{"id":6640,"date":"2019-08-09T09:09:49","date_gmt":"2019-08-09T08:09:49","guid":{"rendered":"https:\/\/www.vtei.cz\/?p=6640"},"modified":"2024-07-16T15:59:20","modified_gmt":"2024-07-16T14:59:20","slug":"water-loss-by-evaporation-from-free-water-surface","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2019\/08\/water-loss-by-evaporation-from-free-water-surface\/","title":{"rendered":"Water loss by evaporation from free water surface"},"content":{"rendered":"

<\/i> This article is available in Czech only. For translation or more information on this topic, please contact author.<\/h4>\n

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Souhrn<\/h2>\n

Vliv v\u00fdparu z\u00a0vodn\u00ed hladiny na celkovou hydrologickou bilanci povod\u00ed m\u016f\u017ee b\u00fdt zna\u010dn\u00fd, a\u00a0to p\u0159edev\u0161\u00edm v\u00a0letech s\u00a0n\u00edzk\u00fdmi sr\u00e1\u017ekov\u00fdmi \u00fahrny. Na povod\u00edch s\u00a0v\u00fdznamn\u00fdm zastoupen\u00edm vodn\u00edch ploch se vlivem oteplov\u00e1n\u00ed jeho v\u00fdznam zvy\u0161uje. V\u00a0p\u0159\u00edsp\u011bvku je vy\u010d\u00edslena ztr\u00e1ta vody v\u00fdparem z\u00a0rybni\u010dn\u00ed soustavy ji\u017en\u00edch \u010cech s\u00a0dopady na celkov\u00fd odtok z\u00a0povod\u00ed Lu\u017enice. Je tak\u00e9 zm\u00edn\u011bn vliv v\u00fdparu z\u00a0jezer vznikl\u00fdch hydrick\u00fdmi rekultivacemi \u00fazem\u00ed zasa\u017een\u00fdch povrchovou t\u011b\u017ebou v\u00a0severn\u00edch \u010cech\u00e1ch.<\/p>\n\"\"<\/a>\n

\u00davod<\/h2>\n

Pr\u016fb\u011bh po\u010das\u00ed v\u00a0posledn\u00edch letech, zejm\u00e9na v\u00a0letech 2014 a\u017e 2018, kdy se vyskytuj\u00ed vysok\u00e9 teploty vzduchu a\u00a0n\u00edzk\u00e9 celkov\u00e9 sr\u00e1\u017ekov\u00e9 \u00fahrny, je vhodn\u00fdm d\u016fvodem pro vyhodnocen\u00ed vlivu zvy\u0161uj\u00edc\u00edho se v\u00fdparu z\u00a0vodn\u00ed hladiny na celkov\u00fd odtok z\u00a0povod\u00ed.<\/p>\n

V\u00a0pop\u0159ed\u00ed z\u00e1jmu je klimatick\u00e1 zm\u011bna, jej\u00ed\u017e dopady maj\u00ed dalekos\u00e1hl\u00fd vliv na r\u016fzn\u00e9 oblasti lidsk\u00fdch \u010dinnost\u00ed. Vodn\u00ed hospod\u00e1\u0159stv\u00ed, je\u017e je v\u00a0\u010cR v\u00fdlu\u010dn\u011b z\u00e1visl\u00e9 na sr\u00e1\u017ekov\u00fdch vod\u00e1ch, je z\u00a0tohoto hlediska dopady klimatick\u00e9 zm\u011bny v\u00fdznamn\u011b ohro\u017eeno a\u00a0m\u016f\u017ee b\u00fdt citeln\u011b zasa\u017eeno. Aktu\u00e1ln\u011b se jako nejv\u011bt\u0161\u00ed probl\u00e9m jev\u00ed zvy\u0161uj\u00edc\u00ed se teplota vzduchu, je\u017e m\u00e1 za n\u00e1sledek zvy\u0161ov\u00e1n\u00ed \u00fazemn\u00edho v\u00fdparu a\u00a0v\u00fdparu z\u00a0vodn\u00edch ploch. Tyto ztr\u00e1ty vody z\u00a0hydrologick\u00e9ho syst\u00e9mu nejsou dostate\u010dn\u011b nahrazeny sr\u00e1\u017ekov\u00fdmi \u00fahrny, je\u017e jsou na \u00fazem\u00ed \u010cR nerovnom\u011brn\u011b rozlo\u017eeny, a\u00a0t\u00edm p\u00e1dem se v\u00a0\u010cR vyskytuj\u00ed oblasti, kde celkov\u00fd v\u00fdpar p\u0159evy\u0161uje sr\u00e1\u017eky a\u00a0doch\u00e1z\u00ed k\u00a0projev\u016fm sucha (nap\u0159. [1, 2]). Na extr\u00e9mn\u00ed projevy klimatick\u00e9 zm\u011bny je zapot\u0159eb\u00ed reagovat za pomoci navrhov\u00e1n\u00ed adapta\u010dn\u00edch opat\u0159en\u00ed, je\u017e dok\u00e1\u017e\u00ed negativn\u00ed dopady klimatick\u00e9 zm\u011bny zm\u00edrnit, nebo jim zabr\u00e1nit.<\/p>\n

V\u00a0\u010dl\u00e1nku je pops\u00e1n vliv v\u00fdparu z\u00a0vodn\u00ed plochy na povod\u00ed Lu\u017enice po uz\u00e1v\u011brov\u00fd profil Bechyn\u011b. Na tomto \u00fazem\u00ed se nach\u00e1z\u00ed nejv\u00fdznamn\u011bj\u0161\u00ed rybni\u010dn\u00ed soustavy v\u00a0\u010cR. Vyhodnocen\u00ed such\u00fdch let s\u00a0extr\u00e9mn\u011b n\u00edzk\u00fdmi \u00fahrny sr\u00e1\u017eek 2015 a\u00a02018 \u010cesk\u00fdm hydrometeorologick\u00fdm \u00fastavem (\u010cHM\u00da) [3] d\u00e1v\u00e1 d\u016fle\u017eit\u00fd podklad pro zamy\u0161len\u00ed se nad navrhov\u00e1n\u00edm mal\u00fdch vodn\u00edch n\u00e1dr\u017e\u00ed a\u00a0jejich lokalizaci. Ty mohou p\u0159i vyu\u017eit\u00ed pro rybochovn\u00e9 pot\u0159eby a\u00a0\u0161patn\u00fdm um\u00edst\u011bn\u00edm zhor\u0161ovat celkovou hydrologickou situaci na povod\u00ed. V\u00a0z\u00e1v\u011bru jsou v\u00a0p\u0159\u00edsp\u011bvku uvedeny hlavn\u00ed v\u00fdsledky studie V\u00daV TGM, je\u017e se mj. zab\u00fdvala ur\u010den\u00edm v\u00fdparu z\u00a0vodn\u00ed hladiny jezera Most. Problematika v\u00fdparu z\u00a0vodn\u00ed hladiny je v\u00a0souvislosti se zat\u00e1p\u011bn\u00edm jam po povrchov\u00e9 t\u011b\u017eb\u011b vzhledem k\u00a0charakteru po\u010das\u00ed v\u00a0posledn\u00edch letech vysoce aktu\u00e1ln\u00ed. Zejm\u00e9na se \u0159e\u0161\u00ed vhodnost hydrick\u00fdch rekultivac\u00ed u\u00a0nepr\u016fto\u010dn\u00fdch jezer, tam kde je v\u00fdpar vy\u0161\u0161\u00ed ne\u017e sr\u00e1\u017ekov\u00e9 \u00fahrny.<\/p>\n

Data a\u00a0metody<\/h2>\n

Z\u00e1jmov\u00e9 oblasti<\/h3>\n

Pro pops\u00e1n\u00ed vlivu rybni\u010dn\u00ed soustavy na celkov\u00fd odtok z\u00a0povod\u00ed bylo vybr\u00e1no povod\u00ed Lu\u017enice po profil Bechyn\u011b (obr.\u00a01<\/em>), kter\u00e9 je typick\u00e9 vysok\u00fdm zastoupen\u00edm vodn\u00edch ploch na sv\u00e9m \u00fazem\u00ed. Nach\u00e1z\u00ed se zde rybni\u010dn\u00ed soustavy ji\u017en\u00edch \u010cech, je\u017e svou plochou zauj\u00edmaj\u00ed 82,64 km2<\/sup>, z\u00a0celkov\u00e9 plochy povod\u00ed 4 055 km2<\/sup>. Pod\u00edl vodn\u00edch ploch na celkov\u00e9m \u00fazem\u00ed je p\u0159ibli\u017en\u011b 2 %. Rybn\u00edky jsou v\u011bt\u0161inou vyu\u017e\u00edvan\u00e9 k\u00a0um\u011bl\u00e9mu chovu ryb. Ne v\u0161echny rybn\u00edky jsou propojeny s\u00a0\u0159\u00ed\u010dn\u00ed soustavou, nicm\u00e9n\u011b prezentovan\u00e9 v\u00fdsledky v\u00fdpo\u010dtu v\u00fdparu maj\u00ed sp\u00ed\u0161e informativn\u00ed charakter a\u00a0jsou uvedeny pro \u0159\u00e1dovou p\u0159edstavu vlivu v\u00fdparu z\u00a0vodn\u00edch ploch na celkov\u00fd odtok z\u00a0povod\u00ed b\u011bhem such\u00fdch obdob\u00ed. Dlouhodob\u00fd pr\u016fm\u011br teploty vzduchu na povod\u00ed Lu\u017enice je 7,5\u20138 \u00b0C, dlouhodob\u00e9 ro\u010dn\u00ed sr\u00e1\u017ekov\u00e9 \u00fahrny 600\u2013650 mm [5].<\/p>\n\"\"<\/a>\n

Obr.\u00a01. Z\u00e1jmov\u00e1 oblast povod\u00ed Lu\u017enice po profil Bechyn\u011b, v\u00fdparom\u011brn\u00e1 a\u00a0meteorologick\u00e9 stanice (naho\u0159e: sr\u00e1\u017ekov\u00e9 \u00fahrny, dole: pr\u016fm\u011brn\u00e1 teplota vzduchu)
\nFig. 1. Lu\u017enice catchment (Bechyn\u011b), evaporation and meteorological stations\u2028(above: map of precipitation, down: map of average air temperature)<\/h6>\n

Druhou z\u00e1jmovou lokalitou je jezero Most, vznikl\u00e9 zatopen\u00edm b\u00fdval\u00e9ho povrchov\u00e9ho Dolu Le\u017e\u00e1ky slou\u017e\u00edc\u00edho do roku 1999 k\u00a0t\u011b\u017eb\u011b hn\u011bd\u00e9ho uhl\u00ed. Jezero m\u00e1 plochu 311 ha a\u00a0objem vody p\u0159ibli\u017en\u011b 70 mil. m3<\/sup>. Kompletn\u011b napu\u0161t\u011bno bylo v\u00a0roce 2014. Dlouhodob\u00fd pr\u016fm\u011br teploty vzduchu na \u00fazem\u00ed jezera Most je 8,5\u20139\u00a0\u00b0C, dlouhodob\u00e9 ro\u010dn\u00ed sr\u00e1\u017ekov\u00e9 \u00fahrny 500\u2013550 mm [5].<\/p>\n

Hlavn\u00edm zdrojem dat pro odvozov\u00e1n\u00ed empirick\u00fdch vztah\u016f pro v\u00fdpo\u010det v\u00fdparu z\u00a0vodn\u00ed hladiny je v\u00fdparom\u011brn\u00e1 stanice Hlasivo u\u00a0T\u00e1bora.<\/p>\n

V\u00fdparom\u011brn\u00e1 stanice Hlasivo<\/h3>\n

Pozorov\u00e1n\u00ed v\u00fdparu z\u00a0vodn\u00ed hladiny prob\u00edh\u00e1 ve v\u00fdparom\u011brn\u00e9 stanici Hlasivo u\u00a0T\u00e1bora od roku 1957, poskytuje tedy dostate\u010dn\u011b dlouhou \u0159adu m\u011b\u0159en\u00e9ho v\u00fdparu z\u00a0vodn\u00ed hladiny (obr.\u00a02<\/em>) spole\u010dn\u011b s\u00a0dal\u0161\u00edmi meteorologick\u00fdmi veli\u010dinami (teplota vzduchu, relativn\u00ed vlhkost vzduchu, teplota p\u016fdy v\u00a0r\u016fzn\u00fdch hloubk\u00e1ch, rychlost a\u00a0sm\u011br v\u011btru, \u00fahrn a\u00a0intenzita sr\u00e1\u017eek, glob\u00e1ln\u00ed slune\u010dn\u00ed radiace, teplota vody ve v\u00fdparom\u011brech). Pozorov\u00e1n\u00ed ostatn\u00edch meteorologick\u00fdch veli\u010din spole\u010dn\u011b s\u00a0v\u00fdparem dovoluje odvozov\u00e1n\u00ed empirick\u00fdch vztah\u016f, je\u017e slou\u017e\u00ed pro v\u00fdpo\u010det v\u00fdparu z\u00a0vodn\u00ed hladiny i\u00a0v\u00a0jin\u00fdch oblastech \u010cR. Na obr.\u00a02<\/em> lze pozorovat n\u00e1r\u016fst pr\u016fm\u011brn\u00e9ho denn\u00edho v\u00fdparu z\u00a0vodn\u00ed hladiny cca o\u00a00,5 mm\/den v\u00a0posledn\u00edch letech, to p\u0159edstavuje zv\u00fd\u0161en\u00ed v\u00fdparu z\u00a0vodn\u00ed hladiny ve vegeta\u010dn\u00edm obdob\u00ed t\u00e9m\u011b\u0159 o\u00a0100 mm (pro p\u0159edstavu na plochu jezera Most se jedn\u00e1 nav\u00fd\u0161en\u00ed o\u00a0cca\u00a0300 tis. m3<\/sup>\/rok).<\/p>\n\"\"<\/a>\n

Obr.\u00a02. Pr\u016fm\u011brn\u00fd denn\u00ed v\u00fdpar v\u00a0sezon\u011b kv\u011bten a\u017e \u0159\u00edjen v\u00a0letech 1957\u20132018
\nFig. 2. Mean daily evaporation in season May\u2013October in 1957\u20132018<\/h6>\n

Dlouhodob\u00fd pr\u016fm\u011br teploty vzduchu je 7,5\u20138 \u00b0C, dlouhodob\u00e9 ro\u010dn\u00ed sr\u00e1\u017ekov\u00e9 \u00fahrny 550\u2013600 mm [5].<\/p>\n

V\u00fdpar se m\u011b\u0159\u00ed obvykle v\u00a0obdob\u00ed od dubna (kv\u011btna) do \u0159\u00edjna, kdy se teplota pohybuje v\u011bt\u0161inou nad bodem mrazu a\u00a0nedoch\u00e1z\u00ed k\u00a0zamrz\u00e1n\u00ed v\u00fdparom\u011brn\u00e9ho za\u0159\u00edzen\u00ed. Ve stanici Hlasivo se po mnohalet\u00fdch zku\u0161enostech omezila m\u011b\u0159\u00edc\u00ed perioda na m\u011bs\u00edce kv\u011bten a\u017e \u0159\u00edjen.<\/p>\n

Pro v\u00fdpo\u010det v\u00fdparu na vodn\u00edch ploch\u00e1ch na povod\u00ed Lu\u017enice byl pou\u017eit nejjednodu\u0161\u0161\u00ed empirick\u00fd vztah, jen\u017e vy\u017eaduje pouze m\u011b\u0159en\u00e9 hodnoty teploty vzduchu. Tento vzorec (uveden n\u00ed\u017ee) byl odvozen na z\u00e1klad\u011b z\u00e1vislosti pozorovan\u00e9ho v\u00fdparu a\u00a0teploty vzduchu ve stanici Hlasivo za obdob\u00ed 1957\u20132018. Vzorce s\u00a0vyu\u017eit\u00edm glob\u00e1ln\u00ed slune\u010dn\u00ed radiace, teploty vody, p\u0159\u00edpadn\u011b jejich kombinace, d\u00e1vaj\u00ed p\u0159esn\u011bj\u0161\u00ed v\u00fdsledky, nicm\u00e9n\u011b tyto m\u011b\u0159en\u00e9 veli\u010diny jsme nem\u011bli k\u00a0dispozici a\u00a0\u00fa\u010delem bylo poskytnout p\u0159ibli\u017en\u00fd odhad, pro kter\u00fd n\u00e1m vztah vyhovuje. Odvozen\u00ed empirick\u00fdch vztah\u016f pro v\u00fdpo\u010det v\u00fdparu z\u00a0vodn\u00ed hladiny je uvedeno v\u00a0pr\u016fb\u011b\u017en\u00e9 zpr\u00e1v\u011b projektu TJ01000196 Vytvo\u0159en\u00ed software pro v\u00fdpo\u010det v\u00fdparu z\u00a0vodn\u00ed hladiny pro podm\u00ednky \u010cR [4]. Odvozen\u00fd vzorec je:<\/p>\n\"\"<\/a>\n\n\n\n\n
kde<\/td>\nVVH<\/em><\/td>\nje<\/td>\nv\u00fdpar z\u00a0vodn\u00ed hladiny [mm\/m\u011bs\u00edc],<\/td>\n<\/tr>\n
<\/td>\nTvzd<\/em><\/td>\n<\/td>\npr\u016fm\u011brn\u00e1 m\u011bs\u00ed\u010dn\u00ed teplota vzduchu [\u00b0C].<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Pou\u017eit\u00e1 data<\/h3>\n

Pr\u016fb\u011bh pozorovan\u00e9ho odtoku a\u00a0celkov\u00fdch sr\u00e1\u017eek ve vodom\u011brn\u00e9 stanici Bechyn\u011b na Lu\u017enici byl p\u0159evzat ze zpr\u00e1vy \u010cHM\u00da Sucho v\u00a0roce 2018 [3]. Ve zpr\u00e1v\u011b je uveden hydrogram pr\u016fm\u011brn\u00fdch denn\u00edch pr\u016ftok\u016f za\u00a0obdob\u00ed duben a\u017e \u0159\u00edjen 2018 a\u00a0porovn\u00e1n s\u00a0rokem 2015. Tyto dva roky byly extr\u00e9mn\u00ed z\u00a0hlediska n\u00edzk\u00fdch \u00fahrn\u016f sr\u00e1\u017eek, jejich distribuc\u00ed v\u00a0pr\u016fb\u011bhu roku a\u00a0nav\u00edc rok 2018 byl nejteplej\u0161\u00edm rokem na \u00fazem\u00ed \u010cR zaznamenan\u00fdm v\u00a0obdob\u00ed od roku 1961.<\/p>\n

Obr\u00e1zek 3<\/em> ukazuje bilanci sr\u00e1\u017eek a\u00a0potenci\u00e1ln\u00ed evapotranspirace, kdy v\u00a0roce 2018 (duben a\u017e z\u00e1\u0159\u00ed) byly t\u00e9m\u011b\u0159 na cel\u00e9m \u00fazem\u00ed \u010cR sr\u00e1\u017eky podstatn\u011b ni\u017e\u0161\u00ed.<\/p>\n\"\"<\/a>\n

Obr.\u00a03. Rozd\u00edl sumy sr\u00e1\u017eek a\u00a0potenci\u00e1ln\u00ed evapotranspirace travn\u00edho porostu v\u00a0mm za duben a\u017e z\u00e1\u0159\u00ed 2018 [3]
\nFig. 3. Difference rainfall-potential evapotranspiration in mm (April\u2013September 2018) [3]<\/h6>\n

Celkov\u00e9 rozlo\u017een\u00ed dlouhodob\u00fdch \u00fahrn\u016f sr\u00e1\u017eek na plo\u0161e povod\u00ed a\u00a0v\u00a0okol\u00ed bylo z\u00edsk\u00e1no z\u00a0map v\u00a0Atlasu podneb\u00ed \u010ceska od kolektivu autor\u016f z\u00a0\u010cHM\u00da [5]. Obr\u00e1zky 7, 8<\/em> a\u00a09<\/em> byly sestrojeny na z\u00e1klad\u011b dat ze t\u0159\u00ed klimatick\u00fdch stanic (Bechyn\u011b, T\u0159ebo\u0148-Lu\u017enice a\u00a0\u0160ev\u011bt\u00edn-Mazelov).<\/p>\n

Pro v\u00fdpo\u010dty v\u00fdparu na jeze\u0159e Most byly k\u00a0dispozici m\u011b\u0159en\u00e9 hodnoty v\u00fdparu z\u00a0plovouc\u00edho v\u00fdparom\u011bru na jeze\u0159e spolu s\u00a0dal\u0161\u00edmi m\u011b\u0159en\u00fdmi klimatick\u00fdmi veli\u010dinami od Palivov\u00e9ho kombin\u00e1tu \u00dast\u00ed, s. p., d\u00e1le byla k\u00a0dispozici klimatick\u00e1 data (sr\u00e1\u017ekov\u00e9 \u00fahrny, teplota vzduchu, rychlost v\u011btru) z\u00a0nedalek\u00e9 stanice \u010cHM\u00da Kopisty.<\/p>\n

Zn\u00e1zorn\u011bn\u00e9 dva mapov\u00e9 listy (obr.\u00a04<\/em> a\u00a05<\/em>) zachycuj\u00edc\u00ed klimatologickou vodn\u00ed bilanci (rozd\u00edl mezi ro\u010dn\u00edm \u00fahrnem sr\u00e1\u017eek a\u00a0referen\u010dn\u00ed evapotranspirac\u00ed) pro kalend\u00e1\u0159n\u00ed rok pro sou\u010dasn\u00e9 (1981\u20132015) klimatick\u00e9 podm\u00ednky a\u00a0podm\u00ednky o\u010dek\u00e1van\u00e9 v\u00a0obdob\u00ed 2021\u20132040 na z\u00e1klad\u011b odhadu p\u011bti glob\u00e1ln\u00edch cirkula\u010dn\u00edch model\u016f. Ty reprezentuj\u00ed jak pomysln\u00fd st\u0159ed rozsahu zm\u011bn teplot a\u00a0\u00fahrn\u016f sr\u00e1\u017eek (IPSL), tak modely p\u0159edpokl\u00e1daj\u00edc\u00ed sp\u00ed\u0161e m\u00edrn\u00fd n\u00e1r\u016fst sr\u00e1\u017eek (CNMR a\u00a0MRI), resp. pokles sr\u00e1\u017eek (HadGEM, BNU) ve vegeta\u010dn\u00edm obdob\u00ed a\u00a0li\u0161\u00ed se i\u00a0m\u00edrou n\u00e1r\u016fstu teplot. Modely HadGEM a\u00a0CNMR zastupuj\u00ed modely s\u00a0v\u011bt\u0161\u00edm n\u00e1r\u016fstem teploty a\u00a0modely MRI a\u00a0BNU sp\u00ed\u0161e s\u00a0men\u0161\u00edm n\u00e1r\u016fstem teplot. Na prvn\u00edm obr\u00e1zku je zachycena vl\u00e1hov\u00e1 bilance pro b\u011b\u017en\u00fd rok (medi\u00e1n) a\u00a0na druh\u00e9m pro tzv. 10let\u00e9 sucho (10% percentil). Z\u00a0map je z\u0159ejm\u00e9, kde se nach\u00e1zej\u00ed oblasti, kter\u00e9 jsou bilan\u010dn\u011b deficitn\u00ed. Odhad v\u00fdvoje klimatu nazna\u010duje prohlubuj\u00edc\u00ed se vodn\u00ed deficit pro v\u0161ech p\u011bt glob\u00e1ln\u00edch cirkula\u010dn\u00edch model\u016f a\u00a0zv\u00fd\u0161en\u00ed deficitu vl\u00e1hov\u00e9 bilance na v\u011bt\u0161in\u011b \u00fazem\u00ed jak v\u00a0b\u011b\u017en\u00e9m roce, tak v\u00a0p\u0159\u00edpad\u011b 10let\u00e9ho sucha. V\u00fdsledky vych\u00e1z\u00ed z\u00a0Generelu vodn\u00edho hospod\u00e1\u0159stv\u00ed krajiny \u010cR [6].<\/p>\n\"\"<\/a>\n

Obr.\u00a04. Vl\u00e1hov\u00e1 bilance za obdob\u00ed leden\u2013prosinec pro b\u011b\u017en\u00fd rok pro sou\u010dasn\u00e9 klimatick\u00e9 podm\u00ednky (1981\u20132015) a\u00a0o\u010dek\u00e1van\u00e9 v\u00a0obdob\u00ed 2021\u20132040 pro 5 GCM model\u016f [6]
\nFig. 4. Average moister balance for period from January to December for current climatic conditions (1981\u20132015) and for predictions of 5 GCM models for the period 2021\u20132040 [6]<\/h6>\n\"\"<\/a>\n
Obr.\u00a05. Vl\u00e1hov\u00e1 bilance za obdob\u00ed leden\u2013prosinec pro 10let\u00e9 sucho pro sou\u010dasn\u00e9 klimatick\u00e9 podm\u00ednky (1981\u20132015) a\u00a0o\u010dek\u00e1van\u00e9 v\u00a0obdob\u00ed 2021\u20132040 pro 5 GCM model\u016f [6]
\nFig. 5. Moisture balance in a\u00a010 year drought for the period from January to December for current climate conditions (1981\u20132015) and for predictions of 5 GCM models for the period 2021\u20132040 [6]<\/h6>\n

V\u00fdsledky<\/h2>\n

Povod\u00ed Lu\u017enice<\/h3>\n

Vliv rybni\u010dn\u00ed soustavy na zv\u00fd\u0161en\u00ed sr\u00e1\u017eek<\/h4>\n

Prvn\u00ed \u0159e\u0161enou \u00falohou bylo posoudit, jestli rybni\u010dn\u00ed soustava zv\u011bt\u0161uje sr\u00e1\u017eky a\u00a0do jak\u00e9 m\u00edry. Jde o\u00a0efekt takzvan\u00e9ho mal\u00e9ho ob\u011bhu vody.<\/p>\n

Na map\u011b pr\u016fm\u011brn\u00e9ho ro\u010dn\u00edho sr\u00e1\u017ekov\u00e9ho \u00fahrnu sr\u00e1\u017eek (obr.\u00a01<\/em>) nen\u00ed patrn\u00e9, \u017ee by se p\u0159\u00edtomnost vodn\u00edch ploch v\u00a0povod\u00ed Lu\u017enice projevila zv\u011bt\u0161en\u00edm sr\u00e1\u017eek v\u00a0jejich okol\u00ed. \u00da\u010dinek vodn\u00edch ploch na lok\u00e1ln\u00ed zv\u00fd\u0161en\u00ed sr\u00e1\u017eek je viditeln\u00fd z\u00a0obr.\u00a06<\/em>, kde je zn\u00e1zorn\u011bn pr\u016fm\u011brn\u00fd ro\u010dn\u00ed po\u010det sr\u00e1\u017ekov\u00fdch dn\u00ed s\u00a0\u00fahrnem vy\u0161\u0161\u00edm ne\u017e\u00a00,1\u00a0mm. Nicm\u00e9n\u011b tato skute\u010dnost ji\u017e nen\u00ed viditeln\u00e1 na map\u011b pr\u016fm\u011brn\u00e9ho ro\u010dn\u00edho po\u010dtu sr\u00e1\u017ekov\u00fdch dn\u00ed s\u00a0\u00fahrnem vy\u0161\u0161\u00edm ne\u017e 1 mm (obr.\u00a010<\/em>).<\/p>\n\"\"<\/a>\n

Obr.\u00a06. Pr\u016fm\u011brn\u00fd ro\u010dn\u00ed po\u010det sr\u00e1\u017ekov\u00fdch dn\u00ed s\u00a0\u00fahrnem vy\u0161\u0161\u00edm ne\u017e 0,1 mm [5]
\nFig. 6. Mean annual number of days with rain higher than 0.1 mm [5]<\/h6>\n

Na z\u00e1klad\u011b v\u00fd\u0161e uveden\u00fdch skute\u010dnost\u00ed lze konstatovat, \u017ee \u00fa\u010dinkem vodn\u00edch ploch v\u00a0povod\u00ed Lu\u017enice je zv\u011bt\u0161en\u00ed po\u010dtu sr\u00e1\u017eek jen do velikosti 0,1 mm. Zna\u010dn\u00e1 \u010d\u00e1st sr\u00e1\u017eek velikosti do 0,1 mm je patrn\u011b tvo\u0159ena usazen\u00fdmi sr\u00e1\u017ekami, kter\u00e9 v\u00a0such\u00fdch obdob\u00edch prosp\u00edvaj\u00ed vegetaci. Rozd\u00edl po\u010dtu dn\u00ed se sr\u00e1\u017ekami do 0,1 mm v\u00a0okol\u00ed rybni\u010dn\u00ed soustavy od okoln\u00edho \u00fazem\u00ed je p\u0159ibli\u017en\u011b 50 dn\u00ed. Ro\u010dn\u00ed zv\u00fd\u0161en\u00ed sr\u00e1\u017eek je tedy cca 5 mm. Z\u00a0hlediska celkov\u00e9ho ro\u010dn\u00edho \u00fahrnu je to m\u00e9n\u011b ne\u017e 1 %, co\u017e je v\u00a0hydrologick\u00e9 bilanci \u00fazem\u00ed zanedbateln\u00e9. Podle [7] se z\u00a0v\u00fdparu nad pevninou do tvorby sr\u00e1\u017eek zapoj\u00ed v\u00a0p\u00e1su dlouh\u00e9m 500 km 8,8 %. P\u0159i odhadnut\u00e9 \u0161\u00ed\u0159i p\u00e1su, ve kter\u00e9m se sr\u00e1\u017eka z\u00a0rybni\u010dn\u00ed soustavy v\u00a0povod\u00ed Lu\u017enice uplat\u0148uje hodnotou 20 km, by voda vypa\u0159en\u00e1 z\u00a0rybn\u00edk\u016f zv\u011bt\u0161ila sr\u00e1\u017eky v\u00a0\u00fazem\u00ed 20 \u00d7 500\u00a0km o\u00a00,06\u00a0mm\/m\u011bs\u00edc. Tento fakt potvrzuje i\u00a0graf na obr.\u00a07<\/em>, kter\u00fd porovn\u00e1v\u00e1 \u010detnosti sr\u00e1\u017ekov\u00fdch \u00fahrn\u016f s\u00a0dan\u00fdm \u00fahrnem (jedn\u00e1 se o\u00a0vyhlazen\u00fd histogram), pro dv\u011b meteorologick\u00e9 stanice nach\u00e1zej\u00edc\u00ed se v\u00a0rybni\u010dn\u00ed soustav\u011b a\u00a0jednu mimo ni (viz\u00a0obr.\u00a01<\/em>, tabulka 1<\/em>). Na grafu je mo\u017en\u00e9 pozorovat rozd\u00edl \u010detnost\u00ed ni\u017e\u0161\u00edch denn\u00edch sr\u00e1\u017ekov\u00fdch \u00fahrn\u016f, kdy stanice \u0160ev\u011bt\u00edn a\u00a0T\u0159ebo\u0148 vykazuj\u00ed vy\u0161\u0161\u00ed po\u010det dn\u016f se sr\u00e1\u017ekov\u00fdm \u00fahrnem. V\u00a0tabulce 1<\/em> jsou uvedeny po\u010dty dn\u00ed v\u00a0roce se sr\u00e1\u017ekov\u00fdm \u00fahrnem pro jednotliv\u00e1 obdob\u00ed. Pr\u016fm\u011brn\u00fd po\u010det dn\u00ed se sr\u00e1\u017ekou v\u011bt\u0161\u00ed ne\u017e 0,1 mm za obdob\u00ed 1961\u20132016 je u\u00a0stanic nach\u00e1zej\u00edc\u00edch se v\u00a0rybni\u010dn\u00ed soustav\u011b 165, o\u00a020 v\u00edce ne\u017e ve stanici Bechyn\u011b. Obr\u00e1zek 8<\/em> reprezentuje \u010dasov\u00fd v\u00fdvoj v\u00a0po\u010dtu dn\u00ed se sr\u00e1\u017ekov\u00fdm \u00fahrnem. Je z\u0159ejm\u00e9 a\u00a0zaj\u00edmav\u00e9, \u017ee tento po\u010det dn\u00ed v\u00a0posledn\u00edch letech roste, a\u00a0to pr\u00e1v\u011b u\u00a0sr\u00e1\u017eky s\u00a0n\u00edzk\u00fdm \u00fahrnem (obr.\u00a09<\/em>).<\/p>\n\"\"<\/a>\n

Obr.\u00a07. V\u00fdskyt sr\u00e1\u017ekov\u00fdch \u00fahrn\u016f od 0,1 mm (v\u010detn\u011b) do 5 mm pro jednotliv\u00e9 stanice
\nFig. 7. Occurrence of precipitation amounts from 0.1 mm (inclusive) to 5 mm for selected stations<\/h6>\n\"\"<\/a>\n
Obr.\u00a08. Po\u010det dn\u00ed se sr\u00e1\u017ekov\u00fdm \u00fahrnem v\u011bt\u0161\u00edm ne\u017e 0,1 mm v\u010detn\u011b v\u00a0jednotliv\u00fdch letech (k\u0159ivka je vyhlazena metodou loess); barevn\u00fd p\u00e1s zna\u010d\u00ed interval spolehlivosti na 0,95
\nFig. 8. Number of days with total precipitation higher than 0.1 mm inclusive (the curve is smoothed by loess method); color belt represents confidence interval level 0.95<\/h6>\n\"\"<\/a>\n
Obr.\u00a09. Po\u010det dn\u00ed se sr\u00e1\u017ekov\u00fdm \u00fahrnem v\u011bt\u0161\u00edm ne\u017e 0,1 mm a\u00a0men\u0161\u00edm ne\u017e 0,2 mm v\u010detn\u011b v\u00a0jednotliv\u00fdch letech (k\u0159ivka je vyhlazena metodou loess); barevn\u00fd p\u00e1s zna\u010d\u00ed interval spolehlivosti na 0,95
\nFig. 9. Number of days with total precipitation higher than 0.1 mm and less than 0.2 mm inclusive (the curve is smoothed by loess method); color belt represents confidence interval level 0.95<\/h6>\n\"\"<\/a>\n

 <\/p>\n

Obr.\u00a010. Pr\u016fm\u011brn\u00fd ro\u010dn\u00ed po\u010det sr\u00e1\u017ekov\u00fdch dn\u00ed s\u00a0\u00fahrnem vy\u0161\u0161\u00edm ne\u017e 1 mm [5]
\nFig. 10. Mean annual number of days with rain higher than 1 mm [5]<\/h6>\n

Vliv v\u00fdparu na celkov\u00fd odtok z\u00a0povod\u00ed v\u00a0obdob\u00ed sucha<\/h4>\n

Na obr.\u00a011<\/em> jsou uvedeny hydrogramy pr\u016fm\u011brn\u00fdch denn\u00edch pr\u016ftok\u016f na Lu\u017enici v\u00a0profilu Bechyn\u011b pro roky 2015 a\u00a02018. Z\u00a0pr\u016fb\u011bhu je mo\u017en\u00e9 vypozorovat, \u017ee pr\u016fb\u011bh denn\u00edch pr\u016ftok\u016f byl v\u00a0obdob\u00ed od dubna do listopadu velice podobn\u00fd,\u00a0v\u00a0obdob\u00ed od p\u016flky \u010dervence a\u017e do konce z\u00e1\u0159\u00ed pr\u016fm\u011brn\u00e9 denn\u00ed pr\u016ftoky nedosahovaly ani hodnoty Q364 <\/sub>v\u00a0obou zmi\u0148ovan\u00fdch roc\u00edch.<\/p>\n

Tabulka 1. Po\u010det dn\u00ed se sr\u00e1\u017ekov\u00fdm \u00fahrnem v\u011bt\u0161\u00edm ne\u017e 0,1 mm v\u010detn\u011b
\nTable 1. Number of days with a\u00a0total precipitation higher than 0.1 mm (inclusive)<\/h5>\n\"\"<\/a>\n

Pro vy\u010d\u00edslen\u00ed vlivu v\u00fdparu z\u00a0vodn\u00edch ploch na povod\u00ed Lu\u017enice byl na z\u00e1klad\u011b pr\u016fm\u011brn\u00fdch m\u011bs\u00ed\u010dn\u00edch teplot vzduchu z\u00a0v\u00fdparom\u011brn\u00e9 stanice Hlasivo spo\u010d\u00edt\u00e1n pr\u016fm\u011brn\u00fd v\u00fdpar, od kter\u00e9ho byly d\u00e1le ode\u010dteny pr\u016fm\u011brn\u00e9 sr\u00e1\u017eky. Tato pr\u016fm\u011brn\u00e1 ztr\u00e1ta vody v\u00fdparem byla na z\u00e1klad\u011b celkov\u00e9 plochy vodn\u00edch ploch na povod\u00ed (82,64 km2<\/sup>) p\u0159evedena na pr\u016ftok v\u00a0jednotk\u00e1ch m3<\/sup>\/s\u00a0(obr.\u00a012<\/em>). Z\u00a0grafu je patrn\u00e9, \u017ee vliv v\u00fdparu z\u00a0vodn\u00edch ploch na povod\u00ed Lu\u017enice zna\u010dnou \u010d\u00e1st vegeta\u010dn\u00ed sezony od kv\u011btna do z\u00e1\u0159\u00ed p\u0159evy\u0161uje v\u00a0profilu Bechyn\u011b m-denn\u00ed pr\u016ftok Q364<\/sub> (1,78 m3<\/sup>\/s), v\u00a0maximech dosahuje dokonce hodnot Q355<\/sub> (2,91 m3<\/sup>\/s).<\/p>\n\"\"<\/a>\n

Obr.\u00a011. Hydrogram pr\u016fm\u011brn\u00fdch denn\u00edch pr\u016ftok\u016f na Lu\u017enici v\u00a0profilu Bechyn\u011b [3]
\nFig. 11. Daily mean runoff (Lu\u017enice, Bechyn\u011b) [3]<\/h6>\n\"\"<\/a>\n
Obr.\u00a012. V\u00fdpar z\u00a0celkov\u00e9 plochy rybn\u00edk\u016f v\u00a0povod\u00ed Lu\u017enice nad Bechyn\u00ed redukovan\u00fd o\u00a0sr\u00e1\u017eky a\u00a0p\u0159eveden\u00fd do m\u011b\u0159\u00edtka pr\u016ftok\u016f v\u00a0porovn\u00e1n\u00ed s\u00a0Q355<\/sub> a\u00a0Q364
\n<\/sub>Fig. 12. The evaporation of the total area of the ponds in the Lu\u017enice catchment, reduced by precipitation and converted into a\u00a0flow rate compared to Q355<\/sub> and Q364<\/sub><\/h6>\n

Vliv v\u00fdparu z\u00a0vodn\u00ed hladiny na ztr\u00e1tu vody z\u00a0jezera Most<\/h4>\n

Podle mapy z\u00a0Atlasu podneb\u00ed \u010ceska [5] je v\u00a0lokalit\u011b jezera Most dlouhodob\u00fd pr\u016fm\u011brn\u00fd ro\u010dn\u00ed \u00fahrn sr\u00e1\u017eek mezi 450 a\u017e 550 mm a\u00a0dlouhodob\u00fd pr\u016fm\u011brn\u00fd ro\u010dn\u00ed v\u00fdpar z\u00a0vodn\u00ed hladiny v\u00a0p\u00e1smu 600 a\u017e 650 mm. Pokud od sebe ode\u010dteme pr\u016fm\u011brn\u00e9 hodnoty z\u00a0t\u011bchto rozmez\u00ed, dostaneme 625 – 500 = 125 mm, co\u017e zp\u016fsobuje dlouhodob\u00fd pr\u016fm\u011brn\u00fd ro\u010dn\u00ed pokles hladiny o\u00a012,5 cm. Podle mapy dlouhodob\u00e9 ro\u010dn\u00ed vl\u00e1hov\u00e9 bilance (p\u016fdn\u00ed) je pr\u016fm\u011brn\u00fd ro\u010dn\u00ed deficit 200 mm. V\u00a0p\u0159\u00edpad\u011b such\u00fdch a\u00a0tepl\u00fdch let, co\u017e je p\u0159\u00edpad posledn\u00edch rok\u016f, jsou sr\u00e1\u017eky podstatn\u011b ni\u017e\u0161\u00ed a\u00a0v\u00fdpar z\u00a0vodn\u00ed hladiny vy\u0161\u0161\u00ed, vodn\u00ed bilance je tedy v\u00edce deficitn\u00ed. Na z\u00e1klad\u011b pozorovan\u00fdch sr\u00e1\u017ekov\u00fdch \u00fahrn\u016f od roku 1961 a\u00a0v\u00fdparu z\u00a0vodn\u00ed hladiny vypo\u010dten\u00e9ho na z\u00e1klad\u011b pozorovan\u00e9 teploty vzduchu se ro\u010dn\u00ed deficit sr\u00e1\u017eky\u00a0\u2013 v\u00fdpar pohybuje v\u00a0posledn\u00edch letech okolo hodnoty -300 mm\/rok, jak je patrn\u00e9 z\u00a0obr.\u00a013.<\/em><\/p>\n\"\"<\/a>\n

Obr.\u00a013. Rozd\u00edl sr\u00e1\u017eky\u00a0\u2013 v\u00fdpar pro obdob\u00ed 1961\u20132017 na jeze\u0159e Most (te\u010dkovan\u011b 5let\u00fd klouzav\u00fd pr\u016fm\u011br)
\nFig. 13. Difference rainfall\u00a0\u2013 evaporation in the period 1961\u20132017 in the area Lake Most (dotted 5-year moving average)<\/h6>\n

Z\u00a0porovn\u00e1n\u00ed pozorovan\u00fdch hodnot v\u00fdparu plovouc\u00edm v\u00fdparom\u011brem na jeze\u0159e Most a\u00a0dat z\u00a0v\u00fdparom\u011brn\u00e9 stanice Hlasivo (obr.\u00a014<\/em>) pro obdob\u00ed 13. 7. 2017 (za\u010d\u00e1tek m\u00edstn\u00edho pozorov\u00e1n\u00ed) a\u017e 31. 10. 2017 je vid\u011bt vysok\u00e1 m\u00edra shody v\u00a0letn\u00edch m\u011bs\u00edc\u00edch a\u00a0vy\u0161\u0161\u00ed v\u00fdpar z\u00a0vodn\u00ed hladiny jezera Most v\u00a0m\u011bs\u00edc\u00edch z\u00e1\u0159\u00ed a\u00a0\u0159\u00edjen. Tento rozd\u00edl je zp\u016fsoben\u00fd rozd\u00edlem teploty vody, kdy si jezero dr\u017e\u00ed vy\u0161\u0161\u00ed teplotu ne\u017e mal\u00fd v\u00fdparom\u011br, kter\u00fd na zm\u011bny teploty vzduchu reaguje t\u00e9m\u011b\u0159 okam\u017eit\u011b [8]. Nav\u00edc v\u00fdpar z\u00a0jezera je v\u00edce ovlivn\u011bn rychlost\u00ed v\u011btru.<\/p>\n

V\u00a0letech 2016 a\u00a02017 byl na lokalit\u011b jezera Most vypo\u010d\u00edt\u00e1n v\u00fdpar z\u00a0vodn\u00ed hladiny v\u00a0rozmez\u00ed 700\u2013900 mm za rok. V\u00a0obdob\u00ed let 1961 a\u017e 2017 doch\u00e1zelo ke zvy\u0161ov\u00e1n\u00ed pr\u016fm\u011brn\u00e9 teploty vzduchu s\u00a0pr\u016fm\u011brn\u00fdm gradientem 0,378 \u00b0C za 10 let, co\u017e m\u011blo za n\u00e1sledek zvy\u0161ov\u00e1n\u00ed pr\u016fm\u011brn\u00e9ho v\u00fdparu z\u00a0vodn\u00ed hladiny a\u00a0zvy\u0161ov\u00e1n\u00ed deficitu sr\u00e1\u017eky\u00a0\u2013 v\u00fdpar. N\u00e1r\u016fst teploty vzduchu pro oblast jezera Most do roku 2055 se o\u010dek\u00e1v\u00e1 v\u00a0rozmez\u00ed 0,27\u20130,37 za 10 let, ro\u010dn\u00ed sr\u00e1\u017ekov\u00e9 \u00fahrny z\u016fstanou sp\u00ed\u0161e stejn\u00e9, lze proto o\u010dek\u00e1vat dal\u0161\u00ed zvy\u0161ov\u00e1n\u00ed vl\u00e1hov\u00e9ho deficitu ve prosp\u011bch ztr\u00e1t vody. Tyto v\u00fdsledky jsou p\u0159evzaty z\u00a0v\u00fdzkumn\u00e9 zpr\u00e1vy Beran a\u00a0kol.\u00a0[8]. Pro p\u0159edstavu lze uv\u00e9st, \u017ee zv\u00fd\u0161en\u00ed pr\u016fm\u011brn\u00e9ho denn\u00edho v\u00fdparu o\u00a01 mm se rovn\u00e1 zv\u00fd\u0161en\u00ed \u00fabytku vody na plo\u0161e jezera o\u00a0p\u0159ibli\u017en\u011b 3\u00a0000 m3<\/sup> vody za jeden den.<\/p>\n\"\"<\/a>\n

Obr.\u00a014. Porovn\u00e1n\u00ed pozorovan\u00e9ho v\u00fdparu z\u00a0plovouc\u00edho v\u00fdparom\u011bru na jeze\u0159e Most a\u00a0ze stanice Hlasivo
\nFig. 14. Comparison of observed evaporation from floating evaporator on Lake Most and from Hlasivo station<\/h6>\n

Z\u00e1v\u011br<\/h2>\n

Pokud mal\u00e9 vodn\u00ed n\u00e1dr\u017ee nebudou ur\u010deny pro nadlep\u0161ov\u00e1n\u00ed pr\u016ftok\u016f v\u00a0obdob\u00edch hydrologick\u00e9ho sucha, co\u017e neumo\u017e\u0148uje jejich vyu\u017eit\u00ed k\u00a0intenzivn\u00edmu chovu ryb, bude jejich efekt na odtok z\u00a0povod\u00ed z\u00e1visl\u00fd na tom, zda v\u00a0obdob\u00ed sucha sr\u00e1\u017eky, kter\u00e9 na hladinu spadnou, jsou v\u011bt\u0161\u00ed ne\u017e v\u00fdpar z\u00a0hladiny. V\u00a0opa\u010dn\u00e9m p\u0159\u00edpad\u011b, tj. obvykle, rybn\u00edky v\u00a0obdob\u00ed sucha odtok z\u00a0povod\u00ed vlivem intenzivn\u00edho v\u00fdparu zmen\u0161uj\u00ed. V\u00fdznamn\u00fd vliv na zv\u00fd\u0161en\u00ed sr\u00e1\u017eek v\u00a0bezprost\u0159edn\u00edm okol\u00ed nebyl prok\u00e1z\u00e1n. Vliv v\u00fdparu z\u00a0vodn\u00edch ploch na povod\u00ed Lu\u017enice na celkov\u00fd odtok z\u00a0povod\u00ed je vlivem vysok\u00e9ho zastoupen\u00ed vodn\u00edch ploch zna\u010dn\u00fd. V\u00a0letn\u00edch m\u011bs\u00edc\u00edch dosahuje ztr\u00e1ta vody v\u00fdparem hodnoty 3 m3<\/sup>\/s, co\u017e se v\u00a0profilu Bechyn\u011b rovn\u00e1 pr\u016ftoku Q355<\/sub>. Pozitivn\u00ed vliv na mikroklima a\u00a0estetick\u00e9 funkce krajiny nebyly v\u00a0r\u00e1mci p\u0159\u00edsp\u011bvku \u0159e\u0161eny.<\/p>\n

Pro zaj\u00edmavost, byly vyhodnoceny m\u011b\u0159en\u00e9 hodnoty v\u00fdparu z\u00a0v\u00fdparom\u011brn\u00e9 stanice v\u00a0Praze-Podbab\u011b za obdob\u00ed 28. 3.\u201328. 4. 2019, kdy byla pr\u016fm\u011brn\u00e1 teplota vzduchu 11 \u00b0C a\u00a0spadlo pouh\u00fdch 9 mm sr\u00e1\u017eek. Za toto obdob\u00ed se vypa\u0159ilo 56\u00a0mm, co\u017e v\u00a0p\u0159\u00edpad\u011b podobn\u00e9ho pr\u016fb\u011bhu po\u010das\u00ed v\u00a0dal\u0161\u00edch m\u011bs\u00edc\u00edch m\u016f\u017ee m\u00edt za n\u00e1sledek dal\u0161\u00ed rekordn\u00ed rok z\u00a0pohledu ztr\u00e1t vody v\u00fdparem.<\/p>\n

I\u00a0p\u0159es nejistoty spojen\u00e9 s\u00a0modelov\u00e1n\u00edm klimatu v\u00a0budouc\u00edch \u010dasov\u00fdch horizontech lze, na z\u00e1klad\u011b dosavadn\u00edho v\u00fdvoje klimatu \u010cR v\u00a0posledn\u00edch letech, jednozna\u010dn\u011b potvrdit zvy\u0161ov\u00e1n\u00ed pr\u016fm\u011brn\u00e9 ro\u010dn\u00ed teploty vzduchu, co\u017e m\u00e1 vzhledem ke stagnuj\u00edc\u00ed velikosti sr\u00e1\u017ekov\u00fdch \u00fahrn\u016f v\u00fdznamn\u00fd vliv na v\u00fdslednou bilanci v\u00fdpar-sr\u00e1\u017ekov\u00fd \u00fahrn. P\u0159i pl\u00e1nov\u00e1n\u00ed hydrick\u00fdch rekultivac\u00ed na \u00fazem\u00edch po povrchov\u00e9 t\u011b\u017eb\u011b je t\u0159eba s\u00a0t\u011bmito fakty po\u010d\u00edtat, jeliko\u017e ztr\u00e1ty vody v\u00fdparem jsou na velk\u00fdch vodn\u00edch ploch\u00e1ch zna\u010dn\u00e9.<\/p>\n

Pod\u011bkov\u00e1n\u00ed<\/h3>\n

P\u0159\u00edsp\u011bvek byl prezentov\u00e1n na konferenci Rybn\u00edky 2019 (13. 6. 2019\u201314. 6. 2019, Praha). Problematika jezera Most byla \u0159e\u0161ena v\u00a0r\u00e1mci v\u00fdzkumn\u00e9ho \u00fakolu pro objednatele Palivov\u00fd kombin\u00e1t \u00dast\u00ed, s. p. (obj. OV-13.65.00-18-0460). V\u00fdsledky studie byly prezentov\u00e1ny na konferenci SMART REGION F\u00d3RUM \u00dasteck\u00e9ho kraje SMART VODA (25. 4. 2019 Chomutov).<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Evaporation from free water surface is one of the important factors affecting the total water balance of a\u00a0catchment. Since direct measurement of evaporation is complicated, evaporation is in practice often calculated using formulas based on common meteorological variables.<\/p>\n","protected":false},"author":8,"featured_media":6638,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[1649,1651,1650],"coauthors":[124,35,27,1634],"class_list":["post-6640","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-evaporation-from-a-free-water-level","tag-hydric-recultivation","tag-total-runoff"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/6640","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=6640"}],"version-history":[{"count":2,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/6640\/revisions"}],"predecessor-version":[{"id":30531,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/6640\/revisions\/30531"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/6638"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=6640"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=6640"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=6640"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=6640"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}