| Fresh groundwater in coastal areas throughout the world is a popular water resource for domestic, agricultural and industrial activities due to the availability of huge quantities and its high quality relative to surface water. For the future, the use of fresh groundwater resources is very likely to increase due to population rise (especially in megacities), economic growth, intensified agricultural development, and the loss of surface water due to contamination. The negative effects of salinisation is detected in the exploitation of groundwater for drinking water purposes and groundwater for agricultural use and nature conservation. In addition, sea level rise and the associated changes in recharge and evapotranspiration pattern will intensity the pressure on this coastal groundwater.
...
Subsequently, 3D variable-density groundwater and coupled salt transport models use these salinity data to more accurately predict the possible effects of climate change, sea level rise and human activities on the availability of fresh groundwater resources (Fig. 3). Adaptive strategies will be more effective (and cheaper) to limit the impact of negative future stresses. We think that incorporating all these different (innovative) techniques will, in the end, lead to a more sustainable water management.
| !percelen.jpg|width=500! |
Fig. 1 The device, 'the HEM bird of BGR', to retrieve the resistivity of the subsoil
Fig. 2 Helicopter borne geophysical systems: a. left: BGR system recording simultaneously frequency-domain electromagnetic, magnetic and radiometric data, b. right: SkyTEM system recording time domain electromagnetic data.
Fig. 3 It is very suspicious but here we think we have a perfect fit between different types of geophysical techniques (TEC, CVES, EM31), samples groundwater, Helicopter EM (conductivity at 4 m below sea level) and a 3D numerical model: the thickness of a thin fresh water lens largely varies over small distances
Information: gualbert.oudeessink@deltares.nl, perry.delouw@deltares.nl or jan.gunnink@tno.nl