Application of isotopic tools to understand the hydrological processes and groundwater dynamics of Mianwali area-Punjab, Pakistan

Abstract

Abstract The study was conducted to investigate the hydrological system of ‘Mianwali’ area, which comprises an alluvium aquifer. Groundwater dynamics including groundwater direction, velocity and recharge mechanism were investigated to assess the groundwater sources conservation in the area. Hydrological samples were collected and analyzed for stable isotopes (18O and 2H); radioisotopes (3H), chloroflourocarbons (CFCs) and groundwater real and filtration velocities measured to understand the groundwater dynamics. Isotopic data suggested a variant recharge mechanism due to localize impacts of canals, lake and river. Groundwater residence time, using Tracer Lump Parameter Model (LPM), and CFCs data suggest a very young water in the range of 14–59 years old. The real and filtration velocities of groundwater found to be 22.2 cm/day and 10.94 cm/day, respectively, in south-west direction and in-situ effective porosity of the aquifer was 49.3%. The hydraulic conductivity of the aquifer was estimated using grain size analysis that varies from 48 to 278 m/day with average value of 139 m/day.