Nitrate groundwater pollution and aquifer vulnerability: the case of the Osona region

Nitrate groundwater pollution in the Osona region is a persistent and widespread problem. Nitrate concentrations are commonly above the drinking water threshold of 50 mg/L in wells and springs. ANOVA and logistic regression analyses showed that nitrate concentration is more dependent on land use tha...

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Detalhes bibliográficos
Autor: Boy Roura, Mercè
Formato: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2013
País:España
Recursos:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/124042
Acesso em linha:http://hdl.handle.net/10803/124042
Access Level:acceso abierto
Palavra-chave:Nitrate
Nitrat
Nitrato
Groundwater
Aigües subterrànies
Aguas subterráneas
Vulnerability
Vulnerabilitat
Vulnerabilidad
Water pollution
Contaminació de l'aigua
Contaminación del agua
Modeling
Modelatge
Modelado
Osona
504
55
574
Descrição
Resumo:Nitrate groundwater pollution in the Osona region is a persistent and widespread problem. Nitrate concentrations are commonly above the drinking water threshold of 50 mg/L in wells and springs. ANOVA and logistic regression analyses showed that nitrate concentration is more dependent on land use than on the geological setting of springs. Nitrate content presented stationary values in most of the springs over time, while discharge and electrical conductivity evolution depends on the geological setting and rainfall events. This is attributed to a homogenization of the subsurface processes that determine nitrate infiltration after decades of intensive fertilization. A multiple linear regression model to assess groundwater vulnerability determined that the factors that significantly influence nitrate pollution are: nitrogen load, aquifer type, presence of well-drained and deep soils, irrigation and occurrence of denitrification processes. Vulnerability maps for unconfined, leaky and confined aquifers were developed and can be used for improving groundwater resources management