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Le climat est un élément important de la vie des territoires car il conditionne le comportement et les décisions des individus et des groupes sociaux comme celui de l’ensemble des espèces vivantes et des écosystèmes. A ce titre, la différenciation de l’espace selon les climats et les aptitudes qui en résultent est un domaine qui mérite d’être réinvesti par la recherche en mettant à profit des moyens de traitement modernes de l’information. Avec cet objectif en vue, les auteurs proposent une approche spatiale de définition des climats. Partant des mesures stationnelles de précipitation et de température mises à disposition par Météo-France, un jeu de 14 variables intégrant une série temporelle de 30 ans (1971-2000) est défini pour caractériser les climats et leurs modalités distinctives de variation. Une méthode originale dite d’interpolation locale permet de reconstituer les champs spatiaux continus des variables en question et de les exprimer sous forme de couches d’information gérables par SIG. Ces données sont ensuite soumises à un traitement associant analyse factorielle des correspondances et classification hiérarchique ascendante pour en obtenir une typologie où huit climats sont identifiés et cartographiés sur le territoire métropolitain. Un traitement complémentaire faisant appel aux probabilités permet de restituer l’espace de distribution potentielle de chacun des types et de nuancer la partition stricte tirée de la classification. Une synthèse met en perspective les résultats obtenus pour les réinterpréter dans un schéma général de compréhension du climat. Deux annexes permettent de télécharger les bases cartographiques et les données associées à cet article.

Les systèmes socio naturels possèdent la capacité de résister aux aléas. Les catastrophes les perturbent, mais les font rarement disparaître. Le concept de résilience, d’origine physique, qui illustre cette capacité s’est enrichi lors de son transfert dans différentes disciplines scientifiques. Certes, la résilience est difficile à mesurer. Mais sa connaissance permet d’adopter de nouvelles formes de gestion des risques naturels ou sociaux. Ces nouvelles formes de gestion sont très différentes des approches technologiques qui ne sont pas toujours bien adaptées au milieu ou à la société.

Cholera outbreaks have occurred in Burundi, Rwanda, Democratic Republic of Congo, Tanzania, Uganda, and Kenya almost every year since 1977-1978, when the disease emerged in these countries. We used a multiscale, geographic information system-based approach to assess the link between cholera outbreaks, climate, and environmental variables. We performed time-series analyses and field investigations in the main affected areas. Results showed that cholera greatly increased during El Nino warm events (abnormally warm El Ninos) but decreased or remained stable between these events. Most epidemics occurred in a few hotspots in lakeside areas, where the weekly incidence of cholera varied by season, rainfall, fluctuations of plankton, and fishing activities. During lull periods, persistence of cholera was explained by outbreak dynamics, which suggested a metapopulation pattern, and by endemic foci around the lakes. These links between cholera outbreaks, climate, and lake environments need additional, multidisciplinary study.

Urban patterns show often an irregular morphology. The fact that this phenomenon appears often despite of the intensions of planers and that it is not related to a particular historical situation, incites to suppose the existence of self-organisation process, promoting such an evolution. To get more insight in these aspects of urban growth, it has been investigated, whether there exists appropriated quantitative measures to characterize the irregular structures. The analysis of the build-up area of a certain number of agglomerations of the scale of metropolitan areas has shown, that the urban patterns follow an interior order principle, and that they may be characterized by fractal dimensions. Thus the spatial organization of agglomerations follows a hierarchization principle, which appears on the scale of metropolitan areas as a radial dilution of the build-up area, according to a pareto-distribution. The fact that urban patterns follow such an order principle allowed to give an interpretation, based on sociological theories, of the socio-economic interactions giving rise to such an irregular growth. For some of these interactions it has been shown by use of a simulation model that these effects give really rise to a fractal urban pattern. The fractal analysis has been used too, to investigate the spatial organization of transportation networks. For town quarters, this method describes the hierarchical organization of the street pattern, and for metropolitan areas the accessibility, assured by the network, is measured.

BACKGROUND: During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. METHODOLOGY/PRINCIPAL FINDINGS: In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants) and South Kivu (4,670,121 inhabitants) from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9). Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. CONCLUSION/SIGNIFICANCE: Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.

Recently, fractal theory has become popular in urban geography. Actually, its formalisation is compatible with many characteristics of the urban systems: self-similarity in clustering and fragmentation of spatial patterns at different scales, hierarchical organisation, sinuosity of borders, and non-linear dynamics. First, we recall how fractal properties can be related to important features of urban morphology just as easily as to the evolution of urban systems. Second, we briefly review the main trends in the application of fractals to urban issues: the description of urban morphologies (built-up areas, distribution of activities, networks, borders…), the simulation of urban growth and settlement systems analysis. A specific application to the question of urban limits will be presented in detail. Issues of relevance and validation will be discussed, especially regarding the combination of different types of spatial structures.

Landscape graphs are increasingly used in ecology, conservation, and landscape planning for modeling habitat connectivity of wildlife species. We present here the follow-up of Graphab, a software application for modeling habitat networks. This application has been recently enhanced by advanced functions of spatial analysis, command-line facilities, and connections with other software applications. It has been used in many studies, first in ecological studies for analyzing the role of landscape connectivity on biological responses measured in the field, second for supporting decisions concerning biodiversity preservation. Future improvements could be made to make the links more realistic with respect to ecological processes.

Abstract Pollinators play a crucial role in ecosystems globally, ensuring the seed production of most flowering plants. They are threatened by global changes and knowledge of their distribution at the national and continental levels is needed to implement efficient conservation actions, but this knowledge is still fragmented and/or difficult to access. As a step forward, we provide an updated list of around 3000 European bee and hoverfly species, reflecting their current distributional status at the national level (in the form of present, absent, regionally extinct, possibly extinct or non‐native). This work was attainable by incorporating both published and unpublished data, as well as knowledge from a large set of taxonomists and ecologists in both groups. After providing the first National species lists for bees and hoverflies for many countries, we examine the current distributional patterns of these species and designate the countries with highest levels of species richness. We also show that many species are recorded in a single European country, highlighting the importance of articulating European and national conservation strategies. Finally, we discuss how the data provided here can be combined with future trait and Red List data to implement research that will further advance pollinator conservation.

Abstract In landscape genetics, habitat connectivity and population genetic structure have been analysed using graph‐theoretic approaches to understand how landscape features influence demography (i.e. dispersal and population size). Despite substantial advances in enhancing both genetic and landscape graph use, a software tool bringing together a large range of construction and analysis parameters for these two types of graphs was lacking in the landscape genetic toolbox. Moreover, although these two types of graphs appear complementary for answering landscape genetic questions, methods for comparing them have not been forthcoming. We have developed an R package to improve and encourage the use of these graphs. It includes functions for converting and importing genetic data and for genetic distance computing. It also implements time‐efficient geodesic and cost‐distance calculations from spatial data. A large range of parameters can be used to create genetic and landscape graphs from these data, including several graph pruning methods. We made available to R users the command‐line facilitaties of Graphab software to easily model landscape graphs in R. The package functions perform preliminary analysis to adapt methodological choices to research questions. Landscape and genetic graphs created can be analysed with node‐level metrics as well as link‐level and modularity analyses. Users can compare and visualise these graphs and export them to shapefiles to facilitate interpretation and subsequent analyses. graph4lg contributes to expanding landscape and genetic graph potential for analysing ecological connectivity while encouraging further investigations on methodological implications related to these tools.

BACKGROUND: To date, few epidemiologic studies have examined the relationship between environmental PCDD/F exposure and breast cancer in human populations. Dioxin emissions from municipal solid waste incinerators (MSWIs) are one of the major sources of environmental dioxins and are therefore an exposure source of public concern. The purpose of this study was to examine the association between dioxins emitted from a polluting MSWI and invasive breast cancer risk among women residing in the area under direct influence of the facility. METHODS: We compared 434 incident cases of invasive breast cancer diagnosed between 1996 and 2002, and 2170 controls randomly selected from the 1999 population census. A validated dispersion model was used as a proxy for dioxin exposure, yielding four exposure categories. The latter were linked to individual places of residence, using Geographic Information System technology. RESULTS: The age distribution at diagnosis for all cases combined showed a bimodal pattern with incidence peaks near 50 and 70 years old. This prompted us to run models separately for women aged 20-59 years, and women aged 60 years or older. Among women younger than 60 years old, no increased or decreased risk was found for any dioxin exposure category. Conversely, women over 60 years old living in the highest exposed zone were 0.31 time less likely (95% confidence interval, 0.08-0.89) to develop invasive breast cancer. CONCLUSION: Before speculating that this decreased risk reflects a dioxin anti-estrogenic activity with greater effect on late-onset acquired breast cancer, some residual confounding must be envisaged.

Abstract Future warming in the Mediterranean is expected to significantly exceed global values with unpredictable implications on the sea-level rise rates in the coming decades. Here, we apply an empirical-Bayesian spatio-temporal statistical model to a dataset of 401 sea-level index points from the central and western Mediterranean and reconstruct rates of sea-level change for the past 10,000 years. We demonstrate that the mean rates of Mediterranean industrial-era sea-level rise have been significantly faster than any other period since ~4000 years ago. We further highlight a previously unrecognized variability in Mediterranean sea-level change rates. In the Common Era, this variability correlates with the occurrence of major regional-scale cooling/warming episodes. Our data show a sea-level stabilization during the Late Antique Little Ice Age cold event, which interrupted a general rising trend of ~0.45 mm a −1 that characterized the warming episodes of the Common Era. By contrast, the Little Ice Age cold event had only minor regional effects on Mediterranean sea-level change rates.

Ongoing global change and its direct environmental impacts, in addition to securing economic transition to the post-oil era, could trigger complex socio-economic and political crises in oil-dependent economies of the Persian Gulf Region (PGR). To evaluate the role of climate change and related policies in degrading the environment and its socio-economic impacts in the PGR, we have used a variety of available global datasets and published data. The results show that the countries of the PGR pursue some types of socio-economic reforms to alleviate the impacts of climate change. However, it seems that these attempts are not compatible with the environment's capacity. The main problem stems from the fact that political differences between the PGR nations prevent them from managing the Persian Gulf environment as an integrated natural system and consequently they have to limit their efforts within their borders, regardless of what happens in other parts of the system. The shift to alternative revenue sources by the countries needs socioeconomic preparedness while there are environmental obstacles, political tensions and geopolitical rivalries. Unless there is a cooperative approach to mitigate the effects of climate change, accompanied by a reorientation of PGR economies, the situation is likely to worsen rather than improve. To address the challenges of climate change, integrated regional collaborations are needed. Collective action, such as more investment in regional research and development and education, is required if the PGR is to successfully transition from a commodity-based to a knowledge-based economy.

Urban growth generates nowadays patterns, which look rather irregular. Planning policy regrets the lack of compactness and density of these agglomerations, but controlling urban sprawl turns out to be difficult. Obviously a new type of spatial organisation emerges, which is rather the result of a self-organisation process to which a high number of social agents contribute. In the present contribution we focus on the use of fractal geometry which turned out to be a powerful instrument for describing the morphology of these patterns.After an introduction about the context of research, fractal models are presented, which serve as reference models for better understanding the spatial organisation of settlement patterns. Then the methodology for measuring their morphology by means of fractal parameters is explained. Moreover different peculiar topics are considered like a specific approach of urban boundaries. Then an overview is given over results obtained for a couple of agglomerations in different European countries. The interpretation of these results allows establishing links between urban planning policy and pattern morphology. Applying the idea of self-organisation leads to introducing a fractal order parameter for studying the emergent fractal order in urban patterns. The presentation of these quantitative results will be completed by some reflections about how planning concepts based on fractal geometry may help to manage more efficiently urban sprawl.

Challéat, S., K. Barré, A. Laforge, D. Lapostolle, M. Franchomme, C. Sirami, I. Le Viol, J. Milian, and C. Kerbiriou. 2021. Grasping darkness: the dark ecological network as a social-ecological framework to limit the impacts of light pollution on biodiversity. Ecology and Society 26(1):15. https://doi.org/10.5751/ES-12156-260115

Abstract The history of the Eastern Mediterranean is punctuated by major crises that have influenced many of the region's established socioeconomic models. Recent studies have underscored the role of drought and temperature oscillations in driving changes but attempts to quantify their magnitude remain equivocal, hindering long‐term assessments of the potential interplay between climate and society. Here, we fill this knowledge gap using a 6,000‐year pollen‐based reconstruction of temperature and precipitation from Hala Sultan Tekke, Cyprus. We find that major social changes and plague outbreaks often occurred in tandem with cooler climate conditions, with anomalies ranging from −3 ± 0.4 °C to −1 ± 0.5 °C, coupled with changing precipitation patterns. We suggest that major climate changes may weaken societies by affecting primary livelihood systems. This long‐term view highlights recurrent cold periods in the Eastern Mediterranean's climate history and advocates that, despite frequent adversity and pandemics, Near Eastern populations adapted and were ultimately resilient to major climate changes.

Abstract Artificial light at night (ALAN) is considered as a major threat to biodiversity, especially to nocturnal species, as it reduces availability, quality and functionality of habitats. However, its effects on the way species use landscape elements such as rivers are still largely understudied, especially the effect of crossing infrastructure lighting on bridges. These elements are nevertheless key commuting and foraging habitats in heavily urbanised landscapes for several taxa such as bats that are particularly affected by ALAN. We studied the effects of the illumination of facades and undersides of bridges on the relative abundance of pipistrelle bats, on their 3D distribution and their behavioural response (i.e. flight speed) close to bridges. We set‐up an innovative approach based on a microphone‐array to reconstruct positions and flight trajectories in 3D. We studied the effect of lighting on bats in the close proximity of six similar bridges, mostly differentiated by the presence or absence of lighting (3 lit and 3 unlit). All bridges cross the same waterway, within a uniformly and highly urbanized agglomeration (Toulouse, France). We found that bat activity was 1.7 times lower in lit sites. Bats tended to keep a larger distance, and to fly faster close to illuminated bridges. These results suggest that bridge lighting strongly reduces habitat availability and likely connectivity for bats. In that case, results call for switching off the illumination of such bridges crossing riverine ecosystems to preserve their functionality as habitats and corridors for bats.

Identifying urban boundaries involves analysing both the functional and the morphological aspects of urban systems. In this paper, we adopt a purely morphological approach and compare three methods for the morphological delineation of cities. Each method avoids using any predefined quantified threshold (size, distance, built density, etc.) to detect crucial discontinuities in space. The first method identifies Natural Cities by clustering points. The other two are the fractal-based MorphoLim method and the Hierarchical Percolation; both involve transforming the data using a step-by-step dilation process. The three methods are critically compared and illustrated by applications to theoretical urban patterns. We further apply each method to the urban agglomeration of Brussels, the Belgian capital, using different data (building footprints, building centroids and street nodes) and considering two study areas, namely the former province of Brabant and the entire country of Belgium. The results show that it is impossible to draw an unambiguous morphological boundary for an urban agglomeration. Consequently, it is crucial to relate the data used, the size of the study area and the method chosen to the objectives of the delineation.

Abstract One of the most devastating environmental consequences of war is the disruption of peacetime human–microbe relationships, leading to outbreaks of infectious diseases. Indirectly, conflicts also have severe health consequences due to population displacements, with a heightened risk of disease transmission. While previous research suggests that conflicts may have accentuated historical epidemics, this relationship has never been quantified. Here, we use annually resolved data to probe the link between climate, human behavior (i.e. conflicts), and the spread of plague epidemics in pre-industrial Europe (AD 1347–1840). We find that AD 1450–1670 was a particularly violent period of Europe’s history, characterized by a mean twofold increase in conflicts. This period was concurrent with steep upsurges in plague outbreaks. Cooler climate conditions during the Little Ice Age further weakened afflicted groups, making European populations less resistant to pathogens, through malnutrition and deteriorating living/sanitary conditions. Our analysis demonstrates that warfare provided a backdrop for significant microbial opportunity in pre-industrial Europe.

We are confronted with rising energy consumption inter alia due to increasing worldwide mobility contributing to the greenhouse effect and global warming. Thus, one of the challenges in planning is to manage urban sprawl by introducing an efficient distribution of agglomerations and an optimal urban pattern incorporating economic, ecological, and social expectations of sustainable regional and urban development. In order to tackle these challenges we have taken a specific interest in the benefits of using a multifractal logic combined with measures of accessibility to urban and rural amenities including temporal settings for planning. Herein, we propose a multiscale, multifractal simulation model named Fractalopolis for simulating and evaluating scenarios consistently from a regional to a neighbourhood scale. Access to shops, services, and facilities can be improved by altering the location, whereas access to natural areas and urban green spaces can be improved by suggesting different areas for urbanization. The urbanization strategy will impact on the future regional layout and urban form. The computer application supports GIS data for incorporating the simulation system into planning support systems to support planning processes and assist with choice processes.