• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 248
  • 81
  • 40
  • 31
  • 26
  • 9
  • 6
  • 6
  • 3
  • 1
  • 1
  • 1
  • Tagged with
  • 578
  • 95
  • 74
  • 73
  • 71
  • 71
  • 69
  • 55
  • 49
  • 49
  • 46
  • 43
  • 43
  • 38
  • 37
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
431

Coupled flow and geomechanics modeling for fractured poroelastic reservoirs

Singh, Gurpreet, 1984- 16 February 2015 (has links)
Tight gas and shale oil play an important role in energy security and in meeting an increasing energy demand. Hydraulic fracturing is a widely used technology for recovering these resources. The design and evaluation of hydraulic fracture operation is critical for efficient production from tight gas and shale plays. The efficiency of fracturing jobs depends on the interaction between hydraulic (induced) and naturally occurring discrete fractures. In this work, a coupled reservoir-fracture flow model is described which accounts for varying reservoir geometries and complexities including non-planar fractures. Different flow models such as Darcy flow and Reynold's lubrication equation for fractures and reservoir, respectively are utilized to capture flow physics accurately. Furthermore, the geomechanics effects have been included by considering a multiphase Biot's model. An accurate modeling of solid deformations necessitates a better estimation of fluid pressure inside the fracture. The fractures and reservoir are modeled explicitly allowing accurate representation of contrasting physical descriptions associated with each of the two. The approach presented here is in contrast with existing averaging approaches such as dual and discrete-dual porosity models where the effects of fractures are averaged out. A fracture connected to an injection well shows significant width variations as compared to natural fractures where these changes are negligible. The capillary pressure contrast between the fracture and the reservoir is accounted for by utilizing different capillary pressure curves for the two features. Additionally, a quantitative assessment of hydraulic fracturing jobs relies upon accurate predictions of fracture growth during slick water injection for single and multistage fracturing scenarios. It is also important to consistently model the underlying physical processes from hydraulic fracturing to long-term production. A recently introduced thermodynamically consistent phase-field approach for pressurized fractures in porous medium is utilized which captures several characteristic features of crack propagation such as joining, branching and non-planar propagation in heterogeneous porous media. The phase-field approach captures both the fracture-width evolution and the fracture-length propagation. In this work, the phase-field fracture propagation model is briefly discussed followed by a technique for coupling this to a fractured poroelastic reservoir simulator. We also present a general compositional formulation using multipoint flux mixed finite element (MFMFE) method on general hexahedral grids with a future prospect of treating energized fractures. The mixed finite element framework allows for local mass conservation, accurate flux approximation and a more general treatment of boundary conditions. The multipoint flux inherent in MFMFE scheme allows the usage of a full permeability tensor. An accurate treatment of diffusive/dispersive fluxes owing to additional velocity degrees of freedom is also presented. The applications areas of interest include gas flooding, CO₂ sequestration, contaminant removal and groundwater remediation. / text
432

An experimental and simulation study of the effect of geochemical reactions on chemical flooding

Chandrasekar, Vikram, 1984- 17 February 2011 (has links)
The overall objective of this research was to gain an insight into the challenges encountered during chemical flooding under high hardness conditions. Different aspects of this problem were studied using a combination of laboratory experiments and simulation studies. Chemical Flooding is an important Enhanced Oil Recovery process. One of the major components of the operational expenses of any chemical flooding project, especially Alkali Surfactant Polymer (ASP) flooding is the cost of softening the injection brine to prevent the precipitation of the carbonates of the calcium and magnesium ions which are invariably present in the formation brine. Novel hardness tolerant alkalis like sodium metaborate have been shown to perform well with brines of high salinity and hardness, thereby eliminating the need to soften the injection brine. The first part of this research was aimed at designing an optimal chemical flooding formulation for a reservoir having hard formation brine. Sodium metaborate was used as the alkali in the formulation with the hard brine. Under the experimental conditions, sodium metaborate was found to be inadequate in preventing precipitation in the ASP slug. Factors affecting the ability of sodium metaborate to sequester divalent ions, including its potential limitations under the experimental conditions were studied. The second part of this research studied the factors affecting the ability of novel alkali and chelating agents like sodium metaborate and tetrasodium EDTA to sequester divalent ions. Recent studies have shown that both these chemicals showed good performance in sequestering divalent ions under high hardness conditions. A study of the geochemical species in solution under different conditions was done using the computer program PHREEQC. Sensitivity studies about the effect of the presence of different solution species on the performance of these alkalis were done. The third part of this research focused on field scale mechanistic simulation studies of geochemical scaling during ASP flooding. This is one of the major challenges faced by the oil and gas industry and has been found to occur when sodium carbonate is used as the alkali and the formation brine present in situ has a sufficiently high hardness content. The multicomponent and multiphase compositional chemical flooding simulator, UTCHEM was used to determine the quantity and composition of the scales formed in the reservoir as well as the injection and production wells. Reactions occurring between the injected fluids, in situ fluids and the reservoir rocks were taken into consideration for this study. Sensitivity studies of the effect of key reservoir and process parameters like the physical dispersion and the alkali concentration on the extent of scaling were also done as a part of this study. / text
433

Kartläggning av översvämnignshotade järnvägstunnlar med GIS : En fallstudie av Norralatunneln

Erik, Fridholm, Johan, Sjögren January 2014 (has links)
In August 2013 the Norrala tunnel just north of Söderhamn was flooded, which caused a train stuck in thetunnel. In the future the intensity and the amount of rainfall are expected to increase in this area, which canlead to an increased risk of flooding. The purpose of this study was to use GIS to investigate whether it is possible to identify which railroadtunnels that are exposed to flooding during heavy rainfall. In order to investigate this, a GIS analysis wasperformed on the Norrala tunnel. The data used for this study was the National Elevation Model. The result of the study contains maps representing the catchment area for the tunnels and wetness index forthe north and the middle rescue tunnel. The flood analysis shows that the rescue tunnel that was flooded in August 2013 has a catchment area of1,1km², which is 20 times as big as the catchment area for any of the other tunnel entrances. The studyshows that GIS is a great tool for flood mapping. With the chosen method in combination with theNational Elevation Model, it is possible to identify tunnels that are exposed to flooding. The field study that was performed shows that the Swedish property map has flaws concerning hydrology.More than 90% of the water that ended up in the tunnel came from the west side of the highway E4,through a passage for wildlife. After the tunnel, the water was initially directed through a manmade streamthat follows the route of the property map. Further down, the manmade stream disappears and the waterthen follows the topography to the protection barrier nearby the tunnel. In the study, no calculations were made about the amount of water that flooded to the tunnel during theflooding in August 2013. Investigations of the climate change indicate that the amount of rainfall willincrease in the area. Therefore a further investigation is recommended, where the goal should be to protectthe tunnel from flooding. The method that has been used is applicable at any type of infrastructure. The Swedish TransportAdministration is recommended to use this method to investigate infrastructure and for future planning. / I augusti år 2013 översvämmades Norralatunneln strax norr om Söderhamn, vilket orsakade att ett tåg fastnade i tunneln. I framtiden förväntas intensiteten och mängden nederbörd att öka i detta område, vilket kan leda till en ökad risk för översvämning. Syftet med examensarbetet var att med GIS undersöka om det går att identifiera vilka järnvägstunnlar som är översvämningshotade vid kraftig nederbörd. GIS-analyser utfördes på Norralatunneln, där den Nationella Höjdmodellen användes som indata till undersökningen. Resultatet av studien innehåller ett antal kartor som redovisar avrinningsområden för samtliga tunnelmynningar och fuktighetsindex för den norra och mellersta räddningstunneln. Översvämningsanalysen visar att den räddningstunnel som översvämmades i augusti år 2013 har ett avrinningsområde på 1,1 km², vilket är mer än 20 gånger så stort som avrinningsområdet för någon av de andra tunnelmynningarna. Studien visar att GIS är ett bra verktyg för översvämningskartering och med den valda metoden i kombination med den Nationella Höjdmodellen är det möjligt att identifiera översvämningshotade tunnlar. Den fältstudien som genomfördes visar på brister i fastighetskartan gällande vattendrag. Mer än 90 % av vattnet som rann in i tunneln kom från västsidan av E4:an genom en älgpassage. Därefter leddes vattnet ner mot räddningstunneln via en grävd bäck som till en början följer fastighetskartans sträckning. Den tydligt grävda bäcken försvinner dock och vattnet följer därefter topografin till skyddsdiket intill tunnelmynningen.  I arbetet gjordes inga beräkningar på hur mycket vatten som flödade ner till tunneln i samband med översvämningen. Undersökningar av framtida klimat visar på att nederbördsmängden i området kommer att öka. Därför rekommenderas en vidare studie där målet borde vara att ta fram ett lämpligt alternativ för att skydda tunneln från översvämning. Analyserna som har utförts är tillämpningsbara även på andra typer av infrastruktur, därför rekommenderas Trafikverket att använda sig av metoden vid projektering och undersökning av infrastruktur.
434

Methodik zur flächendifferenzierten Analyse und Bewertung von stofflichen Hochwasserrisiken

Sauer, Axel 25 March 2014 (has links) (PDF)
Die bisherigen Untersuchungen zu den Folgen extremer Hochwasserereignisse beschäftigten sich überwiegend mit den durch hohe Wasserstände und Fließgeschwindigkeiten verursachten direkten und tangiblen Schäden an Gebäuden und Infrastrukturen. Den durch schadstoffhaltiges Hochwasser hervorgerufenen direkten und indirekten sowie in der Regel intangiblen Konsequenzen für Mensch und Umwelt ist - insbesondere im Hinblick auf deren räumliche Verteilung - im Rahmen des Hochwasserrisikomanagements nur geringe Aufmerksamkeit gewidmet worden. Während Hochwasserereignissen können toxische Stoffe - wie beispielsweise Arsen, Blei, Cadmium oder Quecksilber sowie persistente organische Kontaminanten wie DDT oder HCH - aus belasteten Gewässer- und Ufersedimenten sowie Altstandorten und Altablagerungen freigesetzt werden. Diese Stoffe werden von der Hochwasserwelle aufgenommen, zum überwiegenden Teil partikulär gebunden transportiert und bei nachlassender Fließgeschwindigkeit und ablaufendem Hochwasser als Sedimente in den Überflutungsbereichen deponiert. In Abhängigkeit von der Nutzung der überschwemmten Gebiete sind nach einem Hochwasser unterschiedliche Rezeptoren den abgelagerten Sedimenten und darin enthaltenen Schadstoffen in der Regel langfristig ausgesetzt. Mögliche Rezeptoren sind zum Beispiel Menschen, Nutz- und Wildtiere, Futter- und Nahrungspflanzen sowie Böden mit ihren spezifischen Bodenfunktionen. Kern dieser Arbeit ist die Entwicklung einer räumlich differenzierten Methodik zur integrierten Analyse und Bewertung von stofflichen Hochwasserrisiken. Um deren Anwendbarkeit zu überprüfen, wird die entwickelte Methodik im Rahmen einer Fallstudie an Überflutungsbereichen entlang des Unterlaufes der Vereinigten Mulde zwischen Bitterfeld und Priorau erprobt, wobei der Fokus auf dem Rezeptor Mensch liegt. Die Methodik basiert auf der Integration von Verfahren der Hochwasserrisikoanalyse und der Schadstoffrisikoanalyse. Diese werden unter Verwendung eines angepassten Source-Pathway-Receptor-Consequence-Konzeptes kombiniert. Die Methodik besteht aus drei größeren Hauptelementen: (1.) der Gefahrenanalyse, (2.) der Expositionsanalyse und (3.) der Schadstoffrisikocharakterisierung und -bewertung. Die Gefahrenanalyse beschreibt die Freisetzung, den Transport und die Ablagerung der Stoffe in Abhängigkeit von der Hochwassercharakteristik, den Substanzeigenschaften sowie den Verteilungsprozessen nach der Ablagerung, beispielsweise dem Transfer vom Boden in die Pflanze. Ergebnisse der Gefahrenanalyse sind Karten der Schadstoffquellen in Form räumlich verteilter Stoffkonzentrationen in Umweltmedien wie Böden und Pflanzen. Die Expositionsanalyse stellt die Verbindung zwischen den Schadstoffquellen und den Rezeptoren her. Bindeglied sind Expositionspfade, beispielsweise die orale Aufnahme von kontaminiertem Boden oder der Verzehr von Pflanzen, die auf belasteten Böden angebaut werden. Teil der Expositionsanalyse ist eine so genannte Rezeptoranalyse, die - aus Landnutzungstypen abgeleitet - Vorkommen bestimmter Rezeptoren identifiziert und diese charakterisiert. Dabei bezieht die Rezeptoranalyse sowohl die räumliche Verteilung der Rezeptoren als auch deren Eigenschaften ein. Für den Rezeptor Mensch sind dies etwa physiologische Parameter wie Körpergewicht oder Atemrate sowie verhaltensbezogene Parameter wie Zeit-Aktivitätsbudgets oder Nahrungsaufnahmeraten. Daran anschließend wird mit der Expositionsanalyse im engeren Sinne die Exposition der Rezeptoren gegenüber bestimmten Stoffen quantifiziert, indem Transfer- und Aufnahmeraten von Expositionsmedien wie Boden, Nahrung oder Luft ermittelt und mit den darin enthaltenen Stoffkonzentrationen in Beziehung gesetzt werden. Ergebnis der Expositionsanalyse sind räumlich explizite Darstellungen der inneren Exposition, d.h. täglich aufgenommener resorbierter Schadstoffmengen. Darauf folgend werden im Zuge der Risikocharakterisierung die Effekte der Exposition mit Hilfe von Dosis-Wirkungsbeziehungen analysiert, die dann in Form von toxikologisch begründeten Referenzwerten als Basis für die finale stoffbezogene Risikobewertung dienen. Diese erfolgt durch Vergleich der inneren Exposition mit toxikologischen Referenzwerten in Form von tolerablen Aufnahmeraten. Die gesundheitlichen Risiken werden durch den Quotienten aus resorbierter Dosis und tolerabler Dosis beschrieben und als stoff- und pfadspezifischer Risikoindex flächenhaft dargestellt. Abschließend erfolgt eine Bewertung der Risiken mittels einer die Unsicherheiten der Referenzwerte berücksichtigenden Bewertungsfunktion. Die Methodik ist in Form eines GIS-basierten Rechenmodells umgesetzt und im Rahmen einer Fallstudie an der Vereinigten Mulde für verschiedene hydraulische Szenarien im Sinne simulierter Abflüsse verschiedener Jährlichkeiten - 100, 200 und 500 Jahre - erprobt worden. Als ausgewählte Ergebnisse liegen räumlich differenzierte Risikobewertungen für die Stoffe Arsen, Cadmium, Quecksilber und Blei unterschieden nach den Expositionsmedien Boden/Hausstaub, Luft sowie pflanzliche Nahrung vor. Exemplarisch seien hier ausgewählte Bewertungsergebnisse in Form des sogenannten Gefahrenwertes für ein HQ500-Szenario dargestellt: Durch die orale Aufnahme von Arsen über Boden/Hausstaub wird für den Rezeptor Kleinkinder räumlich begrenzt die Risikoschwelle überschritten, wobei die Handlungsschwelle nicht erreicht wird. Die Ergebnisse für Cadmium, Quecksilber und Blei liegen deutlich unter der Risikoschwelle. Ein ähnliches Bild zeigt sich für die Aufnahme über die Luft. Hier wird bei lebenslanger Exposition für Arsen die Risikoschwelle überschritten, für die anderen Stoffe werden Gefahrenwerte weit unter der Risikoschwelle ermittelt. Bezogen auf den Verzehr von Nahrungspflanzen aus Eigenanbau zeigen sich bei lebenslanger Exposition für Cadmium großräumig erhebliche Überschreitungen des Handlungsschwellenwertes. Für die anderen Stoffe finden sich nahezu flächendeckend Überschreitungen des Risikoschwellenwertes, die aber nicht an die Maßnahmenschwelle heranreichen. / Research on the consequences of flood events has so far focused on direct tangible damages to buildings and infrastructure caused by high water levels and flow velocities. In the context of flood risk management only little interest has been paid to direct and indirect as well as dominantly intangible consequences caused by flood pollutants to human and ecological receptors - especially taking their spatial distribution into account. During floods toxic substances such as trace elements (e.g. Arsenium, Cadmium, Mercury, Lead, Zinc) and persistent organic pollutants (e.g. HCHs, DDX) can be released from contaminated river bank sediments or former industrial sites. These substances are taken up by the flood water, get transported - mainly bound to fine particles - and get deposited as sediments in the floodplain in case of decreasing flow velocities. Depending on the land use in the floodplain, different receptors can be exposed to the sediments with the associated contaminants. Potential receptors are humans, livestock, wild animals, food and fodder plants as well as soils with their specific soil functions. The core of this thesis is the development of a spatially explicit methodology which enables the integrated analysis and evaluation of substance-based flood risks. To test the applicability, the developed methodology is applied within a case study dealing with floodplains along the lower reaches of the Vereinigte Mulde River situated between Bitterfeld and Priorau (Saxony-Anhalt, Germany). In this case study, the focus is on the receptor man or, more specifically, human health. The methodology is based on an integration of procedures from the fields of flood risk analysis and contaminant risk analysis. These procedures are integrated using an adopted Source-Pathway-Receptor-Consequence concept. The three main elements of the methodology are hazard analysis, exposure analysis and contaminant risk determination and evaluation. At first, the hazard analysis describes the release, transport and deposition of substances based on flood characteristics and substance properties as well as fate and transfer processes after sedimentation (e.g. soil-to-plant transfer). Results of the hazard analysis are maps of spatially distributed substance concentrations in environmental media such as soils and plants, i.e. the (secondary) contaminant sources. Within the exposure analysis the linkages between the contaminant sources and the receptors are described. Connecting elements are exposure pathways such as the ingestion of contaminated soil or the consumption of food produced on such soils. Part of the exposure analysis is a so-called receptor analysis which indicates and characterises potential human receptors that are derived from land-use types. The receptor analysis takes the receptors\' spatial distribution as well as certain properties into account. Taking the receptor human, these properties are physiological parameters such as body weight or respiration rate and behavioural parameters, e.g. activity budgets or food consumption patterns. Subsequently, with the exposure analysis in a narrower sense, the exposure of the receptors to a certain substance is quantified by calculating transfer and intake rates of exposure media such as soil, food or air taking into account the corresponding substance concentrations in these media. Results of the exposure analysis are spatially explicit representations of absorbed contaminant amounts for a certain receptor, i.e. daily resorbed exposure doses. In the course of the contaminant risk determination, the effects (consequences) of the receptors\' exposure are analysed by dose-response relationships, setting the basis for the final substance-based risk assessment in terms of toxicologically derived reference values. Health risks are expressed as ratio between calculated resorbed dose and tolerable resorbed dose and are presented as maps of substance- and pathway-specific risk indices. In a final step, an evaluation is carried out based on a method that takes the uncertainty of the toxicological reference values into account. The methodology has been implemented in a GIS-based calculation model and was applied within a case study to simulate floods with certain return periods (100, 200, and 500 years). Selected results are spatially differentiated risk evaluations for the substances arsenic, cadmium, mercury and lead distinguished based on the exposure media soil/house dust, air and home-grown vegetable food. Taking the 500-year flood-scenario and the risk evaluation value as an example, the following results have been derived: the oral intake of arsenic via soil/house dust leads to a spatially restricted exceedance of the risk level of the receptor infant, whereas the action level is not reached. The results of cadmium, mercury and lead are clearly below the risk level. A similiar pattern shows for the pulmonary intake via air. Based on lifetime exposure, the risk level for arsenic is exceeded, for all other substances the values are far below the risk level. Considering the intake of cadmium via consumption of home-grown vegetables, the action level is notably exceeded in large areas. The other substances show a nearly general exceedance of the risk level without reaching the action level.
435

Fuzzy logic based decision support system for mass evacuation of cities prone to coastal or river flood

Jia, Xiaojuan 08 April 2013 (has links) (PDF)
The increasing risk of river flooding or coastal submersion is already visible through recent events like the storm Xynthia and the floods in the Var department, which caused several dozens of deaths in France. These catastrophic events, even if their extent remains relatively limited, would have justified a preventive evacuation of high risk prone areas. However, the consequences for the population would be much more serious when large cities of hundreds of thousands of people will be partially or totally threatened by floods. This possibility is already an actual danger for large megacities like Bangkok and Alexandria, and also threatens French cities like Tours, Paris or Nice. Being more and more aware of this possibility, big coastal, estuarine and river cities in France, in Europe and in all continents are incited to prepare emergency and mass evacuation plans in order to prevent and cope with exceptional events. The elaboration of these plans is extremely complex and difficult due to technical, organizational, sociological and even political aspects. The great majority of cities in the world prone to large scale disasters do not already have this kind of plan at their disposal. Moreover, the existing state of the art shows that there are few operational tools to help territorial managers implement these plans in the phases of preparation and crisis management. Our work aims to contribute to the development of a support method for the evacuation decision taken in a crisis management context. This method is partly based on the information included in the provisional evacuation plans produced in the preparation phase. To reach this objective, we propose to adapt the tools of the fuzzy logic approach and apply them to a set of synthesized indicators. These indicators or decision criteria have been first selected from a method of evacuation planning previously developed by the research team Avenues-GSU. These criteria integrate classic data on the hazard level (overall forecast level and local flood water levels), the vulnerability of the territory and population and, which is more innovative, some information about the ability of the organization to evacuate and the security or the risk of the evacuation itself. The final result of this method, applied to the spatial dimension with the Matlab and ArcGIS software, is a map of the necessity to evacuate. This map shows the areas with the highest priority to be evacuated according to a fuzzy multicriteria analysis. It has been tested 5 at the pilot site of the city of Bordeaux located upstream in the Gironde estuary, and the theoretical results were compared with historical floods of 1981 and 1999. A hypothetic flood scenario was also studied taking into account the potential climate change impact and the consequences of a 1 meter sea level rise during the 21st century. This method and prototype tool should help policymakers to better understand a complex situation in pre-alert phase and assess the real need for urban zones evacuation on the basis of a limited but representative set of criteria. The maps of the necessity to evacuate represents an innovative proposal which extend and complement the existing official maps of flood forecasting (vigicrue) and its implications in terms of local impacts and crisis management anticipation.
436

Reciprocity : where art meets the community : action research in response to artistic encounters and relationships

Filardo, Giuseppe January 2009 (has links)
This practice-led research project examines some of the factors and issues facing artists working in the public domain who wish to engage with the community as audience. Using the methodology of action research, the three major creative projects in this study use art as a socio-political tool with the aim of providing an effective vehicle for broadening awareness, understanding forms of social protest and increasing tolerance for diversity. The three projects: Floodline November 7, 2004, Look in, Look out, and The Urban Terrorist Project, dealt with issues of marginalisation of communities, audiences and graffiti artists respectively. The artist/researcher is outlined as both creator and collaborator in the work. Processes included ephemeral elements, such as temporary installation and performance, as well as interactive elements that encouraged direct audience involvement as part of the work. In addition to the roles of creator and collaborator, both of which included audience as well as artist, the presence of an outside entity was evident. Whether local, legal authorities or prevailing attitudes, outside entities had an unavoidable impact on the processes and outcomes of the work. Each project elicited a range of responses from their respective audiences; however, the overarching concept of reciprocity was seen to be the crucial factor in conception, artistic methods and outcomes.
437

Resilient society, vulnerable people : a study of disaster response and recovery from floods in central Vietnam /

Beckman, Malin, January 2006 (has links) (PDF)
Diss. Uppsala : Sveriges lantbruksuniv., 2007.
438

A fortaleza de Mazagão-bases para uma proposta de recuperação e valorização

Matos, João Manuel Barros January 2001 (has links)
No description available.
439

Castelos da Ordem do Templo em Portugal 1120-1314

Oliveira, Nuno Villamariz January 2000 (has links)
No description available.
440

Utveckling av metod för översvämningskartering / Development of a flood extent mapping model

Olsson, Amanda January 2016 (has links)
The creation of reliable flood extent maps is becoming an increasingly important question as the  damage  caused by  natural  disasters  is  becoming  more  severe and the frequency of these events is increasing.  By limiting the uncertainty in flood modelling and simplifying the creation of flood extent maps, a more iterative process is made possible. This iterative process could potentially facilitate the development of more reliable emergency plans. The purpose of this report is to describe how water levels, simulated with a hydraulic model in an efficient way, can be processed in ArcGIS to produce flood extent maps. Focus has been placed on the inclusion of flooded areas occurring on the side of the river and the improvement of handling of tributaries. Inundated areas close to a flooded river can occur due to ground water interactions and increased surface runoff being trapped in low-lying points in the terrain. By analysing flood extent maps derived by various methods, a new model was developed in ArcGIS’s ModelBuilder. By viewing the entire river as a coherent unit the model produces flood extent maps with more reliable descriptions regarding connecting tributaries. This new model drastically decreases the need for manual adjustments and the creation of extra polygon shapefiles to constrain the interpolation area.  At the same time, it decreases the computation time due to the fact that it is a “cleaner” model. When applying the model on areas previously mapped using a tool developed at WSP (the KOG-tool) and MIKE 11’s built in tool for mapping of flood extent, it showed a high degree of accuracy. Concerning differences in water levels, the majority of raster values lay within a 0-1-millimetre range. These results imply a high credibility for the developed model. When evaluating the model against empirical flooding data, it showed satisfactory agreement, especially considering   the limited water level data available and the fact that the developed model does not take into consideration interaction with urban infrastructure or potential river blockages. / Efterfrågan av pålitliga översvämningskartor ökar med den ökade frekvensen av översvämningar med betydande negativ påverkan. Genom att minska osäkerheter i översvämningsmodellering och effektivisera genereringen av vattenutbredningskartor tillåts en mer iterativ process som medför mer pålitliga kartor. Syftet med denna rapport har varit att beskriva hur vattennivåer simulerade med hydrauliska modeller effektivt kan bearbetas i ArcGIS för att åstadkomma kartor över översvämningars vattenutbredning. Förbättrad hantering av översvämningsöar och anslutande biflöden har varit fokusområden. Genom att utvärdera och analysera vattenutbredningar genererade med olika verktyg har en modell, SÖK-modellen, utvecklats i ArcGIS:s ModelBuilder. Genom att hantera hela vattendraget som en sammanhängande enhet hanteras anslutande biflöden på ett sätt som leder till mer korrekt beskrivning av vattenutbredning i biflöden. Den framtagna modellen minskar drastiskt behovet av manuella justeringar och skapande av polygoner med syfte att begränsa interpolationsområden samtidigt som beräkningstiden minskas. Användning av modellen på områden karterade med ett av WSP utvecklat verktyg samt med MIKE 11s inbyggda modul för översvämningskartering visar på god överensstämmelse av interpolerade vattennivåer mellan de olika verktygen, de flesta skillnader är i storleksordningen 0-1 millimeter. Detta kombinerat med stora likheter i vattenutbredning mellan de utvärderade verktygen medför att den framtagna modellen anses lika pålitlig som övriga utvärderade verktyg. Vid utvärdering av modellen på en faktisk översvämning påvisades god överensstämmelse med observerad vattenutbredning, speciellt med hänsyn till den begränsade datamängd som funnits tillgänglig samt att den framtagna modellen inte tar hänsyn till interaktioner med urban infrastruktur eller eventuella blockader i vattendraget.

Page generated in 0.021 seconds