Tranchant, J.; Fenech, D.; Gauci, C.; Ghirxi, D.; Martins, I.F.; Colica, E., and Buhagiar, G., 2025. Evaluating Ordnance Survey sheets (1890s–1957) for shoreline change analysis in the Maltese Islands: Identification of differences in cartographic techniques and precision. Journal of Coastal Research, 41(1), 83–93. Charlotte (North Carolina), ISSN 0749-0208.

The assessment of coastal erosion through shoreline change analysis is an exercise of national utility undertaken in many countries. The Maltese Islands are particularly vulnerable to coastal erosion given the economic value of coastal activities and the islands' high ratio of coast-to-land surface. The integration of historical cartographic material is often used to hindcast shoreline change across long periods, as well as to model future erosion rates. The Public Works Department has produced detailed 1:2500 maps of Malta in collaboration with the British Ordnance Survey from the end of the 19^th century to 1957; however, these maps have not been scientifically assessed until now. The initial research evaluated the usefulness of the two oldest 63.5-cm Maltese map series (early 20^th century and 1957) for shoreline change analysis. The two series were digitized, georeferenced, and compared in a GIS environment to assess their differences. Inaccuracies of the original drawings, absent shoreline indicators, and the absence of a geographic coordinate system (datum and projection) were identified as limitations for their use in evaluating small gradual changes, but the series were ideal for the identification of stochastic, large-scale, historic erosion events using difference maps. This assessment showed that the two series are highly congruous and that changes between the two series are largely attributed to changes in infrastructure. There were minor exceptions, and these need to be explored case by case. These methods and the insights garnered from their production will function as scientific stepping stones toward developing a holistic coastal erosion national monitoring program.