Temperature

There is great importance to the water temperature of a river. Temperature directly affects many of the physical, biological, and chemical characteristics of a river
Most aquatic organisms have adapted to survive within a certain range of water temperatures. Not many organisms can take extremes of heat or cold.

Testing for Temperature

Lower the thermometer four inches below the water surface at the site. Keep the thermometer there until a constant reading is obtained.

Temperature Levels and What They Mean

The amount of oxygen that can be dissolved in water is influenced by temperature. Cold water holds more oxygen than warm water. The more oxygen in the water, the more living things it can support. A tolerable range for temperature is 0°C-36°C. Temperature also influences the rate of photosynthesis by algae and larger aquatic plants. As water temperature rises, the rate of photosynthesis by algae and larger aquatic plants increases.

Results

The results of the temperature found in the North Channel of the Chicago River are listed below:

Site	Temperature
1	9°C
2	10°C
3	11°C

These temperatures are well fall well between the tolerable range of temperature for organisms. Therefore, the temperature contributes positively towards water quality.

Influences

Humans can cause harm to a river by thermal pollution. That is when you add warm water to a river and it increases water temperature. Sometimes, nuclear power plants release water used to cool machinery, which can cause thermal pollution. It may also happen from storm water running off warm urban surfaces, such as streets, sidewalks and parking lots.
Cutting down trees can also affect water temperature. Trees help shade a river. When water is not shaded and exposed to direct sunlight it can be as much as 20°F warmer. Soil erosion also increases from cutting trees, which is yet another factor that contributes to the warmth of water temperature.