{"id":4820,"date":"2018-06-11T09:20:04","date_gmt":"2018-06-11T08:20:04","guid":{"rendered":"https:\/\/www.vtei.cz\/?p=4820"},"modified":"2024-07-16T14:25:59","modified_gmt":"2024-07-16T13:25:59","slug":"water-balance-expression-of-the-amount-of-water-in-landscape","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2018\/06\/water-balance-expression-of-the-amount-of-water-in-landscape\/","title":{"rendered":"Water Balance \u2013 expression of the amount of water in landscape"},"content":{"rendered":"

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

 <\/p>\n

Souhrn<\/h2>\n

Pr\u016fb\u011bh po\u010das\u00ed v\u00a0posledn\u00edch letech dokl\u00e1d\u00e1, \u017ee prom\u011bnlivost na\u0161eho po\u010das\u00ed roste, a\u00a0t\u00edm se tak\u00e9 zvy\u0161uje frekvence v\u00fdskytu povodn\u00ed, ale tak\u00e9 sucha. Sucho bez ohledu na to, o\u00a0jak\u00fd druh se jedn\u00e1, znamen\u00e1, \u017ee v\u00a0na\u0161\u00ed krajin\u011b je nedostatek vody. Jde o\u00a0to, jak nejl\u00e9pe mno\u017estv\u00ed vody v\u00a0krajin\u011b vyj\u00e1d\u0159it. Na brn\u011bnsk\u00e9m pracovi\u0161ti \u010cesk\u00e9ho hydrometeorologick\u00e9ho \u00fastavu v\u00a0r\u00e1mci v\u00fdpo\u010detn\u00edho modelu AVISO v\u00a0t\u00fddenn\u00edm kroku vypo\u010d\u00edt\u00e1v\u00e1me z\u00e1kladn\u00ed vl\u00e1hovou bilanci (d\u00e1le jen ZVB) pro travn\u00ed porost, kter\u00e1 je d\u00e1na rozd\u00edlem mezi \u00fahrny sr\u00e1\u017eek a\u00a0potenci\u00e1ln\u00ed evapotranspirac\u00ed. V\u00fdpo\u010det je prov\u00e1d\u011bn z\u00a0denn\u00edch hodnot doby slune\u010dn\u00edho svitu, teploty a\u00a0vlhkosti vzduchu a\u00a0rychlosti v\u011btru. Z\u00e1kladem pro v\u00fdskyt mimo\u0159\u00e1dn\u00e9ho sucha jsou n\u00edzk\u00e9 \u00fahrny sr\u00e1\u017eek a\u00a0del\u0161\u00ed bezesr\u00e1\u017ekov\u00e1 obdob\u00ed, sv\u016fj vliv v\u0161ak maj\u00ed i\u00a0zvy\u0161uj\u00edc\u00ed se teploty vzduchu. Z\u00a0anal\u00fdzy vybran\u00fdch rok\u016f s\u00a0v\u00fdskytem mimo\u0159\u00e1dn\u00e9ho sucha vypl\u00fdv\u00e1, \u017ee deficitn\u00ed hodnoty vl\u00e1hov\u00e9 bilance se projevuj\u00ed v\u00a0jednotliv\u00fdch letech rozd\u00edln\u011b, koncem vegeta\u010dn\u00edho obdob\u00ed dosahuje deficit i\u00a0v\u00edce jak 200\u2008mm.<\/p>\n\"\"<\/a>\n

\u00davod<\/h2>\n

Podneb\u00ed \u010cesk\u00e9 republiky je typick\u00e9 svou vysokou prom\u011bnlivost\u00ed, kter\u00e1 se v\u00a0posledn\u00edch dvou desetilet\u00edch je\u0161t\u011b zvy\u0161uje. V\u00fdsledkem jsou tak\u00e9 v\u00fdskyty povodn\u00ed i\u00a0sucha, kter\u00e9 se na na\u0161em \u00fazem\u00ed projevuj\u00ed nepravideln\u011b. Zm\u011bn\u00e1m klimatu je p\u0159i\u010d\u00edt\u00e1no, \u017ee se zvy\u0161uj\u00ed \u010detnosti v\u00fdskytu extr\u00e9mn\u00edch stav\u016f po\u010das\u00ed. Jde o\u00a0mimo\u0159\u00e1dn\u011b vysok\u00e9 \u00fahrny sr\u00e1\u017eek a\u00a0n\u00e1sledn\u011b v\u00fdskyt plo\u0161n\u00fdch povodn\u00ed v\u00a0letech 1997, 2002 a\u00a0d\u00edky rychl\u00e9mu t\u00e1n\u00ed vysok\u00e9 sn\u011bhov\u00e9 pokr\u00fdvky i\u00a0v\u00a0roce 2006. V\u00a0roce 2010 byly zaznamen\u00e1ny vysok\u00e9 sr\u00e1\u017ekov\u00e9 \u00fahrny a\u00a0v\u00fdskyt mnoha lok\u00e1ln\u00edch povodn\u00ed z\u00a0p\u0159\u00edvalov\u00fdch de\u0161\u0165\u016f. V\u00a0posledn\u00edch dvou desetilet\u00edch\u00a0p\u0159eva\u017euj\u00ed stavy sucha, kter\u00e9 jsou vyvol\u00e1ny\u00a0n\u00edzk\u00fdmi \u00fahrny sr\u00e1\u017eek, hlavn\u011b\u00a0b\u011bhem tepl\u00e9ho p\u016flroku (duben a\u017e z\u00e1\u0159\u00ed) s\u00a0trv\u00e1n\u00edm od\u00a0n\u011bkolika t\u00fddn\u016f a\u017e po n\u011bkolik m\u011bs\u00edc\u016f. V\u00fdskyty mimo\u0159\u00e1dn\u00e9ho sucha tak\u0159ka na cel\u00e9m \u00fazem\u00ed \u010cR jsme zaznamenali v\u00a0letech 2000, 2003, 2012, 2015 a\u00a02017. Na ji\u017en\u00ed Morav\u011b tak\u00e9 v\u00a0roce 2007. Je nutn\u00e9 p\u0159ipomenout, \u017ee v\u00fdskyty sucha jsou u\u00a0n\u00e1s nahodil\u00e9, a\u00a0proto je velmi obt\u00ed\u017en\u00e9 jejich v\u00fdskyt p\u0159edpov\u00eddat. T\u00edmto se st\u00e1vaj\u00ed o\u00a0to \u0161kodliv\u011bj\u0161\u00ed, proto\u017ee p\u0159ich\u00e1zej\u00ed neo\u010dek\u00e1van\u011b v\u00a0r\u016fzn\u00fdch ro\u010dn\u00edch obdob\u00edch.<\/p>\n

\u00dadaje o\u00a0sr\u00e1\u017ek\u00e1ch jsou zaznamen\u00e1v\u00e1ny na sr\u00e1\u017ekom\u011brn\u00fdch stanic\u00edch \u010cesk\u00e9ho hydrometeorologick\u00e9ho \u00fastavu (d\u00e1le jen \u010cHM\u00da), v\u00a0posledn\u00edch letech p\u0159ev\u00e1\u017en\u011b na automatick\u00fdch stanic\u00edch [1]. Pr\u016fm\u011brn\u00e9 \u00fahrny sr\u00e1\u017eek se z\u00a0\u010d\u00e1sti li\u0161\u00ed podle obdob\u00ed zpracov\u00e1n\u00ed. V\u00a0Atlasu podneb\u00ed \u010ceskoslovenska (1958) a\u00a0Podneb\u00ed \u010cSSR \u2013 Tabulky (1960) jsou uvedeny v\u00fdstupy zpracov\u00e1n\u00ed za obdob\u00ed 1901 a\u017e 1950. Mapy \u00fahrn\u016f sr\u00e1\u017eek v\u00a0Atlasu podneb\u00ed \u010ceska [2] vyjad\u0159uj\u00ed obdob\u00ed 1961 a\u017e 2000. St\u0159e\u0161t\u00edk a\u00a0kol.\u00a0[3] vyhodnotili \u00fahrny sr\u00e1\u017eek na \u00fazem\u00ed \u010cR za obdob\u00ed 1961 a\u017e 2010\u2008s\u00a0v\u00fdsledkem, \u017ee v\u00a0dlouhodob\u00e9m pohledu se pr\u016fm\u011brn\u00e9 ro\u010dn\u00ed \u00fahrny sr\u00e1\u017eek statisticky prokazateln\u011b nem\u011bn\u00ed, ale roste jejich dynamika. K\u00a0hodnocen\u00ed sr\u00e1\u017eek za r\u016fzn\u00e1 obdob\u00ed, zvl\u00e1\u0161t\u011b za roky s\u00a0v\u00fdskyty povodn\u00ed \u010di sucha najdeme vysok\u00fd po\u010det publikac\u00ed.<\/p>\n

Sr\u00e1\u017ekov\u00fd deficit ve vegeta\u010dn\u00edm obdob\u00ed b\u00fdv\u00e1 velmi \u010dasto doprov\u00e1zen vysok\u00fdmi teplotami, v\u010detn\u011b v\u00fdskytu tropick\u00fdch dn\u016f (maxim\u00e1ln\u00ed denn\u00ed teplota vzduchu dos\u00e1hne \u010di p\u0159ekro\u010d\u00ed 30\u2008\u00b0C), ni\u017e\u0161\u00ed relativn\u00ed vlhkost\u00ed vzduchu, zmen\u0161enou obla\u010dnost\u00ed a\u00a0vy\u0161\u0161\u00edm po\u010dtem hodin slune\u010dn\u00edho svitu. Je zn\u00e1mo, \u017ee \u00fahrny sr\u00e1\u017eek jsou jedin\u00fdm zdrojem vody pro na\u0161i krajinu. Ov\u0161em p\u0159esto, \u017ee se pou\u017e\u00edv\u00e1 k\u00a0vyj\u00e1d\u0159en\u00ed sucha pouze \u00fahrn sr\u00e1\u017eek, nen\u00ed to zcela vhodn\u00e1 charakteristika.<\/p>\n

V\u00fdskyty sucha jsou d\u00e1ny tak\u00e9 hodnotami v\u00fdparu [4]. Jde o\u00a0slo\u017eit\u00fd fyzik\u00e1ln\u00ed proces a\u00a0pr\u00e1v\u011b to je p\u0159\u00ed\u010dinou, pro\u010d na rozd\u00edl od mnoha meteorologick\u00fdch prvk\u016f je m\u011b\u0159en\u00ed v\u00fdparu n\u00e1ro\u010dn\u00e9 [5]. \u00dadaje o\u00a0v\u00fdparu, ov\u0161em jen z\u00a0vodn\u00ed hladiny, m\u00e1me ze s\u00edt\u011b stanic \u010cesk\u00e9ho hydrometeorologick\u00e9ho \u00fastavu. Mimo tuto s\u00ed\u0165 je jen n\u011bkolik stanic, v\u011bt\u0161inou s\u00a0\u00fa\u010delov\u00fdm zam\u011b\u0159en\u00edm [6]. Ze srovn\u00e1n\u00ed nap\u0159. s\u00a0hodnotami evapotranspirace metodou FAO [7] vypl\u00fdv\u00e1, \u017ee vztah nen\u00ed jednozna\u010dn\u00fd\u00a0[8]. Pravideln\u00e9 m\u011b\u0159en\u00ed v\u00fdparu z\u00a0vodn\u00ed hladiny za\u0159\u00edzen\u00edm GGI-3000 bylo v\u00a0s\u00edti m\u011b\u0159ic\u00edch stanic zah\u00e1jeno v\u00a0roce 1968, podobn\u011b na Slovensku [9]. V\u00a0podstat\u011b do roku 2011 byly p\u0159\u00edstroje GGI-3000 nahrazeny automatick\u00fdmi v\u00fdparom\u011bry EWM [10]. Z\u00a0vyhodnocen\u00ed vypl\u00fdv\u00e1, \u017ee \u00fahrny v\u00fdparu a\u00a0jejich \u010dasov\u00e1 prom\u011bnlivost se v\u00a0jednotliv\u00fdch lokalit\u00e1ch dost li\u0161\u00ed, co\u017e je d\u00e1no prom\u011bnlivost\u00ed dal\u0161\u00edch meteorologick\u00fdch prvk\u016f [11]. Pr\u016fm\u011brn\u00fd denn\u00ed v\u00fdpar z\u00a0cel\u00e9 oblasti \u010cesk\u00e9 republiky z\u00a0obdob\u00ed 1971\u20132000 \u010dinil 2,6\u2008mm a\u00a0pr\u016fm\u011brn\u00fd \u00fahrn za vegeta\u010dn\u00ed sezonu V\u2013IX se rovnal 393,7\u2008mm. Pr\u016fm\u011brn\u00fd denn\u00ed v\u00fdpar z\u00a0oblasti ji\u017en\u00ed Moravy z\u00a0obdob\u00ed 1981\u20132010 \u010dinil 3,0\u2008mm a\u00a0pr\u016fm\u011brn\u00fd \u00fahrn za vegeta\u010dn\u00ed sezonu V\u2013IX se rovnal 462,3\u2008mm [10, 12].<\/p>\n\"\"<\/a>\n

Obr.\u00a01. Pod\u00edl sr\u00e1\u017ekov\u00e9ho \u00fahrnu za zimu 2014\/2015 vzhledem k\u00a0dlouhodob\u00e9mu pr\u016fm\u011bru 1961\u20132000
\nFig. 1. Ratio between precipitation amount and long-term average (1961\u20132000) for the 2014\/2015 winter<\/h6>\n

Bylo zji\u0161t\u011bno, \u017ee ro\u010dn\u00ed dynamika v\u00fdparu v\u00fdznamn\u011b kles\u00e1 s\u00a0r\u016fstem nadmo\u0159sk\u00e9 v\u00fd\u0161ky, podobn\u011b jako dlouhodob\u00e9 pr\u016fm\u011brn\u00e9 \u00fahrny v\u00fdparu, i\u00a0kdy\u017e z\u00a0tohoto pravidla existuj\u00ed v\u00fdjimky zp\u016fsoben\u00e9 dal\u0161\u00edmi \u010diniteli, jako zem\u011bpisn\u00e1 \u0161\u00ed\u0159ka nebo konkr\u00e9tn\u00ed lok\u00e1ln\u00ed podm\u00ednky geografick\u00e9ho prost\u0159ed\u00ed. B\u011bhem t\u0159icetilet\u00ed 1971\u20132000 pouze na dvou lokalit\u00e1ch sezonn\u00ed \u00fahrny v\u00fdparu maj\u00ed statisticky v\u00fdznamn\u00e9 r\u016fstov\u00e9 trendy, a\u00a0to v\u00a0Krom\u011b\u0159\u00ed\u017ei a\u00a0v\u00a0Holovousech. Zvy\u0161ov\u00e1n\u00ed v\u00fdparu se v\u00a0t\u011bchto lokalit\u00e1ch projevuje v\u00a0n\u00e1r\u016fstu 50 a\u017e 60\u2008mm za 10\u00a0let, co\u017e je v\u00fdrazn\u00e1 zm\u011bna pro procesy v\u00a0krajin\u011b [10]. Tento poznatek zcela neodpov\u00edd\u00e1 zji\u0161t\u011bn\u00ed, \u017ee pr\u016fm\u011brn\u00e9 teploty vzduchu maj\u00ed statisticky prokazateln\u00fd n\u00e1r\u016fst [13].<\/p>\n

S\u00a0ohledem na n\u00e1ro\u010dnost a\u00a0n\u00e1kladnost m\u011b\u0159en\u00ed v\u00fdparu a\u00a0jeho jednotliv\u00fdch druh\u016f jsou celosv\u011btov\u011b pou\u017e\u00edv\u00e1ny v\u00fdpo\u010dty evaporace a\u00a0evapotranspirace\u00a0[14,\u00a015]. Pr\u00e1v\u011b evapotranspirace t\u00edm, \u017ee bl\u00ed\u017ee vyjad\u0159uje v\u00fdpar z\u00a0porost\u016f, l\u00e9pe vyjad\u0159uje celkov\u00fd v\u00fdpar z\u00a0krajiny [16], ale je tak\u00e9 sou\u010d\u00e1st\u00ed v\u00fdpo\u010dt\u016f z\u00e1vlahov\u00fdch d\u00e1vek [15]. Pro ur\u010den\u00ed v\u00fdskytu \u010di intenzity sucha vyu\u017e\u00edv\u00e1me zjednodu\u0161enou, v\u00a0podstat\u011b meteorologickou, vodn\u00ed bilanci vyj\u00e1d\u0159enou vz\u00e1jemn\u00fdm rozd\u00edlem \u00fahrn\u016f sr\u00e1\u017eek a\u00a0potenci\u00e1ln\u00ed evapotranspirace. Ozna\u010dujeme ji jako z\u00e1kladn\u00ed (potenci\u00e1ln\u00ed) vl\u00e1hovou bilanci pro travn\u00ed porost (d\u00e1le jen ZVB_TP), kter\u00e1 sv\u00fdmi hodnotami umo\u017e\u0148uje hodnotit tak\u00e9 v\u00fdskyty sucha v\u00a0krajin\u011b [17]. Rozd\u00edl mezi potenci\u00e1ln\u00ed evapotranspirac\u00ed a\u00a0sr\u00e1\u017ekami je ukazatelem pro hodnocen\u00ed podoblast\u00ed v\u00a0r\u00e1mci agroklimatick\u00e9 rajonizace [18]. Takt\u00e9\u017e je sou\u010d\u00e1st\u00ed v\u00fdnosov\u00fdch model\u016f [19].<\/p>\n

Obecn\u011b lze \u0159\u00edci, \u017ee mno\u017estv\u00ed vody v\u00a0na\u0161\u00ed krajin\u011b je v\u00a0prvn\u00edm kroku d\u00e1no pr\u016fb\u011bhem po\u010das\u00ed, ale o\u00a0jej\u00edm dal\u0161\u00edm v\u00fdskytu v\u00fdznamn\u011b rozhoduj\u00ed vlastnosti na\u0161ich p\u016fd, zvl\u00e1\u0161t\u011b jejich reten\u010dn\u00ed kapacita [20].<\/p>\n

Materi\u00e1l a\u00a0metody<\/h2>\n

Meteorologick\u00e9 prvky nam\u011b\u0159en\u00e9 na klimatologick\u00fdch stanic\u00edch jsou z\u00e1kladem pro v\u00fdpo\u010dty prov\u00e1d\u011bn\u00e9 pomoc\u00ed agrometeorologick\u00e9ho modelu AVISO (\u201eAgrometeorologick\u00e1 V\u00fdpo\u010detn\u00ed a\u00a0Informa\u010dn\u00ed Soustava\u201c) na \u010cHM\u00da, pobo\u010dce Brno. Model je svou podstatou ur\u010den pro anal\u00fdzu p\u0159\u00edpad\u016f s\u00a0p\u0159evl\u00e1dajic\u00edm nedostatkov\u00fdm mno\u017estv\u00edm sr\u00e1\u017eek. Ne\u0159e\u0161\u00ed tedy problematiku nadbytku sr\u00e1\u017eek a\u00a0s\u00a0t\u00edm spojenou ot\u00e1zku odtoku. Z\u00a0tohoto pohledu se nask\u00fdt\u00e1 jeho uplatn\u011bn\u00ed pro anal\u00fdzu existuj\u00edc\u00edch such\u00fdch obdob\u00ed, resp. obdob\u00ed, kdy se vyskytuj\u00ed minim\u00e1ln\u00ed \u00fahrny sr\u00e1\u017eek.<\/p>\n

Evapotranspirace je modelov\u011b po\u010d\u00edt\u00e1na v\u00a0denn\u00edm kroku modifikovan\u00fdm postupem podle algoritm\u016f Penman-Montheith [21, 22]. Ve sv\u00e9 potenci\u00e1ln\u00ed podob\u011b je prakticky shodn\u00e1 s\u00a0maxim\u00e1ln\u011b mo\u017en\u00fdmi hodnotami v\u00fdparu p\u0159i optim\u00e1ln\u00edch vl\u00e1hov\u00fdch podm\u00ednk\u00e1ch, s\u00a0nimi\u017e se v\u00a0p\u0159\u00edrodn\u00edm prost\u0159ed\u00ed v\u011bt\u0161inou nesetk\u00e1v\u00e1me ve vegeta\u010dn\u00edm obdob\u00ed, resp. v\u00a0tepl\u00e9m p\u016flroce, ale podstatn\u011b \u010dast\u011bji v\u00a0zim\u011b nebo v\u00a0obdob\u00edch p\u0159echodn\u00fdch (jaro a\u00a0podzim).<\/p>\n\"\"<\/a>\n

Obr.\u00a02. Mapa srovn\u00e1n\u00ed \u00fahrn\u016f sr\u00e1\u017eek za obdob\u00ed 1. 1. a\u017e 13. 12. 2015\u2008s\u00a0pr\u016fm\u011brem za roky 1961\u20132000 vyj\u00e1d\u0159en\u00e9ho v\u00a0% (zdroj: \u010cHM\u00da)
\nFig. 2. Map comparing precipitation amount from Jan 1 to Dec 13, 2015 with the long-term average (1961\u20132000) expressed in % (source: CHMI)<\/h6>\n

ZVB_TP jednoduch\u00fdm zp\u016fsobem vyjad\u0159uje vl\u00e1hov\u00e9 pom\u011bry v\u00a0krajin\u011b za ur\u010dit\u00fd \u010dasov\u00fd interval. Po\u010d\u00edt\u00e1 se jako aritmetick\u00fd rozd\u00edl sr\u00e1\u017eek a\u00a0evapotranspirace (potenci\u00e1ln\u00ed, aktu\u00e1ln\u00ed, referen\u010dn\u00ed) za ur\u010dit\u00e9 \u010dasov\u00e9 obdob\u00ed, p\u0159i\u010dem\u017e ob\u011b slo\u017eky pro lep\u0161\u00ed vz\u00e1jemn\u00e9 srovn\u00e1n\u00ed se vyjad\u0159uj\u00ed v\u00a0mm. Pro zjednodu\u0161en\u00ed se neberou v\u00a0\u00favahu \u017e\u00e1dn\u00e9 ze slo\u017eek odtoku, stejn\u011b tak pro v\u00fdpo\u010det v\u00fdparu v\u00a0z\u00e1kladn\u00ed bilan\u010dn\u00ed rovnici uva\u017eujeme v\u00fdrazn\u00e9 zjednodu\u0161en\u00ed ve form\u011b homogenn\u00edho vypa\u0159uj\u00edc\u00edho povrchu, kter\u00fd je sv\u00fdmi fyziologick\u00fdmi vlastnostmi velmi bl\u00edzk\u00fd standardn\u00edmu travn\u00edmu porostu. Pokud bychom nep\u0159istoupili k\u00a0t\u011bmto zjednodu\u0161en\u00edm, problematika vl\u00e1hov\u00fdch bilanc\u00ed, kter\u00e1 je v\u00a0p\u0159\u00edrodn\u00edch podm\u00ednk\u00e1ch velmi n\u00e1ro\u010dn\u00e1 a\u00a0slo\u017eit\u00e1, by z\u00a0pohledu krajiny jako celku byla prakticky ne\u0159e\u0161iteln\u00e1. S\u00a0ohledem na p\u0159\u00edstupnost vody v\u00a0p\u016fd\u011b pro rostliny vyjad\u0159ujeme z\u00e1sobu vyu\u017eiteln\u00e9 vody v\u00a0<\/strong>metrov\u00e9 vrstv\u011b p\u016fdy s\u00a0travn\u00edm porostem (d\u00e1le jen ZVVP), kter\u00e1 je vypo\u010dtena p\u0159epo\u010dtem VVK v\u00a0% [23].<\/p>\n

V\u00fdsledky<\/h2>\n

Pr\u016fb\u011bh sucha v\u00a0jednotliv\u00fdch letech na na\u0161em \u00fazem\u00ed nen\u00ed zcela stejn\u00fd. Ji\u017e bylo uvedeno, \u017ee v\u00a0na\u0161ich podm\u00ednk\u00e1ch jde o\u00a0sucho nahodil\u00e9. Pokud jde o\u00a0rok 2012, v\u00fdrazn\u011b negativn\u00ed potenci\u00e1ln\u00ed vl\u00e1hov\u00e1 bilance byla zvl\u00e1\u0161t\u011b v\u00a0m\u011bs\u00edc\u00edch vegeta\u010dn\u00edho obdob\u00ed roku 2012. Srovn\u00e1n\u00edm s\u00a0dlouhodob\u00fdm obdob\u00edm let 1961\u20132010 nav\u00edc doch\u00e1z\u00edme k\u00a0z\u00e1v\u011br\u016fm zv\u00fd\u0161en\u00e9 negativn\u00ed potenci\u00e1ln\u00ed vl\u00e1hov\u00e9 bilance. Tato skute\u010dnost byla zaznamen\u00e1na i\u00a0p\u0159i hodnocen\u00ed pomoc\u00ed kumulovan\u00fdch \u00fahrn\u016f. Prokazateln\u00e9 je to hlavn\u011b na moravsk\u00fdch stanic\u00edch (Brno-Tu\u0159any, Kucha\u0159ovice) a\u00a0v\u00a0Doksanech, kdy proti dlouhodob\u00fdm m\u011bs\u00ed\u010dn\u00edm hodnot\u00e1m je situace v\u00a0roce 2012 o\u00a0v\u00edce ne\u017e 50\u2008mm hor\u0161\u00ed (kv\u011bten). Bereme-li v\u00a0\u00favahu kumulovan\u00e9 \u00fahrny po m\u011bs\u00edc\u00edch, pak ve vegeta\u010dn\u00edm obdob\u00ed je situace je\u0161t\u011b hor\u0161\u00ed, nebo\u0165 oproti dlouhodob\u00fdm pom\u011br\u016fm do vyrovnan\u00e9 potenci\u00e1ln\u00ed vl\u00e1hov\u00e9 bilance sch\u00e1z\u00ed i\u00a0v\u00edce ne\u017e 200\u2008mm (ji\u017en\u00ed Morava).<\/p>\n\"\"<\/a>\n

Obr.\u00a03. Z\u00e1kladn\u00ed vl\u00e1hov\u00e1 bilance \u00fazem\u00ed \u010cR (%), srovn\u00e1n\u00ed stavu od 1. 3. do 21. 5. 2017 k\u00a0dlouhodob\u00e9mu pr\u016fm\u011bru 1961 a\u017e 2010 (http:\/\/portal.chmi.cz\/aktualni-situace\/sucho#)
\nFig. 3. Basic water balance in the Czech Republic (%), comparison of values from Mar 1 to May 21, 2017 with the long-term average (1961\u20132010) (http:\/\/portal.chmi.cz\/aktualni-situace\/sucho#)<\/h6>\n

Zvl\u00e1\u0161t\u011b pro zem\u011bd\u011blsk\u00e9 porosty bylo negativn\u00ed, \u017ee v\u00a0posledn\u00edm t\u00fddnu kv\u011btna 2012 byl rozd\u00edl oproti dlouhodob\u00e9 hodnot\u011b -100\u2008mm a\u00a0byl ni\u017e\u0161\u00ed na v\u00edce jak 30\u00a0% \u00fazem\u00ed \u010cR. Nejv\u00edce jsou op\u011bt posti\u017eeny ji\u017en\u00ed a\u00a0st\u0159edn\u00ed Morava, d\u00e1le Polab\u00ed, \u010d\u00e1st Pooh\u0159\u00ed a\u00a0tak\u00e9 plo\u0161n\u011b velk\u00e9 oblasti jihoz\u00e1padn\u00edch \u010cech a\u00a0\u0160umavy. Vl\u00e1hovou bilanci pod -100\u2008mm u\u017e je mo\u017eno pova\u017eovat za mimo\u0159\u00e1dn\u00e9 sucho. Pod -150\u2008mm je na 3,5\u00a0% \u00fazem\u00ed, nejv\u00edce na ji\u017en\u00ed Morav\u011b, \u010d\u00e1sti \u0160umavy a\u00a0na P\u0159erovsku. Suchem v\u00a0roce 2012 byla nejv\u00edce zasa\u017eena ji\u017en\u00ed a\u00a0st\u0159edn\u00ed Morava a\u00a0v\u00fdrazn\u00e9 negativn\u00ed rozd\u00edly p\u0159etrv\u00e1valy i\u00a0v\u00a0Polab\u00ed a\u00a0na\u00a0\u0160umav\u011b. Na v\u011bt\u0161in\u011b \u00fazem\u00ed byla negativn\u00ed vl\u00e1hov\u00e1 bilance je\u0161t\u011b koncem z\u00e1\u0159\u00ed a\u00a0m\u00edsty p\u0159ekra\u010dovala hodnoty -200\u2008mm.<\/p>\n

Bylo by chybou posuzovat sucho samostatn\u011b jen v\u00a0ur\u010dit\u00fdch m\u011bs\u00edc\u00edch. Jeho v\u00fdvoj je ovliv\u0148ov\u00e1n i\u00a0pr\u016fb\u011bhem po\u010das\u00ed v\u00a0zim\u011b. Dokladem je v\u00fdskyt sucha v\u00a0roce 2015. Zima 2014\/2015 jako celek byla oproti pr\u016fm\u011bru na cel\u00e9m \u00fazem\u00ed teplej\u0161\u00ed, a\u00a0to o\u00a01,5 a\u017e 3,5\u2008\u00b0C. Deficit sr\u00e1\u017eek dosahoval a\u017e 50\u00a0%, na n\u011bkter\u00fdch \u010d\u00e1stech ji\u017en\u00ed Moravy a\u00a0na v\u011bt\u0161\u00ed \u010d\u00e1sti \u010cech. Jen na \u010d\u00e1stech severn\u00ed a\u00a0v\u00fdchodn\u00ed Moravy byl o\u00a0n\u011bco vy\u0161\u0161\u00ed ne\u017e pr\u016fm\u011br (obr.\u00a01<\/em>). V\u00a0pr\u016fb\u011bhu m\u011bs\u00edc\u016f dubna a\u017e \u010dervna byly \u00fahrny sr\u00e1\u017eek na v\u011bt\u0161in\u011b na\u0161eho \u00fazem\u00ed podnorm\u00e1ln\u00ed, tak\u017ee koncem kv\u011btna v\u00a0p\u00e1su od Karlov\u00fdch Var\u016f p\u0159es st\u0159edn\u00ed \u010cechy a\u017e k\u00a0\u010cesk\u00fdm Bud\u011bjovic\u00edm se jejich \u00fahrn pohybuje mezi 50 a\u017e 75\u00a0% pr\u016fm\u011bru. Obdobn\u011b je to na ji\u017en\u00ed a\u00a0\u010d\u00e1sti st\u0159edn\u00ed Moravy. Tento stav se v\u00a0\u010dervnu m\u011bn\u00ed tak, \u017ee v\u00a0Podkru\u0161noho\u0159\u00ed doch\u00e1z\u00ed k\u00a0dorovn\u00e1n\u00ed pr\u016fm\u011bru, naopak na Morav\u011b se zvy\u0161uje plocha \u00fazem\u00ed s\u00a0deficitem sr\u00e1\u017eek mezi 25 a\u017e 50\u00a0%. Mimo\u0159\u00e1dn\u011b n\u00edzk\u00e9 \u00fahrny sr\u00e1\u017eek v\u00a0\u010dervenci zp\u016fsobuj\u00ed, \u017ee na v\u011bt\u0161in\u011b na\u0161eho \u00fazem\u00ed byl deficit 25 a\u017e 50\u00a0%. Na n\u011bkolika m\u00edstech, hlavn\u011b v\u00a0oblasti ji\u017en\u00ed Moravy, je sr\u00e1\u017ekov\u00fd deficit v\u00edce jak 50\u00a0%. Ov\u0161em d\u00edky bou\u0159k\u00e1m jsou na t\u011bchto \u00fazem\u00edch lokality, kde deficit sr\u00e1\u017eek poklesl. Prohlubuj\u00edc\u00ed se deficit v\u00a0srpnu zastavily a\u017e sr\u00e1\u017eky od 16. srpna. Na obr.\u00a02<\/em> je srovn\u00e1n\u00ed \u00fahrn\u016f sr\u00e1\u017eek od 1. 1. do 13. 12. 2015\u2008s\u00a0pr\u016fm\u011brem za roky 1961 a\u017e 2000 v\u00a0procentech.<\/p>\n

D\u00edky t\u011bmto podm\u00ednk\u00e1m dosahovaly hodnoty z\u00e1kladn\u00ed vl\u00e1hov\u00e9 bilance v\u00a0b\u0159eznu pr\u016fm\u011brn\u00fdch hodnot, tomuto odpov\u00eddala i\u00a0ZVVP v\u00a0p\u016fdn\u00edm horizontu. Pr\u016fb\u011bh teplot vzduchu v\u00a0dubnu vyvol\u00e1val zv\u00fd\u0161en\u00ed hodnot evapotranspirace asi na polovin\u011b \u00fazem\u00ed \u010cech o\u00a020 %, ale m\u00edsty a\u017e o\u00a0v\u00edce ne\u017e 40\u00a0%. V\u00fdskyt tropick\u00fdch veder zvy\u0161uje deficit tak, \u017ee ke dni 12. 7. jsou m\u00edsta, kde z\u00e1kladn\u00ed vl\u00e1hov\u00e1 bilance m\u00e1 hodnoty pod -150\u2008mm. Tento stav je po cel\u00fd \u010dervenec s\u00a0t\u00edm, \u017ee nehomogenitu tohoto pole zp\u016fsobuj\u00ed lok\u00e1ln\u00ed bou\u0159ky. Ov\u0161em jejich ojedin\u011bl\u00fd v\u00fdskyt neovliv\u0148uje celkovou vl\u00e1hovou bilanci, tak\u017ee v\u00a0polovin\u011b srpna p\u0159ekra\u010duje na asi \u010dtvrtin\u011b na\u0161eho \u00fazem\u00ed deficit hodnoty -200\u2008mm. P\u0159es v\u00fdskyt sr\u00e1\u017eek byly projevy zem\u011bd\u011blsk\u00e9ho sucha na p\u0159ev\u00e1\u017en\u00e9 \u010d\u00e1sti na\u0161eho \u00fazem\u00ed je\u0161t\u011b v\u00a0\u0159\u00edjnu. Na severn\u00ed Morav\u011b potom a\u017e do konce roku 2015.<\/p>\n\"\"<\/a>\n

Obr.\u00a04. Z\u00e1kladn\u00ed vl\u00e1hov\u00e1 bilance \u00fazem\u00ed \u010cR (%), srovn\u00e1n\u00ed stavu od 1. 3. do 30. 7. 2017 k\u00a0dlouhodob\u00e9mu pr\u016fm\u011bru 1961 a\u017e 2010 (http:\/\/portal.chmi.cz\/aktualni-situace\/sucho#)
\nFig. 4. Basic water balance in the Czech Republic (%), comparison of values from Mar 1 to Jul 30, 2017 with the long-term average (1961\u20132010) (http:\/\/portal.chmi.cz\/aktualni-situace\/sucho#)<\/h6>\n

Jako mimo\u0159\u00e1dn\u011b such\u00fd se op\u011bt projevil na mnoha m\u00edstech na\u0161eho \u00fazem\u00ed i\u00a0rok 2017. Jak ji\u017e bylo mnohokr\u00e1t uvedeno, z\u00e1kladem obsahu vody v\u00a0p\u016fd\u011b pro po\u010d\u00e1tek vegeta\u010dn\u00edho obdob\u00ed jsou stavy po\u010das\u00ed v\u00a0pr\u016fb\u011bhu zimy. Pokud jde o\u00a0sr\u00e1\u017eky, byly tyto za m\u011bs\u00edce leden a\u017e b\u0159ezen na p\u0159ev\u00e1\u017en\u00e9 \u010d\u00e1sti \u00fazem\u00ed Moravy, ji\u017en\u00edch a\u00a0v\u00fdchodn\u00edch \u010cech v\u00a0rozp\u011bt\u00ed 50 a\u017e 75\u00a0% dlouhodob\u00e9ho pr\u016fm\u011bru, tedy podpr\u016fm\u011brn\u00e9. Na p\u0159ev\u00e1\u017en\u00e9 \u010d\u00e1sti \u010cech potom \u010dinily 75 a\u017e 90\u00a0%, na n\u011bkter\u00fdch m\u00edstech odpov\u00eddaly dlouhodob\u00e9mu pr\u016fm\u011bru. Ov\u0161em d\u00edky nadpr\u016fm\u011brn\u00fdm hodnot\u00e1m teploty vzduchu dosahuje potenci\u00e1ln\u00ed evapotranspirace v\u00a0b\u0159eznu na tak\u0159ka cel\u00e9m \u00fazem\u00ed Moravy a\u00a0Slezska p\u0159es 140\u00a0% oproti dlouhodob\u00e9mu pr\u016fm\u011bru a\u00a0v\u00a0\u010cech\u00e1ch je to na v\u00edce jak polovin\u011b \u00fazem\u00ed, jde p\u0159ev\u00e1\u017en\u011b o\u00a0st\u0159edn\u00ed a\u00a0v\u00fdchodn\u00ed \u010d\u00e1st \u010cech. ZVB_TP je za b\u0159ezen tak\u0159ka na cel\u00e9m \u00fazem\u00ed v\u00a0rozp\u011bt\u00ed od nuly po -50\u2008mm.<\/p>\n

Jestli\u017ee bereme duben jako prvn\u00ed m\u011bs\u00edc vegeta\u010dn\u00edho obdob\u00ed, potvrzuje se, \u017ee na ji\u017en\u00ed Morav\u011b je duben \u010dasto such\u00fd. Plo\u0161n\u00e1 rozd\u00edlnost projev\u016f po\u010das\u00ed se v\u00a0dubnu potvrdila. D\u00edky nepravideln\u00e9mu rozlo\u017een\u00ed sr\u00e1\u017eek,\u00a0m\u00edsty velmi n\u00edzk\u00e9mu, doch\u00e1z\u00ed v\u00a0pr\u016fb\u011bhu kv\u011btna k\u00a0velk\u00fdm rozd\u00edl\u016fm v\u00a0hodnot\u00e1ch ZVB_TP. Je to d\u00e1no oproti pr\u016fm\u011bru vy\u0161\u0161\u00ed potenci\u00e1ln\u00ed evapotranspirac\u00ed na p\u0159ev\u00e1\u017en\u00e9 \u010d\u00e1sti na\u0161eho \u00fazem\u00ed, m\u00edsty p\u0159esahuj\u00edc\u00ed 140\u00a0% dlouhodob\u00e9ho pr\u016fm\u011bru. Nach\u00e1z\u00edme m\u00edsta se sr\u00e1\u017ekami k\u00a0150\u00a0% a\u00a0naopak pouze k\u00a050\u00a0% procent\u016fm oproti pr\u016fm\u011bru.<\/p>\n

P\u0159itom dostatek vody m\u00e1 pro v\u011bt\u0161inu zem\u011bd\u011blsk\u00fdch plodin rozhoduj\u00edc\u00ed v\u00fdznam. Jak vid\u00edme na obr.\u00a03<\/em>, doch\u00e1z\u00ed v\u00a0prvn\u00edch t\u0159ech t\u00fddnech kv\u011btna 2017 k\u00a0deficitu ZVB_TP a\u017e k\u00a0-100\u2008mm na n\u011bkter\u00fdch m\u00edstech ji\u017en\u00ed a\u00a0severn\u00ed Moravy. V\u00a0\u010cech\u00e1ch je od Podkru\u0161noho\u0159\u00ed p\u0159es severn\u00ed oblasti a\u017e po v\u00fdchodn\u00ed \u010cechy stav mezi pr\u016fm\u011brem a\u017e -50\u2008mm. Naopak od Prahy na jih a\u00a0na severn\u00ed Morav\u011b je bilance kladn\u00e1\"\"<\/a><\/p>\n

Obr.\u00a05. Rozlo\u017een\u00ed \u00fahrn\u016f sr\u00e1\u017eek na \u00fazem\u00ed \u010cR za obdob\u00ed 1. ledna a\u017e 1. \u0159\u00edjna 2017 (http:\/\/portal.chmi.cz\/aktualni-situace\/sucho#)
\nFig. 5. Precipitation distribution in the Czech Republic from Jan 1 to Oct 1, 2017 (http:\/\/portal.chmi.cz\/aktualni-situace\/sucho#)<\/h6>\n

Nadpr\u016fm\u011brn\u00e9 teploty v\u00a0pr\u016fb\u011bhu \u010dervna a\u00a0velmi rozd\u00edln\u00e9, ale p\u0159ev\u00e1\u017en\u011b podpr\u016fm\u011brn\u00e9 \u00fahrny sr\u00e1\u017eek v\u0161ak zp\u016fsobuj\u00ed, \u017ee koncem \u010dervna jsou m\u00edsty hodnoty ZVB_TP na jihu Moravy, ale i\u00a0\u010cech pod -100\u2008mm, lok\u00e1ln\u011b pod -150. Na ji\u017en\u00ed a\u00a0st\u0159edn\u00ed \u010d\u00e1sti Moravy maj\u00ed hodnoty pod 25\u00a0%, podobn\u011b jako d\u00edl\u010d\u00ed \u00fazem\u00ed v\u00a0Podkru\u0161noho\u0159\u00ed. Naopak st\u0159edn\u00ed \u010cechy v\u00a0p\u00e1su a\u017e ke Krkono\u0161\u00edm maj\u00ed hodnoty pr\u016fm\u011brn\u00e9, m\u00edsty a\u017e n\u011bkolik des\u00edtek nad dlouhodob\u00fdm pr\u016fm\u011brem. V\u00a0\u010dervenci jsou sr\u00e1\u017eky srovnateln\u00e9 s\u00a0pr\u016fm\u011brem na v\u011bt\u0161in\u011b \u00fazem\u00ed. Teploty vzduchu jsou vy\u0161\u0161\u00ed od 1\u2008\u00b0C a\u017e p\u0159es 2\u2008\u00b0C na jihu Moravy. T\u00edm je d\u00e1no, \u017ee na v\u011bt\u0161in\u011b \u00fazem\u00ed jsou hodnoty ZVB pod -100\u2008mm. Na p\u0159ev\u00e1\u017en\u00e9 \u010d\u00e1sti ji\u017en\u00ed a\u00a0st\u0159edn\u00ed Moravy a\u00a0v\u00a0ji\u017en\u00edch \u010cech\u00e1ch jsou ni\u017e\u0161\u00ed jak -150, lok\u00e1ln\u011b na ji\u017en\u00ed Morav\u011b pod -200\u2008mm. Ov\u0161em v\u00a0n\u011bkter\u00fdch oblastech, zvl\u00e1\u0161t\u011b na severu Moravy je ZVB_TP v\u00a0hodnot\u00e1ch pr\u016fm\u011bru. Lok\u00e1ln\u011b jsou tyto hodnoty i\u00a0v\u00a0\u010cech\u00e1ch (obr.\u00a04<\/em>).<\/p>\n

Srpen m\u00e1 \u00fahrny sr\u00e1\u017eek v\u00fdznamn\u011b rozd\u00edln\u00e9 v\u00a0\u010cech\u00e1ch, kde jsou nap\u0159. na z\u00e1pad\u011b, ale i\u00a0v\u00a0ji\u017en\u00edch \u010cech\u00e1ch a\u017e o\u00a050\u00a0% vy\u0161\u0161\u00ed ne\u017e pr\u016fm\u011brn\u00e9, ov\u0161em na v\u011bt\u0161in\u011b \u00fazem\u00ed Moravy a\u00a0Slezska je to jen mezi 50 a\u017e 70\u00a0%. Ale teploty vzduchu jsou zde vy\u0161\u0161\u00ed o\u00a0v\u00edce ne\u017e 2\u2008\u00b0C nad pr\u016fm\u011brem, kde\u017eto na z\u00e1pad\u011b \u010cech je to jen do +1,5\u2008\u00b0C. V\u00fdsledek je jasn\u00fd. Hodnoty potenci\u00e1ln\u00ed evapotranspirace jsou na p\u0159ev\u00e1\u017en\u00e9 \u010d\u00e1sti republiky nadpr\u016fm\u011brn\u00e9.<\/p>\n

M\u00ednusov\u00e9 hodnoty ZVB se prohlubuj\u00ed, tak\u017ee deficit ni\u017e\u0161\u00ed ne\u017e 200\u2008mm je na v\u011bt\u0161\u00edch ploch\u00e1ch, maj\u00ed ho lokality na st\u0159edn\u00ed i\u00a0severn\u00ed Morav\u011b. Hodnoty pod -150\u2008mm nach\u00e1z\u00edme v\u00a0cel\u00e9 ji\u017en\u00ed \u010d\u00e1sti republiky, ale tak\u00e9 na Karlovarsku. Pokud jde o\u00a0ZVVP, je v\u00edcem\u00e9n\u011b stejn\u00e1 situace jako v\u00a0\u010dervnu, tedy na ji\u017en\u00ed a\u00a0st\u0159edn\u00ed<\/p>\n

Morav\u011b jsou hodnoty st\u00e1le pod 25\u00a0%, podobn\u011b jako d\u00edl\u010d\u00ed \u00fazem\u00ed v\u00a0Podkru\u0161noho\u0159\u00ed a\u00a0na jihov\u00fdchod od Plzn\u011b. M\u00edrn\u011b se zmen\u0161ila oblast s\u00a0pr\u016fm\u011brnou hodnotou ve st\u0159edn\u00edch \u010cech\u00e1ch, ale v p\u00e1su u\u00a0Podkrkono\u0161\u00ed z\u016fst\u00e1vaj\u00ed m\u00edsta s\u00a0hodnotami ZVVP u\u00a0st\u0159edn\u00edch p\u016fd a\u017e n\u011bkolik des\u00edtek % nad dlouhodob\u00fdm pr\u016fm\u011brem. Podobn\u011b je tomu v\u00a0oblasti Jesen\u00edk\u016f a\u00a0severov\u00fdchodn\u00edch Beskyd.<\/p>\n

V\u00fdskyt vydatn\u00fdch sr\u00e1\u017eek na\u00a0po\u010d\u00e1tku z\u00e1\u0159\u00ed z\u00a0\u010d\u00e1sti sn\u00ed\u017eil vl\u00e1hov\u00fd deficit. Tak\u0159ka na t\u0159etin\u011b \u00fazem\u00ed \u010cech byl v\u00a0polovin\u011b z\u00e1\u0159\u00ed dosa\u017een, pop\u0159. i\u00a0p\u0159ekro\u010den, dlouhodob\u00fd pr\u016fm\u011br sr\u00e1\u017ekov\u00fdch \u00fahrn\u016f k\u00a01. 10. 2018 (obr.\u00a05<\/em>). Na Morav\u011b pouze v\u00a0ji\u017en\u00ed a\u00a0st\u0159edn\u00ed \u010d\u00e1sti byly oblasti s\u00a0\u00fahrny mezi 50 a\u017e 75\u00a0% pr\u016fm\u011bru. Doch\u00e1z\u00ed tak ke zlep\u0161en\u00ed ZVB, kdy\u017e na severn\u00ed \u010d\u00e1sti \u010cech a\u00a0Moravy m\u00e1 hodnoty dlouhodob\u00e9ho pr\u016fm\u011bru. Ov\u0161em na ji\u017en\u00ed a\u00a0st\u0159edn\u00ed Morav\u011b, ale i\u00a0v\u00a0ji\u017en\u00edch \u010cech\u00e1ch jsou st\u00e1le katastry, kde chyb\u00ed v\u00edce jak 200\u2008mm. V\u00a0t\u011bchto je i\u00a0ZVVP n\u00edzk\u00e1, pohybuje se mezi 25 a\u017e 50\u00a0%. Tyto hodnoty nach\u00e1z\u00edme i\u00a0v\u00a0okol\u00ed Prahy. Pokra\u010duj\u00edc\u00ed v\u00fdskyty sr\u00e1\u017eek pozvolna vylep\u0161uj\u00ed mno\u017estv\u00ed vody v\u00a0p\u016fd\u011b v\u00a0konci vegeta\u010dn\u00edho obdob\u00ed, tedy koncem z\u00e1\u0159\u00ed. Jen na Morav\u011b se nach\u00e1z\u00ed n\u011bkolik m\u00edst, kde je v\u00fdskyt sr\u00e1\u017eek mezi 50 a\u017e 75\u00a0% pr\u016fm\u011bru. V\u00a0\u010cech\u00e1ch je na sever od Prahy v\u00fdskyt p\u0159es 100\u00a0%, podobn\u011b na severov\u00fdchod\u011b Moravy. Ov\u0161em ZVB_TP se zlep\u0161uje jen nepatrn\u011b, v\u00a0podstat\u011b se od poloviny z\u00e1\u0159\u00ed v\u00fdrazn\u011b nem\u011bn\u00ed.<\/p>\n

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

P\u0159i hodnocen\u00ed mno\u017estv\u00ed vody v\u00a0na\u0161\u00ed krajin\u011b mus\u00edme br\u00e1t v\u00a0\u00favahu, \u017ee extr\u00e9my ve v\u00fdskytu sr\u00e1\u017eek jsou v\u00a0posledn\u00edch letech st\u00e1le dynami\u010dt\u011bj\u0161\u00ed. Prokazateln\u00fd je r\u016fst teploty vzduchu za obdob\u00ed 1961 a\u017e 2010, ale naopak je statisticky potvrzen\u00fd setrval\u00fd stav ro\u010dn\u00edch \u00fahrn\u016f sr\u00e1\u017eek. Z\u00a0t\u011bchto poznatk\u016f vypl\u00fdv\u00e1, \u017ee se m\u016f\u017ee zvy\u0161ovat \u010detnost v\u00fdskyt\u016f sucha, co\u017e uveden\u00e1 hodnocen\u00ed dokl\u00e1daj\u00ed.<\/p>\n

Potvrzuje se, \u017ee hodnoty z\u00e1kladn\u00ed vl\u00e1hov\u00e9 bilance a\u00a0z\u00e1soby vyu\u017eiteln\u00e9 vody v\u00a0metrov\u00e9 vrstv\u011b p\u016fdy s\u00a0travn\u00edm porostem jsou vhodn\u00fdm ukazatelem ur\u010den\u00ed v\u00fdskytu sucha a\u00a0hodnocen\u00ed jeho intenzity. P\u0159edlo\u017een\u00e9 v\u00fdsledky potvrdily, \u017ee \u00fazem\u00ed \u010cR je z\u00a0hlediska vl\u00e1hov\u00e9 bilance velmi rozd\u00edln\u00e9. Vliv na toto rozlo\u017een\u00ed m\u00e1 prom\u011bnliv\u00fd v\u00fdskyt sr\u00e1\u017eek, ale tak\u00e9 hodnoty teploty vzduchu, kter\u00e9 jsou v\u00a0such\u00fdch letech, hlavn\u011b v\u00a0letn\u00edm obdob\u00ed, mimo\u0159\u00e1dn\u011b vysok\u00e9. Sucho m\u00e1 ur\u010dit\u00fd kumulativn\u00ed charakter, v\u00a0nep\u0159\u00edzniv\u00fdch podm\u00ednk\u00e1ch se jeho intenzita a\u00a0dopady s\u00a0ka\u017ed\u00fdm dnem zvy\u0161uj\u00ed. N\u00e1sledky potom mohou trvat dlouhou dobu po jeho ukon\u010den\u00ed.<\/p>\n

N\u00e1stupy sucha i\u00a0m\u00edsta v\u00fdskytu jsou v\u00a0z\u00e1vislosti na sr\u00e1\u017ek\u00e1ch prom\u011bnliv\u00e9, ale p\u0159esto m\u016f\u017eeme uv\u00e9st, \u017ee se sucho nej\u010dast\u011bji vyskytuje v\u00a0na\u0161ich nejteplej\u0161\u00edch oblastech s\u00a0nejni\u017e\u0161\u00edmi ro\u010dn\u00edmi \u00fahrny sr\u00e1\u017eek. Z\u00a0hlediska udr\u017een\u00ed sr\u00e1\u017ekov\u00e9 vody v\u00a0na\u0161\u00ed krajin\u011b jsou d\u016fle\u017eit\u00e9 vlastnosti na\u0161ich p\u016fd jak zem\u011bd\u011blsk\u00fdch, tak lesnick\u00fdch, na kter\u00fdch hlavn\u011b prob\u00edh\u00e1 vsakov\u00e1n\u00ed. Proto je d\u016fle\u017eit\u00e9 p\u0159ijet\u00ed opat\u0159en\u00ed pro zlep\u0161en\u00ed infiltra\u010dn\u00ed schopnosti a\u00a0zv\u00fd\u0161en\u00ed reten\u010dn\u00ed kapacity t\u011bchto p\u016fd do p\u016fvodn\u00edho stavu.<\/p>\n

Souvis\u00ed s\u00a0t\u00edm i\u00a0opat\u0159en\u00ed pro sn\u00ed\u017een\u00ed eroze p\u016fdy, proto\u017ee orni\u010dn\u00ed horizont m\u00e1 tuto kapacitu v\u00fdznamn\u011b vy\u0161\u0161\u00ed ne\u017e na erodovan\u00fdch p\u016fd\u00e1ch, kde horn\u00ed vrstvu tvo\u0159\u00ed podorni\u010d\u00ed. Zv\u00fd\u0161en\u00ed \u010dlenitosti na\u0161\u00ed krajiny p\u0159isp\u011bje ke sn\u00ed\u017een\u00ed odtoku vody.<\/p>\n

Podle v\u00fdsledk\u016f klimatologick\u00fdch model\u016f by mohlo doj\u00edt ke vzr\u016fstu pr\u016fm\u011brn\u00fdch ro\u010dn\u00edch teplot koncem tohoto stolet\u00ed a\u017e o\u00a0v\u00edce ne\u017e dva stupn\u011b, ale sr\u00e1\u017ekov\u00e9 \u00fahrny budou v\u00edcem\u00e9n\u011b shodn\u00e9 se sou\u010dasn\u00fdmi. Z\u00a0toho plyne jeden v\u00fdznamn\u00fd poznatek, \u017ee na na\u0161em \u00fazem\u00ed by se mohly v\u00fdznamn\u011b sni\u017eovat hodnoty vl\u00e1hov\u00e9 bilance, a\u00a0to znamen\u00e1 zvy\u0161ov\u00e1n\u00ed jak intenzity, tak \u010detnost\u00ed v\u00fdskytu sucha. Pro sn\u00ed\u017een\u00ed negativn\u00edch dopad\u016f zm\u011bn klimatu bychom m\u011bli konat preventivn\u00ed kroky, aby se nedostatek vody nestal bezpe\u010dnostn\u00edm rizikem.<\/p>\n

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

P\u0159\u00edsp\u011bvek byl vypracov\u00e1n s\u00a0podporou projektu NAZV registra\u010dn\u00ed \u010d\u00edslo QK1720285 \u201eMetody korekce vl\u00e1hov\u00fdch pot\u0159eb plodin zohled\u0148uj\u00edc\u00ed sc\u00e9n\u00e1\u0159e zm\u011bn klimatu \u00fazem\u00ed \u010cR pro optimalizaci managementu z\u00e1vlah\u201c.<\/em><\/p>\n

Tento \u010dl\u00e1nek byl zpracov\u00e1n na z\u00e1klad\u011b p\u0159\u00edsp\u011bvku, kter\u00fd byl publikov\u00e1n ve sborn\u00edku konference Vodn\u00ed n\u00e1dr\u017ee 2017, ISBN 978-80-905368-5-2.<\/p>\n","protected":false},"excerpt":{"rendered":"

Course of the weather in the last years shows that variability of the weather increases and this also leads to a higher frequency of floods, as well as drought. Drought, regardless of its type, means that there is a lack of water in landscape. <\/p>\n","protected":false},"author":8,"featured_media":4857,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[91,86],"tags":[121,1237,1236,870],"coauthors":[1202,1204,1205,1206],"class_list":["post-4820","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-applied-ecology","category-hydraulics-hydrology-and-hydrogeology","tag-drought","tag-potential-evapotranspiration","tag-precipitation-amount","tag-water-balance"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/4820","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=4820"}],"version-history":[{"count":2,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/4820\/revisions"}],"predecessor-version":[{"id":30460,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/4820\/revisions\/30460"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/4857"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=4820"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=4820"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=4820"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=4820"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}