Use of relevant geo-information is one of the important issues for performing different tasks and processes in disaster response phase. In order to save time and cost, services could be employed for integrating and extracting relevant up-to-date geo-information. For this purpose, semantics of geo-information should be explicitly defined. This paper presents our initial results in applying an approach for semantic annotation of existing geo-datasets. In this research the process of injecting semantic descriptions into geodatasets (information integration) is called semantic annotation. A web system architecture is presented and the process of semantic annotation is presented by using the Meta-Annotation approach. The approach is elaborated by providing an example in disaster response which utilizes geo-datasets in CityGML format and further two languages of semantic web technology: RDF and Notation3.