form and extent of natural pollutant sources are needed to formulate meaningful water quality management programs.”
Stream temperature is dependent on heat transfer with substances it contacts and incoming solar radiation. Clean water absorbs or transmits most of the visible spectrum as well as the far infrared. If energy is absorbed, it is converted to heat. If transmitted, it is absorbed by underlying soil and absorbed as heat energy.
The most significant factor in stream temperature influenced by livestock management is stream morphology. Narrow, deep streams have less surface area to gain heat from the air than shallow, wide streams. Shallow, wide streams also allow more solar radiation to be absorbed by the streambed, which immediately transmits this to the water through convection. Proper grazing maintains healthy roots of both herbaceous and woody vegetation and prevents trampling, protecting stream function and the mechanisms which moderate temperature.
Riparian forest vegetation intercepts light and reduces incoming solar radiation and contributes to proper stream form.
Management to improve or maintain water quality needs to incorporate practices that reduce the likelihood of direct deposition and discourage overland flow or manure, or conversely, encourage as much precipitation as possible to enter the soil.
Water tanks – Water tanks are an extremely valuable management tool. Miner, Buckhouse, and Moore (1992) found that the presence of a watering tank reduced the time that livestock spent drinking or loafing in the stream by more than 90%. Logically, there is a corresponding decrease in direct deposition of manure into that stream. Where animals are dispersed, i.e., not concentrated on or near the stream, there is little documentable effect on a stream’s chemical composition or bacterial loading (Milne 1976).