A method for quantifying the effects of groundwater shortages on aquatic and wet ecosystems

This paper describes a method for quantifying the effects of groundwater shortages or parching on aquatic and wet ecosystems. Linear relations are determined between hydrological indicators and the degree to which ecosystems are parched. The degree of parching is expressed as a number between 0 (not affected) and 1 (fully affected). The method takes into account the following processes: lowering of water tables, decreasing intensity of upward seepage, increasing water table fluctuations and inflow of allochthonous surface water. It enables the degree of parching to be determined annually. The method was developed by the TNO Institute of Applied Geoscience and the Centre of Environmental Studies Leiden at the request of the Dutch government, which wishes to evaluate the effect of its environmental policy annually. It can also be used to monitor nature reserves on a local scale.