The promotion of the data re-usability was the main motivation behind the conception of linked data. Spatial data can also be expressed as linked data. This thesis explores different approaches to utilize spatial data in linked data format, in order to determine if the technologies have matured enough to assist solving spatial problems. More precisely, it attempts to select a position to build a new shopping center in Delft, Netherlands by using relational data and linked data. Five different Linked-data implementations are identified and examined; two of them, a Geographic SPARQL Protocol and Resource Description Framework (RDF) Query Language (a recursive acronym for GeoSPARQL) (GeoSPARQL) endpoint and an API, are offered from Publieke Dienstverlening Op de Kaart (PDOK). The other three approaches are designed using Oracle Spatial and Graph. From the latter three, one approach utilizes linked data stored in a local database while the rest utilize relational data mapped into linked-data. All five approaches are assessed for GeoSPARQL compliance and are compared to a QGIS solution. From the aforementioned approaches, only the two mapping ones have achieved the desired solution. However, none of them fully complies with GeoSPARQL specification hence, further research is necessary.

Many countries in the world are extending their cadastral visualization systems in the third dimension. The reason of this, stems from the increasing complexity of contemporary cities, the growing 3D approach in other fields (including 3D spatial data acquisition, spatial data processing and visualization) which made 3D cadastre technologically feasible, and the need to overcome the issues of 2D visualization. The visualization of cadastral parcels in 3D is a huge challenge, since legal boundaries are, in some cases, invisible in the real world. Several countries built their own 3D cadastre (partial) systems/prototypes which are still lacking some crucial functionalities, therefore this research will try to fill some of the gaps of the existing cadastral systems with a special focus on visualization and dissemination aspects.
The goal of this research is to solve issues of occlusion, representation of unbounded vol- umes and ambiguous perception (in terms of position, size and shape) of objects in the con- text of 3D cadastre visualization. Additionally, the combination of topography and cadastral parcels is a double-edged sword; on one hand, it is useful for orientation purposes but, on the other hand, the growing complexity and increasing occlusion can make the visualization more challenging. The exploration of specific interaction techniques is fundamental to over- come these issues.
This document provides guidance on the system design choices to implement a 3D cadas- tre prototype. The study starts with a theoretical and a technological research carried out to investigate the state of the art in 3D cadastre visualization and to explore the existing WebGL platforms on which to build a successful prototype. Along with these phases, two lists of requirements are created; the first one related to 3D visualization issues and the second one related to the web viewer functionalities. The implementation of the prototype is carried out following (part of) the requirements listed, leaving the rest for future work. The development phase is the core of the research and includes the selection of the datasets and of the area of interest located in the city centre of Brisbane, Australia. In addition to that, the definition of the LADM compliant storage schema and the process of data encoding, to transform the data from survey plans to a cadastral database, are described. Although these steps are not in the main scope, they are crucial for the development of the prototype. After that, different visualization functionalities have been implemented, each of them presenting drawbacks and difficulties mainly related to the data format chosen.
In order to assess the usability and user-friendliness of the 3D cadastre prototype, a ques- tionnaire has been handed out to potential users of the application. Their feedback is funda- mental for this research and will provide insights on how to improve the actual design of the prototype.

In recent years, there has been a growing necessity for 3D geoinformation in urban planning and infrastructure management to provide a more realistic representation of urban areas and the built environment. A key concept in public infrastructure management is Life Cycle Asset Management (LCAM), which aims to improve the decision making in each phase of the life cycle of infrastructure assets, such as road and utility networks, civil structures, and green areas. Traditional systems in LCAM are limited in terms of analysis and visualization opportunities due to the use of simpler tools like tables. In this respect, Geographic Information System (GIS) solutions have been widely integrated in LCAM to optimise the administration and monitoring of infrastructure assets. The incursion of semantic 3D models complements the use of GIS by introducing new and innovative modelling and visualization methods. As one of the most common design techniques in the building and construction industry, Building Information Modelling (BIM) facilitates the generation of multidimensional models to describe the physical and functional characteristics of built objects. This research studies the integration of 3D BIM models in a Web GIS system for public space management to improve the procedure in the maintenance phase of LCAM. The goal is to solve the challenges related to the acquisition, processing, and visualization of 3D models. The thesis outlines the process of the development of a 3D prototype in an attempt to demonstrate a possible solution for the integration of BIM models in an existing GIS application. The research starts with a scientific literature review to familiarise with the LCAM concept, Web GIS, and semantic 3D models. Then, the stakeholders in the project are identified and their requirements with regard to the functional capabilities of the prototype are gathered in order to create a design concept. Consequently, the BIM model used in this study is presented and processed to comply with the Dutch national standards for inspection and maintenance. The prototype is developed on the basis of Web Graphics Library (WebGL), a technology for web rendering of interactive 3D graphics and animations supported by all modern web browsers. At the end of the development process, the prototype is evaluated by experts in the LCAM and BIM fields to assess its usability by means of a questionnaire survey. The input from the participants in the survey is essential for the further improvement of the prototype and its release as fully functional product.