Headwater streams are affected by anthropogenic impacts at multiple scales. One aspect of human impact is Sediment transport associated to the abundance of stream structures as large woody debris and the composition of the riparian zone from forest to agricultural landscapes. Riparian buffer zones and stream structures like dead wood are considered as generally important structures for protection against an increasing amount of sediment particles in the water. Hence, in this study these structures were quantified in thirty different stream segments on land and in the water. To measure the transport of sediment Whitlock-Vibert boxes were used in three different types of landscapes; forest, transition and fields. The boxes were left in the stream segments for three months, the taken up and dried and weighed. The results showed that the transition-land in Frösvidalsån had the highest Sediment transport. The second highest transport of sediment was in Blackstaån at the fields.

För att förhindra övergödning används skyddszoner i stora delar av Sverige där jordbruk utförs. Det finns även andra faktorer som kan bidra till, eller förhindra, förluster av sediment via fluviala element i landskapet. Variationer i ett vattendrags omland påverkar hur den fluviala transporten av sediment ser ut. Syftet med den här studien är att kartlägga vilka faktorer som kan påverka hur transporten av upplöst sediment ser ut i Librobäckens nedre delar. Hur variationer i omgivningsmiljön skulle kunna skapa variationer i transporten av upplöst sediment.

The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.

Regulation of rivers by dams and reservoirs is a good example where anthropogenic impact could be considerable both in the local environment, but also has major implications upstream and downstream. This study was accomplished as a literature study of the river Nile, which is extremely important for water supply. The purpose of this study was to investigate the consequences of the construction of the Aswan High Dam, to obtain a consistent flow for water supply, irrigation and power generation in Egypt. Since Egypt has a very hot and dry climate large amounts of water in reservoir is lost to the Nubian aquifer system and by evaporation. The consequences from constructing the dam are considerable.

The amount of various phosphorus (P) fractions in the sediment and the relationship between the amount of P and sediment particle size were investigated in a constructed wetland southwest of Linköping. Furthermore, the possible correlation between clay content in the sediment and distance from the inlet was investigated. Sediment samples were collected along three transects from the inlet to the outlet, with six samples in each transect. In order to measure the soluble P, an NH4Cl extraction was done. This was also analysed for total soluble P after oxidation with peroxodisulphate.

Agricultural drainage ditches are links between fields, lakes and oceans, having the potential to transport e.g. sediment and nutrients. When in a good condition, drainage ditches can act as sinks for e.g. phosphorus and sediments and prevent eutrophication downstream. The aim of this study was to determine the condition of one agricultural drainage ditch and to come up with suggestions for appropriate measures. The aim was also to determine which of the ditch?s properties that were possible to evaluate visually, which processes they represented as well as which properties required complementary physical analysis. This in order to contribute to the work of developing a method for determining the status/condition of agricultural drainage ditches.

On ocean beds around the world sinking particles of residual biomass from animals and vegetation have, over time, accumulated into thick layers of sediment. For researchers these layers of sediment contain valuable information about the earth?s past climate, information that can be used to predict future climate change and to estimate natural vs. human causes of today?s global warming.The Institute of Geosciences at Stockholm University studies sediment cores that have been acquired with an apparatus called piston corer.

The metal mining history goes thousands of years back. The downside of the mining industry is the large amount of tailings created during the mining operations. Drainage and leaching of heavy metals from these tailings may cause major environmental problems including acid mine drainage and leaching of heavy metals. This study examines a pond located near an old mining site, where part of the old mining facility has been recently (1990) restored. The objective was to assess eventual metal contamination from historical mining and the recently performed restoration using a sediment core as a natural archive of historical metal inputs to the pond.

AbstractAt Saltvikens copperindustry, which is located in the municipality of Oskarshamn, copper was refined from sulphiteore some hundred years ago. The ore underwent several steps in the process before the final product was received. These steps all had an influence on the environment through discharge of heavy metals. The area where the copper industry was located is today considered to be of specific national interest due to its valuable nature and cultural values, as well as its value for recreational outdoor activities. Therefore, it is important to determine the present level of contamination and if any transport of contaminants have occurred, and to identify the risks that are associated with the site both at present and in a longer time perspective.Thirtynine soil samples and 16 sediment samples have been analyzed.

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.

Stormwater run-off from surfaces such as roads or rooftops is often polluted with heavy metals and nutrients. Many of these substances can cause great damage in biota if they end up in the recipient. In Sweden constructed wetlands and ponds for treatment of stormwater are frequently used, since research has shown that these treatment ponds are reducing stormwater pollution considerably to a low cost. The knowledge of these pollutant removal mechanisms and how follow-up and assessment of the ponds should be performed is still limited.To determine the pollutant removal efficiency of the stormwater ponds it is recommended that flow-weighted water samples are collected from both the inflow and the outflow of the pond. This method demands considerable resources of time and money for installations and analysis.

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.

Längs den svenska kusten verkar landhöjningen, en process där landet höjs efter den senaste istiden. Mest påtaglig är landhöjningen i Östersjön. Till följd av landhöjningen avsnörs grunda havsvikar från havet och bildar nya sjöar, så kallade flader, gloflader och glon. Målet med denna studie var att undersöka sediment från olika provtagningspunkter i en gloflad i Gårdskärsområdet i Lövstabukten (norra Uppland), för att se hur fördelningen av olika arter av kransalger varierat i glofladen under åren när miljön successivt förändrats. För att undersöka detta har oosporförekomst från kransalger i sediment studerats.

Fosfor (P) är ofta det begränsande ämnet i akvatiska system och kan i höga mängder bidra till övergödning i sjöar och hav. För att minska tillförseln av partikelbunden fosfor som läcker från jordbruksmark kan våtmarker anläggas i avrinningsområdet. För en effektiv avskiljning är det viktigt att partiklar sedimenterar i våtmarken och stannar i sedimentet. Studier har visat att vissa karpfiskar och märlkräftor genom bioturbation kan orsaka resuspension av partiklar, samt att effekten ökar med ökad täthet. Syftet med denna studie var att undersöka om även makroevertebraten Asellus aquaticus (sötvattensgråsugga) kan orsaka resuspension av partiklar.

För att kunna skapa intressanta och engagerande berättelser i spel behövs förståelse för hur spels unika egenskaper påverkar berättande. Ett spelnarrativa kan delas upp i det inbäddade narrativet, som består av till exempel texter och dialog, samt det emergenta narrativet, som uppstår ur spelets gameplay. När dessa två delar inte stämmer överens uppstår ludonarrativ dissonans. I detta arbete undersöks hur ludonarrativ dissonans påverkar narrativ transport, det vill säga inlevelse i en berättelse. Två versioner av ett berättelsedrivet spel skapades med olika mekanikerna för att uppnå låg respektive hög ludonarrativ dissonans.