Ms Zahra Sharghi, Dr Mostsfs Basiri, Dr Mahsa Faramarzi Asl,
Volume 0, Issue 0 (3-1921)
Abstract
The basic purpose of this research is to reveal the physical development process of the new city of Sahand, as one of the new cities of the country, using Landsat satellite images during the statistical period of 1401-1373. In this regard, satellite images required for 4 statistical periods of 1373, 1383, 1393, and 1401 were obtained from two Landsat 5 and 8 satellites. By running a band calculation function on the images of TM and OLI sensors, the values of the physical changes of the urban fabric during the investigated time steps in Sahand city were calculated and extracted. The results of this research indicated that the physical growth and development of the city of Sahand has started since 2013. This year, the area of the urban fabric has reached 282 hectares, which is a 28-fold increase compared to 2013. But in the next decade, i.e. 2013, the area of the city reached 570 hectares with a 100% growth compared to the previous decade, and finally, in the last decade, the area of the city reached 850 hectares with a growth rate of 50%. District 6 of Sahand city, which accounts for about 35% of the physical fabric of the city, has been one of the fastest growing areas of the city during the decades of 1393-1400. Considering that a significant correlation at the confidence level of 0.95 (P_value=0.05) was revealed between the population growth and the physical development of Sahand during the statistical period of 1380-1400 (R=0.91), therefore, the fitted regression model between the population growth And the growth of the urban fabric, by placing the proposed population density of this city after the implementation of Mehr housing policies (185 thousand people), it showed that the area of the physical fabric of this city will reach 1181 hectares in the next decade and will face a growth of 38%.
Mokhtar Karami,, Rahman Zandi,, Jalal Taheri,
Volume 20, Issue 56 (3-2020)
Abstract
In recent years with the development of cities coatings of the Earth's has changed surface. These changes have caused some urban areas to have a few degrees higher than the surrounding temperature. This phenomenon is known as thermal islands. Mashhad is one of the major metropolises in Iran with the problem of thermal islands. Various parameters affect the formation of thermal islands in this city that should be considered. In this study TM, ETM+ and OLI images were used to obtain surface temperature over the period 1987-2016. The study of temporal variations in surface temperature showed that in the studied period, thermal islands were transferred from outside the city to the city. The model for describing the temperature of the surface of the earth has changed and has diminished from the temperature of the city's moderate and cool temperatures, and in contrast, the amount of high temperatures (thermal islands) has increased significantly. The TOPSIS method was also used to obtain the thermal forming factors. 13 natural and human factors affecting the formation of thermal islands were identified. Each expert opinion factor was used to determine the degree of importance. According to experts, the distance from the sanctuary with a weight of %234 and traffic of %155 is the most important and the height with a weight of %022 is least important in the formation of thermal islands. The final results obtained from this model showed that the factors affecting the formation of thermal islands are well recognized and the temperature decreases with these factors.
