Leaching of phosphorus (P) from agricultural land is an important source of eutrophication in the Bollenstreek in the Netherlands. This is because floriculture has led to high P concentrations in the sandy soils with low organic carbon content, which are characterised by a low retention capacity for P. In this study, P concentrations in groundwater from three plots in the Bollensteek were found to exceed the water framework directive (WFD) by a factor of 40. The case study on a single plot showed a phosphate load of 5.5 kg/ha/year leached through the tile drains, which is an order of magnitude higher than fields outside the Bollensteek. To understand where phosphate comes from and how hydrological processes influence leaching, hydraulic and chemical measurements of soil, groundwater and tile drain outflow were taken in a field with regulated tile drainage, and two hydrological models were created to simulate wet winter and dry summer conditions. The results showed the flow paths from this plot under wet and dry conditions and illustrated how hydrological processes can influence phosphate leaching through the soil and tile drains.

Due to climate change a rise in sea level is expected, which is a threat to the coastline of the Netherlands. The area of the project focuses on the seaside resort of Scheveningen, and specifically on the area from the Morales boulevard to the start of the natural dunes. The reason for this specific area is because the municipality of The Hague has little information about what the consequences are in this area due to future sea level rise. Furthermore, the Grand hotel Amrâth Kurhaus and different kind of hospitality industries are situated here. The Amrâth Kurhaus is a monumental building with a lot of history, therefore the municipality of The Hague attaches great value to it. However, whether future sea level rise will really cause for a hazard for the Amrâth Kurhaus and its surroundings is not clear. The first aim is to investigate whether this is the case or not. The second aim is to find how it could be solved if there is a problem.