1. Classification and mapping of anthropogenic landforms on cultivated hillslopes using DEMs and soil thickness data - Example from the SW Parisian Basin, France
- Author
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Sébastien Salvador-Blanes, Florent Hinschberger, Jean-Jacques Macaire, Hocine Bourennane, Caroline Chartin, Transferts continentaux : forçages anthropiques, climatiques et géodynamiques, Institut des Sciences de la Terre d'Orléans (ISTO), Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Université de Tours-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Université de Tours-Centre National de la Recherche Scientifique (CNRS), Unité de Science du Sol, Institut National de la Recherche Agronomique (INRA), Université de Tours (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Financial support provided by the ANR (Agence Nationale de la Recherche) VMCS project LANDSOIL is gratefully acknowledged. The authors would like to thank Jean-Paul Bakyono and Isabel Pene-Galland for data collection in the field. This paper was much improved thanks to the comments of Peter Houben and an anonymous referee and thanks to Lauren Valverde who revised my english style., and Chartin, Caroline
- Subjects
010504 meteorology & atmospheric sciences ,Soil test ,Morphometric attributes ,[SDE.MCG]Environmental Sciences/Global Changes ,Digital Elevation Model ,Structural basin ,bassin parisien ,Spatial distribution ,01 natural sciences ,Field borders ,Lynchet ,Digital elevation model ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,Geomorphology ,0105 earth and related environmental sciences ,Earth-Surface Processes ,geography ,geography.geographical_feature_category ,Landform ,anthropogenic landform ,predictive modelling ,parisian basin ,modèle numérique de terrain ,attribut morphométrique ,épaisseur du sol ,banquette ,parcellaire ,arbre de classification ,digital elevation model ,morphometric attribute ,soil thickness ,lynchet ,field border ,classification tree ,relief anthropique ,modélisation prédictive ,physical ,geosciences ,multidisciplinary ,geology ,04 agricultural and veterinary sciences ,15. Life on land ,Current (stream) ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Spatial variability ,Classification Tree ,Geology ,Soil thickness - Abstract
International audience; This study focuses on linear anthropogenic landforms of decametric width on cultivated hillslopes and their relations to soil thickness variability. The 16 ha study area shows a rolling topography supported by Cretaceous chalk of the SW Parisian Basin, France. Two types of landforms were identified: lynchets, similar to those described as soil terraces occurring on downslope field parts in other contexts, and undulations, linear, convex landforms that cut across fields. Accurate DEM construction and a detailed soil thickness survey were performed all over the study area. Soil samples were classified considering their location on specific types of anthropogenic landforms. The classification tree (CT) method was applied to assess whether lynchets and undulations can be discriminated through morphometric attributes (slope, curvature, profile curvature and planform curvature) and soil thickness (CTsoil) or through morphometric attributes only (CTtopo). The CT application establishes predictive classification models to map the spatial distribution of lynchets and undulations over the whole study area. The validation results of the CTsoil and CTtopo applications show model efficiencies of 83% and 67%, respectively. Both models performed well for lynchets. Errors arise mainly from difficulties in unequivocally discriminating gently convex undulations and undifferentiated surfaces, especially when soil thickness is not accounted for. Mean values of soil thickness are 1.08, 0.62 and 0.45 m in lynchets, undulations and undifferentiated areas, respectively. The general shape of the thickened soil is characteristic to each type of anthropogenic landform. Multi-temporal mapping of field border networks shows that undulations are linked to borders that were removed during the latest land consolidation. Lynchets are associated with current field borders. Lynchets and undulations, which cover 39% of the study area, define topographic indicators of human-induced soil accumulations. The method involves perspectives for efficiently mapping and quantifying the anthropogenically modified spatial variability of soil thickness on agricultural hillsides.
- Published
- 2011