Author(s): Phuong Cu Thi; James E Ball
Linked Author(s): James Ball
Keywords: Flood flow; Hydrology; Flood frequency analysis; Continuous simulation
Abstract: Estimation of design flood flow has been a concern for many years in both hydrologic research and in hydrologic practice. Design floods provide a basis for sustainable flood management which has the aims of reducing flood risk, and protecting people’s lives and property. Design floods for a given location can be estimated by a number of approaches including analysis of past flood statistics or the use of catchment modelling approaches like design storm methods or continuous simulation. The aim of this paper is to contribute to the use of continuous simulation for the purpose of design flood estimation with particular reference to a monsoon catchment. For this purpose, a case study is performed for a large catchment, namely the Ba River, located in central Vietnam. This catchment is subject to a monsoonal climate and also to tropical cyclones. Three aspects of the study are highlighted with these aspects being: development of a gridded rainfall at an hourly through application of a disaggregation method, application of a continuous loss model, and the use of a non-linear transform method. Also highlighted is the calibration process where the annual maximum series was used as a performance measure rather than reproduction of individual hydrographs. This approach was used as the focus was on reproducing the observed frequency curve.