• 2023-07-20

Restoring Dutch nature reserves

The Dutch government has identified a number of areas in which they want to asses and restore the landscape to a nature reserve. One of these projects was located in the stream valley of the Vledder Aa, a small river in the north of the Netherlands.  The project's objective was to map the subsurface geology as input for a geohydrological model and to unravel the original natural pathway of the stream that had undergone modifications over time due to human agricultural activities and environmental changes. The MS-2000 gamma-ray spectrometer was a crucial tool in characterizing the soil composition. 

The spectrometer provided valuable insights into the different geological layers and their distribution by analyzing the gamma-ray emissions of various soil types in the research area. The collected gamma-ray data allowed the identification of variations in soil composition and detected geological features, hidden from the naked eye, that indicated the stream's historical path. By comparing these findings with historical maps, geological data, and geomorphology, they began to piece together the course of the ancient stream, providing a solid foundation for their landscape remodeling endeavor. 

Quad measurement
Lutum content

The resulting radionuclide data was used to identify the lutum content of the area (particles < 2 µm), which clearly showed where old meanders were located (red color in the figure). Peat (with low lutum content) was accumulated in these old abandoned meanders The resulting data allowed landscape architects and environmental planners to work hand in hand, determining where the stream should be restored to its former route and how to design the landscape to mimic its original state best while considering the groundwater systems dictated by the soil composition. 
This project served as a testament to the gamma-ray spectrometer as a geophysical technique. It showcased how integrating historical research and cutting-edge technology could lead to thoughtful and sustainable landscape design and conservation efforts.