Integrated Hydrological-Hydraulic Model for Flood Simulation in Tropical Urban Catchment

Hasrul Hazman Hasan,Siti Fatin Mohd Razali,Ahmad Zafuan Ibrahim Ahmad Zaki,Firdaus Mohamad Hamzah

doi:10.3390/su11236700

Hasrul Hazman Hasan, Siti Fatin Mohd Razali + Show 2 more

Open Access

https://doi.org/10.3390/su11236700

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Abstract

In recent decades, Malaysia has become one of the world’s most urbanized nations, causing severe flash flooding. Urbanization should meet the population’s needs by increasing the development of paved areas, which has significantly changed the catchment’s hydrological and hydraulic characteristics. Therefore, the frequency of flash flooding in Malaysia’s urban areas has grown year after year. Numerous techniques have been used, including the statistical approach, modeling, and storm design methods, in flood simulation. This research integrated hydrology and hydraulic models to simulate the urban flood events in the Aur River catchment. The primary objective is to determine water level and forecast peak flow based on hydrological assessment in the drainage system using XPSWMM software. The rainfall data for 60 min was used for this study in the hydrological analysis by obtaining an intensity-duration-frequency curve and peak flow value (Q peak). XPSWMM is used to simulate the response of a catchment to rainfall events in which runoff, water depth profile, and outflow hydrograph are obtained. Peak runoff is also obtained from the modified rational method for validation purposes. The proposed method was verified by comparing the result with the standard method. This is essential to identify flash flooding, which can lead to efficient flood mitigation planning and management in the urban catchment. The increase in residential areas results in the alteration of time of concentration, water quantity, and flow rate. Thus, to mitigate present and future problems, the effects of urbanization on water resources and flood should be analyzed.

Highlights

Flood is a frequent natural disaster and can cause adversity to the country and people
The effect of urbanization on local urban flooding is more important than climate change [4,5]
Urban flooding generally happens when heavy rainfall is immediately followed by a restricted drainage system capability [6]

Summary

Introduction

Flood is a frequent natural disaster and can cause adversity to the country and people. Urban flood is a complicated phenomenon owing to the inhomogeneity of the urban surface [1]. Over the past few decades, urban flood intensity has risen worldwide in response to two primary factors—urbanization and climate change [2,3]. The effect of urbanization on local urban flooding is more important than climate change [4,5]. Urban flooding generally happens when heavy rainfall is immediately followed by a restricted drainage system capability [6]. Depending on the drainage system, particular drainage layout features, and specific local limitations, flooding in the urban catchment may happen at different phases of the hydraulic surcharge [7]. It is not remarkable that the global authorities are interested in flood prevention and mitigation to address this devastating effect [8]. Urban flood prediction and simulation are essential for reducing and preventing the damage from urban flood crises

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