Flood modeling of Sungai Pinang Watershed under the impact of urbanization

Abstract

Urbanization has been a worldwide development trend, which regulates river courses, impervious surfaces and drainage systems. Urbanization causes hydrological effects, including increased runoff volumes, peak discharges and flow concentrations. This manuscript selects the Malaysian Sungai Pinang watershed as a case study to illustrate these land use, channel and flooding changes of Asian coastal cities. The Landsat satellite remote sensing images were first used to estimate the land use/land cover changes of the Sungai Pinang watershed by using SVM algorithm, and the results shows the urbanization was very rapid in the past decades, with the urbanization rate reached 46.41% in 2018 based on the build area rate. River channel characteristics also changed significantly, from natural river to concrete channel. Some flood resilience measures for coastal cities experiencing urbanization are also proposed for development and flood mitigation. Moreover, a flood forecasting model of the Sungai Pinang watershed is established herein. The simulation results of the Liuxihe model constructed in this study conforms to hydrological regularities and can provide a technical reference for flood control and disaster reduction. However, it is necessary to pay attention to the uncertainty of the forecast results.