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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.
1

A Conceptual Framework For 3d Urban Disaster Risk Visualization In Geo-spatial Environment

Kemec, Serkan 01 October 2011 (has links) (PDF)
Visualization could be defined as the graphical presentation of information, in which the main aim is to improve the user&rsquo / s perception. In all phases of the disaster management, decision makers come across huge data sets with spatio-temporal content. It is hard to deal with these sets in order to find answers to the main question of &ldquo / How can we decrease the losses due to disasters?&rdquo / , which is at the core of the disaster management concept. To furnish this aim, disaster risk information has to be transparent and clearly stated to the public, decision makers and disaster managers. This might be more sophisticated than the calculation of the risk. Taking precautions before a disaster to reduce the causalities and lossess engendered by natural disasters is relatively cheaper, and more importantly, better than cure. To achieve enhanced preparations for all kinds of disasters, visualization is quite an important tool for decision support and risk communication. The basic aim of this research is to propose a conceptual framework, with the consideration of all stakeholders related to the disaster management issue to have a better risk communication, and to guide the design, implementation and integration of the 3D urban modeling tools into disaster risk visualization. Moreover, an empirical methodology is also developed for the generation of visualization solutions through the design, and employment of the tool for disaster management framework. The proposed framework has three main phases .These are the definition of visualization components, object representation, and needs assessment. A new LoD hierarchy with indoor is proposed to visualize all the possible 3D urban disaster situations in the first phase. Then, a decision rule with eight attributes is proposed in the second phase to establish a link between the hazard type and the LoD needed in a 3D urban model for visualization. This decision rule is applied in a proposed three-level hierarchycal structure. The assessed objects of these three levels are urban, sub-urban zone and building. Moreover, a method to define the needed sub-urban zone is proposed. Finally, different 3D urban modelling methods are analyzed to define the data and process needs of possible 3D urban disaster visualization situations. Two natural hazard cases are studied within the scope of this dissertation to assess the operability of the proposed framework. These implementations involve one earthquake and one tsunami case. Special attention is paid to finding one specific sample for two modelling viewpoints, namely static and dynamic. The first applications of the proposed framework with all the related features prove quite promising.
2

Improvement Of Land Cover Classification With The Integration Of Topographical Data In Uneven Terrain

Gercek, Deniz 01 November 2002 (has links) (PDF)
The aim of this study is to develop a framework for the integration of ancillary topographic information into supervised image classification to improve the accuracy of the classification product. Integration of topographic data into classification is basically through modification of training set in order to provide additional sensitivity to topographical characteristics associated with each land cover class in the study area. Multi-spectral Landsat 7 ETM 30x30 meter bands are the remotely sensed data used in the study. Ancillary topographic data are elevation, slope and aspect derived from 1/25000 scaled topographic map contours. A five-phase methodological framework was proposed for developing procedures for the integration of topographical data into a standard image classification task. Briefly / first phase is the selection of initial class spectral signatures, second phase is analyzing the information content of class spectral signatures and topographical data for a potential relationship, and quantification of the related topographical data. Third phase is the selection of class topographical signatures from the related topographical data. Fourth phase is redefinition of two training sets where one of which includes spectral information only and the other includes both spectral and topographical information. The last phase is classification. Two products were derived where, first product used bands as input and was trained by spectral information only and the second was the product for which bands and topographical data was used as input and it was trained with both spectral and topographical information. Method was applied to image and associated ancillary topographical data covering rural lands mainly composed of agricultural practices and rangelands in Ankara. Method provided an improvement of 10% in overall accuracy for the classification with the integration of topographical data compared to that depended only on spectral data from remotely sensed images.
3

Evaluating Public Transportation Alternatives In The Metu Campus With The Aid Of Gis

Gulluoglu, Cem Naim 01 December 2005 (has links) (PDF)
Geographical Information Systems (GIS) have been rapidly developed in the fields that need spatial data and transportation planning is one of these fields. Since transportation data is spatially distributed and need spatial, statistical and network based analysis / GIS applications have contributions to transportation planning. In this study, it is aimed to determine a new public transportation mode and route in the METU campus with the aid of GIS by considering the stations of &Ccedil / ayyolu metro route. Besides, it is also aimed to show that GIS can be a useful tool for constructing transport planning database and exploring, analyzing planning data. Gross settlement area of the campus, covering about 220 hectare land on the southern side of the Ankara &amp / #8211 / EskiSehir highway, is the study area of this thesis. First, campus land-use, topography, population characteristics and transportation structure are explored. Then, campus trip demand and pedestrian traffic are estimated. Afterwards, eight public transport route alternatives are proposed with their stops or stations for three different modes as / guided light transit, modern trolleybus and monorail. Proposed routes and stops or stations are evaluated with their physical characteristics and in terms of service areas shaped relative to pedestrian accessibility for determining the suitable public transport service in the METU campus. Consequently, Trolleybus B alternative is selected as the first degree suitable public transport service in campus. Besides, Monorail B and Trolleybus A services are determined as the second degree suitable services in campus.
4

A Study On Flood Management Practices For Guzelyurt

Sahin, Erdal 01 August 2012 (has links) (PDF)
This study deals with the investigation of characteristics of a flash flood and development of design of flood mitigation facilities occurred in G&uuml / zelyurt in North Cyprus on 18th of January, 2010 and development of design of flood mitigation facilities. Hydrologic and hydraulic modeling of this flood event has been utilized to develop solutions for preventing the region from the flood. Topographical maps and soil properties are used in hydrological modeling. The data are inserted into a geographical information system program (ARC-GIS) where basin properties are obtained. Since there is no any stream flow gauging station along the creeks in the study area, the synthetic unit hydrograph is developed by using Soil Conversation Service Method to obtain design flood hydrographs. In hydraulic modeling, the cross-section data of Fabrika Creek and Bostanci Creek are taken by using global navigation satellite system (GNSS) device and total station. These data are entered into the HEC-RAS program. Flood inundation maps are generated for both creeks. After hydrological and hydraulic modeling, two solutions are proposed. The first one is to build a detention basin for storing water and a lateral channel. for diverting extra flow from Bostanci Creek to Fabrika Creek. The second solution is to build a lateral channel from Bostanci Creek to G&uuml / zelyurt Dam for diverting all water during a flood event. Based on hydrologic, hydraulic, and cost analysis, the first solution is accepted to be the feasible solution. In addition, flow carrying capacities of the creeks are improved.

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