ISPIV2017

The 12th International Symposium on Particle Image Velocimetery
June 19 (Mon) – 21 (Wed), 2017 / Grand Hotel, Busan, Korea

EFFECTS OF DOWN SLOPE OF BOTTOM IN POOL-AND-WEIR FISHWAYON MIGRATION RATE OF NIPPONOCYPRIS TEMMINCKII
Kouki Onitsuka1, Juichiro Akiyama2 and Tomohide Takeda2
1 Department of Civil Engineering, Kyushu Institute of Technology, Kitakyushu, Japan

onitsuka@civil.kyutech.ac.jp
2 Department of Civil Engineering, Kyushu Institute of Technology, Kitakyushu, JapanABSTRACT
1.INTRODUCTION
River structures such as dam prevent fish from migrating. Therefore, fishway is constructed in these river to make it easierfor fish to migrate. The elucidation of the most suitable geometric and flow conditions in fishway is tried. The geometricconditions that affect migration rate of fish in pool-and-weir fishway which is adopted all over the world [1] are the drop
between the pools [2], the shape of the notch [3], the length and depth of the pool [4]. These experiments were performed
under the condition that the bottom of the pool is level. However, the gradient of the bottom of the pool is not examined
well. Onitsuka et al. [5] showed that when the bottom slope was set down slope toward upstream side, the migration rate
became high value. Still, his experiment was performed in only one case that the angle of down slope of the bottom is 40°.
So, the most suitable value of the angle of down slope of the bottom is not unravel. In this study, effects of down slope ofthe bottom in pool-and-weir fishway on migration rate of Kawamutsu (Nipponocypris temminckii) are investigated bychanging the value of the angle of down slope toward upstream side and discharge.
2.EXPERIMENTAL SETUP AND METHOD
Figure 1 shows pool-and-weir fishway. Pool length (L) is 0.9m, width (B) is 0.8m and 3 pools are connected in a staircase
pattern. The thickness of the partition wall (Δx) is 0.2m, the drop between the pools (Δy) is 0.15m, the width of the notch(Δz) is 0.16m, the height from the bottom of the pool to the bottom of the notch (H) is 0.3m and the notch is R shape. x axis
is taken in the downstream direction, y axis is vertical direction and z axis is transverse direction. Figure 2 shows theschematic of down slope toward upstream side. Table 2 shows experimental case. The angles of down slope of the bottom(I) are 0, 1/10, 2/10 and 3/10. The discharge (Q) are 1, 3 and 5(l/s). 12 cases are performed in total. The used fish is
Kawamutsu (Nipponocypris temminckii) and the number of fish (N) is 30. Averaged body length ( BL ) is 70mm.
In each case, fish are put into the middle pool. After it is confirmed that Kawamutsu settle down, the swimming behaviorsof fish in the middle pool are recorded with the aid of two sets of digital video cameras for 30 minutes. In addition, thenumber of fish which migrate to the upstream pool (nu) and swimming position are analyzed.
3.RESULTS AND DISCUTION
Figure 3 shows migration rate (nu/N) of Kawamutsu according to discharge (Q). As the angles of down slope of the bottom(I) increase, migration rates show higher value.
Figure 4 shows the contour figure of existing probabilities ( n / N ) that it was calculated by locating the swimming
position of Kawamutsu with every 10s for the case of Q=1 and 5(l/s), I=0 and 3/10. Figure 4(a)~(d) show contour figure ofexisting probabilities in horizontal section. The domains which indicate high existing probabilities approach the left bankand upstream side with the increase of the angles of down slope of the bottom (I). Figure 4(e)~(h) show contour figure ofexisting probabilities in vertical section. In the case of I=0, Kawamutsu are distributed on the downstream side and thebottom of the pool. In the case of I=3/10, the areas of distribution are narrower and the positions of it approach upstreamside than the case of I=0.
Judging from these results, migration rates show higher value because the distance between the positions of Kawamutsu
and the notch become shorter with the increase of the angles of down slope of the bottommFlow(a) I=0

flow

(b)

Flow

y

I=1/10

Flow

x

zy

Flow

(c)
Hz

BL

I=2/10(d) I=3/10
Figure 2 Schematic of down slope
(単位：)

1x

Figure 1 Pool-and-weir fishway

Upstream migration ratenuN

QQ=1(l/s)

N. Temminckii

QQ=3(l/s)

B L = 70(mm)QQ=5(l/s)

0.6

Q (l/s)135Table 1 Experimental caseangle of down slope of bottom
I =0
I =1/10
I =2/10
I =3/10
0-Q1
1-Q1
2-Q1
3-Q1
0-Q3
1-Q3
2-Q3
3-Q3
0-Q5
1-Q5
2-Q5
3-Q5

0.4
0.2
00

1/10

2/10 I

3/10

Figure 3 Upstream migration rate of Kawamutsu(a) 0-Q1 Horizontal section(b) 3-Q1 Horizontal section(c) 0-Q5 Horizontal section(d) 3-Q5 Horizontal section(e) 0-Q1 Vertical section(f) 3-Q1 Vertical section(g) 0-Q5 Vertical section(h) 3-Q5 Vertical section

Figure 4 Contour figure of existing probability

REFERENCES[1] Fuentes-Pérez JF, Sanz-Ronda FJ, Azagra AM and García-Vega A “Non-uniform hydraulic behavior of pool-weir fishways” EcologicalEngineering 86 (2012) pp.5-12[2] Namihira A, Goto M and Kobayashi H “Flow structure and swimming behavior of Leuciscus hakonensis at pool-and-weir type fishway withslope 1/5” Proceeding of Hydraulic Engineering 52 (2008) pp.1189-1194[3] Wada Y “Relation between the ascending path of ayu and fishway structure” Proceeding of the International Symposium on Fishway ’90 inGifu, Japan (1990) pp.445-450[4] Hayashida K, Honda T, Kayaba Y and Shimatani Y “The flow pattern of the pool-and-weir-fishway in the pool and the swimming behavior ofLeuciscus hakonensis” Proceeding of Hydraulic Engineering 44 (2000) pp.1191-1196[5] Onitsuka K, Akiyama J, Noguchi S and Shishido A “Effects of bottom slope in pool-and-weir fishway on migration rate of ayu, Plecoglossus
altivelis altivelis” Environmental System Research 70 (2014) pp.II_115-II_121