The Komie Creek map area was fully glaciated by the Laurentide Ice Sheet (LIS) during the Late Wisconsinan Fraser Glaciation. Ice flow during the glacial maximum was towards the southwest, as indicated by the orientation of streamlined landforms on the Etsho Plateau. At some time after the Fraser Glaciation maximum, the LIS divided into two lobes (upland and lowland). The subsequent landform assemblages, highlighted well in LiDAR imagery, provide evidence that the upland lobe retreated to the northeast and the lateral margin of the lowland lobe dropped to the southwest. Organic deposits are the dominant surficial material type in the Komie Creek map area. They have accumulated and been deposited on poorly drained clay and silt-rich morainal and glacio-lacustrine deposits. Morainal deposits are the next most common surficial material type in the area and dominate along the top of the Etsho Escarpment and in the northeast corner of the study area. Glaciofluvial deposits are rare. During ice retreat, an ice-marginal lake formed in the south-central part of the study area where the lowland lobe prevented drainage of meltwater out of the area. An aerially extensive landform, interpreted as an ice-contact glaciofluvial delta complex, was deposited into this dynamic glacial lake. The lake levels rose abruptly several times during delta deposition as a result of large west-flowing outburst floods in the Cabin Creek melt water channel, generated when a glacial lake breached its margins on or under the upland lobe. The delta is composed of several lobate landforms that sedimentologically are highly variable. This thesis presents a new, detailed 1:50,000-scale surficial geology map for the Komie Creek map area. This map was generated using aerial photographs, LiDAR DEMs, ground-based geophysics and field observations. This research also contributes to an increased understanding of the sedimentology and internal structure of ice-contact glaciofluvial deltas. / Graduate

A statistical comparison between the pre-investigations and the detailed site characterization while tunneling was performed in three areas of different rock quality in the Södermalm’s Tunnel. An overview of the site investigations performed prior to the construction works and the consequences in the tunneling method are also presented in this study. The statistical analyses in this study showed low correlation within the results obtained from the geotechnical investigations performed prior and while tunneling. The correlation diminishes as the rock mass quality decreases; however, in areas where the rock mass quality is high, the correlation is not as elevated as expected. The low association within those results may be due to diverse factors: the concentration of the pre-investigations in mostly three areas along the trace of the tunnel, and the extension of those results to the rest of the tunnel; the inappropriate utilization of the investigation techniques; and the lack of geotechnical data in the regional areas of Stockholm. The inaccurate geological characterization given by the pre-investigations leaded to great challenges in the most fractured and altered areas of the tunnel. A collapse occurred where the glaciofluvial sediments were in contact with the rock. The excavation had to be stopped and additional rock reinforcement had to be applied. Therefore, an increase of the expenses in terms of time and budget were the major consequences of the inaccurate predictions.

<p>In the recent decades, therehave been frequent conflicts between groundwater waterresources and environmentally hazardous activities. Newmethodologies for aiding decision-making in groundwater impactassessment and protection areneeded and in which issues ofincreased awareness, better understanding of the groundwaterresources processes, and validation of predictive mathematicalmodels are addressed.</p><p>A framework fordecision–aid, based on predictive simulations that a)predicts the environmental impacts b) provides the totaleconomical value c) visualises the impacts and the groundwaterproperties and d) describes the uncertainties in the results isproposed herein. The framework can be applied in environmentalimpact assessments, strategic environmental assessments andprotection and management of water resources. The results ofthe model are used as feedback for determining new scenarios,depending on the required uncertainties, and if the plannedactivity is sustainable, and/or fulfils the legislative andpolicy measures. This framework is applied to a particular casestudy, Nybroåsen, in the south-eastern part of Sweden,where the highway E22 is constructed through the importantglaciofluvial esker aquifer, passing the protection zone of thewater supply for the Kalmar municipality.</p><p>The impacts from the new highwayand the existing road have been predicted by two-dimensionalphysically based time-variant flow and solute groundwatermodelling. The results, breakthrough curves of contaminantconcentration in wells and maps of concentration distributions,as well as travel times, flow paths, and capture zones forwells determined by particle tracking have been presented.</p><p>The constructed model of theNybroåsen study area was calibrated by comparing observedand simulated groundwater levels for 15 observation wells forten years of measurements. The model has been evaluated bothgraphically and numerically and the calibration target wasfulfilled for 13 of the 15 observation wells. The model workincludes investigations of the catchment information, a waterbalance study, simulation of the groundwater recharge,consideration of the unsaturated zone by a numerical columnsimulation, and sensitivity analysis.</p><p>From the sensitivity analysis ofthe flow and transport parameters, it has been shown that theuncertainties are mainly due to the hydraulic conductivity.Comparison of the derived conductivity from the steady-stateautomatic calibration and the time-variant calibration showedthat there are major differences in the derived parameters,which illustrates the importance of a time dependentcalibration over both wet and dry periods and in more than onepoint in the area of interest of the model predictions.</p><p>In addition, a multi-criteriadecision analysis has been carried out for four roadalternatives (including the new highway E22) and the existingroad in the case study concerned. The multi-criteria decisionaid is applied as an illustration of how it can be used in thestudy area to identify a) interest groups of actors and theirconcerns b) ranking of alternative road scenarios according toactors’preferences and c) coalition groups of actors<i>i.e.</i>groups that have similar views with regard to theroad alternatives.</p><p><b>Keywords:</b>Physically-based groundwater modelling,contamination, flow and solute transport, glaciofluvialdeposits, Nybroåsen, Sweden, and multi-criteriadecision-aid.</p>

<p>Lake sediments are frequently used as archives of climate and environmental change. Minerogenic sediment variability in alpine lakes is often used to reconstruct past glacier and slope process activity. Alpine lake sediments can however have many different origins, which may induce errors in paleoenvironmental reconstructions. The aim of this project was to enhance the understanding of minerogenic lake sedimentation in alpine lakes and improve their use as environmental archives.</p><p>Catchment geomorphology and Holocene sediment sequences were analysed for five alpine lakes. Several minerogenic sediment sources were detected in catchments and sediment sequences. Slope-, fluvial-, periglacial-, nival- and aeolian sediment transportation processes contribute to create complex lake sediment patterns. Large variations in sedimentation rates were discovered within and between lakes, which has implications for sampling strategies and age-model constructions. Similar fine-grained minerogenic laminations were found in four of the investigated lakes, despite large differences in setting. The demonstrated similarity between glacial and non-glacial lakes may complicate interpretations of glaciolacustrine sediment signals.</p><p>The main conclusion is that lake sedimentation in alpine environments is highly dependent on several geomorphological factors. All lakes should therefore be viewed as unique and the geomorphology should be thoroughly investigated before environmental reconstructions are based on lake sediment proxies. This study has confirmed the multi-source origin of alpine lake sediment, which also opens possibilities of more multi-faceted paleoenvironmental studies. Different process-proxies could potentially be used to separate different climate signals, e.g. precipitation, temperature and wind, in lake sediments. Analysis of grain-size distribution, detailed mineralogy and magnetic mineralogy in combination with X-ray radiography are suggested methods for such reconstructions.</p>

Lake sediments are frequently used as archives of climate and environmental change. Minerogenic sediment variability in alpine lakes is often used to reconstruct past glacier and slope process activity. Alpine lake sediments can however have many different origins, which may induce errors in paleoenvironmental reconstructions. The aim of this project was to enhance the understanding of minerogenic lake sedimentation in alpine lakes and improve their use as environmental archives. Catchment geomorphology and Holocene sediment sequences were analysed for five alpine lakes. Several minerogenic sediment sources were detected in catchments and sediment sequences. Slope-, fluvial-, periglacial-, nival- and aeolian sediment transportation processes contribute to create complex lake sediment patterns. Large variations in sedimentation rates were discovered within and between lakes, which has implications for sampling strategies and age-model constructions. Similar fine-grained minerogenic laminations were found in four of the investigated lakes, despite large differences in setting. The demonstrated similarity between glacial and non-glacial lakes may complicate interpretations of glaciolacustrine sediment signals. The main conclusion is that lake sedimentation in alpine environments is highly dependent on several geomorphological factors. All lakes should therefore be viewed as unique and the geomorphology should be thoroughly investigated before environmental reconstructions are based on lake sediment proxies. This study has confirmed the multi-source origin of alpine lake sediment, which also opens possibilities of more multi-faceted paleoenvironmental studies. Different process-proxies could potentially be used to separate different climate signals, e.g. precipitation, temperature and wind, in lake sediments. Analysis of grain-size distribution, detailed mineralogy and magnetic mineralogy in combination with X-ray radiography are suggested methods for such reconstructions.

In the recent decades, therehave been frequent conflicts between groundwater waterresources and environmentally hazardous activities. Newmethodologies for aiding decision-making in groundwater impactassessment and protection areneeded and in which issues ofincreased awareness, better understanding of the groundwaterresources processes, and validation of predictive mathematicalmodels are addressed. A framework fordecision–aid, based on predictive simulations that a)predicts the environmental impacts b) provides the totaleconomical value c) visualises the impacts and the groundwaterproperties and d) describes the uncertainties in the results isproposed herein. The framework can be applied in environmentalimpact assessments, strategic environmental assessments andprotection and management of water resources. The results ofthe model are used as feedback for determining new scenarios,depending on the required uncertainties, and if the plannedactivity is sustainable, and/or fulfils the legislative andpolicy measures. This framework is applied to a particular casestudy, Nybroåsen, in the south-eastern part of Sweden,where the highway E22 is constructed through the importantglaciofluvial esker aquifer, passing the protection zone of thewater supply for the Kalmar municipality. The impacts from the new highwayand the existing road have been predicted by two-dimensionalphysically based time-variant flow and solute groundwatermodelling. The results, breakthrough curves of contaminantconcentration in wells and maps of concentration distributions,as well as travel times, flow paths, and capture zones forwells determined by particle tracking have been presented. The constructed model of theNybroåsen study area was calibrated by comparing observedand simulated groundwater levels for 15 observation wells forten years of measurements. The model has been evaluated bothgraphically and numerically and the calibration target wasfulfilled for 13 of the 15 observation wells. The model workincludes investigations of the catchment information, a waterbalance study, simulation of the groundwater recharge,consideration of the unsaturated zone by a numerical columnsimulation, and sensitivity analysis. From the sensitivity analysis ofthe flow and transport parameters, it has been shown that theuncertainties are mainly due to the hydraulic conductivity.Comparison of the derived conductivity from the steady-stateautomatic calibration and the time-variant calibration showedthat there are major differences in the derived parameters,which illustrates the importance of a time dependentcalibration over both wet and dry periods and in more than onepoint in the area of interest of the model predictions. In addition, a multi-criteriadecision analysis has been carried out for four roadalternatives (including the new highway E22) and the existingroad in the case study concerned. The multi-criteria decisionaid is applied as an illustration of how it can be used in thestudy area to identify a) interest groups of actors and theirconcerns b) ranking of alternative road scenarios according toactors’preferences and c) coalition groups of actorsi.e.groups that have similar views with regard to theroad alternatives. <b>Keywords:</b>Physically-based groundwater modelling,contamination, flow and solute transport, glaciofluvialdeposits, Nybroåsen, Sweden, and multi-criteriadecision-aid. / NR 20140805

Värmdö municipality, in the archipelago of Stockholm, has one of Sweden’s fastest growing populations and is a popular location for tourism and summer houses. This puts a lot of pressure on groundwater reservoirs and will likely be even more strained in the future as the climate continues to heat up due to anthropogenic activities. The aim of this study is to investigate the use of groundwater resources on the island of Ingarö, today and in a changing climate. The goal was also to identify the behaviour of the groundwater reservoir under different extraction rates. A model was constructed using MODFLOW, a software developed and maintained by the U.S. Geological Survey. The results show that for the present-day scenario with the current extraction rate there is a surplus of recharge leaving the reservoir. Moreover, three groundwater divides could be identified in the reservoir which can prove useful when examining the movement of contaminants. The result also indicated that an extraction rate of 105% of current extractions could be possible without any artificial infiltration. At an extraction rate of 110%, one well struggled with keeping up with demand for water. As the extraction rate increased further the results were deemed as inconclusive. For these scenarios, model domain required to be extended further east due to a constant head boundary condition acting as an infinite source of water in these cases. / Värmdö kommun har en av Sveriges snabbast växande befolkningar, därtill är kommunen en populär tillflyktsort under sommaren med många turister och andra som har sina sommarhus där. Många av dessa sommarhus har under de senaste 20 åren konverterats till permanentboenden och det är troligt att denna utveckling kommer fortsätta i framtiden. Detta medför att den redan begränsade tillgången på vatten ute i skärgården påverkas negativt och kommer spädas på ytterligare i samband med att klimatet blir allt varmare. Målet med denna uppsats var att kartlägga grundvattentillgångarna i Ingarö vattentäkt och hur dessa påverkas av klimatförändringarna samt under olika uttagsscenarion, där de olika uttagen kan spegla kraven på tillgång på vatten vid en ökande befolkning. En konceptuell modell skapades i Groundwater Modelling Systems (GMS) och i ArcGIS. Modellen löses sedan numeriskt med hjälp av grundvattenflödesekvationen i MODFLOW och lösningen importeras därefter tillbaka till GMS för analys. Den underliggande förutsättningen i modellen var att det nuvarande grundvattenuttaget och den naturliga återhämtningen av magasinet är lika stor. Den naturliga återhämtningen inom domänen, och de bidragande omkringliggande områdena, baserades på årsmedelvärden av nederbörd och evapotranspiration som hämtas från Sveriges Meteorologiska och Hydrologiska Institut (SMHI). De bidragande omkringliggande områdena identifierades genom att hitta vattendelare i landskapet med hjälp av en Digital Elevation Model (2x2 m). Jorddjupet i åsen beräknades med hjälp av Sveriges Geologiska Undersöknings (SGU) jorddjupsmodell som grund. I de områden där SGUs modell inte ansågs ge tillförlitliga jorddjup ersättes den med dels en jorddjupsmodell utvecklad på Kungliga Tekniska Högskolan (Simplified Regolith thickness Model) och dels med hjälp av kriging-interpolation över ett område med en högre densitet av kända jorddjupspunkter. Resultaten från det nutida scenariot med dagens uttag visade att det finns ett visst mått av överskott på vatten i åsen. Utöver detta så visade också resultatet att det finns tre grundvattendelare i vattenreserven vars placering kan visa sig nyttig för att förstå hur föroreningar kan sprida sig i åsen. Resultatet visade att uttag på 105 % av dagens uttag troligtvis är möjliga utan artificiellinfiltrering. Då uttaget ökades till 110 % började en brunn visa på svårigheter att leverera de volymer som förväntades. För uttag på 130 % och större visade sig resultatet vara missvisande då en stor mängd vatten strömmade in från den östra gränsen. Den östra gränsen av modellen bör därför förflyttas längre öster ut för att uppnå mer tillförlitliga resultat. Klart stod dock att den generella grundvattennivån lär sjunka i framtiden då evapotranspirationen förutspås öka mer än nederbörden.

<p>When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.</p><p>The purpose of this master’s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution. The purpose was also to determine the statistical properties of the hydraulic conductivity and to simulate the transport times and their variation from different locations in the aquifer to the pumping well.</p><p>The hydraulic conductivity was estimated from grain size distributions in soil samples that were taken at various locations within the test site. The analysis of the hydraulic conductivity showed a large variation and confirmed the hypothesis that the aquifer is heterogeneous. Using the statistics, a large number of stochastic conductivity fields were created and flow simulation was performed for each realization. From the simulation result, frequency distributions of the transport times were produced describing the probability for the transit time for a water particle between a certain location in the aquifer and the pumping well. A comparison with the tracer experiment shows higher simulated transport times implying the need for improved model calibration. The conclusion is that the method used in this project is suitable for glaciofluvial esker aquifers. When protection zones are delineated, stochastic modeling can be used to express the zone boundaries in statistical terms.</p> / <p>När skyddsområden för grundvattentäkter skapas är det viktigt att ha god kännedom om vattnets transporttider från olika delar i tillrinningsområdet till uttagsplatsen av grundvattnet. Metoderna för att bestämma dessa tider är ofta enkla och vanligen görs antagandet att områdets hydrauliska konduktivitet är relativt homogen. Många akviferer är dock kraftigt heterogena och de verkliga transporttiderna kan då skilja sig från de uppskattade. Som ett led i metodutvecklingen för bättre avgränsning av skyddsområden genomfördes ett spårämnesförsök i en isälvsavlagring i Järlåsa. Med utgångspunkt från försöket har en numerisk flödesmodell konstruerats över försöksområdet.</p><p>Syftet med examensarbetet var att tillämpa flödesmodellen i en akvifer där den hydrauliska konduktiviteten visar sådana variationer att den beskrivs bäst av en stokastisk fördelning. Vidare var syftet att bestämma den hydrauliska konduktivitetens statistiska egenskaper och att simulera transporttiderna och deras variation från olika punkter i akviferen till pumpbrunnen.</p><p>Den hydrauliska konduktiviteten uppskattades utifrån kornstorleksfördelningar i jordprover som togs på en mängd platser i försöksområdet. Analysen av den hydrauliska konduktiviteten visar stora variationer i området vilket bekräftar att akviferen är heterogen.</p><p>Utifrån konduktivitetens statistik genererades ett stort antal stokastiska konduktivitetsfält och transporttiderna beräknades för varje realisering. Resultatet från simuleringarna gav frekvensfördelningar för transporttiderna som beskriver sannolikheten för hur lång uppehållstid en vattenpartikel har i marken mellan en startpunkt och pumpbrunnen. Jämfört med spårämnesförsöket blev de simulerade transporttiderna något större vilket tyder på att flödesmodellen kräver en bättre kalibrering mot fältmätningar. Slutsatsen är att metodiken är lämplig för att studera vattnets transporttider i isälvsavlagringen och när ett skyddsområde skapas för den här typen av akvifer kan stokastisk modellering användas för att beskriva skyddszoner i form av statistiska termer.</p>

No description available.

When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site. The purpose of this master’s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution. The purpose was also to determine the statistical properties of the hydraulic conductivity and to simulate the transport times and their variation from different locations in the aquifer to the pumping well. The hydraulic conductivity was estimated from grain size distributions in soil samples that were taken at various locations within the test site. The analysis of the hydraulic conductivity showed a large variation and confirmed the hypothesis that the aquifer is heterogeneous. Using the statistics, a large number of stochastic conductivity fields were created and flow simulation was performed for each realization. From the simulation result, frequency distributions of the transport times were produced describing the probability for the transit time for a water particle between a certain location in the aquifer and the pumping well. A comparison with the tracer experiment shows higher simulated transport times implying the need for improved model calibration. The conclusion is that the method used in this project is suitable for glaciofluvial esker aquifers. When protection zones are delineated, stochastic modeling can be used to express the zone boundaries in statistical terms. / När skyddsområden för grundvattentäkter skapas är det viktigt att ha god kännedom om vattnets transporttider från olika delar i tillrinningsområdet till uttagsplatsen av grundvattnet. Metoderna för att bestämma dessa tider är ofta enkla och vanligen görs antagandet att områdets hydrauliska konduktivitet är relativt homogen. Många akviferer är dock kraftigt heterogena och de verkliga transporttiderna kan då skilja sig från de uppskattade. Som ett led i metodutvecklingen för bättre avgränsning av skyddsområden genomfördes ett spårämnesförsök i en isälvsavlagring i Järlåsa. Med utgångspunkt från försöket har en numerisk flödesmodell konstruerats över försöksområdet. Syftet med examensarbetet var att tillämpa flödesmodellen i en akvifer där den hydrauliska konduktiviteten visar sådana variationer att den beskrivs bäst av en stokastisk fördelning. Vidare var syftet att bestämma den hydrauliska konduktivitetens statistiska egenskaper och att simulera transporttiderna och deras variation från olika punkter i akviferen till pumpbrunnen. Den hydrauliska konduktiviteten uppskattades utifrån kornstorleksfördelningar i jordprover som togs på en mängd platser i försöksområdet. Analysen av den hydrauliska konduktiviteten visar stora variationer i området vilket bekräftar att akviferen är heterogen. Utifrån konduktivitetens statistik genererades ett stort antal stokastiska konduktivitetsfält och transporttiderna beräknades för varje realisering. Resultatet från simuleringarna gav frekvensfördelningar för transporttiderna som beskriver sannolikheten för hur lång uppehållstid en vattenpartikel har i marken mellan en startpunkt och pumpbrunnen. Jämfört med spårämnesförsöket blev de simulerade transporttiderna något större vilket tyder på att flödesmodellen kräver en bättre kalibrering mot fältmätningar. Slutsatsen är att metodiken är lämplig för att studera vattnets transporttider i isälvsavlagringen och när ett skyddsområde skapas för den här typen av akvifer kan stokastisk modellering användas för att beskriva skyddszoner i form av statistiska termer.