A Musacchio1, J Mas Pla2, Viviana Re3, E Soana4, E Sacchi1
1. Department of Earth and Environmental Sciences, University of Pavia
2. Catalan Institute for Water Research & University of Girona
3. Department of Earth Sciences, University of Pisa
4. Department of Life Sciences and Biotechnology, University of Ferrara
(a) Purpose or objectives and status of study or research hypothesis
Governance, as a proper process for water management, lays on multiple factors, sometimes impeding a fruitful debate within appropriate timeframes. Nitrate reduction in groundwater is one of the most challenging and long-term environmental issue faced by the EU. Groundwater governance in the Lombardy Plain (N Italy) include a tangled network of stakeholders dealing with conflicting socio-economic issues, in addition to environmental requirements. Moreover, the way that nitrate data are gathered and presented mainly involves just a trend analysis, which does not integrate the hydrodynamic behavior of the system. Under this partial information, it is hard to create a rich management context for reaching governance goals under changing hydrological conditions.
(b) Key issue(s) or problem(s) addressed
This paper addresses the information and capacity gaps, as described by the OECD, related to the achievement of adequate nitrate concentrations in aquifers by using groundwater flow and transport numerical models. The main point is that such models permit including all factors that will be potentially affected by climate change as model terms. In that way, backcasting simulations can illustrate the outcome of a given action.
(c) Methodology or approach used
Actual data from Lombardy Plain are used to model the hydrogeological system between Adda and Serio Rivers, over a 10-year period, to reproduce nitrate evolution. A water budget, including factors that depend on human decisions/needs as surface water irrigation and groundwater withdrawal, and a nitrogen budget were used to determine the appropriate initial and boundary conditions, and source/sink terms.
(d) Results and conclusions derived from the project
The numerical model successfully reproduces hydraulic head and nitrate concentration records obtained from government databases. As a result, the estimated terms of the water and nitrogen balances offer an objective portray of the system hydrodynamics. Therefore, any variability of the input terms will faithfully reproduce the outcome at a given time term, which provides the necessary support to evaluate whether human decisions will be successful under the present hydrological conditions or the new ones according to the climate change scenarios.
(e) Implications of the project relevant to selected conference theme, theory and/or practice
The research points out the versatility and reliability of these methods as an accurate support tool to deal with the complexity of groundwater governance. As shown, groundwater resilience under changing climatic conditions could be nicely simulated. This overcomes the common information and capacity gaps usually inherent to governance processes (and most evident
under changing conditions) as modelling results provide decisive information in the path to achieve the sustainability of natural resources; for instance, in the application of the EU Nitrate Directive.
Funding: INTEGRON project supported by the Cariplo Foundation (Grant number: 2015-0263), Spanish Research Program project PACE-IMPACT (FEDER-MCIU-AEI/CGL2017-87216-C4-4-R).