Synthetic Design Hydrographs Based on Distribution Functions with Finite Support

The primary characteristics that influence the potential of defining a synthetic design hydrograph (SDH), are the hydrograph shape, peak discharge (Qp), volume (V), and duration (D). This paper studies the advantages and shortcomings of using simple distribution functions with finite support (namely, beta and generalized standard two-sided power distributions) to represent and synthesize direct runoff hydrographs. The relationships among Qp, V, D, and distribution parameters are explored on a few flood events selected by a recursive digital filter algorithm and an overthreshold approach. The results obtained indicate that the adopted procedure provides a good compromise between simplicity and accuracy for building SDHs with two assigned flood characteristics (e.g., Qp and V) and a defined shape.