Assessing urban potential flooding risk and identifying effective risk-reduction measures

Area of Science:

• Environmental Engineering
• Urban Hydrology
• Geographic Information Systems (GIS)

Background:

• Flood protection is a critical function of urban drainage systems, with significant economic and health impacts.
• While heavy rainfall flooding is well-studied, simulating minor flooding caused by operational deficiencies or human behavior remains complex.
• Existing methods struggle to provide actionable recommendations for utility managers due to the varied causes of blockages.

Purpose of the Study:

• To develop a method for representing and assessing urban flooding risk, focusing on minor flooding causes.
• To identify potential management responses and provide clear information for decision-makers.
• To analyze the relative importance of different blockage causes in a real-world urban context.

Main Methods:

• Utilized Geographic Information Systems (GIS) for spatial analysis.
• Collected and analyzed operational and maintenance data from 4895 flooding interventions.
• Applied the developed method to the Urban Community of Bordeaux, France (2009-2011).

Main Results:

• Identified the relative importance of various causes, including human behavior (e.g., grease) and operational deficiencies (e.g., roots).
• Demonstrated that blockages are not solely due to network deterioration but also influenced by environmental and operating conditions.
• Highlighted the need for collaboration between municipal departments (e.g., roads, green spaces) for effective management.

Conclusions:

• The proposed GIS-based method effectively assesses flooding risk and identifies management strategies for minor flooding.
• Context-specific analysis is vital for developing appropriate flood protection strategies.
• Effective urban drainage management requires a holistic approach considering external factors and inter-departmental cooperation.