22/01/2026
Technical GIS Description: Geological Map of Albay
This geological map of Albay Province represents the spatial distribution of major lithologic and stratigraphic units, classified according to age and rock composition. The map was derived from historical geological map sources and subsequently georeferenced to a modern coordinate reference system to enable accurate spatial alignment and GIS-based analysis.
The georeferencing process involved the selection of identifiable ground control points (GCPs) from stable geographic features such as coastlines, road intersections, and river confluences. A suitable transformation method was applied to minimize residual errors and ensure positional accuracy across the map extent. The finalized raster was then overlaid with administrative boundaries and basemap layers for spatial validation.
Geological units are symbolized using standardized color codes and abbreviations, including volcanic, sedimentary, metamorphic, and ultramafic formations. These units reflect geological processes such as Quaternary volcanism, Miocene sedimentation, ophiolite emplacement, and tectonic uplift, particularly associated with the Bicol Volcanic Arc and surrounding structural features.
The map provides a spatial framework for:
Geological and geomorphological analysis
Volcanic and seismic hazard assessment
Land-use planning and resource evaluation
Integration with other geospatial datasets such as DEMs, slope, and population data
Overall, the georeferenced geological map enhances the usability of legacy cartographic data by transforming it into a GIS-ready dataset suitable for spatial analysis, visualization, and decision support.
