Advances In Out Door Lysimeter Techniques

摘要

Different methods exist for measuring soil water and solute fluxes in and below the root zone and have been critically reviewed.Besides indirect methods (e.g.water balance,tensiometer,time domain reflec-tometry - TDR,frequency domain reflectometry -FDR,environmental tracer) direct methods (e.g.drainage-type lysimeter,water fluxmeter) have a long tradition and have been successfully used in seepage research.A large weighable out door lysimeter is the best method for obtaining reliable data about seepage water quantity and quality,but it involves significant investment and additional expenses for maintenance.To tackle this problem new methods for the vertical collection of large volume soil monoliths (up to 6 m3) as well as for the horizontal collection (up to 6 m3) have been developed.For the placement of the lysimeter a container lysimeter unit was constructed,which is cheaper than a conventional steel or concrete cellar.Furthermore,the technical design of the newly developed lysimeter types as a weighable gravitation lysimeter,a weighable groundwater lysimeter and a lateral flow lysimeter are presented.