Vpliv prestrezanja padavin na erozijo

Autor: Zore, Anita
Přispěvatelé: Šraj, Mojca
Jazyk: slovinština
Rok vydání: 2020
Předmět:
Popis: Erozivnost padavin v svetovnem pogledu predstavlja velik izziv. Mikrostruktura padavin je ena ključnih lastnosti padavin, ki vpliva na gozdno vodno bilanco in erozijo tal, a se v raziskavah le redko upošteva. V magistrskem delu je obravnavano 14 mesečno obdobje meritev padavin s pomočjo dveh disdrometrov nad in pod drevesno krošnjo breze. Iz pridobljenih podatkov smo izločili erozivne padavinske dogodke, izračunali trajanje posameznega dogodka, pridobili količino akumuliranih padavin in določili podatke o velikosti, hitrosti in številu dežnih kapljic nad krošnjo in pod njo. Izračunali smo tudi kinetično energijo padavin in erozijski dejavnik R posameznega padavinskega dogodka ter izvedli primerjavo potencialne izgube tal v primeru padavin nad in pod drevesno krošnjo. Rezultati kažejo, da breza z daljšanjem trajanja padavinskega dogodka prepušča večjo količino padavin. V času vegetacije je prestregla 33 %, v času mirovanja pa 25 % padavin. Velikosti in hitrosti kapljic so bile v celotnem obravnavanem obdobju v splošnem nad drevesno krošnjo večje kot pod njo, a so v večji meri ohranile svojo velikost in hitrost pri prehodu skozi krošnjo v času mirovanja. Vrednost KE dežnih kapljic se je v času mirovanja pri prehodu skozi krošnjo ohranila, v času vegetacije pa se je zmanjšala za 31 %. Dejavnik erozivnosti padavin R se je v času vegetacije pod drevesno krošnjo zmanjšal za 50 %, v času mirovanja pa je bila vrednost pod drevesno krošnjo manjša za 21 %. The rainfall erosivity is a worldwide challenge. Rainfall microstructure is one of the key properties of precipitation, which affects forest water balance and soil erosion, but it is rarely considered during the research processes. The master’s thesis deals with the 14 - month period of precipitation measurements using two disdrometers above and below the birch tree canopy. We excluded erosive precipitation events from the obtained data, calculated the duration of individual events, obtained the amount of accumulated precipitation and determined data on the drop size, velocity and number of raindrops detected above and below the canopy. We also calculated the kinetic energy of precipitation and the erosion factor R of individual precipitation events and performed a comparison of potential soil loss in the case of precipitation above and below the tree canopy. The results show that throughfall under the birch increasing with a longer duration of the precipitation event. The interception by the birch canopy was 33% of precipitation during the vegetation period, and 25% during the dormant period. Droplet sizes and velocities were generally higher above the canopy than below it throughout the period considered, but they largely retained their size and velocity as they passed through the canopy during the dormancy period. The kinetic energy of raindrops was maintained during the dormancy period as they passed through the canopy, while it decreased by 31% during the growing season. During the vegetation period, the erosion factor R decreased by 50% when passing through the canopy, and during the dormancy period the value under the canopy decreased by 21%.
Databáze: OpenAIRE
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