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Isotopic Age and Composition of Stream Flow as Indicators of Groundwater Sustainability
Closed for proposals
Project Type
Project Code
F33015CRP
1333Approved Date
Status
Start Date
Expected End Date
Completed Date
12 May 2011Description
This project will develop and test an isotopic methodology for characterizing aquifers and catchments by monitoring baseflow age in large rivers as a tool for assessment of groundwater vulnerability. The baseflow in rivers maintains streamflow between water input events and can be derived from adjacent shallow aquifers, lakes and wetlands. The baseflow has been recognized as an important diagnostic variable for constraining global climate and hydrological models, but a gap remains on the issue how will changes in the baseflow impact the water availability and ecological stability in the catchments. Isotopic investigations of groundwater age have been proven as a tool for a better knowledge of the groundwater discharge into rivers from regional aquifers, lakes, wetlands and human settlements. The project will focus first on developing of methods in selected catchments with long available isotope records and test the ability of the methods to describe baseflow age distributions from small catchments to big river catchments. Then the age distributions of baseflow will be tested as resource management tools for assessment of changes and risks to water quality and quantity in large river catchments in Member States.
Objectives
To develop and test an isotopic methodology for characterizing aquifers and catchments by monitoring baseflow age in large rivers.
Specific objectives
To improve interpretation of baseflow as an indicator of shallow groundwater aquifers.
To investigate quantitative parameters responsible for shallow groundwater sustainability.
To study interactions between groundwater and surface waters on large river basin scale.
Impact
The CRP brought together investigators from different scientific backgrounds to assess the age and composition of groundwater sustainability in different geological and hydrological regimes. A combination of isotopic, geochemical, modelling and conventional techniques revealed the amount of groundwater flows into rivers and the temporal dimension of the travel time of groundwater from the infiltration areas to its discharge locations in streams. The CRP provided an opportunity to test various techniques of estimating age of groundwater as well as surface water for assessing the groundwater sustainability. This CRP revealed that Tritium dating may be a good tool for measuring baseflow residence time, but Tritium-Helium may be much better in cases where residence time is less. It is expected that the products of this CRP will serve as standard reference materials in an on-going studies of baseflow.
Relevance
The CRP is relevant for both IAEA and Target Countries, in particular for the following two reasons: a) assessment of travel time from aquifers to rivers reveals information about flow and storage of water and contaminants in a single characteristic, and therefore may be a fundamental integrated descriptor of aquifer/river sustainability, and b) isotope techniques are key research tool in estimation of travel time (“age”) of natural waters and therefore their application and further development provides significant advance in isotope hydrology.