为发挥灌区用水调度决策潜能，以黑龙江省长岗灌区为研究区，提出一种基于全过程输水损失的灌区渠系优化配水多目标模型，该模型充分考虑灌区骨干渠系内不同渠段、渠道之间的水量平衡和各级渠道的输水能力，兼顾渠系输水损失、配水及时性与公平性多目标的协同，优化决策配水流量与输水历时。此外，利用随机森林模型预测未来气候变化情境下灌区的供需水量，基于此，计算未来气候模式下的渠系输水损失并获得长岗灌区渠系优化配水方案。结果表明：同一生育阶段内上级渠道不同渠段的输配水损失水量占上级渠道输配水损失总量的比例差异性显著，任一生育阶段内上级渠道靠近渠首的第一个渠段的输配水损失水量占比最大（返青期、抽穗开花期和乳熟期均为20.71%、分蘖期为21.21%、拔节孕穗期为25.43%）；通过渠系优化配水模型得到长岗灌区作物全生育期渠系输配水总量为230.51万m3，总配水历时为494.32 h，输水损失总量为8.66万m3，与灌区采用经验系数法计算的输配水损失水量相比，输水损失减少24.89%，显著提高输配水效率。该模型有助于提供科学、合理的渠系配水方案，为综合提升灌区水资源管理能力和精细化管理水平提供决策支持。

Irrigation districts usually have characteristics of a high water demand and low water use efficiency, and irrational canal system transmission and distribution schemes lead to water waste, further aggravating the contradiction between water supply and demand in irrigation districts. The optimal water distribution model of canal system should provide scientific and effective methods and tools for formulating optimal water distribution schemes of canal system to cope with future climate change, so as to support the efficient allocation of water resources in irrigation districts.Based on this, the Changgang Irrigation District of Heilongjiang Province is taken as the research area, and a multi-objective model for optimizing water distribution of irrigation canal system is proposed based on the whole process of water transmission loss. The model fully considers the water balance, irrigation time, irrigation water volume and canal water conveyance capacity between different canal sections in the main canal system of the irrigation district, and takes into account the three objectives of water saving, timeliness and fairness in the process of water transmission and distribution in the canal system of the irrigation district. At the same time, the Random Forest model was used to predict the water supply and demand of the irrigation district under future climate change scenarios, which was used as a model input to accurately calculate the loss of canal transmission, and to obtain an objective and practical optimal water distribution scheme for the canal system in Changgang Irrigation District.The results showed that the proportion of water loss from transmission and distribution to the total water loss from transmission and distribution of the upper channel in different canal sections of the upper channel within the same fertility stage was significantly differentiated, and the first canal section of the upper channel close to the head of the canal within any fertility stage accounted for the largest proportion of water loss from transmission and distribution. Through the canal system optimization water distribution model, the total amount of canal system water transmission and distribution in Changgang Irrigation District during the whole crop fertility stage was 2,305,100 m3, the total water distribution time was 494.32 h, and the total amount of water loss in transmission and distribution was 86,600 m3, which was 24.89% less than the amount of water lost in transmission and distribution calculated by the empirical coefficient method in the irrigation district, and it significantly improved the efficiency of water transmission and distribution. When planning and constructing high-standard seepage control facilities, it is suggested that the competent authority of the irrigation district may give priority to the construction of canal section 1, canal section 2, canal section 3 and canal section 6 of the upper channel and the six, ten and eleven branches of the lower channel to optimize the allocation of water resources in the irrigation district and to reduce the loss of water transmission.It is shown that the model helps to provide scientific and reasonable canal system water distribution scheme, realizes the synergistic enhancement of water conservation, timeliness and fairness in the process of canal system water transmission and distribution in the irrigation district, and can be applied to other water-scarce irrigation districts, so as to provide decision-making support for comprehensively enhancing the capacity of water resources management and the level of refined management in irrigation districts.