Data integration and standardization in cross-border hydrogeological studies: a novel approach to hydrostratigraphic model development

Data integration-or the merging of multiple source data sets-is central to hydrogeological studies. In cross-border situations, data heterogeneities are the source of most integration problems. Semantic integration of the subsurface geological terms is undertaken for the Abbots-ford-Sumas aquifer, a cross-border (trans-national) aquifer, which is equally shared by British Columbia (Canada) and Washington State (US). Subsurface information is largely derived from water well information submitted to the respective governments. Use of this information is constrained due to inconsistent use of geological terms in water well reports. Lack of standardized methodology resulted in 6,000 unique geological descriptions for the aquifer alone. Semantic standardization of geological descriptions progressed from database interpretation to domain expert interpretation. Despite the poor quality of water well information, trends were observed that facilitated the development of a hydrostratigraphic model that honors the generalized early conceptual models of the aquifer, but provides a much higher degree of resolution in the stratigraphy necessary for groundwater flow modeling. The standardization protocols introduced support the model creation despite the constraint of poor quality data.