Developing a design rainfall intensity equation using measurement data from the Ha Dong meteorological station in Hanoi, Vietnam

In the design and calculation of stormwater drainage systems, the design rainfall intensity plays a crucial role and is widely used in runoff calculations. Due to the influence of local climatic factors, the selection of probability distributions for rainfall frequency analysis and the methods used to determine parameters for empirical equations result in a variety of equations compared to traditional Rainfall Intensity-Duration-Frequency curves. This paper focuses on developing a design rainfall intensity equation based on observed rainfall data from the Ha Dong meteorological station in Hanoi. The Generalized reduced gradient nonlinear method was applied to derive the equation. The results indicate that the proposed equation aligns more closely with Rainfall IntensityDuration-Frequency curves. The methods introduced in this paper can be effectively applied to develop design rainfall intensity equations for other urban areas, providing valuable support for the design of urban stormwater drainage systems.