Characterisation and visualisation of the subsurface
A clearer understanding of the structure and condition of the subsurface has a positive impact on sand extraction, water management and the search for alternative energy sources. Deltares develops and applies a range of measurement methods and software to explore the subsurface. We lead the quest for innovative solutions for a wide range of subsurface challenges facing society. Our advice is grounded firmly in state-of-the-art field measurements, equipment and methods, laboratory tests and computer models.
Innovative measurement methods
Deltares is active in various consortiums and partnerships with the aim of developing innovative measurement methods. For instance, in the Dutch province of Zeeland, the FRESHEM project is using an electromagnetic system to map out the boundaries of salt and fresh water in the subsurface from a helicopter. The results can be used to optimise freshwater management. Furthermore, technology is being developed that will make it possible to use satellite images to determine soil moisture levels. This is important in the area of soil and water management, for example in terms of calculating how much groundwater can be extracted from the subsurface without impoverishing the soil.
Deltares is active in a range of consortiums and partnerships with the aim of developing innovative measurement methods. For instance, in the Dutch province of Zeeland, the FRESHEM project is using an electromagnetic system mounted on a helicopter to map the transitions from salt to fresh water in the subsurface. The results can be used to optimise freshwater management. Furthermore, technology is being developed that will enable the utilisation of satellite images to determine soil moisture levels. This is important in the area of soil and water management, for example assessments of the potential for groundwater extraction potential.
A description of the subsurface is also fundamental for sand and water extraction. Deltares uses a combination of geophysical methods to characterize the subsurface, both on land and at sea. Those methods include seismics, sonar, electrical resistance and software for the analysis of Scholte waves on the seabed (MASW). For example this allows determining how much sand can be taken from the sea and how the seabed will recover afterwards. It is also possible to identify sand layers in desert regions from which fresh water can be extracted.
In the picture
Sharing the knowledge of the subsurface for a more efficient use of it is one of Deltares goals. By developing publically available apps Deltares aims at developing a deeper and wider public awareness about the ground layers below our feet and about the geological events of our past. Deltares PaleoMaps represents a beautiful example. This app enables to browse a time series of maps of the Netherlands, showing what the country once looked like from 5500 years before present to present-day land reclamation. These maps were a joint effort of Deltares (department of Applied Geology and Geophysics), RCE (Netherlands’ cultural heritage agency) and TNO Geological Survey of the Netherlands.
Stratigraphic modeling of river deltas
Characterizing the subsurface at great depth involves dealing with large uncertainties, as the data available, such as seismics and boreholes, are costly and limited. There is a need for better constraining geological properties, such as porosity and permeability, in order to use the subsurface more efficiently, e.g. for hydrocarbon or deep groundwater exploration. Through a continuous line of research Deltares, Dutch universities and industry partners have developed modeling techniques for building high-resolution geological models using Delft3D. Delft3D is Deltares process-based software, simulating water, sediment transport and morphological changes in river deltas. These techniques have been used to better understand how river deltas react to changing forcing, such as waves, tides, river discharge, and will be used by the industry to better characterize the variability of geological properties in the subsurface.