ISARM framework document (UNESCO, 2001) distinguishes five aspects of the transboundary aquifers, namely hydrogeological, legal, socio-economical, institutional and environmental. The original ISARM division is preserved here, although the practice has showed a strong interconnection among some aspects, making it difficult to study and address them separately. Besides, the practice showed quite diverse level of attention paid to various faces of transboundary aquifers.
Numerous activities (particularly GEF projects and ISARM inventories) conducted in the last couple of years have yielded precious information on particularly hydrogeological and institutional aspects of transboundary aquifers. Yet, this information has still tot be systematised, lesson learnt extracted and disseminated in a most adequate form.
The only substantial progress in structuring the knowledge has been made regarding the legal issue (by drafting the articles on the law of transboundary aquifers). Environmental aspect has been usually mentioned only in combination with other issues such as sustainable use of non-renewed resources and the climate variations.
Recently IGRAC produced an updated version of a Transboundary Map of the World. The back of the map contains an introduction to a methodology for assessment of TBAs.