عنوان مقاله [English]
The rapid development of urbanization is one of the challenges for urban planners in the 21st century. Rapid urbanization in Iran, the influx of migrants to the cities and the lack of an effective program for settlement, due to informal settlements and marginal communities of cities and ultimately spread around the city, and agricultural land and Gardens have been destroyed Such that areas of cities by increasing migrants are experiencing extreme physical development.
In view of the issue of marginalization due to land degradation around the city, the formation of unsustainable urban network, rising urban crime, increased urban poverty and expanding discordant town, monitoring and management of growth and physical development of the city is essential and researchers have led to developments outside the program to control, monitor and forecast models.
Urban modelling in the cellular space, first by definition with that of the cellular geography tobler provided Urban studies has been compiled Cellular automata and is a perfect tool for modeling is the spatial dynamics Despite the benefits of Cellular automata model, this model also has it's limitations To create a true urban dynamics, simulation and not powerful enough Therefore, to fix the limits of this model usually combine it with used Markov chain model.
In this research, the Markov chain model and automated cells to simulate land use change process is used to evaluate the physical expansion of the city of Urmia between 1984 -2016 and to predict land use changes to year 1410.
To run the model, Satellite images of Landsat 5 and 7 and 8 in the years 1984, 1992, 2002, 2012, 2016of Urmia was prepared and then use ENVI software, IDRISI and Arc Gis, then land use changes were calculated and finally the Markov chain model and automated cells were run.
3-Results and discussion
Urmia city due to very favorable natural substrate (highly desirable areas of agriculture and water resources) and the development of communication network and immigration in recent years has been rapid population growth. The rapid growth of the population of the unorganize
Settlement and causes marginalization and ultimately caused the incorporation of surrounding land to the city, the settlements have been cooperative. Overview of the research carried out in conjunction with the physical growth of the city of Urmia which shows the capabilities of satellite images and models existing in connection with this type of data for the evaluation of physical growth of the city for less.
In this research with the use of the information contained in the images shown.That formed around the margins of the city in different time periods is one of the main factors of physical growth of tissue in the past decade. This form of growth and the expansion of the city caused the destruction of agricultural land and orchards of the region in particular. The amount of urban land use made of 2016.55 hektar in 1984to 6318.8 in the year 2016. And of 23.21 percent share of urban lands made to 702.72% is reached. In other words the range the city during this period has grown to 5 times. The amount of land needed for the growth of gardens inside the city and the land around the town providing a wasteland.
So that the area of garden and agricultural land around the city of 29.59 percent to 7.24 percent in year 1984 in the year 2016. Also during the period of nearly 32 years, mordmtalah half of Bayer's lands around the city about building maker is located. And 4101.19 Hectare (47.2 per cent) to 1741.35 Hectare (20.04%) decreased. In connection with the expansion of the city of Urmia when looked at ways 1984 up 2016 say: grow and expand in all directions. But the main directions of the city spread in the South and South West and South East of the city. And given that the southern part of the city in the most amount of agricultural lands and gardens. This amount has been changed to urban use. Also in the South-Eastern part is also the largest land use Bayer for the city. According to the map of predicted changes to urban lands made 2030 will increase. But the important point is that the total area of agricultural lands and orchards due to being the period before very underutilized. Decreased slightly, and that means we have a lot of ER Urmia City Gardens and agricultural land destroyed. It also reviews how the expansion of the city at this time indicated growth looked the initial nucleus of the marginalization and the rural settlements around the city. Continue with the process of the development of the city expanded and finally to the main body of the city have been connected. The simulation results also show that until year 2030, Urban built lands will increased to 7523.01 (86.58 percent) range of master plan. The area of gardens and agricultural lands reduced to 619.60 hectares and arid lands to 546.33 hectares will be reduced.
According to the tips listed in the city of Urmia, satellite imagery, maps and the results offered the following suggestions:
1. Due to the growth of the city and making indiscriminate opposition to the species of mushrooms and marginalization of the most recent period, it is necessary to monitor the municipality more accurate and more serious.
2. The physical development of the city update monitoring using satellite images with better separation for classification of land cover maps in the next research.
3. Due to being a dynamic process of land-use changes over time, it is recommended. In the meantime, the next research the use of dynamic models of physical and economic factors such as CA_Markov, social, and political factors, affecting the user changes, as well as comments to be considered.