• Korean Journal of Ecology and Environment
• /
• v.46 no.2
• /
• pp.185-191
• /
• 2013

This study were classified the type of fishway installed on the tributary of Nakdong River, and analyze the state was to establish a management plan. As a result showed low installation ratio of fishway which includes 9,164 weirs at the 786 streams of the tributary of Nakdong River and 1,263 fishways. The type of fishway is shown as 62% for standard type and 38% for non-standard type. Assessment results of fishway condition, the ones in good condition, moderate and poor condition fishways are examined as 28%, 66%, 6%, respectively. In the past, there happened to install the fishways without discussing with fishery research institution but it is judged to install the verified fishways through powerful legal remedy and enable each community to control the fishways voluntarily through the support of government after installing the fishways.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.18 no.6
• /
• pp.50-59
• /
• 2014

In this paper, Reinforced concrete (R/C) and R/C+steel plate concrete slab was carried out by SAP2000 software program in order to compare the stability of the multi-functional fishway, that is Bonggok fishway, built at Bonggok river recently in Gumi city, when the size of underground passage is $1m{\times}0.2m$, $1m{\times}0.4m$, $1m{\times}0.6m$ and the velocity is 0.8m/s, 1.2m/s, 1.6m/s respectively for the S2 (R/C+S/C). The analysis shows the maximum stress of S2 decreases less 26~50% than that of Bonggok, bending moment of sidewall decreases less 28~54%, maximum stress of side wall decreases less 17~31%, bending moment of upper slab decreases less 24~47%, maximum stress of upper slab decreases less 4~20%, and bending moment decreases less 10~27% than that of Bonggok. The complementation is required as much as the following percent; 27% and 25% for the maximum stress and bending moment of underground passage, 15% and 24% for the side wall maximum stress and bending moment, and 10% and 14% for the upper slab maximum stress and bending moment, respectively. This result shows that the S2 is greatly superior to that of the Bonggok fishway, and underground passage size of $1m{\times}0.4m$ is superior to that of $1m{\times}0.2m$ or $1m{\times}0.6m$, and R/C+S/C slab is superior to that of R/C slab. This result is expected to be the basic data for the construction and design of the multi-functional fishway.

• Journal of Korea Water Resources Association
• /
• v.55 no.1
• /
• pp.99-109
• /
• 2022

This study was intended to suggest the applicability of stepped boulder fishway using the concept of traditional boulder weir, focusing on the problems of existing concrete pool-and-weir fishways installed in mountain streams. To achieve this purpose, a stepped boulder fishway was designed and constructed as a pilot project in consideration of ascending capacity of the selected target fishes. Under the given discharge conditions, the hydraulic characteristics of the fishway were investigated in the field, and the characteristics and ascending capacity of the fishes were compared and analyzed. The fishway had a short length and steep slope, but the mean drops between each baffle were the range of 0.15 to 0.29 m, and this range satisfied the limit condition of about 0.40 m, which was in the limit of the drop that target fishes can ascend. The mean velocities of each baffle and pool were 0.82 to 0.87 m/sec and 0.13 to 0.24 m/sec. This result satisfied the conditions of burst speed (10 to 30 times of body length) and mean velocity of the resting pool (7 to 25% of burst speed) for target fishes. Since the bottom surface of the pool formed of boulders had a gentle reverse slope and rotational flow did not occur, the efficiency of fishway can be increased, and it will also be possible to solve the maintenance problem by flushing bed materials.

• Journal of Ecology and Environment
• /
• v.39 no.1
• /
• pp.43-49
• /
• 2016

Fishways are constructed to provide longitudinal connectivity of streams or rivers where their flow has been altered by in-stream structures such as dams or weirs. Nature-like fishways have an additional function of providing fish habitats. In the study, we estimated the role of a nature-like fishway (length: 700 m, slope: 1/100) for fish habitat by using two dominant species in the Sangju Weir, Nakdong River, to calculate the optimal ecological flow rate using Physical HABitat SIMulation (PHABSIM). To identify the dominant species that used the fishway, we conducted trap monitoring from August to November 2012 at the fishway exit. The dominant species were Zacco platypus and Opsariichthys uncirostric amurensis with a relative abundance of 62.1% and 35.9%, respectively. Optimal habitat suitability indices (HSIs) for Z. platypus and O. u. amurensis were calculated as 0.6-0.8 m/s (water velocity) and 0.2-0.4 m (water depth), and 0.5-0.7 m/s (water velocity) and 0.1-0.3 m (water depth), respectively. The optimal ecological flow rates (OEFs) for Z. platypus and O. u. amurensis were 1.6 and 1.7 cubic meter per second (CMS), respectively. The results of the study can be used in a management plan to increase the habitat function of nature-like fishways in the Sangju Weir. This methodology can be utilized as an appropriate tool that can determine the habitat function of all nature-like fishways.

• Journal of Korea Water Resources Association
• /
• v.46 no.6
• /
• pp.629-642
• /
• 2013

In this study, the efficiency of the by-pass fishway installed at Kangjung-Goryong Weir in Nakdong River was assessed by using River2D which is a two-dimensional physical habitat simulation model. The model was calibrated and validated through the measured water elevation. The assessment was performed according to flow condition such as flood, normal, and low flow. Especially the low flow condition was focused on because the target fish, Zacco Platypus, have moved frequently up and downstream at the spawning season from April to June. From simulation results, it can be deduced that the influx efficiency and the passage efficiency of the fishway in the low flow is higher than that in the flood and normal flow due to occurrence of proper velocity at fishway entrance.

• Journal of Korean Society of Disaster and Security
• /
• v.16 no.2
• /
• pp.65-73
• /
• 2023

Fishways are essential structures that must be installed in rivers to facilitate the movement of fish between upstream and downstream areas. However, the efficiency of fish passage varies depending on the flow conditions within the fishway. Therefore, this study examined the fish-friendly flow characteristics within a stepped fishway at different overflow depths using FLOW-3D, and conducted experiments for model validation. The key parameters affecting fish swimming ability include velocity, turbulent kinetic energy, and energy dissipation rate. These factors were assessed using a simulated fish species, the zacco platypus, to evaluate the suitability of fish-friendly flow condition. It was confirmed that overflow depth significantly influences fish behavior, and an appropriate overflow depth is required for stepped fishway design. The results of this study are expected to serve as fundamental data for the design of stepped fishways in the future.

• Korean Journal of Environmental Biology
• /
• v.37 no.4
• /
• pp.726-734
• /
• 2019

To understand the relationship between water velocity in a fishway and fish morphology, the fineness ratio of fish, expressed as the standard length to the body depth, was measured. The fineness ratios of fish groups belonging to Cyprinidae, Acheilognathinae, Centropomidae, and Centrachidae were relatively low. The FRs of other groups, excluding eel-shaped types of fish, were over 4.5, indicating streamlined structures. The fineness ratios of Korean fish were classified into three different types: type I was Bitterling-Carp group that favored a slow-flowing pool habitat(FRs ranged from 2.1 to 3.3), type II was the Chub group representing streamlined types (FRs FRs ranged from 3.7 to 5.2), and type III was the Smelt-Barbel fish group that preferred riffle-run habitats with high velocity (FRs is over 5.2). Fish abundance analysis of fish using the fishway during the experimental periods showed a relatively high abundance of both type II and III compared to type I. The FRs of the fish passing through fishway(velocity 0.5-1.0 m s^-1) ranged from 4.5 to 5.0, indicating that the fish using the fishway were mainly the streamlined type. As one of the standard fishways in Korea, the flow rate of the ice harbor type ranged from 0.2 to 2.6 m s^-1. The FR values of the fish groups using the fishway ranged from 4.3 to 5.0. In contrast, the flow rate measured in an artificial channel type of fishway (same as a natural type of fishway) ranged from 0.1 to 1.9 m s^-1 and the FR values for the fish groups using a natural type of fishway ranged from 3.3 to 5.3. The low FR values in natural fish are considered to be due to differences in the flow rates between the two types of fishways.

• Proceeding of EDISON Challenge
• /
• 2015.03a
• /
• pp.618-622
• /
• 2015

어도(fishway)란 강이 댐과 같은 인공물로 막혀있을 때 물고기가 지나갈 수 있도록 만든 통로이다. 본 연구에서는 전산유체해석 프로그램인 EDISON_CFD 시스템을 활용하여 아이스하버식 어도 내 월류부(rollway)에서 유체의 수직흐름특성을 분석하였다. 어류는 소상과 강하시 어도 내의 흐름에 민감하므로, 흐름에 영향을 주는 요인을 분석하는 것은 중요한 문제이다 어도는 2차원으로 간략화하여 모델링하였으며, 강의 유속, 어도의 기울기, 월류부 높이를 변화시키며 이들이 어도 내의 흐름특성과 어떤 관계가 있는지 분석하였다. 또 속도 증가에 따른 수면파의 파장 변화를 프로우드수와 연관지어 설명하였고, 레이놀즈수가 어도 내의 흐름특성과 밀접한 관련이 있음을 확인하였으며 기 설치된 어도의 문제점을 보완할 수 있는 방법을 제시하였다.

• Journal of Environmental Impact Assessment
• /
• v.21 no.6
• /
• pp.879-891
• /
• 2012

The objective of this study was to evaluate seasonal patterns and diel variations of fish movements in the Juksan Weir which was constructed in 2010 at the down-stream of Yeongsan-River watershed. For this study, we monitored day-and-night movement(24 Hr cycle) and seasonal fish migration(June ~ August) patterns in 2011 along with species compositions and abundances depending on the locations of the traps within the fishway. Total number of species sampled was 14 and the total number of individuals was 1,263 with only the size-fractions(as total length) of the fish < 20 cm during the study. Seasonal analysis of fish movement in the fish way showed that highest frequency in the movement occurred in June - July, which is closely associated with a spawning peak season. The most dominant species using the fishway was Squalidus chankaensis tsuchigae, and this species turned out to be 26.9% of the total in the use rate of fishway. Daily monitoring of fish movements showed that most frequent movements occurred between 18:00 PM and 21:00 PM when the fish have a feeding time generally. The migratory fish were not found in the fishway during the study. Mean current velocity during the study $0.42{\pm}0.02ms^{-1}$(n = 42), and there were no significant statistical differences(p > 0.05) among the daily and monthly velocities in the fishway. The use rate of fish passage, in terms of fish species, was 48%, compared with total sampling of fish species(29 species) at the down-river regions during the same period, indicating a low use rate. Further continuous long-term monitoring should be conducted to evaluate the impacts of the weir construction in the river.

• Ecology and Resilient Infrastructure
• /
• v.7 no.4
• /
• pp.308-319
• /
• 2020

In this study, the field applicability of the recently constructed multifunctional fishway in Seomunbo, Yeongcheon-si, and Gyeongsangbuk-do were examined. The analysis variables were R/C slab (S1) and R/C+S/C slab (S2), the underground passage standard areas (width × length) were 1.4 m × 0.2 m, 1.4 m × 0.3 m, and 1.4 m × 0.6 m, and the flow velocities were 0.8, 1.2, and 1.6 m/s. As a result of the analysis, the safety of the design of Seomunbo was evaluated. The analysis showed compared to the Seomoon Weir fishway, the maximum stress of S2 decreased by 24 - 32%, the bending moment of the underground passage decreased by 16 - 33%, the maximum stress of the sidewall decreased by 20 - 36%. In addition, the bending moment of the upper slab decreased by 17 - 33%, the maximum stress of the upper slab decreased by 9 - 28%, and the bending moment decreased by 19 - 33%. Complementation was required in the following percentages: 18% and 14% for the maximum stress and bending moment of the underground passage, respectively, 15% and 17% for the maximum sidewall stress and bending moment, respectively, and 11% and 16% for the upper slab maximum stress and bending moment, respectively. The results showed that S2 was superior to that of the Seomoon Weir fishway, and the underground passage size of 1.4 m × 0.3 m was superior to those of 1.4 m × 0.2 m and 1.4 m × 0.6 m, and R/C+S/C slab was superior to that of R/C slab. The findings are expected to be useful for constructing and designing the multifunctional fishway.