Evapotranspiration Calculation on the Basis of the Riparian Zone Water Balance

Abstract

Riparian forests have a strong influence on groundwater levels and groundwater sustained stream baseflow. An empirical and a hydraulic version of a new method were developed to calculate evapotranspiration values from riparian zone groundwater levels. The new technique was tested on the hydrometeorological data set of the Hidegvíz Valley (located in Sopron Hills at the eastern foothills of the Alps) experimental catchment. Evapotranspiration values of this new method were compared to the Penman-Monteith evapotranspiration values on a half hourly scale and to the White method evapotranspiration values on a daily scale. Sensitivity analysis showed that the more reliable hydraulic version of our ET estimation technique is most sensitive (i.e., linearly) to the values of the saturated hydraulic conductivity and specific yield taken from the riparian zone.