Soil hydrology and EMI
Land conversion and the water balance
Conversion of boreal forest into agricultural land is likely to occur due to the shift of climatic zones and increasing food demand. However, any land conversion will affect the water balance – and hence solute fluxes within the soil column and connected ecosystems. Understanding the consequences of land conversion on soil hydrology is essential to support an economically viable agriculture while minimizing its environmental footprint.
What the simulations show
- Unconverted soils have lower saturation and higher infiltration rates, indicating lower runoff and increased infiltration and deep percolation.
- Agricultural soils have slower infiltration rates, particularly in the upper horizon.
- Over the long term, agricultural conversion increases erosion risk and nutrient loss by runoff.
- This may progressively limit groundwater recharge, affect hydrological processes and functions, and shape future drought and flood conditions at catchment levels.
Electromagnetic induction (EMI)
EMI is a non-invasive geophysical method to map near-subsurface features in engineering and environmental science. The working principle is based on a two-coil system that generates a primary magnetic field and induces eddy currents in the soil, creating a secondary magnetic field. The ratio between the two magnetic fields can be related to the electrical conductivity (EC) of the subsurface. Because EMI records integral EC values over a certain depth, its unit is called apparent EC (ECa). The ease of use and the wide range of possible applications have made EMI very attractive – see an example here →