A soil-water flux sensor and its use for field studies of transfer processes in surface soil

A soil-water flux sensor was developed, which determines the flux value from the difference between downstream and upstream temperatures at some distances from an artificial heat source. It can detect flux values ranging from several mm hr.^?1 to as small as 0.01 mm hr.^?1. Design and calibration of the sensor are described.

The sensor was applied to the field studies of transfer processes in a surface soil, including rainwater infiltration, upward soil-water flow during evapotranspiration, and their effects on the water table level. Cl^? accumulation in the surface soil is discussed on the basis of upward water flux and Cl^? content observed.