Climate Parameters, Heat Islands, and the Role of Vegetation in the City
Abstract
Climate has a strong influence on urban planning and also plays a fundamental role in soil composition affecting the character of plants and animals. The climate is a combination of different meteorological factors that characterized a specific region over a specific time. The movement of the Sun and Earth inclination toward it is the most important factors which determine the characteristics of the climate. The global movement of the air from equator toward poles and vice versa influences also drastically the climate change. In this section are also included breezes. Also air relative humidity plays an important role shaping the climate. It plays a very important role in cloud formation. The built environment can influence the urban climate of the city through height, form, and applied building materials. Building form and shape, building materials, openings in the façade, and their orientation often are determined by climate parameters. Urban density, directions, and street network and their shape are related to the climate change, apart from topography. Density of urban structures produces important effects on the microclimatic conditions in external spaces. The bioclimatic behavior of each type of outdoor spaces depends on the relationship with its surrounding elements. The city of Tirana is included in Mediterranean climate characterized by hot dry summers and mild cold wet winters with high daily thermal excursions. All of the countries bordering the Mediterranean Sea benefit from the Mediterranean climate. Specifically spotted, Tirana is part of Mediterranean coastal zone (<22 °C in temperature) with an annual temperature of 15.3 °C. In the inner city can be found areas with high pollution, which normally contain a high percentage of business and industry, settlements, and traffic, so-called “sealed” areas. They constitute “hyperthermic areas” or “heat islands”. The term “heat island” describes built-up areas which are hotter than nearby rural areas. Heat islands can affect communities by increasing summertime peak energy demand, air-conditioning costs, air pollution, greenhouse gas emissions, heat-related illness and mortality, and water quality. The aim of the bioclimatic design is also the reduction of the heat-island phenomenon. The use of materials with different energy absorption capabilities and integration of green spaces into urban life is important. The vegetation effects on microclimate and in the built environment are present. Trees are necessary and indispensable to human life. They provide shelter for us, provide food, and their fibers cloth us. Implementation of the green belts in the city is one of the strategies in order to reduce heat-island effect. Vegetation also can provide a deep feeling of attachment to certain places and trees which are part of it. The use of trees avoids monotony and ensures diversification. They play a crucial role creating microclimates which influence the thermal comfort of people reducing heating or cooling loads. Vegetation also creates cooler microclimates around the building through evapotranspiration, reduces wind speed, regulates humidity, and reduces temperature. It is observed that tree species have a greater influence on humidity than on temperature. Trees can also absorb and reduce the reverberation time of the sound, behaving as sound buffers. The benefits of tree plantation in the inner city are enormous and they can’t be neglected.