ارزیابی اثرات توسعه‌ی گردشگری بر محیط‌زیست شهری (مطالعه موردی: کلان‌شهر تبریز)

Introduction
Nowadays, tourism, as one of the most dynamic industries in the world, is among the three employment-generating economic industries; one in 10 important jobs in the world has been related to the tourism industry. Over the past half century, this industry, with its exponential growth, has had a significant impact on the economic growth and dynamism and cultural exchanges of countries. As many experts have called the current century the century of tourism. The development of the tourism industry has brought many benefits to the host community, such as increasing employment, optimizing transportation, increasing residents' incomes, and protecting cultural heritage. However, overdevelopment of tourism has had negative effects such as degradation of the environment, resources, culture and society. In the meantime, one of the important negative effects of tourism development is in the environmental dimension. The relationship between tourism and the environment is a complex one, this phenomenon involves many activities that can have detrimental effects on the environment. These effects include water pollution from sewage, waste generation by tourists, environmental damage from land degradation, and air and noise pollution from airplanes and cars. Due to the importance of investigating the relationship between environmental indicators and tourism development, the purpose of this study is to investigate the environmental effects of tourism industry development in Tabriz metropolis. Tabriz metropolis with a variety of tourist attractions, religious attractions, historical attractions, military attractions, residential attractions and having a pleasant climate and favorable scenery, hot springs and mountains suitable for mountaineering and skiing (around the city), annually receives a large number Has been a tourist. In this regard, the study of environmental effects (positive and negative) resulting from tourism development and strategic planning in order to reduce the negative environmental effects is an inevitable necessity.
Methodology
The research method in the present study is non-experimental in terms of the purpose and degree of control, and in terms of the method of data collection, field and in terms of generalizability, it is a survey type. Also, the prevailing approach in the present study is analytical-exploratory. The statistical population of the study consists of experts and elites in the field of tourism in Tabriz, which due to the uncertainty of the statistical population, 90 people have been determined as the sample size through the Cohen method and snowball sampling. In the present study, first by documenting and interviewing with a statistical sample, the environmental effects of tourism development are identified, then by questioning the sample size and using t-sample and Friedman tests and factor analysis model in SPSS software environment, the effectiveness of these factors has been reviewed. It is noteworthy that in order to determine the statistical sample size, Cohen's formula was used at a 95% confidence level.
Results
Findings indicate that the most positive effects of tourism development in Tabriz metropolis belong to the variables of environmental improvement and natural landscapes, promoting sensitivity and awareness of ecological systems and increasing environmental awareness and improving environmental and ecological quality, respectively, the numerical average, they are 4.78, 4.25 and 3.78 and their average ratings are 14.49, 13.32 and 10.67. Also, the least positive effect was related to the variables of creating new patterns of energy supply by nature and giving importance to the local community to natural resources and protection of the urban environment. Also, according to the extracted results, it can be said that the negative environmental effects of tourism development in Tabriz metropolis can be classified into 4 main factors. In the first factor, the negative environmental effects of tourism development are loaded with 6 variables. This factor, called environmental degradation, is the most important negative environmental effect of tourism development in Tabriz metropolis, which with a special value of 7.567, explains 28.756% of the total variance. The highest factor load (0.981) in the first factor belongs to the variable of degradation of natural landscapes (due to excessive creation of accommodation and catering facilities). In the second factor, with a special value of 4.651, 5 variables are loaded. This factor explains 20.40% of the total variance and its most important variable is the increase of waste in the natural environment with a factor load of 0.891. According to the variables loaded in this factor, the name of this category can be named as increasing environmental pollution. The third factor, called the destruction of man-made landscapes, has three variables, with the highest factor (0.794) belonging to the variable of the disappearance of traditional architectural style due to the development of modern housing. This factor with a special value of 3.871 explains 14.661% of the variance. Finally, in the fourth factor or damage to ecosystems, which is loaded with 2 variables, the highest factor factor is related to the incidence and prevalence of new diseases (0.769). This factor explains 10.847 percent of the total variance and its specific value is 2.119.
Conclusion
One of the main topics discussed by experts is the application of the approach of environmental development and sustainable development. Today, the close relationship between tourism and the environment and the importance of the environmental planning approach and sustainable development planning have increased attention to these approaches. Tourism can have many positive and negative effects on the environment. Studies in this field have shown that the negative effects of tourism are much greater than its positive effects. The findings of the present study show similar results by examining the environmental effects of tourism development in Tabriz metropolis. Based on the results, it can be said that several negative environmental effects of tourism development in Tabriz metropolis have been shown, the most important of which are the destruction of natural landscapes, increased waste in the natural environment, uprooting plants and damage to vegetation, damage to ecosystems, extinction Traditional architectural style due to the development of modern housing and damage to buildings and monuments in the city. However, the development of tourism has also had positive environmental effects, the most important of which are the improvement of the environment and natural landscapes, the promotion of sensitivity and awareness of ecological systems and the increase of environmental awareness and the promotion of environmental and ecological quality.