The time-domain reflectometry method for measuring soil water content and salinity

Abstract

This paper discusses the physical principles and use of time-domain reflectometry as a new tool for studying water and solute transport in unsaturated soils. In-situ measurements of water content and bulk soil electrical conductivity are shown to give results that are comparable with those obtained by conventional non-destructive techniques. An equation is presented that relates the bulk soil electrical conductivity to the soil solution electrical conductivity. Also derived are constraints that water content and electrical conductivity place on the use of time domain reflectometry sensors.