Excessive sediment deposition in eco-friendly physical structures introduced in agricultural canals sometimes damages the function of these structures as fish habitats. This study reports the spatial and temporal changes in bed elevation in a canal section where a set of six fish nests and one fish pool were installed. Field observations and numerical simulation using the two-dimensional hydrodynamic model, Nays2DH, were conducted to describe the circumstances in which sediment deposition and scouring occur in the structures. The bed topography of the canal section was surveyed 12 times during 2016–2019, at 19 transverse cross sections of the area. The measured bed elevation was interpolated to estimate its spatiotemporal variation, sedimentation timing, and change in sediment volume. The results of this work clarified that deposition and scouring occurred in a 1-year cycle in the fish nests. The accumulation of sediment in the whole study area was found to be lower than expected. These results could provide insight for designing fish pools and fish nests that require less maintenance in an eco-friendly canal influenced by soil transport from surrounding paddy fields.

在农业运河中引入的生态友好型物理结构中过多的沉积物沉积有时会破坏这些结构作为鱼类栖息地的功能。这项研究报告了在安装了六个鱼巢和一个鱼池的运河段河床高程的时空变化。使用二维流体动力学模型Nays2DH进行了现场观察和数值模拟，以描述结构中发生沉积物沉积和冲刷的情况。在2016-2019年期间，对该地区的19个横断面进行了12次渠道剖面的河床地形调查。对测得的床高进行内插，以估算其时空变化，沉积时间和沉积物体积的变化。这项工作的结果表明，沉积和冲刷是在鱼巢中进行的，周期为1年。发现整个研究区的沉积物堆积低于预期。这些结果可以为设计池塘和鱼巢提供见识，而这些池塘和鱼巢在受周围稻田土壤运输影响的生态友好型运河中需要较少的维护。