ABSTRACT:
The viability of the agriculture industry depends on the private landowner having a working knowledge of watershed functions in order to make environmental management a part of their operational plans. A three-year study was designed to capture the temperature signature and substrate sediments of individual stream segments. The daily pattern of temperature change (4 hr. periods between 5 am and 5 pm) in both air and water were examined based on elevation and were classified as cold, cool, and warm stream segments. Thermal gradients and heating rates at the study sites were different when compared by elevation. Data compared across elevation showed cold water sites had the greatest temperature changes occurring between 1 and 5 pm and cool and warm water sites changed most between 9 am and 1 pm. Adiabatic stratification of the watershed environment has an influence on the thermal pattern of stream temperature and should be considered when assessing daily maximum water temperatures. Channel substrate measurement of “fines” was between 0.03% and 4% in 2000 and no substrate sediments were found in quantities greater than 20%. Overall, thermal and sediment pollution were undetected once natural and/or background conditions were established.
Footnotes
Pat A. Larson is a forester and Larry L Larson is a range ecologist in La Grande, Oregon.
- Copyright 2003 by the Soil and Water Conservation Society
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.