عوامل مؤثر در مکان‌یابی ساختمان‌های بلندمرتبه با تأکید بر پایداری محیط‌زیست (مطالعۀ موردی: شهر قزوین)

As a product of population growth and increased urbanization as well as insufficient land for construction, high-rise construction and vertical spatial development have increased unprecedentedly during the recent decades. This type of construction, considering its characteristics, despite its positive effects, faces restrictions and threats which result in several difficulties including heavy traffic, remote workplace, environmental pollution, excessive urban development on farmlands, and wasting time. In most cases, physical development is surpluses to population growth. Today, locating high-rise buildings is a necessity which is assigned much importance in urbanism due to the environmental issues and climatic conditions of an area. The case studied in this paper is the city of Qazvin. The purpose of this paper is to analyze the effective factors in location of high-rise buildings with emphasis on environmental sustainability in the city of Qazvin. The research method is descriptive- analytical and based on application and development. Results from TOPSIS model used in this study show that there is no pattern for location of high-rise buildings in Iran and disorganized criteria provided regardless of urbanism or effective factors lead to environmental degradation. Results also show that economic, environmental and physical factors and land use (0.695, 0.457 and 0.405) are in first to third place indicating their relatively high importance compared with other factors. 
Introduction
Construction of high buildings has always provoked controversy among architecture and urbanism scholars. High- rise buildings were constructed in order for optimum utilization of land in metropolitan centers but gradually, as cities expanded, more necessity for buildings in other urban areas arose. 
Considering its approach, this study is applied- developmental with a descriptive- analytical method. The data was collected using library method and various statistical sources including nine main components; economic, managerial, socio-cultural, aesthetical, environmental, etc. 
Methodology
According to the method, problems are handled systematically and their different components are analyzed. Effective variables, acquired through descriptive and library methods, are identified, indicators appropriate for component analysis are set and variables are studied using TOPSIS. 
Results from TOPSIS indicate that from nine studied components, economy is in the first place. Large size and less density of Iranian cities resulted in the use of suburban agricultural lands, porous urban land and harmful economic and environmental effects which impose heavy loads on government and citizens. Therefore, optimal use of available resources in the cities is necessary (Azizi, 2004: 137). 
Result and Discussion
Accordingly, the relationship between density, land price and housing is the main economic aspect of urban density standards. Due to the important role land price and housing play in house price, fluctuations in land price has a great effect on the area of land and house infrastructure and as a result building density. According to experts and elites, second component is the environment, so that, during recent decades, environmental sustainability has been considered as a sustainability aspect in high- rise construction which, according to some researchers, has been neglected as a result of land conditions and environmental problems occurred especially in third world countries. Land use and fabric are in the third place. Traffic is fourth component indicating its effect on locating high-rise buildings, since proper access is an important indicator of urban space utility in this variable.
Due to favorable weather condition and view, quiet space and adjacency to business areas, high- rise buildings of most cities including Qazvin are demanded a lot. Provided that there is no traffic and with normal speed of cars, the distance and time to pass major access routes for the city of Qazvin is reasonable.
Management is fifth component which can play major role in locating high-rise buildings, since proper planning and map for construction of these buildings depends on management which is very important to construct this type of buildings. 
Society- population component is in sixth place according to which the density in high residential buildings in social aspects is discussed. High population density in space and high- rise buildings have negative effects including reduced human activities and resultant increased boredom and increased isolation which indicate reduced satisfaction levels from high-rise buildings forms and sizes .
Cityscape is seventh component in which the function, identity and beauty of buildings are very important. In terms of function, Lynch believes that an open landscape of public buildings, which lead to more relationship between people, can be welcomed by public, otherwise they will be ignored. Hence, the function of such buildings in cityscape is important. 
By aesthetical aspect, physical aspect of buildings in cityscape and by physical aspect of high-rise buildings, their form and effect on cityscape are intended. 
Climate is in ninth place and the type of climate is discussed in it since position and direction of buildings are very important. 
High-rise construction has been used for over half a century in metropolises. Building high residential buildings and towers in high and semi-high and also attached and detached forms in various cities prove the claim. Qazvin was no exception and towers have been built in various parts of the city with different purposes. Rapid and uncontrolled growth of population followed by excessive demand for house as well as preventing horizontal development of cities made high-rise building a solution to land problems.  
Conclusion
Results show that there are effective factors in locating high-rise buildings including; socio-cultural, fabric and land use, transport, climate, economy, cityscape, population and environment. Findings showed that economy (0.695) was the first and most important component considering its corresponding costs. Environment (0.457) was second. A sustainability aspect in high-rise construction is considered in this component which has been ignored, according to some researchers, due to land conditions and environmental problems caused by human activities especially in metropolitan areas and more attention is required when implementing urbanism plans, since some scholars believe in environmental sustainability as the main goal of sustainable development. Fabric and land use was in third place (0.405). Therefore, these three components had the highest impact and importance compared to other components that represents their priority in locating high-rise buildings to minimize scale-based economy, land saving and other problems.