基于MIKE21 FM模型的河道防浪林行洪影响分析

Study on influence of river wavebreak forest on flood discharge ability based on MIKE21 FM Model

为分析在滩地种植防浪林对河道行洪能力的不利影响,以嫩江干流东阳堤段为例,通过在MIKE21 FM模型中对防浪林进行结构物概化构建数值模型,选取堤前水位、断面水位和断面流速作为输出,比较有、无防浪林时输出位置的水位和流速,定量计算现状防浪林和优选布局条件下设计防浪林种植对河道行洪的影响。结果表明,防浪林的种植会对行洪水位和流速产生影响,且林带越宽、滩地水深越大,防浪林对河道行洪的影响越大;现状防浪林和设计防浪林对研究区河道行洪水位和流速的影响均很微小,对河道行洪不构成威胁。

To study the adverse effect of wavebreak forest on river flood,a numerical model was constructed using MIKE21 FM model,and the wavebreak forest was described by the structure to build the numerical model.Outputs including water level before the dike,average cross-section water level and cross-section velocity were quantitatively compared between conditions with and without wavebreak forest to analyze the effect.The Dongyang Dike of Nenjiang River was taken as an example,and results show that the wavebreak forest influences the changes of water level and velocity.The wider the forest,the greater the water depth,and the greater the influence of wavebreak forest on the flood discharge.Meanwhile,the effect of wavebreak forest on flood discharge capacity is very small under current condition and designed condition on the Dongyang reach.