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Optimal resolution of soil properties maps varies according to their geographical extent and location / Christian Piedallu in Geoderma, vol 412 (15 April 2022)  

Public [article]  inGeoderma > vol 412 (15 April 2022) . - n° 115723 Titre : Optimal resolution of soil properties maps varies according to their geographical extent and location Type de document : Article/Communication Auteurs : Christian Piedallu, Auteur ; Eloïse Pedersoli, Auteur ; Emeline Chaste, Auteur ; François Morneau , Auteur ; Ingrid Seynave, Auteur ; Jean-Claude Gégout, Auteur Année de publication : 2022 Projets : 3-projet - voir note / Article en page(s) : n° 115723 Note générale : bibliographie This study was funded through the Rescale project by the Regional Council of Grand-Est (“Region Grand-Est”) and the “Direction de l’Agriculture et de la Forêt (DRAF) “Grand-Est. Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Cartographie thématique [Termes IGN] azote [Termes IGN] carbone [Termes IGN] carte pédologique [Termes IGN] échelle cartographique [Termes IGN] Grand Est (région 2016) [Termes IGN] inventaire forestier national (données France) [Termes IGN] pédologie locale [Termes IGN] potentiel hydrogène [Termes IGN] précision cartographique Résumé : (auteur) The important development of digital soil mapping (DSM) these last decades has led to a large number of maps of soil properties with increasingly finer raster size. Map resolution is mostly determined by expert knowledge or by matching with the resolution of existing data, while scale is recognized as a major issue. Using the pH and the C/N ratio describing the surface horizon of forest soils and estimated by bioindication, we evaluated the effect of resolution changes on model and map performance for different geographical extents. Using 40,663 plots from the national forest inventory and 25 environmental variables calculated at eight different spatial resolution levels (50, 100, 250, 500, 1000, 8000, 16,000, and 50,000 m), we modeled and mapped pH and C/N over a vast and diversified area of 91,000 km2 in the north-east of France. The models highlighted the importance of geology in pH and C/N spatial variations, and to a lesser extent the importance of stand type, climate and topography, with a slight influence of data resolution on predictor selection. On the contrary, the accuracy of model or map performance decreased significantly above 1000 m resolution. Significant performance differences were observed according to the location and the size of the geographical extent. Globally, the more heterogeneous environmental characteristics and the smaller the geographical extent, the better fine spatial resolution performed. In addition, the aggregation of fine-resolution pH or C/N maps at a coarser cell size improved map performance as compared to the direct use of the coarse-resolution predictors. The impact of resolution changes on map accuracy varies according to the mapping procedure, the local environment, and the geographical extent, and should be evaluated in DSM studies to optimize map accuracy. Numéro de notice : A2022-141 Affiliation des auteurs : IGN+Ext (2020- ) Autre URL associée : vers HAL Thématique : FORET/GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.geoderma.2022.115723 Date de publication en ligne : 01/02/2022 En ligne : https://doi.org/10.1016/j.geoderma.2022.115723 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99953 [article]

Electrical resistivity, remote sensing and geographic information system approach for mapping groundwater potential zones in coastal aquifers of Gurpur watershed / H.S. Virupaksha in Geocarto international, vol 36 n° 8 ([01/05/2021])  

Public [article]  inGeocarto international > vol 36 n° 8 [01/05/2021] . - pp 888 - 902 Titre : Electrical resistivity, remote sensing and geographic information system approach for mapping groundwater potential zones in coastal aquifers of Gurpur watershed Type de document : Article/Communication Auteurs : H.S. Virupaksha, Auteur ; K.N. Lokesh, Auteur Année de publication : 2021 Article en page(s) : pp 888 - 902 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] aquifère [Termes IGN] bassin hydrographique [Termes IGN] carte des pentes [Termes IGN] carte hydrogéologique [Termes IGN] eau souterraine [Termes IGN] géomorphologie locale [Termes IGN] Karnataka (Inde) [Termes IGN] lithologie [Termes IGN] occupation du sol [Termes IGN] potentiel hydrogène [Termes IGN] précipitation [Termes IGN] résistivité [Termes IGN] système d'information géographique [Termes IGN] utilisation du sol Résumé : (auteur) Electrical resistivity method and RS & GIS techniques are very much useful in identification of potential aquifer zones for exploitation, management and recharge of groundwater. Vertical Electrical Soundings are conducted at 35 locations in Gurpur watershed using Schlumberger array. The thematic layers like porosity, transmissivity and hydraulic conductivity are prepared using electrical resistivity data. Total of 13 thematic layers are used for vector integration and identification of Groundwater Potential Zones (GWPZ). The numerical weights and ranks are assigned to the themes based on their relationship with groundwater. The findings shows that the depth to bedrock varies from 9.1 to 44.4 m and most of the mid land and low land region shows moderate to high depths of about 25–44 m. The GWPZ are classified into five classes namely, Very Good (≈21.02 km2), Good (≈231.35 km2), Moderate (≈420.76 km2), Poor (≈185.05 km2) and Very Poor (≈19.56 km2). The Good and Moderate categories cover ≈75% of total area. Numéro de notice : A2021-483 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2019.1624986 Date de publication en ligne : 11/06/2019 En ligne : https://doi.org/10.1080/10106049.2019.1624986 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97442 [article]