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

• Autores: Mercè Boy Roura
• Directores de la Tesis: Anna Menció i Domingo (dir. tes.), Josep Mas Pla (dir. tes.)
• Lectura: En la Universitat de Girona ( España ) en 2013
• Idioma: inglés
• Tribunal Calificador de la Tesis: Albert Soler i Gil (presid.), Elisa Sacchi (secret.), Bernard Thomas Nolan (voc.)
• Materias:
  • Ciencias de la tierra y del espacio
    • Hidrología
      • Aguas subterráneas
      • Calidad de las aguas
  • Ciencias tecnológicas
    • Ingeniería y tecnología del medio ambiente
      • Control de la contaminación del agua
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • 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