Estimation of the damage before and after an earthquake requires data collection and its analysis, as well. There have been many studies that performed that kind of analysis. However, the previous... Show More

Estimation of the damage before and after an earthquake requires data collection and its analysis, as well. There have been many studies that performed that kind of analysis. However, the previous studies only represent a particular period of time. There is not a good infrastructure that can perform dynamic risk analysis based on the new data collected and changing circumstances. To this end, this project aims to build an infrastructure that can enable to perform a long-term up to date analysis. In the project, it was established updateable and shareable infrastructure risk analysis for the Istanbul Metropolitan Municipality Disaster Coordination Center, Disaster and Emergency Plan, with ELER (Earthquake Loss Estimation Routine) using web-based GIS tools. ELER software that performs the loss of life and damage distribution analysis enables the implementation of disaster plans according to the pre-earthquake scenarios and post-earthquake damage distribution and amplitude results. For this purpose, web-based data entry interface of the desktop software ELER is prepared and the required update of the data set is provided. Relational database between Marmara Sea Bathymetry, 3 D terrain elevation data and geology, building data was created. Web services were given the opportunity to be updated to these data online. End products will be bringing into service to users / administrators with web-based mapping software. As a result of this project; after an earthquake in Istanbul, life loss, injuries and the quantity of the damaged buildings were quantified as soon as possible. Five-level (full, heavy, medium, light, undamaged) structural damage analyzes were done, number of people who needs post-earthquake emergency shelter was identified, and the amount of economic loss was calculated. Therefore, under the coordination of IBB units, post-earthquake intervention regions, size of the damage, etc. holistic contribution were provided, rapid damage assessment after the earthquake was made with the established system and vulnerability risk of earthquakes in the quantitative environment has become interrogable.

Artvin is one of the provinces in Turkey where landslides occur most frequently. There have been numerous landslides characterized as natural disaster recorded across the province. The areas... Show More

Artvin is one of the provinces in Turkey where landslides occur most frequently. There have been numerous landslides characterized as natural disaster recorded across the province. The areas sensitive to landslides across the province should be identified in order to ensure people's safety, to take the necessary measures for reducing any devastating effects of landslides and to make the right decisions in respect to land use planning. In this study, the landslide susceptibility map of the Central district of Artvin was produced by using Bayesian probability model. Parameters including lithology, altitude, slope, aspect, plan and profile curvatures, soil depth, topographic wetness index, land cover, and proximity to the road and stream were used in landslide susceptibility analysis. The landslide susceptibility map produced in this study was validated using the receiver operating characteristics (ROC) based on area under curve (AUC) analysis. In addition, control landslide locations were used to validate the results of the landslide susceptibility map and the validation analysis resulted in 94.30% accuracy, a reliable outcome for this map that can be useful for general land use planning in Artvin.

Usage of aerial oblique cameras and oblique images in generation of 3D city models has become popular all over the world in recent years and various solutions has been developed involving... Show More

Usage of aerial oblique cameras and oblique images in generation of 3D city models has become popular all over the world in recent years and various solutions has been developed involving specialized methods and softwares. The first comprehensive step in this field was taken by Konya Metropolitan Municipality in Turkey in 2012 and the project undertaken by GEOGIS has been successfully completed in February 2014. It is the first time in Turkey that 3D city model of this large scale has been generated. The project involves: Aerial image acquisition of the project area with vertical and oblique cameras respectively and photogrammetric triangulation; Development of OttoPenta software, which can display oblique images in pentaview screen, make spatial queries and also can measure the horizontal, vertical distance and area; Digitization of roof and roof structures from vertical stereo images using photogrammetric interpretation techniques and generation of 3D solid building models using this data; Assigning building ID numbers to solid models to integrate with the GIS data of the Municipality that is available in Oracle Spatial database; Automatic texturing of 3D models with oblique images; Exporting of textured 3D models into Oracle Spatial Database in CityGML format, complying the OGC standards; and development of KNVCity software, to create and publish the 3D city guide on WEB and mobile devices. The goal of this paper is sharing the experience and knowledge that was gained during the 3D City modeling and 3D city guide project which was performed for the first time in Turkey.

The reverse engineering applications has gained great momentum in industrial production with developments in the fields of computer vision and computer-aided design (CAD). The reproduction of an... Show More

The reverse engineering applications has gained great momentum in industrial production with developments in the fields of computer vision and computer-aided design (CAD). The reproduction of an existing product or a spare part, reproduction of an existing surface, elimination of the defect or improvement of the available product are the goals of industrial reverse engineering applications. The first and the most important step in reverse engineering applications is the generation of the three dimensional (3D) metric model of an existing product in computer environment. After this stage, many operations such as the preparation of molds for mass production, the performance testing, the comparison of the existing product with other products and prototypes which are available on the market are performed by using the generated 3D models. In reverse engineering applications, the laser scanner system or digital terrestrial photogrammetry methods, also called contactless method, are preferred for the generation of the 3D models. In particular, terrestrial photogrammetry has become a popular method since require only photographs for the 3-dimensional drawing, the generation of the dense point cloud using the image matching algorithms and the orthoimage generation as well as its low cost. In this paper, an industrial application of 3D information modelling is presented which concerns the measurement and 3D metric modelling of the ship model. The possible usage of terrestrial photogrammetry in reverse engineering application is investigated based on low cost photogrammetric system. The main aim was the generation of the dense point cloud and 3D line drawing of the ship model by using terrestrial photogrammetry, for the production of the ship in real size as a reverse engineering application. For this purpose, the images were recorded with digital SLR camera and orientations have been performed. Then 3D line drawing operations, point cloud and orthoimage generations have been accomplished by using PhotoModeler software. As a result of the proposed terrestrial photogrammetric steps, 0.5 mm spaced dense point cloud and orthoimage have been generated. The obtained results from experimental study were discussed and possible use of proposed methods was evaluated for reverse engineering application.

Urbanization has been increasingly continuing in Turkey and in the world for the last 30 years. Especially for the developing countries, urbanization is a necessary fact for the sustainability of... Show More

Urbanization has been increasingly continuing in Turkey and in the world for the last 30 years. Especially for the developing countries, urbanization is a necessary fact for the sustainability of the urban growth. Yet, this growth should be controlled and planned; otherwise, many environmental problems might occur. Therefore, the urban areas having dynamic structure should be monitored periodically. Monitoring the changes in urban environment can be provided with land cover land use (LCLU) maps produced by the pixel based classification methods using ‘maximum likelihood' and ‘isodata' techniques. However, these thematic maps might bring about inaccurate classification results in heterogeneous areas especially where low spatial resolution satellite data is used since, in these approaches, each pixel is represented with only one class value. In this study, considering the spectral mixture analysis (SMA) each pixel is represented by endmember fractions. The earth is represented more accurately using 'substrate (S)', ‘green vegetation (V)' and ‘dark surfaces (D)' spectral endmember reflectances with this analysis based on linear mixture model. Here, the surrounding of Izmit Gulf, one of the most industrialized areas of Turkey, has been chosen as the study area. SMA has been applied to LANDSAT images of the years of 1984, 1999 and 2009. In addition, DMSP-OLS data of 1992, 1999 and 2009 has been used to detect urban areas. According to the results, the changes in LCLU and especially the urban growth areas have been detected accurately using the SMA method.

This technical paper is a contribution to the identification of current challenges of semantic 3D city models. They are presented in four parts, namely 3D enriched city models and their connection... Show More

This technical paper is a contribution to the identification of current challenges of semantic 3D city models. They are presented in four parts, namely 3D enriched city models and their connection with urban information models and smartcities, urban models integration, urban analyses and data. This work is an output of the COST Action TU0801 “Semantic Enrichment of 3D city models for sustainable urban development”.