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- Preliminary results of water quality measurement in rivers (FY2021)
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Preliminary results of water quality measurement in rivers (FY2021)
This page shows trends in the monthly average value of hydrogen ion concentration (pH), biochemical oxygen demand (BOD), suspended matter mass (SS) and dissolved oxygen (DO) measured at 11 points in rivers based on the public water quality measurement plan formulated by Kanagawa Prefecture. Note that the measured values are preliminary values and may be corrected at a later date during the data confirmation process.
Last update date April 1, 2024
Click here for the layout of the measurement point.
Average of Rivers
Hydrogen ion concentration
| Name of water area | Name of River | Name of measurement point | Environment Criteria Type |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
1 |
2 |
3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tsurumi River | Tsurumi River | Sendai Bridge | Ｄ | 8.0 | 8.1 | 8.0 | 8.0 | 8.7 | 8.4 | 8.1 | 8.3 | 7.9 | 7.9 | 7.8 | 7.8 |
| Onda River | Miyakobashi Bridge | Ｄ | 7.8 | 7.8 | 7.7 | 7.8 | 8.2 | 8.0 | 7.8 | 7.8 | 7.7 | 7.8 | 7.7 | 7.7 | |
| Irie River | Irie River | Irie Bridge | Ｂ | 7.6 | 8.3 | 8.1 | 7.4 | 8.0 | 8.2 | 7.6 | 7.5 | 7.7 | 8.0 | 7.5 | 7.8 |
| Katabira River | Katabira River | Suidobashi | Ｂ | 8.1 | 8.2 | 8.0 | 8.0 | 8.1 | 8.2 | 8.0 | 8.0 | 7.9 | 8.2 | 8.3 | 8.1 |
| Ookagawa | Ookagawa | Shimizu Bridge | Ｂ | 8.1 | 8.2 | 7.8 | 7.8 | 8.1 | 8.1 | 7.9 | 7.9 | 7.6 | － | 8.2 | 8.3 |
| Miyakawa | Miyakawa | Seto Bridge | Ｂ | 8.1 | 8.0 | 8.0 | 7.9 | 8.0 | 8.2 | 8.0 | 8.0 | 8.0 | 8.2 | 8.2 | 8.2 |
| Samurai River | Samurai River | Hiragata Bridge | Ｂ | 8.2 | 8.0 | 8.6 | 8.2 | 8.2 | 8.6 | 8.1 | 8.0 | 7.9 | 8.4 | 8.2 | 8.2 |
| Sakaigawa | Sakaigawa | Takakamabashi | Ｄ | 8.1 | 8.1 | 7.6 | 7.8 | 7.7 | 7.8 | 7.8 | 7.8 | 7.8 | 7.9 | 7.9 | 8.0 |
| Kashio River | Yoshikura Bridge | Ｃ | 8.2 | 7.9 | 8.2 | 8.1 | 8.1 | 8.2 | 8.2 | 8.3 | 8.0 | 8.4 | 8.6 | 8.4 | |
| Kashio River | Hawkshobashi | Ｃ | 7.7 | 8.3 | 7.4 | 7.7 | 7.6 | 7.7 | 7.4 | 7.6 | 7.7 | 7.7 | 7.4 | 7.5 | |
| Itachi River | Itachigawa Bridge | Ｃ | 7.9 | 8.0 | 7.8 | 7.9 | 7.9 | 7.9 | 7.8 | 7.9 | 7.6 | 7.9 | 7.5 | 7.6 |
Bio oxygen consumption (BOD)
| Name of water area | Name of River | Name of measurement point | Environment Criteria Type |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
1 |
2 |
3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tsurumi River | Tsurumi River | Sendai Bridge | Ｄ | 2.7 | 5.0 | 2.6 | 0.7 | 1.0 | 1.8 | 1.0 | 0.8 | 2.4 | 7.1 | 9.5 | 9.9 |
| Onda River | Miyakobashi Bridge | Ｄ | 4.1 | 5.5 | 3.3 | 1.9 | 3.5 | 2.7 | 1.7 | 2.2 | 2.2 | 7.5 | 8.2 | 11 | |
| Irie River | Irie River | Irie Bridge | Ｂ | 1.7 | 4.9 | 18 | 2.2 | 3.2 | 2.6 | 1.9 | 1.3 | 0.8 | 1.2 | 1.5 | 1.6 |
| Katabira River | Katabira River | Suidobashi | Ｂ | 1.1 | 0.9 | 0.9 | 1.0 | 0.6 | 0.7 | 0.6 | 0.7 | 0.8 | 0.5 | 1.6 | 1.0 |
| Ookagawa | Ookagawa | Shimizu Bridge | Ｂ | 1.8 | 2.5 | 1.8 | 1.6 | 3.1 | 1.5 | 3.6 | 4.3 | 6.5 | － | 1.1 | 1.4 |
| Miyakawa | Miyakawa | Seto Bridge | Ｂ | 1.1 | 1.1 | 1.1 | 0.7 | 1.8 | 1.2 | 0.7 | 0.7 | 1.2 | 1.0 | 0.8 | 0.7 |
| Samurai River | Samurai River | Hiragata Bridge | Ｂ | 2.3 | 1.6 | 3.7 | 2.3 | 2.8 | 2.0 | 1.8 | 0.8 | 0.7 | 1.2 | 0.9 | 1.0 |
| Sakaigawa | Sakaigawa | Takakamabashi | Ｄ | 1.1 | 1.3 | 0.6 | 0.5 | 1.5 | 0.9 | 0.8 | 0.5 | 1.0 | 1.2 | 1.8 | 2.1 |
| Kashio River | Yoshikura Bridge | Ｃ | 0.6 | 1.0 | 0.6 | 0.5 | 2.0 | 1.2 | 0.7 | 0.4 | 1.3 | 0.5 | 1.0 | 1.3 | |
| Kashio River | Hawkshobashi | Ｃ | 2.1 | 1.9 | 1.4 | 1.4 | 1.8 | 1.4 | 1.4 | 1.2 | 2.0 | 6.3 | 2.8 | 3.2 | |
| Itachi River | Itachigawa Bridge | Ｃ | 3.7 | 1.4 | 0.6 | 0.7 | 1.1 | 0.8 | 1.1 | 0.9 | 1.3 | 4.2 | 2.4 | 3.6 |
Suspended matter mass (SS) ： (mg/l)
| Name of water area | Name of River | Name of measurement point | Environment Criteria Type |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
1 |
2 |
3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tsurumi River | Tsurumi River | Sendai Bridge | Ｄ | 5 | 5 | 3 | 3 | 3 | 4 | 2 | 2 | 2 | 4 | 8 | 9 |
| Onda River | Miyakobashi Bridge | Ｄ | 3 | 4 | 4 | 3 | 8 | 5 | 3 | 2 | 3 | 3 | 14 | 14 | |
| Irie River | Irie River | Irie Bridge | Ｂ | 4 | 5 | 16 | 3 | 8 | 4 | 3 | 3 | 1 | 1 | 2 | 4 |
| Katabira River | Katabira River | Suidobashi | Ｂ | 3 | 3 | 3 | 4 | 3 | 2 | 2 | 3 | 3 | 2 | 4 | 3 |
| Ookagawa | Ookagawa | Shimizu Bridge | Ｂ | 4 | 4 | 4 | 3 | 8 | 3 | 4 | 3 | 4 | － | 2 | 4 |
| Miyakawa | Miyakawa | Seto Bridge | Ｂ | 2 | 2 | 4 | 1 | 2 | 1 | 1 | 1 | 1 | 2 | 1 | <1 |
| Samurai River | Samurai River | Hiragata Bridge | Ｂ | 5 | 3 | 7 | 4 | 5 | 5 | 3 | 1 | 1 | 1 | 1 | 1 |
| Sakaigawa | Sakaigawa | Takakamabashi | Ｄ | 2 | 3 | 1 | 3 | 1 | 2 | 10 | 1 | 1 | 1 | 4 | 7 |
| Kashio River | Yoshikura Bridge | Ｃ | 2 | 4 | 7 | 2 | 12 | 6 | 3 | <1 |
2 | 1 | 1 | 3 | |
| Kashio River | Hawkshobashi | Ｃ | 2 | 2 | 3 | 2 | 3 | 3 | 2 | 2 | 2 | 2 | 2 | 3 | |
| Itachi River | Itachigawa Bridge | Ｃ | 2 | 2 | 2 | 4 | 4 | 2 | 2 | 3 | 1 | 2 | 2 | 4 |
Dissolved oxygen amount (DO)
| Name of water area | Name of River | Name of measurement point | Environment Criteria Type |
4 |
5 |
6 |
7 |
8 |
９ |
10 |
11 |
12 |
1 |
2 |
3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tsurumi River | Tsurumi River | Sendai Bridge | Ｄ | 10.6 | 10.8 | 9.1 | 9.0 | 11.0 | 11.8 | 9.4 | 11.3 | 10.6 | 10.8 | 10.4 | 9.7 |
| Onda River | Miyakobashi Bridge | Ｄ | 7.7 | 7.8 | 7.6 | 7.9 | 9.3 | 9.2 | 8.7 | 9.0 | 9.6 | 9.6 | 9.6 | 8.3 | |
| Irie River | Irie River | Irie Bridge | Ｂ | 7.3 | 11.9 | 11.0 | 4.4 | 7.2 | 9.2 | 6.4 | 5.5 | 6.8 | 7.5 | 8.4 | 9.8 |
| Katabira River | Katabira River | Suidobashi | Ｂ | 9.3 | 9.5 | 8.6 | 8.8 | 7.8 | 9.0 | 8.8 | 9.9 | 10.2 | 12.4 | 12.3 | 11.1 |
| Ookagawa | Ookagawa | Shimizu Bridge | Ｂ | 8.6 | 9.4 | 4.9 | 5.2 | 6.3 | 8.6 | 6.5 | 8.4 | 6.2 | － | 11.8 | 10.4 |
| Miyakawa | Miyakawa | Seto Bridge | Ｂ | 9.2 | 7.4 | 6.5 | 7.4 | 5.9 | 8.7 | 7.5 | 8.0 | 8.3 | 10.5 | 11.7 | 11.1 |
| Samurai River | Samurai River | Hiragata Bridge | Ｂ | 10.0 | 7.3 | 14.5 | 8.0 | 7.4 | 10.4 | 7.2 | 8.5 | 8.1 | 12.5 | 11.9 | 11.6 |
| Sakaigawa | Sakaigawa | Takakamabashi | Ｄ | 11.4 | 10.8 | 8.2 | 8.9 | 8.2 | 9.3 | 9.5 | 9.9 | 9.9 | 11.1 | 11.2 | 11.1 |
| Kashio River | Yoshikura Bridge | Ｃ | 11.8 | 11.0 | 10.0 | 9.8 | 9.2 | 10.8 | 10.4 | 11.9 | 12.0 | 14.4 | 15.3 | 12.4 | |
| Kashio River | Hawkshobashi | Ｃ | 8.7 | 8.6 | 8.1 | 8.0 | 7.6 | 8.6 | 7.9 | 8.4 | 8.4 | 7.7 | 7.9 | 8.1 | |
| Itachi River | Itachigawa Bridge | Ｃ | 9.5 | 9.0 | 8.5 | 8.8 | 7.1 | 8.2 | 8.8 | 8.6 | 9.0 | 8.8 | 9.0 | 9.1 |
Inquiries to this page
Environmental Pollution Monitoring Center, Environmental Management Division, Environmental Protection Department, Green Environment Bureau
Telephone: 045-671-3507
Telephone: 045-671-3507
Fax: 045-681-2790
Email address: mk-kankyokanri@city.yokohama.lg.jp
Page ID: 321-796-518
