{"id":935,"date":"2004-12-03T09:37:00","date_gmt":"2004-12-03T08:37:00","guid":{"rendered":"https:\/\/kids.esa.int\/lakes\/"},"modified":"2026-10-08T00:33:57","modified_gmt":"2026-10-07T22:33:57","slug":"lakes","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fi\/lakes\/","title":{"rendered":"J\u00e4rvet"},"content":{"rendered":"
\n

J\u00e4rvet ovat arvokkaita vesi- ja ravintol\u00e4hteit\u00e4, erityisesti k\u00f6yhiss\u00e4 maissa. Ne ovat kuitenkin alttiita vahingoittumiselle liikak\u00e4yt\u00f6n, saastumisen ja ilmastonmuutoksen vuoksi. J\u00e4rvien koon ja rantaviivojen muutokset ovat helposti havaittavissa avaruudesta.<\/p>\n<\/div>\n

T\u00e4llaiset tiedot ovat eritt\u00e4in arvokkaita syrj\u00e4isill\u00e4 alueilla ja k\u00f6yhiss\u00e4 maissa. Ne osoittavat, miten maatalous ja s\u00e4\u00e4 vaikuttavat vedenkorkeuksiin. Ne my\u00f6s varoittavat tulvista l\u00e4hist\u00f6ll\u00e4 asuvia ihmisi\u00e4.<\/p>\n

Satelliitit tarjoavat my\u00f6s t\u00e4rke\u00e4\u00e4 tietoa j\u00e4rvien tilasta, kuten veden l\u00e4mp\u00f6tilasta, v\u00e4rist\u00e4 ja pilaantumisesta.<\/p>\n

Yksi dramaattisimmista esimerkeist\u00e4 on Aralj\u00e4rvi Kazakstanissa. Se oli aikoinaan maailman nelj\u00e4nneksi suurin j\u00e4rvi, mutta on kutistunut viimeisten 45 vuoden aikana alle puoleen alkuper\u00e4isest\u00e4 koostaan.
ESA:n Envisat-satelliitin kaltaisten satelliittien ottamat kuvat osoittavat, kuinka ihmisen toiminta on v\u00e4hent\u00e4nyt Aralj\u00e4rveen virtaavien jokien virtaaman vain pieneksi virraksi. T\u00e4m\u00e4n seurauksena j\u00e4rvi on k\u00e4yt\u00e4nn\u00f6ss\u00e4 jakautunut kahtia. Sen reunoille on nyt muodostunut 40 000 neli\u00f6kilometrin laajuinen valkoisen, suolaisen maaper\u00e4n peitt\u00e4m\u00e4 aavikko.<\/p>\n

Avaruudessa sijaitsevat tutkalaitteet voivat mitata my\u00f6s j\u00e4rvien ja niihin virtaavien jokien muuttuvia vedenkorkeuksia. Suurimmassa osassa Aralj\u00e4rve\u00e4 vedenpinta on laskenut 14 metri\u00e4 1960-luvulta l\u00e4htien. J\u00e4rven pohjoisosassa toteutetut toimet vedenpinnan nostamiseksi ja suolapitoisuuden v\u00e4hent\u00e4miseksi ovat kuitenkin tuottaneet jonkin verran tuloksia viime vuosina.<\/p>","protected":false},"excerpt":{"rendered":"

Lakes are valuable sources of water and food, particularly in poor countries. However, they are easily damaged by overuse, pollution and climate change. Changes in the sizes and shorelines of […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2003\/07\/the_shrinking_aral_sea_seen_from_envisat_s_meris2\/17873002-2-eng-GB\/The_shrinking_Aral_Sea_seen_from_Envisat_s_MERIS.jpg","esa_banner_description":"The shrinking Aral Sea, seen from Envisat's MERIS","esa_banner_credit":"ESA","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2003\/07\/The_shrinking_Aral_Sea_seen_from_Envisat_s_MERIS2","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[42,10,66],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-935","post","type-post","status-publish","format-standard","hentry","category-earth","category-learn","category-water-world","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/935","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/comments?post=935"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/935\/revisions"}],"predecessor-version":[{"id":2078,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/posts\/935\/revisions\/2078"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/media?parent=935"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/categories?post=935"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/tags?post=935"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/panel?post=935"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/language?post=935"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/age?post=935"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/duration?post=935"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/resource_type?post=935"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/audience?post=935"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fi\/wp-json\/wp\/v2\/wf_post_folders?post=935"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}