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Classification of tree species in a heterogeneous urban environment using object-based ensemble analysis and World View-2 satellite imagery / Simbarashe Jombo in Applied geomatics, vol 13 n° 3 (September 2021)  

Public [article]  inApplied geomatics > vol 13 n° 3 (September 2021) . - pp 373 - 387 Titre : Classification of tree species in a heterogeneous urban environment using object-based ensemble analysis and World View-2 satellite imagery Type de document : Article/Communication Auteurs : Simbarashe Jombo, Auteur ; Elhadi Adam, Auteur ; John Odindi, Auteur Année de publication : 2021 Article en page(s) : pp 373 - 387 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image optique [Termes IGN] analyse d'image orientée objet [Termes IGN] arbre urbain [Termes IGN] classification par forêts aléatoires [Termes IGN] classification par séparateurs à vaste marge [Termes IGN] espèce végétale [Termes IGN] image à très haute résolution [Termes IGN] image multibande [Termes IGN] image Worldview [Termes IGN] indice de végétation [Termes IGN] Johannesbourg [Termes IGN] segmentation d'image Résumé : (auteur) Urban trees are valuable in, inter alia, ameliorating air pollution and mitigating the effects associated with urban heat islands. The dearth of tree cover maps is a major challenge for urban planners in the management of urban trees. This work adopts remote sensing approaches to provide urban tree cover maps which can strengthen urban landscape management. Whereas traditional pixel-based classification approaches have been commonly used in image classification, they are not well-suited for urban tree mapping due to their failure to fully explore the image’s spatial and spectral characteristics. Object-based classification techniques produce improved accuracies using additional variables. This study depicts the capability of object-based image analysis (OBIA) in mapping common urban trees using very high-resolution (VHR) WorldView-2 (WV-2) imagery. The study tests the utility of WV-2 bands and other feature variables in the object-based mapping of common urban trees and other land cover classes. Furthermore, the study compares the utility of Support Vector Machine (SVM) and Random Forest (RF) in the object-based mapping of common urban trees and other land cover classes. The results show that the Normalized Difference Vegetation Index (NDVI), NIR 1 and NIR 2 bands were important in the classification of common urban trees and other land cover classes. The RF classifier performed better than SVM, with an overall accuracy of 91.9% as compared to 87.3% for SVM. The results of this study offer insight to urban authorities with knowledge on the segmentation parameters, classification methods and feature variables for mapping urban trees, valuable in urban tree management. Numéro de notice : A2021-624 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article DOI : 10.1007/s12518-021-00358-3 date de publication en ligne : 20/01/2021 En ligne : https://doi.org/10.1007/s12518-021-00358-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98248 [article]

Examining the effectiveness of Sentinel-1 and 2 imagery for commercial forest species mapping / Mthembeni Mngadi in Geocarto international, vol 36 n° 1 ([01/01/2021])  

Public [article]  inGeocarto international > vol 36 n° 1 [01/01/2021] . - pp 1 - 12 Titre : Examining the effectiveness of Sentinel-1 and 2 imagery for commercial forest species mapping Type de document : Article/Communication Auteurs : Mthembeni Mngadi, Auteur ; John Odindi, Auteur ; Kabir Peerbhay, Auteur ; Onisimo Mutanga, Auteur Année de publication : 2021 Article en page(s) : pp 1 - 12 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image mixte [Termes IGN] analyse discriminante [Termes IGN] carte forestière [Termes IGN] Eucalyptus (genre) [Termes IGN] image Sentinel-MSI [Termes IGN] image Sentinel-SAR [Termes IGN] KwaZulu-Natal (Afrique du Sud) [Termes IGN] Pinus (genre) [Termes IGN] télédétection spatiale Résumé : (Auteur) The successful launch and operation of the Sentinel satellite platform has provided access to freely available remotely sensed data useful for commercial forest species discrimination. Sentinel – 1 (S1) with a synthetic aperture radar (SAR) sensor and Sentinel – 2 (S2) multi-spectral sensor with additional and strategically positioned bands offer great potential for providing reliable information for discriminating and mapping commercial forest species. In this study, we sought to determine the value of S1 and S2 data characteristics in discriminating and mapping commercial forest species. Using linear discriminant analysis (LDA) algorithm, S2 multi-spectral imagery showed an overall classification accuracy of 84% (kappa = 0.81), with bands such as the red-edge (703.9–740.2 nm), narrow near infrared (835.1–864.8 nm), and short wave infrared (1613.7–2202.4 nm) particularly influential in discriminating individual forest species stands. When Sentinel 2’s spectral wavebands were fused with Sentinel 1’s (SAR) VV and VH polarimetric modes, overall classification accuracies improved to 87% (kappa = 0.83) and 88% (kappa = 0.85), respectively. These findings demonstrate the value of combining Sentinel’s multispectral and SAR structural information characteristics in improving commercial forest species discrimination. These, in addition to the sensors free availability, higher spatial resolution and larger swath width, offer unprecedented opportunities for improved local and large scale commercial forest species discrimination and mapping. Numéro de notice : A2021-050 Affiliation des auteurs : non IGN Thématique : FORET/IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2019.1585483 date de publication en ligne : 10/06/2019 En ligne : https://doi.org/10.1080/10106049.2019.1585483 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96719 [article]

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Modeling the risk of robbery in the city of Tshwane, South Africa / Nicolas Kemp in Cartography and Geographic Information Science, vol 48 n° 1 (January 2021)  

Public [article]  inCartography and Geographic Information Science > vol 48 n° 1 (January 2021) . - pp 29 - 42 Titre : Modeling the risk of robbery in the city of Tshwane, South Africa Type de document : Article/Communication Auteurs : Nicolas Kemp, Auteur ; Gregory D. Breetzke, Auteur ; Anthony Cooper, Auteur Année de publication : 2021 Article en page(s) : pp 29 - 42 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Analyse spatiale [Termes IGN] Afrique du sud (état) [Termes IGN] criminalité [Termes IGN] modèle de simulation [Termes IGN] modélisation spatiale [Termes IGN] prévention des risques [Termes IGN] sécurité civile [Termes IGN] zone à risque Résumé : (auteur) In this study, we model the risk of robbery in the City of Tshwane in South Africa. We use the collective knowledge of two prominent spatial theories of crime (social disorganization theory, and crime pattern theory) to guide the selection of data and employ rudimentary geospatial techniques to create a crude model that identifies the risk of future robbery incidents in the city. The model is validated using actual robbery incidences recorded for the city. Overall the model performs reasonably well with approximately 70% of future robbery incidences accurately identified within a small subset of the overall model. Developing countries such as South Africa are in dire need of crime risk intensity models that are simple, and not data intensive to allocate scarce crime prevention resources in a more optimal fashion. It is anticipated that this model is a first step in this regard. Numéro de notice : A2021-017 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/15230406.2020.1814872 date de publication en ligne : 10/09/2020 En ligne : https://doi.org/10.1080/15230406.2020.1814872 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96455 [article]

Strategic and Acupunctural GIS Implementation within Community-Oriented Organizations: Evidence-Based Insights from a South African Participatory Action Research for Informal Settlement Upgrading / Jennifer Barella in Cartographica, vol 55 n° 4 (Winter 2020)  

Public [article]  inCartographica > vol 55 n° 4 (Winter 2020) . - pp 266 - 280 Titre : Strategic and Acupunctural GIS Implementation within Community-Oriented Organizations: Evidence-Based Insights from a South African Participatory Action Research for Informal Settlement Upgrading Type de document : Article/Communication Auteurs : Jennifer Barella, Auteur Année de publication : 2020 Article en page(s) : pp 266 - 280 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Systèmes d'information géographique [Termes IGN] Cape Town [Termes IGN] organisation non gouvernementale [Termes IGN] outil d'aide à la décision [Termes IGN] recensement [Termes IGN] SIG participatif Résumé : (Auteur) This article brings evidence-based insights to support the importance of considering contextual elements when analyzing modalities of GIS implementation within NGOs and community-based organizations. I discuss challenges and unforeseen insights of GIS implementation within an advocacy NGO that supports community claims in an informal settlement of Cape Town’s metropolitan area. Through the lens of empirical data, limitations of the GIS implementation models framework are highlighted. GIS implementation will appear to be “acupunctural” and highly strategic and will unveil the use of GIS-based solutions as relational leverage. Finally, I discuss directions for further scientific research on GIS implementation within NGOs and community-based organizations. Numéro de notice : A2020-776 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.3138/cart-2020-0013 date de publication en ligne : 22/12/2020 En ligne : https://doi.org/10.3138/cart-2020-0013 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96691 [article]

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Emplaced distances / Giovanni Spissu in Cartographic journal (the), Vol 57 n° 3 (August 2020)  

Public [article]  inCartographic journal (the) > Vol 57 n° 3 (August 2020) . - pp 261 - 272 Titre : Emplaced distances Type de document : Article/Communication Auteurs : Giovanni Spissu, Auteur Année de publication : 2020 Article en page(s) : pp 261 - 272 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Rédaction cartographique [Termes IGN] art [Termes IGN] Cape Town [Termes IGN] carte profonde [Termes IGN] esthétique [Termes IGN] ethnographie [Termes IGN] représentation cartographique [Termes IGN] Sardaigne [Termes IGN] territoire Résumé : (auteur) In the Sardinian artist’s Maria Lai’s works, Geografie and Geogafie Spaziali, she depicted the cosmic pathways of the Sardus Pater, using a cartographic representation of one of the island’s most popular legends. One of these works’ key features is the use of embroidery techniques learned from women of her village. She considers the Sardinian territory not only an object of representation but as an expressive medium of her work and a fertile space that generates new worlds. I argue that we can draw on Maria Lai’s work to conceive a particular form of deep mapping through which to explore the territory through its imaginative dimension. For the purpose of this article, I intend to describe how, inspired by Lai’s works, I built Emplaced Distance, a map of Cape Town through the Sardinian territory. Numéro de notice : A2020-806 Affiliation des auteurs : non IGN Thématique : GEOMATIQUE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/00087041.2019.1631006 date de publication en ligne : 21/01/2020 En ligne : https://doi.org/10.1080/00087041.2019.1631006 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96763 [article]

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Near-real time forecasting and change detection for an open ecosystem with complex natural dynamics / Jasper A. Slingsby in ISPRS Journal of photogrammetry and remote sensing, vol 166 (August 2020)  

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Towards a semi-automated mapping of Australia native invasive alien Acacia trees using Sentinel-2 and radiative transfer models in South Africa / Cecilia Masemola in ISPRS Journal of photogrammetry and remote sensing, vol 166 (August 2020)  

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2014 Hartebeesthoek co-location survey reprocessing report / Jean-Michaël Muller (2020)

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Evaluating the potential of the red edge channel for C3 (Festuca spp.) grass discrimination using Sentinel-2 and Rapid Eye satellite image data / Charles Otunga in Geocarto international, vol 34 n° 10 ([15/07/2019])  

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Remote sensing of species diversity using Landsat 8 spectral variables / Sabelo Madonsela in ISPRS Journal of photogrammetry and remote sensing, vol 133 (November 2017)  

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Stand-volume estimation from multi-source data for coppiced and high forest Eucalyptus spp. silvicultural systems in KwaZulu-Natal, South Africa / Timothy Dube in ISPRS Journal of photogrammetry and remote sensing, vol 132 (October 2017)  

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Long-term soil moisture dynamics derived from GNSS interferometric reflectometry: a case study for Sutherland, South Africa / Sibylle Vey in GPS solutions, vol 20 n° 4 (October 2016)  

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The impact of integrating WorldView-2 sensor and environmental variables in estimating plantation forest species aboveground biomass and carbon stocks in uMgeni Catchment, South Africa / Timothy Dube in ISPRS Journal of photogrammetry and remote sensing, vol 119 (September 2016)  

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Optimizing the spatial resolution of WorldView-2 imagery for discriminating forest vegetation at subspecies level in KwaZulu-Natal, South Africa / Romano Lottering in Geocarto international, vol 31 n° 7 - 8 (July - August 2016)  

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Optimising the spatial resolution of WorldView-2 pan-sharpened imagery for predicting levels of Gonipterus scutellatus defoliation in KwaZulu-Natal, South Africa / Romano Lottering in ISPRS Journal of photogrammetry and remote sensing, vol 112 (February 2016)  

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