to combat the heat in cities, it’s time to create “islands of coolness” and plant more plants

by times news cr

2024-07-19 13:31:51

It is difficult to expect that the weather will cool down in the coming decade, so a natural question arises as to what we should do in our cities to avoid such heat islands and make the heat less bothersome to the residents. Prof. Kaunas University of Technology Faculty of Construction and Architecture (KTU SAF) researcher speaks on this topic. Jūratė Kamičaitytė.

– What measures must cities take now to make it easier for them to survive heat waves in the future?

– There will not be one answer here. To achieve the best result, a complex (holistic) approach is needed, which covers all the systemic layers of cities, starting with man-made structures and ending with the natural natural environment of cities that needs to be nurtured. Let’s say that in order to reduce the temperature in cities, it is necessary to design as few hard surfaces as possible, which heat up quickly in the summer. Reduce asphalt or paved surfaces.

Priority should be given to soft, water-permeable surfaces, leaving room for grass to grow. Of course, you should also plant as many trees and shrubs as possible that provide shade. Vertical planting, climbing plants help prevent the walls of buildings from overheating. Water bodies also help to reduce the temperature of urbanized areas.

As for the special measures that are already implemented in many cities around the world, it is the creation of parks as “islands of coolness”. They are created by pre-modelling the variety of plant species in the area, arrangement, moisture regime, movement of air masses, assessment of wind direction and other factors. Such well-planned parks are not only fun to be in, but the cooler air from inside the park can reduce the air temperature downwind by hundreds of meters, and sometimes even by several kilometers. This is especially true for densely built-up cities.

– How do the solutions for old towns, Soviet-era residential areas and newly built suburbs differ?

– There is usually a lack of greenery in old towns. We will find them in the closed spaces typical of old towns inside the blocks, but not in the streets. They are usually small, cozy, “human”-scale streets paved with stones, just like the squares of the old towns.

There is usually nowhere to plant trees or sow grass here, so drinking water fountains, plants in pots, green walls, small architectural objects with integrated green infrastructure solutions and other small-scale green interventions that do not change the spatial basis of the old town would be useful.

Soviet-era residential areas, on the contrary, have large areas of green spaces, whose temperature reduction efficiency depends on the purposeful management of such areas in accordance with the already mentioned “cool islands” design principles. For these neighborhoods, it is the most difficult to balance the growing demand for parking areas and denser construction with green preservation and purposeful planning.

The problem of newly built areas in the suburbs is the lack of any public green spaces, the construction of large areas with single-family houses, and the lack of social infrastructure. Here, it is necessary to pay more attention to the greenery of streets and individual plots, to try to create green public spaces, to rethink the design principles of individual house blocks, preserving valuable natural elements and not building everything to the maximum.

– What would a section of a street perfectly adapted to a hotter climate look like?

– First of all, it must be a green street, where trees provide shade and prevent hard surfaces from heating up. Surface rainwater collection systems should not be forgotten: planted rainwater collection ditches, rain gardens, which would not only be useful for rainwater management, but would also increase the surface area of ​​soft, water-permeable, less heated surfaces.

– What measures could be installed by the residents themselves, and what should be done at the level of municipalities or the state?

– Residents themselves could contribute to green infrastructure development projects by designing their yard, they could reduce the areas of hard surfaces, plant their yards.

At the state and municipal level, design standards, methodologies for evaluating project solutions could be prepared, not the widening of streets but greening could be initiated, the corresponding transformation of green public spaces using their potential as “islands of coolness”, the protection of the ecological potential and naturalness of the coasts of urban water bodies, etc., care must also be taken to educate the population and increase ecological awareness.

– In southern states, you often see parking lots that are covered with canopies with solar power plants or simply planted with trees. Which practice would be more suitable in Lithuania?

– Both practices are suitable and sometimes it is very important to remember the principle of reconciling the dilemma when the use of renewable energy is combined with green infrastructure solutions. In this regard, private businesses could show a lot of initiative by equipping their parking lots with solar power canopies or by planting them.

– When traveling in hot countries, it is often surprising how their old buildings keep cool even in the hottest time. What technologies/materials lead to this?

– This is often determined by the cultivation of traditional construction technologies and their creative use in modern buildings. There is such a direction of building design – bioclimatic architecture. This design concept considers the optimal relationship of the building and its systems with the contextual environment and the systems operating in it as an essential criterion for the quality of the building’s architecture.

In such buildings, microclimatic comfort is achieved through architectural forms, elements, materials, structures, avoiding dependence on mechanical systems. Often we just need to look back and re-evaluate our traditional construction techniques, rather than trying to invent something new or copy the architectural solutions of other countries. Clay, wood, and stone, which have been used in construction since ancient times in our region, are perfect for protecting indoor spaces from overheating.

– KTU SAF, together with partners from Birštonas, participates in the international “GreenInCities” scientific project, which examines precisely these questions. What jobs are there?

– The goal of this project is the implementation of ecological innovations in cities in order to mitigate the consequences of climate change. During the implementation of the project, methodologies, tools, urban planning and design concepts will be developed and tested, focused on innovative solutions for the “greening” and renaturalization of cities, in order to achieve the regeneration, conversion, rehabilitation and pollution reduction of urban areas. This, of course, is related to the processes of climate warming and increasing the resistance of urban systems to their effects.

The project results are aimed at the principle of co-creation, when all interested parties participate in the creative process: scientists, architects, urban planners, local government representatives and urban communities.

Currently, KTU scientists participating in the project are preparing methods and tools for the implementation of these goals in Lithuanian and foreign cities participating in the project.

2024-07-19 13:31:51

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