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Andersson, Jan-Olov
Publications (10 of 11) Show all publications
Temnerud, J., von Bromssen, C., Folster, J., Buffam, I., Andersson, J.-O., Nyberg, L. & Bishop, K. (2016). Map-based prediction of organic carbon in headwater streams improved by downstream observations from the river outlet. Biogeosciences, 13(2), 399-413
Open this publication in new window or tab >>Map-based prediction of organic carbon in headwater streams improved by downstream observations from the river outlet
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2016 (English)In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 13, no 2, p. 399-413Article in journal (Refereed) Published
Abstract [en]

In spite of the great abundance and ecological importance of headwater streams, managers are usually limited by a lack of information about water chemistry in these headwaters. In this study we test whether river outlet chemistry can be used as an additional source of information to improve the prediction of the chemistry of upstream headwaters (size < 2 km(2)), relative to models based on map information alone. We use the concentration of total organic carbon (TOC), an important stream ecosystem parameter, as the target for our study. Between 2000 and 2008, we carried out 17 synoptic surveys in 9 mesoscale catchments (size 32-235 km(2)). Over 900 water samples were collected in total, primarily from headwater streams but also including each catchment's river outlet during every survey. First we used partial least square regression (PLS) to model the distribution (median, interquartile range (IQR)) of headwater stream TOC for a given catchment, based on a large number of candidate variables including sub-catchment characteristics from GIS, and measured river chemistry at the catchment outlet. The best candidate variables from the PLS models were then used in hierarchical linear mixed models (MM) to model TOC in individual headwater streams. Three predictor variables were consistently selected for the MM calibration sets: (1) proportion of forested wetlands in the sub-catchment (positively correlated with headwater stream TOC), (2) proportion of lake surface cover in the sub-catchment (negatively correlated with headwater stream TOC), and (3) river outlet TOC (positively correlated with headwater stream TOC). Including river outlet TOC improved predictions, with 5-15% lower prediction errors than when using map information alone. Thus, data on water chemistry measured at river outlets offer information which can complement GIS-based modelling of headwater stream chemistry.

National Category
Earth and Related Environmental Sciences
Research subject
Risk and Environmental Studies
Identifiers
urn:nbn:se:kau:diva-41126 (URN)10.5194/bg-13-399-2016 (DOI)000369524500004 ()
Available from: 2016-03-23 Created: 2016-03-23 Last updated: 2020-01-10Bibliographically approved
Andersson, J.-O., Blumenthal, B. & Nyberg, L. (2013). Kartering av översvämningsrisker vid Vänern. Karlstad: Karlstads universitet
Open this publication in new window or tab >>Kartering av översvämningsrisker vid Vänern
2013 (Swedish)Report (Other academic)
Abstract [sv]

I denna studie genomfördes en översvämningskartering och -analys som utgick från fyra

extrema vattennivåer i Vänern. Baserat på höjddata från den Nya Nationella Höjdmodellen

(NNH) generades utbredningspolygoner med hjälp av GIS för de fyra översvämningsnivåerna.

Överlagringsanalyser gjordes sedan med kartskikt för väg, mark och byggnader

samt för vissa kommuner även befolkning för att urskilja vägsträckor, markområden,

byggnader och boende inom översvämningsutbredningen vid de fyra nivåerna.

Översvämningskartor togs fram i pdf-format och Google Earth-format. GIS-analysen har

genererat kvantitativa data för översvämmade vägsträckor, markytor antal byggnader etc.

Vidare har en objektsbaserad analys genomförts utifrån kartmaterial och kommunala data

över sårbara anläggningar och funktioner. Resultaten har sammanställts kommunvis och

för Vänerområdet i sin helhet i form av text, tabeller och diagram.

Det som drabbas först vid en översvämning i Vänern är dels objekt som utifrån sina

funktioner ligger vattennära t.ex. fritidsanläggningar, men även viktiga vägar som E18 och

E45. Järnvägsträckan Göteborg-Karlstad-Stockholm översvämmas redan vid 100-årsnivån.

Med stigande vattennivå drabbas allt fler objekt och samhällsviktiga funktioner. De städer

som påverkas mest är Karlstad, Kristinehamn, Mariestad, Lidköping och Vänersborg.

De direkta skadekostnaderna för en 100-årsnivå i Vänern har beräknats till 100-240 Mkr,

där en möjlig vindeffekt kan ge ytterligare upp till 120 Mkr i skadekostnader. För en

dimensionerande nivå skulle skadekostnaderna bli av en helt annan storleksordning och

uppgå till ca 9,8 miljarder kr. Vid denna nivå skulle stora indirekta skador uppstå som vi

inte har haft möjlighet att värdera ekonomiskt. De största kostnaderna kan kopplas till

översvämmade byggnader.

I en absolut jämförelse med Mälaren av kvantitativa data för översvämmade vägar,

markområden och antal byggnader är konsekvenserna vid Vänern något lägre.

Studien genomfördes på uppdrag av och i samarbete med

Vänerkommunerna i samverkan om

Vänerns reglering.

 

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2013. p. 158
Series
Centrum för klimat och säkerhet, Rapport ; 2013:1
Keywords
GIS, Översvämningsrisk, Sårbarhetskartering, Översvämningskador, Skadekostnader, Vänern, Risk
National Category
Geosciences, Multidisciplinary
Research subject
Risk and Environmental Studies
Identifiers
urn:nbn:se:kau:diva-33975 (URN)978-91-7063-527-4 (ISBN)
Available from: 2014-10-03 Created: 2014-10-03 Last updated: 2017-12-06Bibliographically approved
Swantesson, J. O. H. & Andersson, J.-O. (2011). Älvens betydelse för landskapet och människan. In: Ibsen, H., Svensson, E. & Nyberg, L. (Ed.), Klarälven: (pp. 13-26). Karlstad: Karlstad University Press
Open this publication in new window or tab >>Älvens betydelse för landskapet och människan
2011 (Swedish)In: Klarälven / [ed] Ibsen, H., Svensson, E. & Nyberg, L., Karlstad: Karlstad University Press, 2011, p. 13-26Chapter in book (Other academic)
Place, publisher, year, edition, pages
Karlstad: Karlstad University Press, 2011
National Category
Earth and Related Environmental Sciences
Research subject
Physical Geography
Identifiers
urn:nbn:se:kau:diva-30373 (URN)
Available from: 2013-11-28 Created: 2013-11-28 Last updated: 2020-05-04Bibliographically approved
Andersson, J.-O. (2009). A GIS-based landscape analysis of dissolved organic carbon in boreal headwater streams. (Doctoral dissertation). Karlstad: Karlstads universitet
Open this publication in new window or tab >>A GIS-based landscape analysis of dissolved organic carbon in boreal headwater streams
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In boreal catchments, stream water chemistry is influenced and controlled by several landscape factors. The influence of spatially distributed variables is in turn dependent on the hydrological scale. Headwater streams have larger variability of water chemistry, and thus together represent a large biodiversity, and therefore need to be monitored in official environmental assessments. One objective of this study was, using Geographical Information Systems (GIS), to analyse co-variation between landscape variables and water chemistry and to determine which of the landscape variables have a major influence on the concentration of dissolved organic carbon (DOC) in headwater streams. Another objective was to find a simple method for predicting sources of DOC, using official map data and publically available GIS applications.

Totally 85 headwater catchments (0.1-4 km2) in the county of Värmland, western south Sweden, were used in the study. Water chemistry was analysed for water sampled at low, medium and high flows, and landscape variables were extracted from official map data sources: topographic maps, a digital elevation model (DEM, 50 m grid), and vegetation data. Statistical analyses showed that topography (mean slope and mean topographic wetness index (TWI)) and wetland cover often correlated well with DOC in headwater catchments. Official map data could satisfactorily extract landscape variables (mean slope, mean TWI) that were useful in predicting stream water chemistry (DOC).

A high-resolution elevation model, which was generated by interpolation of photogrammetric data, was used to calculate and evaluate two different wetness indices and their ability to predict the occurrence of wetlands in six catchments of different sizes and topography. The SAGA (System for Automated Geoscientific Analyses) wetness index (SWI) gave substantially better results than the TWI. The effects of resolution of DEMs on calculations of the SWI were investigated using 5, 10, 25 and 50 m grids. The results showed that SWI values increased with increasing cell size. The near linear increment of mean values for resolutions 10-50 m suggests a independence of terrain type and catchment size, which supported previous findings that indicated that mean slope and mean wetness index calculated from coarse elevation models may be used for prediction of DOC in headwater streams.

 

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2009. p. 49
Series
Karlstad University Studies, ISSN 1403-8099 ; 2009:38
Keywords
boreal forests, wetlands, vegetation types, headwater streams, catchment hydrology, streamwater chemistry, DOC, GIS, terrain analysis, DEM, slope, wetness index, TWI
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-2925 (URN)978-91-7063-206-8 (ISBN)
Public defence
2009-10-02, Geijersalen, 12A138, Karlstads universitet, Karlstad, 13:15 (Swedish)
Opponent
Supervisors
Available from: 2009-09-24 Created: 2008-10-24 Last updated: 2011-10-04Bibliographically approved
Andersson, J.-O. & Nyberg, L. (2009). Using official map data on topography, wetlands and vegetation cover for prediction of stream water chemistry in boreal headwater catchments. Hydrology and Earth System Sciences, 13, 537-549
Open this publication in new window or tab >>Using official map data on topography, wetlands and vegetation cover for prediction of stream water chemistry in boreal headwater catchments
2009 (English)In: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 13, p. 537-549Article in journal (Refereed) Published
National Category
Biological Sciences
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-4673 (URN)10.5194/hess-13-537-2009 (DOI)
Available from: 2009-09-15 Created: 2009-09-15 Last updated: 2017-12-13Bibliographically approved
Andersson, J.-O. & Nyberg, L. (2008). Spatial variation of wetlands and flux of dissolved organic carbon in boreal headwater streams. Hydrological Processes (22), 1965-1975
Open this publication in new window or tab >>Spatial variation of wetlands and flux of dissolved organic carbon in boreal headwater streams
2008 (English)In: Hydrological Processes, ISSN 0885-6087, E-ISSN 1099-1085, no 22, p. 1965-1975Article in journal (Refereed) Published
Abstract [en]

In order to investigate the relation between water chemistry and functional landscape elements, spatial data sets of characteristics for 68 small (0·2–1·5 km2) boreal forest catchments in western central Sweden were analysed in a geographical information system (GIS). The geographic data used were extracted from official topographic maps. Water sampled four times at different flow situations was analysed chemically. This paper focuses on one phenomenon that has an important influence on headwater quality in boreal, coniferous forest streams: generation and export of dissolved organic carbon (DOC). It is known that wetland cover (bogs and fens) in the catchment is a major source of DOC. In this study, a comparison was made between a large number of headwater catchments with varying spatial locations and areas of wetlands. How this variation, together with a number of other spatial variables, influences the DOC flux in the streamwater was analysed by statistical methods. There were significant, but not strong, correlations between the total percentages of wetland area and DOC flux measured at a medium flow situation, but not at high flow. Neither were there any significant correlations between the percentage of wetland area connected to streams, nor the percentage of wetland area within a zone 50 m from the stream and the DOC flux. There were, however, correlations between catchment mean slope and the DOC flux in all but one flow situations. This study showed that, considering geographical data retrieved from official sources, the topography of a catchment better explains the variation in DOC flux than the percentage and locations of distinct wetland areas. This emphasizes the need for high-resolution elevation models accurate enough to reveal the sources of DOC found in headwater streams.

Keywords
boreal, landscape, catchment hydrology, headwater streams, streamwater quality, DOC, wetland, GIS
National Category
Biological Sciences
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-4672 (URN)10.1002/hyp.6779 (DOI)
Available from: 2009-09-14 Created: 2009-09-14 Last updated: 2017-12-13Bibliographically approved
Svensson, T., Andersson, J.-O., Blumenthal, B., Forsberg, J. & Hedelin, B. (2002). Projekt Byälven: Översvämningsrisker, förebyggande åtgärder och konsekvenser. Karlstad: Karlstads universitet, Nationellt centrum för älvskadeteknik
Open this publication in new window or tab >>Projekt Byälven: Översvämningsrisker, förebyggande åtgärder och konsekvenser
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2002 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, Nationellt centrum för älvskadeteknik, 2002
Series
Arbetsrapport
National Category
Civil Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-14852 (URN)
Available from: 2012-09-19 Created: 2012-09-19 Last updated: 2017-12-06Bibliographically approved
Blumenthal, B., Haas, J. & Andersson, J.-O. A GIS-based multivariate approach to identify flood damage affecting factors.
Open this publication in new window or tab >>A GIS-based multivariate approach to identify flood damage affecting factors
(English)Manuscript (preprint) (Other academic)
Abstract [en]

This paper investigates causal factors leading to pluvial flood damages, beside rainfall amount and intensity, in two Swedish cities. Observed flood damage data from a Swedish insurance database, collected under 13 years, and a set of spatial data, describing topography, demography, land cover and building type were analyzed through principal component analysis (PCA). The topographic wetness index (TWI) is the only investigated variable that indicates a significant relationship with to the number and amount of insurance damage. The Pearson correlation coefficient is 0.68 for the number of insurance damages and 0.63 for amount of insurance damages. With a linear regression model TWI explained 41% of the variance of the number of insurance flood damages and 34% of variance of amount of insurance flood damage.

Future studies on this topic should consider implementing TWI as a potential measure in urban flood risk analyses.

National Category
Other Earth and Related Environmental Sciences
Research subject
Risk and Environmental Studies
Identifiers
urn:nbn:se:kau:diva-70171 (URN)10.5194/nhess-2018-286 (DOI)
Funder
Länsförsäkringar AB
Note

This discussion paper is a preprint. It has been under review for the journal Natural Hazards and Earth System Sciences (NHESS). The manuscript was not accepted for further review after discussion.

Available from: 2018-11-19 Created: 2018-11-19 Last updated: 2019-04-29Bibliographically approved
Andersson, J.-O.DEM resolution effects on SAGA wetness index in boreal forested catchments.
Open this publication in new window or tab >>DEM resolution effects on SAGA wetness index in boreal forested catchments
(English)Manuscript (preprint) (Other academic)
National Category
Ecology
Research subject
Biology
Identifiers
urn:nbn:se:kau:diva-4676 (URN)
Available from: 2009-09-15 Created: 2009-09-15 Last updated: 2011-10-05Bibliographically approved
Nyberg, L., Andersson, J.-O., Mörth, C.-M. & Malmström, M.Influence of wetland restoration on hydrology and water chemistry in a Swedish boreal catchment.
Open this publication in new window or tab >>Influence of wetland restoration on hydrology and water chemistry in a Swedish boreal catchment
(English)Manuscript (preprint) (Other academic)
National Category
Biological Sciences
Identifiers
urn:nbn:se:kau:diva-4674 (URN)
Available from: 2009-09-15 Created: 2009-09-15 Last updated: 2017-12-06Bibliographically approved
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