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Publication
Assessing agriculture pollution in the Beja aquifer using nitrogen isotopes, South Portugal
Advisor(s)
Abstract(s)
This paper intent to give scientific support for political decisions, considering the sustainable development of rural regions under semiarid conditions exploiting shallow aquifers, and promote appropriate use of nitrogen fertilizers, based on EC Water Framework Directive and EC Groundwater Framework Directive in the context of vulnerable aquifers. Stable nitrogen isotopes (15N/14N ratios) can offer a direct way to identify the pollutant sources in groundwater systems. In the research area two major sources of nitrate were identified, fertilizer and manure, which present different isotopic d15N signatures. The relative contributions of these two sources to groundwater or surface water can be estimated by mass balance. The analysis of nitrate d18O together with d15N improves the ability to trace nitrate sources and cycling. According field practice in the rural area of Beja, major cause of pollution comes from fertilizers. Isotope results are not conclusive about the possibility that major source of nitrate-N in groundwater comes from agriculture as expected. Further work is required regarding seasonality sampling and laboratory techniques with sufficient precision accuracy.
Description
Keywords
Agricultura Desenvolvimento sustentável Poluição do solo Aquíferos Isótopos Sistema Aquífero dos Gabros de Beja (Portugal)
Citation
Paralta, Eduardo; Carreira, Paula M.; Ribeiro, L. Assessing agriculture pollution in the Beja aquifer using nitrogen isotopes, South Portugal. In: Actas de International Symposium on Advances in Isotope Hydrology and its Role in Sustainable Water Resources Management, Vienna, Austria, 21-25 May 2007