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Landscape connectivity and insect herbivory: A framework for understanding tradeoffs among ecosystem services / Dorothy Y. Maguire in Global ecology and conservation, vol 4 (July 2015)
[article]
Titre : Landscape connectivity and insect herbivory: A framework for understanding tradeoffs among ecosystem services Type de document : Article/Communication Auteurs : Dorothy Y. Maguire, Auteur ; Patrick M.A. James, Auteur ; Christopher M. Buddle, Auteur ; Elena M. Bennett, Auteur Année de publication : 2015 Article en page(s) : pp 73 - 84 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] connexité (topologie)
[Termes IGN] corridor biologique
[Termes IGN] insecte nuisible
[Termes IGN] protection de l'environnement
[Termes IGN] service écosystémique
[Vedettes matières IGN] Ecologie forestièreRésumé : (auteur) Current theory suggests that ecosystem services in fragmented landscapes can be maintained by preserving connectivity of remaining habitat patches. However connectivity does not always influence services positively. For example, outbreaks of destructive insect herbivores can be facilitated by connectivity among forest patches. Understanding the positive and negative effects of connectivity on ecosystem processes is needed to help scientists and managers anticipate tradeoffs among services that result from forest fragmentation or restoration. In this paper we use a vote counting meta-analytic approach in combination with a literature survey to explore how connectivity affects ecosystem service provisioning using insect herbivory as a model process. Our results indicate that landscape connectivity affects herbivory in diverse ways, and that implications for services depend on whether we consider outbreaking species. Under non-outbreak conditions, herbivory positively affects services such as timber production, soil formation, and recreation by stimulating tree growth and enhancing soil productivity, but under outbreak conditions, herbivory negatively affects services by reducing timber yields and the aesthetic value of forests. We present a framework that shows herbivory is an important mechanism through which connectivity affects ecosystem services. Using case studies we demonstrate the applicability of the framework to management of two forest insect pests: the mountain pine beetle and forest tent caterpillar. Numéro de notice : A2015--046 Affiliation des auteurs : non IGN Thématique : BIODIVERSITE/FORET Nature : Article DOI : 10.1016/j.gecco.2015.05.006 En ligne : http://dx.doi.org/10.1016/j.gecco.2015.05.006 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=82113
in Global ecology and conservation > vol 4 (July 2015) . - pp 73 - 84[article]Geospatial analysis of urban landscape patterns in three major cities of Southeast Asia / Ronald C. Estoque in Tsukuba geoenvironmental sciences, vol 10 (december 2014)
[article]
Titre : Geospatial analysis of urban landscape patterns in three major cities of Southeast Asia Type de document : Article/Communication Auteurs : Ronald C. Estoque, Auteur ; Yuji Murayama, Auteur ; Courage Kamusoko, Auteur ; Akio Yamashita, Auteur Année de publication : 2014 Article en page(s) : pp 3 - 10 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse comparative
[Termes IGN] Bangkok (Thaïlande)
[Termes IGN] connexité (topologie)
[Termes IGN] densité
[Termes IGN] image Landsat
[Termes IGN] Jakarta (Indonésie)
[Termes IGN] Manille (Philippines)
[Termes IGN] paysage urbain
[Termes IGN] plan de déplacement urbain
[Termes IGN] urbanisation
[Termes IGN] utilisation du solRésumé : (auteur) Using a geospatial approach that integrates gradient analysis and landscape metrics, this study examines and compares the urban landscape patterns of three major cities of Southeast Asia, namely Bangkok, Jakarta, and Manila. Landsat-8 imageries for 2013 and 2014 were used to classify the urban land-use/cover of the three cities. Furthermore, various class-level landscape metrics were computed to facilitate spatial analysis. The results reveal that the proportional extent or density and physical connectedness of built-up lands in the three cities are inversely related to the gradient of the distance from the city center. In contrast, the fragmentation of built-up lands is directly related to the gradient of the distance from the city center. In the comparison of the three cities, the density of the urban development of Manila is relatively higher than that of Bangkok, but more especially that of Jakarta. The urban landscape of Jakarta is relatively more fragmented or dispersed than that of Bangkok, but more especially that of Manila. In terms of physical connectedness, Manila’s urban landscape is relatively more aggregated than that of Bangkok, but more especially that of Jakarta. The study results show that the gradient analysis and landscape metrics integrated approach can be used to examine and compare the spatial patterns of various complex urban landscapes. Numéro de notice : 15895 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : sans En ligne : http://hdl.handle.net/2241/00123143 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=79051
in Tsukuba geoenvironmental sciences > vol 10 (december 2014) . - pp 3 - 10[article]Documents numériques
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15895-Geospatial analysis of urban landscape patternsAdobe Acrobat PDF A shape-based segmentation method for mobile laser scanning point clouds / Yang Bisheng in ISPRS Journal of photogrammetry and remote sensing, vol 81 (July 2013)
[article]
Titre : A shape-based segmentation method for mobile laser scanning point clouds Type de document : Article/Communication Auteurs : Yang Bisheng, Auteur ; Zhen Dong, Auteur Année de publication : 2013 Article en page(s) : pp 19 - 30 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Lasergrammétrie
[Termes IGN] classification par séparateurs à vaste marge
[Termes IGN] connexité (topologie)
[Termes IGN] données lidar
[Termes IGN] données localisées 3D
[Termes IGN] segmentation
[Termes IGN] semis de points
[Termes IGN] traitement automatique de donnéesRésumé : (Auteur) Segmentation of mobile laser point clouds of urban scenes into objects is an important step for post-processing (e.g., interpretation) of point clouds. Point clouds of urban scenes contain numerous objects with significant size variability, complex and incomplete structures, and holes or variable point densities, raising great challenges for the segmentation of mobile laser point clouds. This paper addresses these challenges by proposing a shape-based segmentation method. The proposed method first calculates the optimal neighborhood size of each point to derive the geometric features associated with it, and then classifies the point clouds according to geometric features using support vector machines (SVMs). Second, a set of rules are defined to segment the classified point clouds, and a similarity criterion for segments is proposed to overcome over-segmentation. Finally, the segmentation output is merged based on topological connectivity into a meaningful geometrical abstraction. The proposed method has been tested on point clouds of two urban scenes obtained by different mobile laser scanners. The results show that the proposed method segments large-scale mobile laser point clouds with good accuracy and computationally effective time cost, and that it segments pole-like objects particularly well. Numéro de notice : A2013-386 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.isprsjprs.2013.04.002 En ligne : https://doi.org/10.1016/j.isprsjprs.2013.04.002 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32524
in ISPRS Journal of photogrammetry and remote sensing > vol 81 (July 2013) . - pp 19 - 30[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 081-2013071 RAB Revue Centre de documentation En réserve L003 Disponible Topological gradient connection analysis for feature detection / Chao-Yuan Lo in Photogrammetric record, vol 28 n° 141 (March - May 2013)
[article]
Titre : Topological gradient connection analysis for feature detection Type de document : Article/Communication Auteurs : Chao-Yuan Lo, Auteur ; Lieng-Chien Chen, Auteur Année de publication : 2013 Article en page(s) : pp 7 - 26 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique
[Termes IGN] analyse comparative
[Termes IGN] connexité (topologie)
[Termes IGN] détection de contours
[Termes IGN] extraction de traits caractéristiques
[Termes IGN] filtre de Canny
[Termes IGN] gradient
[Termes IGN] ligne caractéristique
[Termes IGN] lissage de courbe
[Termes IGN] niveau de gris (image)
[Termes IGN] relation topologiqueRésumé : (Auteur) Edges and corners are two major image features in the modelling of man-made objects; an edge provides strong geometric orientation and corners possess good localisation. Feature detection is the basis of image processing for numerous applications such as image registration and object modelling. Completeness and localisation are the two major considerations for these applications; however, illumination, reflectance and shadows may interfere with image grey values to produce various gradients along an edge. Thus, threshold selection is an important step in obtaining suitable features in target-dependent methods as improper selection might cause information loss and broken edges. Instead of threshold selection, this study therefore proposes a feature extraction method using topological gradient connection (TGC) analysis involving three steps: grey value refinement, gradient computation and topological connection analysis. The first step uses a Gaussian filter to smooth the grey value image. The second step computes directional gradients to identify ridge pixels and collect feature candidates. The third step analyses adjacent candidates based on the criterion of topological connection. This three-step tracing procedure combines these connected candidates into a single object. The proposed scheme employs different images derived from various sensors and compares them with the Canny operator (using manually selected thresholds) and manually plotted corners for detection ability assessment. Experimental results indicate that the automatic results are more complete for subtle feature lines than the Canny edges. In addition, the proposed method provides higher flexibility in selecting suitable feature layers for different applications. Numéro de notice : A2013-149 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1111/j.1477-9730.2012.00703.x Date de publication en ligne : 16/12/2012 En ligne : https://doi.org/10.1111/j.1477-9730.2012.00703.x Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32287
in Photogrammetric record > vol 28 n° 141 (March - May 2013) . - pp 7 - 26[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 106-2013011 RAB Revue Centre de documentation En réserve L003 Disponible Automatic and accurate extraction of road intersections from raster maps / Yao-Yi Chiang in Geoinformatica, vol 13 n° 2 (June 2009)
[article]
Titre : Automatic and accurate extraction of road intersections from raster maps Type de document : Article/Communication Auteurs : Yao-Yi Chiang, Auteur ; C. Shahabi, Auteur ; Craig A. Knoblock, Auteur ; C.C. Chen, Auteur Année de publication : 2009 Article en page(s) : pp 121 - 157 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image
[Termes IGN] carrefour
[Termes IGN] carte numérique
[Termes IGN] conflation
[Termes IGN] connexité (topologie)
[Termes IGN] données maillées
[Termes IGN] extraction automatique
[Termes IGN] extraction du réseau routier
[Termes IGN] intégration de données
[Termes IGN] réseau routierRésumé : (Auteur) Since maps are widely available for many areas around the globe, they provide a valuable resource to help understand other geospatial sources such as to identify roads or to annotate buildings in imagery. To utilize the maps for understanding other geospatial sources, one of the most valuable types of information we need from the map is the road network, because the roads are common features used across different geospatial data sets. Specifically, the set of road intersections of the map provides key information about the road network, which includes the location of the road junctions, the number of roads that meet at the intersections (i.e., connectivity), and the orientations of these roads. The set of road intersections helps to identify roads on imagery by serving as initial seed templates to locate road pixels. Moreover, a conflation system can use the road intersections as reference features (i.e., control point set) to align the map with other geospatial sources, such as aerial imagery or vector data. In this paper, we present a framework for automatically and accurately extracting road intersections from raster maps. Identifying the road intersections is difficult because raster maps typically contain much information such as roads, symbols, characters, or even contour lines. We combine a variety of image processing and graphics recognition methods to automatically separate roads from the raster map and then extract the road intersections. The extracted information includes a set of road intersection positions, the road connectivity, and road orientations. For the problem of road intersection extraction, our approach achieves over 95% precision (correctness) with over 75% recall (completeness) on average on a set of 70 raster maps from a variety of sources. Copyright Springer Numéro de notice : A2009-073 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1007/s10707-008-0046-3 En ligne : https://doi.org/10.1007/s10707-008-0046-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29703
in Geoinformatica > vol 13 n° 2 (June 2009) . - pp 121 - 157[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 057-09021 RAB Revue Centre de documentation En réserve L003 Disponible Indexing network-constrained trajectories for connectivity-based queries / X. Li in International journal of geographical information science IJGIS, vol 20 n° 3 (march 2006)PermalinkCodage, adaptation et comparaison d'agorithmes de squelettisation d'une surface sur le SIG LAMPS2 / Christophe Mangeat (2005)PermalinkMesure de la connectivité du paysage à travers un maillage spatial / Jean-Christophe Foltête in Revue internationale de géomatique, vol 14 n° 1 (mars - mai 2004)PermalinkAnalyse descriptive multi-échelle de la structure d'un paysage : application à la mosaïque d'occupation du sol d'un territoire agricole dans le bocage breton / Nicolas Schermann in Revue internationale de géomatique, vol 12 n° 2 (juin - août 2002)PermalinkLecture automatique de cartes, 1. Thèse / Marc Pierrot-Deseilligny (1994)Permalink