基于湿周法的河道最小生态需水量多目标评价模型

Multi-objective evaluation model for minimum environmental flows based on wetted perimeter method

以湿周与流量关系为基础,建立了基于多目标评价方法的河道最小生态需水量估算模型,以湿周最大和河道流量最小作为栖息地保护和水资源开发利用的目标,采用理想点法求解,以增江下游麒麟咀站为例计算河道最小生态需水量,并将该模型的计算结果与斜率法和曲率法的计算结果进行了比较分析。结果表明:增江下游河道最小生态需水量阈值范围为20.8～26.3 m3/s,相应的平均流速范围为0.42～0.44 m/s;模型计算结果比传统的湿周法适用性更强,且能较好体现生态用水和经济用水的均衡发展。

A multi-objective evaluation model is established to estimate the minimum environmental flows（MEF） based on the relationship between wetted perimeter and discharge.Regarding the maximum wetted perimeter and the minimum river discharge as objectives for habitat protection and water resources utilization respectively,the model is solved by means of the ideal point method,and MEF in the downstream of Zengjiang River is calculated by the multi-objective evaluation model and compared with that calculated by the slope method and the curvature method.The results show that the MEF threshold at Qilinzui station in the downstream of Zengjiang River ranges from 20.8 to 26.3 m3/s,and the corresponding average velocity is from 0.42 to 0.44 m/s.The results calculated by the multi-objective evaluation model have stronger applicability for determination of MEF than those by the traditional wetted perimeter method,and they can better reflect the balanced development between the ecological and economic water uses.