Executive summary
Good during the monitored period
DO averaged 7.98 mg/L, the 5th percentile was 7.84 mg/L, and the minimum was 7.55 mg/L. Maximum ammonia/ammonium was 0.63 mg/L. This rating is a screening interpretation, not a regulatory ecological-status classification.
- Overall river-health screening rating: Good during the monitored period.
- Lowest DO was 7.55 mg/L at 2026-10-23 04:00:00; mean DO was 7.98 mg/L.
- The strongest DO relationship is typically water temperature: in this dataset r = -0.06, meaning warmer water coincided with lower oxygen.
- Ammonia/ammonium is also strongly associated with lower DO: r = 0.08.
- Diurnal behaviour is visible: average DO is lowest at about 04:00 and highest at about 15:00.
- Largest turbidity spike was 16198.32 NTU at 2026-10-12 02:00:00.
- Largest rainfall hour was 6.80 mm at 2026-08-17 23:00:00.
Note: This is an analytical screening report. It supports investigation and operational decision-making, but it is not a formal regulatory classification.
Water-quality and weather summary
| count | mean | std | min | 25% | 50% | 75% | max | |
|---|---|---|---|---|---|---|---|---|
| Ammonia/ammonium (mg/L) | 3690.00 | 0.32 | 0.06 | 0.14 | 0.26 | 0.32 | 0.35 | 0.63 |
| Conductivity (µS/cm) | 3690.00 | 381.13 | 32.11 | 159.29 | 364.83 | 390.15 | 405.53 | 432.72 |
| Dissolved oxygen (mg/L) | 3690.00 | 7.98 | 0.11 | 7.55 | 7.92 | 7.98 | 8.03 | 9.06 |
| Dissolved oxygen saturation (%) | 3690.00 | 97.57 | 2.67 | 88.97 | 95.81 | 97.27 | 98.90 | 111.89 |
| pH | 3690.00 | 10.23 | 0.58 | 8.52 | 9.85 | 10.14 | 10.54 | 12.59 |
| Water temperature (°C) | 3689.00 | 13.26 | 2.34 | 7.86 | 11.52 | 13.57 | 15.05 | 19.59 |
| Turbidity (NTU) | 3690.00 | 31.98 | 362.17 | 4.03 | 8.41 | 10.19 | 12.32 | 16198.32 |
| Air temperature (°C) | 3690.00 | 14.79 | 5.36 | 1.10 | 11.20 | 14.60 | 18.00 | 33.40 |
| Humidity (%) | 3690.00 | 73.54 | 16.88 | 22.00 | 61.00 | 77.00 | 88.00 | 100.00 |
| Rain (mm/hour) | 3690.00 | 0.07 | 0.27 | 0.00 | 0.00 | 0.00 | 0.00 | 6.80 |
| Atmospheric pressure (hPa) | 3690.00 | 995.83 | 7.74 | 968.20 | 991.30 | 996.60 | 1001.80 | 1011.30 |
| Cloud cover (seconds/hour) | 3690.00 | 58.67 | 38.65 | 0.00 | 19.00 | 70.00 | 98.00 | 100.00 |
| Wind speed (km/hour) | 3690.00 | 12.86 | 6.41 | 0.00 | 7.90 | 12.55 | 17.48 | 35.10 |
| Sunshine (seconds/hour) | 3690.00 | 1668.41 | 1738.40 | 0.00 | 0.00 | 499.86 | 3600.00 | 3600.00 |
Relationships affecting dissolved oxygen
DO correlations
| Correlation with DO mg/L | |
|---|---|
| Dissolved oxygen saturation (%) | 0.57 |
| Humidity (%) | -0.48 |
| pH | 0.33 |
| Sunshine (seconds/hour) | 0.32 |
| Conductivity (µS/cm) | 0.28 |
| Atmospheric pressure (hPa) | 0.21 |
| Air temperature (°C) | 0.12 |
| Wind speed (km/hour) | 0.09 |
| Ammonia/ammonium (mg/L) | 0.08 |
| Cloud cover (seconds/hour) | -0.07 |
| Rain (mm/hour) | -0.07 |
| Water temperature (°C) | -0.06 |
| Turbidity (NTU) | -0.04 |
Best lag relationships
| best_lead_hours | correlation | |
|---|---|---|
| variable | ||
| pH | 3 | 0.40 |
| Air temperature (°C) | 12 | -0.36 |
| Sunshine (seconds/hour) | 2 | 0.35 |
| Conductivity (µS/cm) | 0 | 0.28 |
| Water temperature (°C) | 8 | -0.21 |
| Cloud cover (seconds/hour) | 19 | -0.17 |
| Rain (mm/hour) | 6 | -0.16 |
| Wind speed (km/hour) | 13 | -0.16 |
| Ammonia/ammonium (mg/L) | 13 | 0.09 |
| Turbidity (NTU) | 0 | -0.04 |
Interpretation: Strong negative relationships indicate variables that rise when DO falls. In rivers, water temperature is a physical driver because warm water holds less oxygen. Ammonia/ammonium can indicate pollution and oxygen-demanding processes such as nitrification or organic decomposition. Rainfall effects can be indirect: runoff may raise turbidity and nutrients while conductivity can fall from dilution.
Time-series patterns
Diurnal effects
Hourly averages show whether readings follow a day/night rhythm. A typical river signal is oxygen rising during daylight photosynthesis and falling overnight due to respiration.
Obvious anomalies and watch-points
| variable | value | reason | |
|---|---|---|---|
| timestamp | |||
| 2026-04-21 12:00:00 | Dissolved oxygen (mg/L) | 8.41 | robust z-score 5.8 |
| 2026-04-21 12:00:00 | Dissolved oxygen saturation (%) | 109.78 | robust z-score 5.5 |
| 2026-04-21 12:00:00 | pH | 12.53 | robust z-score 4.7 |
| 2026-04-21 13:00:00 | Dissolved oxygen (mg/L) | 8.49 | robust z-score 6.9 |
| 2026-04-21 13:00:00 | Dissolved oxygen saturation (%) | 110.82 | robust z-score 6.0 |
| 2026-04-21 13:00:00 | pH | 12.49 | robust z-score 4.7 |
| 2026-04-21 14:00:00 | Dissolved oxygen (mg/L) | 8.52 | robust z-score 7.3 |
| 2026-04-21 14:00:00 | Dissolved oxygen saturation (%) | 110.26 | robust z-score 5.7 |
| 2026-04-21 14:00:00 | pH | 12.28 | robust z-score 4.2 |
| 2026-04-21 15:00:00 | Dissolved oxygen (mg/L) | 8.51 | robust z-score 7.1 |
| 2026-04-21 15:00:00 | Dissolved oxygen saturation (%) | 108.53 | robust z-score 4.9 |
| 2026-04-21 16:00:00 | Dissolved oxygen (mg/L) | 8.47 | robust z-score 6.6 |
| 2026-04-21 17:00:00 | Dissolved oxygen (mg/L) | 8.37 | robust z-score 5.3 |
| 2026-04-22 09:00:00 | pH | 12.24 | robust z-score 4.2 |
| 2026-04-22 10:00:00 | pH | 12.38 | robust z-score 4.4 |
| 2026-04-22 11:00:00 | Dissolved oxygen (mg/L) | 8.31 | robust z-score 4.5 |
| 2026-04-22 11:00:00 | Dissolved oxygen saturation (%) | 108.12 | robust z-score 4.8 |
| 2026-04-22 11:00:00 | pH | 12.49 | robust z-score 4.7 |
| 2026-04-22 12:00:00 | Dissolved oxygen (mg/L) | 8.39 | robust z-score 5.5 |
| 2026-04-22 12:00:00 | Dissolved oxygen saturation (%) | 109.94 | robust z-score 5.6 |
| 2026-04-22 12:00:00 | pH | 12.55 | robust z-score 4.8 |
| 2026-04-22 13:00:00 | Dissolved oxygen (mg/L) | 8.49 | robust z-score 6.9 |
| 2026-04-22 13:00:00 | Dissolved oxygen saturation (%) | 111.35 | robust z-score 6.2 |
| 2026-04-22 13:00:00 | pH | 12.52 | robust z-score 4.7 |
| 2026-04-22 14:00:00 | Dissolved oxygen (mg/L) | 8.54 | robust z-score 7.6 |
| 2026-04-22 14:00:00 | Dissolved oxygen saturation (%) | 110.93 | robust z-score 6.0 |
| 2026-04-22 14:00:00 | pH | 12.30 | robust z-score 4.3 |
| 2026-04-22 15:00:00 | Dissolved oxygen (mg/L) | 8.53 | robust z-score 7.4 |
| 2026-04-22 15:00:00 | Dissolved oxygen saturation (%) | 109.00 | robust z-score 5.2 |
| 2026-04-22 16:00:00 | Dissolved oxygen (mg/L) | 8.49 | robust z-score 6.9 |
| 2026-04-22 16:00:00 | Dissolved oxygen saturation (%) | 106.79 | robust z-score 4.2 |
| 2026-04-22 17:00:00 | Dissolved oxygen (mg/L) | 8.40 | robust z-score 5.7 |
| 2026-04-22 18:00:00 | Dissolved oxygen (mg/L) | 8.28 | robust z-score 4.0 |
| 2026-04-23 09:00:00 | pH | 12.37 | robust z-score 4.4 |
| 2026-04-23 10:00:00 | Dissolved oxygen (mg/L) | 8.30 | robust z-score 4.3 |
| 2026-04-23 10:00:00 | Dissolved oxygen saturation (%) | 108.36 | robust z-score 4.9 |
| 2026-04-23 10:00:00 | pH | 12.57 | robust z-score 4.8 |
| 2026-04-23 11:00:00 | Dissolved oxygen (mg/L) | 8.36 | robust z-score 5.1 |
| 2026-04-23 11:00:00 | Dissolved oxygen saturation (%) | 108.82 | robust z-score 5.1 |
| 2026-04-23 11:00:00 | pH | 12.54 | robust z-score 4.8 |
| 2026-04-23 12:00:00 | Dissolved oxygen (mg/L) | 8.43 | robust z-score 6.1 |
| 2026-04-23 12:00:00 | Dissolved oxygen saturation (%) | 110.42 | robust z-score 5.8 |
| 2026-04-23 12:00:00 | pH | 12.59 | robust z-score 4.9 |
| 2026-04-23 13:00:00 | Dissolved oxygen (mg/L) | 8.52 | robust z-score 7.3 |
| 2026-04-23 13:00:00 | Dissolved oxygen saturation (%) | 111.89 | robust z-score 6.4 |
| 2026-04-23 13:00:00 | pH | 12.57 | robust z-score 4.8 |
| 2026-04-23 14:00:00 | Dissolved oxygen (mg/L) | 8.56 | robust z-score 7.8 |
| 2026-04-23 14:00:00 | Dissolved oxygen saturation (%) | 111.58 | robust z-score 6.3 |
| 2026-04-23 14:00:00 | pH | 12.35 | robust z-score 4.4 |
| 2026-04-23 15:00:00 | Dissolved oxygen (mg/L) | 8.55 | robust z-score 7.7 |
Cause-and-effect hypotheses to test next
- Temperature → lower dissolved oxygen: expected and strongly supported by this data.
- Sunlight → photosynthesis → higher DO and pH: supported by the diurnal DO pattern and positive pH/DO relationship.
- Rainfall → runoff/dilution: rainfall can spike turbidity and nutrients while lowering conductivity through dilution.
- Ammonia/ammonium → oxygen stress risk: elevated ammonia is associated with lower DO and should be investigated around event windows.