Tags

Type your tag names separated by a space and hit enter

Regional transport modelling for nitrate trend assessment and forecasting in a chalk aquifer.
J Contam Hydrol. 2010 Oct 21; 118(1-2):79-93.JC

Abstract

Regional degradation of groundwater resources by nitrate has become one of the main challenges for water managers worldwide. Regulations have been defined to reverse observed nitrate trends in groundwater bodies, such as the Water Framework Directive and the Groundwater Daughter Directive in the European Union. In such a context, one of the main challenges remains to develop efficient approaches for groundwater quality assessment at regional scale, including quantitative numerical modelling, as a decision support for groundwater management. A new approach combining the use of environmental tracers and the innovative 'Hybrid Finite Element Mixing Cell' (HFEMC) modelling technique is developed to study and forecast the groundwater quality at the regional scale, with an application to a regional chalk aquifer in the Geer basin in Belgium. Tritium data and nitrate time series are used to produce a conceptual model for regional groundwater flow and contaminant transport in the combined unsaturated and saturated zones of the chalk aquifer. This shows that the spatial distribution of the contamination in the Geer basin is essentially linked to the hydrodynamic conditions prevailing in the basin, more precisely to groundwater age and mixing and not to the spatial patterns of land use or local hydrodispersive processes. A three-dimensional regional scale groundwater flow and solute transport model is developed. It is able to reproduce the spatial patterns of tritium and nitrate and the observed nitrate trends in the chalk aquifer and it is used to predict the evolution of nitrate concentrations in the basin. The modelling application shows that the global inertia of groundwater quality is strong in the basin and trend reversal is not expected to occur before the 2015 deadline fixed by the European Water Framework Directive. The expected time required for trend reversal ranges between 5 and more than 50 years, depending on the location in the basin and the expected reduction in nitrate application. To reach a good chemical status, nitrate concentrations in the infiltrating water should be reduced as soon as possible below 50mg/l; however, even in that case, more than 50 years is needed to fully reverse upward trends.

Authors+Show Affiliations

Group of Hydrogeology and Environmental Geology, Geo³, ArGEnCo, Aquapole, University of Liège, Building B52/3, B-4000 Liège, Belgium.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

20864207

Citation

Orban, Philippe, et al. "Regional Transport Modelling for Nitrate Trend Assessment and Forecasting in a Chalk Aquifer." Journal of Contaminant Hydrology, vol. 118, no. 1-2, 2010, pp. 79-93.
Orban P, Brouyère S, Batlle-Aguilar J, et al. Regional transport modelling for nitrate trend assessment and forecasting in a chalk aquifer. J Contam Hydrol. 2010;118(1-2):79-93.
Orban, P., Brouyère, S., Batlle-Aguilar, J., Couturier, J., Goderniaux, P., Leroy, M., Maloszewski, P., & Dassargues, A. (2010). Regional transport modelling for nitrate trend assessment and forecasting in a chalk aquifer. Journal of Contaminant Hydrology, 118(1-2), 79-93. https://doi.org/10.1016/j.jconhyd.2010.08.008
Orban P, et al. Regional Transport Modelling for Nitrate Trend Assessment and Forecasting in a Chalk Aquifer. J Contam Hydrol. 2010 Oct 21;118(1-2):79-93. PubMed PMID: 20864207.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Regional transport modelling for nitrate trend assessment and forecasting in a chalk aquifer. AU - Orban,Philippe, AU - Brouyère,Serge, AU - Batlle-Aguilar,Jordi, AU - Couturier,Julie, AU - Goderniaux,Pascal, AU - Leroy,Mathieu, AU - Maloszewski,Piotr, AU - Dassargues,Alain, Y1 - 2010/08/31/ PY - 2010/03/23/received PY - 2010/08/13/revised PY - 2010/08/18/accepted PY - 2010/9/25/entrez PY - 2010/9/25/pubmed PY - 2011/2/2/medline SP - 79 EP - 93 JF - Journal of contaminant hydrology JO - J Contam Hydrol VL - 118 IS - 1-2 N2 - Regional degradation of groundwater resources by nitrate has become one of the main challenges for water managers worldwide. Regulations have been defined to reverse observed nitrate trends in groundwater bodies, such as the Water Framework Directive and the Groundwater Daughter Directive in the European Union. In such a context, one of the main challenges remains to develop efficient approaches for groundwater quality assessment at regional scale, including quantitative numerical modelling, as a decision support for groundwater management. A new approach combining the use of environmental tracers and the innovative 'Hybrid Finite Element Mixing Cell' (HFEMC) modelling technique is developed to study and forecast the groundwater quality at the regional scale, with an application to a regional chalk aquifer in the Geer basin in Belgium. Tritium data and nitrate time series are used to produce a conceptual model for regional groundwater flow and contaminant transport in the combined unsaturated and saturated zones of the chalk aquifer. This shows that the spatial distribution of the contamination in the Geer basin is essentially linked to the hydrodynamic conditions prevailing in the basin, more precisely to groundwater age and mixing and not to the spatial patterns of land use or local hydrodispersive processes. A three-dimensional regional scale groundwater flow and solute transport model is developed. It is able to reproduce the spatial patterns of tritium and nitrate and the observed nitrate trends in the chalk aquifer and it is used to predict the evolution of nitrate concentrations in the basin. The modelling application shows that the global inertia of groundwater quality is strong in the basin and trend reversal is not expected to occur before the 2015 deadline fixed by the European Water Framework Directive. The expected time required for trend reversal ranges between 5 and more than 50 years, depending on the location in the basin and the expected reduction in nitrate application. To reach a good chemical status, nitrate concentrations in the infiltrating water should be reduced as soon as possible below 50mg/l; however, even in that case, more than 50 years is needed to fully reverse upward trends. SN - 1873-6009 UR - https://www.unboundmedicine.com/medline/citation/20864207/Regional_transport_modelling_for_nitrate_trend_assessment_and_forecasting_in_a_chalk_aquifer_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0169-7722(10)00104-X DB - PRIME DP - Unbound Medicine ER -