التفاصيل البيبلوغرافية
| العنوان: |
Novel dimensionless index for physically based assessment of thermal refugia characterizes off‐channel habitat on gravel bed river. |
| المؤلفون: |
Gombert, Carolyn E., Lancaster, Stephen T., Grant, Gordon E., Flitcroft, Rebecca L. |
| المصدر: |
Journal of the American Water Resources Association; Aug2023, Vol. 59 Issue 4, p615-634, 20p |
| مصطلحات موضوعية: |
RIVER channels, WATER temperature, RICHARDSON number, GRAVEL, SOLAR radiation, HEAT flux |
| مستخلص: |
In the Willamette River, OR, main channel temperatures can be too warm for cold water fishes, causing fish to concentrate in secondary channel features that provide thermal refugia. However, temperature regimes vary among and within features. Improved understanding of physical processes controlling thermal regimes is needed. This study developed a dimensionless index for assessment of thermal refugia on the upper Willamette River. The novel hyporheic insolation (HIN) index uses minimal field measurements to predict thermal refugia resulting from buffering. Continuous water temperature measurements at one side channel, eight alcoves, and six beaver ponds provided data to ground truth calculated ℍin predictions. Water temperature records were first used to characterize stratification at sites. Calculation of the Richardson number, an index of stability, showed two well‐mixed sites and 13 stratified sites. At stratified sites, calculated ℍin values characterized the ratio of cooling flux from hyporheic discharge to heat flux from incoming solar radiation. As ℍin increased, measured temperatures at sites decreased. Despite overall scatter, a logarithmic fit to bin‐averaged ℍin values showed R2 = 0.91. Calculations suggest that secondary channel features characterized by stratification and cool hyporheic discharge can provide thermal refugia. Accordingly, the HIN index may serve as a practical tool grounded in physical processes governing temperature across a floodplain. [ABSTRACT FROM AUTHOR] |
|
Copyright of Journal of the American Water Resources Association is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
| قاعدة البيانات: |
Complementary Index |