Secondary language: |
English |
Secondary title: |
Hydrological controls of nutrient mobilization in watersheds |
Secondary abstract: |
The doctoral dissertation deals with the temporal dynamics of the nutrient mobilization from a forested watershed with the emphasis on the definition and analysis of the hydrological mechanisms responsible for the regulation of observed responses of the streamwater nitrate concentrations and the amounts of the flushed nitrate. In 2006 and 2007 we continuously monitored the changeability of hydrometeorological conditions on rain gauges, limnigraphs and meteorological station on the studied area, the Padež stream forested watershed. The measurements of the hydrometeorological conditions were periodically supplemented by the continuous measurements of the streamwater chemistry in different seasonal and hydrological settings. The measurements of the streamwater nitrate concentrations during the hydrological events disclosed a considerable but variable responsiveness of the concentration to the hydrological conditions. In spite of the variability of the hydrological conditions, a seasonal influence could be recognised which has a prevailing role in regulating the intensity of biogeochemical transformations of nitrogen compounds, their further availability to mobilize under the impact of the hydrological mechanisms and respond to rainfall events. In the scope of the conceptual explanation of nitrate flushing, the perceived temporal patterns of the hydrograph and peak streamwater concentration formation were linked to the temporal frequency of the soil profile saturation deficit oscillations and associated changeability of spatial extension of the saturated variable areas. An extensive database obtained through continuous measurements was used for the application of the data mining methods. Using the algorithm M5 which, based on the recognised relations between the data builds the model trees and classification rules, we supplemented our domain knowledge of the nitrate flushing from the forested watershed and modelled the streamwater nitrate concentration. Additionally, we calculated the mass flux of the nitrate which is annually washed from the studied forested watershed. |
Secondary keywords: |
hydrology;nutrients;continuous measurements;the Padež stream watershed;data mining;modelling; |
URN: |
http://www.dlib.si/?urn=URN:NBN:SI:doc-KQ51WATK |
File type: |
application/pdf |
Type (COBISS): |
Dissertation |
Thesis comment: |
Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo |
Pages: |
XVI, 206 str, pril. |
Type (ePrints): |
thesis |
Title (ePrints): |
Hydrological controls of nutrient mobilization in watersheds |
Keywords (ePrints): |
hidrologija;hranila;zvezne meritve;porečje Padeža;rudarjenje podatkov;modeliranje |
Keywords (ePrints, secondary language): |
hydrology;nutrients;continuous measurements;the Padež stream watershed;data mining;modelling |
Abstract (ePrints): |
Doktorska disertacija obravnava časovno dinamiko sproščanja hranil z gozdnatega prispevnega območja s poudarkom na opredelitvi in analizi hidroloških mehanizmov, odgovornih za uravnavanje opazovanih odzivov koncentracije nitratnega dušika v vodotoku, ter količin spranega nitratnega dušika. Na območju obravnave, gozdnatem prispevnem območju potoka Padež, smo v letih 2006 in 2007 zvezno spremljali hidrometeorološke razmere na več dežemerih in vodomernih postajah ter meteorološki postaji. Meritve hidrometeoroloških razmer smo periodično dopolnili z zveznimi meritvami kemizma vode v vodotoku v različnih letnih časih in hidroloških razmerah. Zvezne meritve koncentracije nitratnega dušika v vodotoku v času padavinskih dogodkov razkrivajo precejšnjo, a spremenljivo odzivnost koncentracije na hidrološke razmere. Navkljub pestrosti opazovanih hidroloških razmer se v merjenih koncentracijah nitratnega dušika odraža sezonski vpliv, ki ima prevladujočo vlogo pri regulaciji intenzivnosti biogeokemijskih transformacij dušikovih spojin, njihovi nadaljnji razpoložljivosti za mobilizacijo pod vplivom hidroloških mehanizmov ter s tem odzivnosti na padavinske dogodke. V okviru konceptualizacije spiranja nitratnega dušika smo zaznane časovne vzorce formacije hidrogramov odtoka ter koničnih koncentracij nitratnega dušika v vodotoku navezali na časovno frekvenco nihanj zasičene cone talnega profila in s tem povezane spremenljivosti prostorske razsežnosti območij zasičenega talnega profila. Obsežno bazo podatkov, pridobljenih v okviru zveznih meritev, smo uporabili za aplikacijo metod rudarjenja po podatkih. Z algoritmom M5, ki na podlagi prepoznanih zvez med podatki gradi modelna drevesa oz. nize klasifikacijskih pravil, smo dopolnili naše domensko poznavanje spiranja nitratnega dušika z gozdnatega prispevnega območja in modelirali koncentracijo nitratnega dušika v vodotoku ter opredelili letno masno bilanco sproščene količine nitratnega dušika z gozdnatega porečja. |
Abstract (ePrints, secondary language): |
The doctoral dissertation deals with the temporal dynamics of the nutrient mobilization from a forested watershed with the emphasis on the definition and analysis of the hydrological mechanisms responsible for the regulation of observed responses of the streamwater nitrate concentrations and the amounts of the flushed nitrate. In 2006 and 2007 we continuously monitored the changeability of hydrometeorological conditions on rain gauges, limnigraphs and meteorological station on the studied area, the Padež stream forested watershed. The measurements of the hydrometeorological conditions were periodically supplemented by the continuous measurements of the streamwater chemistry in different seasonal and hydrological settings. The measurements of the streamwater nitrate concentrations during the hydrological events disclosed a considerable but variable responsiveness of the concentration to the hydrological conditions. In spite of the variability of the hydrological conditions, a seasonal influence could be recognised which has a prevailing role in regulating the intensity of biogeochemical transformations of nitrogen compounds, their further availability to mobilize under the impact of the hydrological mechanisms and respond to rainfall events. In the scope of the conceptual explanation of nitrate flushing, the perceived temporal patterns of the hydrograph and peak streamwater concentration formation were linked to the temporal frequency of the soil profile saturation deficit oscillations and associated changeability of spatial extension of the saturated variable areas. An extensive database obtained through continuous measurements was used for the application of the data mining methods. Using the algorithm M5 which, based on the recognised relations between the data builds the model trees and classification rules, we supplemented our domain knowledge of the nitrate flushing from the forested watershed and modelled the streamwater nitrate concentration. Additionally, we calculated the mass flux of the nitrate which is annually washed from the studied forested watershed. |
Keywords (ePrints, secondary language): |
hydrology;nutrients;continuous measurements;the Padež stream watershed;data mining;modelling |
ID: |
8311052 |