{"id":5299,"date":"2014-06-24T11:40:47","date_gmt":"2014-06-24T11:40:47","guid":{"rendered":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/?page_id=5299"},"modified":"2015-12-08T13:29:29","modified_gmt":"2015-12-08T13:29:29","slug":"digital-fra","status":"publish","type":"page","link":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/?page_id=5299","title":{"rendered":"Digital-FRA"},"content":{"rendered":"<p><a href=\"https:\/\/mycor.iam.inrae.fr\/ARBRE\/wp-content\/uploads\/2014\/06\/digital-fr.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-8733\" src=\"https:\/\/mycor.iam.inrae.fr\/ARBRE\/wp-content\/uploads\/2014\/06\/digital-fr.png\" alt=\"digital fr\" width=\"747\" height=\"249\" \/><\/a><\/p>\n<p><strong>Use of digital canopy height models to improve forest resource assessments at\u00a0 local and regional levels. <\/strong><\/p>\n<p><em>Responsable scientifique\u00a0<\/em>: Jean-Pierre Renaud (ONF &#8211; P\u00f4le R&amp;D de Nancy)<\/p>\n<p><em>Partenaires Labex\u00a0:<\/em> L. St-Andr\u00e9 (BEF), F. Ningre (LERFoB)<\/p>\n<p><em>Collaboration\u00a0: Jean-Christophe Herv\u00e9 &amp; C\u00e9dric V\u00e9ga (LIF, IGN); Marc Pierrot-Deseilligny (ENSG, IGN)\u00a0; Philippe Lejeune &amp; Jonathan Lisein (Univ. Li\u00e8ge-Gembloux)\u00a0; Nicolas Barbier (IRD, UMR AMAP)\u00a0; S\u00e9bastien Conil (OPE, ANDRA)\u00a0; Anne Jolly, J\u00e9r\u00f4me Bock &amp; Alain Munoz (ONF)<\/em><\/p>\n<p>____________________________<\/p>\n<p><strong><em>Contexte<\/em><\/strong>\u2014 Les r\u00e9cents d\u00e9veloppements dans le domaine du LiDAR a\u00e9roport\u00e9 \u00e0 balayage offrent de nouvelles possibilit\u00e9s pour estimer et cartographier diff\u00e9rents attributs forestiers et am\u00e9liorer la pr\u00e9cision des inventaires.<\/p>\n<p><strong><em>Objectifs<\/em><\/strong>\u2014 Dans cette \u00e9tude, deux m\u00e9thodes de segmentation des nuages de points LiDAR ont \u00e9t\u00e9 utilis\u00e9es afin d\u2019obtenir de nouvelles variables et d\u2019\u00e9valuer leur apport sur la pr\u00e9cision d\u2019estimation de la hauteur dominante, de la surface terri\u00e8re et du volume, sur trois sites forestiers contrast\u00e9s.<\/p>\n<p><strong><em>D\u00e9marche<\/em><\/strong>\u2014 L\u2019originalit\u00e9 de cette approche vient de l\u2019utilisation conjointe de variables de segmentation et de m\u00e9triques standards de distribution de hauteur dans le cadre d\u2019une approche \u00ab\u00a0placette\u00a0\u00bb. Les pr\u00e9cisions obtenues \u00e0 l\u2019aide des variables de segmentation ont \u00e9t\u00e9 compar\u00e9es \u00e0 celles obtenues par l\u2019approche \u00ab\u00a0placette\u00a0\u00bb initialement propos\u00e9e par N\u00e6sset (1997) (un pionnier dans le domaine).<\/p>\n<p><strong><em>R\u00e9sultats et impacts attendus <\/em><\/strong>\u2014 Cette approche novatrice permettra d\u2019am\u00e9liorer les mod\u00e8les pr\u00e9dictifs de variables dendrom\u00e9triques \u00e0 partir de donn\u00e9es de t\u00e9l\u00e9d\u00e9tection et facilitera l\u2019\u00e9valuation de la ressource \u00e0 des \u00e9chelles plus locales. Elle ouvre \u00e9galement des perspectives nouvelles pour alimenter les mod\u00e8les de dynamique foresti\u00e8re.<\/p>\n<p><strong><em>R\u00e9sultats marquants<\/em> <\/strong>\u2014<\/p>\n<p>Les r\u00e9sultats confirment l\u2019avantage de combiner les 2 m\u00e9thodes.<\/p>\n<ul>\n<li>Pour la surface terri\u00e8re et le volume, des R\u00b2 de 0.92 et 0.95, et une erreur quadratique moyenne de 4.6 m\u00b2\/ha <em>(16%)<\/em> et 72.4 m\u00b3\/ha <em>(17%) <\/em>ont \u00e9t\u00e9 respectivement obtenus.<\/li>\n<li>Pour la hauteur dominante, l\u2019erreur du mod\u00e8le avoisine l\u2019erreur de mesure sur le terrain (estim\u00e9e inf\u00e9rieure \u00e0 1 m).<\/li>\n<\/ul>\n<p><em><strong>Principales conclusions<\/strong>\u00a0 <\/em>\u2014 Il semble donc que l\u2019int\u00e9gration de variables issues de la segmentation de houppiers permette d\u2019am\u00e9liorer l\u2019estimation des attributs forestiers. La robustesse de ces r\u00e9sultats reste \u00e0 \u00e9valuer sur un plus grand nombre de peuplements et sur des configurations d\u2019acquisition LiDAR vari\u00e9es.<\/p>\n<p><strong><em>Perspectives<\/em><\/strong> \u2014 Cette \u00e9tude ouvre des perspectives int\u00e9ressantes sur l\u2019utilisation de MNH pour estimer les attributs forestiers, notamment, elle permet d\u2019envisager l\u2019utilisation de MNH photogramm\u00e9triques issus de photos a\u00e9riennes de l\u2019IGN, r\u00e9guli\u00e8rement disponibles (\u00e0 tous les 3 \u00e0 5 ans) sur tout le territoire m\u00e9tropolitain.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Use of digital canopy height models to improve forest resource assessments at\u00a0 local and regional levels. Responsable scientifique\u00a0: Jean-Pierre Renaud (ONF &#8211; P\u00f4le R&amp;D de Nancy) Partenaires Labex\u00a0: L. St-Andr\u00e9 (BEF), F. Ningre (LERFoB) Collaboration\u00a0: Jean-Christophe Herv\u00e9 &amp; C\u00e9dric V\u00e9ga &hellip; <a href=\"https:\/\/mycor.iam.inrae.fr\/ARBRE\/?page_id=5299\">Continuer la lecture <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"parent":2122,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"footnotes":""},"class_list":["post-5299","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=\/wp\/v2\/pages\/5299","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5299"}],"version-history":[{"count":0,"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=\/wp\/v2\/pages\/5299\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=\/wp\/v2\/pages\/2122"}],"wp:attachment":[{"href":"https:\/\/mycor.iam.inrae.fr\/ARBRE\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5299"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}