Abstract

Subsurface water assessment (moisture status) in unsaturated soils is one of the most important parameters that influences slope instability. Research on the spatial and temporal dynamics of soil water has long been impeded by the lack of an automated technique for the measurement of soil water content in the field. Automating soil water content measurements by time domain reflectometry (TDR) technique has become a very popular method and is widely used. Further development on the TDR technology can also be used for long term monitoring slope movement at potential landslide areas. The objective of this paper is to review methods and case studies of measuring subsurface moisture content conditions in soils and the use of coaxial cables in monitoring slope movement using TDR automatic data logging system. Some advantages and limitations of using TDR techniques in soil studies are highlighted.