SPARTA guide
How can an LGU digitize cadastral and tax maps?
Scanning and tracing are only the beginning. The office also needs to know where every parcel line came from and how to handle conflicting records.
Inventory and scan the source
Record each sheet's title, scale, identifiers, date if shown, and source office. Scan at a resolution that preserves small labels and linework, and keep the original image available for review.
Separate cadastral index maps, tax maps, and approved survey documents by purpose. Their lines may relate to the same parcel, but they should not be treated as interchangeable authority.
Align, trace, and reconcile
Georeference sheets using reliable control information, then inspect alignment rather than trusting one point. Trace parcel geometry with consistent shared edges and attach the correct identifiers and source references.
Check for overlaps, gaps, duplicate identifiers, and parcels with no matching assessment record. Flag uncertain lines for document or field validation instead of filling gaps by guesswork.
Make the result maintainable
Track whether a feature is provisional, reviewed, or verified. Record who changed it and why. SPARTA's implementation work can combine digitization with database population, reconciliation, validation, and an office process for future updates.