عنوان مقاله [English]
Climate change is one of the brightest examples of human activity. With changes in their environment, humans create conditions that can change the climate and temperature of the air. The clearest indication of human impact on the climate can be seen in cities. Urban development can change in the local and regional climate. The most important impacts of climate change in cities include the urban heat islands. It is well known that urban advancement and development causes climate change, including the creation of a city heat island in metropolitan areas. In fact, urban heat islands are separate units whose temperatures have increased throughout the urban areas and the warmth of which has increased in recent centuries. Despite the heat island, the number of warm days per year also increases. The urban heat island was first introduced in 1819 by Lockheavard in London. Subsequently, this phenomenon was recognized in small and large cities around the world. There are several reasons for the heat island. The main reason for the increase in night heat in buildings in flat, overnight and evapotranspiration nights in urban areas is generally due to asphalt and cement used in urban areas. Modern urban areas usually have dark and no-cost areas over the suburbs. This difference affects the climate, energy consumption and urban habitability. In sum, the dark levels and the lack of vegetation will warm the air of urban areas, which will result in the creation of urban thermal islands. In a summer afternoon (in the air), the weather in a city is about 2.5 degrees Celsius warmer than the surrounding rural areas.
The city of Tehran has faced the problem of the thermal islands in the last few decades, due to the concentration of population and economic activity in it. From 1303 to last year, the minimum temperature in Tehran was negative by 15 degrees, which has now reached a negative 5 degrees due to climate change, which means a rise in Tehran's temperature, which has led to a decrease in precipitation and a temperature increase of 2 to 3 degrees. . According to meteorological statistics during these years, the minimum temperature of Tehran and maximum temperature in Tehran have increased and precipitation has decreased by at least 10%. These are the result of climate change due to the excessive use of fossil fuels. In Tehran, about 100 million liters of fossil fuels consumed at a time when most of these fuels become carbon and pollutant gases. Hafteir Square, Enghelab Square, Shoosh Square, Azadi Square and Ghaytrieh Areas are the thermal islets of Tehran. Considering the presence of thermal islands in Tehran and the negative effects on urban society, it appears that using adaptation strategies and reducing the impact of urban planning and management in order to increase the resilience of urban communities seems to be appropriate. The purpose of this paper is to explore the effects of adaptation strategies on urban heat and waste in Tehran. To do this, we first understand these strategies and then, using the viewpoint of experts and managers, the feasibility of their implementation in the city of Tehran has been addressed.
This research has been conducted on the basis of an analytical descriptive method and its type has been essentially applied. In the first part of the descriptive study, theoretical foundations and scientific literature have been studied and in the analytical section using the fuzzy verbal technique (FMCDM), the feasibility of using strategies Adaptation and reduction of impact against urban islets. In order to implement this technique, a questionnaire designed by experts is being developed. Many experts often cannot use precise numerical values to express their opinions. Therefore, the use of verbal assessments seems to be more realistic. Grades can be transmitted through verbal data such as (very much, much, etc.). ) To fit the theory of fuzzy sets seems to be more appropriate. Therefore, the problem under consideration is a fuzzy multi-criteria decision making (FMCDM) problem. The statistical population of the research is urban planners, designers and managers, a method for determining the sample size of a snowball model.
Results and discussion
In order to rank the reduction strategies in terms of the possibility of implementation, the results of the questionnaires were analyzed and the results were obtained based on verbal fuzzy method and digitalization of the numbers. According to the results of the analysis of the questionnaire by fuzzy method, the strategies for changing the colors of the roofs and changing the colors of the urban walls into more reflective colors can be implemented more than other strategies. The strategy of using modern technologies in the architecture of buildings with the least possible use of cooling systems and the use of green roofing technology for residents in the region also have the least possibility of implementation.
Adaptation strategies have been less feasible due to their long duration and the need for more planning and budget than some of the strategies to reduce the impact. Civic education strategies aimed at adapting to more temperatures, promoting and educating citizens in the field of saving energy and gas, using methods of attracting participation of citizens in this problem from the possibility of implementation more than other strategies They have adaptation.
According to experts, it can be acknowledged that whatever strategy has been considered to be easier to implement, it has gained more privilege in implementing ranking, while strategies that implement stringent conditions And the need for planning and budget has been remarkable, it has got lower ratings in terms of implementation. In general, it can be concluded that the effect reduction strategies are more likely to be implemented in Tehran. Of course, among the reduction strategies, there are some issues that due to the high cost and the need for specialized work and the appropriate field of study, some of the adaptation strategies are in the possibility of implementation in the lower ranks.
Keyword: Feasibility Study, Heat Islands, Adaptation, Mitigation, Tehran Metropolis