Urban Runoff Change Detection for Smart City Water Management: A Case Study of Liede Creek in Southern China

摘要

Rapid urbanization caused significant land use/cover (LUC) changes in the city area, this conversion caused runoff coefficient increasing, which impacted the water availability changes. Detecting runoff coefficient change is the requirement of smart city water management. Traditional lumped hydrological model could not be used for this purpose because its model could not be adjusted with the changed LUCs. Distributed hydrological model derives model parameters directly from terrain properties, thus have the potential to be used to estimate the runoff coefficient changes. In this study, a method is proposed to estimate the flood event runoff coefficient changes which dividing the study area into irregular cells based on satellite remote sensing imagery, and calculate the runoff production by employing the runoff production modular of Liuxihe model. In this study, the Liede Creek, a small watershed in the center of Guangzhou City with a drainage area of 18.70 km2 and a length of 6.35 km, was case studied. Changed LUCs increased the runoff coefficient, thus worsening the urban flood and caused more flood damages. In this study, the LUCs change series of Liede Creek in Guangzhou City in the past 30 years has been collected and post-processed, which are used to drive the Liuxihe model for runoff production calculation. Three observed precipitation in recent years was collected to make the runoff production simulation. Flood event runoff coefficient changes have been detected, which shows it is a big change in the past decades.