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African cities remain little known. As a result, they are outside the global intellectual arena on urban issues, which justifies the need for more productive research. This article aims to empirica...

Context Urbanization is the most important form of landscape change and is increasingly affecting biodiversity and ecosystem functions. Understanding how landscape patterns change in space and time is central to the evaluation of the environmental impacts of urbanization. Objectives This research explores the spatiotemporal patterns of land use change in the Swiss urban agglomerations of Bern, Lausanne and Zurich at two characteristic spatial extents, and compares them to prominent hypotheses of urbanization patterns. Methods For each urban agglomeration, four temporal snapshots from 1980 to 2016 have been derived from the land use inventory of the Swiss Federal Statistical Office. Fractal analysis of the area-radius relationship of urban land is used to separate each agglomeration into two characteristic spatial extents according to the distance of the city center, namely the inner and outer zones. The landscape metrics and growth modes are then computed at such extents. Results The time series of landscape metrics and growth modes reveal fairly different patterns when computed in the inner and outer zones respectively. Bern and Lausanne exhibit mostly traits of coalescence stages at the inner zone while displaying many characteristics of diffusion in the outer zone. In contrast, the trends of observed in the inner and outer zones of Zurich are both reminiscent of a coalescence stages. Conclusions Fractal analysis can be a useful approach to detect characteristic extents of urban agglomerations at which distinct spatiotemporal patterns might be observed. Current models of urbanization patterns should incorporate the notion of characteristic extents more explicitly.

Despite the importance of understanding the historical dynamics of ecosystem services (ES), littleresearch has focused on a historical, spatially explicit, assessment of ES supply. This research is aimed at understanding the spatial patterns and potential drivers of temporal variations of ES supply. It has assessed associations of ES temporal variations, delineated ES bundles from changes in ES supply over time, and identified potential drivers of ES bundles. Finally, we discuss the potential implications for spatial planning. We reconstructed the spatio-temporal pat-terns of 11 ES supply in the canton of Vaud, Switzerland, between 1979 and 2014. We used Spearman’s rank coefficient, k-means clustering and redundancy analysis to understand the spatial patterns and potential drivers of temporal variations of ES supply. Municipalities were grouped into four clusters based on ES supply changes over four decades. Food production showed the most negative associations with other ES. Regulating ES were not always synergetic and were less related to increases in population density than cultural ES, which were found in low population density municipalities. In general, synergetic ES may not respond to the same potential drivers. Municipalities were able to supply ES at different levels but none showed an increase in all ES. ES can be synergetic in one bundle, but antagonistic in another. Different processes can cause a change in the same ES depending on their supply location. It seems unrealistic to require each municipality to have a multifunctional territory in the current political context.

Ecosystem services (ES) are dynamic over space and time. Understanding and quantifying spatio-temporal trade-offs and synergies among multiples ES, as well identifying the drivers of change provides an opportunity to make the link between ecosystems, policy and land management. We present an approach to understand the historical dynamics of ES and to analyze the regional diversity in ES changes in Switzerland. A spatio-temporal approach was used to examine changes of nine ES and their relationships from 1986 to 2015 across the twenty-six Swiss cantons. We found that ES supply was dependent on the spatial and temporal distribution of interacting factors. The relationships between ES shifted through time, and the correlation between the supply of ES and the distance between cantons was significant but remained almost constant through time. Each canton is providing a specific bundle (a set of positively correlated ES), dominated by just a few services. Trajectories in ES supply were related to changes in population density and the surface area of organic farming, reflecting trajectories in national strategies of land use planning and agriculture, respectively. Cantons with the lowest supply of ES had the highest population density, while the cantons with the greatest abundance of cultural ES had the lowest population density, which suggests that the densification trend in Switzerland could yield negative externalities. The promotion of organic farming and moderate population density was suitable to ensure sustainable supply of provisioning and regulating ES, but not cultural ES. We provide clear evidence of the dynamic nature of ES through time. Analyses of the relationships between the drivers and ES supply allows identifying the potential limits of national policies and new forms of land use planning based the ecosystem multifunctionality of territories.

Previous studies assessed cultural ecosystem services (CES) at the local scale but often ignored them in national assessments. This paper explores CES relationships in Switzerland using web-based participatory mapping. We identified the spatial relationships between CES, the drivers of negative change and solutions to mitigate it. Results indicated that CES tend to have positive spatial relationships, although not always significant. A proxy-based approach supported the findings that the provision of heritage and inspiration services decreased along the urban–rural gradient while others increased. Participants located more CES close to their residence, but acknowledged their presence in distant alpine regions. They reported that better planning and stricter implementation of policies were necessary to refrain CES loss. According to respondents, there might be a density threshold to ensure sustainable supply of CES. Although mitigation measures were specific enough at the national scale, they remained too broad to be applicable at the local scale.

Materials to reproduce the results of the paper "Evaluating urban greening scenarios for urban heat mitigation: a spatially-explicit approach". Detailed instructions of the steps to reproduce the results can be found in the `README.md` of github.com/martibosch/lausanne-greening-scenarios. Citation Bosch, M., Locatelli, M., Hamel, P., Jaligot, R., Chenal, J., and Joost, S. 2020. "Evaluating urban greening scenarios for urban heat mitigation: a spatially-explicit approach". Preprint available atbioRxiv.10.1101/2020.11.09.373779 If using any of the following files, the sources must be acknowledged accordingly: `invest-calibrated-params.json`: based on the calibration by Bosch et al. [1]. `ref-et.tif`: obtained using the minimum, average and maximum temperature datasets of the copyrighted Spatial Climate Analyses of MeteoSwiss [2]. `station-t.csv`: the temperature observations correspond to monitoring stations operated by Agrometeo, the Federal roads office (ASTRA), the Federal office for the environment (BAFU), the General directorate for the environment of the Canton of Vaud (DGE), and the Federal Institute of Forest, Snow and Landscape Research (WSL) [3]. See the file `station-locations.csv` for more details. Acknowledgments With the support of the École Polytechnique Fédérale de Lausanne (EPFL) References Bosch, M., Locatelli, M., Hamel, P., Remme, R. P., Chenal, J., and Joost, S. 2020. "A spatially-explicit approach to simulate urban heat islands in complex urban landscapes". Under review in Geoscientific Model Development. 10.5194/gmd-2020-174 Frei, C., 2014. Interpolation of temperature in a mountainous region using nonlinear profiles and non‐Euclidean distances. International Journal of Climatology, 34(5), pp.1585-1605. 10.1002/joc.3786 Rebetez, M., von Arx, G., Gessler, A., Pannatier, E.G., Innes, J.L., Jakob, P., Jetel, M., Kube, M., Nötzli, M., Schaub, M. and Schmitt, M., 2018. Meteorological data series from Swiss long-term forest ecosystem research plots since 1997. Annals of Forest Science, 75(2), p.41. 10.1007/s13595-018-0709-7

In Africa, cities are unable to accommodate population growth within their current administrative limits, putting pressure on ecosystem services (ES) in peripheral areas. Existing ES related studies in the region were conducted in East and South Africa, and rarely focused on cultural ES in peri-urban areas. This study aimed to assess changes in the value of cultural ES in two peripheral areas of Yaounde, Cameroun. It applied the concept of ES through participatory geographic information systems (PGIS) to understand how the value of cultural ES has changed over time and how residents perceive it. It also considered the impact of land management by relating changes in ecosystem service provisioning areas (SPA), with the current land tenure system. We focused on two study areas, Mbalngong and Nkozoa, which were selected for their high urbanization rates. PGIS activities were conducted during twenty semi-directive interviews and one workshop per site. We found that the provision of ES decreased by more than 90% within an 18-year period, from 2000 to 2018. The lack of randomness in the distribution of ecosystem services showed that SPA had distinct functions for residents, but that this was not taken into consideration in planning decisions. We showed that current land management strategies are influenced by the land tenure system and do not incite landowners to preserve their parcels and associated SPA. While direct subsidies may not be appropriate, other approaches such as community land trusts may be more advisable for the preservation of SPA.

Switzerland is one of the largest producers of municipal solid waste (MSW) per capita. The principle of decoupling attempts to evaluate the relationship between consumption and production, and to measure the relationship between an activity and its impact on the environment. This paper uses the Environmental Kuznets Curve (EKC) hypothesis to understand the impact of three socio-economic drivers on MSW generation in the canton of Vaud in Switzerland. Vaud is a French-speaking canton that recently implemented several measures to limit MSW generation. We used time series of indicators for income, urbanisation and policy implementation in ten of the canton’s districts, which were set as independent variables, between 1996 and 2015. A panel data analysis was performed using a generalized least squares procedure to test for an EKC. Evidence shows that urbanization was slightly negatively associated with MSW generation, but without statistical significance. However, a direct policy mechanism such as the waste bag tax was significantly correlated with a decrease in waste generation. Overall, the presence of an EKC cannot be confirmed in the canton of Vaud, as waste generation tends to stabilize as income increases. It would be useful to perform a similar assessment in other cantons to fully inform decision-makers.

A methodology has been developed to apply value chain analysis (VCA) to the informal recycling sector, and demonstrated using the Zabaleen in Cairo, Egypt as a case study. The VCA methodology provides a ⿿toolkit⿿ comprising four stages. The first involves mapping the value chain and has been demonstrated using the recycling of polyethylene terephthalate (PET) bottles as the particular example. Stage 2 tabulates the value added at each step in the value chain; this has been demonstrated for different types of plastics as well as other recycled fractions. Stage 3 identifies and then applies a set of indicators for the development of the informal sector recycling value chain in order to address technical and socio-economic challenges. The indicators proposed are in three categories: connections in the value chain, waste valorisation and the enabling environment. Stage 4 involves developing a system dynamic map that shows connections between the indicators, and the stocks and flow variables in the value chain. In particular, it identifies the most highly connected indicators on which to focus interventions, as these are likely to have the greatest impact on the overall system. For the Zabaleen, these are improving the quality of waste inputs into the value chain through source segregation, optimising access to waste and upgrading recycling activities through access to finance and technical knowledge.

We report a novel method for the spatial analysis of informal transport activities for future environmental planning. It uses a combination of spatial data gathered with GPS devices and semi-formal interviews. We show that the current configuration of the system is not optimized. It leads to a greater concentration of motorcycle taxis activities in denser urban areas, emitting high levels of noise and air pollution. Recommendations include decentralizing part of the activity and closer monitoring of the number of pilots

Integrating the concept of ecosystem services (ES) into spatial planning is an opportunity to make land use and management choices that maximize the delivery of multiple ES. The assessment of social demand can be useful for the identification of priority areas or potential conflicts among stakeholders. We used Q-methodology to understand stakeholder perspectives on ES to facilitate their integration into spatial planning in the canton of Vaud, Switzerland. Three perspectives, utilitarian, cultural and protective, were analyzed and used to discuss potential implications for spatial planning. First, ecosystem multifunctionality and synergies among ES should be emphasized. Second, the food production system should move away from a productive-only approach, to a system that protects soils and their functions. Providing a paradigm change, arable land could be protected to the same level as forests and farmers could be incentivized further to change their practices. Finally, our findings show a potential over-interpretation of the importance of cultural ES in current planning policies, as most participants would be ready to change their behaviors to preserve biological functions. It would be useful to conduct a similar study in other cantons to ensure that the results are fully representative of the current situation in Switzerland.

The emergence of motorcycle taxis as a mode of urban transport in Africa can be seen as a bottom-up response to the larger problem of a demand that is not sufficiently met by public services. Transcending the debates regarding the relevance of this solution, this article explores motorcycle taxis as substitute for urban transport in Yaounde, Cameroon. The study aims to improve the understanding of how drivers run their activity and to identify its impacts on the city using a mixed-methods approach. We combined the data from a three-week GPS motorcycle taxis route survey with semi-structured interviews, questionnaires and direct observation. This approach, which in itself is innovative for the study of informal transport in Africa, is an important methodological contribution. The analysis of the data collected highlights small radii of action and high inactivity rates, and helps shed light on how this mode has led to an increased demand for short trips in more diffuse urban forms. We point to the need for holistic thinking in order to better integrate motorcycle taxis into urban transportation planning policies in Yaounde as well as other major cities in the region.

The concept of ecosystem services (ES) is regarded as an increasingly important framework and tool to support spatial planning. A limited understanding of how ES knowledge is used in spatial plans constrains our ability to learn from, replicate, and convey an ES approach. This study examined how ES were integrated into spatial planning at the regional scale in Western Switzerland. A directed content analysis of cantonal structural plans was used to assess how ES were covered in various sections of the plans and to explore the differences in the level of ES integration across cantons. First, the results showed that ES were found in each section of the plans but were not equally distributed. Provisioning ES were always the most mentioned while regulating ES were the least considered. Second, strong discrepancies existed between cantons may demonstrate the lack of cantonal coordination to integrate ES. Finally, the concept of ES was more embedded in nonbinding than in binding parts. Promoting the concept at the national level may facilitate the integration of ES at lower planning scales. Further work could focus on other cantons to ensure that the results are fully representative of the current situation in Switzerland.

Modern cities dynamically face several challenges including digitalization, sustainability, resilience and economic development. Urban planners and designers must develop urban forms that address these challenges. With the integration of new communication and information technologies (Smartphone, GIS, Drones, IoT, Sensors, etc.), urban activities have generated large volumes of urban data. The rapid growth in terms of collection and big data storage capacities combined with the ever-increasing computational power of modern machines have made possible their efficient treatment using machine (ML) and deep learning (DL) algorithms. The emergence of such groundbreaking methods has in turn helped to address the challenges of modern-day cities in several domains (health, security, mobility, etc). ML algorithms have been proposed to model the urban form’s indicators for intelligent urban planning decision making. They have been proven to perform better than the traditional methods. However, the potential of ML has not yet been fully explored in research for urban planning decision support. This paper presents a comprehensive review of ML applications for mitigating the challenges of modern cities planning. First and foremost, an overview of the urban forms, sources of urban data, the ML and DL techniques as well as their potential in solving the aforementioned challenges. For each ML method, we will highlight it working principle, advantages, disadvantages and potential applications using comparative tables. Finally, we will discuss the issues and challenges of ML methods in urban form’s modeling while ultimately advocating some future research directions.