Hydrogeology

I presently work as a hydrogeologist at DELTARES.
I find groundwater a fascinating resource, because it has a lot of potential while there is still a lot unknown about it.
Groundwater is a tremendously important resource in many parts of the world. Especially in Arid regions, groundwater is of major importance. In these regions fresh surface water sources and reservoirs are often lacking or fast drying up due to high evaporation. Groundwater resources are less prone to that, and are a more reliable water source. Surface water namely moves at very high speeds (metres per second), while groundwater only moves very slowly (metres per day).

Geochemistry

The slow movement through soils and rock cracks also filters the water, and adds minerals and other substances to the water. This may have a healthy effect, but it may also cause harmful substances to enter the water. Monitoring groundwater quality is therefore as important as monitoring the available groundwater quantitites (i.e. groundwater levels).
Being a geochemistry graduate, I naturally consider the chemistry of groundwater as very important.  However, since quantitative groundwater assessment is already such a daunting task, and because so much still remains to be done in the quantitative area, the chemical part is often underrepresented in assessments and management. Of course people are aware that pollution due to anthropogenic occurs and should be prevented, but pollution due to natural causes is often still less well understood. In addition to that, the threat of a biologic contamination also exists: bacteria may live in groundwater as deep as 1000nds of metres!
IGRAC made global probability assessments for fluoride or Arsenic contamination in groundwater around the world. I was involved in updating their findings through GIS analysis.

GIS/Geoweb

Much of the work I do consists of working with Geographic Information Systems (GIS) and doing GIS-analyses. This can help us to understand groundwater much better, but in addition to this, I believe modeling is also a valuable tool. Because of the hidden nature of groundwater, it is often difficult to measure or monitor changes in its availability and composition. Measurements often give very local information. To work on global scales, aggregation of information is therefore necessary, as well as using models.
To do effective GIS analysis and modeling, still a lot of data is needed. Global information sharing is therefore of major importance to a hydrogeologist. Major EU projects like GLOWASIS and DEWFORA try to promote open data sharing and accessibility to EO and RS data (Earth Observation and Remote Sensing).

The Geoweb is nowadays used to refer to geodata enabled websites and applications. This brings together two things I greatly enjoy: GIS and the internet.

Sustainable & Rural Development

I grew up in Western Africa, and because of that I am still fascinated with the arid regions on earth. As mentioned before, groundwater is of major importance to many people living in arid regions, because it is less prone to evaporation and seasonal fluctuations. The down side is, that in these regions groundwater is hardly recharged, and mining the fossil groundwater sources is thus an unsustainable practice in the long run. Water management in arid regions is always important, and groundwater is often the largest available fresh water source. Although managing it sustainably is virtually impossible, good management practices can reduce the adverse effects of overexploitation. There are a myriad of measures which can enhance groundwater recharge. They are collectively referred to as Managed Artificial Recharge (MAR). I worked on MAR with IGRAC in the 3R consortium.

The Millennium Development Goals
Groundwater plays an important role in the Millennium Development Goals (MDGs). Not only as a natural resource which should be managed wisely (point 8 ), but also because clean water availability may enhance children going to school, hygiene and health and other factors. People often forget that groundwater has a deep impact on socio-economic aspects of our societies, because these are not direct consequences of groundwater availability, but indirect consequences.