A study of changes in the development level of water and sewerage infrastructure and environmental protection in the counties of the Silesian Voivodship – a dynamic interpretation

In this paper the author presents an analysis of the development of the water and sewerage infrastructure and environmental protection in the counties of the Silesian voivodship on the basis of designated synthetic variables in the dynamic approach. Selected years before and after joining the European Union are considered and some interpretative hypotheses are verified by empirical research. To achieve this purpose, the problem of the selection of diagnostic variables and the descriptive characteristics to be used, as well as the determination of the of the synthetic variables values based on selected aggregation formulas, also in dynamic terms, are discussed and suitable solutions are proposed.