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Abstract

Urban form can be affected by diverse factors in different times. Socio- economic, political and physical factors are among the main contributors. So, one of the most important challenges of urban planners is measuring and identifying urban development pattern in order to direct and strengthen it to sustainable pattern and right direction. The case study of the present paper is the city of Yazd, a middle-sized city in the center of Iran, and the studied years are 1975, 1987, 2000 and 2010. To achieve the main objective of the paper, measuring Yazd growth and expansion by spatial metrics, it has used remote sensing data and satellite imageries and ArcGIS software. The conclusion revealed that in four periods of study, complexity or irregularity of the urban patch shapes has increased, centrality or average distance of the dispersed parts to the city center has decreased, compactness or the number and area of patches their distance from each other has decreased, porosity or ratio of open space has increased and finally population density of city has decreased in a large amount. Therefore, all perimeters show that the temporal - spatial form of Yazd has moved from compact to sprawl. Due to many undesired impacts of urban sprawl, urban planners and authorities are required to use adherent techniques and policies to control urban sprawl and to direct it toward more sustainable directions.

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Industrial revolution and its resulting changes have led to urban horizontal growing. Environmental pollution, more energy consumption, development without planning, Increased spending on infrastructure, particularly in the area of urban construction are the consequences of the urban horizontal growing. To remedy the crisis, efforts have been made to recognize patterns of urban development and the realization of sustainable urban form. Meanwhile, the compact city strategy was presented to solve the proposed problems. Compact city is an urban strategy to tackle the problem of sporadic and uncontrolled physical growth of cities. This study aimed to identify the obstacles to the realization of compact city strategy in the central part of Sari. The research method is qualitative on the basis of a theoretical approach. Data was collected in two ways of documentation and semi-structured interviews. The sample included people involved in urban development projects. Purposeful sampling was done using the snowball technique and finally 10 specialists in the research area were selected as the study sample. Results suggest that the presence of monuments, low interest of investors for construction, and inefficient transport system were among the obstacles of the realization of compact city strategy in the research area