Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
Analysis of the influence of catchment characteristics on base flow index |
Sekundarni povzetek: |
Base flow is an important segment of total runoff. It represents minimum flow during dry season and also prolongs flood wave after quick flow has already been ended. That is why it is very important to consider it at hydrological modeling. Base flow is difficult to define. It could not be directly gauged in nature, we can only use indirect methods. It could also be determinated from streamflow data, from stream hydrograph. But how can we estimate BFI if we don't have streamflow data?
In the first part of this thesis base flow is defined and explained and influences on base flow are presented. Different methods for base flow determination and calculation are also presented. Three basic concepts for determination of base flow from streamflow data are introduced. These concepts are: direct determination from stream flow data, frequency analysis and base flow recession analysis. Methods that are used on field like electrical conductivity, tracer analysis or gauging of groundwater levels are also presented. For every concept of base flow determination a few methods are described. In this part is also a description of program BFI of Windows, which is used for BFI values calculation.
In the second part of this thesis the analysis of the influence of chatchment characteristics on BFI are made. This analysis includes 20 chatchments in Slovenia. We analysed influence of geographical and climate characteristics, land cover, geological structure, hydrogeological structure and pedological structure of chatchements. Results showed that chatchment slope, area, portion of agricultural land and evaporation have the most significante influence on BFI. Based on the results of such analysis we can create mathematical models for estimation of BFI for ungauged chatchments. |
Sekundarne ključne besede: |
baseflow;hydrograph;determination of base flow;base flow index (BFI);chatchment characteristics;influence on BFI;BFI for Windows |
Vrsta datoteke: |
application/pdf |
Vrsta dela (COBISS): |
Diplomsko delo |
Komentar na gradivo: |
Univ. v Ljubljani, Fak. za gradbeništvo in geodezijo |
Strani: |
XII, 93 str. |
Vrsta dela (ePrints): |
thesis |
Naslov (ePrints): |
Analysis of the influence of catchment characteristics on base flow index |
Ključne besede (ePrints): |
bazni odtok;hidrogram odtoka;določanje baznega odtoka;indeks baznega odtoka (BFI);lastnosti porečja;vpliv na BFI;BFI for Windows |
Ključne besede (ePrints, sekundarni jezik): |
baseflow;hydrograph;determination of base flow;base flow index (BFI);chatchment characteristics;influence on BFI;BFI for Windows |
Povzetek (ePrints): |
Bazni odtok je pomemben del celotnega pretoka vodotoka, predstavlja minimalni pretok v obdobjih brez padavin ali pa podaljšuje poplavni val, ko je površinski odtok že končan. Zatorej ga je potrebno upoštevati pri hidrološkem modeliranju. Bazni odtok je težko določljiv, v naravi ga lahko merimo zgolj posredno. Lahko ga ocenimo iz podatkov o pretoku vodotoka oz. s pomočjo hidrograma pretoka. Za izračun baznega odtoka ali indeksa baznega odtoka (BFI) potrebujemo podatke o dnevnih pretokih. Kako pa lahko ocenimo BFI za porečje, na katerem nimamo podatkov o dnevnih pretokih?
V prvem delu diplomske naloge je opisan bazni odtok, principi po katerih deluje in faktorji, ki vplivajo na količino in lastnosti baznega odtoka. Predstavljeni in opisani so trije glavni postopki določevanja baznega odtoka iz podatkov o pretoku ( neposredno določanje baznega odtoka, analize pogostosti in analize krivulje upadanja baznega odtoka) ter določanje baznega odtoka s pomočjo merjenja v naravi (merjenje električne prevodnosti, sledenje kemičnim spojinam ali elementom, merjenje višine podtalnice). Pri vseh načinih je podrobno opisanih nekaj najpogosteje uporabljenih metod. Opisan je tudi program BFI for Windows, s katerim smo izračunali vrednosti BFI za izbrana porečja.
V drugem delu diplomske naloge je narejena analiza vpliva različnih lastnosti porečja na BFI. V analizi je vključenih 20 porečij Slovenije. Analiziran je bil vpliv geografskih in klimatskih lastnosti, pokrovnosti tal, geološke sestave tal, hidrogeoloških tipov tal ter pedološke sestave tal. Ugotovlili smo, da imajo največji vpliv na BFI naklon porečja, površina, delež kmetijskih površin in izhlapevanje. Na podlagi ugotovitev iz takih analiz lahko izdelamo matematične modele za določitev oz. oceno BFI za porečja, na katerih nimamo podatkov o dnevnih pretokih. |
Povzetek (ePrints, sekundarni jezik): |
Base flow is an important segment of total runoff. It represents minimum flow during dry season and also prolongs flood wave after quick flow has already been ended. That is why it is very important to consider it at hydrological modeling. Base flow is difficult to define. It could not be directly gauged in nature, we can only use indirect methods. It could also be determinated from streamflow data, from stream hydrograph. But how can we estimate BFI if we don't have streamflow data?
In the first part of this thesis base flow is defined and explained and influences on base flow are presented. Different methods for base flow determination and calculation are also presented. Three basic concepts for determination of base flow from streamflow data are introduced. These concepts are: direct determination from stream flow data, frequency analysis and base flow recession analysis. Methods that are used on field like electrical conductivity, tracer analysis or gauging of groundwater levels are also presented. For every concept of base flow determination a few methods are described. In this part is also a description of program BFI of Windows, which is used for BFI values calculation.
In the second part of this thesis the analysis of the influence of chatchment characteristics on BFI are made. This analysis includes 20 chatchments in Slovenia. We analysed influence of geographical and climate characteristics, land cover, geological structure, hydrogeological structure and pedological structure of chatchements. Results showed that chatchment slope, area, portion of agricultural land and evaporation have the most significante influence on BFI. Based on the results of such analysis we can create mathematical models for estimation of BFI for ungauged chatchments. |
Ključne besede (ePrints, sekundarni jezik): |
baseflow;hydrograph;determination of base flow;base flow index (BFI);chatchment characteristics;influence on BFI;BFI for Windows |
ID: |
8312538 |