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- Results of Water Quality Environment Survey
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Results of Water Quality Environment Survey
Last updated on March 13, 2019.
Results of Water Quality Environment Survey
In 2002, the Yokohama City Environmental Conservation Bureau (now Sewerage and Rivers Bureau) conducted a survey of rivers in the city.
Based on the Yokohama City Water Environment Plan in 1993, Yokohama City established water area divisions and set achievement targets for each category.
The Hayabuchi River is considered to be a "clean" water area in the water area category 2A and the "upstream to downstream area".
The results of this survey indicate that the water environment targets have been achieved.
| Items | Measurement value | Unit | Remarks |
|---|---|---|---|
| Temperature | 32.0 | ℃ | - |
| Water temperature | 28.8 | ℃ | - |
| pH | 8.8 | - | - |
| Electric conductivity EC | 395 | μS/cm | - |
| Permeability | 53 | cm | - |
| Eh: Water | 375 | mV | - |
| Eh: Bottom quality | 335 | mV | - |
| Dissolved oxygen DO | 15 | mg/L | The amount of oxygen dissolved in water. It is said to be "beautiful" at 9mg/L or more. 3mg/L is required to live fish. |
| Biochemical Oxygen Demand BOD | 1.8 | mg/L | The amount of oxygen used by microorganisms to decompose dirt in water. If it is less than 1mg/L, "beautiful". Estimated odor is likely to occur if it is 10mg/L or more. |
| Ammonia nitrogen NH4-N | 0.020 | mg/L | The following items up to phosphoric acid are used as a guide for the flow of fertilizers, etc. |
| Nitrite nitrogen NO2-N | 0.079 | mg/L | The environmental standard is 10 mg/L or less. |
| Nitric acid nitrogen NO3-N | 1.10 | mg/L | The environmental standard is 10 mg/L or less. |
| Total inorganic nitrogen T-N | 1.19 | mg/L | - |
| Phosphate phosphorus PO4-P | 0.013 | mg/L | - |
| Flow speed | 83 | cm/s | - |
| Illuminance (inside) | 26000 | - | - |
| Illumination (outside) | 28000 | - | - |
| Contrast | 93 | % | - |
| Water depth: Algae | 15 | cm | - |
| Water depth: Insect | 15 | cm | - |
| Water depth: The maximum fish | 40 | cm | - |
| Flow width | 10 | m | - |
| Bottom quality: Algae | Gravel, sand | - | - |
| Bottom quality: Insect | Gravel, sand | - | - |
| Bottom quality: Fish | Gravel, sand | - | - |
| River form: Overall | Abyss | - | - |
| River form: Algae | Current | - | - |
| River form: Insect | Current | - | - |
| River form: Fish | Se, Fuchi, Sotsuki | - | - |
| Revetment form (total) | Steel sheet pile | - | - |
| Su (Others) | Yorisu (gravel) | - | - |
Inquiries to this page
Ward Administration Promotion Division Planning and Adjustment Section
Phone: 045-948-2225・2226・2227
Phone: 045-948-2225・2226・2227
Fax: 045-948-2399
E-Mail address [email protected]
Page ID: 637-753-729
