References of "Legrain, Xavier"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailDiachronical soil surveys: a way to quantify long term diffuse erosion?
Pineux, Nathalie ULiege; Michel, Brieuc ULiege; Legrain, Xavier ULiege et al

in Geoderma Regional (2017), (10), 102-114

Because of high inter-annual variability, representative soil erosion measurements are best carried out over time scales of a few decades. In this paper, a novel approach was tested that relies on ... [more ▼]

Because of high inter-annual variability, representative soil erosion measurements are best carried out over time scales of a few decades. In this paper, a novel approach was tested that relies on diachronic, high-resolution soil mapping. For this purpose, a 116-ha, cropland-dominated watershed was selected in central Belgium. A first augering soil survey was carried out in 1956, with a density of 1.8 observation points /ha. A second survey was carried out in 2015 with a density of 4.5 observations/ha. The results were interpreted in terms of changes in depth of transitions between successive horizons. The results indicate that a great proportion of the soils classified as non-eroded in 1956 were strongly eroded in 2015. Strongly eroded soils represented 52% of the watershed area in 2015 but only 8% in 1956. Some colluvial areas have been subjected to erosion and then covered again by colluvium over the last 60 years. Only the flatter areas close to the watershed boundary appear to remain in the “non eroded soils or soil subject to weak erosion” class. A mean net erosion rate of 37 t/ha.yr is computed within the watershed with this method. The diachronic comparison of the pedological maps over a 60-year time interval in a context of intensive farming is a potential source of information for the calibration of landscape evolution spatial modelling. This method joins the few ones allowing a quantitative spatialization of erosion and deposition phenomena at the catchment scale. [less ▲]

Detailed reference viewed: 40 (13 ULiège)
See detailPrésentation des activités du PCNSW
Legrain, Xavier ULiege; Michel, Brieuc ULiege; Roda, Mathilde ULiege et al

Conference (2016, December 14)

Detailed reference viewed: 18 (2 ULiège)
See detailPrésentation des activités du PCNSW
Michel, Brieuc ULiege; Legrain, Xavier ULiege; Roda, Mathilde ULiege et al

Conference given outside the academic context (2016)

Detailed reference viewed: 15 (2 ULiège)
Full Text
See detailUtilisation de la carte des sols comme outil de gestion de la problématique carbone : mise en relation de la typologie des sols et des profils en carbone
Michel, Brieuc ULiege; Legrain, Xavier ULiege; Colinet, Gilles ULiege

Conference (2015, May 19)

La matière organique remplit plusieurs rôles essentiels dans le fonctionnement et la qualité des sols. La diminution du taux de matière organique dans les sols a été reconnue comme une des menaces ... [more ▼]

La matière organique remplit plusieurs rôles essentiels dans le fonctionnement et la qualité des sols. La diminution du taux de matière organique dans les sols a été reconnue comme une des menaces principales pesant sur ceux-ci, à l’échelle européenne. Si les données relatives aux teneurs en surface sont déjà nombreuses en Région wallonne, les profils de teneurs en fonction de la profondeur ont été moins caractérisés. Ils sont indispensables pour estimer les stocks de COT dans les sols. Afin d’estimer ces valeurs pour l’ensemble de la Région, la Wallonie dispose de deux outils historiques : la Carte Numérique des Sols de Wallonie et la base de données Aardewerk. La Carte Numérique contient des informations spatialisées des caractéristiques morphologiques des sols tandis que la base de données Aardewerk contient les informations d'une campagne de profilage effectuée en parallèle au levé de la carte. Les profils ont été décrits (sigle, type d’horizon, profondeur des horizons, etc.) et analysés pour chaque horizon (pH, carbone, texture, etc.). Ce travail se propose d’exploiter ces deux outils historiques afin de définir des profils de teneur en carbone en fonction de la typologie des sols. [less ▲]

Detailed reference viewed: 42 (4 ULiège)
See detailLes sols du bassin versant de l'Orneau
Legrain, Xavier ULiege; Bock, Laurent ULiege

Conference given outside the academic context (2015)

Detailed reference viewed: 13 (0 ULiège)
See detailSoil mapping in Wallonia - The PCNSW Team
Legrain, Xavier ULiege; Michel, Brieuc ULiege; Roda, Mathilde ULiege et al

Scientific conference (2015, April 24)

Detailed reference viewed: 23 (2 ULiège)
See detailLes sols dans leur terroir
Legrain, Xavier ULiege

Conference given outside the academic context (2015)

Detailed reference viewed: 11 (1 ULiège)
See detailTerroirs et cartes des sols
Legrain, Xavier ULiege

Conference given outside the academic context (2015)

Présentation de la diversité des sols de la commune d'Attert

Detailed reference viewed: 15 (3 ULiège)
Full Text
Peer Reviewed
See detailDiachronical soil surveys: a way to quantify long term diffuse erosion
Pineux, Nathalie ULiege; Michel, Brieuc ULiege; Legrain, Xavier ULiege et al

in Geophysical Research Abstracts (2015), 17

The loess belt of Western Europe is a high-risk area regarding diffuse erosion. It is due to the climate and the topography but also to the soil type. Loamy soils are naturally highly sensitive to diffuse ... [more ▼]

The loess belt of Western Europe is a high-risk area regarding diffuse erosion. It is due to the climate and the topography but also to the soil type. Loamy soils are naturally highly sensitive to diffuse erosion. Hence, these soils are very fertile. So, they are intensively cultivated which increases their sensitivity to erosion. Sheet erosion is an erosion type strongly represented in these regions. Contrarily to the concentrated form of erosion which happens more brutally, sheet erosion needs long-term observation time-scales, which remains rare. In Belgium, a soil map was established in 1956. This map is quite detailed and notably informs about the different horizons which are in the profile (ploughed horizon, eluvial horizon, clay included between the horizons, carbonate-free loess horizon, and all these were characterised by drainage class) and their depth. It was based on a dense augering network across the country (one point every 75 meters). A new augering campaign was done again in 2014. It consisted in one observation every 50 meters on an agricultural watershed of 124 hectares located in the centre of Belgium. This catchment has been cultivated since the 14th century and is representative of the local context (gentle slope (3-8%), plot size (mean value of 10 ha), …). We compared the two soil maps produced on this site with a 58years time lapse. Results show that the large majority of the watershed falls from upslope soils with weak erosion to slope soils with strong erosion. The soil thickness diminished in some zones to 1m10 (minimum estimation) of erosion. This comparison shows that very few upslope soils are preserved. On the other hand, the areas where colluviums were present to the full depth stay at the same place in the main thalweg of the watershed. Other areas on the watershed seem to be subject to a (minimum estimation) of 40cm of sediments deposition. Large areas in the watershed suffered from erosion and came to deposition areas as the clay horizon is no longer observed under the colluviums. It can be highlighted that soil depths were worryingly lost during 58 years of tillage and that some soils were converted to colluviums which is of lower agronomical quality than the original soils which had a clay horizon below to keep water. Diachronical soil survey offers an unique insight of long term diffuse erosion and should demonstrate the importance of preserving soils even in regions where agricultural yields are not (yet) affected by erosion. [less ▲]

Detailed reference viewed: 39 (9 ULiège)
See detailPrésentation des activités du PCNSW
Legrain, Xavier ULiege; Michel, Brieuc ULiege; Roda, Mathilde ULiege et al

Scientific conference (2014, December 12)

Detailed reference viewed: 23 (2 ULiège)