Dispersed Urban Development Research Articles

Can spatial patterns mitigate the urban heat island effect? Evidence from German metropolitan regions

This study examines the efficacy of urban spatial patterns at alleviating the urban heat island (UHI) effect in Germany’s city regions ( Großstadtregionen) using multivariate and non-parametric regression methods. Urban spatial patterns are quantified using five landscape metrics that capture the spatial arrangement of urban footprints and greenspaces, along with a polycentricity index that measures the distribution of human activities. The results indicate that certain features of urban fabric, including fragmentation, mixed land use, and regular-shaped urban patches, have the potential to mitigate the UHI effect. Moreover, dispersing multiple smaller greenspaces throughout the urban area demonstrates a greater cooling effect compared to having a single large and more aggregated park. In addition, our analysis reveals that a doubling (100%) of the polycentricity degree corresponds to a significant decrease in both day- and night-time UHI effects, with reductions of 10.4% and 24.6%, respectively. This study confirms that polycentric development yields greater benefits in reducing urban heat for large-sized city regions compared to medium- and small-sized ones; and its effectiveness is mostly pronounced near urban center(s). These findings suggest that polycentric development represents an efficient and feasible strategy for urban thermal planning of large-sized city regions, surpassing other commonly discussed urban configurations, such as compact or dispersed urban development.

Modelling spatial–temporal expansion of Lilongwe City using Shannon’s entropy model through semi-dynamic environmental mapping and analysis

This study involves analysis of the urban spatial–temporal expansion of Lilongwe City from 1973 to 2020 using Shannon’s entropy model through time-series satellite mapping. Landsat images from 1973 to 2020 in a nearly 10-year interval are used to determine spatial–temporal land use/cover changes. The city is zoned into 1 km concentric rings and four pie sections to determine both directional and spatial urban expansion trends while Shannon’s entropy model is employed to determine the degree of dispersity of the city’s sprawl. A linear regression model incorporating population as an explanatory variable is then applied to predict the spatial expansion trends for Lilongwe City. Results show that the built-up area in Lilongwe City expanded by 465.4% (9.9% per year) from 1973 to 2020, making it the second-largest land use/cover type in the city, after vegetation. Consequently, vegetation cover decreased by − 32.7% (− 0.7% per year) during the same period. High relative entropy indices (> 0.9) obtained from Shannon’s entropy model indicate a dispersed urban development for the city during the entire period of study. The North-West quadrant of the city has the highest proportion of urban expansion while the North-East quadrant has the lowest proportion, in a relative sense. Regression model predictions show that the city will most likely continue to expand by the year 2023 and then increase exponentially by the year 2033, due to high population growth. The results of this study will assist city authorities to control the expansion of the city and anticipate patterns for future urban sprawl.

The influence of landscape structure on the diversity of avifauna species in tropical urban areas of Northeastern Zimbabwe

ABSTRACT Variations in avifauna species diversity are subject to environmental factors as well as interactions with other species. We evaluated how landscape structure can influence the composition and distribution of avifauna species groups in a tropical urban landscape from the understudied region of the Harare metropolitan area in Northeastern Zimbabwe. We sampled avifauna species groups and computed patch metrics (size, shape and isolation distance) using remotely sensed data from 35 census plots representing five land use/land cover classes. Using multivariate analysis techniques, we found three habitat patch characteristics distinguishing avifauna species diversity and distribution, namely patch shape complexity (R2 = 0.47–0.64), patch size (R2 = 0.55–0.62) and isolation distance (R2 = 0.73–0.78). In this study, we discuss the implications of these findings with a view to better understanding the effects of urban landscape structure on avifauna species diversity in this understudied region. In particular, contextual landscape features such as native savanna vegetation accompanied by dispersed urban development patterns could mitigate the negative impacts of urbanization on biodiversity. This study may be useful in helping to understand landscape structure–biodiversity linkages in ecosystems outside tropical savannas, as well as in other urban areas of sub-Saharan Africa. Key policy insights provide empirical information for review of town planning by-laws and align zoning proposals to habitat requirements of avifauna species, inform preparation of environmental action plans to restore degraded landscapes and ecosystems and, inform development of subdivision layout design guidelines by managing the size, shape, isolation distance and LULC composition of habitat fragments.

The Social Cost of Urban Sprinkling

Low-density dispersed urban development, known as “sprawl” or “sprinkling”, is an alternative configuration that best expresses the structure of the Italian urban system and is taking on increasingly significant dimensions. This phenomenon has increased in recent decades due to a weakening of the urban agglomeration force that had characterized the first half of the last century. Partial abandonment of agricultural activities and socio-economic changes led to the progressive urbanization of rural areas and the birth of widespread cities. This work discusses the externalities generated by sprawl, focusing on the tangible costs that this urban development model unloads on the people. In particular, the territory of the Basilicata Region is analyzed. Based on the data of some municipalities in the region, a relationship between the marginal costs relating to the greater linear infrastructure that sprinkling requires and an index already described in the literature to provide a quantitative measure of this phenomenon was built and verified with a regression model.

Governance and policy limitations for sustainable urban land planning. The case of Mexico

In the last 25 years, unplanned and dispersed urban development has become the norm rather than the exception mostly in medium and small cities of the global south, a region with high poverty rates and weak institutions in charge of land use changes. This paper is based on environmental discourses and governance policy integration to address the limitations in preventing the conversion of open land, which provides ecosystem services, into settlement land. It analyzes the case of the Metropolitan Zone of Queretaro in central Mexico, which has experienced particularly high rates of urban expansion in recent years. This paper focuses on the private sector's significant contribution to urban sprawl, a situation linked to the following deficits: policy domain integration deficit, which is related to competing goals among multi-level, multi-scale and multi-sector actors; the interdisciplinary deficit, which requires various procedures and instruments to promote stakeholder collaboration; and the democracy deficit, which involves micro-level actions rather than substantive policy design to encourage citizens to become agents of change and develop awareness of the value of nature in cities.

Assessment of urban growth using Shannon’s Entropy Index: A case study of Chennai, Detroit of India

The Remote Sensing (R/ S) and Geographical Information System (GIS) play a vital role to evaluate and study the urban expansion pattern. In this study, the Chennai city was selected to perform the urban sprawl study. Five different periods of satellite imageries for the time elapsed between 1994 and 2016 were used. The main aim of this paper was to identify the urban sprawl of Chennai as a patterning process. The extended areas of urban in the period of 1994, 2001, 2006, 2011 and 2016 were extracted by the sub-pixel classification method from the satellite imageries. Furthermore, Shannon’s entropy index was used for assessing urban expansion. The findings of this study proved that Chennai city has sprawled by urban expansion during the period between 1994 and 2016. Likewise, the dispersion rate of urban sprawl for the periods of 1994, 2001, 2006, 2011 and 2016 were 0.671, 0.679, 0.688, 0.693 and 0.695 respectively. Consequently, this uncontrolled dispersed urban development had resulted in the study area losses their green space.

Territories -in- between

Territories -in- between

From Dispersed Urban Areas to Territories- in-between

The dissertation began with the observation that there is an increasing body of literature suggesting that the conventional idea of a gradual transition in spatial structure from urban to rural does not properly reflect contemporary patterns of urban development and their potential for sustainable development. Furthermore, it was argued that large parts of the urbanised areas of Europe are dispersed and that these are neglected in urban and spatial planning policies. Such areas tend to be labelled simply as sprawl, though there is little evidence about whether such dispersed development is more or less sustainable than other forms of urban development. Moreover, evidence points in the direction that large amounts of dispersed urban development ask for different planning instruments which reflect the complexity and network structure of theses specific settlement patterns. At the turn of the millennium and across Europe, concepts describing dispersed urban areas, like Zwischenstadt, città diffusa or tussenland gained some attention. They share an understanding of design and planning for the territory based on seeing the ‘urban landscape as a large interlocking system rather than as a set of discrete cities surrounded by countryside’ (Bruegmann, 2005). Nevertheless, none of the concepts influenced mainstream planning policy beyond a few individual plans and projects. To summarise, there is a limited understanding of the nature of dispersed urban development, uncertainty about how the sustainability of such areas can be assessed, and few policy instruments that would achieve any sustainability potential they offer. The dissertation sets out to contribute to an improved understanding of these issues by answering the following three research questions. 1. What spatial structures characterise dispersed urban areas in Europe? 2. Which morphological and functional structures of dispersed urban areas offer the potential for more sustainable development? If so, how can this potential be mapped and measured to inform regional planning and design? 3. Are there similarities and dissimilarities concerning potentials of dispersed urban areas in different locations, planning cultures, topographies and histories?

What drives land take and urban land expansion? A systematic review

Land take is the transformation of agricultural, natural and semi-natural spaces into urban and other artificial uses. It is closely linked to urban sprawl (low-density or dispersed urban development). Land take is a major environmental challenge, especially for biodiversity conservation, as it destroys and fragments natural habitats.In order to assess how the scientific literature dedicated to this topic adresses the determinants of land take, we analyzed 193 scientific articles retrieved through a systematic methodology.We summarized the causal relationships identified between land take and different explanatory factors. Among them, population and income growth, as well as the development of transport infrastructure and automobile use, are widely studied drivers that are most often found to increase land take. Political and institutional factors are extensively mentionned in the literature, suggesting that urban sprawl is not a mere result of “market forces” but is also shaped though public policies. Weak or unadequate planning, subsidies for land consumption and automobile transportation are said to increase urban sprawl, while infrastructure pricing and subsidies for urban renewal would have the opposite effect. The institutional setting, especially administrative fragmentation, reliance on local taxes, and competition between local jurisdictions, is suspected to be a major determinant of land take. The effect of many factors however remains relatively undocumented or controversial in the reviewed literature, including widely used policy instruments.

Urban sprawl: Extent and environmental impact in Baguio City, Philippines

Urban sprawl has emerged as a striking characteristic of recent global urban development. Land use policies advocating urban expansion for residential use to the detriment of a critical environment as in the case of Baguio City, Philippines, have shaped and reinforced the urban sprawl phenomenon. Urban sprawl is characterized by discontinuous, fragmented/leapfrog development, with random population densities. There are generally few studies regarding the environmental impact of urban sprawl and it is along this vein that this study was undertaken. The purpose of the study is to gauge how extensive urban sprawl has grown in Baguio City via Shannon?s entropy model and to explore its impact on the city?s environment. The result of the study revealed that urban sprawl prevails over the city?s physical development. The proximity of the entropy value to the maximum reference value, indicate a highly dispersed urban development attributed to the continuous increase in population, coupled with the physical constraint of topography and its limited land area. The most critical issue challenging the local government of Baguio City and its people is the creation of a Long Term Development Plan that should strike a balance between local ambitions, demographic facts, and the environmental sustainability.

Assessing the effects of applying landscape ecological spatial concepts on future habitat quantity and quality in an urbanizing landscape

This study develops a quantitative approach to evaluate the application of design concepts that link landscape ecology theory to landscape planning. Landscape ecology principles were used to develop spatial concepts for creating an armature of open space in areas subject to rapid urbanization. It focuses on the predicted urban expansion of Damascus, Oregon, as a case study. An alternative futures study was used to test three open space spatial concepts for patches, corridors and networks contrasted with compact and dispersed urban development patterns. Eight scenarios of land use and land cover, over 50 years, were defined based on different spatial design concepts to evaluate their effects on habitat quantity and quality and analyze the tradeoffs between urban development and conservation of three focal wildlife species: red-legged frog, western meadowlark, and Douglas squirrel. Open space spatial concepts highly influenced habitat quantity and quality differences among scenarios. Development patterns showed lower influence on those variables. Scenarios with no landscape ecological spatial concept provided the most land for urban development but reduced habitat quantity and quality. Greenway scenarios presented increases of habitats, but failed to provide sufficient habitats for western meadowlark. Park system scenarios also presented an increase on the amount of habitats, but high-quality habitats for western meadowlark and red-legged frog decreased. Network scenarios presented the best overall amount of habitats and increase of high-quality habitats for the three species, but constrained urban development options.

Spatio-temporal Analysis of Urban and Population Growths in Tripoli using Remotely Sensed Data and GIS

The remote sensing data and GIS have been used widely to analyse and study the patterns of urban expansions. The capital of Libya, Tripoli was selected to perform this study and to examine its urban growth. Four satellite imageries and population censuses of the study area for the time period 1984 to 2010 were used in this work. The objectives of this paper are identifying and analysing the urban sprawl of Tripoli as a pattern and as process. Also to understand and assess the interchangeable relationship of urban growth and population growth of study area. Urban area extents in different time periods were extracted by supervised classification method of the satellite imageries. Then, the population data and urban extents data were coupled to perform the analysis. Additionally, Shannon's entropy technique was used for further assessment of urban growth. The study findings demonstrate that Tripoli had sprawled urban growth during the period 1984 to 2010. Moreover, during the above mentioned period, the urban expansion dispersion rate has shown in an ascending mode. Consequently, this uncontrolled dispersed urban development had resulted in high consumption land rate per capita despite of decrement in population growth rate.

Spatio-temporal Analysis of Urban and Population Growths in Tripoli using Remotely Sensed Data and GIS

The remote sensing data and GIS have been used widely to analyse and study the patterns of urban expansions. The capital of Libya, Tripoli was selected to perform this study and to examine its urban growth. Four satellite imageries and population censuses of the study area for the time period 1984 to 2010 were used in this work. The objectives of this paper are identifying and analysing the urban sprawl of Tripoli as a pattern and as process. Also to understand and assess the interchangeable relationship of urban growth and population growth of study area. Urban area extents in different time periods were extracted by supervised classification method of the satellite imageries. Then, the population data and urban extents data were coupled to perform the analysis. Additionally, Shannon's entropy technique was used for further assessment of urban growth. The study findings demonstrate that Tripoli had sprawled urban growth during the period 1984 to 2010. Moreover, during the above mentioned period, the urban expansion dispersion rate has shown in an ascending mode. Consequently, this uncontrolled dispersed urban development had resulted in high consumption land rate per capita despite of decrement in population growth rate.

Exploring long-term land cover changes in an urban region of southern Europe

This paper addresses two important issues for large Mediterranean city regions: the differential impact of compact urban ‘growth’ and low-density ‘sprawl’ on land cover changes (LCCs), and their final effect on changing land cover relationships (LCRs). The urban expansion of Rome (Italy) during the last 50 years and the related LCCs were investigated as a paradigmatic example of compact versus dispersed urban development. LCCs were assessed over 5 years (1960, 1974, 1990, 2000, 2006) by analysing diachronically the distribution of 12 land cover categories derived from digital land cover maps covering the entire Nuts-3 prefecture of Rome (5353 km2). LCRs were studied using multi-way data analysis. LCCs were found to have relative differences during ‘growth’ (1960–1990) and ‘sprawl’ (1990–2006) phases. Conversion to urban land uses concentrated in the 1960s and 1970s at the urban fringe, while expanding progressively far from the city in the 1990s and 2000s. During the ‘growth’ phase, the land cover classes with the highest probability of being converted to urban uses were arable lands, annual crops, vineyards and pastures. During the ‘sprawl’ phase, olive groves, orchards and forest surfaces also decreased due to the development of low-density built-up areas and infrastructure. Planning suggestions aimed at mitigating the alteration of the rural landscape through sprawl conditions are discussed.

Urban permeation of landscapes and sprawl per capita: New measures of urban sprawl

A B S T R A C T Urban sprawl (dispersed urban development) has increased at alarming rates in Europe and North America over the last 50 years. Quantitative data are urgently needed in monitoring systems for sustainable development. However, there is a lack of reliable measures of urban sprawl that take into account the spatial configuration of the urban areas (not just total amount). This paper introduces four new measures of urban sprawl: degree of urban dispersion (DIS), total sprawl (TS), degree of urban permeation of the landscape (UP), and sprawl per capita (SPC). They characterize urban sprawl from a geometric point of view. The measures are related through TS = DIS ! urban area, UP = TS/size of the landscape studied, and SPC = TS/number of inhabitants. The paper investigates the properties of the new measures systematically using 13 suitability criteria which were derived from a clear definition of urban sprawl as discussed in a previous paper. The scale of analysis is specified by the so-called horizon of perception. Second, the new measures are applied to threeexamplesfromSwitzerland.Subsequently,themeasuresarebrieflycomparedtoothermeasuresof urban sprawl from the literature. We demonstrate that UP is an intensive and area-proportionately additivemeasure andissuitableforcomparingurban sprawlamong regionsofdifferingsize, whileSPCis most appropriate when comparing sprawl in relation to human population density. The paper also provides practical advice for calculating the new measures. We conclude that the new method is more suitable than previous methods to quantify the indicator ‘‘urban sprawl’’ in monitoring systems as this method distinguishes the phenomenon of urban sprawl from its various causes and consequences. This article is part II of a set of two papers.