Tracing methodologies used to estimate the impact of industrial and agricultural activities on surface and underground waters

The aims of this research are: - developing new methodologies and working techniques using artificial tracers to determine the flows in tubes, canals and rivers and the hydrodynamic parameters for underground water pollution; - studies of system transfer functions and development of mathematical models. These researches have resulted in the following conclusions: a) The pollution study of hydrological and hydrogeological systems using radioactive tracers can be performed using physical and mathematical models. b) On the basis of the relations established between the tracer specific amount at injection and output measuring point and using adequate flowing models, the desired information about the system can be obtained. c) When studying the pollution of an aquifer system with scarce experimental data, it is possible to use an empirical model which does not necessarily have a physical meaning. When certain parameters of the system are determined, the used model is a conceptual one and it must have a physical meaning. (authors)