Application of tracer techniques in measuring flow parameters of ground waters

Radionuclides are used in single-bore and multi-bore methods. Measurements include the dilution of the radioactive tracer, its vertical movement, flow direction, and also actual flow rate of water, effective porosities of materials and dispersion coefficients helping to model the spread of material in field conditions. Artificial radioactive tracers have several advantages: they do not affect the physical and chemical properties of the water and the environment, and their specific activity may be easily and accurately measured. The measurement methods and instruments are described as are the formulas used for calculating the flow parameters. The described methods have been used in many localities. (M.D.)