Application of Thermocouple Psychrometers to Soil Water Transport

Abstract

The energy status (potential) of water can be used to calculate water flux. Thus, field measurement of water potential is superior to conventional gravimetric soil moisture content measurements for dynamic soil water studies and is useful for steady state analysis of soil water transport. Data presented show that soil thermocouple psychrometers give sufficiently sensitive, in situ measurements of water potential to apply energy concepts to dynamic soil water movement. Thus the soil thermocouple psychrometer can be used to obtain soil water potential information needed to determine the direction of water flow and the magnitude of the driving force. This technique is not limited to studies of the penetration of rainfall in the arid region but also has application in evapotranspiration studies, and might be adaptable to such studies as groundwater hazards of sanitary land fills.