IT Services and Crowdsourcing in Support of the Hellenic Cadastre: Advanced Citizen Participation and Crowdsourcing in the Official Property Registration Process

Abstract

Greece is one of the few European countries that has not yet a fully operating Cadastre at national coverage. Cadastral surveying and property registration have been completed only for about 8% of the Greek territory, which includes about 18% of the total property rights. At the remaining areas, cadastral surveying and property registration is still under development and is expected to be completed by the end of 2021. The cadastral survey is a participatory procedure in which property right holders, or their representatives, are expected to declare the land parcels on which they have property rights and submit all documents that prove these rights. The time frame available for the declaration is 3 months, which is specific for each municipality. Right holders are now enabled to provide both spatial and descriptive information, regarding their properties and property rights, without the need of a professional. That includes the parcel’s boundary lines along with the legal documents required to validate the declaration. Each right holder, or a representative, has the option to submit a declaration over the internet through a web application without the need of a professional. Within the frame of a PhD research, several concerns were addressed such as usability, security, and scalability in order for the outcome to support its scope while respecting binding constrains. As a result, two web applications have been created to officially support the Hellenic Cadaster property rights declaration process. The suggested approach was considered a big success in terms of both public acceptance and usability as shown from the statistics collected during the first eight months of its formal operation.

A BIM-IFC Technical Solution for 3D Crowdsourced Cadastral Surveys Based on LADM

“…Thus, an alternative approach is needed for the initial implementation of both formally and informally developed urban areas, as it may empower tenure security, improve property management, formalize property markets, and enable a reduction in poverty. Practical experience has demonstrated that the utilization of cutting-edge technologies and crowdsourcing techniques in the development of 2D and 3D cadastral surveying procedures, in order to minimize the necessary time and cost, has already been achieved with very promising results [18][19][20][21]50,51].…”

“…Nevertheless, beyond these drawbacks, significant progress has been achieved in the field of 2D and 3D cadastral surveys, that may be able to minimize the time and costs involved in the necessary procedures, utilizing modern techniques and technological achievements. As was proven during earlier stages of our research, crowdsourcing techniques may be utilized for the implementation of 2D [17][18][19][20][21] and 3D [22][23][24][25][26][27] cadastral surveys, minimizing the cost of and time required for the surveys while ensuring the geometric accuracy and reliability of the collected data. Although 2D crowdsourced cadastral surveys have been tested and their pilot implementation started in some cadastral agencies [21,28], 3D crowdsourced cadastral surveys still need further investigation.…”

“…As was proven during earlier stages of our research, crowdsourcing techniques may be utilized for the implementation of 2D [17][18][19][20][21] and 3D [22][23][24][25][26][27] cadastral surveys, minimizing the cost of and time required for the surveys while ensuring the geometric accuracy and reliability of the collected data. Although 2D crowdsourced cadastral surveys have been tested and their pilot implementation started in some cadastral agencies [21,28], 3D crowdsourced cadastral surveys still need further investigation. The (re)usage of existing BIMs based on open exchange standards, such as the IFC, seems to be an interesting solution, enabling the further reduction of the costs and duration of the cadastral surveys and providing a promising result [29].…”

Design of a Crowdsourced 3d Cadastral Technical Solution

“…Practical experience has demonstrated the significant benefits in crowdsourcing geodetic measurement from multiple organisations (Haasdyk, Roberts, 2013). Web-based and mobile-based crowdsourcing solutions, have already been used in developing 2D cadastral surveying procedures in order to minimize the time and cost of the required surveys (Basiouka, Potsiou, 2014;Mourafetis et al, 2015;Basiouka et al, 2015;Gkeli et al, 2016;Basiouka, Potsiou, 2016;Apostolopoulos et al, 2018;Celt et al, 2019;Potsiou et al, 2020;Potsiou et al, 2019;Mourafetis, Potsiou, 2020). The existing 2D experience should be exploited in 3D cadastral surveys, providing a fit-forpurpose solution for the initial implementation of reliable 3D Cadastres.…”

“…The absence of a functional cadastral system enhances right holders' uncertainty regarding their rights, increases risks, time and costs in land and property transactions and mortgages, blocks the real estate market and disables poverty reduction. The indtroduction of low-cost and modern IT tools, crowdsourcing techniques, automated procedures, m-services (mobile services) and international standards, such as the LADM standard, in 2D and 3D cadastral surveys, may speed up the cadastral procedures, reduce costs, enable harmonization and exchangeability of data, and eventually may lead to the immidiate implementation of a functional 2D and 3D cadastral system, everywhere (Apostolopoulos et al, 2018;Potsiou et al, 2020;Mourafetis, Potsiou, 2020;Gkeli et al, 2017;Gkeli et al, 2018;Gkeli et al, 2019ab). The use of volunteers' mobile devices as the main mean of 2D and 3D data capture, reduces the cost and time of the overall procedure, as each one may be responsible for the declaration of his/her own properties.…”