基于模糊综合评价方法的内河河网流量分配模型

Fuzzy comprehensive evaluation for flow diversion of inland river network

内河河网水环境改善可通过水体置换实现,对于来流一定的内河河网可通过优化河网的流量分配来实现各河段水体置换。河网流量分配与河网几何特征属性存在着密切的河相关系,当河网流量发生变化,河流自动调整达到平衡后,其纵横剖面形态与流量之间就形成特定的主从变量关系,本文选取河长l、河底比降i、分汊角度а等关键几何特征属性作为流量变化的从变量,引入模糊数学理论及粗糙集理论,运用模糊综合评价法确定不同几何特征属性对河网流量分配的影响权重,用于预测内河河网各河段的流量分配。将该模型应用于福州市内河引水工程水动力环境研究,验证了所建模型的合理性,研究结果对河网配水方案规划或常规运行调度方案比选具有重要的参考价值。

Improvement of water environmental quality in inland river networks can usually be achieved by water replacement. For a network of constant inflows, optimization of its flow diversion has been one of the approaches to implementation of water replacement in its different branches. Due to the close morphological relation between flow diversion and geometrical characteristics of the channel, a special master-slave relationship of the channel cross section and longitudinal profile versus the discharge of the river network will be developed. In this paper, geometrical characteristics are considered as slave variables, such as the river length l, slope bottom i and bifurcation angle α, and their different weights in prediction of the discharge in each network branch were obtained using fuzzy comprehensive evaluation（FCE） based on the fuzzy theory and rough set theory. To verify this method, a FCE model was successfully applied to a hydrodynamic environment study for the inland river diversion project of Fuzhou. The results are helpful in planning water distribution and scheduling operation schemes for the river network.