Impact of hydrological changes on nature conservation areas in the Netherlands

The extraction of groundwater and the drainage of agricultural land can have an effect on nature conservation areas through the lowering of the phreatic groundwater level, the reduction in upward seepage and the inlet of surface water of poor quality, necessary to compensate for groundwater shortages. We made a nationwide assessment of the problem by conducting a survey of the resulting changes in vegetation. On the basis of this survey we concluded that at least 50% of the groundwater-dependent ecosystems in the Netherlands have been moderately to strongly affected by hydrological changes. Copyright (C) 1996 Elsevier Science Limited.