{"id":6242,"date":"2019-04-11T09:43:59","date_gmt":"2019-04-11T08:43:59","guid":{"rendered":"https:\/\/www.vtei.cz\/?p=6242"},"modified":"2024-07-16T15:18:40","modified_gmt":"2024-07-16T14:18:40","slug":"urceni-rozsahu-pudy-nechranene-vegetaci-v-obdobi-privalovych-srazek-za-ucelem-posouzeni-erozniho-rizika","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2019\/04\/urceni-rozsahu-pudy-nechranene-vegetaci-v-obdobi-privalovych-srazek-za-ucelem-posouzeni-erozniho-rizika\/","title":{"rendered":"Determination of the extent of soil unprotected by vegetation in the period of rainstorms to assess erosion risk"},"content":{"rendered":"<h4>This article is available in Czech only. For translation or more information on this topic, please contact author.<\/h4>\n<p>&nbsp;<\/p>\n<h2>Souhrn<\/h2>\n<p>\u010cl\u00e1nek popisuje metodu, zdrojov\u00e1 data i\u00a0v\u00fdsledky anal\u00fdzy erozn\u00ed ohro\u017eenosti podle nov\u00e9 metodiky vyu\u017eit\u00ed d\u00e1lkov\u00e9ho pr\u016fzkumu Zem\u011b pro ochranu zem\u011bd\u011blsk\u00e9 p\u016fdy. Metoda je testov\u00e1na na pozemc\u00edch AGRA \u0158isuty, s. r. o. Pro zji\u0161t\u011bn\u00ed p\u0159\u00edtomnosti vegeta\u010dn\u00edho pokryvu na jednotliv\u00fdch p\u016fdn\u00edch bloc\u00edch \u010di jejich \u010d\u00e1stech jsou vyu\u017e\u00edv\u00e1na data z\u00a0dru\u017eic Landsat 8 a\u00a0Sentinel 2. D\u00e1le jsou pou\u017eita existuj\u00edc\u00ed data zem\u011bd\u011blsk\u00e9ho podniku o\u00a0evidenci term\u00edn\u016f agrotechnick\u00fdch postup\u016f pro tvorbu kalibra\u010dn\u00edch polygon\u016f a\u00a0v\u00fdpo\u010det faktoru ochrann\u00e9ho \u00fa\u010dinku vegetace. Dru\u017eicov\u00e9 sc\u00e9ny jsou z\u00edsk\u00e1v\u00e1ny ze serveru Land Viewer a\u00a0zpracov\u00e1v\u00e1ny v\u00a0GIS. Slou\u010den\u00edm zpracovan\u00fdch dat vznikaj\u00ed mapy k\u00a0dal\u0161\u00ed anal\u00fdze, a\u00a0je tak z\u00edsk\u00e1n p\u0159ehled o\u00a0pozemc\u00edch a\u00a0jejich p\u0159edpokl\u00e1dan\u00e9m a\u00a0re\u00e1ln\u00e9m ohro\u017een\u00ed vodn\u00ed eroz\u00ed.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Ilustracni-4.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"981\" class=\"alignnone size-full wp-image-6148 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Ilustracni-4.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Ilustracni-4.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Ilustracni-4-245x300.jpg 245w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Ilustracni-4-768x942.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/981;\" \/><\/a>\n<p>Pozemky o\u00a0celkov\u00e9 plo\u0161e p\u0159esahuj\u00edc\u00ed 1 500\u2008ha byly sledov\u00e1ny po obdob\u00ed t\u0159\u00ed vegeta\u010dn\u00edch sezon (2015\u20132017). Nejrizikov\u011bj\u0161\u00ed byl rok 2015, kdy se hol\u00e9 p\u016fdy vyskytovaly a\u017e na 1 000\u2008ha b\u011bhem obdob\u00ed \u010dervence a\u00a0srpna. V\u00fdznamn\u00fdm faktorem pro v\u00fdskyt hol\u00fdch p\u016fd v\u00a0obdob\u00ed v\u00fdskytu erozn\u011b \u00fa\u010dinn\u00fdch sr\u00e1\u017eek na pozemc\u00edch AGRA \u0158isuty je v\u00fdsev \u0159epky ozim\u00e9.<\/p>\n<p>\u00daskal\u00edm p\u0159\u00edstupu je st\u00e1le n\u00edzk\u00e1 dostupnost bezobla\u010dn\u00fdch dru\u017eicov\u00fdch sc\u00e9n pro obdob\u00ed n\u00e1stupu p\u0159\u00edvalov\u00fdch sr\u00e1\u017eek a\u00a0rychl\u00e9ho rozvoje vegeta\u010dn\u00edho pokryvu v\u00a0rizikov\u00e9m obdob\u00ed \u010derven\u2013srpen. Dal\u0161\u00ed nejistotu do anal\u00fdzy vn\u00e1\u0161\u00ed identifikace p\u016fdy nezakryt\u00e9 vegetac\u00ed v\u00a0obdob\u00ed vysok\u00e9 zralosti p\u011bstovan\u00fdch plodin, v\u00a0tomto obdob\u00ed je nutn\u00e9 konfrontovat v\u00fdsledky s\u00a0datem na\u010dasov\u00e1n\u00ed sklizn\u00ed jednotliv\u00fdch p\u016fdn\u00edch blok\u016f.<\/p>\n<p>Metoda se jev\u00ed jako vhodn\u00e1 pro vyu\u017eit\u00ed jednotliv\u00fdmi zem\u011bd\u011blsk\u00fdmi podniky, p\u0159i\u010dem\u017e nejistota p\u0159i ur\u010dov\u00e1n\u00ed p\u016fdn\u00edho pokryvu je d\u00e1le redukov\u00e1na snadnou dostupnost\u00ed kalibra\u010dn\u00edch dat z\u00a0ter\u00e9nu a\u00a0jednoduch\u00fdm p\u0159\u00edstupem ke skliz\u0148ov\u00fdm dat\u016fm. Vypu\u0161t\u011bn\u00edm dru\u017eice Sentinel 2\u2008B v\u00a0roce 2017 se tak\u00e9 zlep\u0161ila dostupnost dostate\u010dn\u00e9ho mno\u017estv\u00ed dat v\u00a0ucelen\u00fdch \u010dasov\u00fdch \u0159ad\u00e1ch.<\/p>\n<h2>\u00davod<\/h2>\n<p>V\u00a0sou\u010dasn\u00e9 dob\u011b je trendem optimalizace v\u00fdnos\u016f v\u00a0zem\u011bd\u011blstv\u00ed pomoc\u00ed metod precizn\u00edho zem\u011bd\u011blstv\u00ed a\u00a0sledov\u00e1n\u00ed prostorov\u00e9ho rozlo\u017een\u00ed v\u00fdnos\u016f v\u00a0r\u00e1mci p\u016fdn\u00edch blok\u016f. Na z\u00e1klad\u011b posouzen\u00ed dlouhodob\u00fdch r\u016fstov\u00fdch charakteristik je mo\u017eno c\u00edlen\u011b aplikovat hnojiva, ale t\u00e9\u017e ochrann\u00e9 post\u0159iky, a\u00a0to jak z\u00a0d\u016fvodu ekonomick\u00fdch \u00faspor, tak za \u00fa\u010delem dal\u0161\u00edho zvy\u0161ov\u00e1n\u00ed v\u00fdnos\u016f a\u00a0zisku. Z\u00e1rove\u0148 jsou v\u0161ak v\u00a0\u010cesk\u00e9 republice zem\u011bd\u011blsk\u00e9 pozemky vystavov\u00e1ny riziku degradace p\u016fdy vlivem vodn\u00ed eroze, kter\u00e1 se krom\u011b zn\u00e1m\u00fdch negativn\u00edch efekt\u016f pro vodu a\u00a0p\u016fdu pod\u00edl\u00ed i\u00a0na p\u0159\u00edpadn\u00e9m sni\u017eov\u00e1n\u00ed v\u00fdnos\u016f (po\u0161kozen\u00ed osiva, vzrostl\u00fdch plodin, sn\u00ed\u017een\u00ed \u00farodnosti p\u016fdy apod.). Prostorov\u011b spr\u00e1vn\u00e9 posouzen\u00ed erozn\u00edho rizika je tedy pot\u0159ebn\u00e9 jednak pro ochranu p\u016fdy, ale rovn\u011b\u017e pro zlep\u0161en\u00ed zem\u011bd\u011blsk\u00e9 produkce, co\u017e je v\u00a0souladu s\u00a0c\u00edli nejen precizn\u00edho zem\u011bd\u011blstv\u00ed.<\/p>\n<p>Metodika vyu\u017eit\u00ed voln\u011b dostupn\u00fdch dru\u017eicov\u00fdch dat pro sledov\u00e1n\u00ed prostorov\u00e9 distribuce r\u016fstu zem\u011bd\u011blsk\u00fdch plodin byla v\u00a0\u010cR publikov\u00e1na Lukasem [1]. Od roku 2015 jsou pak pro dopln\u011bn\u00ed \u010dasov\u00e9 \u0159ady a\u00a0omezen\u00ed probl\u00e9m\u016f s\u00a0obla\u010dnost\u00ed v\u00a0dru\u017eicov\u00fdch sc\u00e9n\u00e1ch k\u00a0dispozici krom\u011b dat z\u00a0programu Landsat (dru\u017eice Landsat 5, Landsat 7 a\u00a0Landsat 8) rovn\u011b\u017e data z\u00a0programu Copernicus (dru\u017eice Sentinel 2). Ta mohou v\u00fdrazn\u011b napomoci ke zkvalitn\u011bn\u00ed anal\u00fdz v\u00fdvoje vegeta\u010dn\u00edho r\u016fstu pomoc\u00ed vegeta\u010dn\u00edch index\u016f, zejm\u00e9na nej\u010dast\u011bji vyu\u017e\u00edvan\u00e9ho normalizovan\u00e9ho indexu NDVI. Dru\u017eice Sentinel 2\u2008A odstartovala v\u00a0\u010dervnu 2015, dru\u017eice Sentinel 2\u2008B v\u00a0b\u0159eznu 2017. Spole\u010dn\u011b tak poskytuj\u00ed \u010dasov\u00e9 rozli\u0161en\u00ed p\u0159ibli\u017en\u011b t\u0159i dny pro \u00fazem\u00ed \u010cR. Data Sentinelu 2 jsou z\u00edsk\u00e1v\u00e1na v\u00a0celkem 13 spektr\u00e1ln\u00edch kan\u00e1lech o\u00a0r\u016fzn\u00fdch vlnov\u00fdch d\u00e9lk\u00e1ch [2].<\/p>\n<p>B\u011b\u017en\u00fdm zp\u016fsobem hodnocen\u00ed erozn\u00edho rizika v\u00a0\u010cR, pou\u017e\u00edvan\u00fdm jak p\u0159i vymezen\u00ed rizikov\u00fdch ploch v\u00a0r\u00e1mci kontroly podm\u00edn\u011bnosti zem\u011bd\u011blsk\u00fdch dotac\u00ed, tak p\u0159i n\u00e1vrz\u00edch opat\u0159en\u00ed nap\u0159. v\u00a0pozemkov\u00fdch \u00faprav\u00e1ch, je posouzen\u00ed pomoc\u00ed Univerz\u00e1ln\u00ed rovnice ztr\u00e1ty p\u016fdy\u00a0\u2013 USLE [3\u20135]. Je obecnou shodou, \u017ee dlouhodob\u011b rizikov\u00e9 lokality lze p\u0159i dostate\u010dn\u011b podrobn\u00fdch vstupn\u00edch datech v\u00a0r\u00e1mci v\u00fdpo\u010dtu v\u00a0libovoln\u00e9m geografick\u00e9m informa\u010dn\u00edm syst\u00e9mu pomoc\u00ed metody USLE v\u00a0jej\u00ed prostorov\u011b distribuovan\u00e9 podob\u011b (USLE2D, USLE3D) identifikovat dostate\u010dn\u011b p\u0159esn\u011b [6]. Nicm\u00e9n\u011b re\u00e1ln\u00e9 erozn\u00ed riziko z\u00e1vis\u00ed krom\u011b v\u00fdskytu p\u0159\u00edvalov\u00e9 sr\u00e1\u017eky tak\u00e9 na vegeta\u010dn\u00edm pokryvu. Ten lze dlouhodob\u011b popsat pomoc\u00ed vyhodnocen\u00ed skute\u010dn\u00fdch osevn\u00edch postup\u016f [7], nicm\u00e9n\u011b v\u00a0konkr\u00e9tn\u00edm roce jej lze na rozs\u00e1hl\u00fdch ploch\u00e1ch nejrychleji odhadnout s\u00a0vyu\u017eit\u00edm v\u00fd\u0161e citovan\u00fdch dru\u017eicov\u00fdch dat.<\/p>\n<p>Zde se nab\u00edz\u00ed vyu\u017eit\u00ed dru\u017eicov\u00fdch sc\u00e9n nejen k\u00a0ur\u010den\u00ed pokryvnosti a\u00a0ochrann\u00e9ho \u00fa\u010dinku vegetace, ale rovn\u011b\u017e k\u00a0vymezen\u00ed zcela odkryt\u00fdch p\u016fd a\u00a0v\u00fdvoje poklesu zastoupen\u00ed hol\u00e9 p\u016fdy na povod\u00edch i\u00a0na konkr\u00e9tn\u00edch pozemc\u00edch b\u011bhem vegeta\u010dn\u00ed sezony [8]. Znalosti o\u00a0zastoupen\u00ed hol\u00e9 p\u016fdy v\u00a0erozn\u011b rizikov\u00fdch period\u00e1ch roku pak pom\u00e1haj\u00ed jednak zac\u00edlit protierozn\u00ed ochranu, ale rovn\u011b\u017e l\u00e9pe vytipovat lokality, kde je t\u0159eba po v\u00fdskytu p\u0159\u00edvalov\u00fdch sr\u00e1\u017eek monitoringem ov\u011b\u0159it, zda ke skute\u010dn\u00e9mu erozn\u00edmu po\u0161kozen\u00ed doch\u00e1z\u00ed. V\u00fdzkumn\u00fd \u00fastav meliorac\u00ed a\u00a0ochrany p\u016fdy inicioval dlouhodob\u00fd celost\u00e1tn\u00ed monitoring eroze zem\u011bd\u011blsk\u00e9 p\u016fdy, kter\u00fd je v\u00fdznamn\u00fdm verifika\u010dn\u00edm n\u00e1strojem pro v\u00fd\u0161e uveden\u00e9 hodnocen\u00ed metodou USLE, ale tak\u00e9 pro \u0159adu sr\u00e1\u017ekoodtokov\u00fdch model\u016f transportu splavenin do povrchov\u00fdch vod a\u00a0infrastruktury. Samotn\u00fd monitoring je vlastn\u00edm \u0161et\u0159en\u00edm i\u00a0na podn\u011bty od ve\u0159ejnosti prov\u00e1d\u011bn pracovn\u00edky St\u00e1tn\u00edho pozemkov\u00e9ho \u00fa\u0159adu, kter\u00fd datab\u00e1zi za\u0161ti\u0165uje, a\u00a0pro ve\u0159ejnost je dostupn\u00fd na\u00a0adrese https:\/\/me.vumop.cz\/.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-1.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"151\" class=\"alignnone size-full wp-image-6154 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-1.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-1.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-1-300x57.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-1-768x145.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/151;\" \/><\/a>\n<h6>Obr. 1. Panoramatick\u00fd UAV sn\u00edmek \u0159e\u0161en\u00e9 lokality v\u00a0okol\u00ed \u0158isut s\u00a0uk\u00e1zkou rozsahu hol\u00fdch p\u016fd (17.\u00a03.\u00a02016)<br \/>\nFig. 1. Panoramic UAV image of the area around \u0158isuty with a\u00a0demonstration of the extent of bare soil (17. 3. 2016)<\/h6>\n<p>Distan\u010dn\u00ed metody monitoringu (d\u00e1lkov\u00fd pr\u016fzkum Zem\u011b a\u00a0vyhodnocen\u00ed ortofotomap a\u00a0sn\u00edmk\u016f z\u00a0bezpilotn\u00edch prost\u0159edk\u016f) byly rozv\u00edjeny b\u011bhem projektu Ministerstva zem\u011bd\u011blstv\u00ed QJ1330118 Monitoring erozn\u00edho po\u0161kozen\u00ed p\u016fd a\u00a0projev\u016f eroze pomoc\u00ed metod DPZ \u0159e\u0161en\u00e9ho v\u00a0letech 2013\u20132016 a\u00a0jeho v\u00fdsledky byly publikov\u00e1ny v\u00a0certifikovan\u00e9 metodice [8]. S\u00a0c\u00edlem l\u00e9pe vyu\u017e\u00edt metody d\u00e1lkov\u00e9ho pr\u016fzkumu pro predikci lokalit, kde je vhodn\u00e9 prov\u00e9st operativn\u00ed pozemn\u00ed pr\u016fzkum, byl zah\u00e1jen n\u00e1vazn\u00fd projekt QK1720289 V\u00fdvoj automatizovan\u00e9ho n\u00e1stroje pro optimalizaci monitoringu eroze zem\u011bd\u011blsk\u00e9 p\u016fdy pomoc\u00ed distan\u010dn\u00edch metod. Propojen\u00ed hodnocen\u00ed erozn\u00edho rizika a\u00a0postup\u016f precizn\u00edho zem\u011bd\u011blstv\u00ed si pak klade za jeden z\u00a0c\u00edl\u016f projekt EIP Implementace nov\u00fdch a\u00a0inovovan\u00fdch technologi\u00ed precizn\u00edho zem\u011bd\u011blstv\u00ed do p\u011bstebn\u00edch syst\u00e9m\u016f, registra\u010dn\u00ed \u010d\u00edslo 16\/003\/1611a\/120\/000095. Ten je \u0159e\u0161en ve spolupr\u00e1ci se spole\u010dnost\u00ed\u00a0AGRA \u0158isuty, s. r. o., na jej\u00edch\u017e pozemc\u00edch byly rovn\u011b\u017e testov\u00e1ny prezentovan\u00e9 postupy.<\/p>\n<h2>Metodika<\/h2>\n<h3>Lokalita<\/h3>\n<p>Z\u00e1jmov\u00e9 pozemky se nach\u00e1zej\u00ed severov\u00fdchodn\u011b od Prahy, nedaleko okresn\u00edho m\u011bsta Slan\u00fd. Pozemky se rozkl\u00e1daj\u00ed na katastr\u00e1ln\u00edch \u00fazem\u00edch celkem 16 obc\u00ed, a\u00a0to Byse\u0148, Drnek, Hrade\u010dno, Jedom\u011blice, Ledce u\u00a0Kladna, Libovice u\u00a0Slan\u00e9ho, Lodenice, Lotou\u0161, Mal\u00edkovice, M\u0161ec, Pozde\u0148, P\u0159el\u00edc, \u0158isuty u\u00a0Slan\u00e9ho, Sme\u010dno, Studen\u011bves a\u00a0Svina\u0159ov u\u00a0Kladna. Jedn\u00e1 se celkem o\u00a0129 pozemk\u016f s\u00a0celkovou rozlohou 1 731\u2008ha. Vyu\u017eit\u00ed pozemk\u016f je p\u0159edev\u0161\u00edm jako standardn\u00ed orn\u00e1 p\u016fda, v\u00a0men\u0161\u00ed m\u00ed\u0159e travn\u00ed porost na orn\u00e9 p\u016fd\u011b \u010di trval\u00fd travn\u00ed porost (<em>obr. 1<\/em>).<\/p>\n<p>Morfologie oblasti m\u00e1 charakter ploch\u00e9 pahorkatiny s\u00a0v\u00fd\u0161kovou \u010dlenitost\u00ed 30 a\u017e 75 metr\u016f. Nadmo\u0159sk\u00e1 v\u00fd\u0161ka \u0159e\u0161en\u00fdch pozemk\u016f je v\u00a0rozmez\u00ed 280 a\u017e 430\u2008m\u00a0n.\u00a0m. Pr\u016fm\u011brn\u00e9 sklony na \u0159e\u0161en\u00fdch pozemc\u00edch se pohybuj\u00ed v\u00a0rozmez\u00ed 2,7\u20135,9\u00b0. Z\u00a0klimatick\u00e9ho hlediska je oblast m\u00edrn\u011b tepl\u00e1 a\u00a0such\u00e1 s\u00a0m\u00edrnou zimou. Pr\u016fm\u011brn\u00e1 ro\u010dn\u00ed teplota se pohybuje okolo 8\u2008\u00b0C. Ro\u010dn\u00ed sr\u00e1\u017ekov\u00fd \u00fahrn z\u00a0hlediska \u010cR je podpr\u016fm\u011brn\u00fd a\u00a0pohybuje se mezi 450 a\u017e 550\u2008mm.<\/p>\n<p>Farma AGRA \u0158isuty dlouhodob\u011b aplikuje m\u011blk\u00e9 zpracov\u00e1n\u00ed p\u016fdy a\u00a0\u0161etrn\u00e9 technologie, b\u011bhem monitoringu erozn\u00ed ohro\u017eenosti prov\u00e1d\u011bn\u00e9ho na pozemc\u00edch farmy proto nebylo zachyceno v\u00fdrazn\u00e9 erozn\u00ed po\u0161kozen\u00ed.<\/p>\n<h3>Vstupn\u00ed data<\/h3>\n<p>Pro stahov\u00e1n\u00ed a\u00a0z\u00e1kladn\u00ed zpracov\u00e1n\u00ed dru\u017eicov\u00fdch sc\u00e9n je mo\u017en\u00e9 v\u00a0sou\u010dasn\u00e9 dob\u011b vyu\u017e\u00edt \u0159adu internetov\u00fdch port\u00e1l\u016f. Pro data z\u00a0programu Landsat jsou to Earth Explorer [9], GloVis, LandsatLook, ESA Landsat 8 Portal (pouze pro Landsat\u00a08), Global Land Cover Facility [10] a\u00a0jin\u00e9. Zaj\u00edmav\u00fdm rozhran\u00edm je port\u00e1l Global Land Cover Facility, kde jsou ke sta\u017een\u00ed jak vybran\u00e9 sc\u00e9ny z\u00a0n\u011bkter\u00fdch dru\u017eic (Landsat, Terra, Ikonos), tak odvozen\u00e9 produkty (nap\u0159. krajinn\u00fd pokryv, vegeta\u010dn\u00ed index, maska vodn\u00edch ploch nebo albedo). Pro p\u0159\u00edstup k\u00a0dat\u016fm z\u00a0dru\u017eic Sentinel v\u0161em u\u017eivatel\u016fm slou\u017e\u00ed port\u00e1l ESA Sentinel Scientific Data Hub, pro sta\u017een\u00ed sc\u00e9n sta\u010d\u00ed jednoduch\u00e1 registrace. P\u0159\u00edm\u00e9 anal\u00fdzy nad daty lze prov\u00e1d\u011bt efektivn\u011b v\u00a0komer\u010dn\u00edm prost\u0159ed\u00ed nazvan\u00e9m jednodu\u0161e Sentinel Hub, provozovan\u00e9m firmou Sinergise [11]. Zaj\u00edmav\u00fdm zdrojem dru\u017eicov\u00fdch sc\u00e9n obou syst\u00e9m\u016f pak m\u016f\u017ee b\u00fdt server LandViewer [12], provozovan\u00fd firmou EOS. Ten byl vyu\u017eit i\u00a0pro zaji\u0161t\u011bn\u00ed dat na lokalit\u011b \u0158isuty.<\/p>\n<p>Periodicita sc\u00e9n z\u00a0dru\u017eice Landsat 8 je 16\u00a0dn\u00ed. Za vegeta\u010dn\u00ed sezonu osmi m\u011bs\u00edc\u016f (obdob\u00ed b\u0159ezen\u2013\u0159\u00edjen) jich tedy teoreticky m\u016f\u017ee b\u00fdt k\u00a0dispozici a\u017e 15. Periodicita dru\u017eice Sentinel 2\u2008A je pro \u0159e\u0161en\u00e9 \u00fazem\u00ed m\u00e9n\u011b ne\u017e 7\u00a0dn\u00ed, nicm\u00e9n\u011b data za\u010dala b\u00fdt po\u0159izov\u00e1na od \u010dervence 2015. Spole\u010dn\u011b s\u00a0dru\u017eic\u00ed Sentinel 2\u2008B je periodicita dat pro \u0159e\u0161en\u00e9 \u00fazem\u00ed v\u00a0rozmez\u00ed 3\u20134\u00a0dny, nicm\u00e9n\u011b tato data za\u010dala b\u00fdt po\u0159izov\u00e1na v\u00a0b\u0159eznu 2017. V\u00a0sou\u010dasnosti proto \u010dist\u011b teoreticky m\u016f\u017ee b\u00fdt k\u00a0dispozici pro obdob\u00ed osmi m\u011bs\u00edc\u016f b\u0159ezen\u2013\u0159\u00edjen a\u017e 80 r\u016fzn\u00fdch satelitn\u00edch sc\u00e9n z\u00a0uveden\u00fdch syst\u00e9m\u016f. Nicm\u00e9n\u011b dostupnost dat zna\u010dn\u011b limituje obla\u010dnost nad hledan\u00fdm \u00fazem\u00edm a\u00a0re\u00e1ln\u011b dostupn\u00e9 po\u010dty sc\u00e9n jsou podstatn\u011b ni\u017e\u0161\u00ed. Data dru\u017eic Sentinel 2 jsou poskytov\u00e1na v\u00a0r\u016fzn\u00fdch \u00farovn\u00edch p\u0159edzpracov\u00e1n\u00ed, surov\u00e1 data z\u00a0v\u00fd\u0161e uvedenou frekvenc\u00ed nejsou p\u0159\u00edmo prakticky vyu\u017eiteln\u00e1. Pro praktick\u00e9 vyu\u017eit\u00ed je t\u0159eba \u010derpat ze sc\u00e9n p\u0159eveden\u00fdch do produktu \u00farovn\u011b L1C, kter\u00e9 jsou o\u0161et\u0159eny atmosf\u00e9rickou korekc\u00ed a\u00a0ortorektifikov\u00e1ny [2]. Dostupn\u00fd po\u010det skute\u010dn\u011b vyu\u017eiteln\u00fdch sc\u00e9n je tak proti teoretick\u00e9mu po\u010dtu vypo\u010dten\u00e9mu z\u00a0periody obletu ji\u017e zna\u010dn\u011b omezen.<\/p>\n<p>V\u00a0datab\u00e1zi satelitn\u00edch sc\u00e9n na serveru LandViewer byla vybr\u00e1na z\u00e1jmov\u00e1 lokalita a\u00a0pro ni byly vybr\u00e1ny sc\u00e9ny po\u0159\u00edzen\u00e9 dru\u017eicemi Landsat 8, Sentinel 2\u2008A a\u00a0Sentinel 2\u2008B. P\u0159i podm\u00ednce obla\u010dnosti ni\u017e\u0161\u00ed ne\u017e 20\u00a0% bylo pro vegeta\u010dn\u00ed sezonu (obdob\u00ed b\u0159ezen\u2013\u0159\u00edjen) roku 2015 nalezeno 17 sc\u00e9n, pro vegeta\u010dn\u00ed sezonu roku 2016 bylo nalezeno 23 sc\u00e9n a\u00a0pro vegeta\u010dn\u00ed sezonu roku 2017 potom 18 sc\u00e9n (<em>obr. 2<\/em>). Z\u00a0t\u011bchto soubor\u016f pak byly vyb\u00edr\u00e1ny sc\u00e9ny, na kter\u00fdch je cel\u00e1 z\u00e1jmov\u00e1 oblast nezast\u00edn\u011bna obla\u010dnost\u00ed. Po\u010det vhodn\u00fdch sc\u00e9n tak byl d\u00e1le redukov\u00e1n zhruba na \u010dtvrtinu.<\/p>\n<p>&nbsp;<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-2.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"299\" class=\"alignnone size-full wp-image-6156 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-2.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-2.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-2-300x112.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-2-768x287.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/299;\" \/><\/a>\n<h6>Obr. 2. Dostupn\u00e9 bezobla\u010dn\u00e9 dru\u017eicov\u00e9 sc\u00e9ny z\u00e1jmov\u00e9ho \u00fazem\u00ed v\u00a0letech 2015\u20132017<br \/>\nFig. 2. Available cloudless satellite scenes of the target area for the years 2015\u20132017<\/h6>\n<p>Celkem bylo analyzov\u00e1no 16 sc\u00e9n, pro ka\u017ed\u00fd rok jich bylo nejm\u00e9n\u011b p\u011bt (<em>tabulka 1<\/em>). Data po\u0159\u00edzen\u00ed vybran\u00fdch sc\u00e9n byla volena tak, aby co nejv\u00edce postihovala vegeta\u010dn\u00ed obdob\u00ed a\u00a0tu \u010d\u00e1st roku, kdy je nejvy\u0161\u0161\u00ed riziko v\u00fdskytu sr\u00e1\u017ekov\u00fdch ud\u00e1lost\u00ed zp\u016fsobuj\u00edc\u00edch erozn\u00ed po\u0161kozen\u00ed.<\/p>\n<p>Pou\u017eity byly sc\u00e9ny z\u00a0dru\u017eice Landsat 8\u2008s\u00a0prostorov\u00fdm rozli\u0161en\u00edm 30\u2008m. Pouze dru\u017eicov\u00e1 sc\u00e9na ze dne 27. 8. 2016 je po\u0159\u00edzena dru\u017eic\u00ed Sentinel 2\u2008s\u00a0prostorov\u00fdm rozli\u0161en\u00edm 10\u2008m. V\u017edy byly sta\u017eeny rastry kompozice RGB, NI a\u00a0NDVI, tedy viditeln\u00e1 a\u00a0bl\u00edzk\u00e1 infra\u010derven\u00e1 p\u00e1sma spektra.<\/p>\n<p>Pro hodnocen\u00e9 pozemky byla d\u00e1le firmou AGRA \u0158isuty poskytnuta re\u00e1ln\u00e1 data o\u00a0plodin\u00e1ch, datech set\u00ed a\u00a0sklizn\u00ed a\u00a0v\u00fdnosech v\u00a0letech 2015, 2016 a\u00a02017. Data byla z\u00a0hlediska precizn\u00edho zem\u011bd\u011blstv\u00ed dopln\u011bna o\u00a0izolinie pr\u016fm\u011brn\u00fdch normalizovan\u00fdch v\u00fdnos\u016f na jednotliv\u00fdch pozemc\u00edch. V\u00fdsledn\u00fd normalizovan\u00fd v\u00fdnos vyjad\u0159uje, o\u00a0kolik procent byl v\u00a0dan\u00e9m bod\u011b v\u00fdnos vy\u0161\u0161\u00ed nebo ni\u017e\u0161\u00ed ne\u017e pr\u016fm\u011br cel\u00e9ho pozemku v\u00a0dan\u00e9m roce [1]. Tento relativn\u00ed v\u00fdnosov\u00fd potenci\u00e1l (\u010di produk\u010dn\u00ed z\u00f3ny) vych\u00e1z\u00ed z\u00a0hodnocen\u00ed variability porostu z\u00a0dru\u017eicov\u00fdch multispektr\u00e1ln\u00edch sn\u00edmk\u016f za posledn\u00edch 8\u00a0let. Procentu\u00e1ln\u00ed hodnota je stanovena pro ka\u017ed\u00fd pozemek zvl\u00e1\u0161\u0165 a\u00a0ukazuje na slab\u00e1 \u010di siln\u00e1 m\u00edsta na pozemc\u00edch. Nelze v\u0161ak porovn\u00e1vat pozemky mezi sebou, u\u017e jen z\u00a0principu rozd\u00edln\u00fdch plodin. Pro \u0158isuty byly z\u00f3ny vypo\u010dteny s\u00a0rozli\u0161en\u00edm 5\u2008m. Pro \u00fazem\u00ed cel\u00e9 \u010cesk\u00e9 republiky jsou v\u00a0hrub\u00e9 podob\u011b produk\u010dn\u00ed z\u00f3ny dostupn\u00e9 na adrese http:\/\/foodie.lesprojekt.cz.<\/p>\n<h5>Tabulka 1. Seznam analyzovan\u00fdch sc\u00e9n, ve kter\u00fdch se nevyskytovala obla\u010dnost nad pozemky AGRA \u0158isuty<br \/>\nTable 1. List of analyzed scenes with detected no cloud cover over target area<\/h5>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-tabulka-1.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"105\" class=\"alignnone size-full wp-image-6170 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-tabulka-1.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-tabulka-1.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-tabulka-1-300x39.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-tabulka-1-768x101.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/105;\" \/><\/a>\n<p>Pro hodnocen\u00ed erozn\u00ed ohro\u017eenosti byly potom vyu\u017eity n\u00e1sleduj\u00edc\u00ed \u00fadaje. V\u00fd\u0161kopis, kter\u00fd vstupuje do pou\u017eit\u00e9ho modelu Atlas EROZE jako mra\u010dno bod\u016f z\u00a0digit\u00e1ln\u00edho modelu reli\u00e9fu 5. generace [13]. Faktor erozn\u00edho \u00fa\u010dinku de\u0161t\u011b, kter\u00fd je uva\u017eov\u00e1n pr\u016fm\u011brnou dlouhodobou ro\u010dn\u00ed hodnotou 40\u2008MJ.ha<sup>-1<\/sup>.cm.h<sup>-1<\/sup> [14]. Faktor erodovatelnosti p\u016fdy, odvozen\u00fd z\u00a0voln\u011b dostupn\u00fdch vektorov\u00fdch map bonitovan\u00fdch p\u016fdn\u011b ekologick\u00fdch jednotek [15]. Faktor ochrann\u00e9ho \u00fa\u010dinku vegetace, kter\u00fd je odvozen z\u00a0v\u00fd\u0161e uveden\u00fdch \u00fadaj\u016f o\u00a0osevn\u00edch postupech a\u00a0term\u00ednech agrotechnick\u00fdch operac\u00ed. Technick\u00e1 protierozn\u00ed opat\u0159en\u00ed nejsou na pozemc\u00edch farmy AGRA \u0158isuty aplikov\u00e1na.<\/p>\n<h3>Identifikace p\u016fdy nepokryt\u00e9 vegetac\u00ed<\/h3>\n<p>Nepokryt\u00e9 p\u016fdy byly na sc\u00e9n\u00e1ch identifikov\u00e1ny na tr\u00e9novac\u00edch mno\u017ein\u00e1ch, tedy vybran\u00fdch p\u016fdn\u00edch bloc\u00edch. Na jarn\u00edch sc\u00e9n\u00e1ch to byly jednak pozemky \u010derstv\u011b po zaset\u00ed, evidovan\u00e9 podle term\u00ednu set\u00ed jednotliv\u00fdch plodin, d\u00e1le pozemky prokazateln\u011b bez vegetace p\u0159i RGB zobrazen\u00ed v\u00a0p\u0159irozen\u00fdch barv\u00e1ch. Na ostatn\u00edch sc\u00e9n\u00e1ch pak pozemky s\u00a0analogick\u00fdm p\u0159\u00edznakem v\u00a0RGB zobrazen\u00ed a\u00a0rovn\u011b\u017e s\u00a0hodnotami indexu NDVI ukazuj\u00edc\u00edmi na neexistenci vegetace na dan\u00fdch pozemc\u00edch. Po vytvo\u0159en\u00ed tr\u00e9novac\u00edch mno\u017ein byly n\u00e1sledn\u011b hol\u00e9 p\u016fdy na ka\u017ed\u00e9 sc\u00e9n\u011b vyhodnoceny na v\u0161ech LPIS bloc\u00edch pomoc\u00ed \u0159\u00edzen\u00e9 klasifikace klasifik\u00e1torem Maximum Likelihood v\u00a0prost\u0159ed\u00ed ArcGIS. Cel\u00e1 anal\u00fdza prob\u00edhala pouze na zem\u011bd\u011blsk\u00e9 p\u016fd\u011b, ostatn\u00ed kategorie vyu\u017eit\u00ed byly ponech\u00e1ny jako nehodnocen\u00e1 data. Dal\u0161\u00edm krokem bylo ur\u010den\u00ed procenta v\u00fdskytu hol\u00e9 p\u016fdy v\u00a0ka\u017ed\u00e9m obdob\u00ed na ka\u017ed\u00e9m pozemku n\u00e1stroji prostorov\u00e9 statistiky. Data byla z\u00a0map p\u0159evedena do atribut\u016f datab\u00e1ze pozemk\u016f a\u00a0do grafick\u00e9ho vyj\u00e1d\u0159en\u00ed. Data o\u00a0hol\u00e9 p\u016fd\u011b dostupn\u00e1 z\u00a0dru\u017eicov\u00fdch sc\u00e9n byla dopln\u011bna o\u00a0data zn\u00e1m\u00e1 z\u00a0term\u00edn\u016f agrotechnick\u00fdch prac\u00ed (term\u00edny set\u00ed), ve kter\u00fdch jsou pozemky ozna\u010deny jako zcela hol\u00e9. N\u00e1sledn\u011b byly hol\u00e9 \u010d\u00e1sti pozemk\u016f ve vegeta\u010dn\u00edm obdob\u00ed konfrontov\u00e1ny s\u00a0rizikem v\u00fdskytu erozn\u011b \u00fa\u010dinn\u00fdch sr\u00e1\u017eek a\u00a0s\u00a0prostorov\u011b distribuovanou vrstvou potenci\u00e1ln\u00ed erozn\u00ed ohro\u017eenosti.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-3.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"761\" class=\"alignnone size-full wp-image-6158 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-3.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-3.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-3-300x285.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-3-768x731.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/761;\" \/><\/a>\n<h6>Obr. 3. Uk\u00e1zka porovn\u00e1n\u00ed zm\u011bny prostorov\u00e9 distribuce hol\u00e9 p\u016fdy na pozemc\u00edch v\u00a0letech 2015\u20132017 se zohledn\u011bn\u00edm rizika v\u00fdskytu erozn\u00edch sr\u00e1\u017eek v\u00a0ka\u017ed\u00e9m roce podle <em>tabulky 2<br \/>\n<\/em>Fig. 3. Comparison of the changes of spatial distribution of bare soil in the years 2015\u20132017, taking into account the risk of erosion of rainfall according to the <em>table 2<\/em><\/h6>\n<p>Prostorov\u011b bylo v\u00a0GIS mapovou algebrou vypo\u010dteno riziko v\u00fdskytu hol\u00fdch p\u016fd b\u011bhem vegeta\u010dn\u00ed sezony s\u00a0ohledem na riziko v\u00fdskytu erozn\u011b \u00fa\u010dinn\u00fdch sr\u00e1\u017eek. V\u00fdpo\u010det vych\u00e1zel z\u00a0dlouhodob\u00e9ho pr\u016fm\u011brn\u00e9ho erozn\u00edho \u00fa\u010dinku sr\u00e1\u017eek (R-faktoru) v\u00a0jednotliv\u00fdch m\u011bs\u00edc\u00edch v\u00a0procentech za obdob\u00ed duben\u2013z\u00e1\u0159\u00ed [14]. Toto obdob\u00ed p\u0159edstavuje 100\u00a0% celkov\u00e9ho erozn\u00edho \u00fa\u010dinku sr\u00e1\u017eek. Distribuce erozn\u011b \u00fa\u010dinn\u00fdch sr\u00e1\u017eek b\u011bhem roku pro obdob\u00ed posledn\u00ed dek\u00e1dy byla nov\u011b ur\u010dena \u010cHM\u00da [16]. Princip v\u00fdpo\u010dtu byl n\u00e1sleduj\u00edc\u00ed.<\/p>\n<p>Pro term\u00edn ka\u017ed\u00e9 analyzovan\u00e9 dru\u017eicov\u00e9 sc\u00e9ny je v\u00e1\u017een\u00fdm pr\u016fm\u011brem ur\u010deno procento erozn\u00edho \u00fa\u010dinku sr\u00e1\u017eek reprezentovan\u00e9ho obdob\u00ed. Procenta z\u00a0tabulky (<em>tabulka 2<\/em>) jsou takto line\u00e1rn\u00ed interpolac\u00ed rozd\u011blena mezi data, ve kter\u00fdch byl ur\u010den v\u00fdskyt hol\u00fdch p\u016fd v\u00a0ka\u017ed\u00e9 sezon\u011b. Pixel\u016fm hol\u00e9 p\u016fdy z\u00a0dan\u00e9 sc\u00e9ny je p\u0159i\u0159azena tato hodnota procenta R-faktoru. Hol\u00e1 p\u016fda identifikovan\u00e1 na dan\u00e9 dru\u017eicov\u00e9 sc\u00e9n\u011b m\u00e1 tedy v\u00e1hu odpov\u00eddaj\u00edc\u00ed obdob\u00ed reprezentovan\u00e9mu datem po\u0159\u00edzen\u00ed sc\u00e9ny. Tato procenta z\u00edskan\u00e1 ze v\u0161ech analyzovan\u00fdch sc\u00e9n v\u00a0dan\u00e9m bod\u011b pozemku byla v\u017edy pro danou sezonu se\u010dtena. Pokud by se tedy na dan\u00e9 \u010d\u00e1sti pozemku vyskytovala hol\u00e1 p\u016fda po cel\u00e9 sledovan\u00e9 obdob\u00ed konkr\u00e9tn\u00edho roku, z\u00edskala by ve v\u00fdsledn\u00e9 map\u011b hodnotu pr\u00e1v\u011b 100\u00a0%, tedy by byla uva\u017eov\u00e1na jako zcela nechr\u00e1n\u011bn\u00e1 proti erozi v\u00a0dan\u00e9m roce.<\/p>\n<p>N\u00e1sledn\u011b bylo je\u0161t\u011b vypo\u010dteno pr\u016fm\u011brn\u00e9 dlouhodob\u00e9 riziko v\u00fdskytu hol\u00e9 p\u016fdy jako pr\u016fm\u011br ze sledovan\u00fdch let.<\/p>\n<h2>V\u00fdpo\u010det erozn\u00ed ohro\u017eenosti<\/h2>\n<p>Erozn\u00ed ohro\u017eenost byla po\u010d\u00edt\u00e1na v\u00a0prost\u0159ed\u00ed modelu Atlas EROZE. Atlas pracuje s\u00a0digit\u00e1ln\u00edm modelem ter\u00e9nu jako s\u00a0prostorovou plochou, kter\u00e1 kop\u00edruje zam\u011b\u0159en\u00fd nebo projektovan\u00fd ter\u00e9n. Vznik\u00e1 na z\u00e1klad\u011b 3D bod\u016f, \u010dar a\u00a0ploch, kter\u00fdmi proch\u00e1z\u00ed. V\u00fdpo\u010det mezi zadan\u00fdmi body je upraven pro modelov\u00e1n\u00ed hladk\u00e9ho ter\u00e9nu. Form\u00e1t vstupn\u00edch dat, v\u00fdstupn\u00edch model\u016f a\u00a0v\u00fdstupn\u00edch protokol\u016f je v\u00a0souladu s\u00a0platn\u00fdmi metodikami pou\u017e\u00edvan\u00fdmi p\u0159i pozemkov\u00fdch \u00faprav\u00e1ch v\u00a0\u010cesk\u00e9 republice. Metodou v\u00fdpo\u010dtu je proto plo\u0161n\u011b distribuovan\u00e1 (2D) verze Univerz\u00e1ln\u00ed rovnice ztr\u00e1ty p\u016fdy (1) (USLE) ve tvaru:<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-vzorecek-1.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"111\" class=\"alignnone size-full wp-image-6174 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-vzorecek-1.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-vzorecek-1.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-vzorecek-1-300x42.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-vzorecek-1-768x107.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/111;\" \/><\/a>\n<table class=\"no-border\">\n<tbody>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73px; height: 24px;\">kde<\/td>\n<td style=\"width: 71px; height: 24px;\">G<\/td>\n<td style=\"width: 59px; height: 24px;\">je<\/td>\n<td style=\"width: 1148px; height: 24px;\">pr\u016fm\u011brn\u00e1 dlouhodob\u00e1 ztr\u00e1ta p\u016fdy [t.ha<sup>-1<\/sup>.rok<sup>-1<\/sup>],<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73px; height: 24px;\"><\/td>\n<td style=\"width: 71px; height: 24px;\">R<\/td>\n<td style=\"width: 59px; height: 24px;\"><\/td>\n<td style=\"width: 1148px; height: 24px;\">faktor erozn\u00ed \u00fa\u010dinnosti de\u0161t\u011b [MJ.ha<sup>-1<\/sup>.cm.h<sup>-1<\/sup>],<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73px; height: 24px;\"><\/td>\n<td style=\"width: 71px; height: 24px;\">K<\/td>\n<td style=\"width: 59px; height: 24px;\"><\/td>\n<td style=\"width: 1148px; height: 24px;\">faktor erodovatelnosti p\u016fdy [t.h.MJ<sup>-1<\/sup>.cm<sup>-1<\/sup>],<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73px; height: 24px;\"><\/td>\n<td style=\"width: 71px; height: 24px;\">L<\/td>\n<td style=\"width: 59px; height: 24px;\"><\/td>\n<td style=\"width: 1148px; height: 24px;\">faktor d\u00e9lky svahu (-),<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73px; height: 24px;\"><\/td>\n<td style=\"width: 71px; height: 24px;\">S<\/td>\n<td style=\"width: 59px; height: 24px;\"><\/td>\n<td style=\"width: 1148px; height: 24px;\">faktor sklonu svahu (-),<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73px; height: 24px;\"><\/td>\n<td style=\"width: 71px; height: 24px;\">C<\/td>\n<td style=\"width: 59px; height: 24px;\"><\/td>\n<td style=\"width: 1148px; height: 24px;\">faktor ochrann\u00e9ho vlivu vegeta\u010dn\u00edho krytu (-),<\/td>\n<\/tr>\n<tr style=\"height: 24px;\">\n<td style=\"width: 73px; height: 24px;\"><\/td>\n<td style=\"width: 71px; height: 24px;\">P<\/td>\n<td style=\"width: 59px; height: 24px;\"><\/td>\n<td style=\"width: 1148px; height: 24px;\">faktor \u00fa\u010dinnosti protierozn\u00edch opat\u0159en\u00ed (neuva\u017eov\u00e1n).<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>&nbsp;<\/p>\n<p>V\u00fdsledn\u00fd vztah pro LS faktor je d\u00e1n kombinac\u00ed rovnic podle Mit\u00e1\u0161ov\u00e9 [17], Desmeta a\u00a0Goverse [18] a\u00a0Nearinga [19]. Plocha d\u00edl\u010d\u00edch povod\u00ed je po\u010d\u00edt\u00e1na pomoc\u00ed algoritmu identifikace odtokov\u00fdch lini\u00ed p\u0159\u00edmo na modelech typu TIN. V\u00fdstupem je rastr LS faktoru, jeho\u017e rozli\u0161en\u00ed je ur\u010deno u\u017eivatelem v\u00a0nastaven\u00ed programu. Odtokov\u00e9 linie jsou vytv\u00e1\u0159eny spou\u0161t\u011bn\u00edm \u201ekapek\u201c na TIN model v\u00a0hustot\u011b, kter\u00e1 je d\u00e1na nastaven\u00fdm rozli\u0161en\u00edm. V\u00a0tomto v\u00fdpo\u010dtu bylo zvoleno rozli\u0161en\u00ed 5\u2008m. Ostatn\u00ed faktory USLE p\u0159ev\u00e1d\u00ed model Atlas EROZE na z\u00e1klad\u011b u\u017eivatelsk\u00fdch vstup\u016f na plo\u0161n\u011b distribuovan\u00e9 rastrov\u00e9 modely s\u00a0rozli\u0161en\u00edm v\u00fdstupn\u00edho LS faktoru.<\/p>\n<p>Faktor ochrann\u00e9ho vlivu vegetace byl uva\u017eov\u00e1n ve dvou variant\u00e1ch. Jednak jako skute\u010dn\u00e1 hodnota faktoru C na ka\u017ed\u00e9m pozemku, vych\u00e1zej\u00edc\u00ed z\u00a0re\u00e1ln\u00fdch osevn\u00edch postup\u016f za obdob\u00ed 2015\u20132017 standardn\u00ed metodou [14], jednak jako reprezentativn\u00ed hodnota identick\u00e1 pro v\u0161echny pozemky orn\u00e9 p\u016fdy, za \u00fa\u010delem v\u00fdpo\u010dtu relativn\u00ed erozn\u00ed ohro\u017eenosti na v\u0161ech pozemc\u00edch, nez\u00e1visl\u00e9 na konkr\u00e9tn\u00ed skladb\u011b plodin za \u0159e\u0161en\u00e9 t\u0159\u00edlet\u00e9 obdob\u00ed.<\/p>\n<h2>V\u00fdsledky<\/h2>\n<h3>V\u00fdskyt p\u016fdy nezakryt\u00e9 vegetac\u00ed<\/h3>\n<p>Mapy v\u00fdskytu hol\u00fdch p\u016fd b\u011bhem vegeta\u010dn\u00ed sezony s\u00a0ohledem na riziko v\u00fdskytu erozn\u011b \u00fa\u010dinn\u00fdch sr\u00e1\u017eek byly vytvo\u0159eny v\u00a0rozli\u0161en\u00ed 30\u2008m, odpov\u00eddaj\u00edc\u00edmu p\u016fvodn\u00edm dru\u017eicov\u00fdm sc\u00e9n\u00e1m. Mapy ukazuj\u00ed na rizikov\u00e9 partie pozemk\u016f v\u00a0ka\u017ed\u00e9 sledovan\u00e9 sezon\u011b od dubna do kv\u011btna v\u00a0letech 2015\u20132017 (<em>obr. 3<\/em>).<\/p>\n<p>Z\u00a0prezentovan\u00fdch map je z\u0159ejm\u00e9, \u017ee v\u00a0r\u00e1mci zkouman\u00e9ho t\u0159\u00edlet\u00e9ho obdob\u00ed je variabilita hol\u00fdch p\u016fd v\u00a0letn\u00edm obdob\u00ed na pozemc\u00edch velmi vysok\u00e1, v\u00a0z\u00e1vislosti na osevn\u00edch postupech. Zejm\u00e9na z\u00e1vis\u00ed na tom, kter\u00e9 pozemky jsou vybr\u00e1ny pro set\u00ed ozim\u00e9 \u0159epky, je\u017e prob\u00edh\u00e1 je\u0161t\u011b v\u00a0dob\u011b vysok\u00e9ho rizika erozn\u00edch sr\u00e1\u017eek, v\u00a0pr\u016fb\u011bhu srpna, v\u00a0z\u00e1vislosti na klimatu dan\u00e9ho roku. Rovn\u011b\u017e celkov\u00e1 d\u00e9lka obdob\u00ed s\u00a0holou p\u016fdou na dan\u00e9m pozemku se obvykle v\u00a0ka\u017ed\u00e9m roce li\u0161\u00ed, v\u00a0letech 2015 a\u00a02016 byla na \u0159ad\u011b pozemk\u016f mnohem del\u0161\u00ed ne\u017e v\u00a0roce 2017. Na mnoha pozemc\u00edch se v\u00a0roce 2015 (kdy byla situace nejhor\u0161\u00ed) vyskytovalo vysok\u00e9 procento hol\u00e9 p\u016fdy rovn\u011b\u017e vlivem extr\u00e9mn\u00edho sucha, a\u00a0tedy omezen\u00e9ho r\u016fstu p\u011bstovan\u00fdch plodin. Kumulativn\u00ed mapa v\u00fdskytu hol\u00fdch p\u016fd v\u00a0l\u00e9t\u011b za cel\u00e9 t\u0159\u00edlet\u00e9 obdob\u00ed vlivem v\u00fd\u0161e uveden\u00e9 \u010dasov\u00e9 a\u00a0prostorov\u00e9 variability ji\u017e proto neukazuje na tak v\u00fdznamn\u00e9 rozd\u00edly a\u00a0hodnoty dosahuj\u00ed maxim\u00e1ln\u011b 50\u00a0% (<em>obr. 4<\/em>).<\/p>\n<p>Nejrizikov\u011bj\u0161\u00ed pozemky (severn\u011b od Studen\u011bvsi, okol\u00ed Pozdeni) tedy byly podle anal\u00fdzy dru\u017eicov\u00fdch dat vystaveny p\u016fsoben\u00ed a\u017e 50\u00a0% erozn\u011b \u00fa\u010dinn\u00fdch sr\u00e1\u017eek za cel\u00e9 t\u0159\u00edlet\u00e9 obdob\u00ed, ani\u017e by byly jakkoli chr\u00e1n\u011bny vegetac\u00ed. V\u00a0souhrnu byly pozemky AGRA \u0158isuty za obdob\u00ed 2015\u20132017 vystaven\u00e9 pr\u016fm\u011brn\u011b 20\u00a0% erozn\u00edho \u00fa\u010dinku sr\u00e1\u017eek, ani\u017e by byly chr\u00e1n\u011bny vegetac\u00ed. V\u00a0roce 2015 to bylo 35\u00a0%, v\u00a0roce 2016 pak 21\u00a0% a\u00a0v\u00a0roce 2017 pouze 6\u00a0%. Z\u00a0tohoto trendu je z\u0159ejm\u00e9, \u017ee bez ohledu na b\u011b\u017en\u00e9 postupy v\u00fdpo\u010dtu faktoru ochrann\u00e9ho \u00fa\u010dinku vegetace (C\u00a0\u2013 faktor) lze na z\u00e1klad\u011b anal\u00fdzy dru\u017eicov\u00fdch sc\u00e9n ur\u010dit podstatn\u011b vy\u0161\u0161\u00ed riziko erozn\u00edho ohro\u017een\u00ed \u0159ady pozemk\u016f v\u00a0such\u00e9m roce 2015 ne\u017e v\u00a0roce 2017. P\u0159itom AGRA \u0158isuty nep\u011bstuje \u0161iroko\u0159\u00e1dkov\u00e9 plodiny s\u00a0pozdn\u00edm vegeta\u010dn\u00edm n\u00e1stupem (kuku\u0159ice, brambory). P\u0159i jejich zahrnut\u00ed do osevn\u00edch postup\u016f by hodnoty rizikov\u00e9ho v\u00fdskytu hol\u00fdch p\u016fd byly je\u0161t\u011b vy\u0161\u0161\u00ed.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-4.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"867\" class=\"alignnone size-full wp-image-6160 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-4.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-4.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-4-277x300.jpg 277w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-4-768x832.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/867;\" \/><\/a>\n<h6>Obr. 4. Kombinovan\u00e1 mapa v\u00fdskytu hol\u00fdch p\u016fd v\u00a0rizikov\u00e9m obdob\u00ed za roky 2015\u20132017<br \/>\nFig. 4. A\u00a0combined map of the occurrence of the bare soil at risk period for the years 2015\u20132017<\/h6>\n<h3>Pr\u016fb\u011bh zastoupen\u00ed p\u016fdy bez vegetace<\/h3>\n<p>Pr\u016fb\u011bhy procentn\u00edho rozsahu hol\u00e9 p\u016fdy byly sledov\u00e1ny individu\u00e1ln\u011b pro ka\u017ed\u00fd jednotliv\u00fd pozemek a\u00a0nejprve byly sestaveny souhrnn\u00e9 grafy jednotliv\u00fdch plodin se zachov\u00e1n\u00edm informace o\u00a0konkr\u00e9tn\u00edch pozemc\u00edch. Zde je uveden p\u0159\u00edklad pro je\u010dmen jarn\u00ed v\u00a0sezon\u011b 2015 (<em>obr. 5<\/em>) s\u00a0vyzna\u010den\u00edm z\u00e1kladn\u00edch term\u00edn\u016f zm\u011bn.<\/p>\n<p>Z\u00a0obr\u00e1zku je jasn\u011b patrn\u00e1 v\u00fdrazn\u00e1 variabilita pr\u016fb\u011bhu r\u016fstu a\u00a0nerovnom\u011brnosti porost\u016f v\u00a0dan\u00e9m such\u00e9m roce. I\u00a0v\u00a0obdob\u00ed maxim\u00e1ln\u00edho vzr\u016fstu v\u00a0pr\u016fb\u011bhu \u010dervna a\u00a0\u010dervence se na n\u011bkter\u00fdch pozemc\u00edch vyskytla hol\u00e1 p\u016fda. V\u00a0z\u00e1vislosti na term\u00ednu dal\u0161\u00edho set\u00ed jsou pak pozemky zcela hol\u00e9 v\u00a0obdob\u00ed srpna, pokud n\u00e1sleduje oset\u00ed \u0159epkou ozimou, nebo a\u017e koncem \u0159\u00edjna, pokud je na nich ponech\u00e1no strni\u0161t\u011b a\u00a0n\u00e1sledn\u011b je zde seto triticale ozim\u00e9.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-5.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"507\" class=\"alignnone size-full wp-image-6162 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-5.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-5.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-5-300x190.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-5-768x487.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/507;\" \/><\/a>\n<h6>Obr. 5. Variabilita pr\u016fb\u011bhu zastoupen\u00ed hol\u00e9 p\u016fdy na pozemc\u00edch je\u010dmene jarn\u00edho v\u00a0roce 2015<br \/>\nFig. 5. The variability of the bare soil extent on the land of spring barley in 2015<\/h6>\n<p>Agregac\u00ed v\u00fdsledk\u016f zastoupen\u00ed p\u016fdy bez vegetace pro jednotliv\u00e9 plodiny byl z\u00edsk\u00e1n pr\u016fb\u011bh zastoupen\u00ed hol\u00e9 p\u016fdy pro sumu v\u0161ech pozemk\u016f (<em>obr. 6\u20138<\/em>). Tyto grafy op\u011bt ukazuj\u00ed p\u0159edpokl\u00e1dan\u00fd pokles zastoupen\u00ed hol\u00e9 p\u016fdy uprost\u0159ed vegeta\u010dn\u00ed sezony. Pro porovn\u00e1n\u00ed jsou v\u00a0grafech vyzna\u010deny rovn\u011b\u017e procentn\u00ed v\u00fdznamy jednotliv\u00fdch m\u011bs\u00edc\u016f z\u00a0hlediska dlouhodob\u00e9ho erozn\u00edho \u00fa\u010dinku sr\u00e1\u017eek (<em>tabulka 2<\/em>). Barvy pro plodiny jsou zachov\u00e1ny pro v\u0161echny t\u0159i sledovan\u00e9 roky, plodiny (p\u00e1sy grafu) jsou nicm\u00e9n\u011b se\u0159azeny podle rozsahu hol\u00e9 p\u016fdy na konci sledovan\u00e9ho obdob\u00ed. Z\u00a0pr\u016fb\u011bh\u016f je jasn\u011b viditeln\u00e9, jak se li\u0161\u00ed jednotliv\u00e9 plodiny a\u00a0jednotliv\u00e9 roky. V\u00a0souladu s\u00a0mapov\u00fdmi v\u00fdstupy prezentovan\u00fdmi v\u00fd\u0161e plat\u00ed, \u017ee nejvy\u0161\u0161\u00ed rozsah hol\u00e9 p\u016fdy b\u011bhem kritick\u00e9ho obdob\u00ed p\u0159\u00edvalov\u00fdch sr\u00e1\u017eek byl v\u00a0roce 2015. V\u00a0tomto roce dosahovala v\u00fdm\u011bra hol\u00e9 p\u016fdy b\u011bhem \u010dervence a\u00a0srpna a\u017e 60 a\u00a070\u00a0% celkov\u00e9 plochy v\u0161ech pozemk\u016f (to odpov\u00edd\u00e1 a\u017e 1\u00a0000\u2008ha p\u016fdy). Nejv\u00edce se na tomto rozsahu pod\u00edlely plochy p\u0161enice ozim\u00e9, je\u010dmene jarn\u00edho a\u00a0\u0159epky ozim\u00e9, jist\u00fd pod\u00edl m\u00e1 v\u0161ak samoz\u0159ejm\u011b tak\u00e9 v\u00fdb\u011br plodiny pro n\u00e1sleduj\u00edc\u00ed sezonu a\u00a0term\u00edn n\u00e1vazn\u00e9ho set\u00ed. Navazuj\u00edc\u00ed plodinou byla v\u00a0roce 2015 \u010dasto pr\u00e1v\u011b \u0159epka ozim\u00e1 (<em>obr. 5<\/em>). U\u00a0\u0159epky p\u011bstovan\u00e9 v\u00a0sezon\u011b 2015 doch\u00e1z\u00ed k\u00a0n\u00e1r\u016fstu rozsahu hol\u00e9 p\u016fdy na p\u0159elomu \u010dervna a\u00a0\u010dervence tak\u00e9 z\u00a0d\u016fvodu rychl\u00e9ho zr\u00e1n\u00ed a\u00a0\u010dasn\u00e9 sklizn\u011b (a\u00a0p\u0159\u00edpadn\u00e9 n\u00e1vazn\u00e9 kultivace pozemk\u016f).<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-6.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"461\" class=\"alignnone size-full wp-image-6164 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-6.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-6.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-6-300x173.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-6-768x443.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/461;\" \/><\/a>\n<h6>Obr. 6. Celkov\u00e1 a\u00a0procentn\u00ed v\u00fdm\u011bra hol\u00e9 p\u016fdy pro jednotliv\u00e9 plodiny v\u00a0roce 2015<br \/>\nFig. 6. The total and percentage extent of bare soil for different crops over entire target area in the year 2015<\/h6>\n<p>V\u00a0roce 2016 je na pozemc\u00edch b\u011bhem kv\u011btna a\u00a0\u010dervna jen minimum hol\u00e9 p\u016fdy. Rychl\u00fd n\u00e1r\u016fst plochy hol\u00e9 p\u016fdy v\u00a0srpnu je pak op\u011bt zp\u016fsoben v\u00fdsevem ozim\u00e9 \u0159epky. Nejv\u00edce se na ploch\u00e1ch hol\u00e9 p\u016fdy v\u00a0tomto roce pod\u00edl\u00ed porosty p\u0161enice ozim\u00e9, hrachu set\u00e9ho, triticale a\u00a0je\u010dmene jarn\u00edho. Rok 2017 je pak z\u00a0tohoto pohledu nejp\u0159\u00edzniv\u011bj\u0161\u00ed. Rozsah hol\u00e9 p\u016fdy na pozemc\u00edch je b\u011bhem rizikov\u00e9 \u010d\u00e1sti vegeta\u010dn\u00ed sezony minim\u00e1ln\u00ed, v\u00a0srpnu dosahuje 20\u00a0% (cca 300\u2008ha).<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-7.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"461\" class=\"alignnone size-full wp-image-6166 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-7.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-7.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-7-300x173.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-7-768x443.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/461;\" \/><\/a>\n<h6>Obr. 7. Celkov\u00e1 a\u00a0procentn\u00ed v\u00fdm\u011bra hol\u00e9 p\u016fdy pro jednotliv\u00e9 plodiny v\u00a0roce 2016<br \/>\nFig. 7. The total and percentage extent of bare soil for different crops over entire target area in the year 2016<\/h6>\n<h3>Dlouhodob\u00fd pr\u016fm\u011brn\u00fd erozn\u00ed smyv<\/h3>\n<p>V\u00fdsledkem v\u00fdpo\u010dtu jsou mapy erozn\u00edho rizika ve form\u011b rastrov\u00fdch vrstev GIS. V\u00fdstupn\u00ed d\u00e9lka hrany pixelu byla zvolena 5\u2008m, co\u017e je b\u011b\u017en\u00fd standard odpov\u00eddaj\u00edc\u00ed kvalit\u011b vstupn\u00edch podklad\u016f. V\u00fdsledky t\u00e9to anal\u00fdzy mohou odhalit probl\u00e9mov\u00e1 m\u00edsta na zem\u011bd\u011blsk\u00fdch pozemc\u00edch. Jedn\u00e1 se p\u0159edev\u0161\u00edm o\u00a0m\u00edsta, kde p\u0159i sr\u00e1\u017ekov\u00fdch ud\u00e1lostech hroz\u00ed vznik povrchov\u00e9ho odtoku a\u00a0p\u016fdn\u00edho smyvu. Na t\u011bchto m\u00edstech m\u016f\u017ee doch\u00e1zet k\u00a0po\u0161kozov\u00e1n\u00ed vzch\u00e1zej\u00edc\u00ed vegetace, p\u0159\u00edpadn\u011b na n\u00ed\u017ee le\u017e\u00edc\u00edch m\u00edstech k\u00a0redepozici materi\u00e1lu.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-8.jpg\" rel=\"shadowbox[sbpost-6242];player=img;\"><img decoding=\"async\" width=\"800\" height=\"461\" class=\"alignnone size-full wp-image-6168 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-8.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-8.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-8-300x173.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2019\/04\/Krasa-8-768x443.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/461;\" \/><\/a>\n<h6>Obr. 8. Celkov\u00e1 a\u00a0procentn\u00ed v\u00fdm\u011bra hol\u00e9 p\u016fdy pro jednotliv\u00e9 plodiny v\u00a0roce 2017<br \/>\nFig. 8. The total and percentage extent of bare soil for different crops over entire target area in the year 2017<\/h6>\n<p>Z\u00a0erozn\u00edch map jsme se pokusili vy\u010d\u00edst spojitost mezi v\u00fdskytem p\u016fdy bez vegetace a\u00a0hodnotou erozn\u00edho rizika. Na erozn\u00edch map\u00e1ch z\u00a0let 2015 a\u00a02016 n\u011bkter\u00e9 rizikov\u00e9 oblasti odpov\u00eddaly hol\u00fdm p\u016fd\u00e1m ji\u017e v\u00a0obdob\u00ed vegeta\u010dn\u00edho r\u016fstu. Pro rok 2017 se oblasti s\u00a0v\u00fdskytem p\u016fdy bez vegetace a\u00a0s\u00a0vy\u0161\u0161\u00ed hodnotou erozn\u00edho smyvu m\u00edjely. Statisticky byla vazba mezi erozn\u011b rizikov\u00fdmi pozemky a\u00a0v\u00fdskytem hol\u00e9 p\u016fdy v\u00a0letn\u00edm obdob\u00ed za roky 2015\u20132017 nev\u00fdznamn\u00e1. Pro takov\u00e9 porovn\u00e1n\u00ed by v\u0161ak bylo t\u0159eba podstatn\u011b del\u0161\u00ed sledovan\u00e9 obdob\u00ed.<\/p>\n<h2>Z\u00e1v\u011br<\/h2>\n<p>Data o\u00a0pozemc\u00edch a\u00a0jejich \u010d\u00e1stech bez vegeta\u010dn\u00edho pokryvu v\u00a0kombinaci se sr\u00e1\u017ekov\u00fdmi pr\u016fb\u011bhy erozn\u011b rizikov\u00fdch de\u0161\u0165\u016f jsou vstupem do procesn\u00edch model\u016f ur\u010duj\u00edc\u00edch hodnoty smyvu a\u00a0transportu splavenin. Zem\u011bd\u011blsk\u00e9 podniky informaci o\u00a0term\u00ednech vlastn\u00edch agrotechnick\u00fdch operac\u00ed v\u00a0aktu\u00e1ln\u00edm \u010dase samoz\u0159ejm\u011b maj\u00ed a\u00a0eviduj\u00ed, ale jejich ur\u010dov\u00e1n\u00ed pro \u0161ir\u0161\u00ed regiony je obt\u00ed\u017en\u00e9, vzhledem k\u00a0nutnosti z\u00edsk\u00e1vat je zp\u011btn\u00fdm \u0161et\u0159en\u00edm u\u00a0jednotliv\u00fdch podnik\u016f. Informace o\u00a0v\u00fdvoji rozsahu hol\u00fdch p\u016fd b\u011bhem roku je pak mo\u017eno efektivn\u011b z\u00edskat pomoc\u00ed\u00a0dat d\u00e1lkov\u00e9ho pr\u016fzkumu Zem\u011b.<\/p>\n<p>V\u00fdsledky proveden\u00e9 anal\u00fdzy mohou krom\u011b potvrzen\u00ed v\u00fdskytu hol\u00fdch p\u016fd t\u011bsn\u011b po term\u00ednu set\u00ed a\u00a0ur\u010den\u00ed rychlosti zapojen\u00ed porostu set\u00fdch plodin odhalit tak\u00e9 probl\u00e9mov\u00e1 m\u00edsta na zem\u011bd\u011blsk\u00fdch pozemc\u00edch. Jedn\u00e1 se p\u0159edev\u0161\u00edm o\u00a0m\u00edsta, kde rostliny \u0161patn\u011b vzch\u00e1z\u00ed. Na t\u011bchto m\u00edstech ji\u017e mohlo doj\u00edt k\u00a0destrukci \u00farodn\u00e9 svrchn\u00ed vrstvy p\u016fdy, m\u00edsta mohou b\u00fdt zamok\u0159en\u00e1, \u010di zde do\u0161lo k\u00a0redepozici erozn\u00edho splachu. Identifikac\u00ed t\u011bchto m\u00edst lze u\u010dinit prvn\u00ed krok k\u00a0n\u00e1prav\u011b a\u00a0op\u011bt za\u010d\u00edt pole plnohodnotn\u011b u\u017e\u00edvat. T\u00edmto lze zv\u00fd\u0161it hektarov\u00e9 v\u00fdnosy plodin, p\u0159\u00edpadn\u011b upravit d\u011blen\u00ed p\u016fdn\u00edch blok\u016f. Ide\u00e1ln\u00edm postupem je sestavit z\u00a0dru\u017eicov\u00fdch sc\u00e9n dlouhodob\u00e9 \u010dasov\u00e9 \u0159ady v\u00a0odpov\u00eddaj\u00edc\u00edch si vegeta\u010dn\u00edch obdob\u00edch. Pro komplexn\u00ed popis situace na pozemc\u00edch je vhodn\u00e9 v\u00fdsledky vyhodnocen\u00ed dat d\u00e1lkov\u00e9ho pr\u016fzkumu kombinovat s\u00a0daty o\u00a0konkr\u00e9tn\u00edch plodin\u00e1ch a\u00a0datech v\u00fdsevu (resp. sklizn\u011b). Tato data by mohla b\u00fdt pro \u0159adu region\u016f snadno sou\u010d\u00e1st\u00ed LPIS, nebo\u0165 podniky plodiny vykazuj\u00ed (by\u0165 ne p\u0159\u00edmo ve vztahu ke konkr\u00e9tn\u00edmu bloku) a\u00a0obvykle si vedou p\u0159esnou evidenci. Bohu\u017eel pro v\u00fdzkum nejsou takov\u00e1 data standardn\u011b dostupn\u00e1, st\u00e1le je tedy t\u0159eba se obracet na jednotliv\u00e9 podniky a\u00a0zaji\u0161\u0165ovat osevn\u00ed postupy individu\u00e1ln\u011b.<\/p>\n<p>Prostorov\u00e1 variabilita porostu je rovn\u011b\u017e v\u00fdborn\u011b evidov\u00e1na ve skliz\u0148ov\u00fdch map\u00e1ch z\u00edskan\u00fdch p\u0159\u00edmo ze stroj\u016f pracuj\u00edc\u00edch v\u00a0re\u017eimu p\u0159esn\u00e9ho zem\u011bd\u011blstv\u00ed, nicm\u00e9n\u011b tyto \u00fadaje se nevztahuj\u00ed k\u00a0inici\u00e1ln\u00edm f\u00e1z\u00edm porostu, kter\u00e9 je t\u0159eba zejm\u00e9na sledovat p\u0159i v\u00fdpo\u010dtech erozn\u00edho rizika. Zde se do budoucna nab\u00edz\u00ed vyhodnocen\u00ed prostorov\u011b variabiln\u00edch dat aplikace hnojiv.<\/p>\n<p>Testov\u00e1n\u00ed dostupnosti bezobla\u010dn\u00fdch sc\u00e9n pro z\u00e1jmovou lokalitu za roky 2015\u20132017 uk\u00e1zalo na st\u00e1le vysok\u00e9 riziko jejich nedostate\u010dn\u00e9 dostupnosti v\u00a0obdob\u00ed n\u00e1stupu p\u0159\u00edvalov\u00fdch sr\u00e1\u017eek a\u00a0rychl\u00e9ho rozvoje vegeta\u010dn\u00edho pokryvu v\u00a0rizikov\u00e9m obdob\u00ed \u010derven\u2013srpen. Z\u00e1sadn\u00ed pokrok nastal v\u00a0roce 2017, kdy byla vypu\u0161t\u011bna dru\u017eice Sentinel 2\u2008B a\u00a0dosavadn\u00ed problematick\u00e1 dostupnost dostate\u010dn\u00e9ho mno\u017estv\u00ed dat v\u00a0ucelen\u00fdch \u010dasov\u00fdch \u0159ad\u00e1ch se v\u00fdrazn\u011b zlep\u0161ila. Rovn\u011b\u017e trojn\u00e1sobn\u00e9 prostorov\u00e9 rozli\u0161en\u00ed a\u00a0vylep\u0161en\u00e9 spektr\u00e1ln\u00ed rozli\u0161en\u00ed v\u00a0oblasti red-edge umo\u017e\u0148uje podstatn\u011b kvalitn\u011bj\u0161\u00ed klasifikace vegeta\u010dn\u00edch index\u016f.<\/p>\n<p>Kombinaci dru\u017eicov\u00fdch dat a\u00a0informac\u00ed o\u00a0term\u00ednech agrotechnick\u00fdch z\u00e1sah\u016f lze vyu\u017e\u00edt v\u00a0protierozn\u00ed ochran\u011b a\u00a0k\u00a0optimalizaci p\u011bstebn\u00edch postup\u016f s\u00a0vyu\u017eit\u00edm precizn\u00edho zem\u011bd\u011blstv\u00ed, p\u0159edev\u0161\u00edm se jedn\u00e1 o\u00a0variabilitu pou\u017eit\u00ed nutrient\u016f (p\u0159\u00edpadn\u011b herbicid\u016f i\u00a0pesticid\u016f), nebo o\u00a0zlep\u0161en\u00ed prostorov\u00e9 variability v\u00fdsevu a\u00a0trajektori\u00ed pojezd\u016f na zem\u011bd\u011blsk\u00fdch pozemc\u00edch.<\/p>\n<h3>Pod\u011bkov\u00e1n\u00ed<\/h3>\n<p><em>Auto\u0159i d\u011bkuj\u00ed Ing. V\u00edt\u011bzslavu Kr\u010dkovi, Ph.D., a\u00a0podniku AGRA \u0158isuty, s. r. o., za poskytnut\u00e1 data a\u00a0dlouhodobou spolupr\u00e1ci p\u0159i ter\u00e9nn\u00edch kampan\u00edch a\u00a0v\u00fdzkumu erozn\u00edch proces\u016f. \u010cl\u00e1nek byl p\u0159ipraven s\u00a0podporou projekt\u016f EIP Implementace nov\u00fdch a\u00a0inovovan\u00fdch technologi\u00ed precizn\u00edho zem\u011bd\u011blstv\u00ed do p\u011bstebn\u00edch syst\u00e9m\u016f, registra\u010dn\u00ed \u010d\u00edslo 16\/003\/1611a\/120\/000095 a\u00a0QK1720289 V\u00fdvoj automatizovan\u00e9ho n\u00e1stroje pro optimalizaci monitoringu eroze zem\u011bd\u011blsk\u00e9 p\u016fdy pomoc\u00ed distan\u010dn\u00edch metod.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u010cl\u00e1nek popisuje metodu, zdrojov\u00e1 data i v\u00fdsledky anal\u00fdzy erozn\u00ed ohro\u017eenosti podle nov\u00e9 metodiky vyu\u017eit\u00ed d\u00e1lkov\u00e9ho pr\u016fzkumu Zem\u011b pro ochranu zem\u011bd\u011blsk\u00e9 p\u016fdy. Metoda je testov\u00e1na na pozemc\u00edch AGRA \u0158isuty, s. r. o. Pro zji\u0161t\u011bn\u00ed p\u0159\u00edtomnosti vegeta\u010dn\u00edho pokryvu na jednotliv\u00fdch p\u016fdn\u00edch bloc\u00edch \u010di jejich \u010d\u00e1stech jsou vyu\u017e\u00edv\u00e1na data z dru\u017eic Landsat 8 a Sentinel 2. <\/p>\n","protected":false},"author":8,"featured_media":6147,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[91,86],"tags":[1549,279,1550,712],"coauthors":[692,1537,1538],"class_list":["post-6242","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-applied-ecology","category-hydraulics-hydrology-and-hydrogeology","tag-dalkovy-pruzkum-zeme","tag-gis","tag-precizni-zemedelstvi","tag-vodni-eroze"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/6242","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=6242"}],"version-history":[{"count":4,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/6242\/revisions"}],"predecessor-version":[{"id":30508,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/6242\/revisions\/30508"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/6147"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=6242"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=6242"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=6242"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=6242"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}