The physical parameters of water quality can be broken down into many topics such as turbidity and taste or odor to name a few. But one needs to also take into consideration the nature of the physical parameters of the ecosystem surrounding a water source to also understand the physical appearance of a later finished water. One of the best barometers of a water is its actual temperature in its natural ecosystem. Temperature affects sediment and microbrial growth among other source water characteristics. What are the variables that affect a waterway's temperature?
The color of the water. Most heat warming surface waters comes from the sun, so waterways with dark-colored water, or those with dark muddy bottoms, absorb heat best.
The depth of the water. Deep waters usually are colder than shallow waters simply because they require more time to warm up.
The amount of shade received from shoreline vegetation. Trees overhanging a lake shore or river bank shade the water from sunlight. Some narrow creeks and streams are almost completely covered with overhanging vegetation during certain times of the year. The shade prevents water temperatures from rising too fast on bright sunny days.
The latitude of the waterway. Lakes and rivers in cold climates are naturally colder than those in warm climates.
The time of year. The temperature of waterways varies with the seasons.
The temperature of the water supplying the waterways. Some lakes and rivers are fed by cold mountain streams or underground springs. Others are supplied by rain and/or surface run-off. The temperature of the water flowing into a lake, river or stream helps determine its temperature.
The volume of the water. the more water there is, the longer it takes to heat up or cool down.
The temperature of effluents dumped into the water. When people dump heated effluents into waterways, the effluents raise the temperature of the water. Fish and most aquatic organisms are cold-blooded.