Using the SIMGRO regional hydrological model to evaluate salinity control measures in an irrigation area

In irrigated areas with drainage and an important interaction with the groundwater system, it is often difficult to predict effects of measures to control salinity. Therefore, in order to evaluate measures to control salinity the SIMGRO integrated regional hydrological model was extended with a module for conservative matter. This modified model was applied to an irrigated area of 2650 ha in the province of Mendoza, Argentina, after being calibrated with data on groundwater levels, evapotranspiration and salinity. The differences between calculated and observed salinity were generally small, except in the root zone, where observed values varied considerably in time and over short distances. Runs with four scenarios revealed that using more groundwater would be a very effective measure for controlling salinity. In subregions with shallow groundwater, improving the drainage system would also be beneficial and has the advantage that there is no risk of overexploiting the aquifers, which are a finite source of good quality water.