A Quantitative Comparison of Completely Visible Cadastral Parcels Using Satellite Images:A Step towards Automation

Estimates suggest that 70 percent of the world’s population has little or no access to formal land administration systems and hence their rights are often neither recognized nor secured by governments. A system of organized land rights information, embedded in a broader land administration system, is argued as a key pillar for underpinning any sustainable economy and equitable economic development. Cadastres are a core ingredient of any land administration system. Traditional methods for cadastral surveying and mapping are however, often lengthy and labor intensive. In response, remote sensing based techniques have great potential and are being increasingly employed for rapid creation and upgrading of cadastral maps: the Global Land Tool Network (GLTN)’s fit-for-purpose (FFP) land administration guidelines provide ample evidence in this regard. Furthermore, (semi)-automatic methods for detecting cadastral boundaries are currently under development. These methods seek to make use of very high resolution (VHR) satellite images or sensors capable of similar resolutions. Creating approaches that are both highly automated and transferable between contexts remain a challenge owing to diverse morphologies of parcel boundaries found across contexts. Anyhow, object-based image analysis methods appear highly promising as they mimic the human interpretation process to identify features from an image. A pre-step to utilizing any of these methods should be determining the quantity of the boundaries that are actually identifiable through visual interpretation. Therefore, in this paper, we assess the quantity of visible/non-visible boundaries in different contexts with the aim of determining the percentage of known cadastral parcels that are completely visible via VHR satellite images. For this purpose, we selected subsets from case locations in the contexts of Ethiopia, Ghana, Kenya, Mozambique, Rwanda, Guatemala and Nepal. To cover different landscapes, a combination of rural, peri-urban and urban areas were included. In each case, control cadastral data (i.e. vector files or existing cadastral maps) served as a reference for the assessment. Results show significant difference between visual identification for the samples from seven contexts. The percentage of completely visible cadastral parcels ranged from zero to 71 percent when compared to the reference cadastral map. These were parcels for which all boundaries were fully visible, i.e. a closed polygon. Considering the result of the study, it appears that (semi)-automated cadastral boundary extraction methods using VHR imagery will have high utility in specific contexts (e.g. smallholder and rural), whereas their use in complex urban environments may be challenging and require other methods or data. Nonetheless, an approach like this will greatly enhance the application of FFP approach in Land Administration for cadastral mapping in areas where no relaible data exists, for e.g. even if a small amount of boundaries could be automatically generated (e.g. 30 percent), potentially large cost reductions in cadastral surveying and mapping could be achieved

Its4land - Innovative geospatial tools for fit-for-purpose land rights mapping

Mapping millions of unrecorded land rights in large parts of Sub-Saharan Africa remains a challenge. The results of many existing ICT-based approaches for recording these rights have often proven to be inappropriate; therefore, a new generation of tools needs to be developed to map land rights faster, cheaper, easier, and more responsible. This is the main goal of its4land, a European Commission Horizon 2020 project that aims to develop innovative tools that respond to the continuum of land rights, fit-for-purpose approach, and provide cadastral intelligence. To deliver innovative, scalable, and transferrable ICT solutions, the its4land project builds on strategic collaborations between the EU and East Africa. The innovation process incorporates a broad range of stakeholders and emergent geospatial technologies including smart sketch maps, Unmanned Aerial Vehicles (UAVs), interactive feature extraction, as well as sharing and publishing land information through geocloud services. The aim is to combine these innovative approaches with the specific needs, market opportunities and readiness of end users in the domain of land recording in East Africa. Moreover, the land recording tools target both top-down and bottom-up approaches and thus support formal land registration processes, as well as informal community-based land resource documentation. The project consists of a four-year work plan, €3.9M funding, and eight consortium partners collaborating with stakeholders from different case study locations in Ethiopia, Kenya, and Rwanda that cover different land uses such as urban, peri-urban, rural smallholder, and (former) pastoralists. Major technical tasks include tool development, prototyping, and demonstration for local, national, regional, and international interest groups. However, equal emphasis is placed on needs assessment, as well as governance, capacity and business modelling. This paper will present the unique its4land land administration toolbox in which the exploitable results of the its4land project are integrated. It will describe each of these exploitable results which cover different software tools for recording land tenure information based on hand-drawn sketch maps, UAV-driven workflows for land tenure data acquisition, and semi-automatic and interactive delineation of visible cadastral boundaries, all integrated in a software platform to publish and share land information via geocloud services. The toolbox also combines consultancy services in the fields of needs assessment, and the development of governance and capacity building models for innovative technologies