Geografia

More than half of the world's population currently resides in urban areas. In the majority of developing countries slums are a defining part of the urban scape. Their supply with energy, basic infrastructure, among others is one of the main challenges of modern civilizations. To provide an optimal supply, the spatial patterns of slums in cities have to be explored. While most of current literature is focused on inter-urban dynamics, this paper is focused on intra-urban pattern (i.e. the spatial pattern of morphological slums within a city) and its link to the inter-urban ones. Therefore, census and remote sensing data are analyzed to create rank size distributions of morphological slums in different cities of developing countries. The observations were compared to rank size distributions of cities in a respective developing country. It is found that typical inter-urban pattern can be transferred to intra-urban pattern. Surprisingly is the fact that the size of slums is independent from city and global region in the analyzed cities. The slums in Mumbai, Manila, Rio de Janeiro and Cape Town have an average area of 0.016 km2 with a standard deviation of only 0.004 km2 .

Urban inequality is widely debated but few studies examine developments over time and across cities. In this contribution, we develop a novel approach to study the dynamics of inequality in cities of the Global South. Using a sample that includes cities in Africa, Latin America, and Asia, we track trends in equality since the 1990s in four domains: the labor market, education, private goods, and public amenities. With descriptive statistics, inequality indexes, and logistic regression analysis, we show that while inequality in educational attainment is decreasing across all cities in our sample, patterns in the other domains are more complex. Even though the middle occupational group is growing in most cities in our sample, there are important exceptions and substantial regional variations. While we find that inequality in material comfort more often decreased than increased, class position continues to predict access to both private goods and public amenities. Although the observed patterns are complex, we find no proof of escalating inequalities in the domains under study.

The Sustainable development goals (SDG) aim for reducing poverty (SDG 1) and to upgrade all slums (SDG 11). The first indicator in SDG 11 describes the proportion of the urban population residing in slums. However, the currently available data is based on national estimates that follow globally varying methodologies and concepts. In this paper, a uniform approach is implemented to obtain slum population estimates in eight different cities from three continents. The approach relies on earth observation datasets on the spatial extent of the slums and one of the most accepted gridded population dataset: WorldPop. The results shed light on the distribution of population in slums around the world. Nevertheless, the question of the accuracy of these population numbers arises. Therefore, a broad range of literature data containing population counts is gathered for the cities investigated, for varying years and for different spatial scales. The literature data is compared to results obtained by the presented approach. The comparison yields a plausibility assessment for different cities, indicating varying levels of deviation. We find in all cities a clear bias in estimating the slum population - mostly underestimations -, even though some cities reveal a significantly better fit to the data. In conclusion, this study provides a methodology to systematically assess the accuracy of globally available datasets in the context of slums and thereby to highlight the large uncertainties which can empirically be observed.

Existing studies on spatial justice discuss how different aspects of spatial injustices repeatedly deprive the poor and low-income urban dwellers of access to urban amenities. According to these studies, increasing equity in the allocation of urban resources for all categories of urbanites can remedy these injustices. However, land tenure security, a pre-condition for access to urban amenities for the poor and low-income urban dwellers, is hardly addressed. This study explores the potential of spatial justice to land tenure security discourse, using a metasynthesis of the literature on both concepts. It draws upon the Brazilian experience of implementing inclusive urban (re)development framework, which aims at integrating the poor and low-income urban dwellers in the urban fabric. Land tenure security is understood from the spatial aspect of social justice, rather than its traditional economic conceptualisation. We find that the pursuit of the three forms of spatial justice (alongside the processes of urban (re)development) promotes the three elements of tenure security differently. Procedural justice is identified as the main driver of land tenure security, whose prominent features are the perceived and the de facto tenure security.

Latin America is a highly urbanized region characterized by remarkable inequality levels, also reflected in an uneven distribution of opportunities, making socio-economic segregation quite visible. Since the individual possibility to travel and therefore access to urban opportunities strongly depends on socio-economic status and the distances to overcome, highly unequal patterns of mobility and accessibility emerge. The continuous expansion of Latin American cities originates specific mobility-related inequalities visible in periurban areas, which tend to lack some key urban opportunities and public transport services usually available in cities. Due to established and new patterns of territorial segregation, these areas may generate new forms of marginality in relation to mobility, posing challenges for public action and territorial governance. Our paper considers if and how periurban areas experience different forms of mobility-related inequalities in three Latin American metropolises in Brazil, Chile, and Colombia (São Paulo, Santiago, and Bogotá, respectively). We do so by examining the differences among urban core and periurban zones based on four elements: socio-demographic features, access to the public transport system, spatial continuity, and functional dependence. Our analysis shows that the three metropolitan regions have different structures: while Bogotá and Santiago appear to be more dependent on the urban core, São Paulo shows more autonomous and self-sufficient periurban zones. The analysis also highlights different forms of peripherality, defined by differentiated mobility patterns and modal choices that suggest that city-specific lines for public action might be needed.

Growing global low-income populations living in informal urban settlements need basic services to live healthy, productive, dignified lives, but their informal status presents a legal barrier to service extension. In this paper we explore the informal mechanisms or ‘negotiated institutions’ that emerge to overcome this barrier, and the resulting link between service extension and tenure security. Primary data was collected in São Paulo, Brazil through semi-structured interviews with water supply decision makers and two community-level case studies. Interviews identified four mechanisms for approval of service extension: two forms of ‘permission’ (non-opposition) at the municipal level, a local elected official signing a law (without legal standing) or a unique instance of victory in court. We argue that the factual circumstances of de facto tenure security have to be interpreted through the lens of the entity with the power to evict. Thus, the impact of ‘negotiated institutions’ on de facto tenure security depends on the level of political support. In this case, the use of informal mechanisms to extend services did not change legal tenure status but improved de facto and perceived tenure security. Understanding these ‘negotiated institutions’ and how they emerge is crucial to being able to harness them to the advantage of informal communities that lack access to basic services.

With over half of the world's population living in cities, and with rising consumption, the generation of solid waste has become a ubiquitous and serious problem in urban agglomerations. City administrations are facing social, cultural, environmental, and economic challenges when planning solid waste solutions. The paper discusses the participatory epistemology and methodology experience resulting from inclusive solid waste management in Brazil. In the global South countless informal and organized solid waste collectors are engaged in resource recovery, classification of discarded waste, and redirection of recyclables towards the recycling sector. Their work is mostly unrecognized and the service is not remunerated. Governmental support to include recycling cooperatives in selective waste collection varies significantly in scope and quality. In theory, the Brazilian solid waste management legislation supports recycling cooperatives and promotes avoidance, reuse, and recycling as a primary solution tackling waste. In praxis, however, many challenges towards inclusive resource recovery and awareness building about waste avoidance and diversion are yet to be overcome. Action-oriented, participatory qualitative research, conducted with recycling cooperatives and local governments in the metropolitan region of Sao Paulo, has revealed some of ~ the environmental and social contributions, as well as challenges arising in planning, policy design, and implementation of waste management. The research applies a feminist and post-colonial theoretical lense and demonstrates a wealth of knowledge co-generation on waste management. The participatory method underlines important social aspects to consider in planning and policy design for inclusive waste management. The final conclusion of this paper is that selective household waste collection with recycling cooperatives creates unique opportunities to build more inclusive and cleaner cities.

Slum identification and mapping are fundamental to support public policies. However, slum data is affected by differences in definition, identification, spatial delimitation, sample and data collection periods. This study compares slum maps in Sao Mateus (a peripheral region of Sao Paulo city) from the 2010 demographic census and the Sao Paulo municipal government. The census and the municipal basemaps and orthophotos were overlaid in a Geographic Information System (GIS) to evaluate their similarities and differences, the reasons for inconsistencies between them. Of the 68 districts with subnormal agglomerates (EDSAs; special enumeration districts for slum areas in the Brazilian demographic census), 59% are in the categories ‘high coincidence’ or ‘partial coincidence’ with the perimeters of favelas (the main type of slum in Brazil) delineated by the Sao Paulo municipal government; the names of the residential area (favela/EDSA) are the same in only 51.5% of the subnormal agglomerates, while 26.5% of the EDSAs include residential areas not considered favelas by the municipality. Many Brazilian researchers state that the underestimation of EDSA census data is accentuated by the exclusion of favelas smaller than 51 dwellings from the census. However, at least in Sao Mateus, the exclusion of small favelas (3.6%) was not the only reason for census underestimation of favelas.

Cities worldwide face the challenge of balancing densification and open space provision. However, few studies investigate how urban morphology influences that balance across different cities and continents. We identified eight urban morphological types characterizing high-density residential areas in São Paulo, Brasília (Brazil), and Berlin (Germany) and assessed those morphologies using seven indicators: population density, housing density, Floor Space Index (FSI), Ground Space Index (GSI), average building height, Open-Space Ratio (OSR), and average number of people per built area. Our findings from the Brazilian cities showed that intense verticalization does not automatically ensure open space and high density. Vertical morphologies showed the highest FSI values but not the highest housing densities, and had low to moderate OSR values, comparatively. Three morphologies found in Berlin (Contemporary, Half-Open and Edge) balanced housing density and OSR best (127–147 dwellings/ha, 0.5 to 0.8 OSR values, on average). Berlin’s Traditional type showed the best balance between FSI, GSI, average building height and OSR, with buildings ranging from 1 to 9 storeys. It also achieved the highest housing densities (188 dwellings/ha, on average), but at a cost of OSR. Those findings suggest that a compact city model with perimetral blocks (Half, Edge and Traditional types) could provide an optimum use of urban space, if open space provision is properly considered. We further discuss the advantages and implications of block-based urban planning and design (traditional in Berlin and other European cities) in contrast to plot-based (often observed in Latin American cities).

In the context of the complexities related to the expansion of the planet's urban areas and sustainability, the aim of this article is to analyze the Muepo/Riortas Project, an initiative developed between 1989 and 1996 by the Pontifical Catholic University of Rio de Janeiro (PUC-Rio) in partnership with the Brazilian National Agricultural Society (SNA) and Rio de Janeiro's Superintendency for the Environment. After conducting interviews with the coordinators and community leaders involved and analyzing technical reports produced by Rio's City Hall and PUC-Rio, the project's main lines of action were identified as the following: the political issues, sustainable soil productivity, range of vegetable species and economic viability of community allotments. The project addressed fundamental issues, such as the need for planning tools in order to guarantee the continuous production of a range of vegetable species over time and to maintain and expand the productive capacity of the soil through organic cultivation methods. The number of allotments established by the project was much lower than the 15 that were planned. Two units were opened during the period analyzed: the Allotment School and the Santa Cruz Community Allotment. Production at the Allotment School, located at the Wenceslau Bello School of Horticulture, involved the weekly harvest and sale of 250x2.5 kg vegetable bags for two years running. This was enough to guarantee the allotment's economic sustainability. The Santa Cruz Community Allotment, however, did not manage to achieve economic viability over the period analyzed. Technical issues associated with the planning and management of the soil were addressed well, but empowerment mechanisms and community involvement proved to be weak during the installation and maintenance of the allotment. In summary, the Muepo/Riortas Project has established new a paradigm for urban community allotments and should form the basis for any future multidisciplinary research seeking integrated solutions for the creation of more sustainable cities.