Abstract: The conveyance channel of water diversion project is featured with long distance and complicated geological environment. In order to standardize the safety of project operation, it is necessary to evaluate potential risks and propose corresponding measures. Six failure modes are summarized: structural cracks, poor water delivery in ice period, instability of canal slope, material aging, abnormal leakage, and foundation defects. On the basis of FMEA (Failure Mode & Effects Analysis), a multi-granularity linguistic evaluation method that can be converted to interval intuitionistic fuzzy numbers is adopted to evaluate the severity (S), difficulty of detection (D), and occurrence (O) of the six failure modes. Interval intuitionistic fuzzy entropy is used to calculate risk factor weights. And finally a ranking model for each failure mode is built based on the TODIM (Tomada de Deciso Interativa Multicritérion) method. The final ranking result suggests that the risk of abnormal leakage is the largest, and the risk of poor water delivery in ice period is the smallest. The feasibility and validity of the calculation results are verified by comparison with the ranking results of traditional RPN and TOPSIS methods. The TODIM-FMEA risk assessment model offers a new idea for the risk assessment of water diversion projects.

Key words: South-to-North water diversion, water conveyance channel, FMEA, interval intuitionistic fuzzy, TODIM