LETNIK 17, ĹĄt. 25 (julij 1999) / VOLUME 17, No.25 (July 1999) (full paper pdf)
avtor/author: | mag. IRENA CVITANIÄ, univ.dipl.inĹž.kem.tehn. / M. Civil Eng., Diploma in Chemical Techn. |
zaposlen/employed: |
HidrometeoroloĹĄki zavod RS /
Hydrometeorological Institute of Slovenia, Vojkova 1b, SI â 1000 Ljubljana |
naslov/title:
|
ANALIZA MOŽNIH KAKOVOSTNIH SPREMEMB SAVE V AKUMULACIJI HE VRHOVO
V POVPREÄNIH IN EKSTREMNIH HIDROLOĹ KIH POGOJIH S POMOÄJO MATEMATIÄNEGA MODELA / ANALYSIS OF POSSIBLE QUALITY CHANGES OF RIVER SAVA IN THE VRHOVO IMPOUNDMENT IN AVERAGE AND EXTREME HYDROLOGICAL CONDITIONS WITH MATHEMATICAL MODEL povzetek magistrskega dela / summary of the Master Thesis Fakulteta za gradbeniĹĄtvo in geodezijo Univerze v Ljubljani / Faculty of Civil and Geodetic Engineering, University of Ljubljana |
IzvleÄek
Izgradnja hidroelektrarne (HE) Vrhovo je povzroÄila nastanek reÄnega
akumulacijskega jezera na reki Savi in s tem spremembo njenega naravnega vodnega reĹžima,
ki se odraĹža tudi v spremenjenih pogojih nebioloĹĄkih in bioloĹĄkih procesov
samoÄiĹĄÄenja vode in tako vpliva na njene kakovostne spremembe. Posledice energetske
zajezitve reke na kakovost voda so lahko pozitivne ali negativne. V nalogi so obravnavani
procesi evtrofikacije, biokemiÄni in fizikalni procesi v rekah in jezerih, posledice
zajezitev rek ter teoretiÄni temelji matematiÄnega modeliranja in uporabljenega
veÄparameterskega enodimenzionalnega modela QUAL2E. Model je bil uporabljen za
modeliranje in napovedovanje moĹžnih sprememb kakovosti vode v nastali zajezitvi.
Opravljena je bila analiza obÄutljivosti modela. Ĺ tevilni parametri modela so bili
doloÄeni z umerjanjem modela tako, da je doseĹženo najboljĹĄe ujemanje rezultatov modela
z izmerjenim stanjem. Potrditev modela je bila izvedena z rezultati meritev v letih 1996
in 1998. Na temelju dobljenih rezultatov je bil model uporabljen za kvantitativne napovedi
raztopljenega kisika in biokemijske potrebe po kisiku v akumulaciji HE Vrhovo za ekstremne
in povpreÄne hidroloĹĄke pogoje. Glede na rezultate modela in terenske meritve, izvedene
pri nizkih pretokih in v pogojih poteka intenzivne primarne produkcije v zajezitvi, lahko
zakljuÄimo, da v akumulacijskem jezeru HE Vrhovo ne prihaja do prekomernega zniĹžanja
koncentracije raztopljenega kisika, ki bi povzroÄala negativne vplive na kakovost
zajezene vode.
KljuÄne besede: evtrofikacija, matematiÄni modeli, modeliranje kakovosti voda, povrĹĄinske vode, hidroelektrarna Vrhovo.
UDK 504.4:519.87:556.55(282.243.743)
Abstract
The river impoundment on the Sava River was formed as a consequence of the
construction of the Vrhovo Hydroelectric Power Plant (HEPP). The river impoundment changed
the natural water circulation of the Sava River, a disruption which is also reflected in
the changed conditions of the biological and non-biological self-purification processes in
the water. Thus, it influences the water quality of the Sava River. River impoundments can
affect water quality positively or negatively. This Thesis deals with the eutrophication,
biochemical and physical processes in rivers and lakes, the impacts of river impoundments,
the theoretical base of mathematical modelling and the employed multiparametric
one-dimensional model QUAL2E. The QUAL2E model was used to model and predict the possible
changes in water quality in the impoundment. A sensitivity analysis provided insight into
the model operation and showed how the results of the model change when changing separate
parameters. Many model parameters were determined by calibrating the model in such a
manner that the best agreement between the results of the model and the measured state was
achieved. The model validation was performed using the results of the measurements in 1996
and 1998. Based on the results obtained, the model was used for the quantitative
prediction of dissolved oxygen and biochemical oxygen demand in the Vrhovo impoundment for
extreme and average hydrological conditions. With regard to the model results and field
measurements performed at low discharges and under conditions of intensive primary
production in the dam, it can be concluded that an excessive decrease in concentrations of
dissolved oxygen which could have negative influence on the dammed water quality does not
appear in the Vrhovo impoundment.
Key words: eutrophication, mathematical models, water quality modelling, surface water, hydroelectric power station Vrhovo.
UDC 504.4:519.87:556.55(282.243.743)