裁弯河道内生物栖息地改造及生态流量估算EI北大核心CSCD

为探讨砾石群布置对裁弯取直河道内生物栖息地的改造效果,并估算改造河段的生态流量,以江西金沙溪为研究区域,选取鲢鱼为研究对象,采用正交试验法和数值模拟方法,研究了最优砾石群的布置形式,并采用生物栖息地法估算了河道内生态流量。结果表明:流量对裁弯河道生物栖息地加权可用面积(WAU)的影响最大,砾石堆积体边长次之,堆积体间距最小,单体砾石边长20 m、砾石间距9 m为最优砾石群布置形式;在原河道平滩流量条件下,裁弯取直后河道内WAU较原河道减小约30%,布置最优砾石群后,裁弯河道内WAU较原河道增加20%,生物栖息地自然化改造效果明显,且不影响河道行洪能力;原河道基本生态流量为50 m^(3)/s,目标生态流量为718 m^(3)/s,改造后裁弯河道基本生态流量为218 m^(3)/s,目标生态流量为618 m^(3)/s。

Reconstruction of biological habitat and ecological flow estimation in curving cut-off river channel

To explore the effect of gravel group arrangement on the reconstruction of biological habitats and estimate the ecological flow in the reconstructed reaches, selecting Jinshaxi River in Jiangxi Province as the study area, silver carp as the study object, the optimal gravel group arrangement pattern was examined based on methods of orthogonal test design and numerical simulation, and the river ecological flow is estimated based on biological habitat method. The results indicated that flow has the most influences on the weighted usable area (WAU) of the habitat, followed by side length of the gravel accumulation body, while distance between the accumulation bodies has the least influences. The optimal gravel group arrangement type should have 20.m side length of single gravel and 9.m spacing between adjacent gravels. The WAU in the curving cut-off river channel is decreased by approximately 30% compared to that in the original river channel under bank-full discharge condition. The arrangement of optimal gravel group improves WAU by 20% compared to that in the original channel, and significantly improve the biological habitat in the curving cut-off river, with little influence on the flood discharge capacity. The basic ecological flow and the target ecological flow of the original river were 50m3/s and 718m3/s, respectively. After the reconstruction in curving cut-off river channel, the basic ecological flow and optimal ecological flow are 218m3/s and 618m3/s, respectively.