Impact of Vegetation on Thermal Conditions Outside, Thermal Modeling of Urban Microclimate, Case Study: The Street of the Republic, Biskra

Urbanization can only grow because of population growth and ongoing population movements. Expressing interest in urban microclimate on the thermal conditions outside is very important in this period of warming climate began. The presence of trees leads to cooler areas in the urban environment. The parks contribute significantly to the reduction of air temperature. Three specific effects of vegetation shade, evapotranspiration and the effect of natural ventilation. In contrast to mineral surfaces, green spaces only store little heat and humidify the atmosphere through evaporation important, thus greatly reducing the air temperature. Evapotranspiration is defined by the loss of water to the atmosphere by evaporation and transpiration. The urban development projects can significantly change the image of a neighbourhood or town. In the city, the microclimatic component can unite several actors (architect, planner, landscape, political, developer, engineering firm,) advocating an interest in energy savings for the adjustment of thermal conditions of the urban space and the improvement of life. These components have largely been put forward when we discussed the relationships between vegetation and the city. Nevertheless, as we shall try to demonstrate this aspect in the plant site (garden 5 July - checker colonial) leads us to illustrate clearly the benefits of vegetation in urban areas. The trees act as a mask to sun and wind and as a source of control the air temperature and the temperature of the surrounding surfaces. The effectiveness of these spaces depends on their density, shape, size and position. Mitigation of air temperature in the presence of tree can be explained by the decrease in surface emperature that induces a lower air temperature [1]. To know the real impact of vegetation on air temperature, thermal modeling work was necessary, was carried out on the street of the republic located in the checker colonial, flanked on one side by the garden 5 July, and another side by buildings, located in the center city of Biskra (Algeria) and spread over a typical summer day with a three dimensional numerical model called “ENVI-met”.