Mapping of multi-scale relief patterns and territorial planning: Applications at the Geological Survey of Brazil

Comparative Practices in 3-D Geoinformation by National Mapping and Cadastral Agencies

Abstract. The rapid evolution of three-dimensional (3-D) geospatial science has redefined the standards of national mapping and cadastral agencies (NMCAs). Traditionally bodies of authoritative 2-D topographic products, these organisations now face the challenge of producing, maintaining, and disseminating national-scale 3-D geospatial datasets that support applications ranging from climate adaptation and urban planning to disaster response and digital twins. This paper presents a comparative study of five NMCAs, comprising IGN (France), BKG (Germany), Kadaster (The Netherlands), GSI (Japan) and USGS (United States of America). By examining agency structure, economic models, and 3-D data collection programmes, this paper identifies converging trends in AI integration, national surveys, along with divergences in funding and implementation. The analysis highlights insights and potential lessons for organisations at early stages of national 3-D dataset implementation.

GEOMORPHOLOGICAL CONSTRAINTS AND LAND USE DYNAMICS IN A BRAZILIAN CERRADO PROTECTED AREA: RIO PANDEIROS ENVIRONMENTAL PROTECTION AREA

This study aims to analyze the influence of geomorphological units on land use and land cover changes within the Environmental Protection Area of Rio Pandeiros basin, located in northern Minas Gerais, Brazil, in the years 1985, 2000, 2010, and 2024. The present research stems from the need to understand how relief conditions the dynamics of land occupation in protected areas within the Cerrado biome. The methodological approach integrated geomorphological mapping based on morphometric variables derived from the SRTM Digital Elevation Model (DEM) and supervised classification of Landsat imagery using the Random Forest algorithm, and incorporating spectral and topographic covariates. The results indicated high model performance, with strong classification accuracy across all years analyzed. It was observed that anthropogenic transformations were predominantly concentrated in flat relief areas, especially in structural bencheslateau, where pasture emerged as the main anthropogenic class, increasing from 22.99% of the area in 1985 to 26.92% in 2024. In contrast, more dissected compartments showed greater conservation of native vegetation. The findings suggest that geomorphology plays a determining role in the spatial organization of land uses, constituting an essential variable for territorial planning and management in conservation units.

Geomorphologic Mapping of Tete Municipality, Mozambique

Geomorphological mapping consists of a set of techniques used to map landforms and the processes acting on the Earth's surface. It is a combination of techniques used in the representation of landforms and a useful tool to support information for integrated environmental analyses, territorial management, and geo-environmental risk assessment. Despite its importance and widespread use in several countries, including Brazil, most African countries do not conduct this type of mapping in their territories. This article aims to present the geomorphological mapping of the municipality of Tete in Mozambique. The methodology employed included the use of a Digital Elevation Model (DEM), high-resolution optical images, and fieldwork. The definition and classification of landforms followed the system proposed by Latrubesse and Carvalho (2006), which is nationally recognized and adaptable to different environments. The results indicate that the municipality's area is dominated by denudational units (~208 km²), which have sculpted large Receding Erosion Zones and Planation Surfaces, exhibiting different evolutionary stages. The aggradational units (~85 km²), in turn, are associated with the current and past dynamics of the Zambezi and Revúboè river systems. This study represents a pioneering product in the region and aims to provide support information for urban planning, environmental management, and hydrogeomorphological risk mitigation actions in the municipality of Tete.

3D models from geological maps: strengths and weaknesses from the Pasubio Massif (Southern Alps)

3D geological models provide digital representations of subsurface architecture and are increasingly applied in both academic research and industry. Their construction can follow implicit or explicit approaches, depending on data availability and final modelling applications. While 3D models based on subsurface data are traditionally employed in several fields of study, models derived from outcrop data are increasingly being developed. In this study, newly acquired geological mapping data from the Pasubio Massif (Southern Alps, northern Italy), covering an area of ~36 km² within the geographic extent of the CARG sheet 081 “Rovereto”, were used to develop and test an iterative explicit workflow for 3D geological modelling using Move software. The workflow is based on the construction of a structured grid of geological cross-sections, followed by the interpolation of stratigraphic horizons and fault surfaces through Ordinary Kriging. Field observations indicate that the lithostratigraphic units cropping out in the study area form a gently NW-dipping monoclinal structure, exhibit overall constant thicknesses and are affected by the Schio-Vicenza fault system. Model validation first involved a qualitative comparison between mapped geological boundaries and faults with those obtained from the intersection of the modelled surfaces with the topography (DEM), followed by thickness maps evaluation as an internal consistency check. Where inconsistencies emerged, cross-sections were refined and the model was iteratively updated until geological geometries and thickness trends became consistent with field-mapped evidence. A final quantitative assessment was then performed by analysing thickness deviations from mean unit thicknesses and by measuring the spatial overlap between mapped and model-interpolated geological boundaries and fault traces. Comparison between the preliminary and validated models, supported by thickness deviation statistics, indicates that most residual discrepancies are constrained within ±10–20% of expected thickness values. The results highlight the critical role of iterative validation in ensuring geologically robust 3D models, emphasising common sources of uncertainty in explicit geomodelling workflows. This study provides a methodological framework for producing reliable 3D geological models in data-poor regions, complementing the recently published ISPRA guidelines for the organisation and standardisation of model datasets and supporting future applications in academic research and regional or national geological surveys.

Geological Suitability and Urban Development: A GIS-Based Assessment of the City of Valjevo, Serbia

Geological conditions fundamentally constrain land-use suitability, terrain stability, and long-term sustainability, yet they remain underutilized in urban planning frameworks. This study presents a GIS-based geological suitability assessment model, tested on the City of Valjevo, Serbia, integrating lithological, structural, land use/land cover change and spatial data to guide urban development decisions. Seven lithological units—Quaternary deposits, lacustrine sediments, carbonate rocks, volcanic and pyroclastic rocks, ophiolites, ophiolitic mélanges, and Jadar Block sediments—were classified into four suitability classes based on lithological composition, structural characteristics, and rock mass behavior. An Integrated Geological Index (Igeo) was derived using an area-weighted approach across a regular hexagonal grid, enabling spatially explicit suitability mapping. Comparison with land use/land cover changes for 2012–2021 revealed a notable mismatch between geological suitability and observed development patterns: favorable and conditionally favorable terrains cover 72.5% of the study area but account for only 48.7% of recent urban expansion, while unfavorable terrains, occupying just 20.9% of the territory, absorbed 51.3% of new development. No expansion occurred within highly unfavorable terrains. These findings expose critical gaps in integrating geological criteria into planning practice and demonstrate a reproducible methodology for embedding geological suitability into sustainable urban development strategies across geologically heterogeneous regions.

Modeling alpine geomorphology using laser altimetry data