The health of the Baltic Sea is negatively affected by hazardous substances such as metals and persistent organic pollutants (POPs), which include legacy pollutants that were banned decades ago, but still circulate in the ecosystem. Elevated levels of legacy pollutants, identified by HELCOM as key hazardous substances, have been found in accumulations of fibrous sediments, so-called fiberbanks and fiber-rich sediments, which derive from old pulp mills along the Swedish north coast. The fiberbanks are deposited in shallow water and bathymetrical models show evidence of their erosion, potentially caused by propeller wash, submarine landslides and gas ebullition. This thesis addresses the potential dispersal of key substances from three fiberbank sites located in a non-tidal Swedish estuary, in which metals and POPs are present in concentrations that may pose a risk for benthic organisms. Metals and POPs are partitioned to organic material and, as expected, show the highest partitioning coefficients (KD) in fiberbanks that have higher TOC levels compared to adjacent areas with fiber-rich sediments (natural clay sediments mixed up with fibers) or relatively unaffected postglacial clays. However, many analytes were found to be present in quantifiable concentrations in pore water, which indicates diffusion of substances from the solid phase to the aqueous phase. To assess the dispersive influence of an abrupt erosional event on dispersion, metals were measured in undisturbed bottom water and in bottom water disturbed by artificial re-suspension of fibrous sediments. The bioavailable, dissolved fraction of metals decreased in bottom water after re-suspension, probably due to the particle concentration effect. In contrast, the total concentrations of metals and number of quantifiable metals increased with particle concentration caused by re-suspension. At one station, the total concentration of chromium (Cr) was elevated to a level where it may lower the ecological status of the water body during periods of substantial erosion (e.g. spring floods or submarine landslides). Analyses of disturbed bottom water revealed, however, that minerogenic particles were preferentially re-suspended compared to organic. This suggests that physical erosion and re-suspension of fiberbank sediments might have a larger effect on dispersal of metals than on POPs. / TREASURE

Klimatförändringar har direkt påverkan på glaciärers tillväxt och avsmältning. Genom att studera glaciärers massbalans kan framtida riskbedömningar, för bland annat havsytans stigning, uppskattas. Skillnaden i glaciärens ackumulation och ablation ger den så kallade nettobalansen, som avslöjar om glaciären ökat eller minskat i massa under det gångna året. Storglaciären belägen i Tarfaladalen, öster om Kebnekaise, är en av världens mest välstuderade glaciärer. Här används den så kallade skandinaviska metoden för dokumentering av glaciärens massbalans. Metoden utgörs till stor del av manuella sonderingar i form av punktmätningar direkt på glaciärens yta. Då Storglaciären har upp mot 300 mätpunkter är inhämtningen av data både omfattande och tidskrävande. I detta kandidatarbete utfördes ett försök till optimering för den skandinaviska metoden på Storglaciären, med syftet att förhoppningsvis underlätta och effektivisera metoden. Punkter för mätdata avlägsnades för att undersöka om de resterande mätpunkterna gav ett godkänt värde för nettobalansen. För godkänt resultat av experimentet skall optimeringen ge ett representativt värde för storglaciärens nettobalans uppskattad med hela datamängden. Beräkningarna för nettobalansen är beroende av snöns densitet på glaciären, därav utfördes även densitetsmätningar i fält vid Tarfalas forskningsstation. Experimentet gav resultatet att metoden kan optimeras genom att var fjärde punkt för mätdata avlägsnades. Ytterligare studier kan dock utföras för att utforma mer specifika mönster för mätpunkter, som då skulle kunna ge ett ännu säkrare resultat för Storglaciärens nettobalans. / Climate changes has a direct impact on glaciers’ growth and melting. By studying the mass balance of glaciers, future risk assessments can be estimated by for example sea level rise. The difference between the glacier’s accumulation and ablation gives the net balance, which reveals if the glacier has increased or decreased in mass during the past year. Storglaciären, located in the Tarfala valley east of Kebnekaise, is one of the world's most studied glaciers. The Scandinavian method is used for documentations of the glacier’s mass balance. The method consists of manual probings at specific points on the glacier’s surface. Since Storglaciären has up to three hundred measurement points, the collection of the mass balance-data is both comprehensive and time consuming. For this bachelor project, an experiment was made to optimize the Scandinavian method at Storglaciären. The project was carried out with the aim of hopefully facilitating the method and to make it more efficient. Measurement points on the glacier were removed to investigate if the remaining points gave an approved value for the net balance. The requirement for the experiment to be approved is that the optimization shall provide a representative value for the net balance of Storglaciären, with all its measurement points included. The calculations for the net balance is dependent on the snow density on the glacier’s surface. Fieldwork at Tarfala research station was thereby carried out to collect data for the density on Storglaciären. The experiment gave the result that the Scandinavian method can be optimized. If every fourth measurement point on Storglaciären is removed, the glacier’s net balance is still representative. Further studies can be conducted to design specific patterns for removal of specific measurement points, which probably would provide even more accurate results for Storglaciären’s net balance.

The content of atmospheric dust in ice cores from Greenland varies with changes in climate, but the exact relationship is yet unknown. To determine this correlation, the source of the Greenland dust must be known. There are several hypotheses on the location of the source, but no current methods have been sufficient in determining the exact origin. This study explores the possibility of using elemental geochemical composition as an indicator for the dust origin. Major and trace element concentrations in loess and red clay samples from loess areas in Northern America, Europe, the Middle East, Central Asia and China were determined using handheld XRF. UCC-normalised values of major elements show similar trends for all areas, with depletion of Si, Al, Mg, K, Ti, Fe and Mn and enrichment of Ca and P in most samples. The elemental ratios Fe/Ti, Al2O3/SiO2, Al2O3/Ti, Fe/Al2O3, K2O/Al2O3, CaO/Al2O3, Rb/Sr and Zr/Rb display variations between areas, indicative of differences in weathering rates and grain sizes. The combined ratios Fe/Ti vs. K2O/Al2O3, Fe/Al2O3 or Al2O3/Ti can be used to differentiate loess from Canada, the US, central and eastern Europe, Israel and China. Central Asian loess however shows similar composition to Chinese loess. The results indicate that loess from different parts of the world have significant differences in elemental composition, which could potentially be used to differentiate between suggested sources of the Greenland dust. / Mängden stoft i isborrkärnor från Grönland varierar med förändringar i klimat, men det exakta sambandet är ännu okänt. För att kunna rekonstruera detta samband krävs att källan till stoftet är känd. Flera hypoteser finns idag kring denna källa, men inga hittills prövade metoder har kunnat urskilja ett definitivt ursprung. I detta arbete undersöks möjligheten att använda grundämnessammansättning som en indikator för stoftets ursprung. Koncentrationer av huvudelement och spårämnen i löss och röd lera från lössområden i Nordamerika, Europa, Mellanöstern, Centralasien och Kina bestämdes med handhållen XRF. UCC-normaliserade värden för huvudelement visar att områdena följer huvudsakligen liknande trender med reduktion av Si, Al, Mg, K, Ti, Fe och Mn och anrikning av Ca och P i de flesta prover. Grundämneskvoterna Fe/Ti, Al2O3/SiO2, Al2O3/Ti, Fe/Al2O3, K2O/Al2O3, CaO/Al2O3, Rb/Sr och Zr/Rb uppvisar tydlig variation mellan områden, indikativt för skillnader i vittring och kornstorlek. De kombinerade kvoterna Fe/Ti mot K2O/Al2O3, Fe/Al2O3 eller Al2O3/Ti kan användas för att särskilja löss från Kanada, USA, Central- och Östeuropa, Israel och Kina. Centralasiatisk löss uppvisar dock liknande sammansättning som kinesisk. Resultatet visar att löss från olika delar av världen har betydande skillnader i grundämnessammansättning, vilket skulle kunna användas som indikator för ursprunget till Grönlands stoft.

Glacial environments in the Arctic are a much-studied topic as well as a field of research with strong influences regarding the current and future global climate of our planet. This report is focused on the meteorological conditions on Nordenskiöldbreen glacier from 2009-2015 and how they correlate with each other, the glacier surface and the surrounding terrain. With data gathered from an automatic weather station located at the centre of the glacier, a range of meteorological parameters is examined; wind direction and velocity, snow depth, cloud cover, incoming and reflected shortwave radiation, temperature deficit, albedo and drifting snow. Seasonal differences were discovered, especially for wind direction and velocity where winds from the northeast occurred more frequently in the winter, indicating katabatic winds, whereas winds from the west and southwest were more pronounced in the summer. The calculated temperature deficit shows that katabatic winds blow down-glacier under stably stratified conditions and are shown to increase in strength with increasing temperature deficit (atmospheric temperature minus surface temperature). The mean albedo at Nordenskiöldbreen during this period is within the expected limits, 0.8 for snow and 0.3 for ice and the cloud cover was 0.58. Additionally, it could be observed that the occurrence of dry, drifting snow is present in the winter season as snow depth shows pronounced drops during high-wind events in winter. Overall, it is concluded that most of the examined parameters correlate and need each other to function and act as mechanisms within the cryosphere and as such it is crucial for scientists to understand their connected relationships when attempting to study global climate changes.

Varmare klimat är något som kontinuerligt påverkar glaciärer planeten över och har under det senaste århundrandet vidtagit en global ökning av negativa massbalanser. Denna trend kan bidra till variationer i havsnivån och orsaka problem med översvämningar över hela världen. Övervakning och observation av världens glaciärer är därför väldigt viktigt och genom att skapa modeller som tillåter insyn i glaciärernas respons till atmosfärisk fluktuation går det att åstadkomma en djupare förståelse för hur den globala uppvärmningen kommer att utvecklas. I detta projektet återskapas massbalansen för Brewster Glacier, Nya Zeeland, för perioden 2005 – 2015 genom tillämpning av graddagar. Modellen har försetts med data från ett nyligen genomfört nedskalningsprojekt som har producerat atmosfäriska data för perioden 1979 – 2015 vilket tillåter modellen att köras. Resultaten som presenteras kommer att bidra till större inblick i graddags-modellen om huruvida tillvägagångssättet att använda enkel temperatur- och nederbördsdata är tillförlitligt för att porträttera massbalansen för glaciärer. / Warmer climate is something that is continuously affecting glaciers across the planet and has during the last century gained a global increase in negative mass balances. This trend has contributed to sea-level rise and had other impacts on water resources. Monitoring and observing the worlds glaciers is therefore very important and by creating models that allows insight in the glacier response to atmospheric fluctuation, it is possible to obtain deeper knowledge on how the global warming will develop. In this project, the mass balance of Brewster Glacier, New Zealand, is reconstructed for the period 2005 – 2015 using a degree-day approach. The input for the model has been obtained from a recent downscaling project that has produced atmospheric data over the period 1979 – 2015 that allows the model to run at a daily temporal resolution. The results presented are going to contribute to a greater insight in the degree-day model as to whether the approach of using simple air temperature and precipitation data are reliable to portray the mass balance of glaciers.

In recent decades expanding land-use change has caused extensive deforestation of the tropical rainforestinducing large-scale transformation of the landscape patterns across the South American continent. Landscapechange is a modification process of the natural forest cover into fragments which generate various ecologicalimpacts. Habitat loss is identified to be a major threat to biodiversity, as it exposes species to the risk ofextinction. This study investigates 80 locations within tropical rainforest biomes to examine the landscape changewhich has occurred from 1993 – 2014. The intention is to identify the impacts of landscape fragmentation onhummingbird species diversity by spatial landscape analysis in GIS and regression modeling. The analysis foundthat there is no relationship between deforestation and reduction of hummingbird diversity. The results indicatethat hummingbird species are not particularly sensitive to landscape change as they have high resilience in regardto forest fragmentation. A potential threshold value of deforestation degree could be identified, up to whichhummingbird species richness increased, but locations subjected to over 40% fragmentation were estimated tohave lower hummingbird diversity. However, by using the spatial explicit biological data, the analysis indicatethat an extinction debt may exist in the landscape, and that future extinctions may be expected to occur in thefollowing decades as consequence of deforestation. Other factors may be as important determining variables forspecies richness: the spatial scale of the study, the habitat connectivity, hummingbird generalist tendencies.Conclusively, identification of the key factors of deforestation impacts on species diversity is essential for futureefficiency in conservation planning and sustainability of the tropical rainforest biodiversity.

To provide an increased breadth in the knowledge of tephra dispersal, this pilot study examines a peat core from Lakselv in Finnmark County in northern Norway. Peat samples are exposed to burning, HCl, density separation and polarized light microscopy. One sample from a depth of 37.5-40 cm was analysed using an electron microprobe analyser (EMPA). At least two tephra horizons were identified, one at a depth of 12.5-17.5 cm and one at 37.5-40 cm. The lower horizon shows a chemical composition similar to eruptives from Jan Mayen and São Miguel, Azores while the origin of the upper horizon is unknown as no geochemical analysis was performed for that depth.

Risken för översvämningar runt Mälaren idag är stor, vilket riskerar att drabba både städer och stora områden med jordbruksmark i Mälardalen. I samband med att Slussen i centrala Stockholm byggs om kommer regleringen av Mälaren att ändras. Den nya regleringen innebär bland annat att avtappningskapaciteten ökas, vilket syftar till att minska risken för översvämningar. Syftet med detta arbete har varit att redogöra för vilka konsekvenser olika stora översvämningar i Mälaren skulle kunna få på åkermark i Mälardalen samt att jämföra konsekvenserna vid den nuvarande och den nya regleringen. För att göra detta har kartor över översvämningar vid ett 10 000-årsflöde för de två regleringarna producerats med hjälp av geografiska informationssystem (GIS). Dessa har sedan använts för att beräkna arean översvämmad åkermark. Översvämningars varaktighet vid 100-, 1 000- och 10 000-årsflöden i sjön har även beräknats. Resultaten visar att betydligt större områden med åkermark skulle översvämmas vid ett 10 000-årsflöde med den nuvarande regleringen jämfört med den nya regleringen samt att varaktigheten hos en översvämning vid 100-, 1 000- och 10 000-årsflöden förkortas avsevärt med den nya regleringen. Eftersom långvariga översvämningar innebär större konsekvenser på åkermark än kortvariga översvämningar blir konsekvenserna på åkermark mindre med den nya regleringen jämfört med den nuvarande regleringen. / The risk of flooding around Lake Mälaren today is great and both cities and large areas of agricultural land in Mälardalen are at risk. When Slussen in central Stockholm is rebuilt, the regulation of Lake Mälaren will be altered. Changes in the new regulation include increase of the discharge capacity, which aims to reduce the risk of flooding. This report aims to describe which consequences floods in Lake Mälaren might have on arable land in Mälardalen and to compare the consequences of the current and the new regulation. To do this maps of the extent of the 10,000-year flood for the two regulations have been produced using geographic information systems (GIS). These maps have then been used to calculate the flooded area of arable land. Also the duration of the 100-, 1,000- and 10,000-year floods in the lake have been calculated. The results show that much larger areas of arable land would be flooded at a 10,000-year flood with the current regulation compared to the new regulation and that the duration of the 100-, 1,000- and 10,000-year floods will be considerably shorter with the new regulation. Because long-term flooding means greater impacts on arable land than short-term flooding, the impact on arable land will be less with the new regulation compared to the current regulation.

A Spatial Data Infrastructure (SDI) is required to make the spatial data be fully used and well shared by the society. In China, SDI’s has also been established progressively. A thorough understanding of the potentials and shortcomings about SDI in China has a positive significance to clearly identify the future direction and actions.In order to find out the potentials and shortcomings of SDI in China, the current situation of SDI and SDI in China have been assessed through literature review and interview. Then a Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis has been developed. Based on the current experiences of SDI development in China, the thesis concludes that China have a good potential to develop its SDI function. It also points out that there still are some weaknesses needed to be surmounted, such as: lacking advanced technology, data duplication, and lack of skilled workforce. There is a big room and capability to improve the development of Chinese SDI well in the future.

Agriculture is a climate sensitive sector whether it changes moderately and slowly or radicallyand rapidly. Many studies that focus on the vulnerability of agriculture, use climate scenariosand crop models to assess the potential impacts. This study seeks to identify (1) farmers‘awareness and perceptions of climate variability and change; (2) the types of adjustments theyhave made in their farming practices in response to these changes (farm responses, adaptivestrategies); and (3) other external factors (government policies, social, technological andeconomic conditions) that have significant impact on the farming activities.The results indicate that climate change and variability already have and will have mostlynegative impacts on agriculture. Prolonged dry spells and heat in the summer, less summerrain combined with higher temperatures, more heavy rainfall, more forest or grass fires andextreme weather: drought, flood, storms have been identified as highest climatic burdens toagriculture. An advanced start of the growing season is the the only truly positive change forthe majority of farmers. Apart from that several non-climatic factors were identified assignificant, among them political: high level of bureaucracy, lack of public trust in socialinstitutions, political instability; economical: incentives, for example tax exemption orreduction, access to subsidies and funds, economic growth and development, long-lastingeconomic recession; technological and infrastructural: access to advanced technologies,infrastructure and settlement development and poor road and railroad system; and social:population migration within Europa, ageing of population and population decrease. Thesesocio-economic factors play significant roles in overcoming the risks and building adaptivecapacity. This study shows that a variety of strategies and methods have been applied toreduce the vulnerability. Most often it is a farm level managerial decision, like, adjustedtiming of farm operations, changed crop variety and types, reduced number of livestock,improved technological base or increased income by off farm jobs.Finally we can conclude that even though individual farms have capacity to reducevulnerability, one must not underestimate the role of government and industry to decrease thedamages, take advantage of opportunities or cope with consequences. Farmer decision tomake changes in farming activities is rarely based on one risk alone.