面向流域水环境改善的潮汐河道闸门调度优化研究：以相互独立的圩内河网为例

以我国南方某5个相互独立的圩内河网为研究对象，针对感潮河段的特征建立水动力水质耦合模型，比较不同闸门调度策略下的水质改善效果。结果表明：1)圩内河网应在大潮期进行换水，相对小潮期换水最多可缩短7 h的水力停留时间。以示踪剂工况结果为依据，针对进出水闸门距离较短河网，采用单向流调度策略启闭闸门，相对往复流最多可缩短14.18 h的水力停留时间；针对进出水闸门距离较长的河网，采用开启双侧闸门进水从中心排河排水的往复流闸门启闭策略，相对单向流调度策略最多可缩短3.18 h的水力停留时间。2)水质结果表明，应先利用水系连通方式打通断头河，并采用前述的闸门调度策略，最终本片区河网平均水质达到GB 3838—2002《地表水环境质量标准》Ⅳ类水的断面比例增长了7.3%。研究结果为基于水动力水质改善不同地理特征圩内潮汐河网的闸门调度提供了参考。

REGULATION OPTIMIZATION OF TIDAL RIVER GATES FOR WATER ENVIRONMENT IMPROVEMENT IN THE RIVER BASINS:A CASE STUDY ON INDEPENDENT POLDERS' RIVER NETWORKS

This study took five independent polders’ river networks in southern China as the research objects, established a hydrodynamic water quality coupling model according to the characteristics of the tidal reaches, and compared the water quality improvement effects under different gate scheduling strategies. The results showed that: 1) for the polders’ river network, water exchange should be carried out during the spring tide period, and the hydraulic retention time could be shortened by up to 7 hours compared with the neap tide period. Based on the results of the tracer operating condition, for the river network with a short distance between the inlet and outlet gates, the one-way flow scheduling strategy should be used to operate the gate, which could shorten the hydraulic retention time by up to 14.18 hours compared with reciprocal flows. For the river network with a long distance between the inlet and outlet gates, the reciprocal flows operation strategy of opening the gates on both sides to discharge water from the central drainage could shorten the hydraulic retention time by 3.18 hours, compared with the one-way flow scheduling strategy. 2) the results of water quality showed that the deadhead river should be opened up first by water system connection, and then the aforementioned gate scheduling strategy should be adopted. The proportion of the polders’ river network sections whose water quality reached class IV increased by 7.3%. The results of this paper can provide a reference for the improvement of hydrodynamic and water quality for gate scheduling of tidal river networks in different geographical features.