A comparison study between the joint probability approach and time series rainfall modelling in coastal detention pond analysis

In tidally affected coastal catchment s detention pond should be provided to store flood surface water. A comparison between the full simulation approach based on the joint probability method and time series rainfall modelling via the annual maximum of pond level was undertaken to investigate the assumptions of independence between variables that are necessary in the joint probability method. The rainfall data was run through a catchment model and the inflow hydro graph was obtained. This inflow was run through a detention pond with an out fall significantly affected by tidal action. The tidal variations were determined at that exact historical time of the time series rainfall. A continuous record of time series pond level was therefore determined and the peak pond level for each year was used to generate the annual maximum series of pond levels. As comparison between the growth curves of full simulation approach, and the time series rainfall modelling was undertaken. the results indicate that there are no significant differences between the two growth curves generated