The basis for the design of the municipal network for rainfall runoff is reliable precipitation data for a sufficient period of time. With the analysis of rainfall data and the following runoff modelling, peak discharges for sewage network are calculated. The final product of statistical analysis of rainfall data are
IDF curves (intensity-duration-frequency) designed for a specific location. For the predetermined return period, using IDF curves, rainfall intensities can be obtained for different durations of rainfall event and vice versa.
Aim of the thesis is to determine the influence of aggregation of precipitation data on final results. IDF curves were made for ten different meteorological stations and two stations, which included combined precipitation data of three independent stations.
First part of the thesis contains a brief description of wastewater and rain water disposal and review of precipitation data analysis with emphasis on probabilistic approach. Since only the influential rainfall events are considered in the analysis, a threshold intensity or an alternative selection of rainfall data needs to be established and with the remaining data statistical analysis can be made.
Practical part describes probabilistic analysis and finding of a power curve to fit the calculated data. Also, through different statistical tests, impact of aggregated precipitation data on reliability of the final results was evaluated.