Principle:

The groundwater lysimeter represents a system, which is final at the side edges and which stands in connection with its environment over the upper and the lower edge. The lower edge is characterized by the groundwater inflow and groundwater discharge Rzu and Rab and/or possesses in periods of low ground water level a free discharge, comparably a gravitation lysimeter. At the upper edge the system stands in connection with the atmosphere over precipitation P, evaporation ET and over back-up Pond.  Due to the water rivers at the upper and lower edge the water content in the lysimeter changes, expressed as memory capacity ∆S. The water supply equation for such a system reads:

P + Pond = ET + ( Rab – R zu)

The quantities P, ∆S, Rzu, Rab and Pond are instrumentation seized, whereby the current evaporation ET from the water supply equation can be computed.

Principal purposes: 

• Temporal dynamics of the groundwater formation particularly in alluvial soils 
• Influence of floodings on groundwater formation and of water and solute balance
• Misalignment and mobility of heavy metals, nutrients, pesticides and other pollutants by changing redox conditions