Spatiotemporal Analysis of Urban Growth Patterns to Provide Strategies for Sustainable Land Planning (Case Study: Bandar Abbas City)

Today, the optimal pattern of urban growth is one of the important topics of sustainable urban development. Therefore, the efforts of urban planners are to replace desirable urban patterns instead of sprawl, horizontal, unplanned, and unstable patterns. Therefore, to determine the spatiotemporal pattern of the growth of Bandar Abbas city in 36 years and formulate strategies for sustainable land planning, this research has examined the pattern of urban growth in three modes internal, external, and edge growth over time. To achieve the goal of the research, remote sensing techniques, geographic information system, landscape expansion index, Area weighted Mean expansion index, and the density of built areas in concentric zones around the organic core of the city have been used. In this regard, changes in the land cover through the classification of satellite images of four periods of 1987, 1999, 2010, and 2023 into five classes of built-up areas, barren lands, vegetation, coastal wetlands, and water zone using the maximum likelihood method. Determining the probability of conversion, the results of the research showed that in the 36-year period, the built-up lands had the largest area changes, and the barren lands had a decrease in area, and since 2009, the vegetation cover has faced a sharp decrease. Area. The results of the analysis of the landscape expansion index and the weighted average of the regional expansion index showed that in the first period (1987-1999) the city had an edge pattern and in the second period (1987-2010) it was inner and edge. The growth has increased and the pattern of the city has become denser and more compact and in the third period (2010-2023) the city has gone towards dispersion and instability. Finally, sustainable land planning tools have been presented.

The ever-increasing growth of the population of cities, under the influence of population growth and migration to cities, has caused unstable conditions in the pattern of urban development. The widespread and sprawl development around the city causes an increase in fuel consumption, air pollution, an increase in the cost of access to services, destruction of agricultural and garden lands around the city, and a decrease in the quality of landscapes. Therefore, urban planners consider urban growth patterns to solve urban problems and achieve sustainable urban development. In 1995, Forman divided urban growth patterns into three main classes: internal or endogenous development, edge or connected development, and external or detached development, which is an unstable form of urban development. Since the middle of the 20th century, urban sprawl refers to low-density development, scattered and far from urban centers, which causes the destruction of open lands and agricultural lands around the city. This development happens when the area of the city does not respond to the population added to the city and the expansion to the periphery causes the dispersion of urban functions outside the administrative boundaries. On the other hand, one of the most successful models of sustainable urban development in the world is endogenous development, whose main goal is balanced, balanced, and sustainable development. In endogenous development, instead of expanding the city to the periphery, the growth of the city takes place vertically and endogenously in the inner areas of the city, for this purpose, policies such as improving and renovating worn-out and old structures in the city and unused lands and land Empty spaces in the city are used for new developments. The case example of this research is the city of Bandar Abbas, which in recent years, under the influence of the rapid growth of population and area, has caused urban fragmentation and spatial instability of this city. For this purpose, policies such as improving and renovating worn-out and old structures in the city and unused lands and empty lands in the city are used for new developments. The case example of this research is the city of Bandar Abbas, which in recent years, under the influence of the rapid growth of population and area, has caused urban fragmentation and spatial instability of this city.

In this research, satellite images of 1987, 1999, 2010, and 2023 have been used to prepare maps of different land covers. These satellite images have been classified using ENVI software and training samples with a supervised classification method and maximum likelihood algorithm. Based on the purpose of this research, five classes of vegetation cover, bare land, built-up land, coastal wetland, and water zone have been considered. Also, the basis of the analysis of temporal spatial changes of three types of internal, sprawl, and edge expansion in this research is the land cover maps, for this purpose, the landscape expansion index, the weighted average expansion index of the area and the density of built areas in the area Concentric circles around the organic core of the city have been used.

The results obtained from the analysis of land cover changes indicate the upward trend of built-up lands from 1987 to 2023 so that in the 36-year period, built-up lands have increased by 3185.758 hectares. In contrast, barren lands have had a significant downward trend due to their conversion into built-up lands. These changes in recent years, in addition to the destruction of vegetation, and the destruction of natural landscapes, have caused the loss of urban cohesion and integration, and urban fragmentation and instability. The results of the analysis of the landscape expansion index and the weighted average expansion index of the region and the density of three types of internal, external, and edge growth around the organic core of the city, as well as edge and expansion and continuous growth on the outskirts of the city in line with the communication axes towards the edge The city in the period of 1987-1999 and 1999-2010 shows that in the period of 1999-2010, the intensity of intensive internal and edge growth increases. In the period of 2010-2023, the lands built separately and individually will grow significantly. Therefore, they create a bad and unbalanced urban growth. The strategies in five axes include 1) the use of barren lands within the city, 2) the redevelopment of unsuitable and abandoned lands within the city, 3) the redevelopment of old and dilapidated built areas within the city, 4) the use of higher density of buildings instead of development Low density is provided to the periphery of the city and 5) the use of the green belt.

Spatial and temporal planning of sustainable urban growth patterns requires analysis of land cover changes, formulation of strategies, and planning measures to modify and improve the state of urban growth patterns based on the proposed principles and suggested strategies of this research. The methods and strategies used in this article can be a guide for urban planners in guiding and controlling the physical changes of cities with the aim of improving the structure and performance of cities and as a result, improving the quality of life of citizens.