{"id":9092,"date":"2019-06-17T11:31:35","date_gmt":"2019-06-17T09:31:35","guid":{"rendered":"http:\/\/serveiseducatius.xtec.cat\/cda-delta\/?page_id=9092"},"modified":"2019-06-17T14:34:58","modified_gmt":"2019-06-17T12:34:58","slug":"lentorn-el-riu-ebre","status":"publish","type":"page","link":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/lentorn-el-riu-ebre\/","title":{"rendered":"L’entorn: el riu Ebre"},"content":{"rendered":"
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\"\"<\/a><\/p>\n

L\u2019Ebre entra a Catalunya a partir de l\u2019aiguabarreig amb els seu afluents Segre i Cinca, passat el gran embassament de Mequinensa, i al final d\u2019una gran conca fluvial de 85.399 Km2, que ocupa un 17,3% del territori peninsular, i que recull les aig\u00fces de la Serralada Cant\u00e0brica, els Pirineus i el Sistema Ib\u00e8ric.<\/p>\n

A les Terres de l\u2019Ebre, passat els embassaments de Riba-roja i Flix, el riu s\u2019obre pas entre la Serralada Prelitoral pel Pas de l\u2019Ase i forma un congost que desapareix en entrar a la cubeta de M\u00f3ra. Posteriorment torna a creuar la serralada per un llarg congost \u2014 els estrets de Benifallet o pas de Barrufemes\u2014 fins arribar a l\u2019assut de Xer- ta-Tivenys, d\u2019on surten els canals \u2014 de la dreta i de l\u2019esquerra\u2014 que solquen les planes litorals de Baix Ebre i el Montsi\u00e0 i permeten el conreu de l\u2019arr\u00f2s al Delta.<\/p>\n

En aquest tram final, el riu erosiona els materials calcaris i hi excava una vall al.luvial que es va reomplint dels materials que sedimenta, i forma meandres i illes fluvials fins arribar al tram d\u2019estuari, passada la ciutat de Tortosa, on ha anat formant en arribar a la mar l\u2019extensa plana del delta de l\u2019Ebre de 320 Km2.<\/p>\n

A les vores del riu es donen les condicions ed\u00e0fiques \u00f2ptimes \u2014un s\u00f2l f\u00e8rtil, aigua abundant al s\u00f2l i una certa humitat ambiental\u2014 per al desenvolupament d\u2019una vegetaci\u00f3 exuberant i densa, formada per grans arbres cadu- cifolis com el xop i l\u2019aube, que s\u00f3n estranys en el nostre m\u00f3n mediterrani, acompanyats al sotabosc d\u2019arbustos i lianes com l\u2019heura i el lligabosc, i amb arbres menuts i flexibles \u2014a les parts m\u00e9s inundables\u2014 com el salze blanc i el tamariu.<\/p>\n

Aquest bosc de ribera t\u00e9 una gran import\u00e0ncia ecol\u00f2gica, ja que frena l\u2019erosi\u00f3 de les riuades i fertilitza el terreny, a m\u00e9s de ser l\u2019h\u00e0bitat i lloc de refugi, nidificaci\u00f3 i alimentaci\u00f3 per a un gran nombre d\u2019esp\u00e8cies de mam\u00edfers i aus, que l\u2019utilitzen tamb\u00e9 com a corredor biol\u00f2gic per a despla\u00e7ar-se entre altres espais naturals. Els pagesos han aprofitat aquesta fertilitat per a conrear una extensa horta i fruiterar a les terres properes al riu.<\/p>\n

La construcci\u00f3 dels grans embassaments a la conca de l\u2019Ebre, especialment a mitjan s. XX, ha modificat de manera important el r\u00e8gim hidrol\u00f2gic de l\u2019Ebre al seu tram baix. La retenci\u00f3 de cabals ha comportat una disminuci\u00f3 de l\u2019aigua que arriba al mar, amb efectes sobre l\u2019ecosistema fluvial i sobre la productivitat pesquera i l\u2019aq\u00fcicultura al litoral. La manca de cabals tamb\u00e9 ha fet augmentar temporalment i espacialment la pres\u00e8ncia d\u2019una falca salina que penetra per la desembocadura riu amunt, fins m\u00e9s de 20 Km.<\/p>\n

Una altra conseq\u00fc\u00e8ncia dels embassaments \u00e9s la retenci\u00f3 dels sediments s\u00f2lids que porta el riu. Actualment nom\u00e9s arriben l\u20191% dels que arribaven a principis del s. XX. Aix\u00f2 comporta la regressi\u00f3 i subsid\u00e8ncia (enfonsa- ment) de la plana deltaica, que afegit a la previsi\u00f3 d\u2019augment del nivell del mar a causa del canvi clim\u00e0tic, poden causar la desaparici\u00f3 de gran part del Delta en les pr\u00f2ximes d\u00e8cades.<\/p>\n

 <\/p>\n

\"\"<\/a><\/p>\n<\/div>\n

Veure activitats amb alumnes al riu<\/a><\/strong><\/h5>\n
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 <\/p>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

L\u2019Ebre entra a Catalunya a partir de l\u2019aiguabarreig amb els seu afluents Segre i Cinca, passat el gran embassament de Mequinensa, i al final d\u2019una gran conca fluvial de 85.399 Km2, que ocupa un 17,3% del territori peninsular, i que recull les aig\u00fces de la Serralada Cant\u00e0brica, els Pirineus i el Sistema Ib\u00e8ric. A les […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_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,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-9092","page","type-page","status-publish","hentry"],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/pages\/9092","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/comments?post=9092"}],"version-history":[{"count":4,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/pages\/9092\/revisions"}],"predecessor-version":[{"id":9143,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/pages\/9092\/revisions\/9143"}],"wp:attachment":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-delta\/wp-json\/wp\/v2\/media?parent=9092"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}