditional water-based systems principles and forms in Mughal architecture, with the aim of studying its thermal cooling impact using CFD. Due to rapid urbanization in cities, there is a heightened demand for cool, dry comfort yet energy use can be saved by focusing on the cooling of workplace spaces while public areas are naturally cooled to reduce the carbon lock-in effects of cities. Selected sections of 16 th and 17 th century Mughal complexes are analysed in terms of its combination of both thermal mass (thick, high density walls), water pools, water walls and channels. The study initially looks at water to ground ratios of different Mughal gardens and enclosed courtyards, the overall integration of pools, channels, and water walls in past forms. More importantly, it analyses the impact of the coupling of thermal mass and water elements in a passive system within an infrastructure to achieve almost zero reliance of non-renewable energy for its public areas.
Journal of Building Materials and Structures, 2018
The present study aims at testing the influence of the urban morphology on the external weather conditions and the urban microclimate by treating quantitative aspects of the outdoor thermal comfort. This is based on a site investigation aims at studying the correlation between the geometry of the street, its orientation and the evolution of the physical variables: air temperature (Ta), Mean Radiant Temperature (MRT), Relative Humidity (RH), Wind speed (Ws). The measures were the subject of a campaign carried out in the urban fabric of the ksar of the red village in the wilaya of Biskra in Algeria. The objective is to define the most efficient urban geometry in term of summer thermal comfort by studying the real impacts of the urban form on the solar control and microclimatic conditions. The evaluation of the thermal comfort in these external spaces is carried out by analyzing physiologically equivalent temperature (PET) values calculated by Rayman Pro 2.1 software based on the measu...