Emergency Control Strategies Research for Sudden Pollution Incident in Long-Distance Water Diversion Tunnels

This study investigates emergency response strategies for sudden pollution incidents in long-distance water diversion tunnels. The tunnel section of the Yin Chao Ji Liao Project in Inner Mongolia is used as a case study. A one-dimensional hydrodynamic water quality model was developed in Storm Water Management Model (SWMM) to analyze pollutant transport characteristics in the tunnel under various operating conditions. Based on the actual engineering conditions, control scenarios with multiple flow rates and multiple gate combinations were set up. Emergency control strategies for sudden pollution events were developed to address extreme pollution scenarios. The feasibility of scheduling gate operations according to pollutant transport response time for effective pollution mitigation was evaluated. On this basis, an expression for calculating gate-operation timings for emergency pollution control was derived. The results indicate that the peak concentration in the tunnel shows a decreasing trend as the flow rate increases, and the change process shows a stage-by-stage characteristic. Accounting for the response time of water discharge can improve pollution disposal efficiency by 4.34–52.14%. The efficiency gains become increasingly pronounced at higher flow rates, indicating that this strategy can effectively enhance water discharge efficiency. Installing water quality monitoring instruments near the drainage gate section helps improve the precision of regulation and effectively enhances the timeliness and accuracy of operations, and provides a theoretical reference for on-site emergency regulation and control.