what solutions to lower the temperature in the city?
The heat seizes Normandy this week. At the start of the week, temperatures reached 28°C in Caen, Rouen and Alençon. Faced with these summer temperatures, what measures are cities taking?
The heat wave, predicted by Météo-France at the beginning of May, continues this week. This Tuesday, the temperatures soared in Normandy. In Caen, Rouen or Alençon, 28°C were recorded. In these cities, where the heat is more felt, the heat islands raise the degrees of air and surface relative to the peripherals. The reason: the concentration of buildings and the lack of plants and permeable soils capable of absorbing solar energy. To reduce the heat in the city and make the temperatures more bearable, solutions are put in place. Example in Rouen, Caen and Alençon.
In Rouen, more than half of the territory is urbanized with too few parks and gardens. As proof, the Norman capital is below the national average in terms of square meter of greenery per inhabitant, with less than 32 m2 against 48 m2 on average in France.
For several months, a “renaturalization” plan, baptized “Rouen naturally” is set up by the town hall to “preserve and strengthen biodiversity and develop islands of freshness”, indicates the City. Its goal: to reach 30% of vegetated territory, against 17% today, explains Julien Goossens, in in charge of this renaturation in Rouen.
So, for some time now, schoolyards have been “debitumized” and vegetated and green spaces have been created. This Tuesday, May 17, an “urban oasis” was established in Rouen, that is to say a plant presence in the city, as well as a pétanque court, created “at the request of local residents”, specifies the town hall in a communicated.
By September, an urban canopy project on Allée Eugène Delacroix, identified as a heat island, is planned. Place Clément will also be revitalized. Rouennais and Rouennaises are consulted on this subject via a online quiz until May 29, 2022.
In Alençon, in the Orne, the fight against heat islands is received. An experiment, started in September 2020 is underway: that of eco-pavers.
These eco cobblestones are made from crushed shells developed by researchers at theESITC Caen. “The material formed is ultra-draining, it contains between 20 and 25% vacuum, water can flow in it, even faster than in sand, explains Mohamed Boutouil, research director at Estic. This is followed by a phenomenon of water evaporation which refreshes, by popularizing, a bit like a mist thanks to mini-fountains”.
This project Fresh-Ecopavers is part of the circular economy since “it responds to a local demand for recycling the shells available in large quantities on the Normandy coast.”
According to theGreen Cities Observatory 2020 in France, Caen is well placed in the ranking of the greenest French cities. She is ranked eighth. The city has more than 500 hectares of green spaces, or about 20% of its surface area, to which will be added, outside the agglomeration, the Grimbosq forest (475 hectares) and the Croisilles park (116 hectares).
However, Caen, like Rouen, remains below the national average in terms of green spaces per inhabitant with 47.6 m2 of green space available. Thus, to cope with the effects of climate change and to fight against the heat, the city is carrying out a “debitumization” campaign. More than 4 hectares will be debitumized then vegetated in the public space between 2021 and 2023, indicates the town hall for “contribute to the creation of an island capable of playing a regulatory role during heat peaks.”