Horikawa Sen-nin Chosatai 2010th

Summary meeting for the 16 stage

The ｓecretariat of Horikawa Sen-nin Chosatai 2010
Feb.15th.2015

Photos：Goyousui-ato-gaien-aigokai
Survey Group
KawasemiSurvey Group１

Horikawa Sen-nin Chosatai 2010
～Transmission of Raw Water from
Kiso Riveｒ～
1.Purpose
To verify the clarification effects of TRWKR with
Citizens(1)Develop to new clarifying measures(2)Asses the influence on an ecosystem(3)Sustain and enhance citizens’ activities.
(4)Develop citizens’ awareness in the entire
Horikawa river basin
2.Water source and Volume of transmissionof raw water(1)Water source : Kiso River(2)Volume of transmisission of raw water:Maximum 0.4 m3/s
3.Pilot project period(1)Evaluation and Survey term : About 5 years（from Apr.2007 to Mar.2012）(Including the term of follow-up survey andevaluation after the stop of TRWKR)(2)TRWKR period : about 3years(from Apr.22nd 2007 to Mar.22nd 2010)■Increase of Transmisson Volume
from the Shonai River(additional pilot project）(1)Water Source Shonai River(2)Transmission Usual 0.4m3/sec (maxium 0.7m3/sec)(3)Experiment Period ：1st Oct-31St 2010(4)Period of Increased Transmision
Volume :Oct .5th-Nov.2nd 2010

The formation of HSC (April 22nd 2007)
With a viewpoint and a sence of citizens, the survey ofthe clarification effect of TRWKR started■ The survey from a view point and a sence of citizens＊Clearness ＊Transparency ＊Color ＊Smell＊Garbage ＊ Living things ,etc

The first Nagoya City Environmental practice Prize February.2012
Branch of contribution for Regional Environment Development
Award for excellence３

Transmission of Raw Water from Kiso River
3 years from April 22nd, 2007（Stopped on March 22nd,2010）
To verify the clarification effects of TRWKR
Surveys during TRWKR period :■ Role of the survey group
April 2007 ～ March 2010(Conclusions of Summary Meeting for the 10th Stage)
Surveys after the stop of TRWKR

Horikawa Sen-nin Chosatai
April 2007～March 2012

① More surveys should be implemented.
Continuity of investigation, Clarification of
the situation of the river, identification of
cause of pollution in the river, are needed.

■ Fixed Point Observation Groups
Surveying effects of TRWKR■ Free Survey Groups
Researching Horikawa River by free themes■ Horikawa Cheering Groups
Cheering clarification of Horikawa

We improve our plan and take action
against the pollution. After that, citizens
and public administration do what is
possible to clean the river.

To verify the clrification effectsof TRWKR

The survey from aview point and a
Ts ofsence of citizens■ It was confirmed that the water quality tended to improve
during TRWKR between Sanage Bridge and Matsushige
Bridge.
■ Network of citizens who wish for clarification andrestoration of Horikawa River expanded.
■ Citizens’ awareness of cleaning of the river wasdeveloped② There are many things that citizens cando. We expand our partners who love
Horikawa River and hope TRWKR again.
We deepen exchanges with people livingin the basin of Kiso, Nagara, and Ibi River.
We check the effects of pollution removalfrom domestic wastewater and implement
it in each house.

４Method of fixed-point observation
Transparency
Meter
100 cmMeasurement oftransparency

Photo: Shinko Survey Group

What is your
Impression of ・・・
cleanness?
Transparent?
Color?
Bubbles?
Smell?
Garbage?
Living things?

Yurinokai Survey Group
photo:Goyosui-ato-gaien-aigokai
Survey Group

Measurement of COD
Chemical Oxygen Demand. This is
an index of water contamination
used for sea, lakes and marshes.
It is an oxygen consumption
required for oxidation of organic
matters dissolved in ample water.
The higher COD, the more it iscontaminated.

COD pack test

５
Photo: Goyosui-ato-gaien-aigokai Survey GroupWater Environment of Horikawa River
Area of basin ：51.9km2
Length ：16.2km
Kiso River is our water source.

Change in temperature, precipitation and length of sunlight
Cause of breedingof phytoplankton,
nitorogen andphosphorus areincluded inwastewater fromhouses, factories
and stores.
It has looked like redtide or blue tide.
In Nagoya Port anddownstream ofHorikawa, it is said
that phytoplankton
does over breedingand extinction, so
water basin ispolluted
rad tide

The primary cause of water pollution is
wastwater from houses,factiories and stores.
Wastwater is discharged after treatment in wastwater treatment plant.
●●●

When heavy rain, wastewater isdischarged without treatment.

●●●

●●●

Shonai River
Provisional raw watertransmission ：0.3m3/s

●●●

●●●

●●●

Wastewater
Treatment Plant

Tide Gate▼high tide●●● ●●●Sanage Bridge

Motoiri Sluiceway

Horikawa▼ebb tide Difference of water level is more than 2m between high tide and edd tide.
Water level, direction of current and velocity are changed by tide.
Nagoya Port

Shimizu wakuwaku-sui

risingGround water etc

Ise bay
Sludge rises and floats.
blue tide

floating sludge

raised sludge

６Investigation spots

Network of citizens who wish forclarification and restoration ofHorikawa River is growing.

Number of Participants of Horikawa
Sen-nin Chosatai 2010
(Horikawa Sen-nin Chosatai started
accepting participation on 26th Mar .2007)

Start

Now

22nd Apr.2007

15ｔｈ Feb.2014

Fixed Point
Observation
Groups55 groups
497persons

95 groups
980persons

Free Survey
Groups22ｇroups
234persons

40 groups
650persons

Horikawa
Cheering
Groups88ｇroups
1,531persons

2,541 groups
51,475persons

Total

165ｇroups
2,262persons

2,676 groups
53,105persons

７

Number of Participants ofHorikawa Sen-nin Chosatai
Growth of participants
60,000

定点観測隊

55,000

応援隊

全隊

第11ステージ

第13ステージ

Total 53,105 persons

50,000

Fixed Point Observation Group 980 persons

45,00040,000Free Survey Groups 650 persons
Horikawa Cheering Groups 51,475 persons

35,00030,00025,000

第1ステージ

第3ステージ

第2ステージ

第5ステージ

第4ステージ

第7ステージ

第6ステージ

第9ステージ

第8ステージ

第10ステージ

第12ステージ

第15ステージ

第14ステージ 第16ステージ

20,00015,00010,000
5,000
0
H19.4
H19.6
H19.8
H19.10
H19.12
H20.2
H20.4
H20.6
H20.8
H20.10
H20.12
H21.2
H21.4
H21.6
H21.8
H21.10
H21.12
H22.2
H22.4
H22.6
H22.8
H22.10
H22.12
H23.2
H23.4
H23.6
H23.8
H23.10
H23.12
H24.2
H24.4
H24.6
H24.8
H24.10
H24.12
H25.2
H25.4
H25.6
H25.8
H25.10
H25.12
H26.2
H26.4
H26.6
H26.8
H26.10
H26.12
H27.2

Number of Participants

自由研究隊

Month and Year
September 15th .2015

８

Survey Period and Number of Reports
Number ofReports
Spring - Early Summer / Apr. 22nd - Jun. 30th. 2007
258
Jul. 1st - Sep. 7th. 2007
134
Autumn - Early Winter / Sep. 8th -Dec. 16th. 2007
383
Dec. 17th - Mar. 31st. 2008
103
Spring - Early Summer / Apr. 1st - Jun. 30th. 2008
245
Jul. 1st - Sep. 27th. 2008
64
Autumn - Early Winter / Sep. 28th -Dec. 16th. 2009152
Dec. 17th. 2008 - Mar. 31st. 2009100
Spring - Early Summer / Apr. 1st - Jun. 30th. 2009
145
Jul. 1st - Sep. 26th. 200954
Autumn - Early Winter / Sep. 27th -Dec. 16th. 2009120
Dec. 17th. 2009 - Mar. 31st. 201081
Spring - Early Summer / Apr. 1st - Jun. 30th. 2010
111
Jul. 1st - Sep. 11th. 200744
Autumn - Early Winter / Sep. 12th -Dec. 17th. 2010
104
Dec. 18th. 2010 - Mar. 31st. 201172
Spring - Early Summer / Apr. 1st - Jun. 30th. 2011112
Jul. 1st - Sep. 10th. 201142
Autumn - Early Winter / Sep. 11th -Dec. 16th. 2011133
Dec. 17th. 2011 - Mar. 31st. 201277
Spring - Early Summer / Apr. 1st - Jun. 30th. 2012148
Jul. 1st - Sep. 21th. 201260
Autumn - Early Winter / Sep. 22th -Dec. 16th. 2012139
Dec. 17th. 2012 - Mar. 31st. 201392
Spring - Early Summer / Apr. 1st - Jun. 30th. 2013
145
Jul. 1st - Sep. 28th. 201370
Autumn - Early Winter / Sep. 29th -Dec. 17th. 2013
113
Dec. 18th - Mar. 31st. 201479
Spring - Early Summer / Apr. 1st - Jun. 30th. 2014133
Jul. 1st - Sep. 7th. 201491
Autumn - Early Winter / Sep. 28th -Dec. 16th. 2014
99
3,703

Survy Period

With TRWKR

Introduction of advanced water
treatment at the Meijo Water
Treatment Center
In-service of Horikawa
Ugan Rain-Water Reservoir
for pollution control
Utilization of reclaimed
wastewater from Moriyama
Water Treatment Centerfrom Apr. to Oct.

Total

1st stageinterval
2nd stageinterval
3rd stageinterval
4th stageinterval
5th stageinterval
6th stageinterval
7th stageinterval
8th stageinterval
9th stageinterval
10th stage
interval
11th stage
interval
12th stage
interval
13th stage
interval
14th stage
interval
15th stage
interval
16th stage

９

Number of Reports

The total number of reports about survey is 3,703 by the end of the16th stage.
On average, it is 400 every year.
A lot of citizens survey the real state of water environment of Horikawa River continuallyfrom a viewpoint and sense of citizens.

１０

４．Weather Condition
In Sep. 2014, there were more sunny days by migratory anticyclone, so length of sunlight was longer
and precipitation was lower. Temperature was lower due to cold air mass.
In Oct. two typhoons (Phanfone and Vongfong)hit Honshu and the precipitation got higher.
In Nov. and Dec., weather changed in every few days by high and low pressure. In some days after low
pressure passed, the atmospheric pressure chart pattern was typical of winter and temperature changed
lower by the effect of cold air mass. Just after the 16th stage, it snowed in the plain area.

To Sum up the weather condition in 16th stage (Sep.-Dec. 2014),
precipitation was a little more than normal, while temperature and length ofsunlight was almost same as normal.
average value (Nagoya Local Meteorological Agency)

16th stage(Sep.-Dec. 2014)■ Temperature
Average temperature was 15.2℃, almost same as thenormal(15.4℃)■ Precipitation
Average precipitation was 136mm/month , a little morethan usual. (121.9mm/month)■ Length of sunlight
Average hours of sunlight was 166 hrs./month, almost
same as the normal(163.7hrs./month).

気温
降水量
temperature
precipitation
(℃)
(mm)
total
average
max.
合計
平均
最高

min..
最低

lengthof
日照時間
sunlight
(時間)
total
合計

period
統計期間

1981
～2010

1981
～2010

1981
～2010

1981
～2010

1981
～2010

years
資料年数
April4月
May5月
June
6月
Average
平均
9月
September
10月
October
11月
November
12月
DecemberAverage
平均

30
143.3
155.7
201.5
166.8
234.4
128.3
79.7
45.0
121.9

30
14.1
18.5
22.3
18.3
24.1
18.1
12.2
7.0
15.4

30
19.5
23.7
26.7
23.3
28.6
22.8
17.0
11.6
20.0

30
9.2
14.0
18.7
14.0
20.7
14.1
8.1
3.1
11.5

30
188.4
199.6
145.2
177.7
151.0
169.0
162.7
172.2
163.7

区分
sectionJapan Meteorological
Agency, weather statistics
information
資料：気象庁_気象統計情報
名古屋地方気象台
at Nagoyahttp://www.jma.go.jp/jma/menu/report.html
Local Meteorological Agency
http://www.jma.go.jp/jma/menu/report.html

11Japan Meteorological Agency, weather statistics information
資料：気象庁_気象統計情報
名古屋地方気象台
at Nagoya
Local Meteorological Agency
http://www.jma.go.jp/jma/menu/report.html
http://www.jma.go.jp/jma/menu/report.html

Temperature
Spring to Early Summer(Apl. - Jun.)
40
30
25
20

10th stage, 2011

average temperature over 30 years of 3monthes(Apr.-Jun.)
18.3℃

18.7

19.1

19.5

18.6

18.7

18.6

18.9

14th stage, 20135
15th stage

13th stage

11th stage

9th stage

7th stage

5th stage

3rd stage

0

Average Temperature(℃)

10Autumn to Early Winter(Sep. - Dec.)

15

10After the stop ofTRWKR
Average 15.8℃

With TRWKR
Aerage 16.0℃

35
30
25
20

average temperature over 30 years of 3monthes(Sep.-Dec.)
15.4℃

16.4

15.9

15.8

16.4

16.1

15.4

15.8

5

15.2

15

0
9/1

10
5

16th stage, 2014

20

40

In Sep, temperature waslower due to cold air mass.

In Dec., weather changed every
few days by high and low
pressure. In some days after low
pressure passed, the atmosphericpressure chart pattern was
typical of winter and temperaturechanged lower by the effect ofcold air mass.

10/1

11/1

12/1

16th stage

14th stage

12th stage

10th stage

8th stage

6th stage

4th stage

0
2nd stage

Average Temperature(℃)

12th stage, 2012

25

19.4

15

1st stage

Average Temperature(℃)

3530After the stop of TRWKR
Average 18.8℃

With TRWKR
Average 19.1℃

Average temperature of 16th stage was 15.2℃,
almost same as the normal (15.4℃).

12Precipitation
Spring to Early Summer(Apl. - Jun.)
300
250

213

203

204

200

average precipitation
185 over 30 years of 3monthes(Apr.-Jun.)
166.8mm/month

150

123

133

114

118

50
15th stage

13th stage

11th stage

9th stage

7th stage

5th stage

3rd stage0

precipitation(mm/day)100

1st stage

Average precipitation(mm/month)after the stop of TWRKR
average 155mm/monthWith TRWKR
average173mm/monthprecipitation(mm/day)Japan Meteorological Agency, weather statistics information
at Nagoya Local Meteorological Agency
http://www.jma.go.jp/jma/menu/report.html

10th stage, 2011200

10th stage:
Sep.11- Dec. 16
Sep.19-21:typhoon Roke
3days total 274mm

150
100
50
0
9/1
200

150

average precipitation over 30 years of 3monthes(Sep.-Dec.)
121.9mm/month
157
156
136
130
127
122

100

79

200

84

Average precipitation of 16th stage (Sep.Dec.) was 136mm/month, a little less thannormal (121.9mm/month).

16th stage

14th stage

12th stage

10th stage

8th stage

6th stage

4th stage0

precipitation(mm/day)50
2nd stage

Average precipitation(mm/month)250

precipitation(mm/day)With TRWKR
average 98mm/month

12/1
12th stage:
Sep.22 -Dec. 16

Sep. 30:typhoon Jelawat,
92.5mm/day

150
100
50

Autumn to Early Winter(Sep. - Dec.)
after the stop of TWRKR
average 140mm/month

11/1

12th stage, 2012

0
9/1

300

10/1

200
150

10/1

11/1

12/1

14th stage, 2013
Sep. 4:many places in Nagoya
14th stage:
Heavy rain of 100mm/hour or more
Sep. 29 - Dec. 17
73mm at Nagoya Meteorological Agency

Sep. 16:typhoon Man-yi,101mm/day

100

Oct.15, 16:typhoon Wipha
2days total 113.5mm

50Oct. 20: rain front
83mm/day

0
9/1

11/1

12/1

16th stage, 2014

200
150

10/1

Sep. 25: low pressure system
and rain front, 86.5mm/day
・Submerged at Nagoya Station

100

16th stage:
Sep. 27 - Dec.17

Oct. 3th:typhon Vongfong, 60mm/day

50
0
9/1

10/1

11/1

12/1

13

Japan Meteorological Agency, weather statistics information
at Nagoya Local Meteorological Agency
http://www.jma.go.jp/jma/menu/report.html

Spring to Early Summer
500
450
400
350
300
250
200
150
100
50
0

With TRWKR
average 197hours/month(Apl.- Jun.)

15

after the stop of TRWKR
average 193hours/month

10

209

175

207

187

208

173

173

5
0
9/1

10/1

11/1

12/1

12th stage, 201215

12th stage:
Sep.22 -Dec. 16

15th stage

13th stage

11th stage

9th stage

7th stage

5th stage

3rd stage

10
5
0
9/1

Autumn to Early Winter(Sep.- Dec.)

10/1

10
5
0
9/1

10/1

16th stage

14th stage

12th stage

10th stage

8th stage

11/1

12/1

16th stage, 201415
6th stage

12/1

14th stage:
Sep. 29 - Dec. 17

average hours of sunlight over 30 years of 3monthes(Sep.-Dec.)
Average 163.7 hours/month
183
178
177
173
171
166
161
144

Average length of sunlight was 166 hrs./month,almost same as normal(163.7hrs./month).

11/1

14th stage, 201315

after the stop of TWRKR
average 174hours/monthWith TRWKR
average161hours/month

4th stage

500
450
400
350
300
250
200
150
100
50
0

2nd stage

average length of sunlight(hours/month)

10th stage, 2011
10th stage:
Sep.11- Dec. 16

average precipitation over 30 years of 3monthes(Apr.-Jun.)
Average 177.7 hours/month225

1st stage

average length of sunlight(hours/month)

Length of Sunlight

16th stage:
Sep. 27 - Dec.17

10
5
0
9/1

14
10/1

11/1

12/1

５．Main Measures for Water Quality Improvement
Measuresfy. 2007

fy. 2008

fy. 2009

fy. 2010

fy. 2011

fy. 2012

fy. 2013

fy. 2014

1st.

3st.

5st.

7st.

9st.

11st.

13st.

15st.

2st.

4st.

6st.

8st.

10st.

12st.

14st.

16st.

3

With TRWKR(0.4m /s)
Build a deep and shallow zone
（Improvement of self-purification function
and water enironment)
Increase of raw water transmission from the3

Shonai River(＋0.4m /s)

Utilization of shallow ground water(0.0405m3/s)
Experiment of covering sand for water purification
Gojo Brdg.-Naka Brdg.（water's edge along bothbanks）

Introduction of Advanced water treatment at the
Meijo Water Treatment Center
In-service of the Horikawa Ugan Rain-water
Reservoir for pollution control
Utilization of reclaimed wastewater at Moriyama
3

Water Treatment Center(0.046m /s)

Newly launched facilities after the stop of TRWKR■For improvement of quality of treated water(Additional filtration of treated water at the
Meijo Water Treatment Center can improve
quality of water discharging into Horikawa
River )

Advanced water treatment
at Meijo Water Treatment Center
Solution : conventional activated sludge
process and rapid filtration
Launch : May. 2010

■For improvement of combined sewer system(Storing first flush with high pollution load torestrain outflows temporarily)

The Horikawa Ugan Rain-water
Reservoir for pollution control
Volume : 13,000m3
Coverage Area : 633ha
Launch : Sep. 2010

Construction of water storage facility for
improvement of combined sewer system
Legendcompleted
under construction

15

Newly launched facilities after the stop of TRWKR■Securement of Additional Water Resource■Utilization of shallow ground waterin the upstream of Horikawa

Utilization of Reclaimed wastewater
Conducting reclaimed wastewater
treated by membrane filtration at theMoriyama Water Treatment Center(up to 4000m3/day) is discharged
Start to conduct in Aug. 2011

Moriyama Water
Treatment Center
Newly installed
pipeline

Upstream from Sanage Bridge 0.01㎥/s
Shonai
Irrigation
Conducting point into
Horikawa River
Reclaimed wastewater is conductedduring irrigation season (Apr - Oct)

■Form◆瀬淵の形成
of shallow and deep spot

Discharge of shallow ground water
total 0.0405m3/s

Horikawa
River
Reference：
10th Horikawa Sennin Chosatai conference

Downstream from Kurokawa No.2 Bridge
Sep. 2013
Various living things
come to this place
for growing andbreeding.

Reference：
10th Horikawa Sennin Chosatai conference

New water source isreclaimed wastewater(from Apr. to Oct.) andshallow ground water.
Volume is 0.0865m3/s,
almost same as filling
water in a bathtub in 2
secs.

Upstream from Sanage Bridge
Discharge 0.01m3/s
Start Aug. 201416

Column“To clarify and restore the Horikawa River”
Horikawa Sen-nin Chosatai 2010 was made as a place for citizens’ activities to clarify and restore
Horikawa River on April 22nd, 2007.
There are 95 Fixed Point Observation Groups which continuously investigate real state of water
quality, and cause of pollution. And there are also 40 Free Survey Groups and 2,541 Horikawa
Cheering Groups. There are 53,105 persons on a list on Feb 15, 2015.
The fixed point observations had been carried out 3,703 times by the end of the 16th stage. They
turned out what makes citizens’ impression about water quality of the Horikawa River.
Pilot project for clarification of the Horikawa River (from April 2007 and March 2012)
The pilot project of TRWKR (Transmission of Raw Water from the Kiso River) improved water quality
between Sanage Bridge and Matsushige Bridge.
After TRWKR stopped, advanced water treatment at the Meijo Water Treatment Center
was introduced and the Horikawa Ugan Rain-water Reservoir was launched.
Moreover, reclaimed wastewater treated by membrane filtration at the Moriyama Water
Treatment Center was discharged into the Horikawa River.

１7

■Change of water quality (Impression of water clearness, Transparency, COD)
After the stop of TRWKR (May 2010), an advanced water treatment introduced at Meijo treatment center in
May 2010, and the Horikawa Ugan rain-water reservoir for pollution control has been in service since Sep
2010. The securement of additional water resource such as reclaimed waste water from the Moriyama water
treatment center and shallow ground water, has been proceeding. Although water quality worsened in 7th and8th stage (2010 just after the stop of TRWKR), we see improvement little by little from Sanage Bridge to Asahi
Bridge recently. Therefore we consider that water quality in surface has been improved by measures forwater quality introduced after the stop of TRWKR. We need to continue to collect and organize the data to get
the change of water quality and its mechanism.
Just after the stop of TRWKR

Effect of water quality
improved measures

Flesh water
Salt water

Flesh water quality improves
Improved range expands todown stream①advanced water treatment at the
Meijo treatment center②the Horikawa Ugan rain-water
reservoir for pollution control③The securement of additional
water resource, such as reclaimed
waste water from the Moriyama
water treatment center and shallow
ground water

Bottom layer range improves
synergistically. Self purification
Function recovers.

④Recovery of self purification
Function.

After the introductionof advanced water treatment
fresh water quality improved

We will be able to catch thesmall improvement of
Horikawa by water quality
improve measures.

Salt water

18

■Bubbles and Smell
Occurrence of bubbles and smell decreased recently compared to those of just after the stop of TRWKR.
Especially the ratio of “Terrible smell” of 15th and 16th stage were improved to half of the ratio of 7th and8th stage. According to the results, the ratio of “terrible smell – smell” is 44% when bubbles from riverbed
occurred. Smell seems worse when bubbles from riverbed are seen.
Especially from Asahi Bridge to Matsushige Bridge, we find the relation between them. Now we consider themeasures for water quality contribute to the improvement of occurrence of Bubbles and Smell. But we can’t
explain these facts because data is not enough. In line with our hypothesis described in “Change of water
quality (Improve of clearness, Transparency, COD)” chapter, Bottom sediment might has been improved little
by little for long time by water quality improvement. We need to continue to collect and organize the data to
get the change of bubbles, smell and this mechanism.

■Change of living things
Although Horikawa was called “Dead River” due to sludge deposition in 1960s, its water quality has been
improving. Besides, 16 kinds of fish, 4 kinds of crustaceans and 33 kinds of birds have been witnessed.
Horikawa’s ecosystem is returning to its former state. We consider this is a sign that Horikawa’s selfpurification function is recovering.
From Horikawa clean experiments of Chinese Water Spinach by Ena Agricultural Highschool and Horikawa Lions
Club, many living things were seen in an experiment field.
According to this experiment, many living things can live in Horikawa when the edge of water conditions isgood. Horikawa is getting back to its former state.

Horikawa in 1960s

Horikawa in 1980s

20

Many living things can live in Horikawa when the edge ofwater conditions is good.

■Naya Brdg

experiments of Chinese water spinach

During the experiment

Befor the experiment■Naka Brdg～Gojo Brdg
water purification experimentby sand covering

During the experiment

Befor the experiment21

■Total lunar eclipse (Oct.8th, 2014)
When solar or lunar eclipses occur, the sun, the moon and the earth are in a straight. And the force of
attraction becomes stronger, which causes spring tide. HSC investigated what happened in Horikawa during
spring tide in July 2009 (partial solar eclipse) and May 2012(total lunar eclipse). As a result, blue and red
tide appeared on the mid-stream, and the tide rolled up sludge. We got a clue to find the mechanism of thisphenomenon. In this total solar eclipse(Oct.8th, 2014) we saw tide rolling up sludge from Asahi Bridge to
Matsushige Bridge. And we saw floating particles accumulated on the surface from Sakura Bridge to NayaBridge. But blue tide, red tide and bubbles from riverbed were not seen. While striped mullet (Bora) seem not
to have difficulty in breathing. This is because, we consider, blue and red tide rarely occur in autumn, or
because sea water in downstream was replaced by heavy rain (60mm) due to typhoon.

Comparison of simultaneous investigation during eclipse
State of Horikawa
blue tide and red tide
area

partialeclipseJul-09annulareclipseMay-12

Sanage biridge Johoku bridge-

Johoku bridge Asahi bridge

-

total
eclipseOct-15

partialeclipseJul-09sludgeannulareclipseMay-12other changes

total
eclipseOct-15

partialeclipseJul-09○○Asahi bridge Matsushige bridge blue tide○
red tide-Matsushige bridge- Ooseko biridge○
red tide-○

5th Horikawa investigation–spring big tide investigations
20th Apr 2015

○

-

○

○

-

-

○

partialeclipseJul-09creatureannulareclipseMay-12

total
eclipseOct-15floating litterspartialannulartotal
eclipse eclipse eclipse
Jul-09
May-12 Oct-15

-

-

○

-

○

-

To make sure our Hypotheses,
We hold 5th investigation –spring big tide investigationsLet’s survey what happened inHorikawa

・Nagoya port tidal level difference is big：over 240cm
・We could see blue tide, red tide and bubbles fromriverbed

total
eclipseOct-15○--bubblesannulareclipseMay-12--○mullet *-○mullet--○mullet* breath with difficulty○
Tenma Nayabridge--○Tenma Nayabridge○Tenma Nayabridge--

HSC Hypotheses

11th meeting
・Mechanism of red and blue tide・Movement of anoxic water
13th・Current condition and pollution mechanismof Horikawa
14th・the improvement of water quality and sludge on
the riverbed of Horikawa
・the reason of increasing dark color in 14th stage

22

The 1st-6th stage ： With TRWKRNo rain on the day and the previous day
The 7th-16th stage： No TRWKR
The ratio of “Clean”, “Slightly clean” and “Ordinary” No rain on the day and the previous dayNote） Not enough data.

6.2. Impression of Water Clearness
Upstream Section（Between Sakae Brdg. and Sanage Brdg. _ Average）
With TRWKR
Introduction of advanced water treatment at Meijo Water Treatment Center
In-service of Horikawa Ugan Rain-water Reservoir for pollution control

水の汚れの印象（％）
Impressionof Water Clearness(%)

25 out of 31 times surveys were carried out on June 27th
(at Kizune Bridge), and “Slightly dirty” was seen a lot.
100

100

Utilization of reclaimed wastewater at Moriyama Water Treatment Center
Between Sakae
Brdg.
Utilization of groundwater
栄橋～猿投橋間and Sanage Brdg.
100
100
100
100
100
100
100
100

93
87

87
75

80
60

60

40

50

Horikawa upstream section is mostly
in the acceptable range for citizens

39

20(The ratio of “Clean”, “Slightly clean” and “Ordinary” is mostly 100%)

H23.4.1～6.30

第7st.
5

第8st.
8

第9st.
5

Note） Not enough data.

H26.9.29～12.16

H22.9.11～12.17

第6st.
3

H26.4.1～6.30

H22.4.1～6.30

第5st.
8

H25.9.29～12.17

H21.9.27～12.16

第4st.
2

H25.4.1～6.30

H21.4.1～6.30

第3st.
15

H24.9.22～12.16

H20.9.28～12.16

第2st.
41

H24.4.1～6.30

H20.4.1～6.30

第1st.
31

H23.9.11～12.16

H19.9.8～12.16

Numberof data

H19.4.22～6.30

0

第10st. 第11st. 第12st. 第13st. 第14st. 第15st. 第16st.
9
1
9
7
8
8
7

■ How did the impression of water clearness change in Horikawa upstream section(between Sakae Brdg. and Sanage Brdg.)?
→Although we don’t have enough data, the ratio of water clearness impression changes mostly in theacceptable range for citizens.
＊“Clean”, “Slightly clean” and “Ordinary” are categorized as the acceptable range for citizens.

23

The 1st-6th stage ： With TRWKRNo rain on the day and the previous day*
The
7th-16th stage： No TRWKR
The ratio of “Clean”, “Slightly clean” and “Ordinary”
No rain on the day and the previous day

Impression of Water Clearness

Middle andNote）Except the data between Oseko Brdg. and Minatoshin Brdg. for not enough data
Downstream Section（Between Sanage Brdg. and Oseko Brdg. _ Average）
With TRWKR
Introduction of advanced water treatment at Meijo Water Treatment Center
In-service of Horikawa Ugan Rain-water Reservoir for pollution control
Between Sakae

Utilization of reclaimed wastewater at Moriyama Water Treatment CenterBrdg.
猿投橋～大瀬子橋間

Utilization of groundwater

Impressionof Water clearness(%)
水の汚れの印象（％）

and Oseko Brdg.
100

With TRWKR
Improved

80

No TRWKR
Worsened

59

60

Increasing occurrence of
bubbles and smell,
Going upstream of red
tide and blue tide,Winding
up of sludge→Worsened

45

43

42

20

Improved

43

40
29

According to the survey,
the acceptable range forcitizens(“Clean”, “Slightly
clean” and “Ordinary”) is
58%.
58

32

29

24
18

16

22

31

24

9

63

第7st.

85

第8st.

67

第9st.

H26.9.29～12.16

H26.4.1～6.30

H25.9.29～12.17

H25.4.1～6.30

第6st.

111

H24.9.22～12.16

第5st.

52

H24.4.1～6.30

H21.9.27～12.16

第4st.

176

H23.9.11～12.16

H21.4.1～6.30

第3st.

208

H23.4.1～6.30

H20.9.28～12.16

第2st.

113

H22.9.11～12.17

H20.4.1～6.30

第1st.

H22.4.1～6.30

H19.9.8～12.16

Numberof data

H19.4.22～6.30

0

第10st. 第11st. 第12st. 第13st. 第14st. 第15st. 第16st.

76

113

113

98

93

81

89

■How did the impression of water clearness change in the middle and downstream of Horikawa River (between Sanage Brdg. and Oseko Brdg.)?
→Improving trend was seen (the ratio of “Clean”, “Slightly clean” and “Ordinary” was increased) during TRWKR. In the 7th stage after the stop of TRWKR,
impression of water clearness was worsened. Moreover, in the 12th and 13th stage, it was worsened by increasing occurrence of bubbles and smell, going
upstream of red tide and blue tide, and winding up of sludge. However, impression of water clearness was improved after that. It is considered that these trends
are made by the effect of new water quality improvement measures. The ratio of “Clean”, “Slightly clean” and “Ordinary” was 58% in the 16th stage.
＊“Clean”, “Slightly clean” and “Ordinary” are categorized as the acceptable range for citizens.

24

Impression of Water Clearness（Section Average）

The 1st-6th stage ： With TRWKRNo rain on the day and the previous day
The 7th-16th stage： No TRWKRNo rain on the day and the previous day

The ratio of “Clean”, “Slightly clean” and “Ordinary”
Note）Except the data between Minatoshin Brdg. and Oseko Brdg.
for not enough data

With TRWKR

Introduction of advanced water treatment at Meijo Water Treatment Center
In-service of Horikawa Ugan Rain-water Reservoir for pollution control
Utilization of reclaimed wastewater at Moriyama Water Treatment Center
Utilization of groundwater(Evaluation
Section)

Unit：％

Btwn. Sakae Brdg.
and Sanage Brdg.
（Not enough data）

60

100

100

100

100

80

80

80

60

80
60

40

Btwn. Sanage Brdg.
and Johoku Brdg.
Btwn. Johoku Brdg.
and Asahi Brdg.
（Not enough data）

60

40

40

20

40

40

20

40

20

40

20

After the stop of TRWKR→Worsened 10

40

20

10

60
40

20

Increasing occurrence of
bubbles and smells,
Going upstream red tideand blue tide,Winding up
of sludge →Worsened
40

40

20

20
60

60

20

10

With TRWKR→Improved

Btwn. Asahi Brdg.
and Matsushige Brdg.

Btwn. Matsushige
Brdg.
and Oseko Brdg.

40

With new water quality
improvement measures
80→Improved

40

20

20
40

第1st. 第2st. 第3st. 第4st. 第5st. 第6st. 第7st. 第8st. 第9st. 第10st. 第11st. 第12st.第13st. 第14st. 第15st. 第16st.
％（Dirty）％（Clean）＊“Clean”, “Slightly clean” and “Ordinary” are categorized as the acceptable range for citizens.

We think impression of water clearness has gradually improved mainly between Sanage Brdg. andAsahibashi Brdg. It is considered that these trends are made by the effect of new water quality
improvement measures

25

The 1st・3rd・5th stage ： With TRWKRNo rain on the day and the previous day
The 7th・9th・11th・13th・15th stage ： No TRWKRNo rain on the day and the previous day

Impression of Water Clearness(Section Average)
From Spring to Early Summer
The ratio of “Clean” , “Slightly Clean” and “Ordinary”*

Numberof data

Improved

37

42

30

24

20

27

16

16

Impression of Water Clearness(%)

Impression of Water Clearness(%)

Improved between Sanage Brdg. and Matsushige Brdg.

Numberof data

Improved

46

82

37

25

12

14

13

6

9

14

7

5

35

34

Impression of Water Clearness(%)

Impression of Water Clearness(%)

Numberof data

Improved

43

Occurrence of Smell ,Bubbles,
Red tide, Rising sludge→Deteriorated

Occurrence of Smell ,Bubbles,
Red tide, Rising sludge→Deteriorated

Note） Not enough data

22

Numberof data

15

33

29

30

25

The impression of water clearness in the 15th stage has improved between Sanage Brdg. and Matsushige Brdg. compared withjust after the stop of TRWKR(the 7th stage).
The ratio of “Clean”, “Slightly clean” and “Ordinary” was higher in the upstream area. The ratio between Sanage Brdg. andJohoku Brdg. was over 50%. On the other hand, the ratio between Matsushige Brdg. and Oseko Brdg. was less than 10%.

27

35

34

27

The 2nd・4th・6th stage ： With TRWKRNo rain on the day and the previous day
The 8th・10th・12th・14th・16th stage ： No TRWKRNo rain on the day and the previous day

Impression of Water Clearness(Section Average)
From Autumn to Early WinterThe ratio of “Clean” , “Slightly Clean” and “Ordinary”*

Improved between Sanage Brdg. and Matsushige Brdg.
Impression of Water Clearness(%)

Impression of Water Clearness(%)

Improved

Numberof data

47

11

17

16

23

20

17

11

Numberof data 103

28

16

25

43

Occurrence ofSmell ,Bubbles, Blue tide,→Deteriorated

40

25

29

Occurrence ofSmell ,Bubbles, Blue tide,→Deteriorated

Numberof data

Impression of Water Clearness(%)

Impression of Water Clearness(%)

Improved
Note） Not enough data

21

2

4

5

12

12

11

6

Numberof data

35

9

25

21

35

26

The impression of water clearness in the 16th stage has improved between Sanage Brdg. and Asahi Brdg. compared with justafter the stop of TRWKR(the 8th stage).
The ratio of “Clean”, “Slightly clean” and “Ordinary” between Sanage Brdg. and Asahi Brdg. was over 60%.

28

16

28

The 1st・3rd・5th stage ： With TRWKRNo rain on the day and the previous day
The 7th・9th・11th・13th・15th stage ： No TRWKRNo rain on the day and the previous day

Utilization of shallow groundwater

Utilization of reclaimed wastewater atMoriyama Water Treatment Center

In-service of Horikawa Ugan Rain-water
Reservoir for pollution control

Introduction of advanced water treatment
at Meijo Water Treatment CenterWith TRWKR

Evaluation of Impression of Water Clearness
From Spring to Early Summer

Note） 0% items are not displayed.

■ How did the evaluation of impression water clearness change?
→High ratio items of the water clearness evaluation were “Color”.
In comparison with just after the stop of TRWKR(the 7th stage), the ratio of “Transparency” has increased andthat of “smell” and “Garbage” has decreased in the 15th stage. in particular , the ratio of “Transparency” was
29% , the ratio of “Smell” was 3%, the ratio of “Garbage” was 7% .

29The 2nd・4th・6th stage ： With TRWKRNo rain on the day and the previous day
The 8th・10th・12th・14th・16th stage ： No TRWKRNo rain on the day and the previous day

Utilization of shallow groundwater

Utilization of reclaimed wastewater atMoriyama Water Treatment Center

In-service of Horikawa Ugan Rain-water
Reservoir for pollution control

Introduction of advanced water treatment
at Meijo Water Treatment CenterWith TRWKR

Evaluation of Clearness of Impression Water
From Autumn to Early WinterNote） 0% items are not displayed.

■ How did the evaluation of impression of water clearness change?
→High ratio items of the water clearness evaluation were “Color” and “Transparency” .
In comparison with just after the stop of TRWKR(the 8th stage),
the ratio of “color” and “Transparency” were almost equal in the 16th stage.

30

Evaluation of Impression of Water Clearness
From Spring to Early Summer Between Sanage Brdg. and Minatoshin Brdg.
Introduction of advanced water treatment at Meijo Water Treatment CenterWith TRWKR

In-service of Horikawa Ugan Rain-water Reservoir for pollution control

The 1st・3rd・5th stage ：With TRWKRNo rain on the day and the previous day
The 7th・9th・11th・13th・15th stage ：No TRWKR
No rain on the day and the previous day

Utilization of reclaimed wastewater at Moriyama Water Treatment Center
Utilization of groundwater

The criterion for evaluation when people answered “Clean”, “Slightly clean” and“Ordinary”.

■ What is the item to evaluate

With TRWKR“Clean”, “Slightly clean” and“Ordinary”?
→“Transparency” has increased
and accounted for about 72% in
the 15th stage.

The evaluation of “Transparency”
has increased.

No data

Numberof data

47

33

9

14

27

19

18

“The criterion for evaluation when people answered “Slightly dirty” and “Dirty”.

■ What is the item to evaluate“Slightly dirty” and “Dirty”?
→“Color” has increased andaccounted for about 70% in 15thstages.

With TRWKRThe evaluation of “color”
has increased.

No data

Numberof data

127

77

75

61

86

73

69

Note） 0% items are not displayed.

31

Evaluation of Impression of Water Clearness
From Autumn to Early Winter Between Sanage Brdg. and Minatoshin Brdg.
Introduction of advanced water treatment at Meijo Water Treatment CenterWith TRWKR

In-service of Horikawa Ugan Rain-water Reservior for pollution control

The 2nd・4th・6th stage ：With TRWKRNo rain on the day and the previous day
The 8th・10th・12th・14th・16th stage ：No TRWKR
No rain on the day and the previous day

Utilization of reclaimed wastewater at Moriyama Water Treatment Center
Utilization of groundwater

The criterion for 木曽川からの導水
evaluation when people answered “Clean”, “Slightly clean” and“Ordinary”.
With TRWKR■ What is the item to evaluate“Clean”, “Slightly clean” and“Ordinary”?
→“Transparency” has increasedslightly and accounted for about
51% in the 16th stage.

The evaluation of “Transparency”
has increased.
Numberof data

91

31

27

31

49

20

27

31

“The criterion for evaluation when people answered “Slightly dirty” and “Dirty”.
With TRWKR■ What is the item to evaluate“Slightly dirty” and “Dirty”?
→“Color” has increased slightly
and accounted for about 56% in
16th stages.

The evaluation of “color”
has increased.
Numberof data

104

21

36

36

63

77

54

31

Note） 0% items are not displayed.

32

The 7th・15th stage ：Evaluation of Impression of Water Clearness
No TRWKR…Compared with the 7th stage and the 15th stage No rain on the day and the previous day

The evaluation of “Transparency”
has increased.

Note） Not enough data

The evaluation of “Transparency”
has increased.

The ratio of “Transparency” in the 15th stage has increased between Sanage Brdg. and Asahi Brdg.
compared with just after the stop of TRWKR(the 7th stage).

33

The 8th・16th stage ：Evaluation of Impression of Water Clearness
No TRWKRthth
No rain on the day and the previous day…Compared with the 8 stage and the 16 stage

The evaluation of “Transparency”
has increased.

The evaluation of “Transparency”
has increased.

Note） Not enough data

The ratio of “Transparency” in the 16th stage
has increased between Sanage Brdg. andJohoku Brdg. and also between Asahi Brdg.
and Matsushige Brdg. compared with just after
the stop of TRWKR(the 8th stage).

In the 15th stage and the 16th stage ,the ratio of “Transparency” has increased between
Sanage Brdg. and Johoku Brdg. in the middle anddownstream section.

34

２． Change in Transparency
Measuring transparency（Reference） The 9th survey meeting
Relationship between the Impression of Water Clearness
and the Average of Transparency
The 2nd-9th stage (No rain) : Including out-of period data
Water clearness impression is evaluated by translucency
in the all sections(including upstream section)

Photo: Shinko Survey Group

透視度(cm)、透明感で評価

Photo: Goyousui-ato-gaien-aigokai
Survey Group

Transparency(cm) _ Evaluated by translucency

Relationship 水の汚れの印象と透視度(透明感）の関係
between Water Clearness Impression and Transparency“Clean”, “Slightly clean” and “Ordinary” arecategorized as the acceptable range for citizens.

100

86

82
72

80
60

65

63

Over 70cm
transparency

40

y = -6.3x + 92.5
R2 = 0.9606

20
0
0

1
きれい
Clean

Slightly
やや
どちらとも
2
3
Ordinary
clean いえない
きれい

Slightly
やや
4
dirty
きたない

5
きたない
Dirty

Water clearness
impression _ Evaluated by transparency
水の汚れの印象_透明感で評価

Acceptable range for citizens：Over 70cm transparency

35

Change in Transparency

Upstream Section

The 1st～6th stage： with TRWKRNo rain on the day and the previous day
The 7th～16th stage： No TRWKRNo rain on the day and the previous day
Utilization of reclaimed wastewater at Moriyama
Water Treatment Center was stopped in the 15thstage because of the construction work for the
improvement(April to October, 2014).

Average (from Sakae Bridge to Sanege Bridge)
With TRWKR

Introduction of advanced water treatment at the Meijo Water Treatment Center
In-service of Horikawa Ugan Rain-water Reservoir for pollution control
70cm is citizen’s acceptable value

Utilization of reclaimed wastewater at Moriyama Water Treatment Center
Utilization of groundwater

Over 70cm in the upstreamof Horikawa River after the 12th stage

Numberof data

3

41

13

2

8

3

5

8

5

9

9

7

8

7

7

１

Note） Not enough data

■ How did the transparency change in the upstream section (Sakae Bridge～
Sanage Bridge) ?
→There are not enough data, but transparency after the 12th stage have been over 70cm
( citizen’s acceptable value ).

36

Middle andDownstream Area

The 1st～6th stage： with TRWKRNo rain on the day and the previous day
The 7th～16th stage： No TRWKRNo rain on the day and the previous day

Change in Transparency

Utilization of reclaimed wastewater at Moriyama
Water Treatment Center was stopped in the 15thstage because of the construction work for
improvement (April to October,2014).

Average (from Sanage Bridge to Oseko Bridge）
With TRWKR

Introduction of advanced water treatment at the Meijo Water Treatment Center
In-service of Horikawa Ugan Rain-water Reservoir for pollution control

Improved with TRWKR

Utilization of reclaimed wastewater at Moriyama Water Treatment Center
Utilization of groundwater

Worsened
without TRWKR

Numberof data

55

155

129

36

95

61

77

64

73

Keeping or
improved a little

108

107

84

90

81

79

54

■ How did the transparency change in the downstream section (Sanage Bridge～Oseko
bridge)? → We monitored improving trend with TRWKR and worsening trend in the 7th stage without TRWKR.
However, we monitored slightly improving trend again after the 11th stage. It is considered that these trends are
made by the effect of the new water quality improvement measures. Transparency from autumn to early winter isover 70cm which is citizen’s acceptable value. On the other hand, that from spring to early summer is under 70cm.

37The 1st～6th stage： with TRWKRNo rain on the day and the previous
The 7th～16th stage： No TRWKRNo rain on the day and the previous

Change in Transparency
AverageNote）Area from Minatoshin Bridge to Oseko Bridge
is omitted because of not enough data

Utilization of reclaimed wastewater atMoriyama Water Treatment Center was
stopped in the 15th stage because of the
improvement work (April to October,2014).

Utilization of reclaimed wastewater at Moriyama Water Treatment Center
In-service of Horikawa Ugan Rain-water Reservoir for pollution control

With TRWKR

SectionIntroduction of advanced water treatment at the Meijo Water Treatment Center
Utilization of groundwater(cm)

Sakae Bridge to Sanage Bridge（not enough data）

New water quality improvement measures→improving a little or keeping trend

Sanage Bridge to Johoku Bridge

Johoku Bridge to Asahi Bridge

With TRWKRNo TRWKR→Declining

Asahi Bridge to Matsushige Bridge

Matsushige Bridge to Oseko Bridge

第1st. 第2st. 第3st. 第4st. 第5st. 第6st. 第7st. 第8st. 第9st. 第10st. 第11st. 第12st.第13st. 第14st. 第15st. 第16st.
cm

cm

Transparency is improved a little or kept between Sanage Bridge and Asahi bridge.
We think that is implement of new water quality improvement measures after stopping TRWKR.

３８Change in Transparency

The 1st,3rd, 5th stage： with TRWKRNo rain on the day and the previous day
The 7th, 9th, 11th, 13th, 15th stage： No TRWKRNo rain on the day and the previous day

Average (from spring to early summer)
Sanage城北橋～猿投橋
Bridge to Johoku Bridge
80
60

71

Improved
68

58

58

64

66

63

65

40
20
0
H19.4.22～
6.30

H20.4.1～
6.30

H21.4.1～
6.30

第第1st.
1ｓｔ.

第3st.
第3ｓｔ.

第5st.
第7st.
第9st.
第11st.
第13st.
第15st.
第7ｓｔ.
第5ｓｔ.
第9ｓｔ.
第11ｓｔ.
第13ｓｔ.
第15ｓｔ.

Number 13
of data32

26

H22.4.1～
6.30

19

H23.4.1～
6.30

20

H24.4.1～
6.30

H25.4.1～
6.30

26

H26.4.1～
6.30

16

16

Improved

60

53

52
43

51

54

50

56

40
20
0
H19.4.22～
6.30

H20.4.1～
6.30

H21.4.1～
6.30

H22.4.1～
6.30

H23.4.1～
6.30

H24.4.1～
6.30

H25.4.1～
6.30

H26.4.1～
6.30

第1ｓｔ. 第3ｓｔ. 第5ｓｔ. 第7ｓｔ. 第9ｓｔ. 第11ｓｔ. 第13ｓｔ. 第15ｓｔ.
5
9
11
6
9
Number14
7
9
of data
第1st.

第3st.

第5st.

第7st.

第9st.

第11st.

52

60

57

60

20
0
H19.4.22～
6.30

第第1st.
1ｓｔ.
Number 22of data

第13st.

第15st.

透視度(cm)Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

透視度(cm)Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

59

65

H20.4.1～
6.30

H21.4.1～
6.30

H22.4.1～
6.30

H23.4.1～
6.30

H24.4.1～
6.30

H25.4.1～
6.30

H26.4.1～
6.30

第3st.
第5st.
第7st.
第9st.
第11st.
第13st.
第15st.
第7st.
第3st.
第5st.
第9st.
第11sｔ.
第13ｓｔ.
第15ｓｔ.

56

29

22

20

41

33

27

100

Improved

80
60

60

Matsushige
Bridge to Oseko Bridge
大瀬子橋～松重橋

Note） Not enough data
61

61

40

JohokuBridge to Asahi Bridge
朝日橋～城北橋
100

Asahi Bridge
松重橋～朝日橋
to Matsushige Bridge80

透視度(cm)Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

透視度(cm)Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

100

Improved form Sanage Bridge
to Matsushige
Bridge
100

80
60

59

56

54

56

H21.4.1～
6.30

H22.4.1～
6.30

57

58

56

H25.4.1～
6.30

H26.4.1～
6.30

48

40
20
0
H19.4.22～
6.30

H20.4.1～
6.30

第7ｓ
第1st.
第3st.
第5st.
第7st.
第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
ｔ.

Number 11
of data32

29

Transparency from Sanage Bridge to Matsushige Bridge in the 15th stage got better than that in the 7thstage. Transparency from spring to early summer is less than 70cm which is citizen’s acceptable
value

30

H23.4.1～
6.30

H24.4.1～
6.30

第9st.
第11st.
第13st.
第15st.
第9ｓｔ.
第15ｓｔ.
第11ｓｔ.
第13ｓｔ.

24

26

34

31

３９

Change in Transparency

The 1st,3rd, 5th stage： with TRWKRNo rain on the day and the previous day
The 8th,10th, 12th, 14th, 16th stage： No TRWKRNo rain on the day and the previous day

Average (from autumn to early winter)
Sanage Bridge to Johoku Bridge

Improved form Sanage Bridge
To Oseko Bridge

Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

第2ｓｔ.

Number 35
of data

第4ｓｔ.
8

第6ｓｔ. 第8ｓｔ. 第10ｓｔ.第12ｓｔ. 第14ｓｔ.第16ｓｔ.
17

16

23

18

17

12

Numberof data

第２s
ｔ.
74

16

3

5

12

11

16

22

第2ｓｔ. 第4ｓｔ. 第6ｓｔ. 第8ｓｔ.

第4ｓｔ. 第6ｓｔ. 第8ｓｔ. 第10ｓｔ.第12ｓｔ.第14ｓｔ.第16ｓｔ.
1

18

第８st. 第10st. 第12sｔ.第14ｓｔ. 第16ｓｔ.
40

30

24

11

6

21

Improved

Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

Improved

Note） Not enough data

Numberof data

第４st. 第６st.

Matsushige Bridge to Oseko Bridge

Johoku Bridge to Asahi Bridge

第2ｓｔ.

Improved

Ｔｒａｎｓｐａｒｅｎｃｙ（ｃｍ）

Improved

Asahi Bridge to Matsushige Bridge

Numberof data30

925Transparency from Oseko Bridge to Matsushige Bridge in the 16th stage got better than that in the 8thstage. Transparency from autumn to early winter is less than 70cm which is citizen’s acceptable value.

21

第10ｓｔ. 第12ｓｔ.第14ｓｔ. 第16ｓｔ.
33

25

29

15

４０

６.４. ＣＯＤ
Chemical Oxygen Demand. It means degree of water pollution by organic
substance in the sea, lakes and marshes mainly. It is volume of oxygen which
react on organic substance in water.

COD pack test

How to test
Reagent
is in atube.
Pick here andpull out.
5 minutes

1.

Pull plug out.

2. Put air out.

3. Absorb water fromintake hole.

4. After 5 minutes compare
the color with check sheet.

41

1st – 6th stage : With TRWKRNo rain on the day and the previous day
7th – 15th stage : No TRWKRNo rain on the day and the previous day

Change of COD

Upstream section（between Sakae Bridge and Sanage Bridge, average）

With TRWKR

Introduction of advanced water treatment at Meijo Water Treatment CenterIn service of Horikawa Ugan Rainwater Reservoir for pollution control

20

Utilization of reclaimed wastewater from Moriyama Water Treatment Center
18

Utilization of groundwater

16
16

15
14

14
14

13

COD(mg/L)

12

13
11

11

10
10

9

9

9

9
8

8

8

7

6
4

Upstream section
After 8th stage
Over １０mg/L is more frequently2

Sep.11th～Dec.17th
2010

Apr.1st～Jun.30th2011

7th st.
5

8th st.
8

9th st. 10th st. 11th st. 12th st. 13th st. 14th st. 15th st. 16th st.
9
9
7
1
5
7
8
7

■ How did COD change in the upstream section (between Sakae Bridge and Sanage Bridge)→ COD is over 10mg/L more frequently after 8th stage.

Sep.29th～Dec.16th
2014

Apr.1st～Jun.30th2010

6th st.
6

Apr.1st～Jun.30th
2014

Sep.27th～Dec.16th
2009

5th st.
9

Sec.29th～Dec.17th
2013

Apr.1st～Jun.30th2009

4th st.
6

Apr.1st～Jun.30th
2013

Sep.28th～Dec.16th
2008

3rd st.
13

Sep.22nd～Dec.16th
2012

Apr.1st～Jun.30th2008

2nd st.

Apr.1st～Jun.30th
2012

Sep.8th～Dec.16th
2007

1st st.

Number of5
18
surveyNot enough data

Sep.11th～Dec.16th
2011

Apr.22nd～Jun.30th
2007

0

42

1st – 6th stage : With TRWKRNo rain on the day and the previous day
7th – 15th stage : No TRWKRNo rain on the day and the previous day

Middle and downstream section
Change of COD（between Sanage Bridge and Oseko Bridge, average)
With TRWKR

Introduction of advanced water treatment at Meijo Water Treatment CenterIn service of Horikawa Ugan Rainwater Reservoir for pollution control

20

Utilization of reclaimed wastewater from Moriyama Water Treatment Center

18
16

14
14

improved or kept
with TRWKR

slightly worsened
after the stop of TRWKR

Utilization of groundwatera little fluctuation or kept going up of blue tide or red tide
Rising of sludge
13
after the stop of TRWKR

12
COD(mg/L)

12

11

11

11

11

11
10

10

9

12*

11
10 *

below
10mg/L

10

9

9

8
6
4
2

Sep.27th～Dec.16th
2009

Apr.1st～Jun.30th
2010

Sep.11th～Dec.17th
2010

Apr.1st～Jun.30th
2011

Sep.11th～Dec.16th
2011

5th st.
101

6th st.
87

7th st.
84

8th st.
63

9th st.
75

10th st. 11th st. 12th st. 13th st. 14th st. 15th st. 16th st.
109
112
84
61
85
92
82

■How did COD change in the middle and downstream section (between Sanage Bridge and Oseko Bridge)?
→It seems that COD was improved and kept during TRWKR, slightly worsened after the stop of TRWKR in the 8th stage, andwas fluctuated or kept around 10mg/L. In the 16th stage, it was below 10mg/L for the first time after the stop of TRWKR.
In the 12th and 13th stage, going up of blue tide or red tide and rising of sludge was reported, but the effect of thosedidn’t appear clearly because it supposed that we observed fresh water of a surface.

Apr.1st～Jun.30th
2014

Apr.1st～Jun.30th2009

4th st.
76

Sec.29th～Dec.17th
2013

Sep.28th～Dec.16th
2008

3rd st.
152

Apr.1st～Jun.30th2013

Apr.1st～Jun.30th2008

2nd st.
182

Sep.22nd～Dec.16th
2012

Sep.8th～Dec.16th
2007

1st st.
115

Apr.1st～Jun.30th
2012

Apr.22nd～Jun.30th
2007
Numberof survey

Sep.29th～Dec.16th
2014

0

43

1st – 6th stage : With TRWKRNo rain on the day and the previous day
7th – 15th stage : No TRWKRNo rain on the day and the previous day

Change of COD（average in some sections）
between Minatoshin Bridge and Oseko Bridge is exceptedWith TRWKR
Introduction of advanced water treatment at Meijo Water Treatment CenterIn service of Horikawa Ugan Rainwater Reservoir for pollution control
Utilization of reclaimed wastewater from Moriyama Water Treatment Center
Utilization of groundwatersection
Sakae Bridge–
Sanage Bridge

mg/L
8

8

(not enough data)

12

10

10

new water quality improvement measure after the stop10of TRWKR
14
14
12→ slightly improved

Sanage Bridge –Johoku Bridge

10

10

12

12
14

Johoku Bridge –Asahi Bridge

12

12

3rd

a little fluctuation or kept
after the stop of TRWKR

12
10

2nd

14

10

16

12

12

Matsushige Bridge –Oseko Bridge
1st

12

12

14

Asahi Bridge –Matsushige Bridge

1210slightly worsened
after the stop of TRWKR

with TRWKR(not enough data)

12

10

4th

10

5th

6th

10

10
10

8

8

8

7th

8th

9th

10th

11th

12th

13th

14th

15th

16th

Stage
mg/L

mg/L

We think that the COD readings have been better between Sanage Bridge and Asahi Bridge mainly
because of effect by new water quality improvement measure after the stop of TRWKR.

44

1st,3rd,5th stage : With TRWKRNo rain on the day and the previous day
7th,9th,11th,13th,15th stage : No TRWKRNo rain on the day and the previous day

Change of COD spring – early summer
It was improved between
Sanage Bridge – Sanage
Bridge and Johoku18
Bridge.
Johoku Bridge
15
16
20

18
16

14

13

12

9

10

11

11

12

improved
9

8

4

2

2
0

1st
st. 1st st.

Number 43
of survey

45

Apr.1st～Jun.30th2011

Apr.1st～Jun.30th2012

Apr.1st～Jun.30th2013

Apr.1st～Jun.30th
2014

31

24

20

27

16

16

15

14

11

12

12
9

10

10

11

8

1st
1st st.

12
10

2
0

1st
st.1st st.
Numberof survey

15

Apr.1st～Jun.30th2011

Apr.1st～Jun.30th2012

Apr.1st～Jun.30th2013

Apr.1st～Jun.30th
2014

7th
3rd
9th
3rd st.st. 5th
5th st.st.
7th st.st.
9th st.st. 11th
11th st. st. 13th
13th st. st. 15th
15th st. st.
16

12

6

9

14

7

5

12

13

29

Apr.1st～Jun.30th2010

Apr.1st～Jun.30th2011

Apr.1st～Jun.30th2012

Apr.1st～Jun.30th
2013

14

22

24

42

35

8

Apr.22nd～
Jun.30th2007
1st st.
1stst.

Number 19
of survey

Apr.1st～Jun.30th2008

3rd
3rd st.
st.
31

9

Apr.1st～Jun.30th2009

8

Apr.1st～Jun.30th2010

33

worsened
11

10

Apr.1st～Jun.30th2014

7th st.
9th st.
11th st.st. 13th
13th st.st. 15th
15th st. st.
7th
st. 9thst. 11th

Matsushige Bridge –Oseko Bridge

82
Apr.1st～Jun.30th
2010

13

14

4

Apr.1st～Jun.30th
2009

60

16

4

Apr.1st～Jun.30th2008

Apr.1st～Jun.30th2009

3rd st.
st.
5th st.
st.
3rd
5th

18

6

Apr.22nd～
Jun.30th2007

Apr.1st～Jun.30th
2008

20

6

0

Apr.22nd～
Jun.30th2007

Number st.38
of survey

worsened
Johoku Bridge –not enough data
Asahi Bridge
15

18

12

Apr.1st～Jun.30th2010

7th
st. 9th
3rd3rdst.
5th5thst.
st. 11thst.
st.
7th st.
9th st.
11th st.st. 13th
13th st.st. 15th
15th st. st.

20
16

Apr.1st～Jun.30th
2009

12

8

4

Apr.1st～Jun.30th2008

13

worsened

10
6Apr.22nd～
Jun.30th2007

14

Asahi Bridge –Matsushige Bridge

12

6

0

COD(mg/L)

10

14

COD(mg/L)

COD(mg/L)

14

COD(mg/L)

20

9

9

Apr.1st～Jun.30th2011

Apr.1st～Jun.30th2012

Apr.1st～Jun.30th2013

12

Apr.1st～Jun.30th2014

5th st.st. 7th
7th st.st.
9th st.st. 11th
11th st.st. 13th
13th st. st. 15th
15th st. st.
5th
9th

29

COD in the 15th stage was improved between Sanage Bridge and Johoku Bridge but worsened between
Johoku Bridge and Oseko Bridge in comparison with in the 7th stage just after the stop of TRWKR.

30

24

26

34

30

45

2nd,4th,6th stage : With TRWKRNo rain on the day and the previous day
8th,10th,12th,14th,156h stage : No TRWKRNo rain on the day and the previous day

Change of COD autumn – early winter

18

13

14
12

9

9

11
9

improved
8

8

12

4

2

2
0

Sec.29th～
Dec.17th2013

Sep.29th～
Dec.16th2014

Sep.8th～Dec.16th
2007

Sep.28th～
Dec.16th
2008

Sep.27th～
Dec.16th2009

Sep.11th～
Dec.17th2010

Sep.11th～
Dec.16th2011

4th st.
4thst.
20

6th st.
6thst.
24

8th st.
8th
st.
16

10th st.st. 12th
12th st.st. 14th
14th st.st. 16th
16th st.st.
10th
18
17
12
23

2nd st.
st.
Number 2ndof survey 70

4th st.
4thst.
30

6th st.
6thst.
21

8th st.
8th
st.
25

10th st.
12th st.st. 14th
14th st.st. 16th
16th st.st.
10th
st. 12th
31
25
29
43

12
10

Sep.22nd～
Dec.16th2012

Sec.29th～
Dec.17th
2013

20

10

9

16

improved

12
10

10

6

14
12
10

4
2

4th
st.
4th st.
6

6thst.
6th st.
9

Sep.11th～
Dec.17th
2010

8th
st.
8th st.
5

Sep.11th～
Dec.16th
2011

Sep.22nd～
Dec.16th2012

Sec.29th～
Dec.17th2013

Sep.29th～
Dec.16th
2014

10th
st. 12thst. 14thst. 16th
10th st.
12th st.
14th st.
16th st.st.
11
11
6
12

7

6

2
Sep.27th～
Dec.16th
2009

10

8

4

Sep.28th～
Dec.16th
2008

Matsushige Bridge –Oseko Bridge

18

8

Number 2ndst.
2nd st.
of survey 21

10

Sep.29th～
Dec.16th2014

13

Sep.8th～Dec.16th
2007

Sep.22nd～
Dec.16th2012

10

Sep.11th～
Dec.16th
2011

16

0

11

Sep.11th～
Dec.17th2010

Johoku Bridge –not enough data
Asahi Bridge

1011

Sep.27th～
Dec.16th
2009

18

12

11

Sep.28th～
Dec.16th
2008

20

14

11

8

4

2nd st.st.
Number 2ndof survey 54

11

10
6

Sep.8th～Dec.16th
2007

improved

13

14

6

0

COD(mg/L)

12

9Asahi Bridge –Matsushige Bridge

It was improved between
18
Sanage Bridge and Johoku
Bridge.
16

COD(mg/L)

COD(mg/L)

16

10

20

Sanage Bridge –Johoku Bridge

COD(mg/L)

20

0

8
6

9
7

9
7

Sep.8th～Dec.16th
2007

Sep.28th～
Dec.16th
2008

Sep.27th～
Dec.16th2009

Sep.11th～
Dec.17th2010

Sep.11th～
Dec.16th
2011

Number 2nd
2nd st.st.
of survey 37

4th st.
4thst.
20

6th st.
6thst.
33

8th st.
8th
st.
17

10th st.st. 12th
12th st.st. 14th
14th st.
16th st.st.
10th
st. 16th
25
29
14
34

COD in the 16th stage was improved between Sanage Bridge and Matsushige Bridge in comparison with in the 8th stage
just after the stop of TRWKR. It was improved to 8mg/L especially between Sanage Bridge and Johoku Bridge.

Sep.22nd～
Dec.16th2012

Sec.29th～
Dec.17th2013

Sep.29th～
Dec.16th2014

46

1st-6th stage ： With TRWKRNo rain on the day and the previous day
7th -16th stage ： No TRWKRNo rain on the day and the previous day

６.５. Bubbles

Upper stream

Occurrence of bubbles from river bottom
泡Ratioの 発 生of状況_泡 が 川occurrence(%)
底 か ら 浮 い て く る 割 合 ( %)bubbleAverage number(Sakae
bridge-Sanagebashi bridge)
栄橋～猿投橋間
With TRWKR

100Introduction of Advanced treatment at Meijo Wastewater Treatment CenterIn- service of Horikawa Ugan Rain-water Reservoir for Pollution Control
Utilization of reclaimed wastewater from Moriyama Water Treatment Center

80

Utilization of groundwater
60
50
40

No reports of bubble occurrence inupper stream area after 6th stage

33
25

20

13
3

0

H24.4.1～ 6.30

H24.9.22～ 12.16

H25.4.1～ 6.30

H25.9.29～ 12.17

H26.4.1～ 6.30

H26.9.29～ 12.16

0

H23.9.11～ 12.16

0

H23.4.1～ 6.30

0H22.9.11～ 12.17

0

H22.4.1～ 6.30

0H21.9.27～ 12.16

0

H21.4.1～ 6.30

0H20.9.28～ 12.16

0

H20.4.1～ 6.30

0H19.9.8～ 12.16

Data

0

H19.4.22～ 6.30

0

第1st.

第2st.

第3st.

第4st.

第5st.

第6st.

第7st.

第8st.

第9st.

第10st.

第11st.

第12st.

第13st.

第14st.

第15st.

第16st.

24

38

15

2

8

3

5

8

5

9

9

8

8

7

7

1

*Not enough data

■ How the state of bubbles changed in upper stream area(Sakae bridge-Sanage bridge)？
→Although data isn’t enough, there are no reports of bubble occurrence after 6th stage.

47

1st-6th stage ： With TRWKRNo rain on the day and the previous day
7th -16th stage ： No TRWKRNo rain on the day and the previous day

Midstream/Downstream

Occurrence of bubbles from river bottom
猿投橋～大瀬子橋間
Average number(Sanage
bridge-Oseko bridge)
With TRWKR

Introduction of Advanced treatment at Meijo Wastewater Treatment CenterIn- service of Horikawa Ugan Rain-water Reservoir for Pollution Control

80

Utilization of reclaimed wastewater from Moriyama Water Treatment Center
Utilization of groundwater

60

With TRWKR
Improving trend

40
24

Slightly worsened
21

20

20

Without TRWKR
Spring-Early Summer→In gradual Improving trend
Autumn-Early Winter→Remain under 10%

Bottom sludge was in bad
condition due to hightemperature→Worsened
25

21

19

15
9

8

7

20

17

7

2

6

2

H20.4.1～ 6.30

H20.9.28～ 12.16

H21.4.1～ 6.30

H21.9.27～ 12.16

H22.4.1～ 6.30

H22.9.11～ 12.17

H23.4.1～ 6.30

H23.9.11～ 12.16

H24.4.1～ 6.30

H24.9.22～ 12.16

H25.4.1～ 6.30

H25.9.29～ 12.17

H26.4.1～ 6.30

H26.9.29～ 12.16

Data

H19.9.8～ 12.16

0
H19.4.22～ 6.30

泡 の Ratio
発 生 状 of
況 _泡が 川 底occurrence(%)
か ら 浮 い て く る 割 合 ( %)bubble

100

第1st.

第2st.

第3st.

第4st.

第5st.

第6st.

第7st.

第8st.

第9st.

第10st.

第11st.

第12st.

第13st.

第14st.

第15st.

第16st.

105

206

167

47

97

59

82

63

73

108

100

94

87

75

72

59

■ How bubbles changed in down and midstream area(Sanage bridge-Oseko bridge)?
→With TRWKR, bubbles from the bottom have been in improving trend. But after stopping TRWKR it has worsened between 7th and9th stage. From Spring to early Summer it is in improving trend. Also from Autum to early Winter it has worsened at 12th stage but
the rest is remaining within 10%. Comparing to 7th and 8th stage without TRWKR and 15th and 16th stage, bubbles have slightly
improved. We speculate the reason bubbles have worsened at 12th stage is caused by bad condition of the bottom sludge, due totemporal high temperature.

48

1st-6th stage ： With TRWKRNo rain on the day and the previous day
7th -16th stage ： No TRWKRNo rain on the day and the previous day

100
80
60
40
20

36

32
21

31 improved

20

19

13

11

0
H19.4.22～6.30

Ratio of bubble occurrence(%)
泡の発生状況_泡が川底から浮いてくる割合(%)

Data

第1ｓ
第1st.
ｔ.
33

H20.4.1～6.30

H21.4.1～6.30

H22.4.1～6.30

H23.4.1～6.30

H24.4.1～6.30

H25.4.1～6.30

H26.4.1
～6.30

第3st.
第5st.
第7st.
第9st.
第11st.
第13st.
第15st.
第7ｓｔ.
第11ｓｔ.
第13ｓｔ.
第3ｓｔ.
第5ｓｔ.
第9ｓｔ.
第15ｓｔ.

27

42

25

20

22

16

16

城北橋～朝日橋
JohokuBridge-Asahi Bridge

100*Not enough data
80
60

Worsened
40
20

21
8

0
H19.4.22
～6.30

Data

第1ｓ
第1st.
ｔ.
12

0
H20.4.1～6.30

8
H21.4.1
～6.30

20

10
0
H22.4.1～6.30

0H23.4.1～6.30

H24.4.1～6.30

H25.4.1～6.30

H26.4.1～6.30

朝日橋～松重橋 Bridge
Asahi Bridge-Matsushige

泡の発生状況_泡が川底から浮いてくる割合(%)
Ratio of bubble occurrence(%)

猿投橋～城北橋
SanageBridge-Johoku Bridge

100
80
60

12

5

10

14

7

5

58

56

40

improved
40

38

31
18

20
0
H19.4.22
～6.30

Data

第1ｓ
第1st.
ｔ.
45

H20.4.1
～6.30

第3ｓ
第3st.
ｔ.
81

H21.4.1～6.30

H22.4.1～6.30

H23.4.1～6.30

H24.4.1～6.30

H25.4.1～6.30

H26.4.1
～6.30

第5st.
第7st.
第9st.
第11st.
第13st.
第15st.
第7ｓｔ.
第5ｓｔ.
第9ｓｔ.
第11ｓｔ.
第13ｓｔ.
第15ｓｔ.

31

24

19

39

35

32

松重橋～大瀬子橋
Matsushige
Bridge-Oseko Bridge
100
80
60
40
20

improved
7

14
3

0

第3st.
第5st.
第7st.
第9st.
第11st.
第13st.
第15st.
第7ｓｔ.
第3ｓｔ.
第5ｓｔ.
第9ｓｔ.
第11ｓｔ.
第13ｓｔ.
第15ｓｔ.

145842

泡の発生状況_泡が川底から浮いてくる割合(%)
Ratio of bubble occurrence(%)

Ratio of bubble occurrence(%)
泡の発生状況_泡が川底から浮いてくる割合(%)

Occurrence of bubbles from bottom(Spring-Early Summer)

Data

H19.4.22
～6.30

第1ｓ
第1st.
ｔ.
15

H20.4.1
～6.30

13

8

7

5

H24.4.1～6.30

H25.4.1～6.30

H26.4.1～6.30

0H21.4.1～6.30

H22.4.1～6.30

H23.4.1
～6.30

第7ｓｔ.
第3ｓｔ.
第5ｓｔ.
第9ｓｔ.
第15ｓｔ.
第3st.
第5st.
第7st.
第9st.
第11st.
第13st.
第15st.
第11ｓｔ.
第13ｓｔ.
30

27

28

24

From spring to early summer bubbles have improved between Sanage and Johoku bridge, and between Asahi andOseko bridge compared with 15th and 7th stage without TRWKR.

25

29

19

49

Occurrence of bubbles from bottom(Autumn-Early Winter)

2nd,4th,6th stage ： With TRWKRNo rain on the day and the previous day
8th,10th,12th,14th,16th stage ： No TRWKRNo rain on the day and the previous day

朝日橋～松重橋 Bridge
Asahi Bridge-Matsushige
100

100

Bottom sludge was in bad
condition due to hightemperature→Worsened8060

Worsened
40

25
20

6

0
H19.9.8～12.166

0
H20.9.28～12.16

H21.9.27～12.1613
H22.9.11～12.17

13
H23.9.11～12.1617
6

H24.9.22～12.16

H25.9.29～12.17

H26.9.29～12.16

第2st.
第4st.
第6st.
第8st.
第10st.
第12st.
第14st.
第16st.
第2ｓｔ.
第4ｓｔ.
第8ｓｔ.
第16ｓｔ.
第6ｓｔ.
第10ｓｔ.
第12ｓｔ.
第14ｓｔ.

Data

泡の発生状況_泡が川底から浮いてくる割合(%)
Ratio of bubble occurrence(%)

Ratio of bubble occurrence(%)
泡の発生状況_泡が川底から浮いてくる割合(%)

猿投橋～城北橋
SanageBridge-Johoku Bridge

47

17

9

16

23

20

12

17

80

Bottom sludge was in bad
condition due to hightemperature→Worsened

60
40

23
20

13

0
H19.9.8～12.16

40

17

20

5

0

0

Data

H19.9.8～12.16

H20.9.28～12.160
H21.9.27～12.160
H22.9.11～12.170
H23.9.11～12.160
H24.9.22～12.16

H25.9.29～12.170
H26.9.29～12.16

第2ｓｔ.
第4ｓｔ.
第8ｓｔ.
第2st.
第4st.
第6st.
第8st.
第10st.
第12st.
第14st.
第16st.
第16ｓｔ.
第6ｓｔ.
第10ｓｔ.
第12ｓｔ.
第14ｓｔ.
21

2

3

5

12

12

H22.9.11～12.17

H23.9.11～12.16

H24.9.22～12.16

H25.9.29～12.17

7
H26.9.29～12.16

第2st.
第4st.
第6st.
第8st.
第10st.
第12st.
第14st.
第16st.
第2ｓｔ.
第4ｓｔ.
第8ｓｔ.
第16ｓｔ.
第6ｓｔ.
第10ｓｔ.
第12ｓｔ.
第14ｓｔ.

Data

10

6

Ratio of bubble occurrence(%)
泡の発生状況_泡が川底から浮いてくる割合(%)

泡の発生状況_泡が川底から浮いてくる割合(%)
Ratio of bubble occurrence(%)

Bottom sludge was in bad
condition due to hightemperature→Worsened60

H21.9.27～12.16

0

104

27

15

23

42

40

24

29

松重橋～大瀬子橋
Matsushige
Bridge-Oseko Bridge*Not enough data80

H20.9.28～12.16

improved

120

城北橋～朝日橋
JohokuBridge-Asahi Bridge
100

35

30

100
80
60
40
20

3
0

Data

H19.9.8～12.16000H20.9.28～12.16

H21.9.27～12.16

H22.9.11～12.17

第2st.
第4st.
第2ｓｔ.
第4ｓｔ.

34

9

3
H23.9.11～12.16000H24.9.22～12.16

H25.9.29～12.17

H26.9.29～12.16第6st.
第8st.
第10st.
第12st.
第14st.
第16st.
第8ｓｔ.
第16ｓｔ.
第6ｓｔ.
第10ｓｔ.
第12ｓｔ.
第14ｓｔ.

24

19

31

From autumn to early winter occurrence of bubbles have improved between Asahi and Matsushige
bridge compared with 16th and 8th stage without TRWKR.

22

24

12

50

６.６. Ｓｍｅｌｌ

1st-6th stage ： With TRWKRNo rain on the day and the previous day
7th-16th stage ： No TRWKRNo rain on the day and the previous day

Occurrence of Smell

Upstream section(Sakae Bridge – Sanage Bridge)（Av. From Sakae Bridge to Sanage Bridge）
Introduction of Advanced treatment at Meijo Wastewater Treatment Center
In-service of Horikawa Ugan Rain-water Reservoir for Pollution Control

100

Utilization of Reclaimed Wastewater
80

Utilization of groundwater

60

There is no reports of “terrible smell –smell”,
thafter 9 stage, in Upstream section.

50
40

20

13
0

0

0

0

0

0

0

0

H24.4.1～6.30

H24.9.22～12.16

H25.4.1～6.30

H25.9.29～12.17

H26.4.1～6.30

H26.9.29～12.16

0

H23.9.11～12.16

0

H23.4.1～6.30

0H22.9.11～12.17

H20.9.28～12.16

H20.4.1～6.30

H19.9.8～12.16

0

H22.4.1～6.30

7

H21.9.27～12.16

3

H21.4.1～6.30

9H19.4.22～6.30

Occurrence ofにおいの発生状況_ひどく臭う～臭う割合(%)
smell the ration of Terrible smell and Bad Smell, Smell(%)

With TRWKR

第1ｓｔ. 第2ｓｔ. 第3ｓｔ. 第4ｓｔ. 第5ｓｔ. 第6ｓｔ. 第7ｓｔ. 第8ｓｔ. 第9ｓｔ. 第10ｓｔ. 第11ｓｔ. 第12ｓｔ. 第13ｓｔ. 第14ｓｔ. 第15ｓｔ. 第16ｓｔ.
Ｓａｍｐｌｅ

23

40

15

2

8

3

5

8

5

9

9

8

8

7

7

1

*Few data■ Change of smell in upstream section→ There is no reports of “terrible smell – smell”, after 9th stage, although few data.

51

Occurrence of Smell

1st-6th stage ： With TRWKRNo rain on the day and the previous day
7th-16th stage ： No TRWKRNo rain on the day and the previous day

Middle stream, Downstream section (Sanage Bridge – Oseko Bridge)
With TRWKR

Introduction of Advanced treatment at Meijo Wastewater Treatment Center100

In-service of Horikawa Ugan Rain-water Reservoir for Pollution Control
Utilization of Reclaimed Wastewater

80

Utilization of groundwater
60

With TRWKR
Improved/kept

40

Because of the high temperature period, the state of
the sludge, at bottom of the river, was not good.
So, blue tide and red tide was coming upstream, andsludge was rised in a surface of the river. →Worsened

45

33

31
23
20

25
19

13

28

Worsened 18

27

Without TRWKR
Improved/kept
19

14

14

12

7

3

第7ｓｔ.

第8ｓｔ.

第9ｓｔ.

106

210

170

50

109

62

84

67

75

H26.9.29～12.16

H23.4.1～6.30

第6ｓｔ.

H26.4.1～6.30

H22.9.11～12.17

第5ｓｔ.

H25.9.29～12.17

H22.4.1～6.30

第4ｓｔ.

H25.4.1～6.30

H21.9.27～12.16

第3ｓｔ.

H24.9.22～12.16

H21.4.1～6.30

第2ｓｔ.

H24.4.1～6.30

H20.9.28～12.16

第1ｓｔ.

H23.9.11～12.16

H20.4.1～6.30

ＳａｍｐｌｅH19.9.8～12.16

0

H19.4.22～6.30

Occurrence ofsmell the ration of Terrible smell and Bad Smell, Smell(%)においの発生状況_ひどく臭う～臭う割合(%)（Av. From Sanage Bridge to Oseko Bridge）

第10ｓｔ. 第11ｓｔ. 第12ｓｔ. 第13ｓｔ. 第14ｓｔ. 第15ｓｔ. 第16ｓｔ.
113

108

98

93

82

87

62

■Change of smell in middle stream and downstream section→At 7th and 8th stage, just after the TRWKR, the smell was worsened. After that, At 12th and 13th stage, the smell was
worsened, but in other stages, it was not worsened.
The occurrence of smell, at 15th and 16th stage, reduced to less than half compared at 7th and 8th stage.
At the 12th and 13th stage, the occurrence of smell was increased. The reason is considered as follows. Because of the hightemperature, the state of the sludge, at bottom of the river, was not good. So, blue tide and red tide was coming upstream, andsludge was raised toward a surface of the river.

52

1st,3rd,5th stage ： With TRWKRNo rain on the day and the previous day
7th,9th,11th,13th,15th stage ： No TRWKRNo rain on the day and the previous day

Occurrence of Smell
100
80
60
40

29

27
15

20

10

10

Improved

16
6

0

0
H19.4.22～6.30

H20.4.1～6.30

H21.4.1～6.30

H22.4.1～6.30

H23.4.1～6.30

H24.4.1～6.30

H25.4.1～6.30

H26.4.1～6.30においの発生状況_におう～ひどくにおうの割合（％）

Sanage 猿投橋～城北橋
Bridge～Johoku Bridge

Occurrence of smell the ration of Terrible smell and Bad Smell, Smell(%)においの発生状況_におう～ひどくにおうの割合（％）
Occurrenceof smell the ration of Terrible smell and Bad Smell, Smell(%)

Spring～Early summer

朝日橋～松重橋 Bridge
Asahi Bridge～Matsushige
100
80

Improved
60
40

Sample

42

30

24

20

25

16

16

37

0
H19.4.22～6.30

Improved
33
16

14

20

7
0

0

SampleH19.4.22～6.30

H20.4.1～6.30

H21.4.1～6.30

H22.4.1～6.30

H23.4.1～6.30

H24.4.1～6.30

H25.4.1～6.30

H26.4.1～6.30においの発生状況_におう～ひどくにおうの割合（％）
水の汚れの印象（％）

60
50

20

46

100
100

14

13

5

9

14

H21.4.1～6.30

H22.4.1～6.30

H23.4.1～6.30

H24.4.1
～6.30

81

37

25

22

43

7

5

Because of the high temperature, the state of thesludge, at bottom of the river, was not good.
So, blue tide and red tide was coming upstream, andsludge was raised toward a surface of the river.
→Worsened

80
80
60
60

39
39

40
40
20
20
0
0

H25.4.1～6.30

H26.4.1
～6.30

35

34

46
46

54
54

38
38

31
31

7
7

Improved
4
4

15
15

H19.4.22～6.30

H20.4.1～6.30

H21.4.1～6.30

H22.4.1～6.30

H23.4.1～6.30

H24.4.1～6.30

H25.4.1～6.30

H26.4.1～6.30

H19.4.22
第1ｓｔ.
～6.30

H20.4.1
第3ｓｔ.
～6.30

H21.4.1
第5ｓｔ.
～6.30

H22.4.1
第7ｓｔ.
～6.30

H23.4.1
第9ｓｔ.
～6.30

H24.4.1
第11ｓｔ.
～6.30

H25.4.1
第13ｓｔ.
～6.30

H26.4.1
第15ｓｔ.
～6.30

第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
第7ｓｔ.
第9ｓｔ. 第11ｓｔ.
第11ｓｔ. 第13ｓｔ.
第13ｓｔ. 第15ｓｔ.
第15ｓｔ.
第7ｓｔ.
第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
第9ｓｔ.

第1ｓｔ.
第7ｓｔ.
第3ｓｔ.
第5ｓｔ.
第9ｓｔ.
第11ｓｔ.第13ｓｔ.第15ｓｔ.
第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
第7ｓｔ.
第9ｓｔ.
第11ｓｔ.
第13ｓｔ.
第15ｓｔ.
12

H20.4.1
～6.30

第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
第7ｓｔ.
第9ｓｔ.
第11ｓｔ. 第13ｓｔ.第15ｓｔ.
第13ｓｔ.
第15ｓｔ.
第7ｓｔ.
第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
第9ｓｔ.
第11ｓｔ.

SampleOccurrence of smell the ration of Terrible smell and Bad Smell, Smell(%)

Occurrenceにおいの発生状況_におう～ひどくにおうの割合（％）
of smell the ration of Terrible smell and Bad Smell, Smell(%)* Few data

40

39

35

32

松重橋～大瀬子橋
Matsushige
Bridge～Oseko Bridge

80
60

44

19

Johoku 城北橋～朝日橋
Bridge～Asahi Bridge
100

43

20

第7ｓｔ.
第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
第9ｓｔ.
第1ｓｔ.
第3ｓｔ.
第5ｓｔ.
第7ｓｔ.
第9ｓｔ. 第11ｓｔ.
第11ｓｔ. 第13ｓｔ.
第13ｓｔ. 第15ｓｔ.
第15ｓｔ.
33

39

Sample

15

33

29

30

The occurrence of the smell, between Sanage Bridge and Oseko Bridge, from spring to earlysummer, was decreased at 15th stage, compared with 7th stage.

24

26

35

32

53

2nd,4th,6th stage ： With TRWKRNo rain on the day and the previous day
8th,10th,12th,14th,16th stage ： No TRWKRNo rain on the day and the previous day

Occurrence of Smell

10080

Because of the high temperature, the state of the sludge, atbottom of the river, was not good.
So, blue tide and red tide was coming upstream, and sludge
was raised toward a surface of the river. →Worsened

60
40

25

Improved

17

20

2

9

6

6

H21.9.27～12.16

H22.9.11～12.170
H19.9.8～12.16

H20.9.28～12.16

H23.9.11～12.16

H24.9.22～12.1600

H25.9.29～12.17

H26.9.29～12.16

Occurrence of smell the ration of Terrible smell and Bad Smell, Smell(%)

Occurrence of smell the ration of Terrible smell and Bad Smell, Smell(%)においの発生状況_におう～ひどくにおうの割合（％）

Sanage猿投橋～城北橋
Bridge～Johoku Bridgeに おいの 発生状況_に おう～ひどくにおうの割合（％）

Autumn～Early winter

Asahi Bridge～Matsushige
朝日橋～松重橋 Bridge
100

60

11

16

23

20

17

11

23

Johoku城北橋～朝日橋
Bridge～Asahi Bridge

100

Because of the high temperature, the state of thesludge, at bottom of the river, was not good.
So, blue tide and red tide was coming upstream, andsludge was raised toward a surface of the river.
→Worsened

80
60

50
41

40

40
20

* Few data

36 Improved

15
00
H19.9.8～12.16

H20.9.28～12.16

H21.9.27～12.160
H22.9.11～12.17

H23.9.11～12.160
H24.9.22～12.16

H25.9.29～12.17

H26.9.29～12.16

21

2

4

5

12

12

11

6

26
12

4

8

10

H25.9.29～12.17

H26.9.29～12.169

0
H19.9.8～12.16

H20.9.28～12.16

H21.9.27～12.16

H22.9.11～12.17

H23.9.11～12.16

H24.9.22～12.16

第2ｓｔ.
第4ｓｔ.
第8ｓｔ.
第6ｓｔ.
第2ｓｔ.
第4ｓｔ.
第6ｓｔ.
第8ｓｔ. 第10ｓｔ.
第10ｓｔ. 第12ｓｔ.
第12ｓｔ. 第14ｓｔ.
第14ｓｔ. 第16ｓｔ.
第16ｓｔ.
107

28

16

25

43

40

25

29

松重橋～大瀬子橋
Matsushige
Bridge～Oseko Bridge
100
80

Because of the high temperature, the state of the sludge, atbottom of the river, was not good.
So, blue tide and red tide was coming upstream, and sludge wasraised toward a surface of the river. →Worsened

60

38

40
20

29
12

11

15

13

Improved

4

0

0

第2ｓｔ.
第4ｓｔ.
第8ｓｔ.
第16ｓｔ.
第6ｓｔ.
第10ｓｔ.
第12ｓｔ.
第14ｓｔ.
第2ｓｔ.
第4ｓｔ.
第6ｓｔ.
第8ｓｔ.
第10ｓｔ.
第12ｓｔ.
第14ｓｔ.
第16ｓｔ.
Sample19

20

Sampleに おいの発生状況_におう～ひどくにおうのOccurrenceof smellthe ration of Terrible
smell and Bad
Smell,割合（％）
Smell(%)においの発生状況_におう～ひどくにおうの割合（％）

Occurrence of smell the ration of Terrible smell and Bad Smell, Smell(%)

Sample17

Improved

40

第2ｓｔ.
第4ｓｔ.
第8ｓｔ.
第6ｓｔ.
第10ｓｔ.
第12ｓｔ.
第2ｓｔ.
第4ｓｔ.
第6ｓｔ.
第8ｓｔ.
第10ｓｔ.
第12ｓｔ. 第14ｓｔ.
第14ｓｔ. 第16ｓｔ.
第16ｓｔ.
47

Because of the high temperature, the state of the sludge, atbottom of the river, was not good.
So, blue tide and red tide was coming upstream, and sludge
was raised toward a surface of the river. →Worsened80

H19.9.8～12.16

H20.9.28～12.16

H21.9.27～12.16

H22.9.11～12.17

H23.9.11～12.16

H24.9.22～12.16

H25.9.29～12.17

H26.9.29～12.16

第2ｓｔ.
第4ｓｔ.
第8ｓｔ.
第6ｓｔ.
第10ｓｔ.
第2ｓｔ.
第4ｓｔ.
第6ｓｔ.
第8ｓｔ.
第10ｓｔ. 第12ｓｔ.
第12ｓｔ. 第14ｓｔ.
第14ｓｔ. 第16ｓｔ.
第16ｓｔ.
Sample

35

9

25

21

The occurrence of the smell, between Sanage Bridge and Oseko Bridge, from autumn toearly winter, was decreased at 16th stage, compared with 8th stage.

35

26

29

16

54

Kind of smell （each division）・・・spring～early summer
Introduction of Advanced treatment at Meijo Wastewater Treatment CenterWith TRWKR•In-service of Horikawa Ugan Rain-water Reservoir for Pollution Control
Utilization of Reclaimed Wastewater（April～October)）
Utilization of groundwater

1st,3rd,5th stage ： With TRWKRNo rain on the day and the previous day
7th,9th,11th,13th,15th stage ： No TRWKRNo rain on the day and the previous day

With TRWKR

Few data■Change of the smell, fromspring to early summer,
between Sanage bridge to
Minatoshin bridge

Ｎｏ ｄａｔａWith TRWKR

86%

82%

79%

88%

86%
76%

86%

→The amount of ”Ditch” and“Sludge” was about 80%.
Each rate was about 40%.
There is no significant change
in 7th stage and 15th stage.

About 40%

No data

The rate of “Ditch”＋“Sludge” is about 80%

About 40%
* 0% item isn’t displayed.

55

Kind of smell （each division）・・・autumn～early winterIntroduction of Advanced treatment at Meijo Wastewater Treatment CenterWith TRWKR•In-service of Horikawa Ugan Rain-water Reservoir for Pollution Control
Utilization of Reclaimed Wastewater（April～October)）
Utilization of groundwaterWith TRWKR

2nd,4th ,6th stage ： With TRWKRNo rain on the day and the previous day
8th,10th,12th,14th,16th stage ： No TRWKRNo rain on the day and the previous day■Change of the smell, fromautumn to early winter,between Sanage bridge to
Minatoshin bridge

Few data→After TRWKR to 14th stage, theamount of ”Ditch” and “Sludge”
was about 80%.
At 16th stage, it was especiallyreduced the smell of “Sludge”.

95%

With TRWKR
81%

70%

83%

83%

86%

80%

Shinsuzaki bridge 2data
Johoku bridge 1data
56% →report of at neap tide and middle tide

decreased
From the stop of TRWKR to 14th stage, the rate of “Ditch” + “Sludge” was about 80%.
At 16th stage, “Sludge” was decreased.

* 0% item isn’t displayed.

56

The difference in the occurrence of smell
between “bubbles from the bottom” and“no bubbles from the bottom.

Relation between bubbles and smell

All stage, with TRWKR and No TRWKR
Include out of survey period
No rain on the day and the previous day

Asahi bridge ～ Matsushige bridge
Between Asahi bridge – Matsushige bridge
Average of each stage

Sanage bridge ～ Minatoshin bridge

1st - 6th stage ： With TRWKRNo rain on the day and the previous day
7th - 16th stage ： No TRWKRNo rain on the day and the previous day

The total rate of terrible smell,bad smell and smell is 44％.

The ratio of “terrible smell – smell” was 44%, at “bubbles from the bottom”. On
the other hand, that was 19% at “no bubbles from the bottom”.
Smell was often getting worse, when “bubble from the bottom” was occurred. Thistendency was seen clearly between Asahi bridge and Matsushige bridge thanother area.

The total rate of terrible smell,bad smell and smell is 19％.

In past surveys, that had been foundthat bubble was often occurred when
the water level was low.

57

Relation of “Water clearness impression”, “Bubbles from the bottom” and “Smell”
1st - 6th stage ： With TRWKRNo rain on the day and the previous day

7th - 16th stage ： No TRWKRNo rain on the day and the previous day

It was seen clear relation between“Bubbles from the bottom” and“Smell”than other area.

58

６.７. colors①colorless⑥gray⑪dark gray②milkywhite⑦yellowgray⑫pale
yellow gray③yellow⑧pale grayyellow green⑬yellowbrown④yellow
green

⑨gray
yellow green⑭brown⑤green

⑩gray
green

⑮greenbrown

Taken at Nishiki
bridge⑤green⑦yellow gray

⑧pale gray yellow
green⑨gray yellow
green⑩gray green⑪dark gray

There was areport thatfishes were
suffering at “⑧pale gray yellow
green”

63

Ratio of colors

The 2nd to 6th stage： with TRWKR,
no rain on the day and the previous day
the 7th to 16th stage： without TRWKR
no rain on the day and the previous dayfrom Sanage bridge to Minato-shin bridge

Colors were added to survey item from the 2nd stage.

Frequent colors : ⑧pale gray yellow green, ⑨gray yellow green, ⑩gray green
50

5th

6th

7th

41

40

3737

10 9

11

③yellow②milky
white

6
5
4 3
3
3
22 22 2 2 2
11 1 111 1⑫pale
yellow
gray

16th

⑪dark
gray

15th

15

⑩gray
green

14th

20

⑨gray
yellow
green

13th

⑧pale
gray
yellow…

12th⑦yellow
gray

11th

⑥gray

10th

⑤green9th④yellow
green

25

8th

①
colorlessratio(%)

30

035
33 3433
31
32
31
32
30
30
30
27
27
25
24 24
24
22
21
20
19
20
19
19
18
17
16 15 17
13
13
13
12 12
12
1213 12
12
11
10
10
10
11
9
9 9
8
6
7
6 7 7
6
6
6
6
6 5 56
6
65
5 4
4 5 6
5 55
5 4
5 5
5
44
4
4
3
5
44 3
3
3
3
4
3
3
3
3
3
3
3
32
2 2
3 2 222
2
31 2 22 3 1 1 2 121 1 2 3 3 3
22
2 21
22
1 11
1
1 1 111
1 111 2 1 1 111 0
01
0
34

35

5

41

1

⑯others

4th⑮greenbrown

3rd⑭brown2nd⑬yellowbrown

45

number of survey
2nd stage:213
3rd stage:176
4th stage: 52
5th stage:111
6th stage: 63
7th stage: 85
8th stage: 67
9th stage: 76
10th stage:113
11th stage:113
12th stage: 98
13th stage: 93
14th stage: 82
15th stage: 89
16th stage: 63■frequent colors?
→⑧pale gray yellow green, ⑨gray yellow green, ⑩gray green

64Change of colors(from spring to early summer)

The 7th, 8th, 11th, 13th, 15th stage: without TRWKR
no rain on the day and the previous day

Note: small number of survey data
Sakae bridge to Sanage-bashi
Sanage bridgefrom Sakae-bashi
0%10%

7th stage

20%

30%

40%

50%

60%

70%

80%

90%

100%

others, 60%

milky, 40%

number of survy: 5
9th stageothers, 100%number of survey:5
milky
11%
number of survey: 9
11th stage

13th stageothers, 89%

milky, 26%

legend■milky■red tide②milky white ⑬yellow brown⑧pale gray
⑭brownyellow green⑮green brown⑫pale yellow gray■sludge⑥gray⑩gray green⑪dark grayothers, 75%

number of survey: 8
15th stageothers, 100%number of survey: 7

Sanage bridge to Minato-shinbashi
bridgefrom Sanage-bashi
0%10%

7th stage

20%

30%

40%

50%

60%

70%

80%

milky, 28%

red tide9%

milky, 31%

red tide sludge
15%
3%others, 51%

sludge18%

others, 54%

sludge18%

90%

100%

■ change of colors after theintermit of TRWKR→From the spring to earlysummer, milky and red tide wereincreased and sludge wasdecreased, compare 15th stage
with 7th (right after intermit of
TRWKR).

others, 45%

number of survey:85
9th stage
number of survey:76
11th stage

milky, 19%

red tide9%

number of survey:113
milky,
13%
number of survey:93
13th stage

15th stage

red tide21%

milky, 40%

sludge34%

red tide15%

sludge7%others, 32%

others, 38%

number of survey:89

Note: 0% items omitted.

Ratio of Milky and red tide increased,
and that of sludge decreased.

65

Ratio of main colors(spring to early summer)
Hereafter NOB=Number Of Survey

bridge to Johoku-bashi
Sanage-bashi
bridge0%10%

7th stage

20%

30%

40%

50%

red tide4%

milky, 33%

60%

70%

sludge, 34%

80%

90%

sludge, 15%

milky, 40%30%

red tide
12%

40%

50%

60%

70%

sludge,
12%

80%

90%

100%

others, 56%

sludge,14%

milky, 27%

others, 59%

NOS:22

11th stage
NOS:2711th stageothers, 66%

milky, 34%

milky, 21%

red tide,sludge, 19%
5%milky, 20%

red tide, 14%others, 55%

NOS:43milky
12%

13th stage

red tide13%

13th stageothers, 50%

sludge, 25%

others, 34%

sludge, 32%

NOS:35

NOS16
15th stage

15th stageothers, 69%

milky, 31%

red tide sludge,
12%
6%

milky, 46%

others, 36%

NOS:34

NOS16

Ratio of red tide and sludge decreased.
bridgebridge to Asahi-bashi
johoku-bashi
Note: small number of data
0%

10%

20%

7th stage

30%

40%

50%

milky, 50%

60%

70%

80%

90%

Ratio of milky increased.
bridge to Oseko-bashi
bridgeMatsushige-bashi
0%

100%

7th stageothers, 50%

10%

20%

milky, 23%

30%

40%

50%

red tide10%

sludge
13%

60%

70%

80%

90%

100%

others, 54%

NOS:30

NOS:6
milky, 22%

sludge11%

9th stageothers, 67%

milky, 14%

red tide8%

milky, 32%

NOS:25

NOS:9
sludge, 36%

11th stageothers, 50%

milky
7%

red tide, 22%

others, 40%

sludge, 20%

others, 42%

sludge, 29%

NOS:27

NOS:14milky, 28%

red tide, 14%sludge, 44%others, 14%13th stage

milky
3%

red tide, 34%

sludge, 40%

others, 23%

NOS:35

NOS:7
15th stage

20%

milky, 20%

9th stageothers, 45%

NOS:2013th stage

10%

NOS:259th stage

11th stage

0%

7th stage

NOS:249th stage

Asahi-bashi
bridge to Matsushige-bashi
bridge100%

others, 29%

The 7th, 8th, 11th, 13th, 15th stage: without TRWKR
no rain on the day and the previous day

milky, 100%15th stage

milky, 26%

red tide, 26%

sludge, 15%

others, 33%

NOS:34

NOS:5■change of colors after stop of TRWKR
Ratio of red tide and sludge disappeared on the 15th stage from Asahi bridge to Johoku
bridge. Milky and sludge didn’t change and red tide increased in lower from Matsushige
bridge to Oseko bridge.

Ratio of red tide increased.
Note: 0% items omitted.

66

Change of colors(from autumn to early winter)
bridge to Sanage-bashi
bridgeSakae-bashi
0%

10%

20%

30%

8th, 10th, 12th, 14th, 16th stage: without TRWKRNo rain on the day and the previous day

Note: small number of data40%

8th stage

50%

60%

70%

80%

90%

100%

legend■milky■red tide②milky white ⑬yellow brown⑧pale gray
⑭brownyellow green⑮green brown⑫pale yellow gray■sludge⑥gray⑩gray green⑪dark grayothers, 100%

NOS:8
Mmilky11%

10th stageothers, 89%

NOS:9
12th stageothers, 100%

NOS:8
14th stageothers, 100%

NOS:7
16th stageothers, 100%

NOS:1

bridgebridge to Minato-shinbashi
Sanage-bashi
0%

8th stage

10%

20%

30%

40%

50%

red tide sludge
7%
7%

milky, 35%

60%

70%

80%

90%

100%

■change of colors after stop of
TRWKR→Ratio of milky decreased and sludge
increased compare 16th stage with 8th(right after intermit of TRWKR), from
Autumn to early winter.

others, 51%

NOS:6710th stage

milky, 31%

red tidesludge, 18%
5%others, 46%

milky, 30%

red tide4%

others, 48%

NOS:11312th stage
NOS:9814th stage

milky, 16% red tide6%

sludge18%

sludge, 27%

others, 51%

NOS:8216th stage

milky, 22%

red tide5%

sludge, 23%

NOS:63

Note: 0% items omitted.

others, 50%

Ratio of milky decreased and sludge increased.

67

8th, 10th, 12th, 14th, 16th stage: without TRWKRNo rain on the day and the previous day

Ratio of colors(Autumn to early winter)
Hereafter NOB=Number Of Survey

bridge to Johoku-bashi
bridgeSanage-bashi
0%

10%

20%

8th stage

30%

40%

50%

60%

70%

80%

sludge12%

milky, 51%90%

red tide sludge
10%
10%

milky, 25%

14th stage

milky, 18%

red tide, 18%

sludge, 24%

70%

80%

90%

100%

90%

100%

others, 48%

sludge, 26%

others, 39%

milky redd tide sludge
18%
2%
20%

14th stageothers, 40%

sludge8%

milky, 34%

0%16th stageothers, 58%

others, 60%

milky
16%

red tide ヘsludge
4%16%

others, 64%

milky
17%

red tide sludge,
3%6%others, 66%

NOS:29

10%

20%

30%

40%

50%

milky, 20%

60%

70%

Ratio of milky, red tide, and sludge decreased.
bridge to Oseko-bashi
bridgeMatsushige-bashi
80%

90%

0%

100%

8th stageothers, 80%

NOS:5

10%

20%

30%

milky, 29%

40%

50%

60%

70%

80%

others, 56%

red tide, 15%

NOS:21milky, 34%

sludge, 33%

others, 33%

10th stage

milky, 23%

sludge9%others, 68%

NOS:35

NOS:12
milky, 42%

others, 58%

NOS:12

12th stage

red tide4%

milky, 45%

sludge, 31%

others, 20%

NOS:26

milky, 28%

sludge, 36%

others, 36%

14th stage

milky red tide3%
14%others, 49%

sludge, 34%

NOS:29

NOS:11
16th stage

60%

NOS:40

Ratio of milky and sludge decreased.
bridge to Asahi-bashi
bridgeJohoku-bashi

14th stage

50%

red tide sludge,
8%
12%
red tide9%

milky, 26%

12th stageothers, 55%

NOS:12

12th stage40%

NOS:2516th stage

10th stage

30%

NOS:43

NOS:17

8th stage

20%

milky, 32%

10th stageothers, 26%

NOS:2312th stage
NOS:2010%

NOS:25

red tidesludge
8%
8%

milky, 58%

0%

8th stageothers, 37%

NOS:1610th stage

bridge to Matsushige-bashi
bridgeAsahi-bashi

100%

milky, 34%

sludge, 17%others, 49%

NOS:6

16th stage

milky, 19%

red tide13%

sludge, 49%

others, 19%

NOS:16■change of colors after stop of TRWKR
Ratio of milky and sludge were large on the 16th stage, from Sanage bridge to Johoku
bridge and from Asahi bridge to Matsushige bridge. However, there ratio trends todecrease. On the other hand, on the lower, ratio of milky decreased and sludge
increased from Matsushige -bridge to Oseko bridge. Red tide was 13%.

Ratio of sludge increased
and milky and red tide decreased.
Note: 0% items omitted.

68Frequency of finding Litters（From 2nd to 16th stage, all section）

６.８. Litters

From 2nd to 6th stage :With TRWKR No rain on the day and the previous day
From 7th to 16th stage :Without TRWKR No rain on the day and the previous day■Litters component：Plastic wastes(PE, plastic bag, noodle cup, foam tray,
pet bottle ,etc.), can, glass, cigarette (wrapping, butt)“PE shopping bag 1.8”means that PE
shopping bag was found 1.8 times in 10
investigations. (or 18 times in100
investigations)

Frequency of litters wasin decreasing trend .

■What kind of litters was found more frequency?
Cigarette butt was the most frequent.
The other litters was on decreasing trend .

69

From 2nd to 6th stage :With TRWKR No rain on the day and the previous day
From 7th to 16th stage :Without TRWKR No rain on the day and the previous day

Litters on Riverside Ways
（From 2nd to 16th stage, each section）(

plastic) Number of survey

With TRWKR

1st stage

canbottlepaper

cigarette■Litters component：
Plastic wastes(PE,plastic bag, noodle cup,
foam tray, tray, petbottle, etc.), can, glass,cigarette(wrapping, butt)

Plastics : in decreasing trend(No
2nd survey)
stage

42%

10% 6%(255)
3rd stage

40%

8% 1%

(191)
4th stage

43%

(54)
5th stage

32%

(90)
8th stage(75)
9th stage(81)
10th stage(122)
11th stage(122)
12th stage(106)
13th stage(101)
14th stage(89)
15th stage(96)
16th stage
(64)

9% 3%

27%

7% 2%

24%

7% 1% 15%

30%
28%
27%

20%

36%

16%

48%
53%

34%

8% 2%

18%

33%

8% 2%

24%

33%

30%

10% 5%

18%

37%

30%

7% 3%

33%

0%

21%

9% 1% 19%
7% 2%
27%

37%

(119)
6th stage(66)
7th stage

20%

22%

6% 4%

29%

8% 1%

29%

8% 4%

27%

8% 1%
20%

38%

18%

42%

14%

43%

19%

43%

24%

35%

20%
40%

44%

60%

Lots of butt
80%

100%

Component ratio(%)＝the number of sighting each kind of litter／the number of sighting all kind of litter ×１００
Litter does not include leaves, branches and grass.
＊The number of sighting is not the number of litters.
We count one, even if at least one litter is sighted in the survey.

■What kind of litters was found on the riverside ways more frequently? The
rate of cigarette was high. Plastics are in decreasing trend.

70Change in Floating Litters

From 2nd to 6th stage : With TRWKRNo rain on the day and the previous day

From 7th to 16th stage : Without TRWKR No
rain on the day and the previous day■Litters component：Plastic wastes(PE, plastic bag, noodle cup, foam tray,
pet bottle ,etc.), can, glass, cigarette (wrapping, butt)

16th stage
1.9litters/one survey
Rate of plastics is highThe sum of eachstage, thenumber of litters per
one survey

Note: the number of litters per one survey = the number of each litters found in all surveys/the number of surveys＊the number of litters is the number of litters found through all surveys“If some kind of litters was found “countless (=***)”in some survey, it counts “10”, the maximum number in one survey
substituted for the number of “countless”■What trend the floating litters goes?→The number of floating litters at 16th stage was
1.9litters/one survey. Rate of plastics was high.

71Change of the number of Floating Litters

From 1st to 6th stage :With TRWKR No rain on the day and the previous day
From 7th to 16th stage :Without TRWKR No rain on the day and the previous day

There were many floating litters In “Sanage Bridge ～Johoku Bridge” section and “Matsushige Bridge ～Oseko Bridge” section.

■In which section did a lot of litters float？
→ In “Sanage Bridge ～Johoku Bridge” section and “Matsushige Bridge ～Oseko Bridge” section.

72

Change in Floating Litters along the Horikawa River
The 1st-16thｓｔage: include both with TRWKR and without TRWKR out of research period ,No rain on the day and the privious day

There were a lot of litters
between Matsushige Bridge
and Oseko Bridge

There were a lot of littersaround Johoku Bridge

Around Matsushige Pumpimg
Station＊：Under 10 sumples

Note: the number of litters per one survey= the number of each litters found in all
surveys / the number of surveys＊the number of was found through all
surveys“If some kind of garbage was found“countless (=***)”in some survey,itcounts “10”, the maximum number in one
survey substituted for the number of“countless”

Kameya Bridge～Sumiyoshi Bridge•Photo: secretariat

73

Kind of floating Litters(component ratio)

With TRWKR■ Litters component：Plastic wastes(PE, plastic bag, noodle cup, foam tray,
pet bottle, etc.), can, glass, cigarette (wrapping, butt)

From 2nd to 6th stage :With TRWKR No rain on the day and the previous day
From 7th to 16th stage :Without TRWKR No rain on the day and the previous day

There were many prastic litters

Rate of litters(%)＝the number of each kind of litters ／the number of all kind litters×100
the number does not include leaves branches and grass＊the number of litters was found through all surveys“if some kind of litters were found ”countless (=***)”in some survey, it counts “10”, the maximum number in one
survey substituted for the number of “countless”。

■What kind of floating litters were found frequently?
→The rate of plastics is high, 60%(16th stage), in decreasing trend.

74

Living things found by Horikawa Sen-nin
Chosatai in 8 years(2007～2014)

６.９. Living things
Waterside, Surface of water
Birds(33）■ Many kinds of living things breeds→the self-cleansing action by food chain
Pollution（organic substance・Nitrogen・phosphorus, etc）

In water

Algae and microbes are spread by pollution■Common Indian kingfisher■Kinds of Cnowy heron
Little egret, Large egret, BlackFish, shrimp, insects eat algae, microbes
crowned night heron■Japanese common cormorant
Big fish and birds eat small fish and insects■Kinds of carp
■Kinds of duck
Crucian carp、Pale chub、
Spotbill duck, Pin-tailed duck
Tufted duck, Green-winged teal Goby minnow、Hemibarbus barbus、モツゴ■ＥelBluebill, Pochard■Flogs■CatfishMallard, Little grebe＊Introduced species
The sludge had piled up■Kinds of goby
■Black head gullAmerican Bullfrogin Horikawa River, and■Kinds of dragonfly
Common goby、■MoorhenDamselfly、Common skimmer
called “dead river” inEstuarine
goby、Rhinogobius■Wagtail
Pseudothemis zonata、Lesser emperor
1970s.
■Sea bass
Dishwasher, Japanese wagtail
But, the water quality■Striped mullet
Grey wagtail
improved gradually,■Chubmackerel■Blue rockthrush
16 kinds of fish, 4 kinds■Dotted gizzard shad
■Kinds of turtle■Common sandpiperof crustacea, 33 kinds＊Introduced species
Ｓｏｆｔ－ｓｈｅｌｌｅｄ ｔｕｒｔｌｅ■Bulbulof birds, etc were foundBlack buss、Bluegill、＊Introduced species■Japanese brown-thrush
around Horikawa river.
Northern snakehead、Mosquitofish、
Pond slider、Ｓｏｆｔ－ｓｈｅｌｌｅｄ ｔｕｒｔｌｅ■Pale thrush
We think that thisGarfish、Arowana、■Kinds of snake■Dusky thrush
restoration of ecosystem
Cichlid
Japanese rat snake■Redstartmeans the restoration of■Turtledove
the self-cleansing action■Japanese great titof Horikawa river.
■Japanese pygmy woodpecker■Kinds of crabs and shrimps■Oriental greenfinch
Grapsoidcrab、Japanesemitten crab、Palaemon adspersus、■Sparrow
Prawn■Sea lettuce, etc■Gray starling＊Introduced
species■Japanese white-eye
Green crab、American crawfish■Bush warbler

Fish（16）

Amphibians（1）Insects

Reptiles（2）Crustacea（4）Algae（1）

75

Fish
Carp

Crucian carp

■Kinds of carp
Pale chub
Goby minnow■EelJapanese barbel

Stone moroko
Gymnogobius urotaenia

Yellowfin goby

■Catfish■Sea bass■Striped mullet■Kinds of goby

Estuarine goby

Rhinogobius
76

Fishes■Chub mackerel＊Invasive Alien Species■Dotted gizzard shadBlack bass

Bluegill
Northern nakehead

Gambusia

Arowana

Fellow of Gars
A family of Cichlids

Crustaceans■A family of
crabs・shrimps
Chiromantes dehaani,Japanesemitten crab,common prawn,
Freshwater prawn

Chiromantes dehaani

Japanese mitten crab

＊Invasive Alien Species

Common prawn

Freshwater prawn A family of green crabs Red swamp crawfish
77

BirdsLittle egret■A family of herons
Grey heron, Little egret,Greategret,Night heron

Grey heron■Common kingfisher

Night heron■Great cormorant■A family of ducks
Spot-billed duck,Northern pintail
Tufted duck, Eurasian teal
Eurasian wigeon,Common pochard
Mallard, Little grebe

Spot-billed duck

Great egret
Northern pintail

Eurasian wigeon

Tufted duck

Eurasian teal

MallardLittle grebe

Common pochard

78

Birds■Black-headed gull

■Fellow of wagtailJapanese pied wagtail, Japanese wagtail,Gray wagtail■Common moorhen Japanese pied wagtail

Japanese wagtail■Common sandpiper

Gray wagtail■Blue Rock-Thrush■Brown-eared bulbul■Dusky thrush■Brown-headed thrush■Pale thrush■Daurian redstart■Japanese tit■Oriental turtle dove

■Japanese pygmy
woodpecker■Oriental Greenfinch

79

Birds■Japanese White-eye■Eurasian tree sparrow■Japanese bush warbler■White-cheeked starling

Reptiles■A family of snakes
Japanese rat snake
A family ofsoft-shelled turtles■A family of turtles
Chinese pond turtle,Soft-shelled turtle

Soft-shelled turtle

Chinese pond turtle

Amphibians＊Invasive Alien Species

Red-eared slider

Anax parthenope

Mammals Raccoon dog
Photographed on January 27, 2015
Photo by Satou family Horikawa Ouentai

Near Nakatsuchido Bridge＊Invasive Alien Species＊Invasive Alien Species

American bullfrog■Fellow of Dragonfly Atrocalopteryx atrata,Orthetrum albistylum,Pseudothemis zonata,,Anax parthenope

Insects
Atrocalopteryx atrata

Orthetrum albistylum

Pseudothemis zonata

80

６.１０. Wind

Direction of windWind to upstream

Meoto Bridgetouostream

Kitashimizu Bridgetouostream

14%

100
80
60
40

9%

20

from side0

Wind from side

20% downstre

56%

9%

No windfrom side

1st to 16th stage,
number of survey 64

100
80
60
40
20
0

No wind33%

20

downstream

40

from side

0

24%

20

No wind

1st to 16th stage,
number of survey 169

1st to 16th stage,
number of survey 66

12% downstrea

Oto Bridge

No wind10%
from side

100
80
60
40
20
0

to
uostream
100

9%

80
60

1st to 16th stage,
number of survey 84

33%

30%

to
uostream 32%

60

0

60

50%

Nishiki Bridge

80

from side

34%

m

to
uostream 11%

40

touostream
80

m

100

23%

Johoku Bridge

30%

100

11% downstreaam

Koshio Bridge

Wind blows frequently
along the Horikawa River

15%

7%

40

No windfrom side

0

30%

20

No wind

1st to 16th stage,
number of survey 136

1st to 16th stage,
number of survey 238

44% downstream

54% downstreamWind to downstream■Which direction?
We organized the data
through all surveys.The windblowing along the river weremore frequent than that fromside. At the Nishiki bridge, therate of winds blowing along theriver was about 80%.

81

【Information】
Kiso region is a fountainhead of the Kiso River, the water of life for Nagoya citizens.
Horikawa Sen-nin Chosatai is supporting Kiso region.
Brochure of Kisoji82

6.11. State of Shin-horikawa River
Impression of water pollution

Shin-horikawa River
Maizuru bridge

All data included

Kinen bridge

Impression of water pollution got worth between Uzura bridge and Oi bridge

92％

Uzura bridge

Oi bridge
Horagai bridge

92％
72％

number of data 22

5

24

35

24

3

Atsuta bridge■ Impression of water pollution
Component ratio of “dirty” and “slightly dirty” got morethan 90% at Uzura bridge and Oi bridge (upstream of
Shin-horikawa).
Impression of water pollution is bad between Uzura
bridge and Oi bridge.

83

Transparency of Shin-horikawa River
Low transparency at Oi bridge

Transparency in upstreamof Shi-horikawa river, at
Maizuru bridge and Kinen
bridge, was more than
70cm.It was acceptable
range of citizen. But it
was only 48cm at Oi bridge.

＊acceptable range for citizen: 70cm & over transparency
number of data

COD of Shin-horikawa River
17～19mg/L between Horagai biridge and Uzura bridge

High COD level was seen
between Uzura bridge andHoragai bridge.

number of data84

Bubbles of Shin-horikawa River
Many bubbles from river bottom were seen at Uzura bridge
Bubbles from river bottom were seenat Uzura bridge, Kinen bridge and Oi
bridge. No bubbles occur at otherbridges.

number of data

Smell of Shin-horikawa River
Terrible or bad smell occurred upstream,
between Maizuru bridge and Oi bridge.

Worth smell occurred between
Maizuru bridge and Oi bridge.

29％

36％

33％

33％

85

Kind of Smell from Shin-horikawa Riversmell of oil etc.
smell of sulfur

Ditch smell occurred widearea, and sludge and rotten
egg smell occurred on
upstream.

Sludge and rotten egg smell
occurred at Uzura bridge, Kinen
bridge and Oi bridge.

number of data

7

3

20

32

19

1

Colors of Shin-horikawa

Lighter colors were seen at
Uzura bridge and Kinen bridge.
Colloidal particulate sulfur
might cause these colors.
And darker green colors werefrom phytoplankton.

Lighter colors were seenat Uzura bridge and Kinen
bridge.

number of data86

6.12. State of Horikawa at total lunar eclipse (October 8, 2014)
Water level of Horikawa (tidal zone: Sanage Bridge - estuary)is changed by attraction of Moon and Sun, and rotation of Earth
Sun, Earth and moon are aligned in a straight line at lunar and solar eclipse
Attraction becomes stronger, change of tide increases
Geometry of total lunar eclipse

Partial eclipse
Total eclipse
Partial eclipse

Sun

Earth

Moon

Source) National Astronomical Observatory of Japan87

Source) The Nagoya City Science Museum

Scene of Total Lunar Eclipse

Total eclipse was available toobserve from Naya bridge andNishiki bridge.

Photos by secretariat
18時45分頃
19時頃

19時頃

20時30分頃88

State of Horikawa at Total Lunar Eclipse(October 8, 2014)
Point of investigation
Investigation placed in comparison with partial solar
eclipse (July 2009) and annular solar eclipse (May2012).
■ Color, smell and bubble of water① Run-up of blue tide and red tide② Raised up of sludge on riverbed③ Bubbles from river bottom■ Other changes① State of creatures② State of floating litters at tip of tide89

Tidal level （T.P.cm）

18th typhoon passed through October 5 to 6, total precipitation recorded 60mm
Tidal level(T.P.cm）

200
150
100
50
0
-50
-100
-150
-200

Material) Japan
Meteorological
Agencyprecipitation（mm/h）

0
10
20
30

Total Lunar Eclipse on October 8
2

3

4

5

6

date

7

8

9

40

10

Precipitation （mm/h）

Tidal Change on Nagoya Port (2 to 16 October)

11

Details of change on October 8

Difference 206cm(reference) differenceon annular eclipse :116cm

Total lunar eclipse

Annular eclipse(October 8, 2014)(May 21, 2012)

Difference 224cm(reference) differenceon annular eclipse :204cm

Tidal level changed by more than 2m
90Summary of Effects under Total Lunar Eclipse■Colors, smell, bubbles■Other changes① Run-up of blue tide and red tidewere not seen. Because it was cooler season than the other case of
eclipse, and 18th typhoon brought heavy
rain and it supply fresh water into Horikawa river.

① State of creatures
was normal. No fish was seen breathing withdifficulty.

② State of floating litters at tip of tide② Raised up of sludge on riverbed

was like under other eclipse. Litters were seen
between Sakura bridge and Nayabashi bridge

were seen between Asahi bridge and Matsushige bridge. Tidal levelchange might be increased by eclipse.

③ Bubbles from river bottom
were not seen. Reason for it suggested in common with colors.

Comparison of simultaneous investigation during eclipse
State of Horikawa
blue tide and red tide
area

partialeclipseJul-09annulareclipseMay-12

Sanage biridge Johoku bridge-

Johoku bridge Asahi bridge

-

total
eclipseOct-15sludgeannulareclipseMay-12

total
eclipseOct-15

partialeclipseJul-09○--Matsushige bridge- Ooseko biridge-○

bubblesannulareclipseMay-12

total
eclipseOct-15

partialeclipseJul-09○-Asahi bridge ○○Matsushige bridge blue tide red tide○
red tide

partialeclipseJul-09other changes

○

-

○

○

-

-

○

creatureannulareclipseMay-12

total
eclipseOct-15floating litterspartialannulartotal
eclipse eclipse eclipse
Jul-09
May-12 Oct-15

-

-

○

-

○

-

-

○
mullet *--○mullet--○mullet* breath with difficulty○
Tenma Nayabridge--○Tenma Nayabridge○Tenma Nayabridge--91

■Earth Club Survey Group■Water color andBubbles

Date ： October 8th, 2014
Time ： 15:30 ～ 17:30
Place ： Goryo Bridge ～Sumiyoshi Bridge

There were bubbles on thesurface of the river near
Kameya Bridge.
And water color changed atright side of downstream
from Kameya Bridge.
It was supposed to becaused by ship passing .

Earth Club Survey Group

15:36, high tideto downstream①Goryo Bridge③Kameya Bridge
16:50, high tide
Water color changed

Bubbles occurred

to upstream
high tide②Hataya Bridge
16:35, high tidefish is jumping■ Living things
Fish was jumping onto thewater at Hataya Bridge. Water
color looked unusual becauseof a big school of fish at left
side of downstream from
Sumiyoshi Bridge.

④Sumiyoshi Bridge
17:14, high tideto downstream92■Survey by Secretariat
Nishiki Bridge
to upstream
9:02, ebb tide

Date ： October 8th, 2014
Place : Naka Bridge ～ Oto Bridge

Tenma Bridge

Secretariat

Nishiki Bridge Tenma Bridge
to upstream
12:16, ebb tide

Nishiki Bridge
to upstream
13:23, ebb tide

Tenma Bridge

Sakura Bridge Naka Bridge
to upstream
12:23, ebb tide

Secretariat

Naka Bridge Gojo Bridge
to upstream
12:25, ebb tide

■Near Nishiki Bridge at ebb tide time
There were no changes of water color,
smell and bubbles.
93

■Between Nishiki Bridge
and Oto Bridge at high tide

Secretariat

Nishiki Bridge Tenma Bridge
to upstream
14:46, high tide

We went and returned between Nishiki
Bridge and Oto Bridge on foot toobserve the river at high tide time.
Sludge was raised up from the bottom
at about 15:00 between Tennozaki
Bridge and Hioki Bridge.

Near Naya Bridge
to upstream
14:54, high tide

Sludge was raised up.
新洲崎橋
Suzaki Bridge
Shinsuzaki Bridge
to upstream
15:11, high tide

Sludge was raised up.

Iwai Bridge
to upstream Suzaki Bridge
15:19, high tide

Sludge was raised up.

Tenno Bridge
to upstream
14:59, high tide

Sludge was raised up.
Iwai Bridge

Hioki Bridge
to upstream
15:27, high tide

Sludge was raised up.

94

Hioki Bridge

Matsushige Bridge
to upstream
15:34, high tide

Furuwatari Bridge
to upstream
16:02, high tide

Oto Bridge
to downstream
16:16, high tide

Matsushige Bridge
to downstream
15:36, high tide

Near Sanno Bridge
to upstream
15:45, high tide

Near railway bridgesof ＪＲ and Meitetsu
16:10, high tide

Oto Bridge
to upstream
16:14, high tideNaya Bridge
to upstream
17:22, high tide Nishiki Bridge

Nishiki Bridge
Tenma Bridge
to upstream
17:37, high tiderailway bridgesof ＪＲ and Meitetsu

ship was running95

■Living things

Near Matsushige Lock Gate at about 15:40

A school of mullet was lively swimming at the left side

■Tip of tide

To upstream from Nishiki Bridge, at about 17:30

Suspended substance was accumulated at the point (supposedly the tip of the flow of the tide)
between Tenma Bridge and Sakura Bridge at about 17:30, and moved to downstream near NayaBridge at about 18:30.

Tenma Bridge

Tenma Bridge

suspended substanceto upstream from Nishiki Bridge

suspended substanceto downstream from Sakura Bridge96

■Mechanism which suspended substance is accumulated

Tenma Bridge
sea
water

suspended substance at about 17:30

Sakura Bridge

Sea water is pushed up by strong up-flowing of high tide.
The tip meets fresh water and junction line occurs.
→Suspended substance is accumulated at the junction line.

fresh
water

(Reference) Report from the 11th survey meeting, pp14,15 “solar eclipse”

97Tidal level of Nagoya Port on October 8th
Data: the website of Japan Meteorological Agency

Kawasemi Survey GroupHigh tide

Kojo Horikawa to Seikatsu wo Kanngaeru Kai

Ebb tide

Secretariat

Secretariat

Earth Club Survey Group
Mizu Mondai Kenkyujo Suｒvey Group①Change of flow direction on October 8th
6

7

8

9

10

11

12

13

upstream

JohokuGojo
NishikiNaya
Sanno
Sumiyoshi
KameyaHatayaAtsuta Kinen
downstream Goryo＊：observed by secretariat

14

15

16

17

18

↑
↓
↓
↓
↓

↑*
↑*

↓*
↑*
↑
↑

↓
↑
↑
↑

Ebb tideHigh tide

19

20

Water was flowing
to downstream at
Nishiki Bridge at
13:00 though it
was high tide at
Nagoya Port.
Water became ebb
tide at NayaBridge at about
18:30

Ebb tide98

②Impression of Water Clearness
1：Clean 2：Slightly clean 3：Ordinary 4：Slightly dirty 5：Dirty

6

7

8

9

upstream Johoku

10

11

12

13

14

15

16

17

18

19

20

2↑

Gojo
NishikiNaya
Sanno
Sumiyoshi
KameyaHatayaAtsuta Kinen
downstream Goryo

3↓
4↓“Slightly dirty”
at Nishiki Bridge andNaya Bridge.
“Clean” and“Ordinary” between
Sanno Bridge andGoryo Bridge.

4↓
3↓
1↑
3↑

2↓
3↑
3↑
1↑

③Change of Water Color
7:Yellow gray, 9:Gray yellow green, 10:Gray green, 11：Dark gray, 12:Light yellow gray, 15:Green brown
6
7
8
9
10
11
12
13
14
15
16
17
18 19

upstream

JohokuGojo
NishikiNaya
Shinsuzaki～Hioki

20

12↑

“Green Brown”
at Gojo Bridge“Gray yellow green”
at Nishiki Bridge andNaya Bridge

Sanno
Sumiyoshi
KameyaHatayadownstream Atsuta Kinen
Goryo＊：observed by secretariat

15↓

9↓ 7↑*
9↓

7↑*
11↑*

10↓

7↓

Sludge was raised up andwater color is “Dark gray”
between Shinsuzaki Bridgeand Hioki Bridge

10↑*“Gray green”
at Sanno Bridge andGoryo Bridge

10↑
10↑
10↑
10↑
10↑

Raising up ofsludge was foundbut Red Tide andBlue Tide were
not found.

・”Green brown” and “Dark gray” at ebb tide time at Gojo Bridge and between
Shinsuzaki Bridge and Hioki Bridge. It was because sludge was raised up.
・“Gray yellow green” at Nishiki Bridge and Naya Bridge
・“Gray green” between Sanno Bridge and Goryo Bridge.

99

④Change of Smell
1：No smell 2：Slight smell 3：Smell 4：Bad smell 5：Terrible smell

6

upstream

downstream

7

8

9

JohokuGojo
NishikiNaya
Sanno
Sumiyoshi
KameyaHatayaAtsuta Kinen
Goryo
Oi

10

11

12

13

14

15

16

17

18

19

20

1↑
1↑

Smell of “Dich”
at Nishiki
Bridge andno smell atother points.

1↑
1↓
2↓
1↓
1↓
1↓
1↑
1↑
1↑
2↓

⑤Change of Transparency and COD
Ebb tideHigh tideHigh transparency

Low transparency at Gojo Bridge

Low ＣＯＤ
ＣＯＤ is high at Nishiki Bridge
and Naya Bridge

・At ebb tide timetransparency was
low especially at
Gojo Bridge and
COD was high at
Nishiki Bridge andNaya Bridge.
・At high tide timetransparency and
COD is better thanat ebb tide time.

100

大垣市
６.１３. Progress of Citizen’s Awareness 全国水都ネットワークフォーラム
平成２６年１０月１７日（金）Activities of studies

中日新聞 朝刊
平成２６年１１月７日（金）中日新聞 平成２６年９月２８日（日） 朝刊

木曽三川下流域の豊かな恵みと治水「流域住民現場見学会」
平成２６年１１月１日（土）主催：国土交通省
木曽川下流河川事務所

ＥＳＤ世界会議開催
平成26年11月9日（日）・11日（火）報告：御用水跡街園
愛護会調査隊

堀川１０００人調査隊2010 第１５回調査隊会議
平成２６年９月２７日（土) 報告：事務局

101

Activities of “Free Survey Groups” & “CheeringGroups”
秋の堀川一斉大そうじ
主催：クリーン堀川
平成２６年９月２０日（土）報告：御用水跡街園愛護会調査隊・事務局

御用水跡街園にチュ-リップの球根を植える
生活支援センタ-「なないろ」の皆さん
平成２６年９月３０日（火）報告：御用水跡街園愛護会調査隊

伊勢湾流域圏再生ネットワークにも加入されている
矢田川・庄内川をきれいにする会
平成26年９月２１日（日） 新聞記事より
駅ちかウォーキング
平成２６年１０月４日（土）報告：御用水跡街園愛護会調査隊

EM菌で堀川浄化大作戦 堀川ＥＭクラブ
平成２６年１０月２３日（木）報告：御用水跡街園愛護会調査隊

第３回鯱城・堀川清掃大作戦 平成２６年１１月８日（土）報告：御用水跡街園愛護会調査隊

102

Activities of “Free Survey Groups” & “CheeringGroups”
中日新聞 平成２６年１１月２５日(火）朝刊

第13回北区ふれあいウォーキング大会「黒川の魅力なるほど発見ウォーク」
主催：北区役所 平成２６年１１月１５日（土） 報告：御用水跡街園愛護会調査隊

堀川ギャラリー 成果報告のパネル展示会開催
鯱城・堀川と生活を考える会調査隊
平成２６年１１月１８日（火）～１２月７日（日）報告：御用水跡街園愛護会調査隊、事務局

定点観測・清掃活動
中日本建設コンサルタント(株)かわせみ調査隊
書籍 「都市と水を巡って」
堀川応援隊 山田雅雄さん（元・名古屋市副市長）が発刊
読売新聞 朝刊
平成２６年１２月２６日（金）朝日新聞 朝刊
堀川の歴史をたどる、浮世絵や写真を堀川ギャラリーで紹介
平成２６年１２月２５日（木）期間： 平成２６年１２月９日（火）～平成２７年１月４日（日）主催： 堀川文化探索隊
中日新聞 平成２６年１２月１２日（金） 朝刊

103

Activities of “Free Survey Groups” & “Cheering Groups”

活動報告 「上流は下流を思い、下流は上流に感謝する」
水源の里を守ろう 木曽川流域みん・みんの会

中日新聞 朝刊 平成２６年１１月３０日（日）中日新聞 朝刊
平成２６年１１月２８日(金）

活動レポート
環境ボランティアサークル「亀の子隊」

活動レポート
伊勢湾流域圏再生
ネットワーク事務局

104

Horikawa Clean Experiment of Chinese water spinach 2014/6/22～11/5
Ena agricultural High School and Nagoya Horikawa Lions Club experimented this year. Place：near the pier of Naya Bridge
第１週間目 ６月３０日

第５週間目 ７月２８日

第２週間目 ７月７日

第６週間目 ８月５日

第３週間目 ７月１４日

第７週間目 ８月１１日

第４週間目 ７月２２日

第８週間目 ８月１８日

105

第９週間目 ８月２５日

第１３週間目 ９月２２日

第１７週間目 １０月２１日
空芯菜の花

第１０週間目 ９月１日

第１４週間目 ９月２９日

第１８週間目 １０月２８日

第１１週間目 ９月８日

第１５週間目 １０月６日

第１９週間目 １１月５日

第１２週間目 ９月１６日

第１６週間目 １０月１４日

Mullet, company of goby,
mosquitofish, Japanese mittencrab, grapsoid crab,
Lycaenidae, Anax parthenope,
dragonfly was observed at atest site.
This means that Horikawa isimproving gradually and manykinds of living things caninhabit and breed at thewater’s edge of Horikawa.

モクズガニの抜け殻

カダヤシ

ベンケイガニ106

Events
秋の環境デーなごや
堀川ウォーターマジックフェスティバル
平成２６年９月１３日（土）平成２６年１０月１１日（土）～１２日（日）参加：名古屋堀川ライオンズクラブ
中日新聞 平成２６年１０月１２日（日） 朝刊
名古屋市高年大学環境学科２８期
報告：御用水跡街園愛護会調査隊・事務局

やっとかめ文化祭 「歴史まち歩き」
黒川駅から御用水跡街園の歴史散歩
平成２６年１１月９日（日）報告：御用水跡街園愛護会調査隊

上下流交流会 下呂市馬瀬地区
平成２６年１０月２５日（土）参加：インターネットフォーラム実行委員
・鯱城・堀川と生活を考える会の有志
なごや北ホームニュース

ＥＳＤユネスコ世界会議 併催イベント「みんなの環境ひろば」
平成２６年１１月１０日（月）～１２日（水）107

Events
第８回 木曽三川がつなぐ山とまち インターネットフォーラム開催
長野県木曽郡・木祖村木祖村民センターで開催
企画・実施：木曽三川がつなぐ山とまちインターネットフォーラム実行委員会
掘川１０００人調査隊２０１０実行委員会 共催
特別協賛：アサヒビール株式会社 一般社団法人、中部地域づくり協会
平成２６年１１月２２日（土）報告：御用水跡街園愛護会調査隊・事務局

This event expanded
the civic exchange
between upstream anddownstream area ofKiso River.
115 from Nagoya and 45
from Kiso attended thisevent.

市民タイムズ
平成２６年
１１月２５日（火）108