DAILY ACTUAL EVAPOTRANSPIRATION MEASURED WITH TDR TECHNIQUE IN MEDITERRANEAN CONDITIONS

This paper proposes to evaluate the performances of the TDR (Time Doma in Reflectometry) technique in a semi-arid region. To achieve this obj ective a comparison was made on a daily scale for sorghum and maize cr ops. Their actual evapotranspiration (ET) was measured by two independ ent methods: soil water balance budget, using soil water content measu red by gravimetric and TDR methods and energy balance equation (Bowen ratio). The daily ET values derived from soil water balance budget agr eed with the values of ET determined by the Bowen ratio. Results show that in soils without vertical cracks daily ET can be estimated in fie ld by using the TDR technique over a wide range of soil water content. (C) 1998 Elsevier Science B.V.