颍河河抱湾圩段裁弯取直分析研究

Analysis and Research on Cut-bending Straight for Hebaowan Polder Reach of Ying River

通过比较颍河河抱湾圩段河道原河道退堤方案与裁弯取直方案,分别建立MIKE21模型进行模拟计算,分析2种方案的河水流速、流态分布、工程占地和搬迁人口。结果表明,裁弯取直方案在较大程度上改变了颍河河势,改善了河道蜿蜒现状,使水流下泄更为畅通,较小的河道弯曲系数有效地减小了迎流顶冲对河岸的冲刷,而新开辟的两段河道的主槽流速均较大,冲刷作用较强;相比原河道退堤方案,裁弯取直方案会使三湾圩、河抱湾圩四面环水,极大地改变了圩区群众的生产生活方式,产生了较大的社会影响。

In this paper,the original river channel embankment retreat scheme and the cut-bending straight scheme are compared for the Hebaowan polder reach of Ying River.The MIKE21 model is established for simulation.The river water flow velocity,flow pattern distribution,engineering occupation and relocation population of the two schemes are analyzed and compared.The cut-bending straight scheme greatly changes the Ying River regime,improves the meandering status of the river,and makes the flow discharge more smooth.The smaller river bend coefficient effectively reduces the scouring of the river bank by the headward scouring,while the main channel velocity of the new excavated two reaches of the river is large and the scouring effect is strong.Compared with the original river channel embankment retreat scheme,the cut-bending straight scheme will make the Sanwanpolder and Hebaowan polder surroundedby water,which will greatly change the production and life style of the polder people and bring great social impact.