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You searched for +publisher:"University of Oslo" +contributor:("Lena M. Tallaksen"). Showing records 1 – 3 of 3 total matches.

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University of Oslo

1. Gudmundsson, Lukas. Large-Scale Hydrology in Europe : Observed Patterns and Model Performance.

Degree: 2011, University of Oslo

In a changing climate, terrestrial water storages are of great interest as water availability impacts key aspects of ecosystem functioning. Thus, a better understanding of the variations of wet and dry periods will contribute to fully grasp processes of the earth system such as nutrient cycling and vegetation dynamics. Currently, river runoff from small, nearly natural, catchments is one of the few variables of the terrestrial water balance that is regularly monitored with detailed spatial and temporal coverage on large scales. River runoff, therefore, provides a foundation to approach European hydrology with respect to observed patterns on large scales, with regard to the ability of models to capture these. The analysis of observed river flow from small catchments, focused on the identification and description of spatial patterns of simultaneous temporal variations of runoff. These are dominated by large-scale variations of climatic variables but also altered by catchment processes. It was shown that time series of annual low, mean and high flows follow the same atmospheric drivers. The observation that high flows are more closely coupled to large scale atmospheric drivers than low flows, indicates the increasing influence of catchment properties on runoff under dry conditions. Further, it was shown that the low-frequency variability of European runoff is dominated by two opposing centres of simultaneous variations, such that dry years in the north are accompanied by wet years in the south. Large-scale hydrological models are simplified representations of our current perception of the terrestrial water balance on large scales. Quantification of the models strengths and weaknesses is the prerequisite for a reliable interpretation of simulation results. Model evaluations may also enable to detect shortcomings with model assumptions and thus enable a refinement of the current perception of hydrological systems. The ability of a multi model ensemble of nine large-scale hydrological models and the land surface scheme of a high resolution regional climate model to capture various aspects of runoff were assessed. In general high and mean flows were better captured than low flows, pointing toward deficiencies with the models representation of storage processes. The analysis of the multi model ensemble also showed that the mean of all model simulations generally provided a more robust and accurate estimator of continental scale variations of catchment runoff than any individual model. Advisors/Committee Members: Lena M. Tallaksen.

Subjects/Keywords: VDP::450

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Gudmundsson, L. (2011). Large-Scale Hydrology in Europe : Observed Patterns and Model Performance. (Thesis). University of Oslo. Retrieved from http://urn.nb.no/URN:NBN:no-30423 ; https://www.duo.uio.no/handle/10852/12332 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12332/3/dravhandling-gudmundsson.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Gudmundsson, Lukas. “Large-Scale Hydrology in Europe : Observed Patterns and Model Performance.” 2011. Thesis, University of Oslo. Accessed August 22, 2019. http://urn.nb.no/URN:NBN:no-30423 ; https://www.duo.uio.no/handle/10852/12332 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12332/3/dravhandling-gudmundsson.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Gudmundsson, Lukas. “Large-Scale Hydrology in Europe : Observed Patterns and Model Performance.” 2011. Web. 22 Aug 2019.

Vancouver:

Gudmundsson L. Large-Scale Hydrology in Europe : Observed Patterns and Model Performance. [Internet] [Thesis]. University of Oslo; 2011. [cited 2019 Aug 22]. Available from: http://urn.nb.no/URN:NBN:no-30423 ; https://www.duo.uio.no/handle/10852/12332 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12332/3/dravhandling-gudmundsson.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Gudmundsson L. Large-Scale Hydrology in Europe : Observed Patterns and Model Performance. [Thesis]. University of Oslo; 2011. Available from: http://urn.nb.no/URN:NBN:no-30423 ; https://www.duo.uio.no/handle/10852/12332 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12332/3/dravhandling-gudmundsson.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of Oslo

2. Trondsen, Elise. Evaluering av ulike metoder for innsjøfordampning : Forsøksområde Aursunden, Sør-Trøndelag.

Degree: 2008, University of Oslo

Fordampningsberegninger for Aursunden (690m.o.h.), Sør-Trøndelag, er utført for fordampningssesongen 2000. Instrumenteringen inkluderte en flåte med en metrologisk stasjon, en metrologisk stasjon nær sjøen, kontinuerlige målinger av sjøtemperatur og manuelle temperaturmålinger fra hele sjøen. Etter vindhendelser med døgnmiddel over 4msP-1P var sjøen fullstendig omblandet. Vindhastighetene på flåten, 2,44m over overflaten, var omtrent 1,5 ganger høyere enn ved den nærliggende vindmåleren på 10m. Av de fire metodene som er evaluert har massetransport-metoden visst å ha lavest usikkerheter, med 45 %, etterfulgt av Penmans metode, med 50 %. Energibalanse-metoden hadde store usikkerheter assosiert med atmosfærens emissivitet og dette gjorde metoden til den mest usikre, med 95 %. Vannbalanse-metoden var ikke mulig å evaluere med de tilgjengelige dataene. For perioden 24.juni til 15.september er fordampningen beregnet å være (i mm) 215,4 ved massetransport-metoden, 157,7 ved Penmans metode og 193,5 ved energibalanse-metoden. Metodene måtte evalueres for perioder på minst fire uker for å gi resultater med godt samsvar. Advisors/Committee Members: Lena M. Tallaksen.

Subjects/Keywords: hydrologi massetransport mass transfer energibalanse Penmans metode kombinasjonsmetoden; VDP::450

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Trondsen, E. (2008). Evaluering av ulike metoder for innsjøfordampning : Forsøksområde Aursunden, Sør-Trøndelag. (Thesis). University of Oslo. Retrieved from http://urn.nb.no/URN:NBN:no-19946 ; https://www.duo.uio.no/handle/10852/12467

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Trondsen, Elise. “Evaluering av ulike metoder for innsjøfordampning : Forsøksområde Aursunden, Sør-Trøndelag.” 2008. Thesis, University of Oslo. Accessed August 22, 2019. http://urn.nb.no/URN:NBN:no-19946 ; https://www.duo.uio.no/handle/10852/12467.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Trondsen, Elise. “Evaluering av ulike metoder for innsjøfordampning : Forsøksområde Aursunden, Sør-Trøndelag.” 2008. Web. 22 Aug 2019.

Vancouver:

Trondsen E. Evaluering av ulike metoder for innsjøfordampning : Forsøksområde Aursunden, Sør-Trøndelag. [Internet] [Thesis]. University of Oslo; 2008. [cited 2019 Aug 22]. Available from: http://urn.nb.no/URN:NBN:no-19946 ; https://www.duo.uio.no/handle/10852/12467.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Trondsen E. Evaluering av ulike metoder for innsjøfordampning : Forsøksområde Aursunden, Sør-Trøndelag. [Thesis]. University of Oslo; 2008. Available from: http://urn.nb.no/URN:NBN:no-19946 ; https://www.duo.uio.no/handle/10852/12467

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


University of Oslo

3. Glad, Per Alve. Meteorological and hydrological conditions leading to severe regional drought in Malawi.

Degree: 2010, University of Oslo

Drought is a natural feature of the climate usually associated with dry and warm weather over an extended period of time causing less than normal water available at the land surface. The development of a drought is a slow process and it is often hard to detect early. Malawi represents a country that is highly dependent on agriculture and where data scarcity is a common problem. This study examines the applicability of modelled monthly precipitation data in drought assessment by comparing observed and modelled precipitation series in Malawi. The study reveals a high average correlation (~0.86) between modelled and observed data, suggesting that the modelled data provides a valuable tool in drought studies. A simple but novel method, Regional Drought Index, combining SPI and modelled data is introduced to examine drought on a regional scale. The method recognizes the severe droughts of the region documented in the literature. Standardized Precipitation Index and Standardized Runoff Index series are compared to investigate whether meteorological anomalies can be expected to characterize streamflow in rivers with different catchment sizes. The comparison of meteorological and hydrological monthly data suggests that the response time of the catchments increases with increasing catchment area. The ability to recognize runoff variability was highest for catchment sizes larger than 2000 km2, whereas for the smaller catchments the agreement between the two was low. Advisors/Committee Members: Lena M. Tallaksen, Hege Hisdal.

Subjects/Keywords: VDP::450

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Glad, P. A. (2010). Meteorological and hydrological conditions leading to severe regional drought in Malawi. (Thesis). University of Oslo. Retrieved from http://urn.nb.no/URN:NBN:no-26053 ; https://www.duo.uio.no/handle/10852/12663 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12663/1/PDF_of_Master_thesis%5B1%5D.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Glad, Per Alve. “Meteorological and hydrological conditions leading to severe regional drought in Malawi.” 2010. Thesis, University of Oslo. Accessed August 22, 2019. http://urn.nb.no/URN:NBN:no-26053 ; https://www.duo.uio.no/handle/10852/12663 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12663/1/PDF_of_Master_thesis%5B1%5D.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Glad, Per Alve. “Meteorological and hydrological conditions leading to severe regional drought in Malawi.” 2010. Web. 22 Aug 2019.

Vancouver:

Glad PA. Meteorological and hydrological conditions leading to severe regional drought in Malawi. [Internet] [Thesis]. University of Oslo; 2010. [cited 2019 Aug 22]. Available from: http://urn.nb.no/URN:NBN:no-26053 ; https://www.duo.uio.no/handle/10852/12663 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12663/1/PDF_of_Master_thesis%5B1%5D.pdf.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Glad PA. Meteorological and hydrological conditions leading to severe regional drought in Malawi. [Thesis]. University of Oslo; 2010. Available from: http://urn.nb.no/URN:NBN:no-26053 ; https://www.duo.uio.no/handle/10852/12663 ; Fulltext https://www.duo.uio.no/bitstream/handle/10852/12663/1/PDF_of_Master_thesis%5B1%5D.pdf

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.