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Glacier forelands provide an excellent opportunity to investigate vegetation succession and soil development along the chronosequence; however, there are few studies on soil biogeochemical changes from environmental factors, aside from time. This study aimed to investigate soil development and biogeochemical changes in the glacier foreland of Midtre Lov ́enbreen, Svalbard, by considering various factors, including time. Eighteen vegetation and soil variables were measured at 38 different sampling sites of varying soil age, depth, and glacio- fluvial activity. Soil organic matter (SOM) was quantitatively measured, and the compositional changes in SOM were determined following size-density fractionation. In the topsoil, the soil organic carbon (SOC) and total nitrogen (N) content was found to increase along the soil chronosequence and were highly correlated with vegetation-associated variables. These findings suggest that plant-derived material was the main driver of the light fraction of SOM accumulation in the topsoil. The heavy fractions of SOM were composed of microbially transformed organic compounds, eventually contributing to SOM stabilization within short 90-yr deglaciation under harsh climatic conditions. In addition to time, the soil vertical profiles showed that other environmental parameters, also affected the soil biogeochemical properties. The high total phosphorous (P) content and elec- trical conductivity in the topsoil were attributed to unweathered subglacial materials and a considerable amount of inorganic ions from subglacial meltwater. The high P and magnesium content in the subsoil were attributed to parent materials, while the high sodium and potassium content in the surface soil were a result of sea-salt deposition. Glacio-fluvial runoff hampered ecosystem development by inhibiting vegetation development and SOM accumulation. This study emphasizes the importance of considering various soil-forming factors, including parent/subglacial materials, aeolian deposition, and glacio-fluvial runoff, as well as soil age, to obtain a comprehensive understanding of the ecosystem development in glacier forelands.

This paper applied different data fusion methods including Maximum Likelihood Estimation (MLE) and Linear Regression methods on satellite images over Vietnam areas from Moderate Resolution Imaging Spectroradiometer (MODIS) and Visible Infrared Imaging Radiometer Suite (VIIRS) sensors. In comparison with ground station Aerosol Robotic Network (AERONET), the regression method is better than Maximum Likelihood Estimator (MLE). Our results show that the fusion methods can improve both data coverage and quality of satellite aerosol optical depth (AOD). Strong correlations were observed between fused AOD and AERONET AOD (R2 = 0.8118, 0.7511 for Terra regression and MLE method, respectively). This paper presented the evaluation of data fusion algorithm and highlighted its importance on the satellite AOD data coverage and quality methods from multiple sensors.

In this study, several georeferencing methods such as Polynomial, Thin Plate Spline (TPS) and geolocation transformations are applied on satellite images over Vietnam areas from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard Terra/Aqua satellites and Visible Infrared Imaging Radiometer Suite (VIIRS) sensor aboard the Suomi National Polar-orbiting Partnership (NPP) satellite. In comparison with global administrative areas data, the georeferenced images of TPS function have a better fitting than Polynomial function. In addition, the experimental results highlighted the effect of georeferencing methods on satellite aerosol optical depth (AOD) data in which TPS function produce a higher quality than Polynomial function on both MODIS Terra/Aqua and VIIRS AOD images. Validation results indicated strong correlation between AERONET AOD and TPS georeferenced images (R2 = 0.739, 0.537 and 0.596 for MODIS Terra, MODIS Aqua and VIIRS AOD, respectively) meanwhile these correlations of Polynomial are lower (R2 = 0.596, 0.443 and 0.475 for MODIS Terra, MODIS Aqua and VIIRS AOD, respectively). The correlations between MODIS AOD and VIIRS AOD images are also affected by georeferencing methods. The average of these correlations on TPS georeferenced images is 0.72 meanwhile mean correlation of Polynomial is 0.51. This study focused on the assessment of georeferencing methods and highlighted the effect of these methods on the quality and correlation of satellite AOD images.

Global warming has accelerated glacial retreat in the high Arctic. The exposed glacier foreland is an ideal place to study chronosequential changes in ecosystems. Although vegetation succession in the glacier forelands has been studied intensively, little is known about the microbial community structure in these environments. Therefore, this study focused on how glacial retreat influences the bacterial community structure and its relationship with soil properties. This study was conducted in the foreland of the Midtre Lovenbreen glacier in Svalbard (78.9°N). Seven soil samples of different ages were collected and analyzed for moisture content, pH, soil organic carbon and total nitrogen contents, and soil organic matter fractionation. In addition, the structure of the bacterial community was determined via pyrosequencing analysis of 16S rRNA genes. The physical and chemical properties of soil varied significantly along the distance from the glacier; with increasing distance, more amounts of clay and soil organic carbon contents were observed. In addition, Cyanobacteria, Firmicutes, and Actinobacteria were dominant in soil samples taken close to the glacier, whereas Acidobacteria were abundant further away from the glacier. Diversity indices indicated that the bacterial community changed from homogeneous to heterogeneous structure along the glacier chronosequence/distance from the glacier. Although the bacterial community structure differed on basis of the presence or absence of plants, the soil properties varied depending on soil age. These findings suggest that bacterial succession occurs over time in glacier forelands but on a timescale that is dif ferent from that of soil development.

Satellite observations for regional air quality assessment rely on comprehensive spatial coverage, and daily monitoring with reliable, cloud-free data quality. We investigated spatiotemporal variation and data quality of two global satellite Aerosol Optical Depth (AOD) products derived from MODIS and VIIRS imagery. AOD is considered an essential atmospheric parameter strongly related to ground Particulate Matter (PM) in Southeast Asia (SEA). We analyze seasonal variation, urban/rural area influence, and biomass burning effects on atmospheric pollution. Validation indicated a strong relationship between AERONET ground AOD and both MODIS AOD (R2 = 0.81) and VIIRS AOD (R2 = 0.68). The monthly variation of satellite AOD and AERONET AOD reflects two seasonal trends of air quality separately for mainland countries including Myanmar, Laos, Cambodia, Thailand, Vietnam, and Taiwan, Hong Kong, and for maritime countries consisting of Indonesia, Philippines, Malaysia, Brunei, Singapore, and Timor Leste. The mainland SEA has a pattern of monthly AOD variation in which AODs peak in March/April, decreasing during wet season from May–September, and increasing to the second peak in October. However, in maritime SEA, AOD concentration peaks in October. The three countries with the highest annual satellite AODs are Singapore, Hong Kong, and Vietnam. High urban population proportions in Singapore (40.7%) and Hong Kong (21.6%) were associated with high AOD concentrations as expected. AOD values in SEA urban areas were a factor of 1.4 higher than in rural areas, with respective averages of 0.477 and 0.336. The AOD values varied proportionately to the frequency of biomass burning in which both active fires and AOD peak in March/April and September/October. Peak AOD in September/October in some countries could be related to pollutant transport of Indonesia forest fires. This study analyzed satellite aerosol product quality in relation to AERONET in SEA countries and highlighted framework of air quality assessment over a large, complicated region.

International audience; In this study we estimate relative pollen productivity (RPP) for plant taxa characteristic of human-induced vegetation in ancient cultural landscapes of the low mountain ranges of Shandong province in eastern temperate China. RPP estimates are required to achieve pollen-based reconstructions of Holocene plant cover using modelling approaches based on Prentice’s and Sugita’s theoretical background and models (REVEALS and LOVE). Pollen counts in moss samples and vegetation data from 36 sites were used in the Extended R-Value (ERV) model to estimate the relevant source area of pollen (RSAP) of moss polsters and RPP of major plant taxa. The best results were obtained with the ERV sub-model 3 and Prentice’s taxon-specific method (using a Gaussian Plume dispersal model) to distance weight vegetation data. RSAP was estimated to 145 m using the maximum likelihood method. RPP was obtained for 18 taxa of which two taxa had unreliable RPP (Amaranthaceae/Chenopodiaceae and Vitex negundo). RPPs for Castanea, Cupressaceae, Robinia/Sophora, Aster/Anthemis-type, Cannabis/Humulus, Caryophyllaceae, Brassicaceae and Galium-type are the first ones for China. Trees, except Robinia/Sophora (RPP = 0.78 ± 0.03) have larger RPPs than herbs other than Artemisia (RPP = 24.7 ± 0.36). The RPPs for Quercus, Pinus and Artemisia are comparable with other RPPs obtained in China, the RPPs for Pinus, Quercus, Ulmus, Cyperaceae and Galium-type with the mean RPPs obtained in Europe, and RPP for Cupressaceae with that for Juniperus in Europe. The values for Aster/Anthemis-type, Caryophyllaceae, Asteraceae SF Cichorioideae and Juglans differ from the few RPPs available in China and/or Europe.

International audience

In order to analyze environmental dynamics, a major process is the classification of the different phenomena of the site (e.g. ice and snow for a glacier). When using in situ pictures, this classification requires data pre-processing. Not all the pictures need the same sequence of processes depending on the disturbances. Until now, these sequences have been done manually, which restricts the processing of large amount of data. In this paper, we present how to realize a semantic orchestration to automate the sequencing for the analysis. It combines two advantages: solving the problem of the amount of processing, and diversifying the possibilities in the data processing. We define a BPEL description to express the sequences. This BPEL uses some web services to run the data processing. Each web service is semantically annotated using an ontology of image processing. The dynamic modification of the BPEL is done using SPARQL queries on these annotated web services. The results obtained by a prototype implementing this method validate the construction of the different workflows that can be applied to a large number of pictures.

Open Data now provides access to updated data dedicated to urban development. The traditional approach of using production data for decision on land management needs to be rethought in the light of these new opportunities and should therefore addressed towards dynamic management of geographic information. Institutional sites such as INSEE semantically annotate their data facilitating the discovery of contextual data. Linked Open Data cloud network offers semantic access to a huge amount of thematic data including an important geographic subset. These new opportunities always generate a greater amount of usable data. Big Data tools, like Spark, make it easy to handle this amount unbounded data via conventional data-mining algorithms. We group all these issues under the generic name of Cloud Data that has sense only if it is integrated perfectly into a cloud computing environment for efficient processing and reactive application (SaaS application, Restfull services, D3JS library, …). We offer an example of a dedicated application for the Pau urban community in which all Cloud Data is integrated as a SaaS (Software as a Service).

This study deals with land use land cover change and its driving forces in the Ha Long bay area, Vietnam. Land use land cover transitions were detected by analyzing a series of Landsat satellite images from 1973 to 2013. A survey (600 individuals) in the 3 districts about the socio-spatial practices and their evolution from recent past show a strong impact caused by industrialization and urbanization. These consequences are strongly linked by the geography and we try to link them to the landscape changes using multivariate analysis. We propose a methodological solution - founded on Multiple Correspondence Analysis - who help to find a way in the difficult link between what we can measure from above (RS) and what people are doing on the field in the real life (survey) that given landscape. Because if it's very easy to explain that landscape is the result of these interactions it's inversely proportionally more difficult to demonstrate. Hope our proposal offers one of possible keys

To date, there is no definitive approach to map snow depth in mountainous areas from spaceborne sensors. Here, we examine the potential of very-high-resolution (VHR) optical stereo satellites to this purpose. Two triplets of 0.70 m resolution images were acquired by the Pléiades satellite over an open alpine catchment (14.5 km2) under snow-free and snow-covered conditions. The open-source software Ame's Stereo Pipeline (ASP) was used to match the stereo pairs without ground control points to generate raw photogrammetric clouds and to convert them into high-resolution digital elevation models (DEMs) at 1, 2, and 4 m resolutions. The DEM differences (dDEMs) were computed after 3-D coregistration, including a correction of a −0.48 m vertical bias. The bias-corrected dDEM maps were compared to 451 snow-probe measurements. The results show a decimetric accuracy and precision in the Pléiades-derived snow depths. The median of the residuals is −0.16 m, with a standard deviation (SD) of 0.58 m at a pixel size of 2 m. We compared the 2 m Pléiades dDEM to a 2 m dDEM that was based on a winged unmanned aircraft vehicle (UAV) photogrammetric survey that was performed on the same winter date over a portion of the catchment (3.1 km2). The UAV-derived snow depth map exhibits the same patterns as the Pléiades-derived snow map, with a median of −0.11 m and a SD of 0.62 m when compared to the snow-probe measurements. The Pléiades images benefit from a very broad radiometric range (12 bits), allowing a high correlation success rate over the snow-covered areas. This study demonstrates the value of VHR stereo satellite imagery to map snow depth in remote mountainous areas even when no field data are available.

Mercury is known to be a powerful neurotoxin, particularly in its organic form. Amazonian populations living along contaminated rivers are exposed to mercurial contamination through fish consumption, but spatial disparities of contamination have very seldom been explored. The problem was addressed along the river Beni, in the Bolivian Amazon. Fifteen communities have been studied by a multidisciplinary research team, to explore the socio-geographical determinants of contamination by mercury. Using quantitative and qualitative methods, from the community to the regional level, this paper shows how spatial contrasts of mercury contamination are determined by contrasted types of resource management and contrasted social networks from one community to another, and how the places’ and societies’ specificities play an essential role in the determination of the mercurial risk.

Health geography in France has -for nearly a century now -contributed to the understanding of health inequalities in countries of the northern and southern hemispheres. Even though its conceptual structure and methodology were for the most part initially developed through the study of vector-borne diseases, health geography has subsequently extended its scope through focussing on emerging health issues. This presentation will demonstrate how a highly fruitful method, widely applied to the understanding of health inequalities of communicable diseases, has allowed us to engage in a novel health issue, barely explored by geographers so far : the study of the exposure in the long term to low level contamination by pollutants. With the example of mercury contamination disparities in the Bolivian Amazon region, this presentation confirms the efficiency of this method, which constitutes a starting point for the development of future research on the subject of environmental pollution., La géographie de la santé en France contribue depuis près d'un siècle à la compréhension des inégalités de santé dans les pays du Sud comme du Nord. Si son cadre conceptuel s'est forgé pour beaucoup grâce à l'étude des maladies transmissibles, elle s'est également largement renouvelée en se penchant sur les maux de son temps. Cette communication montre comment une démarche fructueuse largement appliquée à la compréhension des inégalités de santé liées aux maladies transmissibles a permis de revisiter et d'apporter un éclairage nouveau sur une thématique sanitaire encore peu explorée par les géographes : la contamination sur le long terme à de faibles doses de polluants. A travers l'étude des disparités de contamination par le mercure en Amazonie bolivienne, cette communication confirme l'efficacité de cette méthode, qui constitue une porte d'entrée pour le développement de futures recherches sur le thème des pollutions environnementales., Tschirhart Céline, Handschumacher Pascal, Laffly Dominique, Piermay Jean-Luc, Blanc Maurice, Luna Selma, Benefice Eric. Inégalités de contamination par le mercure le long du rio Béni (Bolivie) : un marqueur de l'inégale gestion et pratique des espaces par les communautés (Uneven mercury contamination alongside Rio Beni, Bolivia : a marker of uneven management and spatial practices by communities). In: Bulletin de l'Association de géographes français, 89e année, 2012-2. La géographie de la santé en France, sous la direction de Jeanne-Marie Amat-Roze. pp. 337-350.

The volume variation of a glacier is the actual indicator of long term and short term evolution of the glacier behaviour. In order to assess the volume evolution of the Austre Lovénbreen (79° N) over the last 47 years, we used multiple historical datasets, complemented with our high density GPS tracks acquired in 2007 and 2010. The improved altitude resolution of recent measurement techniques, including phase corrected GPS and LiDAR, reduces the time interval between datasets used for volume subtraction in order to compute the mass balance. We estimate the sub-metre elevation accuracy of most recent measurement techniques to be sufficient to record ice thickness evolutions occurring over a 3 year duration at polar latitudes.The systematic discrepancy between ablation stake measurements and DEM analysis, widely reported in the literature as well as in the current study, yields new questions concerning the similarity and relationship between these two measurement methods.The use of Digital Elevation Model (DEM) has been an attractive alternative measurement technique to estimate glacier area and volume evolution over time with respect to the classical in situ measurement techniques based on ablation stakes. With the availability of historical datasets, whether from ground based maps, aerial photography or satellite data acquisition, such a glacier volume estimate strategy allows for the extension of the analysis duration beyond the current research programmes. Furthermore, these methods do provide a continuous spatial coverage defined by its cell size whereas interpolations based on a limited number of stakes display large spatial uncertainties. In this document, we focus on estimating the altitude accuracy of various datasets acquired between 1962 and 2010, using various techniques ranging from topographic maps to dual frequency skidoo-tracked GPS receivers and the classical aerial and satellite photogrammetric techniques.

Climatic changes since the end of the Little Ice Age have considerably disturbed environmental balances of plant colonization in high latitudes. Within one century on Spitsbergen, valley glaciers have retreated up to one kilometre from their original terminus as of 1918, affecting several hundred hectares of two types of landscape processes: plant colonization and paraglacial morphogenesis. Since these processes are limited to the chronological position of the old ice-front it is possible to know the rate of plant colonization by both qualitative and quantitative means, as well as speculate on the processes involved, such as the effects of runoff. The present study is limited to the Midtre Lovenbreen forefield (latitude 79°N, longitude 12°E), where geomorphologic and floristic samples were collected in 2003. On stable deposits in this area, the settlement and the evolution of floristic groups have been documented. During this time period of colonization, the plain areas are reworked by runoff at a kilometric scale, and are characterized as similar to their surrounding biogeographic landscapes. Thus, a relationship can be observed between the paraglacial process occurring in the proglacial forelands and surrounding stable surfaces on till deposits. These features that occur as spatial discontinuities across the landscape are perceptible through either plant colonization or disturbance to vegetation caused by hydrological processes. Ultimately, however, runoff dynamics maintain pioneer vegetation groups which are superimposed on plant colonization that are driven by temporal periods of deglaciation. Differences in the rates and the nature of plant colonization are biomarkers of paraglacial dynamics.

Little is known about the fluctuations of the Pyrenean glaciers. In this study, we reconstructed the evolution of Ossoue Glacier (42°46' N, 0.45 km2), which is located in the central Pyrenees, from the Little Ice Age (LIA) onwards. To do so, length, area, thickness, and mass changes in the glacier were generated from historical data sets, topographical surveys, glaciological measurements (2001–2013), a ground penetrating radar (GPR) survey (2006), and stereoscopic satellite images (2013). The glacier has receded considerably since the end of the LIA, losing 40 % of its length and 60 % of its area. Three periods of marked ice depletion were identified: 1850–1890, 1928–1950, and 1983–2013, as well as two short periods of stabilization: 1890–1894, 1905–1913, and a longer period of slight growth: 1950–1983; these agree with other Pyrenean glacier reconstructions (Maladeta, Coronas, Taillon glaciers). Pyrenean and Alpine glaciers exhibit similar multidecadal variations during the 20th century, with a stable period detected at the end of the 1970s and periods of ice depletion during the 1940s and since the 1980s. Ossoue Glacier fluctuations generally concur with climatic data (air temperature, precipitation, North Atlantic Oscillation, Atlantic Multidecadal Oscillation). Geodetic mass balance over 1983–2013 was −1.04 ± 0.06 w.e.a−1 (−31.3 ± 1.9 m w.e.), whereas glaciological mass balance was −1.45 ± 0.85 m w.e. a−1 (−17.3 ± 2.9 m w.e.) over 2001–2013, resulting in a doubling of the ablation rate in the last decade. In 2013 the maximum ice thickness was 59 ± 10.3 m. Assuming that the current ablation rate remains constant, Ossoue Glacier will disappear midway through the 21st century.

Svalbard belongs to the polar oceanic environment that records contemporary Global Change with an acute sensitivity. In a periglacial context, runoff, an active azonal erosion process, sets itself at the top of the morphogenic hierarchy in a polar environment, relegating glacial and periglacial cold-related processes to a lesser level of influence. In Svalbard, since the end of the Little Ice Age, sandurs record morphological manifestations of runoff water coming from melting glaciers. Remote sensing data (SPOT XSP), together with precise field observation in the Brogger peninsula (79° N, 12° E), provide an efficient method to show the changes in these outwash plains. In this paper, a method for cartography and acquisition of field data is introduced, which is founded on a systematic non-aligned survey. The morphodynamic results show a large prograding shoreline was observed at the down sides of the sandurs, which gain ground over the space occupied by the fjords owing to a substantial amount of sediments...

As satellite imaging is quite expensive, and because of poor weather conditions including common heavy cloud cover at polar latitudes, daily satellite imaging is not always accessible or suitable to observe fast temporal evolutions. We complement satellite imagery with a set of ground based autonomous automated digital cameras which take three pictures a day. With these pictures we build a mosaic with their projection and apply a classification to define the temporal evolution of the snow cover. As the pictures are subject to heavy disturbance, some processing is needed to build the mosaic. Once the processes are defined, we present our model. This model is built upon a cloud computing environment using Web services workflow. Then we present how the processes are dynamically organized using a scheduler. This scheduler chooses the order and the processes to apply to every picture to build the mosaic. Once we obtain a mosaic we can study the variation of the snow cover.

Sleeping Sickness in Ivory Coast : in Search of Risk Indicators. Sleeping Sickness (Human African Trypanosomiasis, H.A.T.) is a lethal vector born parasitic disease actually re-emerging. Health care structures are not, actually, able to control this pathology without specific symptoms. The main question, today, is to be able to determine exactly where priorities are without medical or entomological information. Environmental characteristics of the pathology allow to identify eco-demographic indicators in order to trace out geographic roots of sleeping sickness., La maladie du sommeil, ou Trypanosomiase Humaine Africaine (T.H.A.), est une maladie parasitaire à transmission vectorielle mortelle. Elle est, aujourd'hui, qualifiée de « reviviscente ». Les structures de soins ne semblent plus, actuellement, aptes à contrôler cette maladie sans signes d'appel spécifiques. La question principale qui se pose, alors, aux programmes nationaux de lutte est de savoir où agir en priorité, en l'absence d'informations médicales ou entomolo- giques fiables. Cette maladie possède cependant des caractères environnementaux affirmés. Des indicateurs éco-démographiques de celle-ci, toujours complexes, peuvent être dégagés afin de retracer ses racines géographiques., Hervouët Jean-Pierre, Laffly Dominique, Cardon Laetitia. La maladie du sommeil en Côte d'Ivoire : à la recherche d'indicateurs de risque. In: Espace, populations, sociétés, 2000-2. Maladies émergeantes et reviviscentes. pp. 209-225.

High spatial resolution satellite imagery used together with geographical information systems produce interesting results for the ecology. For example, we present a study of the capercaillie's ecotopes in the Jura highlands, carried out in two steps : a supervised analysis of image texture on panchromatics Spot data then integration of this structure in topographic and thematic data through a GIS. The obtained results appear as potential surface maps so as to be capercaillie's ecotopes., Utilisés conjointement, les données de satellites à haute résolution spatiale et les systèmes d'informations géographiques fournissent des résultats intéressants pour l'écologie. À titre d'exemple, nous présentons une étude des écotopes du grand tétras dans le massif du Jura, réalisée en deux temps : une analyse de texture d''image (Spot panchromatique), son intégration à des données topographiques et thématiques par l'intermédiaire d'un SIG. Les résultats obtenus se présentent sous la forme de cartes de potentiels des milieux à accueillir le grand tétras., Utilizadas conjuntamente, las imágenes satelitarias de alta resolución espacial y los sistemas de información geográfica dan resultados interesantes para la ecología. A título de ejemplo, presentamos un estudio de los ecotopos del uragollo en el macizo de Jura, realizado en dos tiempos : un análisis supervisado de textura de imagen sobre datos Spot pancromático y luego la integración de esa textura a datos topográficos y temáticos a través de un SIG. Los resultados obtenidos se presentan en forma de medios potenciales de los ecotopos del urogallo., Laffly Dominique. Écologie, télédétection et SIG: les écotopes du grand tétras dans le Haut-Jura. In: Mappemonde, 1997/3. pp. 27-30.