We, the National Centre for Environmental and Nature Conservation Information, develop the portal umwelt.info (https://umwelt.info/) which acts as a central access point to all of Germany’s knowledge on the environment and nature protection. We integrate all openly accessible sources from municipalities to federal states, civil society, economy and sciences into one flexible catalogue. We follow an agnostic approach and neither require nor enforce a specific technical standard to add data and information into our catalogue. This approach is inclusive, but due to the nature of this flexible catalogue no fixed metadata standard is preferred. Here, we want to present our approach on how to combine this diverse data ecosystem into one searchable catalogue. We develop an open-source software, where everybody can contribute to the development. Thus, we would like to give insights into our development process, how you can contribute, or give feedback on useful features. We offer a native API representing our own flexible metadata schema, as well as an emulated CKAN interface. Furthermore, we create editorials and download scripts that provide access to openly available data in Germany using our catalogue. These products aim to help scientists to gain easier access, as well as information on reusability. Our current product can be found at https://umwelt.info and our current development stage at https://gitlab.opencode.de/umwelt-info.
Berthold et al. (Thu,) studied this question.