A taxonomy of informality: exploring block types in five informal settlements in East Africa

Approximately 13% of the world population lives in informal settlements, characterized by limited state control, inadequate infrastructure provision, and lack of planning. While the relevance of studies of informal settlements is widely acknowledged, the urban morphology of such areas is understudied, compromising the development of effective planning and policy targeting such areas. In this paper, we present a taxonomic study at a fine level of spatial granularity of the urban form of five informal settlements, located in major cities of Sub-Saharan Africa. More specifically, a k-means clustering is applied to eight indicators of urban form computed at block level, for each of the settlements under examination. The best clustering identified ten different block types associated with distinctive features, such as blocks on public spaces (small, densely built, abundant public open space), fringe blocks (medium-sized, sparsely built, low local connectivity), blocks in the making (large, sparsely built, high levels of through movement at settlement level). We argue that this taxonomy provides detailed information about the case studies under examination, which can potentially inform design strategies aimed at their upgrading. Finally, it presents some of the first attempts at establishing replicable quantitative data driven descriptions of the urban form of informal settlements

Urban density and socioeconomic characteristics of informal settlements : evidence of interrelation from Maputo, Mozambique

Several studies have documented extensive low-density urban expansion of cities in sub-Saharan Africa, exacerbating issues of inadequate infrastructure, limited mobility and human impact on the environment. However, the relation between socioeconomic factors and urban expansion trends in sub-Saharan Africa remains understudied. This study investigates the links between household socioeconomic status and urban form of informal settlements based on case studies in Maputo, Mozambique. The findings of the study underscore that (1) built densification occurs over time, reflecting an incremental house expansion process enabled by household economic resources; (2) households with higher socioeconomic status consume comparatively more land, contributing to urban expansion; (3) households in more recently established settlements within the city limits have higher socioeconomic status than households in older settlements located in comparable proximity to the city centre; and (4) rental housing is more widespread in the centrally located settlements and accommodates younger residents with lower socioeconomic status

La historia de la ciencia como herramienta para la enseñanza de física en secundaria : un ejemplo en calor y temperatura

In this work we suggest and analyze some stages of a course on heat and temperature which knowledge of the past of the ideas and the solution provided can enable a better understanding of the content. The hypothesis that guided the planning of activities was that the scientific content studied throughout its history comes closer to the cognitive universe, not only of the student, but of man himself

Plot-based urbanism and urban morphometrics : measuring the evolution of blocks, street fronts and plots in cities

Generative urban design has been always conceived as a creation-centered process, i.e. a process mainly concerned with the creation phase of a spatial transformation. We argue that, though the way we create a space is important, how that space evolves in time is ways more important when it comes to providing livable places gifted by identity and sense of attachment. We are presenting in this paper this idea and its major consequences for urban design under the title of “Plot-Based Urbanism”. We will argue that however, in order for a place to be adaptable in time, the right structure must be provided “by design” from the outset. We conceive urban design as the activity aimed at designing that structure. The force that shapes (has always shaped) the adaptability in time of livable urban places is the restless activity of ordinary people doing their own ordinary business, a kind of participation to the common good, which has hardly been acknowledged as such, that we term “informal participation”. Investigating what spatial components belong to the spatial structure and how they relate to each other is of crucial importance for urban design and that is the scope of our research. In this paper a methodology to represent and measure form-related properties of streets, blocks, plots and buildings in cities is presented. Several dozens of urban blocks of different historic formation in Milan (IT) and Glasgow (UK) are surveyed and analyzed. Effort is posed to identify those spatial properties that are shared by clusters of cases in history and therefore constitute the set of spatial relationships that determine the morphological identity of places. To do so, we investigate the analogy that links the evolution of urban form as a cultural construct to that of living organisms, outlining a conceptual framework of reference for the further investigation of “the DNA of places”. In this sense, we identify in the year 1950 the nominal watershed that marks the first “speciation” in urban history and we find that factors of location/centrality, scale and street permeability are the main drivers of that transition towards the entirely new urban forms of contemporary cities

Exploring the similarities between informal and medieval settlements : A methodology and an application

Most urban growth is taking place in the developing countries of the Global South through informal settlements. This form of development is usually strongly opposed by governments and local administrations. However, several works compared them to vernacular urban centres, such as medieval towns, and praised their human-scale qualities. If this similarity were to be systemically assessed on a larger scale, informal settlements would gain more recognition and legitimation. This, in turn, can potentially impact policy making. In this paper, we propose a replicable methodology based on the use of open data to investigate similarities between informal and medieval settlements, through statistical comparison of metrics of urban form and correlation analysis between densities of amenities and street centrality (a fundamental relationship at the basis of city functioning). This methodology is tested on three informal settlements in Sub-Saharan Africa and three Italian medieval towns. Statistical similarities were found, especially for what concerned aspects of the urban fabric, configurational features, and the relationship between densities of amenities and street centrality. These findings add to the studies that recognise the value of informal settlements. Furthermore, the proposed methodology can be replicated to increase the generalisability of this result and further legitimise informal urban development

Diachronic investigation of the urban form of Qom (Iran) through morphometric approach

Qom is one of the oldest cities in Iran, with a multi-millennial history dating back to the 4th millennium BC, according to archaeological excavations. Due to different dominations (from ancient Persian dynasties to Islamic ones), the city has gone through successive phases of development and decay, which stratified in its urban form. More recently, due to its advantageous geographical position, several inter-city roads were constructed to converge in Qom, creating a radial structure, whose accessibility has been constantly improved by adding ring roads and filling gaps with local gridded networks. The sum of these transformations produced over time a complex urban form, which remains largely understudied. The aim of this paper is to investigate the morphology of Qom in a systematic manner through the use of a novel method of morphometric analysis based on multiple indicators of urban form describing aspects of the urban fabric and street network, as well as clustering techniques identifying homogeneous urban types in a hierarchical structure according to similarity. The application of this method to official datasets of plots and street segments, provided by the local administration, reveals 11 urban types with distinctive morphological traits, seemingly matching main phases of urban development. This morphometric analysis provides novel insights on one of the most ancient Iranian cities and can be replicated to investigate urban types in further case studies

Exploring the form of a Smart City district : a morphometric comparison with examples of previous design models

In key moments of urban history, urban design is confronted with the emergence of new paradigmatic design models, such as the garden city and the radiant city. Recently, the Smart City seems to have gained centre stage in the public debate. However, despite its emblazoned technological features, the Smart City remains a hazy concept in the urban design domain to such an extent that almost any form can be built under the Smart City label. While this may sound libertarian and progressist, it is also concerning since different urban forms are associated with different societal outcomes. This paper aims to investigate the forms of Smart City districts through morphometric comparison. More specifically, it proposes a replicable methodology based on 18 metrics of urban form and statistical analysis to compare a Smart City district with other city areas with known design models of reference. Such a methodology is applied to three case studies on the French Riviera: Méridia, a Smart City district, Hôtel-des-Postes, a 19th-century traditional district, and Sophia Antipolis, a sprawling technopark. The results show that Méridia has a hybrid form that partly resembles Hôtel-des-Postes (higher densities, gridiron plan, and functional mix) and partly Sophia Antipolis (bulky buildings with large setbacks). However, the top–down approach used in the production of the physical space ultimately renders Méridia more similar to Sophia Antipolis than Hôtel-des-Postes. This study provides one of the first morphometric characterisations of a Smart City district, but also a replicable methodology that can further the morphological understanding of the Smart City phenomenon worldwide

Urban form and COVID-19 cases and deaths in Greater London : an urban morphometric approach

The COVID-19 pandemic generated a considerable debate in relation to urban density. This is an old debate, originated in mid 19th century’s England with the emergence of public health and urban planning disciplines. While popularly linked, evidence suggests that such relationship cannot be generally assumed. Furthermore, urban density has been investigated in a spatially coarse manner (predominantly at city level) and never contextualised with other descriptors of urban form. In this work, we explore COVID-19 and urban form in Greater London, relating a comprehensive set of morphometric descriptors (including built-up density) to COVID-19 deaths and cases, while controlling for socioeconomic, ethnicity, age and co-morbidity. We describe urban form at individual building level and then aggregate information for official neighbourhoods, allowing for a detailed intra-urban representation. Results show that: (i.) control variables significantly explain more variance of both COVID-19 cases and deaths than the morphometric descriptors; (ii.) of what the latter can explain, built-up density is indeed the most associated, though inversely. The typical London neighbourhood with high levels of COVID-19 infections and deaths resembles a suburb, featuring a low-density urban fabric dotted by larger free-standing buildings and framed by a poorly inter-connected street network

What kind of neighbourhoods will people pay more for?

This article reviews the evidence on links between value and built form or use in a range of separate categories related to streets: patterns, types and uses. The aim is to examine the evidence around these categories, to help answer the question about how best to inter-weave connectivity and accessibility with everyday life in a way that would appear to work for most residents most of the time and also deliver value to investors and owners in the medium to long term. Some key lessons emerge from the literature review of relationships between place and value that tend to be true most of the time. Ultimately, most people will pay more for a well-connected property away from too much noise, pollution and one waystreets and within walking distance of local amenities