1. Impression of Clearness

Research by the Wakkun
Research Group

Yurinokai ResearchGroup

Research by Chikyu The Kouseidaiichi eco
Club Research Group Club Research Group

Research by the 23th
Research Group of Senior
University’s Department ofEnvironment

Research by the Central
Japan Construction
Consultant Co. ,Ltd
Mayor of Nagoya City Takashi Kawamura
participated in the Horikawa Cheering Group18

1.1. The Rate of “Clear”, ”Clear a little” and “Neutral”(With TRWKR, No Rain)(1)
The number of sample is less.
93
87
87
25 in 31 research was held on June 27th.

100
H19.4.22～6.30 1st stage90

H19.9.8～12.16 2nd stage

201034

H21.4.1～6.30 5th stage
5756575350453938 3627231812112321

improved

improved
8504339

improved

16→
Inlet of TRWKR

304073

H20.9.28～12.16 4th stage→
Meijo Sewage Plant

504050 50

50→
Nagoya Port

impression of clearness（％）

60

Then most of impression was “Dirty a little”.

H20.4.1～6.30 3rd stage→
Confluence of the Shonai River70→
Confluence of the Shinhorikawa River80

0Minatoshinbashi
Bridge-OsekoBridge

Oseko BridgeMatsushige BridgeMatsushige Bridge
Asahi Bridge

Asahi BridgeJohoku Bridge

Johoku BridgeSanage Bridge

Sanage BridgeSakae Bridge

The impression of clearness between the Sanage Bridge and the Matsue Bridge was improved.
The impression of clearness from spring to early summer is worse than that from autumn to earlywinter.
19

1.1. The Rate of “Clear”, ”Clear a little” and “Neutral”■ How did the impression of clearness between the Sanage Bridge andthe Minatoshinbashi Bridge change?
• In 5th stage, the impression between the Sanage Bridge and the Matsusige
Bridge was better than in the 1st stage. The rate of “Clear”, ”Clear a little”
and ”Neutral” increased.
• In the 3rd and 5th stage (from spring to early summer), the impression wasworse than in the 2nd and 4th stage (from autumn to early winter). The rate of“Clear”,”Clear a little” and ”Neutral” decreased.
• In the 5th stage, from the Sanage Bridge to the Johoku Bridge, the rate of“Clear”, ”Clear a little” and ”Neutral” is 50%. The lower from the Johoku
Bridge to the Asahi Bridge, that rate is 25%. From the Johoku Bridge to theOseko Bridge, it decrease a little. Then the lower Horikawa River, the lessthe rate of “Clear”, ”Clear a little” and ”Neutral”.

( No rain )(2) Effect of TRWKR

1st stage～5th stage

Sanage Bridge - Minatoshinbashi Bridge
0%20%

40%

60%

80%

100%

32％All date3With TRWKR

31415402816392734％(Number of Sample 824)
15(Number of Sample 680)

21％

Without TRWKR 1 81246

・The rate of “Clear”, “Clear alittle”, ”Neutral” withTRWKR was more than
without it. Then theimpression of clearness
between the Sanage Bridge
and the Minatosinbashi
Bridge was improved.

33(Number of Sample 164)

7020104333

With TRWKR
Without TRWKR

3028302117134526→
Inlet of TRWKR30③Neutral

Meijo Water Treatment→
Center50

Confluence of→
The Shinhorikawa Riber

60

40②Clear a little⑤DirtyThe number of sample is less.

→Nagoaya Port

Rate of "Clear", "Clear a little", "Neutral" (%)①Clear
④Dirty a little■Are there any differenceof impression of clearness
whether TRWKR is doneor not ?

Average 34%← with TRWKR← Average 21%
without TRWKR

0Minatoshinbashi BridgeOseko Bridge

314

Oseko BridgeMatsushige Bridge

24121

Matsushige BridgeAsahi Bridge

87296

Asahi Bridge-JohokuBridge

1682

Johoku Bridge-SanageBridge

54167 ←Number of sample

201.2. Criterion for Judgment of the impression of clearness
between the Sanage Bridge and the Minatosinbashi Bridge

Rate of criterion for judgment of impression (%(1) Criterion for Judgment of “Dirty a little ”, “Dirty”
1%
100%

1%( With TRWKR, No Rain )

1%
5%

5%

90%

70%
60%
50%
40%

19%

22%

80%

The sum of ①
Color and ④
Artificial gabage
account for
about 80%.

30%

24%

9%
4%

13%
3%

56%

13%
8%

⑦Others

10%⑥Aspect of life

19%

⑤Bubbling

In 5th stage, “Color”
and “Smell” increased.
62%④Artificial gabage
68%57%

20%③Transparency②Smell10%①Color0%

1st stage

2nd stage

3rd stage

4th stage

5th stage

To Next Slide■ What is the criterion for judgment of impression of clearness
between the Sanage Bridge and the Minatoshinbashi Bridge ?
The sum of ① Color (over 50%) and ④ Artificial garbage account forabout 80%.
21

1.2. Criterion for Judgment of the impression of clearness
between the Sanage Bridge to the Minatosinbashi Bridge

Rate of Criterion for Judgment of Impression (%)(1) Criterion for Judgment of “Dirty a little ”, “Dirty”( 5th Stage, with TRWKR, No Rain )

3%

100%
13%

90%

10%
4%

80%

⑦Others

10%

9%

3%

29%

⑥Aspect of life

14%⑤Bubbling

17%

70%
60%
50%

7%

100%

90%

40%

74%

30%
20%

100%

67%

③Transparency
50%

The number ofsample is small.

10%

The number ofsample is small.

②SmellColor of river0%

Minatoshinbashi
Bridge-OsekoBridge
Numberof sample→
1④Artificial gabage①ColorOseko BridgeMatsue Bridge

Matsue BridgeAsahi Bridge

Asahi BridgeJohoku Bridge

Johoku BridgeSanage Bridge

Sanage BridgeSakae Bridge

23291014

1・In 5th stage, “Color” and “Smell” increased more than in 3rd stage.
・In 5th stage, there are comments about sludge in reports between the Johoku Bridge andthe Matsushige Bridge. Because of low tide, sludge etc. might be easily raised up. And
this might be one of the reasons that “Color” and ”Smell” increased.

21

(2) Effect of TRWKR( No rain )Impression of Clearness from the 1st stage to the 5th stage
Sanage Bridge - Minatoshinbashi Bridge
0%

20%

40%

60%

80%100%4

All date
With TRWKR

48
2618
The rate of “Color”, “Smell” and “Transparency” changed.
472718
43 13 12

Without TRWKR①Color④Artificial gabage⑦Others55

20②Smell⑤Bubbling18

21 2③Transparency⑥Aspect of life

■ Are there any difference of the criterion for judgment of impression ofclearness whether TRWKR is done or not ?
The rate of “Color”, ”Smell” and ”Transparency” changed.
・①Color：With TRWKR＜Without TRWKR
・②Smell：With TRWKR＞Without TRWKR
・③Transparency：With TRWKR＞Without TRWKR
22

Column - The impression of Clearness and Analysis We explain the impression of clearness and analysis by 5th stage.
We considered that “Clear”, “Clear a little” and “Neutral” are permissible range of citizen. And wearranged the change of its rate by sampling point and stage. (ref. 1.1.(1))
The result showed that from the Sanage Bridge to the Matsue Bridge, the impression of clearness
in 5th stage improved more than in 1st stage. And the impression of clearness from spring to earlysummer was worse than from autumn to early winter.
Then we arranged results of researches whether TRWKR was done or not. When TRWKR wasdone, the impression of clearness is better at all section lower the Sanage Bridge. (ref. 1.1.(2))
We account for the criterion for judgment of impression of clearness. (ref. 1.2.(1))
The impression of clearness is mainly judged by “Color” and “Artificial garbage”. And theyaccount for 80%.
In the 5th stage, “Color” and ”Smell” increased. And there are comments about sludge in thereports between the Johoku Bridge and the Matsue Bridge. Because the tide was ebbed in 5th stage,sludge might be raised up easily. Then this might be one of the reasons that “Color” and “Smell”
increased.
We explain the criterion for judgment of impression of clearness whether TRWKR is done ornot.(ref. 1.2.(2))
When TRWKR is done, the rate of “Color”, ”Smell” and ”Transparency” changed. It will beshowed by the arrangement of Transparency, COD, Bubbling, color, smell and so on.
23