During the last decades, severe qualitative and quantitative imbalance is being detected for many important aquifer systems worldwide, even beyond the limits of sustainability, due to overexploitation and climate change. Among the most challenging topic, the increase of nitrate concentration in groundwater, especially in rural areas, is a matter of concern. More than 20 years after the issue of the EU Nitrates Directive, the spatial/temporal trend of nitrates in groundwater is still poorly understood. As argued within EU water-related Directives, ICT (Information and Communication Technology) may provide proper tools (e.g., numerical models and GIS (Geographic Information Systems)) to address integrated water resource management.
Efforts have been spent in this direction within the framework of the HORIZON 2020 FREEWAT project, whose main result is a composite QGIS plugin, the FREEWAT platform, which couples the power of GIS geo-processing tools for spatial data analysis with that of free and open source process-based simulation models (e.g., MODFLOW and other codes developed by the USGS) for the simulation of the hydrological cycle. Taking step from FREEWAT results, the general objective of the SMAQua project (SMArt ICT tools per l’utilizzo efficiente dell’AcQua - smart ICT tools for efficient water use) is to deal with water quality issues by means of smart software applications aimed, among the others, at reducing the impact of irrigated agriculture.
In order to fulfill the objectives of the Nitrates Directive, a tool for the simulation of the nitrogen cycle in the unsaturated zone has been integrated within the FREEWAT platform. The integration strategy consists in coupling vertical flow through the unsaturated zone and surface runoff, as simulated by MODFLOW, and all the processes involved in the nitrogen cycle, as simulated by the ANIMO (Agricultural Nutrient Model) model. The latter is a lumped code which simulates nutrients leaching to the water table, taking into account agricultural strategies, soil properties, land use and the hydrological conditions. The coupling approach consists in downscaling at the grid cell scale, all the processes simulated by ANIMO at the basin scale. As a result of the coupling methodology, the amount of nitrate which reaches the water table by percolation is estimated and treated by solute transport models (e.g., MT3DMS) for the simulation of advection-dispersion processes in groundwater.
The proposed solution is thought to provide innovative and digital tools for companies and water authority to evaluate the impacts of agricultural practices on water quality and to enhance agricultural water management.
The SMAQua project has been co-financed by Regione Toscana, ASA S.p.A. and ERM Italia S.p.A.
This paper provides exploitation of the H2020 FREEWAT project results. The FREEWAT project received funding from the European Union’s HORIZON 2020 research and innovation programme under Grant Agreement n. 642224.