Abstract

Historical maps are valuable resources for studying long-term landscape, settlement and environmental change, yet transforming scanned sheets into analysis-ready GIS data remains challenging. Using materials from the MAHSA project (Mapping Archaeological Heritage in South Asia), participants will work with digitised Survey of India (SoI) map sheets (1905-1950s) using hands-on exercises. MAHSA is an ongoing collaborative documentation project at the University of Cambridge, funded by Arcadia. With more maps being made available online, navigating and applying historical maps in geospatial research and documentation can be highly complex. This workshop provides a practical end-to-end, open-source workflow to access, transform, visualise, and organise historical maps using some of the latest geospatial technologies, such as IIIF, STAC, Cloud Optimized GeoTIFFs (COGs), Arches, and QGIS.

The workshop is structured around three short hands-on exercises. 1) Participants will georeference a digitised map sheet from the MAHSA Arches database, an open-source geospatial database platform using the related IIIF URL from library repositories. 2) Participants will subsequently explore a STAC catalogue of publicly released MAHSA maps, filtering by map date and extent before loading selected Cloud Optimised GeoTIFFs (COGs). 3) Participants then learn how to remove sheet margins using the MAHSA SoI Map Clipper (an internally developed open-source QGIS plugin).

The workshop concludes with a discussion of broader applications for historical map workflows and applications. Within MAHSA and beyond, historical maps support applications such as automated feature extraction, long-term landscape and settlement analysis, and many other forms of spatial analysis. In the discussion, we invite participants to provide feedback on how the presented tools might support different research and public-facing uses. As well as reflect on the challenges of IIIF and STAC to build sustainable infrastructure for the use of historical maps that can serve researchers, organisations, commercial users and the wider public.

Prerequisites

A laptop with a browser, an internet connection, and QGIS 3.44 (LTR) installed. Beginner-friendly, basic QGIS familiarity is assumed. No prior experience with IIIF, Arches or STAC is required.