Method of recovering municipal boundary lines in Province of Valencia (Spain) by means of historical cadastral maps

Land demarcation is a fundamental requirement when determining to what extent property owners and public administrations can apply their rights. Just as international boundaries must be clearly marked so that there can be no doubt as to which jurisdiction is to be applied, municipal boundaries must be clearly defined in order to avoid disputes between local administrations. In Spain the Geographical Institute carried out the demarcation of all municipal boundaries at the end of the 19th and beginning of the 20th centuries, defined their limits on cadastral maps and represented them on the 1 : 50 000 scale National Topographical Map. At the present time, more than a hundred years after this survey, in many cases parts of the original municipal limits have been lost for one reason or another, both on the maps and on the ground itself, and it has now become necessary to take steps to recover them. This paper defines a method of using the municipal councils' own historical information to trace original boundary lines. The work included both a study and a series of tests carried out in different municipal areas in the Province of Valencia, Spain. The original reports and field notebooks of the Geographical Institute were used as the basic material of the study, supported by cadastral maps from different periods, as well as historical and contemporary orthophotos to help locate possible boundary markers. GPS techniques were employed to look for, survey and reinstate boundary marker positions.