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249 Uppsatser om Lake sediment - Sida 8 av 17

Jämförelse av platsspecifika föroreningsrisker i samband med muddringsaktiviteter

Stora volymer förorenade sediment kommer att behöva tas om hand under de kommande åren då bottensediment i svenska farleder, hamn- och kustområden under lång tid har konta?minerats av både tungmetaller och organiska föroreningar. I examensarbetet studeras fyra möjligheter för hantering av förorenade muddermassor. De tre traditionella metoderna är tippning till havs, utfyllnad i vik eller deponering på land. Stabilisering/solidifiering (s/s) är ytterligare ett alternativ som innebär att muddermassorna kan nyttiggöras i geokonstruktioner genom att massornas hållfasthet ökas.

Jordbruk och järnproduktion i Jämtland : Två näringar i södra Storsjöbygden under folkvandringstid

This essay is about two areas called Hackås and Myrviken, situated in the middle of Sweden around the lake Storsjön. In Hackås we can see traces after an early agrarian settlement, and in Myrviken we find Jämtlands largest concentration of ironmaking sites from around 400 AD. There are no clear evidence of the agrarian settlement in Myrviken, and only two ironmaking sites in Hackås. These two economies functioned at the same time, but were clearly separated. My purpose is to discuss if it was the farmers of Hackås who made iron in Myrviken, or if it was somebody else..

Karakterisering och klassificering av gotländska ytvatten enligt ramdirektivet för vatten

In this study the practical work with the EU Water Framework starts on the island of Gotland. 33 lakes and 32 streams have been characterized and classified regarding to their ecological status. The aim with the characterisation is to create a uniform discription of all waterbodies and a comparable estimation for the future. The aim with the classification is both to study the waterbodies ecological status and to gain knowledge of where the resources should be concentrated so that the ecological status in all waterbodies will be good in 2015.The characterisation has been done according to the EU Water Framework Directive, and the factors that have been applied are the mean depth and area of the lake. The length and size on the catchment area are the factors that have been used on streams.

Vegetationshistoria de senaste 5000 åren kring Fållnäs gård, Södermanland : med tyngdpunkt på antropogena aktiviteter

The manor Fållnäs gård is situated at the northern end of the bay Fållnäsviken, c. 12 km north-west of Nynäshamn, Sweden. A 300 cm long sediment core collected in the bay has been analyzed regarding pollen stratigraphy. AMS 14C dating of terrestrial macrofossils indicates that the sequence covers the last c. 5400 years.The aim has been to study vegetational changes, especially human impact, in the surroundings of Fållnäs gård.

A matter of trust : social interaction in a nature conservation issue in the Eastern slopes of Lake Vättern

Nature conservation issues are often complex and difficult to handle. Different actors andinterests are involved and it is generally agreed that constructive interaction is a crucialpart of dealing with these issues. According the theory which forms the basis of this thesis,conflict is defined as social interaction during which the actors trust in the interaction isdecreasing. Signs of conflict and diminished trust in the interaction are that these actorsmake attempts to change the situation and some of these attempts can lead to increasedconflict.The aim of this thesis is to describe the social interaction that takes place when peoplemove from conflict to dialogue. A qualitative case study of a nature conservation issue inÖstra Vätterbranterna, an area east of Lake Vättern, is presented.

Munksjökajen : Stadsplanering i Jönköping

Munksjökajen is an old industrial estate on the western shore of Munksjön in Jönköping. The purpose of this thesis is to develop Munksjökajen in accordance with the program for Jönköping?s future development ? Stadsbyggnadsvisionen ? drawn up by the city council.Munksjökajens relations to the surrounding areas have been investigated as well as the need for public transport and possibilities for commercial, municipal and private businesses to operate in the area.The final proposal has a relatively high degree of preserved industrial buildings. New buildings vary in shape and expression in order to create an interesting and diverse environment. The proximity to the lake adds character to the neighbourhood and the water is accentuated by the integration of it in the area..

Andraspråksutveckling i den mångkulturella förskolan

This thesis deals with two types of agrarian remains in relation to settlement remains; clearance cairns, low stone walls and house terraces in the area of Northeastern Uppland and the area north of Lake Mälaren, during the middle Iron Age. The aim whit this thesis is trying to get a better understanding of the relation between agrarian and settlement remains in Uppland. Three places have been chosen where these three elements are present and they are interpreted through Richard Whites concept of middle ground but also Landesque capital. The three elements have shown to be expressed in different ways in all three sites. It is possible to see two areas with different traditions, but also to see two areas that closely interact with each other, this opens up for a new discussion around agrarian remains in both areas.

Utvärdering av öppna dikens status och funktion : en förstudie i Västmanlands län

Evaluations of open Ditch status and function, with an assessment of suitability of a conversion to a two stage ditch as a low maintenance alternative. To illustrate Swedish drainage problems this work focused on two agricultural drainage associations assessed in detail with a new method called MADRAS (Minnesota Agricultural Ditch Reach Assessment for Stability). With the assessment of the MADRAS method estimates were made to conclude the ditches operating problems. This was made through measurements of sediment depths, mass bank failures etc. in order to quantify ditch problems and propose practical actions for improved ditch stability and water quality. The MADRAS surveys were conducted in two main ditches that drains 2900 hectares of land on the northern shores of Mälaren. In the study measurements of the ditch cross-sections were also conducted to compare actual profiles with the original map profiles. The evaluation showed that parts of the studied ditch sections were operatively poor; main reason was mass bank failure, undercut channel banks, sediment aggregations and narrowed ditches. The profile survey shows that a majority of the profiles 80 % has sediment accumulations there remains only 64 % of the original profile from the map.

Bottensubstratets inverkan på föryngring av Flodpärlmussla

The freshwater pearl mussel (Margaritifera margaritifera) is threatened throughout its range. There has been a substantial decline of the species and one major reason is habitat degradation. We investigated how the substrate composition of the bottom floor affects the regeneration of the mussel by analyzing data from the Västerbotten County Board?s inventory of the freshwater pearl mussel. The results implied that fine material such as fine sediment and sand might be detrimental to regeneration whereas gravel and boulders and in particular stone seem to be beneficial.

Tillväxtmönster och åldersstrukturer hos opåverkade bestånd av strömlevande Arktisk harr i Sibirien :

It is hard to find streaming waters where humans haven?t affected the fish populations or the running water it self. In many streams the fish populations are over harvested and this results in a lack of older and larger fish. This is also the situation for many populations of Grayling (Thymallus spp.). To be able to develop management plans and to perform actions that improve the situation for the grayling, it is therefore crucial to know what natural, by humans unaffected populations look like.

Storlommens (Gavia arctica) häckningsframgång relaterad till vattenkvalitet

This work investigates the breeding success of the Black-throated Diver, Gavia arctica, related to the water quality in three lakes located in the Vallentuna area, north of Stockholm, Sweden.For more than 30 years, I have studied the bird life around these three and other nearby lakes, and noticed that the Black-throated Diver breeds in some lakes, but not in others.The results confirm that the deep and clear lakes Tärnan and Stora Harsjön have good water quality regarding pH, alkalinity, aluminium and Secchi disk values. As expected, the Black-throated Diver shows breeding success in those two lakes, but does not breed in the shallow and eutrophic lake Mysslingen. .

Kvicksilversituationen i Stockholms skärgård

Kvicksilverutsläppen har på senare år minskat i omfattning men utsläpp sker fortfarande och det finns ett stort lager i naturen. Oorganiskt kvicksilver är relativt ofarligt för levande organismer, men i akvatiska miljöer kan sulfatreducerande bakterier under syrefria förhållanden omvandla oorganiskt kvicksilver till den betydligt mer skadliga formen metylkvicksilver, meHg, som även är mer biotillgängligt än oorganiskt kvicksilver. Kvicksilver biomagnifieras uppåt i trofinivåerna, från att vara lägst halter i plankton och bottenfauna till att vara högst halter i rovfiskar. Kvicksilver ackumuleras även i fiskars muskelvävnad vilket innebär att yngre fiskar har lägre Hg-halter än gamla och stora individer. På grund av detta finns kostråd framtagna av Livsmedelsverket.

Igensättning av långsamfilter i Östby vattenverk i Kramfors : studie av påverkande faktorer

Östby waterworks in the community of Kramfors has since 2003 had problems of fast clogging of the slow sand filters. As the clogging appears more often, they must be cleaned more frequently which has made the drinking water preparation difficult. Wintertime it has sometimes been impossible to clean the filters which has led to their closing and this has influenced the water quality negatively.The waterworks is a surface waterworks which takes its raw water from the lake Sjöbysjön. The water is flocculated and filtered in a contact filter with the flocculent EKOFLOCK 91. Thereafter it is alkalinized before it reaches the outdoors placed slow sand filters.

Vattenkvalitetsmätningar och sedimentprovtagningar i Luleås innerfjärdar under vinterförhållanden

Den senaste stora nedisningen orsakar fortfarande problem i landet. Ett av de mest påtagliga är den landhöjning som uppstod när trycket av den tjocka isen försvann. Denna landhöjning är orsaken till att Luleås innerfjärdar håller på att grundas ut och försvinna. Problemen kring innerfjärdarnas tillstånd har varit kända sedan början av nittiotalet och vattenkvalitetsmätningar har pågått sedan dess. Denna undersökning är den enda som ägt rum under vinterförhållanden och syftar till att ge en mer komplett bild av tillståndet i innerfjärdarna.

Uttryck i sten : En studie av röjningsrösen, stensträngar och husgrundsterrasser under mellersta järnålder i Uppland

This thesis deals with two types of agrarian remains in relation to settlement remains; clearance cairns, low stone walls and house terraces in the area of Northeastern Uppland and the area north of Lake Mälaren, during the middle Iron Age. The aim whit this thesis is trying to get a better understanding of the relation between agrarian and settlement remains in Uppland. Three places have been chosen where these three elements are present and they are interpreted through Richard Whites concept of middle ground but also Landesque capital. The three elements have shown to be expressed in different ways in all three sites. It is possible to see two areas with different traditions, but also to see two areas that closely interact with each other, this opens up for a new discussion around agrarian remains in both areas.

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