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  • 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.
171

Digitale Geländemodelle im Hochwasserschutz: Detektion, Extraktion und Modellierung von Deichen und vereinfachte GIS-basierte Überflutungssimulationen

Krüger, Tobias 03 November 2009 (has links) (PDF)
In der Arbeit werden Möglichkeiten des Einsatzes von Digitalen Geländemodellen (DGM) im Kontext des Hochwasserrisikomanagements aufgezeigt, wobei die Anwendung hochauflösender Laserscandaten im Fokus steht. Zunächst wird die Notwendigkeit der wissenschaftlichen Auseinandersetzung mit Hochwassergefahren hervorgehoben. Dies schließt die Betrachtung der Bedeutung von Geodaten (insbesondere DGM) im Hochwasserrisikomanagement ein. Es folgt eine Darstellung der verwendeten Daten, begleitet von einer Zusammenstellung von Methoden zur großflächigen Erfassung des Georeliefs und einer kurzen Einführung in die Hochwassermodellierung. Die wissenschaftlichen Arbeitsziele werden im Kontext eines interdisziplinären Projektes zur Hochwasserrisikoforschung definiert, in welchem DGM erstmals auch als dynamische Komponente des Risikosystems aufgefaßt werden. Die Arbeitsziele umfassen in diesem Zusammenhang die Entwicklung von automatisierten Methoden zur Gewinnung von Informationen über Deiche, insbesondere über deren genaue Lage und Höhe, und zur Modellierung von Deichgeometrien. Nach der Umsetzung und Erprobung der Verfahren in einem Geoinformationssystem wird der Prototyp einer Softwareanwendung vorgestellt, der eine automationsgestützte und nutzerfreundliche Realisierung der entwickelten Methoden erlaubt. Der Teil Deichmodellierung in Digitalen Geländemodellen beschreibt theoretische Grundlagen zur Realisierung eines speziell auf Hochwasserschutzdeiche ausgerichteten Geoinformationssystems. Es wird der Begriff des Digitalen Deichmodells (DDM) eingeführt und dessen Modellstruktur sowie Möglichkeiten zu Datenerfassung und -pflege mittels hochauflösender Laserscan-DGM erläutert. Weiterhin werden bestehende Methoden der Objekterkennung in DGM zum Zweck der Deichdetektion und -extraktion adaptiert und ein neues Verfahren entwickelt, das speziell die geometrischen Spezifika von Deichen berücksichtigt. Mit den vorgestellten Verfahren wird deren weitgehend automatisierte Erfassung und Kartierung ermöglicht. Das DDM wird derart konzipiert, daß sowohl Rückbau, Verlegung als auch die Erhöhung von Deichen im Modell umsetzbar sind. Damit wird letztlich die Simulationsfähigkeit bzw. Veränderlichkeit eines DGM als Basis für Hochwassersimulationen realisiert. Im Kapitel Vereinfachte GIS-basierte Überflutungssimulationen wird ein Konzept zur vereinfachten GIS-basierten Folgenabschätzung von Deichbrüchen vorgestellt. Dafür werden bestimmte Modellannahmen getroffen und zur Überflutungsmodellierung herangezogen. Die Ergebnisse werden im Rahmen der Modellannahmen kritisch als Möglichkeit der Abschätzung von im Extremfall zu erwartenden Wasserständen in Überschwemmungsgebieten bewertet. Nach der Dokumentation der praktischen Umsetzung der vorgestellten Verfahren werden die Ergebnisse diskutiert und Ausblicke zur nötigen bzw. möglichen weiteren Forschungsarbeiten gegeben. Der Anhang der Arbeit enthält Karten und eine Dokumentation des Programms Diketools, das als Prototyp einer Deichmodellierungssoftware implementiert wurde. / This study examines possibilities of using Digital Terrain Models (DTM) in the context of flood risk management. Thereby the focus lies on the application of high-resolution laserscan data. First the necessity of the scientific examination of flood hazards is underlined which implies the consideration of geodata (especially DTM). This is followed by an overview of methods of large-area data acquisition of the earth surface as well as a short introduction into flood modelling. The scientific objectives of this study are defined within the context of a multidisciplinary research project which for the first time considers DTM as a dynamic component in the flood risk system. The objectives resulting from this point of view comprise the development of automated methods of acquiring information on dikes. Here the exact locations of dikelines and their crest levels are of special interest. The modelling of new dike geometries and their implementiation into existing DTM data is also included. Chapter 4 (Deichmodellierung in Digitalen Geländemodellen, engl.: Dike Modelling in Digital Terrain Models) describes the theoretical fundamentals of the realisation of an information system focused on flood protection dikes. Here the term Digital Dike Model (DDM) is introduced. Accordingly its model structure is defined and possibilities of data retrieval and data management by means of high-resolution laserscan terrain models are shown. The detection and extraction of dikes is accomplished by the adaption of existing object-extraction methods. Also a new procedure has been developed which accounts for dike-specific geometrical characterisations. The presented methods enable the automated identification and mapping of dikes. The Digital Dike Model has been designed to allow the removal and relocation of dikes as well as their heightening within the model. Hereby the desired changeability of Digital Terrain Models is realised as a basis for flood simulations. In Chapter 5 (GIS-basierte Überflutungssimulationen, engl.: Simplified GIS-based Flood Modelling) a concept for a simplified estimation of dike-breach induced floodings by means of GIS-based procedures is presented. This implies the definition of certain model assumptions which are adopted when performing flood simulations. The results are discussed and the use of this method for estimating maximum flood impacts is evaluated. These parts of the thesis are followed by the discussion of the results. In the end an outlook for further research is given. The appendix of this work includes maps and a documentation of the Diketools which has been implemented as a prototype of a dike-modelling software.
172

The use of GIS for hazard mitigation for historic resources

Cynkar, Grace Alexandra 07 July 2011 (has links)
Geographical Information Systems (GIS) offers preservationists a unique tool with the potential to revolutionize hazard mitigation for historic resources. The program’s ability to link information to a specific geographical location and efficiently disperse this information can solve two of the most destructive issues of current natural disaster response practices: a lack of organized information and an efficient means of disseminating this data. The resources necessary to implement a GIS program and to the requisite cooperation between both public and private preservation organizations may seem prohibitive to many preservation programs; yet, the benefits make this initial investment cost-effective. Despite efforts to mitigate disasters, both natural and man-made, their effects constantly threaten historic resources. In the past two decades, the United States has made significant strides toward a greater protection of these sites; yet damage continues to occur. In this thesis, I have investigated methods of risk mitigation implemented in the United States at both the state and local level, and in the public and private sectors, using New Orleans, Louisiana after Hurricanes Katrina and Rita as a case study. Through this analysis, I discovered that a lack of accessible, organized information and cooperation between preservationists compounded the damage caused by the actual event itself. I argue that the implementation of GIS could solve many of these issues by providing a means of both consolidating data and distributing it among responders. In this work, I demonstrate the ability of GIS to easily solve the problems of current mitigation practices for historic resources. By discussing the tools and basic functions of the program, I clearly illustrate this utility to those unfamiliar with the program, while arguing its potential as a mitigation implement to all preservationists. / text
173

Ειδική περιβαλλοντική - οικιστική μελέτη του συμπλέγματος λιμνοθαλασσών Μεσολογγίου - Αιτωλικού με τη χρήση Γεωγραφικών Συστημάτων Πληροφοριών (G.I.S) / Environmental study of the lagoons system Mesolongiou - Aitolikou with the use of Geographical Information Systems

Λαγκαδινού, Μαρία 28 June 2007 (has links)
Ο σκοπός της εργασίας αυτής είναι η πραγματοποίηση μιας περιβαλλοντικής μελέτης για την ευρύτερη περιοχή του συμπλεγματος λιμνοθαλασσών Μεσολογγίου - Αιτωλικού με τη χρήση Γεωγραφικών συστημάτων Πληροφοριών. Στην ερσασία αυτή γίνεται μια προσπάθεια χαρτογράφησης με την βοήθεια των ΓΣΠ με τους ακόλουθους στόχους¦ 1. Τη δημιουργία μιας βάσης σύγκρισης για τον συσχετισμό γεωλογικών και εδαφολογικών στοιχείων,και 2. Την εύρεση προτεινώμενων περιοχών, όπου μπορεί να αναπτυχθεί ένα μοντέλο οργανωμένης Οικιστικής Ανάπτυξης που θα πληρεί όλες τις προϋποθέσεις που θέτει το Υ.ΠΕ.ΧΩ.ΔΕ / The purpose of this work is an environmental study of the lagoons system of Mesolongi - Aitoliko with te use Geographycal Information Systems,with the two following directions: 1. To create a base of comparison between the geological and the soil data,and 2. To show an area where a new city could take place that follows all the instractions of Y.ΠΕ.ΧΩ.ΔΕ
174

An investigation into using GIS in electrification and network planning in rural KwaZulu-Natal.

Barnard, Jennifer B. January 2006 (has links)
The South African Government has set a target of universal access to basic electricity by the year 2012. Free basic electricity is defined as the amount of electricity sufficient to provide basic lighting, media access, water heating and ironing with on-grid electricity; or basic lighting and media access for a non-grid system. Eskom Distribution, in conjunction with local municipalities, is responsible for the outstanding electrification predominantly in rural areas. In KwaZulu-Natal, mountainous terrain and scattered settlement patterns of communities complicate the achievement of this goal. This study was aimed at using GIS to address the urgent need to plan electrification, firstly by identifying areas that need electrification and secondly by prioritising those areas according to set principles. Electrification areas were effectively identified and prioritised from both a need and capability of supply aspect. The study then aimed at designing the shortest networks from the grid to those identified electrification areas. To determine electrification areas spatially, electoral areas (EAs) demarcated as rural during the run up to the 1994 elections were used to identify rural areas; and Ethekwini Metropolitan Municipality, current electrification projects, reserves and a buffer zone around existing transformers excluded. Household point data was used to polygonize the remaining area, and those polygons were aggregated on their calculated area to create future rural electrification areas (FREA). A points and weighting system; based on one initially used in Namibia and further developed in an electrification planning model by RAPS Consulting, CSIR and DME to prioritise villages for electrification; was applied to calculate point scores for each FREA and other criteria such as distance from a network with capacity considered to determine a prioritised list of FREA that can be electrified immediately. Roads, land cover, household positions and slope were used to design the shortest path from the grid to the three highest scoring FREA. Each layer was reclassified, ratings applied and the layers combined to successfully determine the final path in terms of the criteria used. Interest in using GIS for spatial planning has led to a GIS Initiative Group (GISIG) being formed at Eskom Distribution in Eastern Region to address data collection, co-ordination of planning, tools written previously but never implemented being re-evaluated and, more recently, new tools being designed. However, much is still needed in terms of research, resolving of data quality issues, testing of points and weighting systems, and for functionally independent sections to work together on making changes to age-old system structures and processes before any of the recommendations resulting from this study can be effectively implemented. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
175

Geographical Information Systems Based Microzonation Map Of Eskisehir Downtown Area

Kolat, Cagil 01 September 2004 (has links) (PDF)
The purpose of this study is to prepare a geotechnical microzonation map regarding the suitability of the residential areas in EskiSehir downtown area. In order to obtain the microzonation map, Geographical Information Systems (GIS) based Multicriteria Decision Analysis (MCDA) is used. For this analysis, the slope, flood susceptibility, soil, depth to groundwater table, swelling potential and liquefaction potential layers are prepared. The weight values to the layers and rank values to the classes of each layer are assigned by applying Simple Additive Weighting (SAW) and Analytical Hierarchical Process (AHP) methods. Two geotechnical microzonation maps are obtained as outputs of these methods. The study area is categorized into three different zones regarding the foundation suitability of residential areas as: (1) Areas suitable for settlement / (2) Provisional settlement areas / (3) Areas requiring detailed geotechnical investigations. The maps prepared using SAW and AHP methods are found to be consistent with each other. The geotechnical microzonation map prepared using AHP method is recommended as the final map of the study area.
176

An Attempt To Classify Turkish District Data: K-means And Self-organizing Map (som) Algorithms

Aksoy, Ece 01 January 2005 (has links) (PDF)
ABSTRACT AN ATTEMPT TO CLASSIFY TURKISH DISTRICT DATA: K-MEANS AND SELF-ORGANIZING MAP (SOM) ALGORITHMS Aksoy, Ece M.S., Department of Geodetic and Geographic Information Systems Supervisor: Assoc. Prof. Dr. Oguz ISik December 2004, 112 pages There is no universally applicable clustering technique in discovering the variety of structures display in data sets. Also, a single algorithm or approach is not adequate to solve every clustering problem. There are many methods available, the criteria used differ and hence different classifications may be obtained for the same data. While larger and larger amounts of data are collected and stored in databases, there is increasing the need for efficient and effective analysis methods. Grouping or classification of measurements is the key element in these data analysis procedures. There are lots of non-spatial clustering techniques in various areas. However, spatial clustering techniques and software are not so common. This thesis is an attempt to classify Turkish district data with the help of two clustering algorithms: K-means clustering and self organizing maps (SOM). With the help of these two common techniques it is expected that a clustering can be reached, which can be used for different aims such as regional politics, constructing statistical integrity or analyzing distribution of funds, for same data in GIS environment and putting forward the facilitative usage of GIS in regional and statistical studies. All districts of Turkey, which is 923 units, were chosen as an application area in this thesis. Some limitations such as population were specified for clustering of Turkey&rsquo / s districts. Firstly, different clustering techniques for spatial classification were researched. K-Means and SOM algorithms were chosen to compare different methods with Turkey&rsquo / s district data. Afterward, database of Turkey&rsquo / s statistical datum was formed and analyzed joining with geographical data in the GIS environment. Different clustering software, ArcGIS, CrimeStat and Matlab, were applied according to conclusion of clustering techniques research. Self Organizing Maps (SOM) algorithm, which is the best and most common spatial clustering algorithm in recent years, and CrimeStat K-Means clustering were used in this thesis as clustering methods.
177

Cevre Kale: Applications Of Newly Developed Methods, Technology And Data For Understanding The Iron Age City In Yarasli

Ozguner, Nimet Pinar 01 April 2006 (has links) (PDF)
The purpose of this thesis is to test the validity of applications of Remote Sensing and Geographical Information Systems in Anatolian archaeology. The focus of the study is an Iron Age fortress &Ccedil / evre Kale and its associated structures. During the course of the study, 5 km long outer wall enclosing a territory around &Ccedil / evre Kale documented for the first time by employing high altitude aerial imagery. In addition to the GIS analyses, examination of the geology, land use and soil quality data showed that the outer wall is in a way acting to guard and protect inhabitants of the fortress and, perhaps more importantly, the well-watered pasture surrounding the fortress and demarcated by the enclosure wall. Evaluation of the available archaeological and historical evidence suggested that &Ccedil / evre Kale might be of a site with significant military importance at least in the first half of the 6th century BC. As a result, this thesis is underlying the importance of high and low altitude aerial imagery in terms of documentation, evaluation and monitoring of the archaeological sites as part of the archaeological research
178

Geographical information systems and natural resource management in Zambia : a dissertation presented in partial fulfilment of the requirements for a Masters degree in Environmental Management at Massey University, Palmerston North, New Zealand

Mwape, Ackim January 2010 (has links)
Natural resources play a critical role in the welfare of developing countries. In Zambia, even though its vast natural resources have been important to its economy as well as its people, their exploitation has resulted in severe land and environmental degradation in most parts of the country. Reliable information as to the exact extent and degree of natural resources problems is critically lacking. For effective control and management of these natural resources problems, timely, up‐to‐date, accurate and complete spatial data are needed. The integrated application of Geographical Information Systems (GIS) and remote sensing to model natural resources management data, especially at regional level, is presented in this dissertation. Three case studies in Zambia are presented and free, internet‐based, datasets are used to demonstrate the application of GIS to support natural resource management decisions in Zambia. The results of the case studies show that while data‐gathering obstacles remain in the use of GIS in Zambia, the systems can be used successfully to fill gaps in decision‐making in natural resources management. The results of the case studies have been used to make recommendations as a way forward for the use of GIS and remote sensing data in natural resource management in Zambia. Finally, selected technical issues associated with data access, data incompatibility and data accuracy are identified as important areas of future research.
179

Remote sensing aided spatial prediction of forest stem volume /

Wallerman, Jörgen, January 2003 (has links) (PDF)
Diss. (sammanfattning) Umeå : Sveriges lantbruksuniv., 2003. / Härtill 4 uppsatser.
180

Near-optimum cost minimisation of transporting bioenergy carriers from source to intermediate distributors

Roberts, Theari 03 1900 (has links)
Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The world is facing an energy crisis with worldwide energy consumption rising at an alarming rate. The effects that fossil fuels have on the environment are also causing concern. For these two reasons the world is determined to find ‘cleaner’, renewable and sustainable energy sources. The Cape Winelands District Munisipality (CWDM) area has been identified as the study area for a bioenergy project. The CWDM project aims to determine the possibility of producing bioenergy from lignocellulosic biomass, and transporting it as economically as possible to a number of electricity plants within the study area. From the CWDM project a number of research topics were identified. The aim of this thesis is to determine the best location for one or more processing plants that will maximise the potential profit through the entire system. This is achieved by minimising the overall life cycle cost of the project. It takes into account costs from establishing and maintaining the crops, harvesting, transportation, conversion and generation; with a strong focus on the transport costs. In conjunction with a Geographical Information Systems (GIS) specialist and taking into account various factors such as electricity demand, heat sales and substation locations, 14 possible plant locations were identified. The possible supply points for each of the 14 plant locations were then analysed by GIS again to yield data in terms of elevation, road distances and slope. The transport costs were calculated using the Vehicle Cost Schedule (VCS) from the Road Freight Association (RFA) and fuel consumption calculations. It takes into account slope, laden and unladen transport and considers different transport commodities. These calculations together with the other associated costs of the life cycle are then combined with the results of the GIS into an EXCEL file. From this a transportation optimisation model is developed and the equivalent yearly life cycle cost of each of the 14 demand points are minimised by means of LINGO software. Initially runs were done for 2.5 MW capacity plants. From the high profit areas identified here, a single area was chosen and further runs were done on it. These runs were performed to determine the effect of different plant capacities on the life cycle costs, as well as how it affects the farm gate price that can be paid to the farmer. It also determined the effect of farmer participation at different plant capacities. The results indicate that it is currently possible to pay a farmer between R 300.00 and R 358.00 for a ton of biomass. It also revealed that with higher participation from farmers in the CWDM project, lower costs and higher farm gate prices will result, since the transport costs will be lower. Although all the costs within the life cycle are variable over time, the transport cost is the only cost that varies spatially and this will have a major effect on the overall system cost. The thesis found that generating electricity from woody biomass is feasible for all areas that were considered as well as for all variations considered during the sensitivity analysis. For the recommended plant size of 5 MW the transport of logs will be optimum. / AFRIKAANSE OPSOMMING: Die tempo waarteen energieverbruik wêreldwyd styg is ʼn rede tot kommer. Die nadelige effek wat fossiel brandstowwe op die omgewing het, is ook ʼn probleem. Hierdie twee redes is hoofsaaklik wat die wêreld dryf om ‘skoner’ hernieubare en volhoubare energie bronne te vind. Die Kaapse Wynland Distrik Munisipaliteit (KWDM) area is identifiseer as ʼn studie area vir ʼn bio-energie projek. Die doel van die KWDM projek is om die vervaardiging van bio-energie vanaf plantasies, die vervoer van hierdie bome sowel as die prosessering koste by die fabriek te bepaal en te evalueer. Vanuit die KWDM projek het `n aantal tesisse ontwikkel waarvan hierdie een is. Die doel van hierdie tesis is om die beste posisie vir een of meer prosesserings fabrieke te bepaal wat die potensiële wins van die KWDM projek sal maksimeer. Dit is ook gemik daarop om die ekwivalente jaarlikse oorhoofse lewenssiklus koste van die projek te minimeer. Dit neem die vestiging en onderhoud van gewasse, oeskostes, vervoerkostes en proseskostes in ag, met ʼn spesifiek fokus op die vervoerkoste. In samewerking met `ʼn “Geographical Information Systems” (GIS) spesialis en deur verskeie faktore, soos elektrisiteitsverbruik, inkomste vanaf hitte verkope en substasie posisies, in ag te neem is 14 moontlike fabriek posisies identifiseer. Verder is die moontlike voorsienings areas van elk van die 14 fabriek posisies weer deur GIS analiseer om resultate in terme van hoogte bo seespieël, padafstand en helling te verkry. Die vervoerkostes is verkry vanaf die “Vehicle Cost Schedule” (VCS) van die “Road Freight Association” (RFA), asook berekeninge wat die brandstof verbruik in ag neem. Hierdie kostes sluit in die effek van gradiënt, gelaaide en ongelaaide vervoer sowel as verskillende vervoer produkte. Hierdie berekeninge sowel as die ander kostes in die siklus en die resultate van GIS is kombineer in ʼn EXCEL leer. Hierdie data word dan gebruik om ʼn LINGO model te ontwikkel en die oorhoofse lewenssiklus koste van elk van die 14 fabriek posisies te minimeer. Optimering is gedoen vir 2.5 MW kapasiteit fabrieke. Uit die beste areas is een area identifiseer en verdere lopies is daarop gedoen. Die doel van hierdie lopies is om die effek van verskillende fabriekskapasiteit op die lewensiklus koste te bepaal, asook die effek daarvan op die prys wat aan die boer betaal word vir hout. Hierdie lopies is ook gebruik om die effek van boer deelname te bepaal. Die resultaat dui aan dat dit tans moontlik is om ʼn boer tussen R 300.00 en R 358.00 te betaal vir ʼn ton biomassa. Dit het ook gewys dat hoe meer boere deelneem aan hierdie projek hoe laer is die oorhoofse lewensiklus koste en hoe hoër is die prys wat betaal kan word vir hout aangesien die vervoerkoste laer sal wees. Alhoewel al die lewensiklus kostes veranderlik is oor tyd, is dit net die vervoerkoste wat ʼn ruimtelike komponent ook het en dit sal ʼn groot effek op die oorhoofse lewenssiklus koste hê. Die tesis bevind dat dit lewensvatbaar is vir alle areas in die studie om elektrisiteit op te wek vanaf hout biomassa, selfs al word die uiterse variasie in die sensitiwiteitsanalise gebruik. Vir die aanbeveling van ʼn 5 MW fabriek sal die goedkoopste vervoer opsie boomstompe wees.

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