An Assessment of Fish Habitat of Natural Fishway by Hydraulic Model Experiments and Numerical Analysis

Abstract

It is increasing to make an efforts on preventing natural river environment and preserving natural river ecosystem as development is unavoidable. In the case of inconsistent river flow caused by reservoir development, fishway is an alternative to secure fish diversity and preserve existing river ecosystem but existing fishway was established without full study for their functions. In this study, hydraulic characteristics of natural fishway established on Beakje weir's right side were analyzed. The results show that the fishway has reasonable depth and velocity condition which inhabit condition is enough for a dominant species. For assessing the optimal design of fishway, the Weighted Usable Area (WUA) was calculated by using two dimensional numerical model under the ordinary flow condition. The comparison results for various pool widths in the fishway show that the designed width has maximum WUA for adult Zacco platypus but WUA is maximized with 1m wider pool width than designed width for spawning.

Evaluating Attraction and Passage Efficiencies of Pool-Weir Type Fishways Based on Hydraulic Analysis

“…where q x = HU; q y = HV; H is the average depth of the flow; U and V are the depthaveraged velocities of x and y directions, respectively; g is the gravity acceleration; ρ is the water density; S 0x and S 0y are the riverbed slopes of the x and y directions, respectively; S fx and S fy are the friction slopes of the x and y directions, respectively; and τ xx , τ xy , τ yx and τ yy denote the horizontal stress factors [19]. The parameters of River 2D model are the Manning's roughness coefficient.…”

“…τ denote the horizontal stress factors [19]. The parameters of River 2D model are the ning's roughness coefficient.…”

Evaluation of By-Pass Fishway Operation for Attraction Efficiency Based on GPS Drifter Field Experiments

“…where q x = HU, q y = HV, H was the average water depth, U and V were average velocities in the x and y directions, respectively, g was gravitational acceleration, ρ was water density, S 0x and S 0y were riverbed slopes in the x and y directions, respectively, S f x and S f y were friction slopes in the x and y directions, respectively, and τ xx , τ xy , τ yx , and τ yy were horizontal stress factors [14]. The parameters of River2D are coefficients of roughness (or roughness height) and viscosity.…”

Assessment of Influx Efficiency at By-Pass Fishway Using Two-Dimensional Physical Habitat Simulation Model -Focused on Zacco Platypus-

“…Kim(2008aKim( , 2008b)은 어도 수리모형실험을 통하여 흐름에 따른 어류 이동을 비교하는 방법으로 어도의 적정 형태를 결정하였 다. Lee et al (2012)은 수치해석 및 수리모형실험을 통하 여 자연형 어도의 수리특성을 분석하였고, 유량점증방법 론을 2차원 물리서식처 모의 모형인 River2D에 적용하여 백제보 자연형 어도의 어류서식처를 평가하였다. K-water (1995) 와 Woo et al (1998)은 경험적인 방법으로 유황 곡 선을 이용하여 특정 추천 유량을 설정하였으며, Kim et al (1996aKim et al ( , 1996b 국외에서도 다양하게 변하는 어류의 서식처에서 보다 정확한 수심과 유속을 모의하기 위해 2차원 수리모형이 개발되어 이를 적용한 연구가 진행된 바 있다.…”

“…River2D 모형의 구성은 River2D_Bed, River2D_Mesh, River2D_Habitat 등 3가지 모형으로 구성되어 있으며, 모의 수행절차를 도식화하면 Fig. 1과 같다 (Oh et al, 2008 (Lee et al, 2012).…”