GIS analysis of the accuracy of Tomas Lopez's historical cartography in the Canary Islands (1742 - 1746)

The accuracy of Tomás López´s historical cartography of the Canary Islands included in the “Atlas Particular” of the Kingdoms of Spain, Portugal and Adjacent Islands” is analyzed. For this purpose, we propose a methodology based on Geographic Information Systems (GIS), a comparison of digitized historical cartography population centres with current ones. This study shows that the lineal error value is small for the smaller islands: Lanzarote, El Hierro, La Palma and La Gomera. In the large islands of Tenerife, Fuerteventura and Gran Canaria, the error is smaller in central zones but increases towards the coast. This indicates that Tomás López began his cartography starting from central island zones, accumulating errors due to lack of geodetic references as he moved toward the coast.