| 1. |
- Hoffsten, Per-Ola
(författare)
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Galvån : Ett riksintresseområde för naturvården, X 105
- 1992
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- RiksintressetRikedom av forsar och strömmar i kombination med vattendragets storlek utgör en ovanlig och därför värdefull miljö.Området utgör även en värdefull biotop för sårbart djurliv bl. a utter, nedströmsvandrande insjööring.Översvämningsbetingade våtmarksmiljöer med rik flora, bl. a Kung Karls spira, intressant strandflora invid sidofåror, samt en unik svampflora invid biflödet Nybobäcken.
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| 2. |
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| 3. |
- Andersson, Agneta, et al.
(författare)
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Vertical transport of lipid in seawater
- 1993
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Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 98:1-2, s. 149-155
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Tidskriftsartikel (refereegranskat)abstract
- Lipids in seawater act as solvents and transporters of lipophilic organic pollutants. To investigate a possible transport route of lipophilic pollutants, the vertical flux of lipid was quantified during an annual cycle in the northern Baltic Sea. The lipid content in both sedimenting material and different size fractions of seawater was analyzed. During the year, 8 g lipid m-2 sedimented out from the photic zone to the benthic system. The sedimentation of lipid accounted for 300 to 400 % of the average standing stock of pelagic lipid and was concentrated in the spring bloom period (April-June) when 70 % of the total lipid sedimentation occurred. About 30 % of the produced pelagic lipid settled out from the system. In seawater the lipid maximum occurred at the end of the spring bloom, shortly after nutrient depletion, indicating a stress response in the algae. Since lipid sedimentation is concentrated in the spring bloom, removal of lipophilic organic pollutants may be important during this period.
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| 4. |
- Astrauskas, Andrius, et al.
(författare)
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Distribution and abundance of young pelagic fish : monitored by hydroacoustics in two coastal areas in the SW Bothnian Sea
- 1994
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The distribution of young pelagic fish in autumn was studied by hydroacoustic techniques in two coastal areas in the SW Bothnian Sea, one exposed to cooling water from a nuclear power plant and the second a reference area free from local disturbance. Generally, herring young-of-the-year dominated among pelagic fish and often constituted over 80% of the total numbers of fish counted. Young herring were concentrated to certain parts of the studied archipelagos, predominantly to the more shallow waters and to the outer parts of the small inlets commonly occurring in these coastal areas. When comparing the results of subsequent visits in the different study areas, it was evident that the estimated densities often varied markedly between days, although the distributionpatterns did not change. This was interpreted as an effect of migrations in and out of waters too shallow to be monitored by echosounder techniques. In September young herring evidently still depends upon an access to sheltered and very shallow habitats. Abundances of herring fry were higher in the cooling water exposed area compared to the reference, supporting earlier observations on positive temperature effects on fishrecruitment at this nuclear power plant.
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| 5. |
- Bengtsson, Lars, et al.
(författare)
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Cold climate hydrology in Sweden
- 1994
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Ingår i: Northern Hydrology International Perspectives. ; NHRI Science 3, s. 109-127
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Bokkapitel (refereegranskat)
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| 6. |
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| 7. |
- Berndtsson, Ronny, et al.
(författare)
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Some Eulerian and Lagrangian statistical properties of rainfall at small space-time scales
- 1994
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Ingår i: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 153:1-4, s. 339-355
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Tidskriftsartikel (refereegranskat)abstract
- Management of urban hydrological systems requires a knowledge of short-term and small-scale rainfall properties. Small catchment areas, dense building structures, a high degree of impermeable areas, and resulting rapid runoff, mean that the properties of individual rain cells are important considerations. Accordingly, this paper characterizes mainly spatial rainfall properties on a scale suitable for urban hydrology. Because of the usually dominant advective velocity component of individual rain cells the Eulerian view (observations of the moving rain cell by a fixed rain gage network) gives a distorted picture in the direction of movement of the actual rain cell. The extent of distortion depends on the magnitude of the advective velocity. The Lagrangian approach (moving along with the same speed and direction as the cell) gives different information regarding cell characteristics (e.g. size) compared with the Eulerian approach. It is shown that the Lagrangian cell size as indicated by the spatial correlation structure on average is twice the size of the Eulerian cell size. Thus, it is argued that the Lagrangian approach provides a more realistic picture of the rainfall structures compared with the Eulerian approach. The cell properties exhibit a temporal persistence of the spatial characteristics in the direction of movement. This persistence is, however, not strong and thus a forecasting procedure using advection only does not seem appropriate.
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| 8. |
- Berndtsson, Ronny
(författare)
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Transport and sedimentation of pollutants in a river reach : A chemical mass balance approach
- 1990
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Ingår i: Water Resources Research. - 0043-1397. ; 26:7, s. 1549-1558
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Tidskriftsartikel (refereegranskat)abstract
- The River Höje in the south of Sweden is a typical receiving water for urban and rural runoff. Mass balance calculations over a 17‐month period indicate that pollutants are retained in the sediments of the investigated 5‐km‐long reach of the stream (90 tons of biochemical oxygen demand (BOD7), 850 tons of chloride, 2.1 tons of copper, 3.2 tons of zinc, and 1.0 ton of lead). Other pollutants such as suspended solids and phosphorus appear to be both retained and washed‐out, depending on loading rates and local stream conditions. The retained pollutants represent a substantial part of the total mass transport through the stream (14–47%). Almost half of the transported zinc is retained within the stream sediment. Subsequently, the deposited pollutants represent a potential pollution source. Analyses of sediment samples verify that the upper sediments contain high concentrations of heavy metals.
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| 9. |
- Berndtsson, Ronny, et al.
(författare)
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Variability of soil water content along a transect in a desert area
- 1994
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Ingår i: Journal of Arid Environments. - : Elsevier BV. - 0140-1963. ; 27:2, s. 127-139
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Tidskriftsartikel (refereegranskat)abstract
- Spatial variation patterns of soil water content are investigated along a bare soil transect covering a crest-to-crest spacing (about 60 m) in a shifting sand dune area. Soil water content analyses from gravimetrical soil sampling and neutron probe observations are shown to give different information regarding variability patterns. Gravimetrical sampling displays a large effect of a small rainfall (4·5 mm) on spatial and temporal variability patterns. These effects are not clearly distinguishable from the neutron sond observations. Both gravimetrical and neutron sond observations display a small-scale variation that needs to be further investigated in order to be explained.
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| 10. |
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