Concentration transect
Mean measured concentration per well versus distance from coast. Toggle between Cl⁻ and EC. Bubble size reflects number of measurements.
Time series
Cl⁻ and EC over time for a selected well. Both tracers shown on independent axes to reveal divergences that indicate active cation exchange or non-seawater salinity sources.
Depth profiles
Concentration vs sampling depth for all wells in the selected year. Toggle tracer. Near-coast wells in red, mid-range in amber, distal in green.
Depth in metres below ground level. Inverted axis.
Cl⁻ vs EC cross-plot
Raw Cl⁻ vs EC for all matched observations. The dashed line shows the expected conservative mixing trend for Mediterranean seawater (Cl/EC ≈ 0.42). Points above the line have relatively more Cl than expected (freshening phase); points below indicate EC elevation from non-seawater sources.
Mediterranean seawater: Cl ≈ 19,800 mg/L, EC ≈ 47,000 µS/cm. Mixing line slope = 19800/47000 ≈ 0.42 mg·L⁻¹/µS·cm⁻¹.
Well locations
Monitoring wells coloured by mean Cl⁻ concentration. Click any marker for details.
ETRS89 UTM 31N → WGS84. Basemap: OpenStreetMap.
System comparison
Raw Cl⁻ and EC statistics for Ter vs Tordera. The Tordera is a much smaller delta system with correspondingly lower absolute concentrations.
Cl⁻ transect — both systems
EC transect — both systems
Ter max Cl (8,519 mg/L) is ~5× higher than Tordera max (1,734 mg/L), consistent with the larger delta extent and higher pumping pressure. Falgàs et al. (2011) report Cl values of 1,580–1,420 mg/L at 1–2 km inland in the Tordera deep aquifer, in agreement with observations here.