We introduce a process-centric ontological approach to relate observed properties to geo-processes that influence those observations. These relations are used to handle semantic heterogeneities that impede the integration of geo-sensor data. Our approach comprises a process-centric hydrology ontology and its alignment with the DOLCE foundational ontology. We describe how DOLCE assists in classifying two hydrological processes and their participating entities. Our preliminary results indicate that the process-centric ontological approach can be used to resolve process and property naming ambiguity within a domain. We consider this as a first step toward a process-centric semantic integration of geo-sensor data. Keywords. Semantic heterogeneities, sensor data, ontology, surface hydrological processes, DOLCE