Solo urbano

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 .

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.

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.

The city of Curitiba, Brazil, is considered an exceptional model of sustainable urban planning. It has received praise for its invention of the Bus Rapid Transit System and numerous awards identify Curitiba as one of the world's greenest cities. Controversial elements have, however, been left out of this hegemonic city discourse, along with inevitable new challenges. The aim of this article is two-fold. First, we assess whether Curitiba is living up to its reputation as a leading sustainable city by analyzing three areas of urban sustainable development: green spaces, water bodies and public transportation. We show how Curitiba experiences problems ranging from social exclusion resulting from green space policies, to polluted water bodies and hampered planning in the area of public transportation. Second, we examine how the Curitiba discourse as a leading sustainable city is able to endure in this changed material context. We demonstrate how this hegemonic discourse prevents institutional transformations: the discourse becomes reproduced by powerful networks and propaganda, masking new unsustainable realities and by the same token preventing fast and successful institutional renewal.

Small municipalities are key to reducing waste and tackling climate change, but they often struggle to innovate and improve their capacity to deliver public services, especially in developing countries. This article explores how small municipalities can innovate in public service provision despite limited resources. Specifically, we analyzed municipal solid waste management (MSWM), a service typically overseen by municipalities and essential for reducing greenhouse gas (GHG) emissions. The study is based on a single case: Harmonia, a small Brazilian municipality selected for its exceptional waste recovery performance – the highest in the country – alongside composting and prevention initiatives. Following an economic and environmental assessment of MSWM effectiveness, including GHG emissions, the Multi-Level Perspective (MLP) was applied to analyze the political, social, and institutional factors that enabled innovation in Harmonia’s MSWM system. Findings suggest that successful innovation in small municipalities tends to rely on small-scale initiatives that require neither advanced technologies nor major investments. However, this depends on long-term support from a landscape of actors and public policies to scale up and coordinate efforts across departments, overcoming resource limitations. In Harmonia, the effectiveness of prevention actions, home composting, and recycling was rooted in decades of environmental education, social engagement, public awareness, and collaboration with other levels of government. These technological and management efforts led to costs (US$24.40 per inhabitant/year) and emissions (37.02 kg CO2eq per inhabitant) significantly below the national average (US$35.70 and 396.83 kg CO2eq per inhabitant, respectively).

This paper is about changes in people's perceptions relating to security of land tenure in Recife, Brazil. This paper investigates why people living in contested settlements invest and consolidate their houses despite the apparent lack of land tenure security. The question is very simple, but the answer is highly complex. Although the topic has been widely researched, there is still insufficient understanding of what security means to individual households, and how security influences the consolidation and improvements of houses. Households invest in all kinds of processes and commodities to improve their plots, and their houses, and inevitably this changes their perceptions of security. Data were mainly gathered from in-depth interviews held with a total of 63 households living in five different informal settlements in Recife. The paper focuses on the informal claims made by households about their perceived rights over their property, since for the great majority of the households living in these settlements, property rights in the form of title deeds are not available. The key aspects highlighted in this papers are that (1) the lack of a better understanding about what tenure really means to low-income households can pose threats to the survival of low-income housing markets, and (2) contrary to orthodox knowledge, the paper contends that perceptions of tenure security increase as a result of housing consolidation.

The main purpose of this paper is to ascertain whether the concession of real right to use (CRRU) has been widely applied by Brazilian municipalities, and the extent to which beneficiaries (individuals living in regularised low-income settlements) make effective use of such an instrument to secure tenure status. Another relevant aspect is to review the relationship between securing land tenure and the use of land as collateral for investment. It is hoped that the paper can be used as the basis for a longitudinal study to monitor progress in the provision of secure tenure for the urban poor in Brazil, by investigating the strengths and weakness of CRRU to the formulation and implementation of pro-poor urban land tenure policies. Findings indicate that municipalities have to overcome problems related to the implementation of these programmes, such as; resistance on the part of the judiciary (at the municipal level) to incorporate newly acquired rights; the need to change attitudes towards the legalisation process of occupied land; and the need to change residents’ perceptions of this new instrument. The success of CRRU can depend on the articulation of these issues, as well as more integrated actions among planners, lawyers, city managers, and the residents of these settlements to advance performance.

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.

The city of São Paulo, home to 11 million people, suffers constantly the effects of  flooding caused by extreme precipitation. Localized floods occur every summer in various parts of the city. Besides the losses and inconvenience felt by the residents, floods produce damages that cross the city boundaries, affecting income and output in the metropolitan area as well as in other parts of the state and the country. The objective of this study is to evaluate the economic impacts of floods in the city of São Paulo through the use of a Spatial Computable General Equilibrium (SCGE) model integrated to GIS information related to the location of points of floods and the firms within their influence. It is estimated that floods contributed to reduce city growth and residents' welfare, as well as hampering local competitiveness in both domestic and international markets. An intra-city total impact-damage ratio of 2.2 and an economywide total impact-damage ratio of 5.0 were found.

The verticalization of cities impacts the quality of urban life. The empirical investigation of the determinants of the floor-area ratio (FAR) of lots using the traditional econometric approaches, however, has little explanatory power, and research about it using machine learning (ML) is almost nonexistent. This study applies two ensemble machine learning strategies, random forest (RF) and extreme gradient boosting (XGBoost), to investigate the determinants of the FAR of all formally registered multifamily residential lots in the city of Recife, Brazil. Taking into account a collection of key determinants influencing the floor area ratio (FAR), which encompass structural, accessibility, environmental, amenity, and policy variables, the findings reveal that the ensemble random forest approach significantly enhances the explanatory ability of these determinants when compared to conventional strategies like ordinary least squares (OLS) or locally weighted regression (LWR). Although generally in line with traditional urban economic arguments, the evidence also reveals important non-linearities in the effects of the variables on the FAR that are useful for urban planning and public housing policy.