A 4D GIS methodology to study variations in evaporation points on a heritage building

Building decay is a dynamic process in which time is a key factor, and moisture-induced decay is no exception to the rule. Mapping strategies may hinder timebased moisture damage assessment and control in historic buildings, however. The time factor has often been absent in the mapping methodologies deployed to date, either because the studies conducted were one-off exercises or no georeferencing was involved. This paper describes the generation of four-dimensional space from a three-dimensional geographic information system (GIS) and time series data and its use to assess the incidence of moisture, defined in terms of evaporation points, on a historic building. Taken together with the potential inherent in the application of map algebra to GIS, this approach constitutes a powerful tool for enhancing the interpretation of dynamic processes such as moisture flows and evaporation