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There are a wide variety of cadastral objects, ranging from simple 2D entities such as a land parcel, to complex 3D objects such as multistory/multi-owned buildings. The complex infrastructures development happening above and below the ground complicates the processes required for defining rights, restrictions and responsibilities in 3D (3D RRRs). Even in the current, predominantly, 3D analogue cadastral system which relies on 2D drawings and representations, defining 3D RRRs is still a complicated task. With the widespread use of 3D geospatial information technologies, it is increasingly becoming easy to realise and interpret a 3D digital cadastre system. As part of the process of transition from the 2D representation of cadastre towards a 3D digital cadastre, not only will 2D representations be replaced with 3D models, but the examination workflow and its principles will also need to be able to manage 3D models. Developing principles and validation rules is a critical requirement to guarantee that the diverse cadastral data is trustable and contains enough detail to define the spatial and legal extents of ownership. This paper proposes a structured framework to define validation rules for 3D cadastral models. The paper's methodology utilises a case study approach where a plan examination process in Victoria, Australia has been analysed to investigate the principles of examining cadastral plans, and further expanded on for validating 3D digital plans. The paper concludes with a discussion on the implications of the proposed 3D validation rules and proposes future research within the topic of 3D cadastral data validation.

This study evaluates the effects of cellular automata (CA) with different neighborhood sizes on the predictive performance of the Land Transformation Model (LTM). Landsat images were used to extract urban footprints and the driving forces behind urban growth seen for the metropolitan areas of Tehran and Isfahan in Iran. LTM, which uses a back-propagation neural network, was applied to investigate the relationships between urban growth and the associated drivers, and to create the transition probability map. To simulate urban growth, the following two approaches were implemented: (a) the LTM using a top-down approach for cell allocation grounding on the highest values in the transition probability map and (b) a CA with varying spatial neighborhood sizes. The results show that using the LTM-CA approach increases the accuracy of the simulated land use maps when compared with the use of the LTM topdown approach. In particular, the LTM-CA with a 7 × 7 neighborhood size performed well and improved the accuracy. The level of agreement between simulated and actual urban growth increased from 58% to 61% for Tehran and from 39% to 43% for Isfahan. In conclusion, even though the LTM-CA outperforms the LTM with a topdown approach, more studies have to be carried out within other geographical settings to better evaluate the effect of CA on the allocation phase of the urban growth simulation.

The world’s rising urban density expansion has resulted in a proliferation of attempts to efficiently use space and a higher level of spatial complexity in metropolitan areas. 3D geospatial data models are increasingly being embraced to facilitate communicating the spatial dimensions of complex built environments in different applications. For example, the use of 3D models in land administration systems has been recognized as a good approach for communicating the spatial complexity of legal spaces within multi‐storey buildings. The spatial extent of legal space—to which rights, restrictions and responsibilities relate in a 3D digital cadastre—needs to be accurately defined and geometrically closed; watertight. Therefore, this study aims to address the challenges regarding checking the closure of diverse 3D legal spaces and engage several techniques to formulate the watertight concept for cadastre. The research’s methodology is built on a 3D polyhedral surface using a half‐edge data structure. A primitive check is employed to assess the spatial consistency of lower‐dimensional primitives of 3D objects. Subsequently, advanced closure checks ensure the closure of volumetric legal spaces represented by 2‐manifold and non‐2‐manifold data models. The article concludes that, by adopting the proposed approaches, the internal spatial consistency of legal spaces in urban land administration will be certified.