page 20 of the UWP Educator’s Guide to Teaching Students About the Upper Uncompahgre River Watershed (also see contents, introduction & pdf link)
Stream Temperature: What is it?
Water temperature is an important physical property of every river and stream. Many plants, animals, and other organisms living in streams can flourish only in a specific range of water temperatures. Temperature can affect certain aspects of water quality.
Why Does it Matter?
Water temperature is an important physical property of every river and stream. Many plants, animals, and other organisms living in streams can flourish only in a specific range of water temperatures. Temperature can affect certain aspects of water quality. For example, higher temperatures reduce levels of dissolved oxygen in the water, which can negatively affect the growth and productivity of aquatic life. Persistently warmer temperatures in streams can accelerate natural chemical reactions and release excess nutrients into the water.
A stream’s water temperature can also influence the circulation or mixing patterns in the water it flows into, like reservoirs, potentially affecting nutrient levels and salinity. Temperatures can vary naturally along the length of a stream, from cold temperatures near a source of meltwater to higher temperatures near its outlet to a lake. The temperature at any given point is a product of many different factors, including sources of water (for example, melted snow, a recent rainstorm, or groundwater), the amount of water in the stream (streamflow), air temperature, plants along the bank (for example, trees that provide shade), and the amount of development within the watershed. Over time, however, an area’s climate has the strongest natural influence on a stream’s temperature.
How is it Measured?
Teachers: Students will work in pairs and log stream temperature using a Celsius thermometer they pass from group to group.
The thermometer should be left in the water for approximately 2 minutes, three feet into the stream (long florescent flagging is attached to the thermometer).
Source: https://datastream.org/en-ca/guidebook/conductivity and https://datastream.org/en-ca/guidebook/temperature
