Assessment of SGD in karstic coastal massif : Aiguadolç beach (Garraf)
/ Pau Navarro Maestro, Dídac Navarro Fernández ; GeoWASU, grup de recerca ; [dirigit per: Jordi Garcia-Orellana, Mario Zarroca]Navarro Maestro, Pau
Dirigida per: Garcia-Orellana, Jordi; Zarroca, Mario. Universitat Autònoma de Barcelona. Facultat de Ciències, 2019
1 recurs electrònic
Premi UAB de la Fundació Autònoma Solidària (FAS) als millors Treballs de Fi de Grau sobre desenvolupament sostenible i justícia global. 3a Edició, curs 2018/2019.
Submarine groundwater discharge (SGD) is an important source of freshwater and nutrients to Mediterranean Sea, but is also related with anthropic pollution. Since the last decades a new emerging and successful ways to trace SGD appeared, as they are natural radioactive isotopes (223Ra, 224Ra, 226Ra, 228Ra and 222Rn) and electrical surveys (electrical resistivity tomography , ERT). Other methods have been less employed, but they have a great potential as electric induction (EI). This project describes and quantifies SGD and its nutrients driven input with these methods, never used before in Catalonia to asses SGD, in an anthropized coastal karstic massif. The study zone is Aiguadolç beach (Spain), the most southern beach in the Garraf massif, and the obtained SGD flows there were 9.7 ñ 2.0 ú10(6) m3-km-1-yr-1, with the associated fluxes of DSi, DIN and DIP, which were 63 ñ 13 mmolúm-2úd-1, 78 ñ 16 mmolúm-2úd-1, and 432 ñ 91 µmolúm-2úd-1, respectively. A NH4+ flux of 74 ñ 16 mmolúm-2-d-1 was also estimated due to high concentration of NH4+ in groundwater. This concentration exceeds the legal limits of drinking water legislation. This high contamination suggests an anthropogenic influence of the aquifer which could be due to waste water leaking from urban, agricultural or livestock activity or the Garraf landfill itself. The study also evaluates the social conflict framed in Aiguadolç due to some issues that affect the beach in relation with SGD and outlet emergences, and propose some management actions that could improve the situation.