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Spatial sampling uncertainty in SMEX04 soil moisture fields: a data-based resampling experiment / M. Gebremichael in Remote sensing of environment, vol 112 n° 2 (15/02/2008)  

Public [article]  inRemote sensing of environment > vol 112 n° 2 (15/02/2008) . - pp 326 - 336 Titre : Spatial sampling uncertainty in SMEX04 soil moisture fields: a data-based resampling experiment Type de document : Article/Communication Auteurs : M. Gebremichael, Auteur ; E.R. Vivoni, Auteur Année de publication : 2008 Article en page(s) : pp 326 - 336 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] échantillonnage d'image [Termes IGN] humidité du sol [Termes IGN] image aérienne [Termes IGN] image radar [Termes IGN] incertitude des données [Termes IGN] Mexico (Mexique) [Termes IGN] Soil Moisture Experiment Résumé : (Auteur) A data-based resampling experiment is performed to estimate sampling errors of area-averaged soil moisture estimates due to spatial sampling by ground-based sensors. The data consists of high-resolution soil moisture images derived from the Polarimetric Scanning Radiometer (PSR/CX) sensor flown on an aircraft as part of the summer field experiment (SMEX04 — Soil Moisture Experiment 2004) in the monsoon region of Sonora, Mexico. The sampling characteristics are investigated by accounting for random networks and evenly spaced networks. For random network designs, we develop a simple model that can be used to estimate the sampling uncertainty (expressed as standard deviation of sampling error as a percentage of the areal mean soil moisture) as a function of the number of sensors, mean soil moisture content and averaging area. This model is valid for five or more sensors. The model should prove useful to those wishing to assess the area-averaged performance of a soil moisture network. Furthermore, the method of analysis is applicable to other study regions (Oklahoma, Iowa, Alabama, Georgia, and Arizona) where soil moisture fields have been mapped at high resolution using airborne passive microwave remote sensors. Copyright Elsevier Numéro de notice : A2008-035 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2006.12.021 En ligne : https://doi.org/10.1016/j.rse.2006.12.021 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29030 [article]

Embedding landscape processes into triangulated terrain models / E.R. Vivoni in International journal of geographical information science IJGIS, vol 19 n° 4 (april 2005)  

Public [article]  inInternational journal of geographical information science IJGIS > vol 19 n° 4 (april 2005) . - pp 429 - 457 Titre : Embedding landscape processes into triangulated terrain models Type de document : Article/Communication Auteurs : E.R. Vivoni, Auteur ; V. Teles, Auteur ; V.Y. Ivanov, Auteur ; R.L. Bras, Auteur ; Dara Entekhabi, Auteur Année de publication : 2005 Article en page(s) : pp 429 - 457 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications SIG [Termes IGN] bassin hydrographique [Termes IGN] discrétisation spatiale [Termes IGN] érosion hydrique [Termes IGN] géomorphologie [Termes IGN] modèle de simulation [Termes IGN] pente [Termes IGN] prédiction [Termes IGN] ruissellement [Termes IGN] simulation [Termes IGN] système d'information géographique [Termes IGN] topographie [Termes IGN] Triangulated Irregular Network [Termes IGN] triangulation locale Résumé : (Auteur) Triangulated irregular networks (TIN) can form the basis for multiple-resolution representations in distributed hydrogeomorphic simulations over complex basins. Current methods for deriving TIN meshes depend primarily on surface slope without considering other terrain attributes significant to the watershed response such as the specific basin area. As an alternative, we present a methodology for combining a hydrogeomorphic or landscape index with an unstructured triangulated mesh. Landscape indices provide a concise method for describing steady-state terrain processes by isolating the dominant physical factors. The mesh-generation algorithm results in an adaptive discretization that resembles the spatial pattern of the landscape index with a high resolution retained in areas expected to impact the basin response. We compare the proposed algorithm with a slope-preserving method as a means for initializing the terrain representation in two TIN-based hydrogeomorphic models. Through three case studies in saturation-excess runoff, transport-limited soil erosion and shallow landslide simulation, we assess the distributed model sensitivity to the triangulated terrain algorithm. Model comparisons reveal that the process-based triangulations focus the distributed simulation in regions anticipated via a steady-state index to affect the transient watershed response. Numéro de notice : A2005-098 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article DOI : 10.1080/13658810512331325111 En ligne : https://doi.org/10.1080/13658810512331325111 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=27236 [article]

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079-05041	RAB	Revue	Centre de documentation	En réserve L003	Disponible
079-05042	RAB	Revue	Centre de documentation	En réserve L003	Disponible