Combined Sewer Overflow Emissions Modeling for the Sewer Catchment Area Graz-West

The aim of this diploma thesis is the modelling and calibration of a CSO of the sewer-catchment area Graz-West. After the calibration a long-time simulation was calculated with long-time precipitation series. With the long-time simulation and its analysis the influences of the different input parameters on the result were shown. The influence of the minimum discharge rate in accordance with the Austrian draft of stormwater regulation was analysed too. The CSO was modelled with the software KOSIM. The input data are from the sewer-online-monitoring-station Graz. The main problem of the modelling was the right reproduction of the spillflow behaviour of the CSO. The verification of the model was realized by means of a three months period. The long-time simulation showed results in a wide range compared each single year. The minimum values of discharge referred to the AEV Mischwasser draft could be kept. Analysis resulted paved area, end run off coefficient and rain weather concentrations as main influence factors. Therefore, these input values have to be determined exactly.