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Volume 37, Issue 4 (2022)
GeoRes 2022, 37(4): 517-527 |
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Received: 2022/09/7 | Accepted: 2022/11/11 | Published: 2022/11/1
Received: 2022/09/7 | Accepted: 2022/11/11 | Published: 2022/11/1
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Akbari A, Eskandari Sani M, Esmaeilnezhad M. Effective Indicators on the Realization of Land Use Pattern and Future Expansion of Zahedan Urban Areas in its Comprehensive Development Plan. GeoRes 2022; 37 (4) :517-527
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1- Department of Geography and Urban Planning, Islamic Azad University, Zahedan, Iran
2- Department of Geography and Urban Planning, Birjand University, Birjand, Iran
2- Department of Geography and Urban Planning, Birjand University, Birjand, Iran
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Introduction
The trend toward urbanization is rapidly expanding worldwide due to population growth (Cohen, 2006). According to the United Nations report from 2007, more than half of the world’s population lives in cities, and it is predicted that the global urban population will reach 60% by 2030. Rapid population growth, urbanization, and their associated consequences in cities are undeniable phenomena, as cities, in accordance with their new roles and positions, impose new forms of social life on themselves and their surrounding spaces, affecting climate, agricultural production, public health, and social justice (Sfandeh et al., 2021). As cities grow in size and population, attention to the coordination among their physical, social, and environmental aspects becomes critical, and urban sustainability depends on the alignment of these factors. One serious issue contributing to the failure of previous master plans has been the lack of implementation of proposed land uses and urban boundaries in general, and the failure to implement public service land uses in particular, which can significantly affect other planning projections.
The model of urban development plans in Iran has been prevalent for nearly half a century, influenced by Western planning models. The implementation of these plans, based on the conditions and needs of the time, has produced a mix of positive and negative outcomes, which today require comprehensive evaluation and meticulous revision to improve and advance urban planning. The main achievements of the comprehensive planning model and detailed master plans in Iran can be summarized as establishing a legal supervision system for urban development and construction processes and promoting new urban planning knowledge and methods to respond to new urban needs, including mass housing production, expansion of transportation systems, and development of new urban spaces. From the outset of preparing and implementing the first comprehensive and detailed plans in Iran, some of their problems and shortcomings became more or less apparent to practitioners, and the first criticisms and reform suggestions emerged in the mid-1970s and have continued to the present. Initially, these criticisms mostly concerned the legal procedures for preparing, approving, and implementing plans, but later expanded to include the content of the plans and their theoretical and methodological foundations (Pirzadeh, 2008). One of the clearest problems facing urban planning in Iran is the failure to implement comprehensive plans and achieve the objectives set out in them. Comprehensive plans, prepared at considerable expense for Iranian cities, have often failed in practice, sometimes not only failing to improve urban planning processes and cities, but also contributing to physical, economic, and social disorder, as well as administrative corruption.
In the study “A Review of Urban Planning Patterns in Iran” (1990), the deficiencies and challenges of urban development plans were summarized in three areas: the content of the plans, the methods of review and approval, and implementation issues. Qomami, in the article “A Brief Review and Critique of Urban Master Plans,” identifies three main sources of failure in urban comprehensive plans: Misalignment of the plan with natural conditions, the dynamic nature of cities and society, and deficiencies in the urban management system (Qomami, 1992). In a more comprehensive study titled “Evaluation of Urban Master Plans in Iran” (1993), the implementation of seven urban master plans was assessed, and it was concluded that these plans failed to achieve their intended objectives (Nourian & Vahidi Borji, 2015). Vahidi Borji and colleagues have identified three major factors contributing to the failure of land use development plans in Iran: Unstructured and improper decision-making by city managers, negative financial balances of municipalities with revenue generation through violations of the plan’s proposals, and unrealistic planning and provision of illogical suggestions (Vahidi Borji et al., 2017). Athari, in the article “Crisis of Thought in Iranian Urban Planning,” attributes the failure of urban master plans to weak theoretical foundations and the methods derived from them (Athari, 1994). Behzadfar, in the book Urban Plans and Programs, examines the methodology of conducting comprehensive and detailed plans, citing four studies in this area, and concluded that these plans were ineffective and unachievable (Behzadfar, 2004). He identifies realism and flexibility in goal-setting and evaluating implementation capacities as critical factors affecting the feasibility of these plans (Rahnamaee & Shah-Hosseini, 2007).
According to Behzadfar, because there was no targeted program for preparing comprehensive plans and the government, due to political considerations, encouraged urbanization at the time, the proposed guidelines and requirements of comprehensive plans were largely ignored in practice. Studies of urban master plans indicate that in no city did existing boundaries match the planned boundaries, nor were urban plans integrated with national plans, macro policies, or the economic and political conditions of the time. Additionally, population, industrial, service, and agricultural projections in these plans were associated with a high margin of error. In evaluating master plans, it can be said that besides deficiencies related to the objectives and intentions of the plans, content-related problems were also significant. Alongside managerial issues, deficiencies related to human resources and executive organizations, environmental and contextual challenges, lack of coordination among implementing agencies, and financial constraints are important. Moreover, legal and regulatory shortcomings are another group of factors affecting the execution and effectiveness of comprehensive plans. Taken together, these issues demonstrate the abstract nature of comprehensive plans and how they have added to the challenges of urban governance in Iranian cities, particularly in Zahedan, a growing and developing city.
Zahedan, the largest city in southeastern Iran, has experienced one of the most irregular patterns of physical urban growth over the past three decades (Ebrahimzadeh et al., 2004). According to experts at the Zahedan Foreign Nationals and Immigrants Office, the city’s population has now reached nearly one million, with an average annual growth rate of 6.6%, and according to the 2016 Iran Statistics Center, a large portion of its urban population resides in informal settlements. In 2005, the legal area of Zahedan covered approximately 6,468.5 hectares, much of which was allocated to educational, medical, sports, and administrative land uses, while some portions consisted of vacant lands, gardens, and agricultural areas within the city fabric (Jamshidzehi Shahbakhsh & Ghanbari, 2020). In addition to the legal area, around 396.6 hectares outside the legal boundaries were composed of adjacent villages and facilities such as hospitals and religious centers. Therefore, the total study area is currently 6,865.2 hectares, of which 94.2% lies within legal boundaries and 5.7% outside. Population-driven urban sprawl of approximately 40% indicates that 200 hectares of previously unincorporated land have been added to the legal area and now belong to the urban periphery, with the trend expected to continue due to future growth. Given the city’s extensive area, the influx of settlers, and the lack of enforceable laws, the geometric form of Zahedan’s urban boundary is constantly subjected to public and private encroachments, affecting urban guidance and development and challenging the implementation of many future urban development programs.
Since previous plans and programs have been introduced to address these issues but have not been effective, this study seeks to identify factors affecting the feasibility of land use implementation and to assess the historical growth of the city. This enables the determination of a smart direction for urban expansion and the identification of intervening factors in these changes. Planning to improve land use implementation patterns can largely guide the city’s trajectory toward a sustainable urban future.
Methodology
This applied research, based on a descriptive–analytical approach, was conducted in 2021 within the urban area of Zahedan, located in Sistan and Baluchestan Province.
At the outset, the spatial growth of the urban area during the period 1991–2021 was determined using four sets of satellite imagery. The SLEUTH model was then employed to identify patterns of urban growth and to distinguish between desirable and undesirable development zones. Additionally, content analysis was used to identify indicators influencing the realization of the land-use pattern and the factors contributing to urban expansion in Zahedan.
The SLEUTH model is designed to simulate urban growth processes using cellular automata. It extracts urban growth patterns based on four types of land-use changes: spontaneous growth, new spreading center growth, edge growth, and road-influenced growth. These four types of growth operate during each simulation cycle and are controlled through the interaction of five coefficients: diffusion, breed, spread, road gravity, and slope resistance (Clarke & Gaydos, 1998).
The essential input layers required for SLEUTH include slope, land use, exclusion layers, urban layers, transportation networks, and elevation data. These input layers were prepared in the GIS environment using remote sensing data and a Digital Elevation Model (DEM). Since GIS processing requires all spatial data to be geometrically consistent and to follow a unified coordinate system, all datasets in this study were geometrically corrected using ground control points with an acceptable root mean square error (RMS<1). Land-use maps were classified using the maximum likelihood method.
To determine the importance of indicators affecting desirable urban growth, the Analytic Network Process (ANP) was applied. The Analytic Hierarchy Process (AHP) was then used to evaluate balanced scores and assign weights to the layers influencing growth. These weighted layers were overlaid to produce the final suitability map for land development in Zahedan, which was subsequently incorporated into the SLEUTH model. In this stage, 18 experts in urban planning and management were selected using purposive sampling, and a total of 15 completed questionnaires were used for analysis.
In GIS, two major approaches exist for overlaying spatial layers: the weighted linear combination and Boolean methods. In the weighted linear combination approach, compensatory behavior is allowed; that is, a low score in one criterion can be offset by a high score in another. In this method, each layer is multiplied by its corresponding AHP-derived weight, and the layers are combined to produce the final suitability surface.
Next, parameters and indicators related to the realization of the land-use pattern in Zahedan were identified based on expert judgment. Based on the experts’ evaluations, a network model for assessing the degree of land-use realization in urban development plans was constructed using the Super Decisions software. In this network, the first cluster represents the study’s overall objective, the second cluster contains the evaluation criteria, and the third cluster includes the indicators associated with each of the twelve main criteria. The indicators within each dimension are interdependent, reflecting their internal relationships. Based on this structure, an initial supermatrix and corresponding submatrices were created. In ANP, the weight vector for factors can be computed directly by generating pairwise comparison matrices or by normalizing percentage variations of the factors (Zebardast, 2010).
After computing the importance coefficient for each indicator of urban development, the Balanced Scorecard (BSC) method was used to evaluate the realization of land-use patterns in the Zahedan master plan. The assessment scores derived from the master plan, along with the indicator weights obtained from ANP, were entered into the BSC software to calculate the overall and dimension-specific realization levels of the land-use model.
In the final stage, calibration of the input layers was performed to obtain the optimal values of the growth coefficients for the study area. The calibration of the SLEUTH model was carried out using the brute-force method. The set of coefficients derived from the calibration process represents the initial values and reflects how urban growth occurred in the past. SLEUTH uses these calibrated coefficients to predict future growth patterns across the entire study area.
Findings
The indicators identified in the study were finalized based on data availability, alignment with the objectives, and the specific conditions of the city of Zahedan, as well as comparisons with previous research. All factors influencing the optimal urban growth of Zahedan were incorporated into a linear–weighted overlay analysis within GIS. At this stage, each layer was multiplied by its corresponding AHP weight, and the final overlay was produced. Accordingly, the urban growth suitability map was generated based on the selected indicators.
The results demonstrated the spatial expansion of the urban area during the study period, along with the classification of suitable and unsuitable zones. Physical development constraints were identified in portions of the northern and eastern areas of Zahedan. The presence of obstacles such as transmission lines in the south and elevated terrain in the northern and eastern sectors were identified as major growth-limiting factors. The most suitable zones for future urban expansion were predominantly located in the northwestern, northeastern, southeastern, and southwestern parts of the city. In the northern areas, the spatial pattern of actual growth corresponded with the suitability zones, whereas in parts of the northwestern and western areas, the observed growth pattern did not align with the suitability zones based on the identified factors.
Evaluation of the Realization of Land-Use Proposals Using the BSC Method
After calculating the importance weight of each parameter and indicator through network analysis, the Balanced Scorecard (BSC) framework was used to evaluate the feasibility of implementing land-use proposals in the comprehensive plan of Zahedan. Following the computation of the primary supermatrix elements using the Super Decisions software, the indicator weights were extracted from the goal column of the limit supermatrix.
Among the twelve main criteria considered in this study, the criterion of an efficient transportation network had the highest importance weight and therefore ranked first in determining the feasibility of land-use patterns. This was followed by urban vitality and spatial integration as the second priority, land and building value as the third priority, and environmental risks and pollution as the fourth priority. Among the five main dimensions, the physical dimension achieved the highest level of feasibility, while the socio-cultural dimension ranked lowest. The environmental, economic, and managerial dimensions followed in subsequent order. Overall, the realization of the proposed land-use pattern was evaluated as moderate to low.
Calibration Results and Urban Growth Simulation Using the SLEUTH-3r Model
Model calibration was conducted for the period 1991–2021. Based on the recommendations of Jantz et al. (2014), three calibration metrics of Cluster Fraction Difference, Edge Difference, and Area Difference were used to determine the model coefficients.
The calibration results indicated that the diffusion coefficient had the highest value, reflecting predominantly organic urban growth. In other words, from the base year to the end of the calibration period, urban development w:as char:acterized by edge growth and organic expansion, typical of intrinsic urban development patterns where undeveloped patches within or at the edges of the city gradually transition into urban land uses.
The road gravity coefficient ranked second, highlighting the strong influence of transportation infrastructure on urban development and new construction activities. The slope resistance coefficient ranked third; however, given its relatively low value, slope had minimal influence on urban growth in Zahedan during the calibration period. The breed coefficient showed minimal influence on growth, and the spread coefficient exhibited almost no impact, indicating negligible spontaneous growth. Based on the model coefficients, the patterns most aligned with the observed growth were organic expansion and road-influenced growth.
The cumulative urbanization potential values also revealed that cells with an urbanization probability of 90% or higher represented the most likely areas for future development. These cells were therefore designated as urbanized in the final spatial simulation.
Urban Growth Trends and Spatial Expansion Projections for 1450 (2071–72)
The results showed that urban growth in Zahedan will initially occur internally, meaning that undeveloped land and reserved urban areas within the approved boundary will be developed first. After these areas were filled, outward edge expansion occurs. Given that most informal settlements have historically expanded in the northeastern and eastern sectors, including beyond the city boundary, the emergence of new growth zones in the west and southwest indicates high suitability for future development in these regions. This also implies that developable land in the informal settlement regions will gradually be depleted.
Unlike the scattered and spontaneous growth pattern observed between 1991 and 2021 that is characterized by dispersed development in the western areas influenced by large-scale township policies, the future growth trend projected to 1450 will not be characterized by scattered or spontaneous expansion. Instead, growth will follow an edge-expansion pattern, largely through the incorporation of the Ghadir and Jihad townships into the northern and southern districts of the city. Since major growth constraints, such as the airport, flood channels, and steep topography are primarily located in the eastern areas, the shift of growth toward the west and south reflects the effectiveness of urban development plans in directing future expansion.
Urban growth must remain proportionate to population growth to adequately support the increasing number of residents. The city’s area more than doubled from 1991 to 2021, increasing from 3,684 hectares to 7,297 hectares. According to the SLEUTH model projections, the city’s area will reach 10,819 hectares by 1450, representing approximately a 30% increase relative to 2021. The population, however, is expected to reach only 618,663 based on average historical growth rates. This discrepancy will result in a significant decrease in population density from 89 persons per hectare in 2021 to 57 persons per hectare in 1450 indicating that physical growth is outpacing population growth, reflecting excessive horizontal expansion.
Population Capacity Assessment for the Urban Expansion of Zahedan by 1450
Estimating the population capacity of newly developed areas is essential for physical and service planning. In this study, population capacity was calculated based on the recommended density of 113 persons per hectare from the 2011 comprehensive plan.
The added urban area by 1450 is estimated at 3,521 hectares, allowing for an additional population capacity of approximately 397,968 persons. Therefore, the total population capacity of Zahedan by 1450 is projected to reach approximately 985,698 persons. This figure exceeds the expected population based on historical growth rates by nearly 300,000 persons.
This indicated that the amount of newly added urban land will more than accommodate future population growth, and no additional expansion of urban boundaries will be necessary. The projected density of 113 persons per hectare is considerably higher than the expected population density, suggesting that such a standard would lead to excessive horizontal expansion and unnecessary spatial dispersion of the city.
Discussion
In the present study, the extent of land-use pattern realization, its relationship with urban spatial expansion, and the future growth trajectory of the city were examined. The findings indicated that the physical (49.28%), environmental (46.30%), economic (43.40%), and managerial (38.10%) dimensions experienced the highest levels of development in Zahedan’s land-use pattern, whereas the socio-cultural dimension (32.26%) exhibited the lowest level of development. The socio-cultural dimension was among the most influential factors in shaping urban physical development, particularly in the formation of informal settlements. This dimension was itself affected by other parameters such as economic conditions. Neglecting employment opportunities, increasing rural-to-urban migration due to the absence of suitable rural employment, poverty, and unequal income distribution all contributed to the expansion of urban areas through the proliferation of informal settlements, an issue evident in Zahedan as well. Therefore, greater attention to socio-cultural dimensions is required to guide urban land-use patterns more effectively than other dimensions.
According to the results, the realization rate of the land-use plan in the Zahedan Master Plan was 41.86%, which was nearly average. Numerous studies have indicated that land-use realization rarely aligns with urban development plans or falls below anticipated levels. Similar findings have been reported by Ebrahimi Boozani and Zamani Joharestani (2021) in Malayer, and by Shokohi Bidhendi and Khaliji (2004), who have reviewed the reasons for the low realization of the Baneh Master Plan, concluding that many components of the plan had achieved less than 60% realization. Taghvaee and Mousavi (2007) have assessed the feasibility of the Mahyariz Development Plan, finding that physical and spatial development had exceeded 100%, indicating uncontrolled urban growth such that the city would have sufficient land capacity to accommodate population growth for the next 26 years. Overall, previous research on land-use patterns and the expansion of urban boundaries in development plans including studies by Khakpour et al. (2007), Movahed & Samadi (2011), Hoseyn Zadeh Dlir et al. (2010), Lotfi et al. (2004), and Zarabi et al. (2010) highlights inconsistencies and inefficiencies between actual land use and the intended development framework.
Land-use patterns, as one of the most sensitive subjects in urban planning, are not solely physical issues; rather, they encompass all social, economic, environmental, and managerial processes occurring within the city. It is therefore essential that comprehensive development plans, particularly master plans intended to guide holistic urban development, give adequate attention to these dimensions, as examined in this study. The enhancement of land-use patterns for the implementation of urban master plans requires specific principles that facilitate planning. These principles function as catalysts that help improve land-use patterns and enable the achievement of planning objectives.
The findings of this research highlighted the inherent limitations of all growth-modeling approaches, including the SLEUTH model, particularly its weak capacity to incorporate non-spatial and subjective factors such as cultural parameters and other elements that cannot be spatially or quantitatively represented. Consequently, the model outputs in this study could not fully reflect all determinants of urban growth in the simulation of Zahedan’s future expansion or in assessing land-use realization in development plans. Nonetheless, this research sought to mitigate these limitations by considering multiple influential factors in Zahedan’s growth through simulation and expert-based evaluation.
Modeling projections for 1450 (2071–72) indicated that, despite the urban growth observed between 1991 and 2021, the rate of physical expansion will decelerate in the forecast horizon. One major reason was the incorporation of Zahedan’s unique constraints and determinants of urban growth. Most land-requirement estimations employed simplistic calculations based solely on minimum per-capita land standards; however, this study considered critical contextual factors influencing Zahedan’s growth, supported by software-based analysis and expert judgement, to provide a more realistic representation of future land-use patterns.
As anticipated, the western areas of the city exhibited greater suitability and capacity for development, a result also supported by the model’s 1450 projections. Hence, the growth pattern of Zahedan reflects the influence of the criteria used in this study. Given the city’s arid desert climate, the projected expansion was not expected to harm the natural environment, as most surrounding barren lands will be converted into urban uses. However, in some areas, particularly the eastern zones, the projected pattern may lead to urban expansion into unsuitable areas with steep slopes or flood-prone channels. This would complicate the provision of urban services and the realization of proposed land-use patterns in future development plans.
Zahedan had a high proportion of informal and marginal settlements, predominantly in the eastern periphery and outside the official city limits. In addition, demographic statistics were sometimes inconsistent, making it difficult for official analyses to accurately reflect real-world growth patterns. In this study, efforts were made to ensure that land-use change detection and future growth modeling extended beyond administrative boundaries, incorporating larger settlement clusters. Modeling resulted to 1450 and population-absorption scenario calculations demonstrate a significant discrepancy between urban physical growth and population growth, primarily due to the absence of reliable demographic data and the excessive expansion of informal areas.
Based on the findings, urban sprawl cannot be properly understood without considering spatial patterns. While the methodology and model employed in this research differed from previous studies in Iran, they were consistent with international research conducted by Saxena & Jat (2019), Agyemang et al. (2022), and Li et al. (2018). Given the systemic and complex nature of urban development, driven by numerous intertwined factors it is recommended that future studies incorporate a wider range of parameters into modeling efforts, develop alternative environmental and socio-economic impact scenarios, and test multiple approaches to achieve more intelligent and accurate predictions of urban growth.
Conclusion
The weak performance of the social, economic, and managerial indicators in Zahedan has, to some extent, distanced the city from the objectives set out in its comprehensive physical development plan. Therefore, it is essential to identify the city’s needs and potentials in order to determine development capacities across different sectors. Overall, the findings indicate that the Zahedan Master Plan has achieved less than 50% of its intended goals. This shortfall can be attributed primarily to the lack of adequate attention to socio-cultural dimensions of urban development. Such issues, despite appropriate planning, can only be effectively addressed through the active participation of stakeholders and influential groups, ensuring greater realization and effectiveness of urban development plans.
Acknowledgments: No acknowledgments were reported by the authors.
Ethical Permissions: No ethical permissions were reported by the authors.
Competing Interests: The authors declare no conflicts of interest.
Authors’ Contributions: Akbari A (First Author), Introduction Writer/Main Researcher (50%); Eskandari Sani M (Second Author), Methodologist/Discussion Writer (30%); Esmaeilnezhad M (Third Author), Assistant Researcher/Statistical Analyst (20%)
Funding: This study was funded through the authors’ personal resources.
The trend toward urbanization is rapidly expanding worldwide due to population growth (Cohen, 2006). According to the United Nations report from 2007, more than half of the world’s population lives in cities, and it is predicted that the global urban population will reach 60% by 2030. Rapid population growth, urbanization, and their associated consequences in cities are undeniable phenomena, as cities, in accordance with their new roles and positions, impose new forms of social life on themselves and their surrounding spaces, affecting climate, agricultural production, public health, and social justice (Sfandeh et al., 2021). As cities grow in size and population, attention to the coordination among their physical, social, and environmental aspects becomes critical, and urban sustainability depends on the alignment of these factors. One serious issue contributing to the failure of previous master plans has been the lack of implementation of proposed land uses and urban boundaries in general, and the failure to implement public service land uses in particular, which can significantly affect other planning projections.
The model of urban development plans in Iran has been prevalent for nearly half a century, influenced by Western planning models. The implementation of these plans, based on the conditions and needs of the time, has produced a mix of positive and negative outcomes, which today require comprehensive evaluation and meticulous revision to improve and advance urban planning. The main achievements of the comprehensive planning model and detailed master plans in Iran can be summarized as establishing a legal supervision system for urban development and construction processes and promoting new urban planning knowledge and methods to respond to new urban needs, including mass housing production, expansion of transportation systems, and development of new urban spaces. From the outset of preparing and implementing the first comprehensive and detailed plans in Iran, some of their problems and shortcomings became more or less apparent to practitioners, and the first criticisms and reform suggestions emerged in the mid-1970s and have continued to the present. Initially, these criticisms mostly concerned the legal procedures for preparing, approving, and implementing plans, but later expanded to include the content of the plans and their theoretical and methodological foundations (Pirzadeh, 2008). One of the clearest problems facing urban planning in Iran is the failure to implement comprehensive plans and achieve the objectives set out in them. Comprehensive plans, prepared at considerable expense for Iranian cities, have often failed in practice, sometimes not only failing to improve urban planning processes and cities, but also contributing to physical, economic, and social disorder, as well as administrative corruption.
In the study “A Review of Urban Planning Patterns in Iran” (1990), the deficiencies and challenges of urban development plans were summarized in three areas: the content of the plans, the methods of review and approval, and implementation issues. Qomami, in the article “A Brief Review and Critique of Urban Master Plans,” identifies three main sources of failure in urban comprehensive plans: Misalignment of the plan with natural conditions, the dynamic nature of cities and society, and deficiencies in the urban management system (Qomami, 1992). In a more comprehensive study titled “Evaluation of Urban Master Plans in Iran” (1993), the implementation of seven urban master plans was assessed, and it was concluded that these plans failed to achieve their intended objectives (Nourian & Vahidi Borji, 2015). Vahidi Borji and colleagues have identified three major factors contributing to the failure of land use development plans in Iran: Unstructured and improper decision-making by city managers, negative financial balances of municipalities with revenue generation through violations of the plan’s proposals, and unrealistic planning and provision of illogical suggestions (Vahidi Borji et al., 2017). Athari, in the article “Crisis of Thought in Iranian Urban Planning,” attributes the failure of urban master plans to weak theoretical foundations and the methods derived from them (Athari, 1994). Behzadfar, in the book Urban Plans and Programs, examines the methodology of conducting comprehensive and detailed plans, citing four studies in this area, and concluded that these plans were ineffective and unachievable (Behzadfar, 2004). He identifies realism and flexibility in goal-setting and evaluating implementation capacities as critical factors affecting the feasibility of these plans (Rahnamaee & Shah-Hosseini, 2007).
According to Behzadfar, because there was no targeted program for preparing comprehensive plans and the government, due to political considerations, encouraged urbanization at the time, the proposed guidelines and requirements of comprehensive plans were largely ignored in practice. Studies of urban master plans indicate that in no city did existing boundaries match the planned boundaries, nor were urban plans integrated with national plans, macro policies, or the economic and political conditions of the time. Additionally, population, industrial, service, and agricultural projections in these plans were associated with a high margin of error. In evaluating master plans, it can be said that besides deficiencies related to the objectives and intentions of the plans, content-related problems were also significant. Alongside managerial issues, deficiencies related to human resources and executive organizations, environmental and contextual challenges, lack of coordination among implementing agencies, and financial constraints are important. Moreover, legal and regulatory shortcomings are another group of factors affecting the execution and effectiveness of comprehensive plans. Taken together, these issues demonstrate the abstract nature of comprehensive plans and how they have added to the challenges of urban governance in Iranian cities, particularly in Zahedan, a growing and developing city.
Zahedan, the largest city in southeastern Iran, has experienced one of the most irregular patterns of physical urban growth over the past three decades (Ebrahimzadeh et al., 2004). According to experts at the Zahedan Foreign Nationals and Immigrants Office, the city’s population has now reached nearly one million, with an average annual growth rate of 6.6%, and according to the 2016 Iran Statistics Center, a large portion of its urban population resides in informal settlements. In 2005, the legal area of Zahedan covered approximately 6,468.5 hectares, much of which was allocated to educational, medical, sports, and administrative land uses, while some portions consisted of vacant lands, gardens, and agricultural areas within the city fabric (Jamshidzehi Shahbakhsh & Ghanbari, 2020). In addition to the legal area, around 396.6 hectares outside the legal boundaries were composed of adjacent villages and facilities such as hospitals and religious centers. Therefore, the total study area is currently 6,865.2 hectares, of which 94.2% lies within legal boundaries and 5.7% outside. Population-driven urban sprawl of approximately 40% indicates that 200 hectares of previously unincorporated land have been added to the legal area and now belong to the urban periphery, with the trend expected to continue due to future growth. Given the city’s extensive area, the influx of settlers, and the lack of enforceable laws, the geometric form of Zahedan’s urban boundary is constantly subjected to public and private encroachments, affecting urban guidance and development and challenging the implementation of many future urban development programs.
Since previous plans and programs have been introduced to address these issues but have not been effective, this study seeks to identify factors affecting the feasibility of land use implementation and to assess the historical growth of the city. This enables the determination of a smart direction for urban expansion and the identification of intervening factors in these changes. Planning to improve land use implementation patterns can largely guide the city’s trajectory toward a sustainable urban future.
Methodology
This applied research, based on a descriptive–analytical approach, was conducted in 2021 within the urban area of Zahedan, located in Sistan and Baluchestan Province.
At the outset, the spatial growth of the urban area during the period 1991–2021 was determined using four sets of satellite imagery. The SLEUTH model was then employed to identify patterns of urban growth and to distinguish between desirable and undesirable development zones. Additionally, content analysis was used to identify indicators influencing the realization of the land-use pattern and the factors contributing to urban expansion in Zahedan.
The SLEUTH model is designed to simulate urban growth processes using cellular automata. It extracts urban growth patterns based on four types of land-use changes: spontaneous growth, new spreading center growth, edge growth, and road-influenced growth. These four types of growth operate during each simulation cycle and are controlled through the interaction of five coefficients: diffusion, breed, spread, road gravity, and slope resistance (Clarke & Gaydos, 1998).
The essential input layers required for SLEUTH include slope, land use, exclusion layers, urban layers, transportation networks, and elevation data. These input layers were prepared in the GIS environment using remote sensing data and a Digital Elevation Model (DEM). Since GIS processing requires all spatial data to be geometrically consistent and to follow a unified coordinate system, all datasets in this study were geometrically corrected using ground control points with an acceptable root mean square error (RMS<1). Land-use maps were classified using the maximum likelihood method.
To determine the importance of indicators affecting desirable urban growth, the Analytic Network Process (ANP) was applied. The Analytic Hierarchy Process (AHP) was then used to evaluate balanced scores and assign weights to the layers influencing growth. These weighted layers were overlaid to produce the final suitability map for land development in Zahedan, which was subsequently incorporated into the SLEUTH model. In this stage, 18 experts in urban planning and management were selected using purposive sampling, and a total of 15 completed questionnaires were used for analysis.
In GIS, two major approaches exist for overlaying spatial layers: the weighted linear combination and Boolean methods. In the weighted linear combination approach, compensatory behavior is allowed; that is, a low score in one criterion can be offset by a high score in another. In this method, each layer is multiplied by its corresponding AHP-derived weight, and the layers are combined to produce the final suitability surface.
Next, parameters and indicators related to the realization of the land-use pattern in Zahedan were identified based on expert judgment. Based on the experts’ evaluations, a network model for assessing the degree of land-use realization in urban development plans was constructed using the Super Decisions software. In this network, the first cluster represents the study’s overall objective, the second cluster contains the evaluation criteria, and the third cluster includes the indicators associated with each of the twelve main criteria. The indicators within each dimension are interdependent, reflecting their internal relationships. Based on this structure, an initial supermatrix and corresponding submatrices were created. In ANP, the weight vector for factors can be computed directly by generating pairwise comparison matrices or by normalizing percentage variations of the factors (Zebardast, 2010).
After computing the importance coefficient for each indicator of urban development, the Balanced Scorecard (BSC) method was used to evaluate the realization of land-use patterns in the Zahedan master plan. The assessment scores derived from the master plan, along with the indicator weights obtained from ANP, were entered into the BSC software to calculate the overall and dimension-specific realization levels of the land-use model.
In the final stage, calibration of the input layers was performed to obtain the optimal values of the growth coefficients for the study area. The calibration of the SLEUTH model was carried out using the brute-force method. The set of coefficients derived from the calibration process represents the initial values and reflects how urban growth occurred in the past. SLEUTH uses these calibrated coefficients to predict future growth patterns across the entire study area.
Findings
The indicators identified in the study were finalized based on data availability, alignment with the objectives, and the specific conditions of the city of Zahedan, as well as comparisons with previous research. All factors influencing the optimal urban growth of Zahedan were incorporated into a linear–weighted overlay analysis within GIS. At this stage, each layer was multiplied by its corresponding AHP weight, and the final overlay was produced. Accordingly, the urban growth suitability map was generated based on the selected indicators.
The results demonstrated the spatial expansion of the urban area during the study period, along with the classification of suitable and unsuitable zones. Physical development constraints were identified in portions of the northern and eastern areas of Zahedan. The presence of obstacles such as transmission lines in the south and elevated terrain in the northern and eastern sectors were identified as major growth-limiting factors. The most suitable zones for future urban expansion were predominantly located in the northwestern, northeastern, southeastern, and southwestern parts of the city. In the northern areas, the spatial pattern of actual growth corresponded with the suitability zones, whereas in parts of the northwestern and western areas, the observed growth pattern did not align with the suitability zones based on the identified factors.
Evaluation of the Realization of Land-Use Proposals Using the BSC Method
After calculating the importance weight of each parameter and indicator through network analysis, the Balanced Scorecard (BSC) framework was used to evaluate the feasibility of implementing land-use proposals in the comprehensive plan of Zahedan. Following the computation of the primary supermatrix elements using the Super Decisions software, the indicator weights were extracted from the goal column of the limit supermatrix.
Among the twelve main criteria considered in this study, the criterion of an efficient transportation network had the highest importance weight and therefore ranked first in determining the feasibility of land-use patterns. This was followed by urban vitality and spatial integration as the second priority, land and building value as the third priority, and environmental risks and pollution as the fourth priority. Among the five main dimensions, the physical dimension achieved the highest level of feasibility, while the socio-cultural dimension ranked lowest. The environmental, economic, and managerial dimensions followed in subsequent order. Overall, the realization of the proposed land-use pattern was evaluated as moderate to low.
Calibration Results and Urban Growth Simulation Using the SLEUTH-3r Model
Model calibration was conducted for the period 1991–2021. Based on the recommendations of Jantz et al. (2014), three calibration metrics of Cluster Fraction Difference, Edge Difference, and Area Difference were used to determine the model coefficients.
The calibration results indicated that the diffusion coefficient had the highest value, reflecting predominantly organic urban growth. In other words, from the base year to the end of the calibration period, urban development w:as char:acterized by edge growth and organic expansion, typical of intrinsic urban development patterns where undeveloped patches within or at the edges of the city gradually transition into urban land uses.
The road gravity coefficient ranked second, highlighting the strong influence of transportation infrastructure on urban development and new construction activities. The slope resistance coefficient ranked third; however, given its relatively low value, slope had minimal influence on urban growth in Zahedan during the calibration period. The breed coefficient showed minimal influence on growth, and the spread coefficient exhibited almost no impact, indicating negligible spontaneous growth. Based on the model coefficients, the patterns most aligned with the observed growth were organic expansion and road-influenced growth.
The cumulative urbanization potential values also revealed that cells with an urbanization probability of 90% or higher represented the most likely areas for future development. These cells were therefore designated as urbanized in the final spatial simulation.
Urban Growth Trends and Spatial Expansion Projections for 1450 (2071–72)
The results showed that urban growth in Zahedan will initially occur internally, meaning that undeveloped land and reserved urban areas within the approved boundary will be developed first. After these areas were filled, outward edge expansion occurs. Given that most informal settlements have historically expanded in the northeastern and eastern sectors, including beyond the city boundary, the emergence of new growth zones in the west and southwest indicates high suitability for future development in these regions. This also implies that developable land in the informal settlement regions will gradually be depleted.
Unlike the scattered and spontaneous growth pattern observed between 1991 and 2021 that is characterized by dispersed development in the western areas influenced by large-scale township policies, the future growth trend projected to 1450 will not be characterized by scattered or spontaneous expansion. Instead, growth will follow an edge-expansion pattern, largely through the incorporation of the Ghadir and Jihad townships into the northern and southern districts of the city. Since major growth constraints, such as the airport, flood channels, and steep topography are primarily located in the eastern areas, the shift of growth toward the west and south reflects the effectiveness of urban development plans in directing future expansion.
Urban growth must remain proportionate to population growth to adequately support the increasing number of residents. The city’s area more than doubled from 1991 to 2021, increasing from 3,684 hectares to 7,297 hectares. According to the SLEUTH model projections, the city’s area will reach 10,819 hectares by 1450, representing approximately a 30% increase relative to 2021. The population, however, is expected to reach only 618,663 based on average historical growth rates. This discrepancy will result in a significant decrease in population density from 89 persons per hectare in 2021 to 57 persons per hectare in 1450 indicating that physical growth is outpacing population growth, reflecting excessive horizontal expansion.
Population Capacity Assessment for the Urban Expansion of Zahedan by 1450
Estimating the population capacity of newly developed areas is essential for physical and service planning. In this study, population capacity was calculated based on the recommended density of 113 persons per hectare from the 2011 comprehensive plan.
The added urban area by 1450 is estimated at 3,521 hectares, allowing for an additional population capacity of approximately 397,968 persons. Therefore, the total population capacity of Zahedan by 1450 is projected to reach approximately 985,698 persons. This figure exceeds the expected population based on historical growth rates by nearly 300,000 persons.
This indicated that the amount of newly added urban land will more than accommodate future population growth, and no additional expansion of urban boundaries will be necessary. The projected density of 113 persons per hectare is considerably higher than the expected population density, suggesting that such a standard would lead to excessive horizontal expansion and unnecessary spatial dispersion of the city.
Discussion
In the present study, the extent of land-use pattern realization, its relationship with urban spatial expansion, and the future growth trajectory of the city were examined. The findings indicated that the physical (49.28%), environmental (46.30%), economic (43.40%), and managerial (38.10%) dimensions experienced the highest levels of development in Zahedan’s land-use pattern, whereas the socio-cultural dimension (32.26%) exhibited the lowest level of development. The socio-cultural dimension was among the most influential factors in shaping urban physical development, particularly in the formation of informal settlements. This dimension was itself affected by other parameters such as economic conditions. Neglecting employment opportunities, increasing rural-to-urban migration due to the absence of suitable rural employment, poverty, and unequal income distribution all contributed to the expansion of urban areas through the proliferation of informal settlements, an issue evident in Zahedan as well. Therefore, greater attention to socio-cultural dimensions is required to guide urban land-use patterns more effectively than other dimensions.
According to the results, the realization rate of the land-use plan in the Zahedan Master Plan was 41.86%, which was nearly average. Numerous studies have indicated that land-use realization rarely aligns with urban development plans or falls below anticipated levels. Similar findings have been reported by Ebrahimi Boozani and Zamani Joharestani (2021) in Malayer, and by Shokohi Bidhendi and Khaliji (2004), who have reviewed the reasons for the low realization of the Baneh Master Plan, concluding that many components of the plan had achieved less than 60% realization. Taghvaee and Mousavi (2007) have assessed the feasibility of the Mahyariz Development Plan, finding that physical and spatial development had exceeded 100%, indicating uncontrolled urban growth such that the city would have sufficient land capacity to accommodate population growth for the next 26 years. Overall, previous research on land-use patterns and the expansion of urban boundaries in development plans including studies by Khakpour et al. (2007), Movahed & Samadi (2011), Hoseyn Zadeh Dlir et al. (2010), Lotfi et al. (2004), and Zarabi et al. (2010) highlights inconsistencies and inefficiencies between actual land use and the intended development framework.
Land-use patterns, as one of the most sensitive subjects in urban planning, are not solely physical issues; rather, they encompass all social, economic, environmental, and managerial processes occurring within the city. It is therefore essential that comprehensive development plans, particularly master plans intended to guide holistic urban development, give adequate attention to these dimensions, as examined in this study. The enhancement of land-use patterns for the implementation of urban master plans requires specific principles that facilitate planning. These principles function as catalysts that help improve land-use patterns and enable the achievement of planning objectives.
The findings of this research highlighted the inherent limitations of all growth-modeling approaches, including the SLEUTH model, particularly its weak capacity to incorporate non-spatial and subjective factors such as cultural parameters and other elements that cannot be spatially or quantitatively represented. Consequently, the model outputs in this study could not fully reflect all determinants of urban growth in the simulation of Zahedan’s future expansion or in assessing land-use realization in development plans. Nonetheless, this research sought to mitigate these limitations by considering multiple influential factors in Zahedan’s growth through simulation and expert-based evaluation.
Modeling projections for 1450 (2071–72) indicated that, despite the urban growth observed between 1991 and 2021, the rate of physical expansion will decelerate in the forecast horizon. One major reason was the incorporation of Zahedan’s unique constraints and determinants of urban growth. Most land-requirement estimations employed simplistic calculations based solely on minimum per-capita land standards; however, this study considered critical contextual factors influencing Zahedan’s growth, supported by software-based analysis and expert judgement, to provide a more realistic representation of future land-use patterns.
As anticipated, the western areas of the city exhibited greater suitability and capacity for development, a result also supported by the model’s 1450 projections. Hence, the growth pattern of Zahedan reflects the influence of the criteria used in this study. Given the city’s arid desert climate, the projected expansion was not expected to harm the natural environment, as most surrounding barren lands will be converted into urban uses. However, in some areas, particularly the eastern zones, the projected pattern may lead to urban expansion into unsuitable areas with steep slopes or flood-prone channels. This would complicate the provision of urban services and the realization of proposed land-use patterns in future development plans.
Zahedan had a high proportion of informal and marginal settlements, predominantly in the eastern periphery and outside the official city limits. In addition, demographic statistics were sometimes inconsistent, making it difficult for official analyses to accurately reflect real-world growth patterns. In this study, efforts were made to ensure that land-use change detection and future growth modeling extended beyond administrative boundaries, incorporating larger settlement clusters. Modeling resulted to 1450 and population-absorption scenario calculations demonstrate a significant discrepancy between urban physical growth and population growth, primarily due to the absence of reliable demographic data and the excessive expansion of informal areas.
Based on the findings, urban sprawl cannot be properly understood without considering spatial patterns. While the methodology and model employed in this research differed from previous studies in Iran, they were consistent with international research conducted by Saxena & Jat (2019), Agyemang et al. (2022), and Li et al. (2018). Given the systemic and complex nature of urban development, driven by numerous intertwined factors it is recommended that future studies incorporate a wider range of parameters into modeling efforts, develop alternative environmental and socio-economic impact scenarios, and test multiple approaches to achieve more intelligent and accurate predictions of urban growth.
Conclusion
The weak performance of the social, economic, and managerial indicators in Zahedan has, to some extent, distanced the city from the objectives set out in its comprehensive physical development plan. Therefore, it is essential to identify the city’s needs and potentials in order to determine development capacities across different sectors. Overall, the findings indicate that the Zahedan Master Plan has achieved less than 50% of its intended goals. This shortfall can be attributed primarily to the lack of adequate attention to socio-cultural dimensions of urban development. Such issues, despite appropriate planning, can only be effectively addressed through the active participation of stakeholders and influential groups, ensuring greater realization and effectiveness of urban development plans.
Acknowledgments: No acknowledgments were reported by the authors.
Ethical Permissions: No ethical permissions were reported by the authors.
Competing Interests: The authors declare no conflicts of interest.
Authors’ Contributions: Akbari A (First Author), Introduction Writer/Main Researcher (50%); Eskandari Sani M (Second Author), Methodologist/Discussion Writer (30%); Esmaeilnezhad M (Third Author), Assistant Researcher/Statistical Analyst (20%)
Funding: This study was funded through the authors’ personal resources.
Keywords:
References
1. Agyemang FS, Silva E, Fox S (2022). Modelling and simulating 'informal urbanization': An integrated agent-based and cellular automata model of urban residential growth in Ghana. Environment and Planning B: Urban Analytics and City Science.0(0):1-15. [Link] [DOI:10.1177/23998083211068843]
2. Athari K (1994). Crisis of thought in Iran's contemporary urban planning. Iranian Journal of Architechtoral and Urbanism. 31-32:0-0. [Persian] [Link] [DOI:10.2307/4299904]
3. Behzadfar M (2004). Urban plans and programs. 2004. Tehran :Nashr-e Shahr. [Persian] [Link]
4. Clarke KC, Gaydos LJ (1998). Loose-coupling a cellular automaton model and GIS: Long-term urban growth prediction for San Francisco and Washington/Baltimore. International Journal of Geographical Information Science. 12(7):699-714. [Link] [DOI:10.1080/136588198241617]
5. Cohen B (2006). Urbanization in developing countries: Current trends, future projections, and key challenges for sustainability. Technology in Society. 28(1-2):63-80 [Link] [DOI:10.1016/j.techsoc.2005.10.005]
6. Ebrahimi Boozani M, Zamani Joharestani A (2021). An analysis of the feasibility of land use planning in the Malayer master plan. Journal of Urban Ecology Research. 12(2);119-137. [Persian] [Link]
7. Ebrahimzadeh I, Brimani F, Nasiri Y (2004). Slum -dwellers, solutions and its special-civil abnormalities case study: Karimabad Zahedan. Geography and Development. 2(3):121-146. [Persian] [Link]
8. Hoseyn Zadeh Dalir K, Pourmohammadi MR, Soltani AR (2010). Investigating factors affecting the inefficiency of Iran's urban master plans (case study: Tabriz master plan). Geography and Planning. 15(31):13-151. [Persian] [Link]
9. Jamshidzehi Shahbakhsh O, Ghanbari S (2020). Analysis of urban sprawl and its effects on the physical-spatial changes of peripheral villages of Zahedan. Journal of Urban Peripheral Development. 2(1):85-104. [Persian] [Link]
10. Jantz C, Drzyzga S. Maret M (2014). Calibrating and validating a simulation model to identify drivers of urban land cover change in the Baltimore, MD metropolitan region. Land. 3(3):1158-1179. [Link] [DOI:10.3390/land3031158]
11. Khakpour B, Velayati S, Kiyannekhad GH (2009). Pattern of land use change in Babol city years 1983-1999. Geography and Regional Development. 5(9):45-64. [Persian] [Link]
12. Li F, Wang L, Chen Z, Clarke KC, Li M, Jiang P (2018). Extending the SLEUTH model to integrate habitat quality into urban growth simulation. Journal of Environmental Management. 217:486-498. [Link] [DOI:10.1016/j.jenvman.2018.03.109]
13. Lotfi S, Pourjafar M, Ansari M (2004). A review on the ineffectiveness of the detailed designs common in context Residential organic (case of Imamzadeh ghasim neighborhood of Tehran). Fine Arts Magazine. 18(18). [Persian] [Link]
14. Movahed A, Samadi MH (2011). Quantitative and qualitative evaluation of land use in Marivan city. Human Geography Research Quarterly. 78:45-66. [Persian] [Link]
15. Nourian F, Vahidi Borji G (2015). Evaluation of land use planning in urban development plans based on needs assessment and location assessment indicators (Case study: Bojnord city). Town and Country Planning. 7(1):49-69. [Persian] [Link]
16. Pirzadeh H (2008). Reforming the urban development management system in Iran based on a strategic approach. 2008. Tehran: Ministry of roads and Urban Development Islamic Republic of Iran. [Persian] [Link]
17. Qomami M (1992). Overview of comprehensive urban plans. Abadi. 2(7). [Persian] [Link]
18. Rahnamaee MT, Shah-Hosseinin P (2007). The process of formation and growth of Iranian cities. Political and Economic Information. 21(9):220-231. [Persian] [Link]
19. Saxena A, Jat MK (2019). Capturing heterogeneous urban growth using SLEUTH model. Remote Sensing Applications: Society and Environment. 13:426-434. [Link] [DOI:10.1016/j.rsase.2018.12.012]
20. Sfandeh S, Danehkar A, Salman Mahini A (2021). Simulation and prediction of urban growth pattern until 2050 using SLEUTH-3R model (Case study: Coastal area of Parsian city). Journal of Environmental Studies. 47(1):65-88. [Persian] [Link]
21. Shokohi Bidhendi MS, Khaliji K (2010). An overview of the reasons for the non-fulfillment of comprehensive plans/case example: the comprehensive plan of Baneh city. The Iranian Journal of Landscape -Indexed in Web of Science. 1(4):31-35. [Persian] [Link]
22. Taghvaee M, Mousavi M (2007). Assessing the degree of realization of Mehriz city plan. Geographical Research. 23(3):63-80. [Persian] [Link]
23. Vahidi Borji G, Nourian F, Azizi MM (2017). The obstacles against the success of suggested functions in urban development projects in Iran. Honar-Ha-Ye-Ziba. 22(1):5-14. [Persian] [Link]
24. Zarabi A, Rashidi Nik S, GHasemi Rad H (2010). Analysis and evaluation of land use in Izeh city. Research and Urban Planning. 1(3):19-40. [Persian] [Link]
25. Zebardast E (2010). The application of analytic network process (anp) in urban and regional planning. Honar-Ha-Ye-Ziba. 2(41);79-90. [Persian] [Link]