Estimating Salt Loads in High Water Table Areas. I: Identifying Processes

Abstract

This paper describes the detailed investigation on a 9 ha irrigated site with high water tables in the Tragowel Plains (Australia) of salt transport processes from shallow ground water to surface drainage. An intensive field monitoring program was established to record surface runoff and drain stage, fluctuations in water table levels, changes in the soil moisture profile, climatic data for estimation of evapotranspiration, changes in vegetation cover, rainfall and irrigation intensities, and field and laboratory measurements of a range of soil properties. The distributed, physically based European Hydrological System model was used to represent the processes using the field characteristics obtained for input parameters as well as time series flow and level data for calibration. Despite several limitations of the model, the significant physical processes occurring, and the range of their relative contributions of salt load to the surface drainage, were identified.