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Developing a dynamical system model for an urban aquifer - Wadi systemAljuhani, Abdulkhaliq Malla January 2017 (has links)
Urban waste water production increases day by day and its safe treatment and disposal need efficient procedures. In many areas, such effluents are discharged to open water bodies such as lakes, rivers and sea coastal areas. Since there are no perennial streams in arid and semi-arid regions the disposal of treated outfalls is often to dry wadis. However developing an understanding of complex urban systems, where processes act at different space and time scales, is not easy. Dynamical systems approaches have been used for many years in complex feedback systems. So in this work the use of dynamical system modelling is investigated to see if this approach can help develop at least in semi-quantitative way an understanding good enough to aid managers of urban water systems where wadis are involved. The approach taken was to develop a flow and then a solute transport model for the urban system of Riyadh City - Wadi Hanifah. The softwares used was ‘Stella’, and a representation of two aquifers, two soil systems, the sewerage system, the water supply system, the non-urban catchments and the urban drainage system was set up and run using daily meteorological data for about 20 years. The model was compared with limited field data on water levels, flows, flooding, and water quality and modified until results were consistent with field data. Model was then investigated by looking at effects of changing a wide range of hydrogeological and other parameter values, including pipe leakage rates, rainfall, and water supply rate.
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Tracking Microplastics from Artificial Football Fields to Stormwater SystemsLi, Ran January 2019 (has links)
Microplastic pollution as a global environment problem in marine systems has substantially raised public concern in recent years. In 2016, the Swedish Environmental Protection Agency performed a study about potential sources and pathways of microplastics spreading to the marine environment. Microplastics from artificial turfs have been recognized as the second most important source of microplastic emission in Sweden. Between 1640 to 2460 tons per year of microplastics are estimated to be lost from artificial turfs. The lost microplastics are potentially transported to stormwater wells by runoff during rainfall events, eventually reaching marine environments. This study aims to track microplastics from artificial turfs to stormwater wells. Since the research of microplastic in stormwater has so far shown to be limited, field work and laboratory analysis have been developed in this study. Four artificial football fields located in Stockholm municipality were taken as sampling sites. First, pathways for microplastics from artificial turfs to stormwater were investigated. Second, the characteristics of microplastic granulates infill used in the football fields have been analyzed. Finally, stereo microscopy was used to visually identify microplastics in stormwater. The results showed that rainfall as a driving force of runoff process contributes to microplastics transport from artificial turfs to stormwater. During this transport process, a fraction of microplastics is captured by the soil. The size of microplastic granulates identified not only in stormwater but also in stormwater sediments is typically between 1 mm to 3 mm. Due to its limitations, stereo microscopy is quite a subjective method for identifying microplastics and thus not suitable for quantitative analysis, since microplastic particles are comparable in size to and visually difficult to differentiate from organic particles co-occurring in stormwater. In order to accurately quantify the amounts of microplastics transported to stormwater systems from artificial turfs, it is necessary to develop new methods for microplastics identification. This study presented an attempt in this direction, highlights its limitations, and discusses more suitable alternatives.
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A consideration of some of the factors influencing hillslope development in a sub-arctic environment.Wyrwool, Karl-Heinz. January 1971 (has links)
No description available.
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Microdebitage and the Archaeology of Rock Art: an experimental approachSusino, George James January 1999 (has links)
The search for a reliable and non-invasive technique for the dating of rock art has produced an array of different, localised, and limited techniques. This is one of them. Still in its experimental stage, the recognition of quartz microdebitage produced by the pecking of engravings is the aim of this project. This investigation aims to establish whether microdebitage from rock engravings can be distinguished from other sediments. Analysis of microdebitage from rock engraving experiments was used to determine the difference between experimental and naturally derived particles. This research discusses methodology, and applications for the recognition of quartz grain features, derived from experimental and natural material from Mutawintji National Park (Broken Hill, NSW, Australia) and the Sydney region (NSW Australia). A three-step process was devised for this research: What features occur on non-cultural quartz grains? What features occur on rock engraving quartz grains? Are they different? Can rock engraving quartz microdebitage be identified under natural conditions? Microdebitage from rock engravings was examined using optical and scanning electron microscopy to identify diagnostic attributes, with the objective of assessing the potential of microdebitage for spatial and temporal archaeological investigation. Characteristics of the quartz grains in the microdebitage were compared with quartz from differing environments. The observation of diagnostic features on quartz grains made it possible to discriminate between microdebitage from rock engravings and the natural soil background. This knowledge may be applied to excavated material from archaeological sites, for identifying episodes of rock engraving and other lithic activity in temporal relation to other evidence of cultural activity.
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Deglaciationsförloppet och Isdämda sjöar i Vindelälvens källområdeBlomdin, Robin January 2009 (has links)
<p>En detaljerad landformkartering av ett högfjällsområde i Vindelälvens källområde har utförts med syfte att öka kunskapen om inlandsisens dynamik och karaktär (iskantens reträtt, isens aktivitet och rörelseriktningar och isens basala temperatur) under deglaciationen i denna del av den Svenska fjällkedjan.</p><p>Undersökningsområdet antas ha varit beläget inom det, för inlandsisen, bottenfrusna kärnområde som karaktäriserade det senaste istidsmaximat (LGM). Trots avsaknaden av subglacial smältning under de kallbottnade subglaciala temperaturförhållandena fanns det tillgång på smältvatten. Spår efter forna issjöar och det glacifluviala landformsystemet är därför de enda data som finns för att rekonstruera isens reträttmönster där den varit kallbottnad eller där det är brist på andra landformer.</p><p>Den flygbildstolkning som genomfördes fokuserade på glaciolakustrina, glaciofluviala och subglaciala landformer. Rekonstruktionen av isreträttmönstet bygger på fördelningen av glacialmorfologin, de dämda issjöarna och den iskant som krävdes för att en dämning av dessa issjöar skulle uppstå. En teoretisk modell för beräkning av isprofilen användes för att öka detaljgraden i rekonstruktionen av isavsmältningen och som kontroll av den landformbaserade rekonstruktionen. Karterade landformer formade basen för issjörekonstruktionen som genomfördes i ett GIS. Som topografiskt underlag användes Lantmäteriets höjddatabas.</p><p>Iskantlägen rekonstruerade utifrån den teoretiska modellen visade god överensstämmelse med karterade landformer. Åtta issjöar kunde identifieras under arbetets gång. Två av dessa, Vindelälvens issjö och Båssjuosjávrrie – Gávásjávrries issjö, existerade med stor säkerhet och var ett dominerande inslag i landskapsbilden under deglaciationen. De dämdes i nordväst respektive västerut mellan blottade passpunkter i terrängen och den retirerande isen.</p><p>Dämningen av större smältvattenmassor visar att inlandsisen, i undersökningsområdet, var aktiv under hela deglaciationen och retirerade generellt mot sydost. Deglaciationsmodellen indikerade nordvästliga och västliga isrörelseriktningar, i ett tidigt skede av deglaciationen, och västliga i ett sent skede. Den sista isrörelseriktningen i undersökningsområdet var mot väst och härrörde förmodligen från den sista isdelaren vid lågfjället Kráhpiesvarrie. Den basala temperaturfördelningen i undersökningsområdet får dock ses som oklar pga. tvetydiga bevis.</p> / <p>A detailed landform mapping was carried out in the mountain region of the source area of River Vindelälven. The aim of this mapping study was to increase the current knowledge of the dynamics and character (the ice margin retreat, ice flow directions and the subglacial thermal organization) of the Fennoscandian Ice Sheet during the last deglaciation in this part of the Swedish mountain range.</p><p>The study area has been proposed to be situated within the cold based core area that characterized the last Ice age maxima (LGM). However, despite the lack of subglacial melting, glacial meltwater still exists. Traces after ancient glacial lakes and the glaciofluvial landform system are therefore the only data that exist when reconstructing the recession pattern of cold based ice sheets or when there is a general lack of glacial landforms.</p><p>The aerial photograph interpretation focused on glaciolacustrine, glaciofluvial and subglacial landforms. The reconstruction of the ice sheet recession pattern was thus based on the distribution of the glacial geomorphology, the dammed glacial lakes and the hypothetical damming ice sheet margin. A theoretical model for calculation of the ice surface slope profile was used to increase the detail level of the reconstruction and as a control of the landform based reconstruction. Mapped landforms formed the base for the glacial lake reconstruction that was carried out in a GIS. Lantmäteriets height database was used as a topographical base dataset.</p><p>Ice sheet margins reconstructed by the theoretical model showed good conformity with the mapped landforms. Eight glacial lakes where identified, two of these, Glacial lake Vindelälven and Glacial lake Båssjuosjávrrie – Gávásjávrries, existed with large safety and where dominant features in the landscape during the deglaciation. They where dammed in the northwest and west respectively between revealed saddle points in the terrain and the retreating ice sheet.</p><p>The damming of large glacial lakes shows that the ice sheet, in the study area, was active throughout the entire deglaciation. The ice sheet retreated generally towards the southeast. The presented deglaciation model indicated northwesterly and westerly ice flow directions in an early phase of the deglaciation, and westerly in a late phase. The last ice flow direction in the study area was towards west and it stemmed probably from the last ice divide situated above the low fell Kráhpiesvarrie. The subglacial thermal organization in the study area may be viewed as uncertain due to ambiguous evidence.</p>
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Geomorfologisk kartläggnng av Kungsbäckens avrinningsområdeSjö, Maria, Tähtikivi, Annelie January 2006 (has links)
<p>År 2015 ska alla avrinningsområden i EU-länderna vara fastställda. Anledningen till detta är att år 2000 trädde ett vattendirektiv i kraft. Syftet med direktivet är att skapa en helhetssyn för vattenresurserna i Europa och för att få en enhetlig och övergripande lagstiftning. I Sverige har SMHI redan bestämt vattendelare och avrinningsområden för ett stort antal områden i landet, men i och med direktivet har det blivit ett krav. En helhetssyn på vattenresurser tillsammans med kunskaper om geologi är en förutsättning för en hållbar utveckling och ett effektivt tillvaratagande av naturresurserna. Inom samhällsplaneringen spelar geologin en tämligen betydande roll. Vid exempelvis planering av nya bostadsområden är det av stor vikt att veta markens egenskaper.</p><p>Syftet med detta examensarbete var att fastställa Kungsbäckens avrinningsområde samt att göra en geomorfologisk undersökning av området. Arbetet syftade även till att redogöra för några fluvialmorfologiska förekomster kring del av Kungsbäcken - från utloppet vid Gavleån vid Stora Vall till viadukten vid Regementsvägen. Genom att utföra studien som en kombination av naturgeografi och GIT påvisas möjligheterna att utföra olika typer av analyser och beräkningar utifrån de naturresurser som finns i ett område och den moderna tekniken. Vidare kommer resultatet från denna studie att delges SMHI. De kan därmed få nytta av materialet när de, på uppdrag av Naturvårdsverket, skall utföra en kartläggning av Kungsbäckens avrinningsområde.</p><p>För att möjliggöra en geomorfologisk kartläggning av Kungsbäckens avrinningsområde och fastställa dess gränser studerades initialt tillgängligt material såsom tidigare studier, litteratur, terrängkarta, jord- och bergartskartor samt flygfotografier. Vid genomförandet av fastställningen av områdets gränser nyttjades bland annat SMHI:s tidigare gjorda gränser, en av oss gjord analog analys, utifrån tryckta terrängkartan 13H SV samt en flödesmodellering av en i studien gjord höjdmodell över området. Därefter gjordes fältstudier till tre stycken områden med osäkra områdesgränser, vilka framkom av ovan nämnda analyser. Med hjälp av flödesriktningsinstrument och okulär besiktning kunde gränserna då fastställas. Även fältstudier av geomorfologiskt intresse har utförts, såsom studie av ändmoräner och hällar.</p><p>Med hjälp av genomförda fältstudier, analyser, digitalisering och litteraturgranskning har gränserna för Kungsbäckens avrinningsområde bestämts samt beräknats till en area av 105,4 km2. Områdets geomorfologiska kartläggning har resulterat i en karta där de olika förekomsterna finns redovisade (se bilaga 1, karta i A3-format). Förutom detta finns olika begrepp och naturfenomen beskrivna i rapporten samt nyttan med denna typ av studie.</p> / <p>In year 2000, the EU Water Framework Directive was adopted and by 2015, all European watersheds have to be established. The purpose with the directive is to create an overall view over the water resources in Europe and to get a comprehensive legislation. SMHI in Sweden has already established a few watersheds around the country. An overall view of the water resources together with knowledge of the geology is a requirement to a sustainable development and an effective taking care of the nature resources. Within the physical planning, the geology knowledge is very important. For example, it is vital to know the quality of the ground when planning new building complexes.</p><p>The purpose with this bachelor thesis was to establish the watershed of Kungsbäcken and to do a geomorphologic survey of the area. The thesis also aimed to describe some of the fluvial morphologic presences, in a part of Kungsbäcken, i.e. from the outflow to Gavleån at Stora Vall, to the viaduct at Regementvägen.</p><p>By doing the study as a combination of physical geography and GIT, the possibilities to do different types of analyses and calculations, on the basis of the nature resources in an area and the modern technique are pointed out. Furthermore, the result from this study will be given to SMHI. The result may be of benefit to SMHI, when mapping the watershed of Kungsbäcken later on.</p><p>To make the geomorphologic survey of the watershed and to establish the boundaries of it, literature, earlier studies in the area, terrain- , rock, - soil maps and aerial photos were studied. Moreover, out of date-boundaries established by SMHI were used, together with an analogue analysis, based on the printed terrain map 13H SV. We also used a flow model, based on a digital elevation model over the area. The study also contained field trips. Three areas with uncertain boundaries were studied and with flow direction instruments and ocular examination, the boundaries were established. Field trips of geomorphologic interest were also made, like studies of recessional moraine and roch moutonnée.</p><p>By field trips, analyses, digitizing and literature perusal, the boundaries of the watershed of Kungsbäcken has been established and the area is 105.4 km2. The result of the geomorphologic survey of the area can be seen in a map (appendix 1). Apart from that, concepts and nature phenomena are also described in the report along with observations of the benefits of studies like this one.</p>
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Development of a Detailed Geomorphological Mapping System and GIS Geodatabase in SwedenGustavsson, Marcus January 2006 (has links)
<p>This thesis presents a method for detailed landscape presentation. The method incorporates both fieldwork-based comprehensive geomorphological description and digital data handling and thus contributes in filling the gap between traditional geomorphological mapping and modern geomorphological studies performed in Geographic Information Systems (GIS).</p><p>The main part of the thesis relates to development of a new detailed geomorphological mapping system, constructed to be easy to use and yet present a large amount of geomorphological information. The legend of the mapping system has successfully been applied to various types of landscapes, mapped at various scales between 1:5,000 and 1:50,000 without any modifications needed. The information presented in the map is based on simple descriptive criteria and thus the subjectivity is kept low, which enables a broad field of usage. In parallel with the mapping system a GIS-based geomorphological database has been developed. The structure and data presentation of the new mapping system allows for easy transformation of the data to form part of this database. The selected format of the GIS database is the ESRI ArcGIS<sup>®</sup>, Personal geodatabase.</p><p>In the development of the geomorphological mapping system four field areas have been mapped in central (Bonäs, Risa and Liden) and northern Sweden (Tarfala). In addition the new legend has been adapted to a field area situated in Vorarlberg, Austria (Upper Gamperdona valley).</p><p>In relation to the Tarfala field area an added issue of the project has been to give insights in the effects of physical and chemical weathering on various rock types to see if this can be detected in materials and landforms. The results from this study point at that resistance towards weathering vary among rocks even though they are of same rock type.</p>
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Mountain centered icefields in northern ScandinaviaFredin, Ola January 2004 (has links)
Mountain centered glaciers have played a major role throughout the last three million years in the Scandinavian mountains. The climatic extremes, like the present warm interglacial or cold glacial maxima, are very short-lived compared to the periods of intermediate climate conditions, characterized by the persistence of mountain based glaciers and ice fields of regional size. These have persisted in the Scandinavian mountains for about 65% of the Quaternary. Mountain based glaciers thus had a profound impact on large-scale geomorphology, which is manifested in large-scale glacial landforms such as fjords, glacial lakes and U-shaped valleys in and close to the mountain range. Through a mapping of glacial landforms in the northern Scandinavian mountain range, in particular a striking set of lateral moraines, this thesis offers new insights into Weichselian stages predating the last glacial maximum. The aerial photograph mapping and field evidence yield evidence that these lateral moraines were overridden by glacier ice subsequent to their formation. The lateral moraines were dated using terrestrial cosmogenic nuclide techniques. Although the terrestrial cosmogenic nuclide signature of the moraines is inconclusive, an early Weichselian age is tentatively suggested through correlations with other landforms and stratigraphical archives in the region. The abundance and coherent spatial pattern of the lateral moraines also allow a spatial reconstruction of this ice field. The ice field was controlled by topography and had nunataks protruding also where it was thickest close to the elevation axis of the Scandinavian mountain range. Outlet glaciers discharged into the Norwegian fjords and major valleys in Sweden. The process by which mountain based glaciers grow into an ice sheet is a matter of debate. In this thesis, a feedback mechanism between debris on the ice surface and ice sheet growth is presented. In essence, the growth of glaciers and ice sheets may be accelerated by an abundance of debris in their ablation areas. This may occur when the debris cover on the glacier surface inhibits ablation, effectively increasing the glaciers mass balance. It is thus possible that a dirty ablation area may cause the glacier to advance further than a clean glacier under similar conditions. An ice free period of significant length allows soil production through weathering, frost shattering, and slope processes. As glaciers advance through this assemblage of sediments, significant amounts of debris end up on the surface due to both mass wastage and subglacial entrainment. Evidence that this chain of events may occur, is given by large expanses of hummocky moraine (local name Veiki moraine) in the northern Swedish lowlands. Because the Veiki moraine has been correlated with the first Weichselian advance following the Eemian, it implies a heavily debris charged ice sheet emanating from the mountain range and terminating in a stagnant fashion in the lowlands.
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Development of a Detailed Geomorphological Mapping System and GIS Geodatabase in SwedenGustavsson, Marcus January 2006 (has links)
This thesis presents a method for detailed landscape presentation. The method incorporates both fieldwork-based comprehensive geomorphological description and digital data handling and thus contributes in filling the gap between traditional geomorphological mapping and modern geomorphological studies performed in Geographic Information Systems (GIS). The main part of the thesis relates to development of a new detailed geomorphological mapping system, constructed to be easy to use and yet present a large amount of geomorphological information. The legend of the mapping system has successfully been applied to various types of landscapes, mapped at various scales between 1:5,000 and 1:50,000 without any modifications needed. The information presented in the map is based on simple descriptive criteria and thus the subjectivity is kept low, which enables a broad field of usage. In parallel with the mapping system a GIS-based geomorphological database has been developed. The structure and data presentation of the new mapping system allows for easy transformation of the data to form part of this database. The selected format of the GIS database is the ESRI ArcGIS®, Personal geodatabase. In the development of the geomorphological mapping system four field areas have been mapped in central (Bonäs, Risa and Liden) and northern Sweden (Tarfala). In addition the new legend has been adapted to a field area situated in Vorarlberg, Austria (Upper Gamperdona valley). In relation to the Tarfala field area an added issue of the project has been to give insights in the effects of physical and chemical weathering on various rock types to see if this can be detected in materials and landforms. The results from this study point at that resistance towards weathering vary among rocks even though they are of same rock type.
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Palaeoglaciology of the northeastern Tibetan PlateauHeyman, Jakob January 2010 (has links)
This study concerns the palaeoglaciation of the northeastern Tibetan Plateau, with emphasis on the Bayan Har Shan (Shan = Mountain) in the headwaters of Huang He (Yellow River). To reconstruct past glacier development multiple techniques, including remote sensing, field investigations, cosmogenic exposure dating, and numerical modelling have been employed. Analysis of the large-scale geomorphology indicates that glacial erosion has been dominant in the elevated mountain areas on the low-relief plateau, whereas fluvial erosion outpaces glacial erosion along the plateau margin. Landform and sediment records yield evidence for multiple local glaciations, restricted to the highest mountain areas, and a maximum glaciation beyond the mountain front. Absence of data supporting the former presence of proposed ice sheets, plateau-wide or regional, tentatively indicates that no ice sheet glaciation occurred on the northeastern Tibetan Plateau. Cosmogenic exposure dating of boulders, surface pebbles, and sediment sections in central Bayan Har Shan indicates that its record of past glaciations predates the global Last Glacial Maximum (LGM). Based on a world-wide analysis, yielding that wide age disparity within apparent exposure age datasets is most likely caused by post-glacial shielding processes, the Bayan Har Shan exposure ages constrain four periods of glaciation with minimum ages of 40-65 ka, 60-100 ka, 95-165 ka, and undetermined oldest stage. Similar to Bayan Har Shan, the plateau-wide distribution of boulders with pre-LGM exposure ages close to present-day glaciers shows that its LGM glaciers were generally not much larger than today. The results of a high resolution glacier model applied to nine regions across the plateau indicates that temperature depressions of 2-4 K are enough to expand glaciers beyond their global LGM extent, implying that during periods of Northern Hemisphere glaciation the Tibetan Plateau was not much colder than today or became exceedingly dry. / At the time of doctoral defence the following publications were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.
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