Author(s): Tran Kim Chau; William Veale; Nigel Connell; Hoang Thanh Tung; Nguyen Hoang Son
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Keywords: Surface water hydrology; PMP; PMF; Rainfall-runoff model; Dam safety
Abstract: The Dam and Downstream Community Safety Initiative (DDCSI) is a three year project with the objective of improving dam safety in Vietnam. As part of this project, the probable maximum flood (PMF) has been derived for two large dams with potentially high downstream impacts in the Nghe An province of Vietnam. Typically, the probable maximum precipitation (PMP) is used for the derivation of the PMF. In this study, the value of PMP for the two dam watersheds is determined using the Herschfield’s statistical method (WMO, 2009) and compared with the maximization of actual storms method (Kh? i&Ruan, 2009). Both methods used meteorological data from three stations, located in the research area. The estimated PMP was then used to compute the PMF at the two dam sites using a HEC-HMS rainfall-runoff model. The rainfall-runoff model was calibrated against historic storm events and showed good agreement between the predicted and observed data. The PMF discharge hydrographs resulting from the rainfall-runoff model will be subsequently used for assessing spillway capacity and for rainy day dam break flood inundation modelling.
Year: 2014