The article deals with the integration of information systems for emergency assistance decision support at the municipal level. There are different emergency services maintaining their own information systems with incompatible data structures. In many cases, information interchange for a coordinated response from more than one service is required. The article studies the problems of the integration of heterogeneous information systems with different architectures and database structures. The use of multidimensional and extended multidimensional objects for combined description of the databases with different structures is considered. Various integration schemes for different information systems are discussed. An example of the integration of information systems of emergency services of the city of Ufa is given.