Characteristics and risk management of urban surface flooding in Guangzhou, China: Insights from 2022 ground monitoring

Abstract

Study RegionGuangzhou, ChinaStudy FocusOur research, based on the meticulous collection and rigorous statistical analysis of ground monitoring records for the entire year of 2022 in Guangzhou, delves into the spatio-temporal distribution patterns, evolution processes, flood formation mechanisms, and corresponding disaster mitigation strategies of urban surface flooding related to the capacity of drainage system in the region. New Hydrological Insights: The urban surface flooding (USF) in Guangzhou in 2022 provides key insights for flood risk management. The overall spatial distribution of USF risk in Guangzhou is stable, but specific flood locations during rainstorms vary due to factors such as rainfall conditions and drainage efficiency. This complexity highlights the diverse nature of USF challenges. The frequency of USF events varies significantly across months and dates, with a higher occurrence during the flood season. However, there is a noticeable extension of flood risk into the non-flood season, challenging traditional flood season concepts. USFs peak within 50 minutes, demanding urgent action within 25 minutes, underscoring the need for an efficient emergency response. Certain areas, times, and processes contribute more to the overall flood risk, emphasizing the importance of focusing on these high-risk factors for effective management and resource allocation. The study also reveals the prevalence of Surface Runoff-type Floods, challenging existing USF simulation methods and necessitating a reevaluation and improvement in the maintenance and design of urban rainwater inlets. The study suggests vigorously promoting private proactive flood mitigation behavior and proposes a hierarchical, classification-based approach to urban flood risk control. Comprehensive intervention in the urban runoff formation process is emphasized for effective flood risk management.

Keywords

• Urban Surface Flooding
• Temporal and Spatial Distribution
• Development Characteristics
• Formation Mechanisms
• Risk Management