Introduction
Urbanization is one of the consequences of the industrial revolution. One of the results of which is land use changes and uneven growth of urban areas, this is one of the main challenges of urban management in the 21st century (Esadi et al., 1400: 143). Therefore, new urbanization, and its growth policies in peri-urban spaces, in the form of horizontal urbanization and urban sprawl, have opened new borders and horizons in the concept of city development compared to its surrounding spaces. Therefore, the expansion of urban spaces and access to villages and around the city was called erosion or "urban creep". In such a way that life in the surrounding areas and peri-urban spaces as an existing reality should be compatible with the principles of urban planning (Sieverts, 2003: 13). On the other hand, land use changes along with the rapid growth of urbanization caused major changes in other uses and spaces around the city (Azri et al., 1400: 123). Therefore, considering the importance of the research problem, it is necessary to investigate the effects of population increase and its effect on land use changes in the city under study.
What distinguishes this research from previous studies is the use of remote sensing technology and the investigation of the effects of urban growth on land use changes. Therefore, the research questions are: According to the satellite images, what is the land use change between the years (1986 to 2020) in the city of Torbat Heydarieh? How much did the increase in population and the urban leap with regard to the peri-urban spaces between the years (2020 to 1986) affect the changes in the city's lands? What will be the amount of land use changes due to the development of peri-urban spaces in Torbat Heydarieh until the horizon of 2026?
 
Methodology
This research has been carried out with a practical purpose and a descriptive-analytical nature, using the library method and taking satellite images from the USGS site using the OLI Landsat 8 sensor and the TM Landsat 5 sensor between the years 1986-2013-2020 in the city of Torbat Heydarieh. . To output the maps from the sensors (TM & OLI), first the city boundaries are cut with the Extract by mask command in the Arc Map software. Then, the relevant layers have been classified into 4 classes (residential areas, garden and forest areas, vegetation and grass, barren lands) within the limits of this city with the supervised classification method. NDVI index is used to calculate vegetation changes. In order to predict land use changes until the year (2026), TERRSET software has been used using the CA-MARKOV model.
 
Results and discussion
To calculate land uses and land changes between 1986-2013-2020 based on Landsat 8 and 5 satellite images, the amount of land use area in 4 classes (residential areas - garden and forest areas - vegetation and grass - barren lands) using It was extracted from the supervised classification in Arc Map software. Changes in land use in 1986, according to the population and the development of peri-urban areas, showed that this city had more garden lands and vegetation. In 2013, with the increase of population towards the north, the area of ​​the city has increased by (21.725,150) square kilometers, compared to 1986. Therefore, the area of ​​the city in 2020 has increased by (25.765259) square kilometers compared to previous years. As a result, with the increase in the area of ​​the city and the development of peri-urban spaces, it has caused a decrease in vegetation and garden lands. NDVI index and vegetation changes in 1986-2013-2020 showed that in 2020, vegetation cover decreased with the increase of man-made areas. The transformation matrix of land uses showed that with the increase of changes in (1986-2020), vegetation and gardens have decreased, but residential areas have increased. The highest percentage of the area of ​​land use conversion probability in 1986-2013 is related to barren lands and the lowest area is related to garden lands. The highest area of ​​land use conversion probability in 1986-2020 was related to barren lands and the lowest area was related to residential areas. According to the prediction of land changes in TERRSET software in the years 1986 to 2020 with the Markov model predicting changes until the horizon of 2026, the area of ​​residential uses is always increasing. This has caused the reduction of vegetation and garden lands.
 
Conclusion
This research was conducted with the aim of evaluating the development of peri-urban spaces and predicting land use changes based on the CA-MARKOV model in the city of Torbat Heydarieh. The results of the prediction of land use changes until 2026 (1405) showed that residential areas with an area of ​​(25,170,300) square meters have had the most changes compared to garden and vegetation areas. Therefore, the results of this research are consistent with the results of Ismailpour et al. (2017) in Arak city, and Obayat et al. (2019) in Ahvaz city. Therefore, with the increase in population, it is predicted until the time horizon of 1405 With the increase in population and the development of peri-urban spaces, in the not too distant future we will witness the destruction of forest lands, gardens, vegetation and agricultural lands in this city and the transformation of these lands into residential and man-made areas. Therefore, the innovative aspect of the research is in this, using remote sensing technology and taking satellite images and comparing their data in three different time periods, the horizontal and vertical growth of the city should be evaluated according to the increase in population and urban growth. In the sense that the city should not only increase horizontally, but with the increase of high-rise buildings and apartment buildings, the amount of changes caused by them should be checked. Therefore, it is suggested to develop the city towards its east and south in order to prevent the destruction of vegetation and garden lands. 
 
Funding
According to the author, this article has no financial support.
 
Authors’ Contribution
Authors contributed equally to the conceptualization and writing of the article. All of the authors approved thecontent of the manuscript and agreed on all aspects of the work declaration of competing interest none.
 
Conflict of Interest
Authors declared no conflict of interest.
 
Acknowledgments
The authors are sincerely grateful to the participants who took part in the study.