Design Storm for Mixed Urban and Agricultural Drainage Systems in the Northern Delta in Vietnam

A design storm definition procedure for the sizing of channels within mixed urban and lowland rice drainage systems is developed, with reference to the Northern Delta in Vietnam. By analyzing a 20-years-long time series of rainfall observations recorded at Hanoi monitoring station, typical storm events were identified and a set of suitable design storms was determined and recommended for the optimal design storm selection. A procedure to select an optimal design hyetograph is then defined, based on a combination of the design storm method and continuous simulation. A set of simulation experiments on a fictitious basin was finally carried out to support the choice of the storm temporal pattern providing the best performance in terms of reproduction of runoff peaks.