﻿{"id":14967,"date":"2025-09-02T10:00:00","date_gmt":"2025-09-02T08:00:00","guid":{"rendered":"https:\/\/www.sigterritoires.fr\/?p=14967"},"modified":"2025-08-24T09:24:31","modified_gmt":"2025-08-24T07:24:31","slug":"logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique","status":"publish","type":"post","link":"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/","title":{"rendered":"Logique floue et SIG (1\/2): une alternative au tout ou rien pour l\u2019analyse g\u00e9ographique"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Modeliser_lincertitude_et_les_transitions_progressives_dans_QGIS_grace_au_plugin_FuzzyAttributes\"><\/span>Mod\u00e9liser l\u2019incertitude et les transitions progressives dans QGIS gr\u00e2ce au plugin FuzzyAttributes.<span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p>Tout n\u2019est pas noir ou blanc en g\u00e9ographie. Pourtant, les outils SIG imposent souvent des choix binaires. Que faire des zones de transition ? Des crit\u00e8res partiellement remplis ? Avec la logique floue, vous pouvez repr\u00e9senter des r\u00e9alit\u00e9s plus subtiles, en attribuant des degr\u00e9s d\u2019appartenance aux objets g\u00e9ographiques. Le plugin <a href=\"https:\/\/www.sigterritoires.fr\/index.php\/fuzzyattributes\/\">FuzzyAttributes<\/a> vous permet d\u2019appliquer ces concepts dans QGIS, facilement. Une avanc\u00e9e pr\u00e9cieuse pour l\u2019analyse environnementale, l\u2019am\u00e9nagement du territoire ou les \u00e9tudes de vuln\u00e9rabilit\u00e9.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\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 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Modeliser_lincertitude_et_les_transitions_progressives_dans_QGIS_grace_au_plugin_FuzzyAttributes\" >Mod\u00e9liser l\u2019incertitude et les transitions progressives dans QGIS gr\u00e2ce au plugin FuzzyAttributes.<\/a><\/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\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Pourquoi_utiliser_des_valeurs_floues_dans_lanalyse_spatiale\" >Pourquoi utiliser des valeurs floues dans l\u2019analyse spatiale ?<\/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\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Le_monde_nest_pas_binaire\" >Le monde n\u2019est pas binaire<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Ce_que_sont_les_valeurs_floues\" >Ce que sont les valeurs floues<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Linteret_dans_lanalyse_multicritere\" >L\u2019int\u00e9r\u00eat dans l\u2019analyse multicrit\u00e8re<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Cas_reel_evaluer_une_zone_a_risques\" >Cas r\u00e9el : \u00e9valuer une zone \u00e0 risques<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#En_resume\" >En r\u00e9sum\u00e9<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Le_plugin_FuzzyAttributes_un_outil_au_service_de_la_nuance\" >Le plugin FuzzyAttributes : un outil au service de la nuance<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Les_fonctions_dappartenance_transformer_les_donnees_en_jugements_flous\" >Les fonctions d\u2019appartenance : transformer les donn\u00e9es en jugements flous<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#1_Lineaire_croissante\" >1. Lin\u00e9aire croissante<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#2_Lineaire_decroissante\" >2. Lin\u00e9aire d\u00e9croissante<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#3_Trapezoidale\" >3. Trap\u00e9zo\u00efdale<\/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\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#4_Triangulaire\" >4. Triangulaire<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#5_Sigmoide_croissante_S\" >5. Sigmo\u00efde croissante (S)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#6_Sigmoide_decroissante_Z\" >6. Sigmo\u00efde d\u00e9croissante (Z)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#7_Gaussienne\" >7. Gaussienne<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#Normalisation_vs_Transformation_floue_quelle_difference\" >Normalisation vs Transformation floue : quelle diff\u00e9rence ?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#1_Normalisation_lineaire_classique\" >1. Normalisation lin\u00e9aire classique<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/#2_Transformation_floue_fonction_dappartenance\" >2. Transformation floue (fonction d\u2019appartenance)<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n\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=\"Pourquoi_utiliser_des_valeurs_floues_dans_lanalyse_spatiale\"><\/span><strong>Pourquoi utiliser des valeurs floues dans l\u2019analyse spatiale ?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Dans nos travaux quotidiens avec les SIG (Syst\u00e8mes d\u2019Information G\u00e9ographique), nous sommes souvent amen\u00e9s \u00e0 travailler avec des donn\u00e9es num\u00e9riques pr\u00e9cises : un taux, une distance, un pourcentage. Mais dans bien des situations, la r\u00e9alit\u00e9 n\u2019est pas aussi nette. Elle est <strong>vague<\/strong>, <strong>incertaine<\/strong>, ou <strong>subjective<\/strong>. Et c\u2019est l\u00e0 qu\u2019interviennent les <strong>valeurs floues<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Le_monde_nest_pas_binaire\"><\/span><strong>Le monde n\u2019est pas binaire<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Prenons un exemple simple : est-ce qu\u2019un sol est \u00ab acide \u00bb ? Si l\u2019on se fie uniquement \u00e0 un seuil de pH, on pourrait dire :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Oui, s\u2019il est inf\u00e9rieur \u00e0 5.5<\/li>\n\n\n\n<li>Non, s\u2019il est sup\u00e9rieur<\/li>\n<\/ul>\n\n\n\n<p>Mais un sol \u00e0 <strong>pH 5.6<\/strong> ? Est-il vraiment si diff\u00e9rent d\u2019un sol \u00e0 <strong>pH 5.4<\/strong> ?<br>Dans la r\u00e9alit\u00e9, la transition est progressive. Il est plus juste de dire que le sol <strong>est plut\u00f4t acide<\/strong>, ou <strong>mod\u00e9r\u00e9ment acide<\/strong>. C\u2019est <strong>cette nuance-l\u00e0<\/strong> que permet la logique floue.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Ce_que_sont_les_valeurs_floues\"><\/span><strong>Ce que sont les valeurs floues<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Une <strong>valeur floue<\/strong> ne dit pas simplement \u00ab\u00a0oui\u00a0\u00bb ou \u00ab\u00a0non\u00a0\u00bb. Elle exprime un <strong>degr\u00e9 d\u2019appartenance<\/strong> \u00e0 une cat\u00e9gorie. Par exemple :<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><td><strong>pH<\/strong><\/td><td><strong>Degr\u00e9 d\u2019appartenance \u00e0 \u00ab sol acide \u00bb<\/strong><\/td><\/tr><\/thead><tbody><tr><td>4.5<\/td><td>1.0 (tr\u00e8s acide)<\/td><\/tr><tr><td>5.0<\/td><td>0.8<\/td><\/tr><tr><td>5.5<\/td><td>0.5<\/td><\/tr><tr><td>6.0<\/td><td>0.2<\/td><\/tr><tr><td>7.0<\/td><td>0.0 (neutre)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>Ce type de repr\u00e9sentation permet de <strong>mieux traduire des ph\u00e9nom\u00e8nes continus<\/strong> dans des processus de d\u00e9cision.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Linteret_dans_lanalyse_multicritere\"><\/span><strong>L\u2019int\u00e9r\u00eat dans l\u2019analyse multicrit\u00e8re<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Lorsque plusieurs crit\u00e8res entrent en jeu \u2014 par exemple, pour d\u00e9terminer l\u2019aptitude d\u2019un site \u00e0 l\u2019agriculture, ou la vuln\u00e9rabilit\u00e9 d\u2019un territoire \u2014, il est souvent difficile de combiner des seuils rigides.<\/p>\n\n\n\n<p>Les fonctions floues permettent de :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Prendre en compte <strong>l\u2019incertitude ou la subjectivit\u00e9<\/strong> des seuils,<\/li>\n\n\n\n<li>Traduire des jugements experts comme \u00ab un sol l\u00e9g\u00e8rement acide est acceptable \u00bb,<\/li>\n\n\n\n<li><strong>Pond\u00e9rer des crit\u00e8res<\/strong> avec des poids in\u00e9gaux ou des r\u00e9ponses asym\u00e9triques.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Cas_reel_evaluer_une_zone_a_risques\"><\/span><strong>Cas r\u00e9el : \u00e9valuer une zone \u00e0 risques<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>Imaginons qu\u2019on veuille \u00e9valuer la <strong>vuln\u00e9rabilit\u00e9 \u00e0 l\u2019\u00e9rosion<\/strong> d\u2019un bassin versant, en combinant :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>La pente,<\/li>\n\n\n\n<li>Le type de sol,<\/li>\n\n\n\n<li>Le couvert v\u00e9g\u00e9tal.<\/li>\n<\/ul>\n\n\n\n<p>Chacun de ces facteurs peut \u00eatre flout\u00e9 :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Une pente douce \u2192 vuln\u00e9rabilit\u00e9 faible (0.2),<\/li>\n\n\n\n<li>Un sol limoneux \u2192 vuln\u00e9rabilit\u00e9 moyenne (0.6),<\/li>\n\n\n\n<li>Un sol nu \u2192 vuln\u00e9rabilit\u00e9 forte (0.9).<\/li>\n<\/ul>\n\n\n\n<p>Une <strong>fonction d\u2019agr\u00e9gation floue<\/strong> permet de combiner ces scores tout en tenant compte de leur importance relative (la pente \u00e9tant plus critique que le sol, par exemple), pour produire une carte de <strong>risque flou<\/strong>, bien plus informative qu\u2019une simple classification \u00ab Risque\/Non risque \u00bb.<\/p>\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=\"En_resume\"><\/span><strong>En r\u00e9sum\u00e9<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><td><strong>Sans logique floue<\/strong><\/td><td><strong>Avec logique floue<\/strong><\/td><\/tr><\/thead><tbody><tr><td>Seuils fixes et arbitraires<\/td><td>Transitions progressives<\/td><\/tr><tr><td>0 ou 1<\/td><td>Degr\u00e9 d\u2019appartenance (ex. 0.7)<\/td><\/tr><tr><td>D\u00e9cisions abruptes<\/td><td>Nuances et pond\u00e9rations fines<\/td><\/tr><tr><td>Risque d\u2019exclure trop<\/td><td>Meilleure inclusivit\u00e9 analytique<\/td><\/tr><\/tbody><\/table><\/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=\"Le_plugin_FuzzyAttributes_un_outil_au_service_de_la_nuance\"><\/span><strong>Le plugin <em>FuzzyAttributes<\/em> : un outil au service de la nuance<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Le plugin <a href=\"https:\/\/github.com\/SigEtTerritoires\/FuzzyAttributes\">FuzzyAttributes<\/a> a \u00e9t\u00e9 con\u00e7u pour <strong>convertir des attributs num\u00e9riques en valeurs floues<\/strong>, et les <strong>combiner via des fonctions d\u2019agr\u00e9gation personnalis\u00e9es<\/strong>.<\/p>\n\n\n\n<p>Il propose :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Des fonctions floues classiques (lin\u00e9aire, triangulaire, gaussienne, sigmo\u00efde\u2026),<\/li>\n\n\n\n<li>Un outil visuel pour configurer les fonctions,<\/li>\n\n\n\n<li>La possibilit\u00e9 d\u2019agr\u00e9ger plusieurs crit\u00e8res selon des logiques asym\u00e9triques,<\/li>\n\n\n\n<li>Un export dans un champ <a href=\"https:\/\/www.sigterritoires.fr\/index.php\/le-format-geopackage-et-qgis-3\/\">GeoPackage<\/a> pr\u00eat \u00e0 l\u2019usage.<\/li>\n<\/ul>\n\n\n\n<p>Gr\u00e2ce \u00e0 cet outil, vous pouvez passer d\u2019une vision rigide du monde \u00e0 une <strong>analyse plus souple, plus fid\u00e8le \u00e0 la complexit\u00e9 du r\u00e9el.<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\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=\"Les_fonctions_dappartenance_transformer_les_donnees_en_jugements_flous\"><\/span><strong>Les fonctions d\u2019appartenance : transformer les donn\u00e9es en jugements flous<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<p>Voici les principales fonctions disponibles dans le plugin <strong>FuzzyAttributes<\/strong>, avec des exemples concrets :<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"1_Lineaire_croissante\"><\/span><strong>1. Lin\u00e9aire croissante<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/linearcroiss.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"280\" height=\"187\" data-attachment-id=\"14986\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/linearcroiss\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/linearcroiss.png?fit=280%2C187&amp;ssl=1\" data-orig-size=\"280,187\" 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=\"linearcroiss\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/linearcroiss.png?fit=280%2C187&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/linearcroiss.png?resize=280%2C187&#038;ssl=1\" alt=\"\" class=\"wp-image-14986\"\/><\/a><\/figure>\n<\/div>\n\n\n<ul class=\"wp-block-list\">\n<li> Utilis\u00e9e quand \u00ab\u202fplus c\u2019est grand, mieux c\u2019est\u202f\u00bb.<\/li>\n\n\n\n<li>Exemple : l\u2019altitude pour une esp\u00e8ce de montagne, o\u00f9 l\u2019aptitude augmente progressivement \u00e0 partir de 800 m jusqu\u2019\u00e0 1800 m.<\/li>\n\n\n\n<li>Param\u00e8tres : a (valeur minimale) et b (valeur maximale).\n<ul class=\"wp-block-list\">\n<li>Formule :\n<ul class=\"wp-block-list\">\n<li>0 si x \u2264 a<\/li>\n\n\n\n<li>(x \u2212 a) \/ (b \u2212 a) si a &lt; x &lt; b<\/li>\n\n\n\n<li>1 si x \u2265 b<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/lineardecroiss.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"280\" height=\"187\" data-attachment-id=\"14987\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/lineardecroiss\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/lineardecroiss.png?fit=280%2C187&amp;ssl=1\" data-orig-size=\"280,187\" 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=\"lineardecroiss\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/lineardecroiss.png?fit=280%2C187&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/lineardecroiss.png?resize=280%2C187&#038;ssl=1\" alt=\"\" class=\"wp-image-14987\"\/><\/a><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2_Lineaire_decroissante\"><\/span><strong>2. Lin\u00e9aire d\u00e9croissante<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Cas inverse : \u00ab\u202fmoins c\u2019est grand, mieux c\u2019est\u202f\u00bb.<\/li>\n\n\n\n<li>Exemple : taux de pollution, o\u00f9 une valeur \u00e9lev\u00e9e est mauvaise.<\/li>\n\n\n\n<li>Param\u00e8tres : a, b comme pr\u00e9c\u00e9demment, mais invers\u00e9s.<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/trapezoidale.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"280\" height=\"187\" data-attachment-id=\"14988\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/trapezoidale\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/trapezoidale.png?fit=280%2C187&amp;ssl=1\" data-orig-size=\"280,187\" 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=\"trapezoidale\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/trapezoidale.png?fit=280%2C187&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/trapezoidale.png?resize=280%2C187&#038;ssl=1\" alt=\"\" class=\"wp-image-14988\"\/><\/a><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"3_Trapezoidale\"><\/span><strong>3. Trap\u00e9zo\u00efdale<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Repr\u00e9sente une zone de \u00ab\u202fpleine appartenance\u202f\u00bb entour\u00e9e de transitions.<\/li>\n\n\n\n<li>Exemple : une temp\u00e9rature id\u00e9ale entre 18 \u00b0C et 22 \u00b0C, acceptable entre 16 \u00b0C et 24 \u00b0C.<\/li>\n\n\n\n<li>Param\u00e8tres : a (d\u00e9but transition), b (d\u00e9but zone id\u00e9ale), c (fin zone id\u00e9ale), d (fin transition).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/triangulaire.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"280\" height=\"187\" data-attachment-id=\"14989\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/triangulaire\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/triangulaire.png?fit=280%2C187&amp;ssl=1\" data-orig-size=\"280,187\" 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=\"triangulaire\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/triangulaire.png?fit=280%2C187&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/triangulaire.png?resize=280%2C187&#038;ssl=1\" alt=\"\" class=\"wp-image-14989\"\/><\/a><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"4_Triangulaire\"><\/span><strong>4. Triangulaire<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Variante simplifi\u00e9e de la trap\u00e9zo\u00efdale.<\/li>\n\n\n\n<li>Exemple : noter une humidit\u00e9 \u00ab\u202fid\u00e9ale\u202f\u00bb \u00e0 un point pr\u00e9cis (ex. 65 %), mais tol\u00e9rer un flou autour.<\/li>\n\n\n\n<li>Param\u00e8tres : a (d\u00e9but mont\u00e9e), b (sommet), c (fin descente).<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmocroiss.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"280\" height=\"187\" data-attachment-id=\"14990\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/sigmocroiss\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmocroiss.png?fit=280%2C187&amp;ssl=1\" data-orig-size=\"280,187\" 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=\"sigmocroiss\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmocroiss.png?fit=280%2C187&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmocroiss.png?resize=280%2C187&#038;ssl=1\" alt=\"\" class=\"wp-image-14990\"\/><\/a><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"5_Sigmoide_croissante_S\"><\/span><strong>5. Sigmo\u00efde croissante (S)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Repr\u00e9sente une croissance lente, puis rapide, puis stabilis\u00e9e.<\/li>\n\n\n\n<li>Exemple : acceptabilit\u00e9 d\u2019un d\u00e9bit de rivi\u00e8re pour l\u2019irrigation.<\/li>\n\n\n\n<li>Param\u00e8tres : c (valeur centrale), \u03b1 (pente).<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignright size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmodecroiss.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"280\" height=\"187\" data-attachment-id=\"14991\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/sigmodecroiss\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmodecroiss.png?fit=280%2C187&amp;ssl=1\" data-orig-size=\"280,187\" 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=\"sigmodecroiss\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmodecroiss.png?fit=280%2C187&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/sigmodecroiss.png?resize=280%2C187&#038;ssl=1\" alt=\"\" class=\"wp-image-14991\"\/><\/a><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"6_Sigmoide_decroissante_Z\"><\/span><strong>6. Sigmo\u00efde d\u00e9croissante (Z)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Courbe en \u00ab\u202fZ invers\u00e9\u202f\u00bb : d\u00e9croissance lente \u2192 rapide \u2192 plateau.<\/li>\n\n\n\n<li>Exemple : tol\u00e9rance \u00e0 la salinit\u00e9 du sol pour une culture.<\/li>\n<\/ul>\n\n\n\n<p>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/gaussienne.png?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"282\" height=\"202\" data-attachment-id=\"14992\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/gaussienne\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/gaussienne.png?fit=282%2C202&amp;ssl=1\" data-orig-size=\"282,202\" 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=\"gaussienne\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/gaussienne.png?fit=282%2C202&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/gaussienne.png?resize=282%2C202&#038;ssl=1\" alt=\"\" class=\"wp-image-14992\"\/><\/a><\/figure>\n<\/div>\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"7_Gaussienne\"><\/span><strong>7. Gaussienne<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Fonction en cloche.<\/li>\n\n\n\n<li>Exemple : sensibilit\u00e9 optimale d\u2019une plante \u00e0 un pH pr\u00e9cis.<\/li>\n\n\n\n<li>Param\u00e8tres : c (centre), \u03c3 (\u00e9cart-type contr\u00f4lant la largeur).<\/li>\n<\/ul>\n\n\n\n<p>.<\/p>\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=\"Normalisation_vs_Transformation_floue_quelle_difference\"><\/span><strong>Normalisation vs Transformation floue : quelle diff\u00e9rence ?<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"1_Normalisation_lineaire_classique\"><\/span><strong> 1. Normalisation lin\u00e9aire classique<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>La <strong>normalisation min-max<\/strong> consiste \u00e0 convertir une valeur num\u00e9rique brute<strong><em> x<\/em><\/strong> vers une \u00e9chelle normalis\u00e9e allant de 0 \u00e0 1.<br>Elle s\u2019effectue en soustrayant la valeur minimale de l\u2019ensemble, puis en divisant par l\u2019intervalle max\u2061(x)\u2212min\u2061(x)  selon la formule : <\/p>\n\n\n\n<p class=\"has-text-align-center\">x<sub>norm<\/sub>=x\u2212min\u2061(x) \/ max\u2061(x)\u2212min\u2061(x)<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Avantage<\/strong> : rapide, universelle, intuitive.<\/li>\n\n\n\n<li><strong>Inconv\u00e9nient<\/strong> : <strong>ne tient pas compte de la signification des valeurs<\/strong>. Tout est trait\u00e9 comme proportionnel.<\/li>\n<\/ul>\n\n\n\n<p><strong>Exemple<\/strong> :<br>Pour une temp\u00e9rature entre 10 \u00b0C et 30 \u00b0C, 20 \u00b0C devient 0.5\u2026 mais cela ne signifie pas n\u00e9cessairement que 20 \u00b0C est \u00ab\u202fmod\u00e9r\u00e9ment favorable\u202f\u00bb. C\u2019est juste au milieu de l\u2019intervalle.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"2_Transformation_floue_fonction_dappartenance\"><\/span><strong>2. Transformation floue (fonction d\u2019appartenance)<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h3>\n\n\n\n<p>La transformation floue ne se contente pas de \u00ab remettre \u00e0 l\u2019\u00e9chelle \u00bb : elle exprime <strong>un degr\u00e9 de satisfaction<\/strong>, <strong>de pr\u00e9f\u00e9rence<\/strong> ou <strong>d\u2019appartenance<\/strong> \u00e0 une cat\u00e9gorie.<\/p>\n\n\n\n<p>Par exemple, une temp\u00e9rature de 20 \u00b0C peut \u00eatre :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>parfaite (appartenance = 1) pour une esp\u00e8ce,<\/li>\n\n\n\n<li>acceptable (appartenance = 0.6),<\/li>\n\n\n\n<li>insuffisante (appartenance = 0.2),<br>en fonction d\u2019une <strong>fonction d\u00e9finie par l\u2019expert ou le mod\u00e8le<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p>Cela permet :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>de <strong>mod\u00e9liser des pr\u00e9f\u00e9rences humaines ou biologiques<\/strong>,<\/li>\n\n\n\n<li>de <strong>rendre le syst\u00e8me plus robuste aux variations extr\u00eames<\/strong>,<\/li>\n\n\n\n<li>d\u2019<strong>introduire des zones d\u2019incertitude<\/strong> ou de transition (ex. \u00ab\u202fni bon ni mauvais\u202f\u00bb).<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><strong>Comparaison visuelle <\/strong><\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><td><strong>Valeur brute<\/strong><\/td><td><strong>Normalis\u00e9e (lin\u00e9aire)<\/strong><\/td><td><strong>Floue (triangulaire centr\u00e9e sur 20\u202f\u00b0C)<\/strong><\/td><\/tr><\/thead><tbody><tr><td>10 \u00b0C<\/td><td>0.0<\/td><td>0.0<\/td><\/tr><tr><td>15 \u00b0C<\/td><td>0.25<\/td><td>0.5<\/td><\/tr><tr><td>20 \u00b0C<\/td><td>0.5<\/td><td>1.0 (optimum)<\/td><\/tr><tr><td>25 \u00b0C<\/td><td>0.75<\/td><td>0.5<\/td><\/tr><tr><td>30 \u00b0C<\/td><td>1.0<\/td><td>0.0<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><strong>Conclusion<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>La normalisation<\/strong> est utile pour rendre des donn\u00e9es comparables.<\/li>\n\n\n\n<li><strong>La transformation floue<\/strong> est essentielle quand on veut <strong>mod\u00e9liser des pr\u00e9f\u00e9rences, des incertitudes ou des jugements qualitatifs<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p>En somme :<br><strong>Normalisation = mise \u00e0 l\u2019\u00e9chelle<\/strong><br><strong>Flou = interpr\u00e9tation du sens<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><a href=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/normalisation_fuzzy.jpg?ssl=1\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"604\" height=\"299\" data-attachment-id=\"14968\" data-permalink=\"https:\/\/www.sigterritoires.fr\/index.php\/logique-floue-et-sig-1-2-une-alternative-au-tout-ou-rien-pour-lanalyse-geographique\/normalisation_fuzzy\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/normalisation_fuzzy.jpg?fit=604%2C299&amp;ssl=1\" data-orig-size=\"604,299\" 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=\"normalisation_fuzzy\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/normalisation_fuzzy.jpg?fit=604%2C299&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/normalisation_fuzzy.jpg?resize=604%2C299&#038;ssl=1\" alt=\"\" class=\"wp-image-14968\" srcset=\"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/normalisation_fuzzy.jpg?w=604&amp;ssl=1 604w, https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/normalisation_fuzzy.jpg?resize=300%2C149&amp;ssl=1 300w\" sizes=\"auto, (max-width: 604px) 100vw, 604px\" \/><\/a><\/figure>\n<\/div>\n\n\n<p>Voici un graphique comparant deux m\u00e9thodes de transformation d\u2019un attribut num\u00e9rique\u202f:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>La normalisation lin\u00e9aire (min-max)<\/strong> : transforme lin\u00e9airement une variable entre 0 et 1. Chaque valeur est proportionnellement convertie en fonction de ses bornes.<\/li>\n\n\n\n<li><strong>La transformation floue (fonction triangulaire)<\/strong> : accorde une importance maximale \u00e0 une valeur centrale (ici 20\u00b0C) et d\u00e9cro\u00eet vers 0 de mani\u00e8re sym\u00e9trique.<\/li>\n<\/ul>\n\n\n\n<p><strong>Diff\u00e9rence essentielle<\/strong> :<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>La normalisation ne donne aucune pr\u00e9f\u00e9rence : 30 est consid\u00e9r\u00e9 aussi important (1) que 20.<\/li>\n\n\n\n<li>La transformation floue int\u00e8gre une <strong>zone de pertinence maximale<\/strong> (le sommet de la fonction) et traduit l&rsquo;id\u00e9e de <strong>valeurs plus ou moins compatibles<\/strong> avec un crit\u00e8re id\u00e9al.<\/li>\n<\/ul>\n\n\n\n<p>Ce principe est fondamental pour mod\u00e9liser des pr\u00e9f\u00e9rences humaines, des seuils flous ou des zones d\u2019incertitude.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p><strong>\u00c0 suivre\u2026<\/strong><br>Dans une deuxi\u00e8me partie, nous verrons comment combiner plusieurs cartes ou indicateurs flous \u00e0 l\u2019aide de fonctions d\u2019agr\u00e9gation. Cette \u00e9tape permettra de passer d\u2019analyses isol\u00e9es \u00e0 une synth\u00e8se globale, en tenant compte de l\u2019incertitude et des pr\u00e9f\u00e9rences propres \u00e0 chaque projet.<\/p>\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>Mod\u00e9liser l\u2019incertitude et les transitions progressives dans QGIS gr\u00e2ce au plugin FuzzyAttributes. Tout n\u2019est pas noir ou blanc en g\u00e9ographie. Pourtant, les outils SIG imposent souvent des choix binaires. Que faire des zones de transition ?&hellip;<\/p>\n","protected":false},"author":1,"featured_media":15184,"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":[243,1945,62],"tags":[3544,3624,240,279,58],"class_list":["post-14967","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fzy","category-pluigin","category-qgis-2","tag-attributs","tag-fuzzyattributes","tag-logique-floue","tag-plugin","tag-qgis"],"aioseo_notices":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/www.sigterritoires.fr\/wp-content\/uploads\/2025\/08\/fzy_attr_image.jpg?fit=1084%2C582&ssl=1","jetpack_shortlink":"https:\/\/wp.me\/p6XU0A-3Tp","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts\/14967","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=14967"}],"version-history":[{"count":0,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/posts\/14967\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/media\/15184"}],"wp:attachment":[{"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/media?parent=14967"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/categories?post=14967"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sigterritoires.fr\/index.php\/wp-json\/wp\/v2\/tags?post=14967"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}