The Riyadh Urban Growth Boundary: An Analysis of the Factors Affecting its Efficiency on Restraining Sprawl

Recently, research on sprawl was increasing due to its impacts on the economy, society, and environment. Several studies have focused on the application of containment strategies to curb urban sprawl. Urban growth boundaries (UGBs) were among the containment policies adopted to tackle the issue of sprawling cities. This paper set out to undertake an analysis of the factors influencing the performance of the UGB of Riyadh City. A qualitative data analysis using NVivo12 software was adopted. To collect the required data of UGB, semi-structured interviews were conducted with nine experts involved in urban management, Riyadh city development, and other planning agencies. If the application of UGB policy in the western countries has managed to restrain more or less city sprawl, its replication to the case of Riyadh seems to have had some adverse impacts. That is, instead of controlling urban sprawl, it has stimulated it. The reasons may lie in the deficiency of monitoring and evaluation of urban studies, free provision of infrastructure, and lack of coordination between different city planning agencies. Understanding the factors affecting the UGB efficiency​will assist policymakers and urban planners in reducing the spread of scattered and leapfrog residential development, lowering the cost of service supply and promoting infill development

Automatic Delineation of Urban Growth Boundaries Based on Topographic Data Using Germany as a Case Study

Urban Growth Boundary (UGB) is a growth management policy that designates specific areas where growth should be concentrated in order to avoid urban sprawl. The objective of such a boundary is to protect agricultural land, open spaces and the natural environment, as well as to use existing infrastructure and public services more efficiently. Due to the inherent heterogeneity and complexity of settlements, UGBs in Germany are currently created manually by experts. Therefore, every dataset is linked to a specific area, investigation period and dedicated use. Clearly, up-to-date, homogeneous, meaningful and cost-efficient delineations created automatically are needed to avoid this reliance on manually or semi-automatically generated delineations. Here, we present an aggregative method to produce UGBs using building footprints and generally available topographic data as inputs. It was applied to study areas in Frankfurt/Main, the Hanover region and rural Brandenburg while taking full account of Germany’s planning and legal framework for spatial development. Our method is able to compensate for most of the weaknesses of available UGB data and to significantly raise the accuracy of UGBs in Germany. Therefore, it represents a valuable tool for generating basic data for future studies. Application elsewhere is also conceivable by regionalising the employed parameters.

Future of the Fringe

Peri-urban landscapes are some of the world’s most vulnerable areas. Although they are often thought of simply as land awaiting development, these landscapes retain important natural resources and make valuable contributions to agriculture, water use, biodiversity conservation, landscape preservation and human well-being. Billions of people use them and enjoy their natural values. Their continuing loss threatens to alter our relationships with nature and have a negative impact on the environment. The Future of the Fringe first explores the history of peri-urban areas, international peri-urban policy and practice, and related concepts. It analyses internationally relevant issues such as green belts and urban growth boundaries, regional policy, land supply and price, and the concepts of liveability, attractiveness, well-being and rural amenity. It then examines a range of Australian peri-urban issues, as an extended case study. The book argues for a precautionary approach so that we retain the greatest number of options to adapt during rapid and unprecedented change.

Delineation of Urban Growth Boundaries Using a Patch-Based Cellular Automata Model under Multiple Spatial and Socio-Economic Scenarios

The urban growth boundary (UGB) plays an important role in the regulation of urban sprawl and the conservation of natural ecosystems. The delineation of UGBs is a common strategy in urban planning, especially in metropolitan areas undergoing fast expansion. However, reliable tools for the delineation of informed UGBs are still not widely available for planners. In this study, a patch-based cellular automaton (CA) model was applied to build UGBs, in which urban expansions were represented as organic and spontaneous patch growing processes. The proposed CA model enables the modeler to build various spatial and socio-economic scenarios for UGB delineation. Parameters that control the patch size and shape, along with the spatial compactness of an urban growth pattern, were optimized using a genetic algorithm. A random forest model was employed to estimate the probability of urban development. Six scenarios in terms of the demand and the spatial pattern of urban land allocation were constructed to generate UGB alternatives based on the simulated urban land maps from the CA model. Application of the proposed model in Ezhou, China from 2004 to 2030 reveals that the model proposed in this study can help urban planners make informed decisions on the delineation of UGBs under different scenarios.

Delineation of Urban Growth Boundaries with SD and CLUE-s Models under Multi-Scenarios in Chengdu Metropolitan Area

For megacities experiencing rapid urbanization in China, urban growth boundaries (UGBs) have been considered as a useful means to control urban sprawl and to promote sustainable urban development. However, scientific methods and tools to delineate sound UGBs by planners are few and far between. Using metropolitan Chengdu as the study area, this paper applies the system dynamics (SD) and conversion of land use and its effects at small region extent (CLUE-s) models to delineate UGBs. In this study, land use demand was simulated in the SD model temporally at a macro-level and allocated in the CLUE-s model spatially at a micro-level. Key social-economic elements and spatial pattern factors were used in the simulation process for the period of 2013–2030. The simulation results under various scenarios showed that areas along the major corridors and belt roads of the main Chengdu metropolitan area and its satellite towns have higher chances to be developed. The areas most likely to be developed were used to establish the UGBs for 2020, 2025, and 2030. This research demonstrates that the integrated framework of SD and CLUE-s models provides a feasible means of UGB delineation under different development scenarios.