Benthic diatoms are used in Sweden for monitoring water quality in run-ning water; the method is also frequently used in other countries in Europe. One of the problems of the diatom method is the need for sedimentation of the fresh sample, to be able to decant the over standing water and add alco-hol as a preservations solution. To my knowledge, no results have been published about how long the settling time must be to ensure that the ben-thic diatoms really have settled down to avoid a loss of the diatoms when decanting the over standing water. The aim of my investigation was to improve the Swedish method where the benthic diatoms are used for water quality monitoring. I wanted to find out the appropriate time necessary to wait until all diatoms have settled down before decanting the over standing water. First, fresh benthic diatom samples were taken in the river Fyrisån and the lake Mälaren on different days. After arriving in the laboratory, I waited three different times (30 min, 60 and 180 min) for the diatoms to settle.

Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.

For some time, there has been a general thought that churches built in the Early Middle Ages in Scandinavia, around the 12th century, directly replaced cult buildings or cult sites from the Late Iron Age. There are archaeologists who have criticized this and were instead skeptical that churches at all were built on places where a pre-Christian cult building existed. Several examples from Scandinavia contradict this and show a continuity of place and cult from the Late Iron Age to the Early Middle Ages. The aim of this thesis is through a spatial analysis, study Late Iron Age archaeological sites in the landscape around thirteen churches located around lake T?kern in the western part of ?sterg?tland, to see if there is a place and cult continuity from the Late Iron Age to the Early Middle Ages at the selected locations.

Construction of wetlands in the agricultural landscape may reduce nitrogen and phosphorus transfer to streams, thereby reducing the eutrophication of lakes and seas. The agriculturalstream Lillån, a tributary to stream Sagån, ends up in Lake Mälaren and is transporting large amounts of these plant nutrients. The aim of this study was to estimate how hypothetical wetlands of different size and location may reduce nitrogen and phosphorus load from stream Lillån. Estimated nutrient retention in several small wetlands was compared to retention in a single large wetland based on existing data from the agricultural stream and from a nearby smaller stream. Retention in the stream was suggested to decrease along with the nutrient concentration in the water.

The overall aim is to examine how the European Union Water Framework Directive has affected the local water management in the catchment Märstaån situated in the eastern part of the lake Mälaren river basin, Sweden. The first part of the study gives an historical overview of the area with focus on how the old agricultural landscape was handling the nutrient load from farming activities by means of different kinds of wetlands. By using the concept of the procedural landscape, introduced by Torsten Hägerstrand , together with historical maps with dates starting from the 17th century, the pre-modern landscape is analyzed.  The second part is an investigation, based on qualitative data, on how the different actors in the catchment area work together to secure the water quality for the Märstaån river. The analysis shows that the Märstaån catchment river systems are mostly unchanged in the rural areas.  The exception is the mainstream section of the Märstaån river running partly underground today and the Halmsjöbäcken river that is heavily affected by the Arlanda airport situated within the catchment area.

The location on the river delta of Klarälven, adjacent to lake Vänern, makes Karlstad one of the Swedish cities where a significant flood risk is present. The city has several major floods in its memory which has caused great material damage and economic losses, the latest of which occurred in the winter of year 2000/2001. The purpose of the study is to examine how the approach to flood risk has changed in the municipality of Karlstad since the 1950s, and how this change has affected the current situation regarding the city's vulnerability to flooding. To investigate this, a document analysis was conducted, where key documents in the media and from the municipality of Karlstad was studied. Furthermore, an interview study was conducted with respondents who currently are employed or previously have been employed in the municipality of Karlstad, who in various ways work with issues of flood risk. The result of the study shows that several changes have taken place since the 1950s in terms of the municipality's approach to flood risk, which for instance has led to preventative measures being taken to a greater extent than previously in the physical planning.

In Lake Vänern, Sweden, there is an endemic population of Atlantic salmon (Salmo salar L.) that lives its entire life in fresh water. The salmon is hindered from migrating to its natural spawning sites in the northern part of the River Klarälven by nine hydro-electric power plants. None of the hydro-electric power plants have fishways so that salmon migrating upstream or downstream may pass. In the current situation, the upward migrating salmon are caught in a fish trap at the most downstream located power plant in Forshaga. From there, the salmon are driven in a truck, past eight power plants and released a few kilometers upstream of the eighth power plant at Edsforsen.

This literature study concerned the use and function of the radioactive isotope carbon-14, as a dating method of organic material, within the scientific field of physical geography. In this report it is presented the need of atmospheric calibration curves and the development of these as a necessity to translate carbon-14 years to calibrated calendar years. A number of common age-depth models that is used to give an approximation of an accumulation sequence and its related dates over the actual time period in different natural archives is presented and discussed. Different problems that commonly occur when age-depth models are utilized as for instance reservoir effects, contaminations or other age deviations are addressed and analyzed. The software CLAM in presented and discussed and was also used to produce age-depth models.

AbstractConsequence analysis ?worst case scenario? at Mälarhamnar AB VästeråsDavid DotzskyMälarhamnar AB is a company that handle large amounts of oil, diesel, biofuel and petrol. That result in a lot of work to prevent accidents. The risks with modern technology is very small but it can?t be eliminated.

Predation is one of many factors that form the structure of the macroinvertebrate community in lakes, wetlands and watercourses. Earlier studies lack an examination concerning how fish- and waterfowl predation affect macroinvertebrates during shorter periods in the spring. I performed an exclosure study in the shallow eutrophic Lake Tåkern which is located in the western part of Östergötland County, Sweden. The experiment was performed during a three week period (1-21 April 2012) when the water temperature was low and the density of migrating diving ducks was high. The experimental cages used included three out of four different treatments; general predation (open cages), bird exclusion (net with mesh size 90*45mm) and no predation (net with mesh size 1*1mm).

This study focuses upon the new societal objects that are termed public privatepartnerships where the public sector forms strategic alliances with the private sectorand the civil society to manage the wicked issues of today. An exampel of suchcooperation is Vänerhamn AB where the municipalities around the lake of Vänernand the private shipping companies got togheter to handle an economic crisis of theshipping buisiness. The partnership Vänerhamn has developed from a problematicactivity to a healthy company and the aim of this thesis is to illuminate thisdevelopment through an historical institutional approach, focusing critical junctureto discover if the governance theory can be used to understand the partnershipspositive process. This will be done through research questions about the organisation of thepartnership, about the members interests with the partnership and about eventuallycoordination problems in the partnership. The questions derive from dimensions ingovernance theory, central for the activity of partnerships. Interviews with centralinformants where held and it was complemented through a document analyses inorder to search for indications of the dimensions and that is the methodologicalapproach of the study. The conclusion of this thesis is that the governance theory can be used tounderstand Vänerhamns postive development since the members interest with thepartnership to a begining was not at all conformed and that led to obviouscoordination problems.

The purpose of this master thesis is to describe and analyse the development of the library history in the municipality of Karlsborg. This is done with a comparison to the library development in Sweden as a whole and in particular to the cities of Lidköping and Halmstad. I have worked according to the following questions: 1. How did the libraries develop before the municipality took over? 2.

The purpose of this thesis has been to assess whether leaching from one particular Swedishlandfill site, Skörbytippen, is contributing to elevated levels of heavy metals in a ditch runningfrom the landfill site to the lake Mälaren in the communal region of Håbo kommun. Since theditch is stretching approximately five km downstream from the landfill site, in situ observationsand maps with known points of inflow was utilized to determine appropriate test points for thecollection of samples.Soil, water and sediment samples were collected and analyzed for content of organic material, pHand conductivity. Data on plant-available elements and total amounts of heavy metals wasacquired through ICP-analysis.The results show that the Skörby landfill is currently in the methane-forming anaerobedevelopment phase, which indicates that the concentration of free and complex-bound metals inthe leachate water should be low due to chemical binding with other landfill compounds. The pHof the sediment samples was generally one unit higher than the soil samples and some of themeasured data, such as pH and conductivity, show that an environmentally disturbing dischargeof some kind of strongly alkaline chemical(s) has been made from Benders? takpanneindustri inclose proximity to the landfill.

This is a study of the insect community associated to the wood-decaying fungus Inonotus radiatus found on Alnus glutinosa trees growing in riparian forests at the northern and southern shores of boreal lakes in the province Uppland. Little is known about this particular bracket fungus and its inhabitants. Insects were reared out at the laboratory from samples of fruiting bodies of the fungus taken at five lakes. During the fieldwork in 2009, data about several environmental variables was also taken. After the rearing period, these variables and their effects over the insects were analyzed.

AbstractHow do we remember? What do we remember? How does the memory change over time? These are the main questions in this essay.Five persons, who have lived or are still living in the old parish Rystad, situated seven kilometers from the town Linkoping south of Lake Roxen, have participated in interviews. They have been given the possibility to present their oral history which has been recorded and later transmitted to texture. The participants represent different social backgrounds and professions and they were born between the years 1920 ? 1936.