Groundwater investigations in Lower Kelantan River's Basin, Malaysia, using environmental isotope, Pt. 1

Variation in the stable isotopes and tritium compositions of water were used to define the mechanism of recharge to the groundwater system in the Lower Kelantan River Basin, Malaysia. The isotopic data demonstrate that the first aquifer is recharged either by precipitation and/or river water and in some places by the second and third aquifers. Recharged of the second aquifer seems to be from the first and third aquifers. Whilst the recharge mechanism of the third aquifer is still unable to establish with the present data, a more detailed investigation is needed. Tritium data confirm that all groundwater samples of the third aquifer are older than 25 years and most waters from the first and second aquifers are recent (<25 years). (author)