Bibliography Background About KRIS

Quotes regarding water temperature

The following is an excerpt from Poole and Berman (1999): Pathways of Human Influence on Water Temperature Dynamics in Stream Channels.

" Stream characteristics that influence the rate of  heat exchange with the atmosphere can be said to insulate the stream. These characteristics include the height, density, and proximity to the channel of riparian vegetation and the width of the stream channel. Riparian vegetation shades the stream, blocking solar radiation from reaching the channel and reducing the heat load to the stream (Hostetler 1991, Naiman and others 1992, Davies and Nelson 1994, Li and others 1994). Vegetation also reduces wind speed across the stream channel thereby trapping air against the water surface. This action reduces conductive heat exchange with the atmosphere by decreasing convection and advection of heat energy to the water surface (Naiman and others 1992). Width influences channel surface area across which heat is exchanged; a greater surface area allows for more rapid conductive heat transfer. Under the same climatic conditions, narrower, deeper channels will not exchange heat with the atmosphere as rapidly as shallow, wide channels. Similarly, riparian vegetation of a given height will shade a larger percentage of a narrow channel than a wide channel."


The following is an excerpt from the introduction to Essig (1998): The Dilemma of Applying Uniform Temperature Criteria in a Diverse Environment: An Issue Analysis 

"Bartholow (1989) describes the physical factors affecting stream temperatures as used in the Instream Water Temperature Model (SNTEMP) (Theurer and others 1984), and reports the results of a sensitivity analysis of the SNTEMP. When predicting mean daily water temperature, air temperature is the most sensitive input variable. Relative humidity is the next most sensitive input variable, accounting for less than half as much change in stream temperature. Percent shade follows a close third to relative humidity. When predicting maximum daily water temperature, air temperature is just as important, but percent shade, which affects diurnal range, overtakes relative humidity as the second most sensitive variable. For both measures, stream flow is the fourth most sensitive variable and 'water temperature is very sensitive to changes in air temperature when stream flow is low'."