this large asphalt surfaces, traffic, pollution and lack of green spaces they make cities react poorly to summer heat. Urban design determines microclimate where we live, and therefore changing it allows us to create conditions that allow us to better cope with high temperatures.
A tool to improve thermal comfort, bioclimatic urbanism, taking into account the sun and the wind to design public spaces of cities such as streets and squares. Bioclimatic strategies integrate three variables: wind, sunlight and humidity. In a big city, bioclimatic measures in urban design should include the following elements to combat heat:
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Shady areas during central hours of the day.
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Spaces that create wind channels for breezes.
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Areas with fountains and layers of water.
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Areas with deciduous trees with high evaporation.
Adapt to both heat and cold
Beyond the heat waves of the summer of 2022, with record temperatures, we should also consider the cold winter situations. Designing flexible strategies is crucial.
in cities like Madridfor example, there are months of the year that are less warm than overheated, so it is important to get sunlight on the streets and squares in winter and shade in summer. On the other hand, the lack of thermal comfort during the central hours of the day due to high temperatures can be compensated by considering wind and evaporation.
Below we collect the main strategies for: creating bioclimatic oases which improves summer conditions in the city.
1. Shading of streets and squares
given the situation high temperature emergencypublic spaces can be designed with trees or elements that help provide shade by placing textiles on the streets.
There is an opportunity to shade public spaces with pergolas or photovoltaic fabric canvases that add to the shade the possibility of generating photovoltaic solar energy.
2. Wind in urban design
The first step to take advantage of the wind I know where you come from in the city in the summer. Maps that help to know the wind speeds and directions of the place are now available in real time and data can be requested from meteorological institutions. We can see how it is on the map that comes before these lines. on the outskirts of Madrid The wind speed is higher than inside, almost three times: 3-4 km/h (blue colours) to 12-14 km/h (green colours). The lines of the summer winds of the previous chart help us determine:
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Natural ventilation corridors if the main streets carry the prevailing wind direction.
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Deciduous trees and shrubs placed in rows parallel to the summer winds to favor wind channels.
3. Increased vegetation in the city
increase in Park area It is the key to improving the thermal conditions of summer in the city. Thanks to the large number of species already accustomed to the climate in the city, it is necessary to look for variation between size, evapotranspiration.
For example, in Madrid, the city council reviewing its urban regulationsSince 1997, there have been important changes and transformations that should be included in the General Zoning Plan. One of his contributions is the structuring of the concept of the green factor:
The green factor is a numerical parameter aimed at improving sustainability, thermal and bioclimatic comfort conditions and the urban environment of the city.
The exact calculation of this indicator, at the moment, is considered where its existence. vegetation on the trees in the streets, inside facades, on roofs and in public space.
4. Soil permeability
Sidewalks and driveways should be blocked almost waterproofWith close to 90% flow. The goal is to maximize the use of permeable coatings. For example, in Madrid, the minimum parameters set by the Regulation on the Management and Effective Use of Water in the City of Madrid will be taken.
The ideal is to have a piece of water that can seep into the soil. Composition of materials, slopeThe amount of precipitation and the presence of vegetation are the factors that condition the final runoff factor. One suggestion is to design sustainable drainage soils.
The aim is to increase the permeability of the streets. damping It allows the use of runoff water to create a favorable microclimate and contribute to the growth of vegetation.
5. The color of urban sidewalks
Color of surface materials is important for diffuse solar radiation reflected on them and stipulates the thermal well-being of passers-by. In general, it is always recommended to pave sidewalks and even driveways in light colors (asphalt is already available in a wide variety of colors).
The aim is to increase the albedo (light colours) of the horizontal surfaces on pavements and roads, reduce the surface heating of the streets and indirectly improve summer comfort conditions.
Thermal oasis in the city
Purpose of strategy to design urban thermal oases Creating a suitable microclimate for as many days of the year as possible.
All the strategies described in these areas will be combined: ponds and fountains will be installed and deciduous trees will be placed according to the prevailing wind direction in summer to create wind channels. All this is complemented by light colored pavements and permeable floors on at least 75% of the total floor.
The World Bank estimates seven out of ten It will live in urban areas by 2050. Adapting cities with bioclimatic strategies is essential in the face of increasingly common extreme weather conditions due to climate change.
Source: ecovant.