Deriving of Intensity–Duration–Frequency (IDF) curves for precipitation at Hanoi, Vietnam

Abstract

The rainfall Intensity-Duration-Frequency (IDF) relationship is one of the most commonly used tools in establishing rain intensity formulas for urban stormwater drainage design. Currently, the rain formulas being applied in Vietnam according to the design standard TCVN 7957-2008 are mostly Soviet formulas with climate parameters dating back to the 80s of the twentieth century. Therefore, it is no longer suitable for the calculation of the current stormwater drainage system, especially in the context of climate change. In this paper, we used statistical methods to process rain gauge data from 1960 to 2021 to build the IDF curve for the inner city of Hanoi (Vietnam). The results show that the new IDF curves are more suitable for the current climate situation than the IDF curves according to TCVN 7957-2008.