Scientists relied on the cooling effect of soil against warming in cities. A study in Hamburg reveals the temperature difference between green areas and concrete areas. Undoubtedly, one of the most important problems brought about by urbanization in the world is concrete. An area the size of 50 football fields is concreted, asphalted and opened for construction in one day in Germany. Especially in cities, the effect of concretization makes itself felt in the climate. As the number of buildings rising in the city skyline increases, the weather gets warmer. While those in the city center are overwhelmed by the heat, a light breeze breathes in the green area a few steps away.
Scientists have revealed that the temperature difference between the city center and the outside of the city can reach three degrees. Building walls and asphalt absorb and store heat during the day and give it back out at night. In the green area, the ground is not covered with concrete or asphalt. The soil is moist. The water in the soil evaporates, causing the small park to cool a bit. This connection has prompted scientists to find the answer to the question "How much can soil reduce the effects of climate change?"
The cooling effect of the soil
Annette Eschenbach, Professor of Soil Conservation and Soil Technologies at the University of Hamburg, who led the research team, says:
“Especially in cities, there is already a problem of overheating at night. This also applies to daytime. Due to climate change, this will increase even more, as the temperature rises, the precipitation will decrease. The question for us was the impact this had on people.”
Eschenbach, who carried out the research project to seek an answer to this question, focused on the cooling property of the soil and compared various soil types in this regard. The research team installed measuring devices in various parts of the city and measured temperature, wind speed and humidity in the air.
The importance of groundwater level
Eschenbach states that they have placed sensors at various depths, from 5 centimeters deep directly below ground level to 1 meter 60 centimeters deep, and adds: “These sensors measure soil temperature, water amount and water retention curve. Water retention is very important in analyzing the question of how much of the water can actually be used.”
Eschenbach emphasizes that in the light of the results obtained from the measurement values, they see that the areas are dried at different densities and that this is a situation dependent on the groundwater level.
“Parks are cooler”
The moist soil is fed from below, from groundwater. During periods of low rainfall, it dries more slowly than soil where the groundwater level is lower. The researchers also found that moist soil measurably cools the surrounding air compared to dry soil. As a result of measurements made throughout the year, it was determined that the air in the park was half a degree cooler than the densely populated neighborhood right next to it.
“This means that parks in the city are of great importance for the local climate. Creating more parking spaces is always right. But this was known before our project. But after this project, we can add: It is even smarter to set up the parks in humid areas. Because then the cooling function is better provided.”
Source : news