عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Fast and uncontrollable growth of urbanization causes loss of agricultural lands and orchards; it leads to a decrease in green areas and open spaces and causes heavy traffic and environmental pollution. Therefore, an essential step in urban planning, management and evaluation of its effects is to simulate the physical development of the city. In order to keep ecosystems functioning well, it is necessary for environmental researchers, managers, and decision makers to understand the spatial dynamics of an ecosystem. Importantly, remotely sensed imagery provides an efficient means of obtaining information on temporal trends and spatial distribution of urban areas needed for understanding, modeling, and projecting land change. The aim of this study is to understand the parameters of physical development at Bonab city with regard to sustainable spatial development of urban issues from ecological and environmental viewpoint in the next two decades. Change detection is an important process for monitoring and managing natural resources and urban development because it provides quantitative analysis of spatial distribution in the area of interest. Detection of changes in land use/ land cover involves use of at least two period data sets. Using Landsat 5 multi temporal satellite images and object oriented techniques, application changes of the lands in 1984-2011 period was evaluated with emphasis on Sprawl expansion of Bonab urban area and its scattered peripheral villages located in the study area. The term Sprawl is used in various ways to mean the gluttonous use of land, uninterrupted monotonous development, leapfrog discontinuous development and inefficient use of land. Urban sprawls are characterized by premature or poorly planned conversion of rural land to other uses, the creation of areas of urban development or uses which are not functionally related to adjacent land uses, the creation of areas of urban development or uses which fail to maximize the use of existing public facilities and the use of areas within which public services are provided. For calculating this parameter Holdern index was used. Results show that 41 percent of urban growth of Bonab city has risen from sprawl growth. Based on the results, urban area of Bonab and its six peripheral villages which was 608.4 hectares in 1984 reached 1716.8 ha in 2011. 1065.51 hectares of the aforementioned lands was developed on garden and agricultural lands which demand management of future development based on the principles of sustainable development. Therefore, effective factors of physical development in the urban area of Bonab city was classified under 14 layers and by using the logistic regression method, the possibility of urban development map was prepared. After predicting the future pattern of urban development in Bonab city, the protection of gardens and green spaces strategy in the urban development process was implemented using the hexagonal layout of possibility for urban development map, giving the necessary space for development, and extraction of a natural green belt with an area of 21.83 km. Furthermore, a ban in urban development in the surroundings of the proposed green belt was applied, maintaining the ecological reserves of Bonab city by reducing agricultural and garden lands, decreasing degradation and controlling sprawl expansion and separation of towns and villages.