Green infrastructure optimization considering spatial functional zoning in urban stormwater management

Area of Science:

• Environmental Engineering
• Urban Planning
• Hydrology

Background:

• Urban stormwater management faces challenges from climate change and urbanization, necessitating alternatives to traditional drainage systems.
• Green infrastructure (GI) offers a complementary solution, but its multi-functional nature requires careful objective selection for optimal planning.
• Spatial functional zoning is crucial for tailoring GI strategies to specific urban needs.

Purpose of the Study:

• To propose and evaluate a novel Green Infrastructure (GI) optimization method incorporating spatial functional zoning.
• To identify optimal GI solutions for distinct zones: Flood Risk Control Zone (FRCZ) and Total Runoff Control Zone (TRCZ).
• To support decision-making for stakeholders in GI planning and design.

Main Methods:

• Division of the study area into FRCZ and TRCZ based on local conditions.
• Coupling of a hydrological model with an optimization algorithm to determine Pareto fronts and non-dominated solutions.
• Application of the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) for decision support.

Main Results:

• Optimal GI solution for FRCZ achieved 60.49% flood risk reduction at an average annual life cycle cost of 0.20 × 10⁸ CNY.
• Optimal GI solution for TRCZ achieved 22.83% total runoff reduction at an average annual life cycle cost of 0.17 × 10⁸ CNY.
• The integrated approach successfully identified trade-offs between multiple optimization objectives.

Conclusions:

• Spatial functional zoning is an effective strategy for optimizing Green Infrastructure (GI) planning.
• The proposed integrated modeling approach provides valuable insights for balancing cost and performance in GI design.
• This study offers a practical framework for stakeholders to enhance urban stormwater management through strategic GI implementation.