Processing Multiple Databases in the Estonian Water Information System.

For the purpose of gathering and publishing Open Data, the Estonian Environmental Information Center (EEIC) has numerous databases of different architecture and structure available. An Estonian Water Information System (EWIS) is being planned and already being developed using these databases. Countries such as the USA and UK have already taken leaps to have their it available to the general public, and Estonia is following suit. In line with the Aarhus Convention (Aarhus, 1998), which states that environmental data, which is also considered to be Open Data, needs to be readily available to the general public. The main issues appearing with the data is that due to the structural differences, it is difficult to make the data contained in them interoperable in the EWIS. This issue will be tackled by a database interface, which will be designed for using the EEIC databases in co-operation, formatting the data on demand to a form which the EWIS will easily recognize and utilize within its applications. The information system itself will be used for providing public services, including simple queries about water condition, specific queries for water parameters, overview of the Estonian waters and modeling data to predict outcomes to an userdefined situation. Queries will be responded to in real-time, including those which need models to process data before returning it to the user. This means the EWIS will be a tool to be used widely, not limiting itself to Estonians, as foreigners might take an interest in the condition of Estonian waters as well. This also makes the EWIS a very suitable tool for environmental specialists from any country, such as hydrologists, to scrutinize Estonian watersheds, for example. In the future, it is a possibility that the EWIS will be integrated within the Estonian national data exchange grid, X-road (X-tee in Estonian), as a service. General information and appraisal will be offered, for people who are more interested in data on more of a black and white scale, meaning the system will estimate if something about a river or lake is either bad or good. In the future, the EWIS will be designed to offer these services from a cloud-based platform. These services will at the same time be offering Open Data to its users, as all environmental information is defined as such. Any sort of data processing applied by the EWIS will also be considered as Open Data, and no monetary compensation for the processing shall ever be asked from the end-user.