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195 Uppsatser om Boreal lake - Sida 2 av 13
Skårby : En kultplats med lång tradition
The ancient site of Skårby, situated about twenty kilometres south of Stockholm, includes one very large cairn enclosured by a stone wall with a small cairn attached to it. Cairns are originally thought of as graves, but resent research shows that they are more likely to have been religious objects. The constructions are seated on a small hill with a view over the lake Bornsjön which used to be a bay of the lake Mälaren. This place has been the object of worship throughout the whole Bronze Age. Over the years the manifestation of the worship changed, but the place for it stayed the same..
Höjning av vattennivån i Mälaren : Ett hot mot Stockholms centrala delar vid en framtida klimatförändring?
In today?s World is climate change an important and hot topic. Climate scenarios for Sweden show a warmer climate, especially during the autumn, winter and spring. The same climate scenarios also show that the precipitation will increase during this part of the year, however, during the summer the opposite is expected to occur. The purpose of this essay is to examine how future climate change will affect Stockholm especially the expected increase in precipitation, which may lead to a rising level of the Lake Mälaren. During 2000/2001 was Stockholm hit by a flood. This flood nearly resulted in major consequences and showed that there were significant risks for the city of Stockholm and increasing precipitation will result in even more water in the drainage systems of Lake Mälaren. The results presented here show that it is important to increase the drainage capacity of Lake Mälaren in order to reduce the risks of flooding in the central parts of Stockholm.
Storjuktan ? Rekonstruktion av ett sekels kvicksilverbelastning. : En undersökning av kvicksilverkoncentrationer i daterat bottensediment.
The aim of this study was to examine the current and historic mercury(Hg) load of the lake Storjuktan due to its recent exposure to a local potential source of Hg in form of the Sulphide mine Blaikengruvan(2006) and an earlier potential sources of Hg-load, the damming of the lake(1960s). Sediments were extracted using a HTH-sampler, freeze-dried, and analyzed for tot-Hg, LOI and activity of 210Pb and compared to samples extracted prior to the opening of the mine(2006). Constant initial concentration (CIC)-dating model was used for dating the samples. Low levels of Hg (100ng/g) were found throughout the lakes sediment. The highest levels of Hg(220ng/g) was detected at a depth of 4-5cm dating back to the mid 1970:s, suggesting that increased levels of atmospheric Hg rather than damming of the lake has caused the increase of Hg.
Dubbelkönighet hos mört : normalt eller miljöinducerat?
A number of chemical agents, and their degradation products, have been
recognized as having estrogenic activity on animals. On fish they interfere with
endogenous estrogen and in many cases mimic its activity, thus increase estrogenic
reponse, with elevated levels of vitellogenin. Hence they are called Endocrine
Disrupting Chemicals, EDCs. Vitellogenin levels is often used as a biomarker of
exposure to estrogenic pollutants. Wastewater from sewage treatment works
contains chemicals known as EDCs, and there are evidence of roach (Rutilus
rutilus) living in recipients of such wastewater having traits of both gender, i.e.
oocytes in male gonads (intersex) on histological examination.
This study was done on roach living in Lake Funbosjön Uppland, Sweden.
Naturvårdshänsyn i boreal bruksskog : En studie om avverkningar och avverkare i skogarna runt Saxdalen i södra Dalarna
As the past century?s technological development has progressed the Swedish boreal forests have transformed into dense, highly productive, homogenous and coniferous forests. The area around Saxdalen in Ludvika municipality has long been dominated forests which have been heavily worked since the 18th century. There are in Ludvika 119 000 hectares of productive forest land. Around 70 percent are owned by forest companies and 20 by private forest owners.
Recipientundersökning av Ensjön : Bedömning av sulfidmalmgruvan Enåsens eventuella påverkan på sjöns vattenkvalitet
Ensåsengruvan is a mine situated within Ljusdals municipality in central Sweden. Themine was in use from 1984 to 1991 and has since been undergoing a remediation program. Mine tailings from sulfide rich ore is a potential environmental hazard due to its tendency to cause acid waters and heavy metal leakage. Lake Ensjön is situated one kilometer from the mine area. Due to the hydrological conditions it was not expected to receive inflowing water from the mining area.
Sjöundersökning av Naalojärvi
LKAB is an international high tech mineral corporation and a world leading manufacturer of refined ironore products for steal manufacturing and other mineral products destined other industries. LKAB is an international corporation with companies world wide, with it?s main location in the north of Sweden, which is where the iron ore mines and the refining works are located. LKAB?s iron refining process in Vitåfors, Malmberget, is a source of great amounts of waste-rock.
Autumn water sources for understory vegetation and fungi in a boreal forest : an evaluation using stable isotopes
Understory vegetation and fungi are regarded as important ecological drivers of processes like productivity and nutrient cycling in boreal forests. Whilst those processes are linked to soil water content, relatively little is known about the sources of soil water for these forest
components. During early autumn in boreal forests, temperature falls and large events of rain are frequent which may influence soil water availability. To better understand the autumn plant-soil-fungi water relationships in this ecosystem, I used stable isotopes techniques in this
study to examine the water sources for ericaceous shrubs and fungi in a Scots pine forest following a large, early autumn rain event. I hypothesize that ericaceous shrubs of two functional groups (evergreen vs.
Effekter av kalavverkning på mindre boreala sjöars vattenkvalitet
Forestry is an important industry in Sweden, with clear-cut as the most commonly used method for harvesting. Here the long-term impact of clear-cut on lake water quality (dissolved organic carbon (DOC), nitrogen, phosphorus and pH) has been investigated, based on 23 lakes sampled during autumn. Data for additional 15 lakes sampled for the Swedish monitoring program were also used. Lakes were classified as 5, 25, 40 and 60 year based on data of the forest age in the catchment, gathered from the Swedish national forest inventory. Clear-cut lakes were classified as 5 years (>20% of the catchment clear-cut during the last 10 years).
Förändring av nitratläckage och växtproduktion från låglänt jordbruksmark vid en ny reglering av vattennivån i Mälaren
The water level of Lake Mälaren has been regulated since the 1940?s. A recentinvestigation suggests that the current regulation needs to be adjusted in order toprevent a decline in water level, salt water from infiltrating from Lake Saltsjön,and risk of floodings. In addition to these preventions, the new regulation couldpotentially effect the natural environment and agriculture practices in the lowlands that surround the lake. The new regulation proposal calls for an increase invariations in Mälaren?s water level during seasons, while the annual mean waterlevel will remain the same.
Inventering av kulturhistoriskt intressanta byggnader och miljöer, västra Möckelnstranden, Karlskoga
The report is a building evaluation of an area south of Karlskoga`s urban area on the west side of the lake Möckeln, known as the western Möckelnstranden. The evaluation is carried out on the behalf of Karlskoga municipality. The goal of the evaluation that is based on a mission statement is to create a basis for Karlskoga municipality for a detailed plan and exploitation of the area. The inventory contains suggestions on what should and should not be done with the environment and its buildings..
Geokemisk undersökning vid Rävlidmyrgruvan, Västerbottens län : provtagning, analys och förslag till åtgärder
The mining industry, in terms of ore excavation and metal production, is and has been
important to the Swedish economy. In connection with the ore excavation process, large
amounts of partly sulphidic waste are produced. When the metal sulphides are exposed to air and water they are eventually oxidised, which leads to the formation of acidic water with high concentrations of metal cations and sulphate ions, so called Acid Mine Drainage
(AMD). This water may reach the nearest surroundings and cause negative environmental
effects. By covering the waste with soil or water, the oxidation process can be minimised.
At the Rävlidmyran mine in the county of Västerbotten open pit mining took place between
1951 and 1991.
Metodikstudie av trollingfisket i Vänern : Jämförelse av fångstrapportering mellan intervjuer och enkäter gjorda på trollingfiskare samt vädrets påverkan på ansträngning
There are five endemic populations of migratory Atlantic salmon (Salmo salar, Salmonidae) and brown trout (Salmo trutta, Salmonidae) remaining in Lake Vänern, whereof two are salmon and three are trout. There is one population of each species in Klarälven, also one of each in Gullspångsälven and there is a population of trout still remaining in Tidan River. Since the beginning of the 20th century endemic populations of salmon and trout have either vanished or declined dramatically due to the construction of hydropower in the rivers around the lake, and still today the future of the remaining populations remains uncertain. To manage salmonid fishes effectively more knowledge of their ecology throughout their different life-stages is needed. A large part of the Lake Vänern salmonoids lives are spent in the lake, where a mayor mortality factor is recreational fishing, especially angling.
pH-sensitivity in boreal streams ? the influence of landscape characteristics
The goal of the society to increase the proportion of renewable energy has led to an increased demand of bioenergy e.g. forest biomass. However, there are concerns that removal of biomass will lead to decreased base cation concentrations in the soils and acidification of streams. In order to find in which types of landscape removal of branches and tops could have such negative effects, this study aims to analyse the relations between pH-sensitivity and landscape variables in the Bothnia Bay water district. GIS and digital geographical data were used to analyse the landscape in subcatchments.
Vattenkvalitén i Fredstorpsbäcken - dikad bäck på fastigheten Rämningstorp i Skara kommun :
The estate of Rämningstorp in the region of Västergötland in southern Sweden is administered by the holding trust company Skogssällskapet i Skövde. In 1999 measures were taken by Skogssällskapet to drain the stream Fredstorpsbäcken as a means to increase the forest productivity of the surrounding lands, which are situated on the estate of Rämningstorp. Almost immediately after the drainage, the streamwater turned turbid and a landowner downstream reported the issue to the county administrative board of the region.
The aim of this thesis was firstly to analyse the suspended matter that appeared during summer/autumn and secondly to explain why it came to be. Initial hypotheses for the explanation to the greyish turbid water were that it was either 1) a chemical/biochemical precipitate, or 2) an bacterial/algal blooming.