In the EcoTools and Wesp projects, concepts and software tools have been developed in the past that provide frameworks and tools based on individual-oriented techniques in order to create or use complex simulation models in a simple, application-oriented and targeted manner. These models can be used, among other things, to simulate complex individual-individual or individual-environment interactions within simulation programmes, to explore them and, by conducting simulation experiments, to better understand them. In this way, causal relationships between environmental situations (or environmental scenarios) and any extreme states of the population under consideration can be worked out in detail. Furthermore, the effectiveness of a specific management goal and the efficiency of planned system interventions can be estimated or verified in such simulation studies.

The populations considered in the context of this work were each made up of a few animals of one species, with the estimation of the survival time of these populations representing the central object of investigation. In supplementary studies, the use of these techniques in the field of environmental epidemiology was motivated and concretised within a concept (Köster and Sonnenschein 1998; Köster and Sonnenschein 1999).

In order to be able to make reliable statements about epidemiological phenomena by means of simulation studies, it is necessary that the real system and its modelling correspond with regard to their structure, i.e. the essential system or model components and existing or suspected cause-effect relationships, but also their quantitative characteristics. In concrete terms, this means that in epidemiological simulation studies it is essential to include real data on the environment, e.g. geographical information, as well as validated, existing simulators in the simulation (Köster and Sonnenschein 1999), in addition to information on the condition of the individual members of the study population, in order to possibly generate or process such data (in the sense of special interpolation by simulators).

The provision of a technical infrastructure to realise this coupling is the subject of the SimGis project, which supplements the corresponding interfaces within the EcoSim framework developed primarily in the EcoTools project (here the EcoSim sub-project).

In order to further increase the relevance of individual-oriented simulation techniques for environmental epidemiological problems, the integration of environmental data from geographic information systems (GIS) and the integration of external simulators (e.g. for the calculation of pollutant dispersion models or similar individual aspects) in individual-oriented models and simulators is of major importance, because:

• By integrating data from a GIS, the equivalence of a simulation to the real system can be strengthened if these data are used as "binding support points" of a simulatively determined time series.
• Compared to the time scale of the individual-oriented simulation models, the data within a GIS is usually very coarsely resolved in terms of time (recorded at intervals of months or years). Through the individual-oriented models themselves, but especially through the integration of external simulators, the data can be raised to the level of the high-resolution individual-oriented models (model states can be differentiated for days or hours) by interpolation between the grid points specified by the GIS.

The objectives of this project are therefore to

1. Integration of data stored in geoinformation systems about the real system into the simulation.
2. Integration of external simulators to increase the resolution of the real data with regard to their time resolution.
3. Integration with existing software systems

The main tasks required to achieve these goals are the integration of existing software and the support of widely used interfaces to GIS and simulation tools. The following figure shows the schematic of an integrated system consisting of centralised, individual-oriented simulation, external databases (GIS and virtual GIS) and external simulators, which uses intranet/internet connections to be distributed to different computers: The C++ framework EcoSim provides comprehensive support for the free implementation of independent individual-oriented simulation models in the universal programming language C++ and forms the basis of the project presented here. EcoSim simplifies the programming of the static and dynamic aspects of individuals and the environmental systems under consideration. Furthermore, the visualisation and simple aggregation of simulation data is supported, so that users can create independent individual-oriented simulation programs relatively easily. This framework is now being extended with regard to the missing interfaces to GIS and external simulators. In the context considered here, the Application Programming Interface (API) realised as part of the OFFIS project InterGis is relevant. This allows data from GIS to be integrated into various applications via the Internet/Intranet. The realisation is also so efficient that coupling with individual-oriented simulation models such as EcoSim is possible. Furthermore, a distributed database system can be realised via this, in which in particular the storage of simulation data can also be made possible.