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See detailEvaluation of geochemical determinism of trace elements in forest soils at regional scales. Lessons from the Permanent Forest Condition Survey.
Colinet, Gilles ULg; Baize, Denis; Lacroix, Daniel et al

Conference (2006)

The natural concentration of some elements in soil varies regionally according to lithology and locally with site-specific soil forming conditions such as relief or vegetation characteristics. Knowledge ... [more ▼]

The natural concentration of some elements in soil varies regionally according to lithology and locally with site-specific soil forming conditions such as relief or vegetation characteristics. Knowledge of the natural total concentrations of trace metals is now considered as prerequisite for the detection and assesment of anthropogenic contaminations. The Permanent Forest Inventory is a programme financed by the Ministry of the Walloon Region which aims at assessing and monitoring the forest condition in Southern Belgium. A part of this programme is dedicated to the implementation of a soil quality monitoring network. The observation plots are located at the intersection of a regular grid. Ten percent of the forest plots are planned to be sampled each year, which theorically supposes a time-frequency of 10 years for the monitoring considerations. Up to now, three field campaigns have been completed and 245 soil samples analyzed. Once a plot precisely located on the field, soil is sampled by mixing twenty 20cm-deep cores taken at the perimeter of a 10m large circle. Environmental observations complete the field work. These concern the physical environment, the soil morphology and the vegetation characteristics. The following parameters are measured in the laboratory: total organic carbon, total nitrogen, pHwater, pHKCl, exchangeable acidity and aluminium, cationic exchangeable capacity, NH4Cl-exctractible cations, total, mineral, and exchangeable P, and aqua-regia extractible concentrations of Ca, Mg, K, Al, Fe, Cr, Ni, Mn, Zn, Cu, Pb, Co, and Cd. Statistical analysis were then performed on the results in order to identify the driving factors of the soil properties, especially the geochemical determinism. Relationships between parameters and between parameters and field observations were thus investigated. Then the relevance of some classifications to differenciate the soil properties was evaluated and finally the spatial structure of the parameters was compared to the geographical distribution patterns of lithology, soil associations, or ecological territories. Although some diversity can be found among the soil series in this survey, soils developped from shales and/or sandstones are largely dominant. The first results therefore show a large extreme-based variability and moderate variation coefficients. The exchangeable cations and carbonate–sensitive parameters are the most variable. Frequency distributions are often largely skewed. Exchangeable cations appear to be more closely linked to acidity status than organic content while pseudo-total concentrations show rather good linear relationships between each other, to the exception of Pb and Cd. Both elements seem linked to specific lithologies, the presence of limestone for Pb, some clay-rich parent material or limestone for Cd. Among the soil characteristics, the nature and the abundance of the coarse fragments associated to the fine earth is the most differenciating criteria for pseudo-total content. Finally, there are clear convergences between spatial distributions of most of the elements and lithology or small natural regions. [less ▲]

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See detailRelevance of soil mapping criteria to predict geochemical background of trace elements in soils from local to regional scales.
Colinet, Gilles ULg; Bogaert, Patrick; Bock, Laurent ULg

Poster (2006)

Among natural factors driving the soil content in metallic trace elements (MTE), the geochemical background is often deemed as a sound base for the detection of contaminations. Numerous studies have shown ... [more ▼]

Among natural factors driving the soil content in metallic trace elements (MTE), the geochemical background is often deemed as a sound base for the detection of contaminations. Numerous studies have shown the difficulties to take into account the multi-dimensionnality of the spatial variability of most soil properties. As far as a detailed soil map is available for Belgium, the relevance of its information was investigated at various spatial scales in the Walloon Region (Southern Belgium), from the plot to the entire region, to evaluate the feasibility of a multi-scale mapping of geochemical background. A database of soil profiles (gathering both agricultural and forest soils) was used to analyse the relationships between the MTE total content (measured after HF-HClO4-HCl dissolution) and other general characteristics such as pH, Total Organic Carbon content (TOC), Particle Size Distribution (PSD), and cationic exchange capacity (CEC). The factors of MTE spatial distribution inside and between solums were investigated through multivariate statistical analysis. The spatial dependence of these factors was then studied over plot, field, farm, county and region scales, and compared to the spatial structures of the soil map parameters. At the solum level, strong relationships between most of the studied MTE were found, as well as between stone charge and fine earth contents. The PSD is the main driving factor of MTE content in non-carbonated soils, whatever the land use. When considering soil associations, such as catenas, the slope redistribution processes must be taken into account. However, the PSD remains the main driving factors and, as the soil map contains information about that property (mainly the textural class and the profile development), a cartography of the geochemical background based on the use of the soil map and pedotransfer functions or regression models appears relevant. At the regional scale, some long-range spatial structures could be identified. These result mainly from the geological structure of the Walloon region, where the lithological zonation is rather clearly marked. The soil map (texture and nature of stone charge) appears relevant at that scale too but does need a generalization process and fails however to differenciate the intra-type soil spatial variability. Some basic processes of integration of point measurements and qualitative information have been explored. They should be further investigated in the future. [less ▲]

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See detailContribution to the evaluation of soil quality around the Naivasha lake (Kenya).
Borgers, nathalie; Colinet, Gilles ULg; Gouder de Beauregard, Anne-Christine et al

Poster (2005, September)

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See detailThe Digital Soil Map of Wallonia (Southern Belgium). A tool for better soil management
Bah, Boubacar Billo ULg; Veron, Philippe; Bracke, Charles et al

Conference (2005, July)

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See detailThe digital soil map of Wallonia (DSMW/CNSW)
Veron, Philippe; Bah, Boubacar Billo ULg; Bracke, Charles et al

in The International Cartographic Association (ICA-ACI) (Ed.) XXII International Cartographic Conference (ICC2005), A Coruña, Spain, 11-16 July 2005 (2005, July)

Based on the Belgian soil map at 1/20,000, this digital map of Wallonia (DSMW) is composed of a cartographic database describing the soil characteristics of the region. Tool for a better soil management ... [more ▼]

Based on the Belgian soil map at 1/20,000, this digital map of Wallonia (DSMW) is composed of a cartographic database describing the soil characteristics of the region. Tool for a better soil management, this database will be integrated in a geographical information system where the soil layer could be used in relation with information concerning other aspects of land development. The different operations include : map drawing finalization of non edited sheets, creation of an image layer, vectorial capture of source objects, building up of the topology, characterization of the objects, geometrical corrections, creation of a continuous layer (edge-matching), creation of a homogeneous legend, integration in a geodatabase. The DSMW in figures corresponds to : 16,000 km2; 600,000 soil polygons delimited by 15 million intermediate points (vertex); 6,000 pedological symbols; 700MB. The advantages of this computerized cartographic database are continuity, legibility, accessibility and many possibilities of thematic analyses. [less ▲]

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See detailPrincipaux types de sols de la Région wallonne 1/750.000
Bock, Laurent ULg; Lejeune, Philippe ULg; Veron, Philippe et al

Cartographic material (2005)

Carte des principaux types de sols de Wallonie.

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See detailUse of soil properties and major element composition to predict background levels of trace elements in soils
Colinet, Gilles ULg; Carletti, Isabelle; Bock, Laurent ULg

Conference (2005)

The usefulness of various soil parameters to predict naturally occurring levels of some metallic trace elements (MTE) in soils has been studied for some agricultural and forest soils of Southern Belgium ... [more ▼]

The usefulness of various soil parameters to predict naturally occurring levels of some metallic trace elements (MTE) in soils has been studied for some agricultural and forest soils of Southern Belgium. The driving factors of the content in Cu, Ni, Pb, and Zn were investigated through multi-scale comparisons. This paper deals with multivariate and regression analysis of the results. [less ▲]

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See detailComparaison de différentes méthodes de détermination des teneurs en éléments majeurs et traces dans les sols.
Colinet, Gilles ULg; Baize, Denis; Delcarte, Emile et al

in Actes des 8emes JNES (2004, October)

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See detailEnseigner la pédologie opérationnelle en faculté d'agronomie
Bock, Laurent ULg

Scientific conference (2004, March 17)

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See detailIntérêt d'une stratification pédologique pour la constitution de référentiels régionaux sur les teneurs en éléments traces métalliques dans les sols de Wallonie
Colinet, Gilles ULg; Laroche, Jean; Etienne, Marie et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2004), 8(2)

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See detailMise en oeuvre du projet de Cartographie Numérique des Sols de Wallonie (P.C.N.S.W.)
Lejeune, Philippe ULg; Rondeux, Jacques ULg; Bock, Laurent ULg et al

Report (2004)

Ce rapport final présente la synthèse de l'ensemble des activités menées dans le cadre de la convention d'étude pour la "Mise en oeuvre du projet de cartographie numérique des sols de Wallonie". L ... [more ▼]

Ce rapport final présente la synthèse de l'ensemble des activités menées dans le cadre de la convention d'étude pour la "Mise en oeuvre du projet de cartographie numérique des sols de Wallonie". L'objectif général de cette convention s'est déroulé sur la période du 1er février 2001 au 30 avril 2004. Objectif général : "Mise en oeuvre du projet de cartographie numérique des sols de Wallonie sur base de la carte des sols de l'I.R.S.IA." Objectifs particuliers : 1. Scannage et géoréférencement des planchettes couleurs éditées à 1/20 000. 2. Digitalisation des planchettes éditées (1/20 000) et non éditées (1/10 000) couvrant le territoire de la Région wallonne. 3. Evaluation de la faisabilité d'une récupération des planchettes ou parties de planchettes digitalisées dans le cadre des conventions financées par la Région. Le travail de digitalisation intégrera les considérations suivantes : * Géoréférencement des données cartographiques dans le système Lambert 72 ; * Ajustement des plages de sols de vallées et de dépressions par rapport au réseau hydrographique du fond topographique I.N.G. à 1/10 000 ; * Ajustement des plages de sols par rapport aux figures de terrain présentent sur le fond topographique I.G.N. à 1/10 000 ; * Etablissement de la continuité cartographique et thématique entre toutes les planchettes digitalisées ; * Mise au point d'une légende pédologique unique et homogène pour tout le territoire wallon. [less ▲]

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