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Parameters Measured

Surface Water Temperature

Water temperature at real time surface water quality monitoring stations is measured in degrees Celsius (°C).

The temperature of water is an important factor in an aquatic ecosystem because it controls biological activities and chemical processes. Stream systems exhibit diel (daily) temperature variations. Most aquatic organisms depend upon the environment to regulate metabolic rates and have adapted to temperature ranges that occur in their habitat. However, alteration of habitat, especially by human activities, can cause temperatures to exceed these ranges.

Removal of riparian (riverside) vegetation decreases shading and may allow water temperatures to exceed the typical range (as well as destroy microhabitat) due to increased exposure to solar radiation. Increased solar radiation warms water causing metabolic processes to break down.

Runoff from previously natural, undeveloped areas which are now covered by impermeable surfaces (buildings and pavement) may enter a stream system through storm drains at velocities that can scour and widen a stream channel. Water flowing in wide, shallow streams tends to warm up more quickly than water flowing in natural deep, narrow channels, especially during hot, dry seasons when water volume is low.

Temperature also affects the amount of dissolved oxygen that is available to aquatic organisms. As a general rule, cool water is capable of retaining more dissolved oxygen than warm water. As water temperatures increase, metabolic activities such as respiration also increase, but less dissolved oxygen is available for consumption. Industrial discharges and wastewater outflows may also release warm water into a stream system increasing the oxygen demand of organisms due to increased metabolic activities. In addition, the affect of oxygen demanding wastes on the aquatic environment is enhanced by warm water temperatures.