Understanding the synergistic effect between LID facility and drainage network: With a comprehensive perspective

Area of Science:

• Environmental Engineering
• Urban Planning
• Hydrology

Background:

• Low impact development (LID) is crucial for storm water management, yet its integration with urban drainage networks (UDS) is understudied.
• Existing research focuses on LID parameters, often overlooking the UDS's role in overall system performance.
• LID facilities and drainage networks are interdependent components of a functional UDS.

Purpose of the Study:

• To investigate the synergistic effects of LID facilities and urban drainage networks on UDS performance.
• To analyze how different spatial arrangements of LIDs influence environmental, social, and technological outcomes.
• To assess the impact of rainfall intensity and LID distribution uncertainties on UDS.

Main Methods:

• A case study in Kunming, China, divided into upstream, midstream, and downstream sections with varying network characteristics.
• Development of four LID siting strategies, distributing facilities across different network sections or evenly.
• Hydraulic and topological modeling to evaluate UDS performance under various scenarios and uncertainties.

Main Results:

• The study confirms the existence of synergistic effects between LID facilities and drainage networks.
• Spatial relationships significantly alter UDS performance, influencing urban flooding, combined sewer overflows, and wastewater treatment plant loads.
• Synergistic effects are sensitive to rainfall intensity, necessitating performance evaluation beyond design conditions.

Conclusions:

• Integrated planning of LIDs and drainage networks is essential for optimizing UDS performance.
• Evenly distributing LIDs offers a simplified yet effective strategy due to complex synergistic interactions.
• Understanding these synergistic effects is critical for informed LID planning and improved urban water management.