Hydrochemistry and stable isotopes revealed focused and diffuse recharge processes in the Sonora River basin, Mexico.

A hydro-geochemical characterization was conducted in the northern part of the Sonora River basin, covering an area of 9400 km. Equipotential lines indicated that groundwater circulation coincided with the surface water flow direction. Based on the groundwater temperature measured (on average ∼21 °C), only one spring exhibited thermalism (51 °C).