Combined use of stable isotopes and hydrochemical characteristics to determine streamflow sources in the Jonkershoek catchment, South Africa.

The stable isotopes of water (O, H) and other hydrochemical properties were used to assess seasonal changes between sources of stream water and flow pathways in baseflow conditions for two headwater sub-catchments (∼3 km) of the Jonkershoek, a mountainous catchment in the Western Cape of South Africa. The sub-catchments differ in land cover, one is dominated by indigenous fynbos vegetation and the other by pine plantation. Stream water, higher elevation springs, and lower elevation groundwater samples were collected monthly from January 2018 to January 2019, and were analysed for stable isotopes, electrical conductivity (EC) and pH.