Unmanned Aerial Vehicle Mapping for Responsible Land Administration
Due to the COVID-19 crisis the PhD defence of Claudia Stöcker will take place (partly) online.
The PhD defence can be followed by a live stream.
Claudia Stöcker is a PhD student in the research group Urban and Regional Planning and Geo-Information Management (PGM). Her supervisor is prof.mr.dr.ir. J.A. Zevenbergen from the Faculty of Geo-Information Science and Earth Observation (ITC).
Secure land rights promote tenure security, a critical factor to fight hunger and poverty, the promotion of peace, economic growth, and the sustainable use of the environment. However, a large share of the global population feels insecure about their property rights, mainly attributed to missing documentation. During the past years, geospatial innovations and alterative concepts of land tenure recording disrupt traditional means of cadastral mapping and land administration. One of these innovations refers to Unmanned Aerial Vehicles (UAVs) offering flexible, cheap, and real-time acquisition of high resolution aerial imagery. Characteristics, which are considered key for addressing current land administration challenges.
Although reported benefits seem to be auspicious, the adoption of UAVs as an innovative tool for cadastral mapping remains remarkably poor. Previous works mainly refer to data-driven and technological assets of the utilization of UAVs and do not consider societal, governance and institutional settings and needs of people and groups. To respond to this gap this thesis utilizes a socio-technical approach to explore UAV-based data acquisition workflows as a tool for responsible land administration. Moreover, this thesis emphasizes on the interrelationship of three key system elements: technology (UAVs), processes (land administration processes) and actors (stakeholders). These interrelationships are reflected in four specific research objectives. Being embedded in the EU H2020 funded international research and innovation project its4land, parts of this thesis were exemplified in the East African context, including test flights, workshops, and mapping activities.
The first part assesses the capabilities of UAV technology to match the needs of land professionals in Rwanda. A needs assessment enabled the expression of a range of land information needs across multiple levels and stakeholder sectors. Although ranked differently, the need for high-resolution, up-to-date land information was consistently identified in the final lists of all group discussions. Test flights with multiple UAVs and data processing in Rwanda proved, that UAVs are able to provide valuable spatial information for various stakeholder. However, the examination also suggests four main aspects which may reveal challenges to UAV interventions to derive land information in the context of Rwanda: 1) the hilly terrain, 2) UAV regulations, 3) ground-truthing in urban areas, 4) data processing capacities at the national land administration authority. In sum, although UAVs can play a key role in satisfying stakeholder needs, structural and capacity conditions currently present major challenges to exploit the potential of UAV data acquisition workflows.
Triggered by tremendous regulatory obstacles to fly UAVs in Eastern Africa, the second part of this thesis analyses the interface between UAV technology and stakeholders in terms of legal and regulatory frameworks. To get a better understanding of past, present and future developments of UAV regulations, a thorough literature review and a comparative analysis of national UAV regulations was conducted. Although all UAV regulations have a similar target – minimizing the risk for people and property on the ground – a distinct heterogeneity of national regulatory frameworks was investigated. However, commonalities such as mandatory platform registration, obligatory insurance coverage and standard pilot licensing procedures indicate trends towards mature national UAV regulation. Desirable trends are seen in the coexistence of hard and soft regulations and the successful international dialogue that may eventually provide a legal framework for harmonized regulatory standards.
The third part of this thesis explores the technical and operational aspect of UAV workflows and assesses different data quality measures with the aim to recommend optimal UAV data acquisition workflows. Imagery from six study areas across Europe and Africa, representing overall more than 100 different flight configurations, provided the basis for an integrated data quality assessment including various aspects of the photogrammetric processing chain. The results suggest that scene context, flight configuration, and GCP setup significantly impact the final data quality and subsequent automatic delineation of visual cadastral boundaries. Moreover, even though the root mean square error of checkpoint residuals as a commonly accepted error measure lies within a range of few centimeters in all datasets, our results show large discrepancies of the accuracy and the completeness of automatically detected cadastral features for orthophotos generated from different flight plans. With its unique combination of methods and integration of various study sites, these results and recommendations can help land professionals and bottom-up initiatives alike to optimize existing and future UAV data collection workflows.
Despite the prospects and market opportunities in land administration, there is a gap between experimentation and widespread diffusion of UAV technology. To understand the dynamics of the diffusion process of UAV technology as a tool for effective land administration, the fourth part of this thesis integrates the Framework for Effective Land Administration (FELA) and the Hype Cycle concept. The majority of experts estimated UAV technology to be in a phase in which the innovation needs to overcome initial unmet expectations to foster market development and increased adoption. The results indicate a changing importance of different FELA pathways during this process, led by alternating top-down and bottom-up dynamics. Enabling laws and policies in addition to supporting governance, accountability and institutions are found to be crucial to create a UAV-friendly national ecosystem early on in the process of technology adoption and allay exaggerated expectations. Once this ecosystem has been created, market demand is expected to surge driven by partnerships, adapted standards, tech advocacy and awareness-raising campaigns, highlighting the superiority of high-resolution data amongst other benefits of UAV technology. These insights can be used as a baseline to direct national strategic decisions towards the increased adoption of UAVs in land administration.
In conclusion, the integrated view on the socio-technical system, including stakeholders, land administration processes and UAV technology as system elements, allows identifying interactions and positive and negative dependencies. Whereas the aspects of data quality and regulations both influence but are also impacted by other elements, land data needs were found to have a critical role in the system and predominantly affect other elements as a starting point for any land tool intervention. Representing the overlap of all three system elements, the diffusion of UAV technology in land administration takes a central place. Here, the superior quality of UAV data is a key driver throughout the diffusion process. In contrast, regulations may positively or negatively affect the emergence of UAV technology, as appropriate UAV legislation presents a vital pre-condition for technology uptake. Ultimately and potentially most importantly, land data needs stimulate the scaled implementation creating a demand for up-to-date high-resolution land data.
Overall, the findings of this thesis suggest that UAV technology is a highly flexible, widely available, easy-to-use and end-user responsive data acquisition tool that complements the range of mapping tools for land administration processes side by side with satellite data and GNSS surveying. Yet, regulatory constraints, missing awareness and weak governance support currently hamper exploiting the full potential of UAV technology for land administration in many countries.