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169 Uppsatser om Lake sediments - Sida 2 av 12

En studie av Växjö stadspark : med fokus på rekreation och sociala värden

Many people choose to live in urban environments. Since everyday life in many cities is characterized by a high pace it is important that good recreational areas, with the possibility of recovery, are available to the population.This paper is based on a case study of Växjö city park, which is the area surrounding the lake Växjösjön. The park and the lake are of great importance to the citizens. The lake Växjösjön has for a long time been affected by eutrophication, which has caused major problems as algal blooms and fish mortality. An extensive lake restoration was carried out in the 1990s in order to save the lake.

Teknikimplementering vid muddringsprojekt : Viktiga faktorer vid teknikval samt olika aktörers betydelse i processen

There are today large amounts of contaminated sediments in the Baltic Sea. These contaminants are the result of many years industrial activity where the contaminants have not been taken care of and just released out in the water. When ports want to dredge in their fairways and harbor areas the contaminated sediments need to be considered since they are a environmental risk. The development in this area has been slow and new techniques have just recently made its way into dredging operations in the Baltic Sea region. As a result of this there are no clear methods for implementing new techniques today.

The Lake

The purpose of ?The Lake? was to create an experience with music and visuals working with no budget.A personal purpose was that I wanted to explore new areas in design, like scenography, and combine them with my previous knowledge and skills. My method was to keep my hands busy at all times and use new materials. I also wanted to work with other creators and learn from their methods. Together with a musician I created the music and the concept for the project.

Effekten av kvävegödsling på gasproduktionen vintertid i boreala sjöar

To investigate effects of nitrogen on in-lake CO2 and CH4 production during winter, three pair of lakes was subject for a fertilizing experiment in which one lake in each pair was fertilized with nitric acid (HNO3) directly into the water column in the summer of 2012. The lakes in each pair are assumed to be morphologically, hydrologically and biologically similar, that is, the non-fertilized lakes are considered references. The pairs do differ in one major way by being progressively less humic, going from around 25 mg/l to 10 mg/l DOC. Sampling and analysis was carried out at the end of the frozen period in 2013. Results show a significantly higher concentration of both CO2 (p<0,001) and CH4 (?=0,1, p=0,053) between impact and reference sites in the two less humic pairs.

Tungmetallers påverkan på bottenfaunans artsammansättning i sjön Tisken

The purpose of this study was to investigate how elevated levels of heavy metals affect the faunal species composition, abundance and species-diversity. The bentic macroinvertebrate fauna in the highly polluted lake Tisken was compared with the bentic macroinvertebrate fauna in the unpolluted lake Varpan. Mine wastes account for most of the metal that is discharged into Tisken. The hypotheses was that the heavy metal pollutions in lake Tisken influenced the species composition, abundance and diversity of the macroinvertebrates. Twenty samples were taken in both sites.

Fisksamhället i Spexhultasjön, Nässjö

The lake Spexhultasjön is a moderate humic mesotrophic lake that is not acidified. The fish fauna was investigated by using a standard method for sampling freshwater fish with multi mesh gill nets. The fish fauna was diverse with perch, pike, tench, common whitefish, and roach. Perch and roach dominated. There were few pikes.

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.

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.

Löslighet och metylering av kvicksilver i en förorenad sjö (Ala-Lombolo) i Kiruna kommun :

Transformation of inorganic mercury (Hg) to methyl mercury (MeHg) is a biotic process that is proposed to be conducted primarily by sulphate reducing bacteria (SRB). The formation of MeHg is of great interest because it is the mercury species that biomagnifies to the greatest extent in the aquatic food webs; about 90 % of all Hg in fish is MeHg. Our understanding of factors involved in the production of MeHg is very important for making a reliable risk assessment. The purposes of this study were to investigate the different factors that control the solubility of Hg and the production of MeHg in a contaminated lake sediment. The lake Ala-Lombolo, Kiruna municipality, is well-known to be contaminated by mercury from different sources. Sediment cores were sampled at three different locations (N, SW and SE) in the lake and divided in three different layers; 0-5, 5-10 and 10-15 cm.

Konduktivitet i vattendrag som indikator på sura sulfatjordar

Increasing attention is being given to acid sulphate soils wherever they occur. The problems that leaching sulphate soils gives with significant lowerings of pH and mobilization of heavy metals influence large spectra of our society from fisheries to agriculture to construction. Mapping these soils is consequently of great importance and the methods of doing this is very much lacking in function and precision. This study was therefore carried out to investigate whether conductivity in running water can be used as a simple instrument to identify acid sulphate soils in the catchment. 31 coastal streams in the county of Västerbotten were analyzed for different catchment properties such as occurence of marine sediments and basic water chemistry including conductivity and sulphate.

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..

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.

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.

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