﻿{"id":14101,"date":"2025-06-19T10:00:00","date_gmt":"2025-06-19T08:00:00","guid":{"rendered":"https:\/\/www.sigterritoires.fr\/?p=14101"},"modified":"2025-06-14T12:02:35","modified_gmt":"2025-06-14T10:02:35","slug":"heatmaps-et-cartes-de-hotspots-dans-qgis","status":"publish","type":"post","link":"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/","title":{"rendered":"Heatmaps et cartes de hotspots dans QGIS"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Heatmaps_et_cartes_de_hotspots_dans_QGIS_comprendre_les_differences\"><\/span>Heatmaps et cartes de hotspots dans QGIS : comprendre les diff\u00e9rences<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>En analyse spatiale, les <strong>heatmaps<\/strong> (ou cartes de chaleur) et les <strong>cartes de hotspots<\/strong> sont deux techniques puissantes pour r\u00e9v\u00e9ler des concentrations ou des zones d\u2019int\u00e9r\u00eat \u00e0 partir de donn\u00e9es g\u00e9ographiques. Si leur apparence peut \u00eatre similaire \u2014 zones color\u00e9es sugg\u00e9rant des densit\u00e9s ou des points chauds \u2014 elles reposent pourtant sur des logiques diff\u00e9rentes et servent des objectifs distincts.<\/p>\n\n\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 counter-hierarchy ez-toc-counter ez-toc-light-blue ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Contenu <\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Heatmaps_et_cartes_de_hotspots_dans_QGIS_comprendre_les_differences\" >Heatmaps et cartes de hotspots dans QGIS : comprendre les diff\u00e9rences<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Heatmaps_visualiser_la_densite_brute\" >Heatmaps : visualiser la densit\u00e9 brute<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Caracteristiques\" >Caract\u00e9ristiques :<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Cartes_de_hotspots_identifier_des_clusters_statistiquement_significatifs\" >Cartes de hotspots : identifier des clusters statistiquement significatifs<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Caracteristiques-2\" >Caract\u00e9ristiques :<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Ressemblances_et_differences\" >Ressemblances et diff\u00e9rences<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-1'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Tutoriel_QGIS_%E2%80%93_Heatmaps_et_Hotspots\" >Tutoriel QGIS \u2013 Heatmaps et Hotspots<\/a><ul class='ez-toc-list-level-2' ><li class='ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#PARTIE_1_Creer_une_Heatmap_Carte_de_chaleur\" >PARTIE 1 : Cr\u00e9er une Heatmap (Carte de chaleur)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Objectif_Visualiser_la_densite_de_points_sous_forme_dun_raster_colore\" >Objectif : Visualiser la densit\u00e9 de points sous forme d\u2019un raster color\u00e9<\/a><ul class='ez-toc-list-level-4' ><li class='ez-toc-heading-level-4'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Etapes\" >\u00c9tapes :<\/a><\/li><\/ul><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#PARTIE_2_Creer_une_carte_de_Hotspots_concentrations_significatives\" >PARTIE 2 : Cr\u00e9er une carte de Hotspots (concentrations significatives)<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Objectif_Identifier_les_zones_ou_la_densite_de_points_est_significativement_elevee\" >Objectif : Identifier les zones o\u00f9 la densit\u00e9 de points est significativement \u00e9lev\u00e9e<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/#Methode_simple_agregation_calcul\" >M\u00e9thode simple (agr\u00e9gation + calcul)<\/a><\/li><\/ul><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Heatmaps_visualiser_la_densite_brute\"><\/span>Heatmaps : visualiser la densit\u00e9 brute<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Les heatmaps, g\u00e9n\u00e9r\u00e9es par l\u2019outil <em>Densit\u00e9 par noyau (Kernel Density Estimation)<\/em> dans QGIS, permettent de visualiser la <strong>densit\u00e9 de points<\/strong> dans un espace donn\u00e9. Elles ne tiennent pas compte des attributs des entit\u00e9s (\u00e0 moins d\u2019utiliser un champ de pond\u00e9ration), mais simplement de la proximit\u00e9 spatiale.<\/p>\n\n\n\n<p>Leur u<strong>tilisation typique<\/strong> est de visualiser o\u00f9 se concentrent des \u00e9v\u00e9nements comme des accidents de la route, des infractions ou des appels d\u2019urgence.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Caracteristiques\"><\/span><strong>Caract\u00e9ristiques<\/strong> :<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>R\u00e9sultat : raster continu (image) o\u00f9 chaque pixel repr\u00e9sente une densit\u00e9.<\/li>\n\n\n\n<li>Param\u00e8tres cl\u00e9s : rayon de recherche, taille du pixel, champ de pond\u00e9ration (facultatif).<\/li>\n\n\n\n<li>M\u00e9thode purement descriptive.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Cartes_de_hotspots_identifier_des_clusters_statistiquement_significatifs\"><\/span>Cartes de hotspots : identifier des clusters statistiquement significatifs<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Les cartes de hotspots, quant \u00e0 elles, s\u2019appuient sur une <strong>analyse statistique spatiale<\/strong> pour d\u00e9tecter des regroupements anormalement \u00e9lev\u00e9s (hotspots) ou faibles (coldspots) de valeurs. Dans QGIS, cela se fait via l\u2019outil <em>Cluster and Outlier Analysis (Anselin Local Moran\u2019s I)<\/em> ou en utilisant le plugin <em>Hotspot Analysis<\/em>.<\/p>\n\n\n\n<p>Leur u<strong>tilisation typique<\/strong> est d&rsquo;identifier des quartiers o\u00f9 les cambriolages sont significativement plus nombreux que dans les zones voisines.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Caracteristiques-2\"><\/span><strong>Caract\u00e9ristiques<\/strong> :<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>R\u00e9sultat : couche vectorielle ou raster avec typologie (hotspot, coldspot, non significatif).<\/li>\n\n\n\n<li>Requiert un champ de valeur (nombre de cas, taux, etc.).<\/li>\n\n\n\n<li>M\u00e9thode statistique \u2192 interpr\u00e9tation plus robuste, mais aussi plus exigeante.<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ressemblances_et_differences\"><\/span>Ressemblances et diff\u00e9rences<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>Crit\u00e8re<\/th><th>Heatmap<\/th><th>Carte de Hotspots<\/th><\/tr><\/thead><tbody><tr><td>Donn\u00e9es d&rsquo;entr\u00e9e<\/td><td>Points (ou \u00e9v\u00e9nements ponctuels)<\/td><td>Points ou polygones avec attributs<\/td><\/tr><tr><td>R\u00e9sultat<\/td><td>Raster de densit\u00e9<\/td><td>Carte th\u00e9matique (typologie)<\/td><\/tr><tr><td>M\u00e9thode<\/td><td>Descriptive<\/td><td>Statistique (cluster significatif)<\/td><\/tr><tr><td>Usage principal<\/td><td>Visualisation rapide<\/td><td>Analyse approfondie<\/td><\/tr><tr><td>Prise en compte des valeurs<\/td><td>Optionnelle (champ pond\u00e9r\u00e9)<\/td><td>Obligatoire (champ \u00e0 analyser)<\/td><\/tr><tr><td>Outils dans QGIS<\/td><td>Densit\u00e9 par noyau<\/td><td>Anselin Local Moran \/ Plugins<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>Voici un <strong>tutoriel pas \u00e0 pas<\/strong> pour cr\u00e9er une <strong>heatmap<\/strong> (carte de chaleur) et une <strong>carte de hotspots<\/strong> dans <strong>QGIS<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Tutoriel_QGIS_%E2%80%93_Heatmaps_et_Hotspots\"><\/span>Tutoriel QGIS \u2013 Heatmaps et Hotspots<span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"PARTIE_1_Creer_une_Heatmap_Carte_de_chaleur\"><\/span>PARTIE 1 : Cr\u00e9er une Heatmap (Carte de chaleur)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Objectif_Visualiser_la_densite_de_points_sous_forme_dun_raster_colore\"><\/span>Objectif : Visualiser la densit\u00e9 de points sous forme d\u2019un raster color\u00e9<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<h4 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Etapes\"><\/span>\u00c9tapes :<span class=\"ez-toc-section-end\"><\/span><\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Charger la couche de points<\/strong>\n<ul class=\"wp-block-list\">\n<li>Menu : <code>Couches &gt; Ajouter une couche &gt; Ajouter une couche vecteur<\/code><\/li>\n\n\n\n<li>Charger votre fichier contenant des points (ex. : ecoles.geojson)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Ouvrir l\u2019outil \u00ab\u00a0Cr\u00e9er une carte de chaleur\u00a0\u00bb<\/strong>\n<ul class=\"wp-block-list\">\n<li>Menu : <code>Traitements &gt; Bo\u00eete \u00e0 outils<\/code> &gt; Interpolation<\/li>\n\n\n\n<li>Rechercher <strong>\u00ab\u00a0Carte de chaleur (Estimation par noyau)\u00a0\u00bb<\/strong><\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Param\u00e9trer l\u2019outil<\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>Entr\u00e9e<\/strong> : votre couche de points<\/li>\n\n\n\n<li><strong>Champ de pond\u00e9ration<\/strong> : laisser vide ou choisir un champ si vos points ont une valeur (ex. nombre de signalements)<\/li>\n\n\n\n<li><strong>Type de noyau<\/strong> : <code>Quadratique<\/code> <\/li>\n\n\n\n<li><strong>Rayon de recherche<\/strong> :1500 m (\u00e0 adapter selon votre cas)<\/li>\n\n\n\n<li><strong>R\u00e9solution raster<\/strong> : 10 ou 20 m<\/li>\n\n\n\n<li><strong>Nom du fichier de sortie<\/strong> : heatmap.tif<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Lancer le traitement<\/strong><\/li>\n\n\n\n<li><strong>Styliser la heatmap<\/strong>\n<ul class=\"wp-block-list\">\n<li>Clic droit sur la couche raster &gt; <code>Propri\u00e9t\u00e9s &gt; Symbologie<\/code><\/li>\n\n\n\n<li><strong>Type de rendu<\/strong> : <code>Pseudo-couleur \u00e0 bande unique<\/code><\/li>\n\n\n\n<li>Choisir un <strong>d\u00e9grad\u00e9 de couleurs<\/strong> (<code>Reds<\/code>, <code>Viridis<\/code>, <code>Inferno<\/code>, etc.)<\/li>\n\n\n\n<li><strong>Interpolation <\/strong>: Lin\u00e9aire <\/li>\n\n\n\n<li>Ajuster les valeurs mini\/maxi si besoin<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<p><strong>R\u00e9sultat<\/strong> : une carte continue o\u00f9 les zones jaunes indiquent une forte densit\u00e9 de points.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"311\" data-attachment-id=\"14192\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/heatmap\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?fit=1664%2C810&amp;ssl=1\" data-orig-size=\"1664,810\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"heatmap\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?fit=640%2C311&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?resize=640%2C311&#038;ssl=1\" alt=\"\" class=\"wp-image-14192\" srcset=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?resize=1024%2C498&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?resize=300%2C146&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?resize=768%2C374&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?resize=1536%2C748&amp;ssl=1 1536w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?w=1664&amp;ssl=1 1664w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?w=1280&amp;ssl=1 1280w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"PARTIE_2_Creer_une_carte_de_Hotspots_concentrations_significatives\"><\/span>PARTIE 2 : Cr\u00e9er une carte de Hotspots (concentrations significatives)<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Objectif_Identifier_les_zones_ou_la_densite_de_points_est_significativement_elevee\"><\/span>Objectif : Identifier les zones o\u00f9 la densit\u00e9 de points est significativement \u00e9lev\u00e9e<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Methode_simple_agregation_calcul\"><\/span>M\u00e9thode simple (agr\u00e9gation + calcul)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Cr\u00e9er une grille r\u00e9guli\u00e8re<\/strong>\n<ul class=\"wp-block-list\">\n<li>Menu : <code>Traitements &gt; Bo\u00eete \u00e0 outils &gt; Cr\u00e9er une grille<\/code><\/li>\n\n\n\n<li>Type de grille : carr\u00e9e ou hexagonale<\/li>\n\n\n\n<li>Taille : 500 m (adapter \u00e0 votre \u00e9chelle)<\/li>\n\n\n\n<li>\u00c9tendue : utiliser l\u2019emprise de votre couche de points<br><\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspot.jpg?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"504\" data-attachment-id=\"14193\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/grillehotspot\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspot.jpg?fit=746%2C588&amp;ssl=1\" data-orig-size=\"746,588\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"grillehotspot\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspot.jpg?fit=640%2C504&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspot.jpg?resize=640%2C504&#038;ssl=1\" alt=\"\" class=\"wp-image-14193\" srcset=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspot.jpg?w=746&amp;ssl=1 746w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspot.jpg?resize=300%2C236&amp;ssl=1 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"419\" data-attachment-id=\"14194\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/grillehotspotcarte\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?fit=1236%2C810&amp;ssl=1\" data-orig-size=\"1236,810\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"grillehotspotcarte\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?fit=640%2C419&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?resize=640%2C419&#038;ssl=1\" alt=\"\" class=\"wp-image-14194\" srcset=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?resize=1024%2C671&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?resize=300%2C197&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?resize=768%2C503&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?resize=241%2C158&amp;ssl=1 241w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?resize=264%2C172&amp;ssl=1 264w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/grillehotspotcarte.jpg?w=1236&amp;ssl=1 1236w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/figure>\n\n\n\n<p><strong>2<\/strong>.<strong>Compter les points par cellule<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Menu : <code>Vecteur &gt; Outils d\u2019analyse &gt; Points dans polygones<\/code><\/li>\n\n\n\n<li>Polygones : la grille<\/li>\n\n\n\n<li>Points : votre couche de points<\/li>\n\n\n\n<li>Champ de sortie : nb_points<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_nbpoints.jpg?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"504\" data-attachment-id=\"14195\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/hotspot_nbpoints\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_nbpoints.jpg?fit=751%2C591&amp;ssl=1\" data-orig-size=\"751,591\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"hotspot_nbpoints\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_nbpoints.jpg?fit=640%2C504&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_nbpoints.jpg?resize=640%2C504&#038;ssl=1\" alt=\"\" class=\"wp-image-14195\" srcset=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_nbpoints.jpg?w=751&amp;ssl=1 751w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_nbpoints.jpg?resize=300%2C236&amp;ssl=1 300w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/figure>\n\n\n\n<p><strong>3.Calculer les valeurs standardis\u00e9es (Z-score simplifi\u00e9)<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Ouvrir la <strong>table attributaire de la grille<\/strong> avec nb_points<\/li>\n\n\n\n<li>Lancer <code>Calculatrice de champ<\/code><\/li>\n\n\n\n<li>Cr\u00e9er un champ zscore avec : <code>(\"nb_points\" - mean(\"nb_points\")) \/ stdev(\"nb_points\")<\/code><\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"313\" data-attachment-id=\"14196\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/hotspot_zscore\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?fit=1036%2C507&amp;ssl=1\" data-orig-size=\"1036,507\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"hotspot_zscore\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?fit=640%2C313&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?resize=640%2C313&#038;ssl=1\" alt=\"\" class=\"wp-image-14196\" srcset=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?resize=1024%2C501&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?resize=300%2C147&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?resize=768%2C376&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_zscore.jpg?w=1036&amp;ssl=1 1036w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/figure>\n\n\n\n<p><strong>4<\/strong>.<strong>Styliser la carte des hotspots<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Clic droit &gt; <code>Propri\u00e9t\u00e9s &gt; Symbologie<\/code><\/li>\n\n\n\n<li>Mode : Gradu\u00e9<\/li>\n\n\n\n<li>Champ : zscore<\/li>\n\n\n\n<li>Palette : rouge \u2192 bleu (zones rouges = hotspots)<\/li>\n\n\n\n<li>Classer par quantiles ou intervalles \u00e9gaux<\/li>\n<\/ul>\n\n\n\n<p><strong>R\u00e9sultat<\/strong> : une grille color\u00e9e indiquant o\u00f9 la densit\u00e9 est sup\u00e9rieure ou inf\u00e9rieure \u00e0 la moyenne.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"640\" height=\"438\" data-attachment-id=\"14197\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/heatmaps-et-cartes-de-hotspots-dans-qgis\/hotspot_final\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?fit=1145%2C783&amp;ssl=1\" data-orig-size=\"1145,783\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"hotspot_final\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?fit=640%2C438&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?resize=640%2C438&#038;ssl=1\" alt=\"\" class=\"wp-image-14197\" srcset=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?resize=1024%2C700&amp;ssl=1 1024w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?resize=300%2C205&amp;ssl=1 300w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?resize=768%2C525&amp;ssl=1 768w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/hotspot_final.jpg?w=1145&amp;ssl=1 1145w\" sizes=\"auto, (max-width: 640px) 100vw, 640px\" \/><\/a><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Heatmaps et cartes de hotspots dans QGIS : comprendre les diff\u00e9rences En analyse spatiale, les heatmaps (ou cartes de chaleur) et les cartes de hotspots sont deux techniques puissantes pour r\u00e9v\u00e9ler des concentrations ou des zones&hellip;<\/p>\n","protected":false},"author":1,"featured_media":14192,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"give_campaign_id":0,"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"sfsi_plus_gutenberg_text_before_share":"","sfsi_plus_gutenberg_show_text_before_share":"","sfsi_plus_gutenberg_icon_type":"","sfsi_plus_gutenberg_icon_alignemt":"","sfsi_plus_gutenburg_max_per_row":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[62],"tags":[3306,171,1613,58],"class_list":["post-14101","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-qgis-2","tag-heatmap","tag-hotspot","tag-hotspot-analysis","tag-qgis"],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/06\/heatmap.jpg?fit=1664%2C810&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p6XU0A-3Fr","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts\/14101","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/comments?post=14101"}],"version-history":[{"count":0,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts\/14101\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/media\/14192"}],"wp:attachment":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/media?parent=14101"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/categories?post=14101"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/tags?post=14101"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}