7. Investigation of Transboundary Aquifers in Russia: Modern State and Main Tasks

Transboundary problems of groundwater development are very significant for Russia as it has land boundaries with 13 countries. The main research line concerning this problem is to develop principles and criteria of acceptable groundwater withdrawal by neighbouring countries with compliance with environmental limitations. This includes groundwater protection from depletion and contamination, development of constant groundwater deposit models applied in border regions of neighbouring countries in order to determine groundwater balance elements of certain hydrodynamic flows, their internal interaction and interaction with surface water. Estimation of potential groundwater shared use based on large scale assessment and mapping of its sustained yield with regard to groundwater protection from contamination is also of importance.

Determination of prospects for groundwater use and withdrawal management is always connected with the problems of exploitation restrictions in accordance with different criteria. The latter may be both internal and external. Among internal criteria are limitations of hydrogeological and hydrodynamic operation conditions, such as groundwater recharge rate, tolerance dynamic level lowering throughout estimated period, risk of non-standard groundwater being drawn up to a water intake, and others. The external criteria that can restrict groundwater use are related to possible impacts of a planned water extraction upon different environmental components including river run-off, suppression or death of vegetation due to excessive lowering of shallow groundwater level in the upper unconfined aquifer; activisation of karst and suffusion processes; earth surface subsidence, etc.

The main tasks of hydrogeological investigations are the following:

Specific examples of transboundary groundwater use perspective assessment in particular adjacent zone regions of Russia are presented.