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The variability of urban growth in the Mexico City conurbation reflects the complexity of changes and uncertainty experienced in many urban areas. The goal of this project is to identify how the urban expansion of the Mexico City conurbation reflects the changes in socioeconomic variables of the region over recent decades. The authors first spatially quantified the rate of urban growth from 1990 to 2020 using Landsat data and then identified the socioeconomic variables associated with this urban expansion. Results showed a progressive loss in vegetated land and an increase in urban land. The population's access to roads and the marginalization index had the highest positive correlation with the observed urban growth. Although these variables were highly correlated with each other, access to roads was not found to be a variable of importance for projecting urban growth. Finally, two distinct zones of urban growth were determined using cluster statistics; the first showed no growth, which corresponded with more established, older municipalities closer to the city centre, and the second zone had significant growth, which corresponded to municipalities away from the centre, coinciding with urban decentralization and new lifestyle patterns. The identification of urban growth zones and socioeconomic variables associated with that growth will assist with effective planning, infrastructure development, and resource management. [ABSTRACT FROM AUTHOR]

The divergence that exists between urban planning standards, land acquisition practices and land tenure practices governs land use in the Cameroonian capital. The present research which the objective is to analyse the socio-spatial logics that lead to the increasing settlement of the populations in these so-called 'non aedificandi' spaces, is based on the hypothesis that the land practices around these mountains are characterized by a precariousness which increases the level of vulnerability of the populations living there. The research is based on a hypothetico-deductive method coupled with documentary research, semi-directive interviews, direct observations and surveys of 100 households in the Akok-Ndoué and Mbankolo neighbourhoods. It emerges that population dynamics around these mountains are fuelled by migratory movements and land saturation in urban areas, which has led to a rush of people towards the mountains, particularly in high-risk areas. In these mountains, the population finds an adequate occasion to develop several types of land tenure practices, and customary land appropriation is common. These populations are often aware that they are accessing land and housing illegally and marginally. Almost unaware of the risks involved, they usually obstinate to acquire and exploit those mountains. However, the populations in these areas qualified as non aedificandi, are exposed to landslides, collapse and floods risks. Unfortunately, ignorance and socio-economic conditions influence their perception of the risks to which they are exposed. It therefore result in an increase in their level of vulnerability which is materialized by illegal occupations and very precarious land rights. [ABSTRACT FROM AUTHOR]

The municipality of Gagnoa (Central West Ivorian region) came into being as a result of the colonial power’s desire to set up an outpost on the continent, to secure a cost-effective harnessing of the hinterland’s natural economic resources. The town’s economic background made it possible for the then authorities to capitalize on the exploitation of the forestry and agricultural resources that are located in its hinterland. However, the planting-intensive economy also brought a large inflow of people into the town, which in turn had an impact on its progress. Gagnoa’s urban areas increased from 280 hectares in 1952 to 5,400 hectares in 2017, while its population rose from 2,000 in 1948 to 175,000 in 2017 (general population census dated 2014). In the light of the requirements of urban dynamics, social public facilities turned out to be inadequate. In several neighbourhoods, the town lacks drinking water. Households resort to various supply strategies, such as digging wells in the backyards or storing water in tanks. While public lighting remains unsatisfactory in several areas of the town, new urban areas are not serviced at all. As a result, unauthorised housing developments and property speculation are on the rise, all of which expose urban dwellers to hardship. Against this backdrop, human security, as a pursuit of social well-being and high standard of living, is far from being a reality in this very town. [ABSTRACT FROM AUTHOR]

A Dakar, les zones humides constituent des espaces naturels, abritant une part essentielle de la biodiversité urbaine. Elles sont un patrimoine naturel à préserver (Lézy-Bruno, 2010). Bien que leur utilité soit reconnue par tous (Aschan-Leygonie, Bonnaud et Girault, 2015, Beaumais et al., 2008), leur maintien se heurte aux envies d'occuper plus d'espace. La conservation des zones humides au cœur de la ville pose de plus en plus de problèmes, inhérents aux dynamiques urbaines. Actuellement, les zones humides apparaissent comme une contrainte à l'urbanisation dans certains quartiers de Dakar. Elles disparaissent au profit des habitations et des infrastructures publiques. Paradoxalement, les zones humides polarisent diverses activités socio-économiques (agriculture, pêche, élevage, etc.) dans la ville. De ce fait, elles font l'objet de conflit entre plusieurs acteurs (autorités étatiques, populations, organisations de protection de l'environnement). Mais, au-delà des conflits, il s'agit d'une opposition entre deux appréhensions de l'usage des paysages naturels urbains. Si la nécessité de mettre en valeur ces espaces naturels est évidente pour certains acteurs, d'autres pensent par contre qu'ils doivent être requalifiés ou réaffectés à des vocations résidentielles et des activités connexes.

The general objective of this paper is to discuss strong spatial discontinuities in Asian megacities and their potential effects, notably in terms of population health. The factors for exposure to risks vary in the life of individuals, whether it is over a long period of residential migrations or a short one of daily mobility. In the context of dengue epidemics, it is this second modality of urban mobility that interests us as it helps to differentiate exposure to the virus among individuals, beyond those related to their places of residence. This reflection relies on exploration of original datasets designed to better characterize the structures and dynamics in cities where the researcher did not have access to spatialized data until recently. The spread of Internet, smartphones and applications open to geo-localization, has helped to create new opportunities for collecting data. In this paper, we propose to explore POI (Point of Interest) data from Google and the Twitter social network to develop a typology of activities of the city of Bangkok and to measure its tempo/pulsations more appropriately through daily mobilities. [ABSTRACT FROM AUTHOR]

The mobility system of a territory is understood as an important technical foundation that is incorporated into the territory by giving it material and organizational qualities. Such a system is characterized by the integration between fixtures (engineering systems) and flows (circulation/mobility systems); those (the former) serving for the development of these (the latter), outlining the movement of goods, people and capital. With this theoretical perspective, in this article our aim is to understand the importance of the Natal-Caico highway axis within the mobility system of Rio Grande do Norte. Of the highways that make up the macro-structure of the Potiguar territory, the Natal-Caico axis stands out due to interconnecting municipalities in the countryside and along the state's coast. It stands out for its intermunicipal flow of passengers and is characterized by cities whose economic center is the highway that runs through them. Thus, we have conducted theoretical reflections and primary statistical data analysis with the aim of understanding the territorial fluidity and the urban dynamics of this highway axis in question. This understanding leads us to the final consideration that the Natal-Caico highway axis is a subsystem of mobility in the Potiguar territory whose urban economy is segmented into two matters: the use of the territory as a resource to be exploited, as evidenced by the activities of the upper circuit of the urban economy; and use of the territory as a shelter for the survival of the poor, triggered by the activities in the lower circuit. [ABSTRACT FROM AUTHOR]

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Abstract: The paper provides a mathematical study of a model of urban dynamics, adjusting to an ecological model proposed by Lotka and Volterra. The model is a system of two first-order non-linear ordinary differential equations. The study proposed here completes the original proof by using the main tools such as a Lyapunov function. To cite this article: J. El Ghordaf et al., C. R. Biologies 327 (2004). [Copyright &y& Elsevier]