Thermal and hydraulic characteristics of a geothermally influenced trout stream, the Firehole River of Yellowstone National Park / by Dalton Earl Burkhalter.

"This is an authorized facsimile printed by microfilm/xerography on acid-free paper in 1982 by UNIVERSITY MICROFILMS INTERNATIONAL, Ann Arbor, Michigan, U.S.A., London, England."

Thesis (Ph.D.) - Montana State University, 1979

Includes bibliographical references (pages 83-87).

Vita -- Acknowledgement -- List of Tables -- List of Figures -- Abstract -- Introduction -- Description of Study Area -- Methods -- Results -- Discharge -- Temperature -- Infrared imagery -- Heat rate from geothermal inflows -- Solar insolation -- Discussion -- Appendix -- References Cited.

The Firehole River in Yellowstone National Park, Wyoming, is thermally enriched by the effluents of three geyser basins and numerous other geothermal features. During summer months temperatures in the lower reaches frequently exceed levels considered lethal for trout, however, self-propagating populations of brown and rainbow trout exist there year-round. Hydraulic and thermal characteristics of this stream were measured from July, 1974, to September, 1977, as part of a broader study of the thermal environment and biology of these resident trout populations. The river discharge averaged 2.1 and 7.5 m3/s, respectively, at stations separated by 18.5 km above and below the bulk of the thermal inflow. About 1.5-2.5 m3/s was estimated to enter the Firehole from geothermal features in the study reach, representing approximately 20-40% of total discharge during non-runoff periods. The upper (unheated) station mean temperature ranged from 2.0 to 14.5 C, while the lower (heated) station mean ranged from 12.0 to 26.0 C. The lower station averaged about 11 C higher than the upper station. The highest temperature recorded at the lower station was 29.5 C and although this exceeds the upper lethal limit for trout, no fish kills were observed. The power added to the river between the upper and lower stations by geothermal features was estimated as 425 MW. Average monthly solar insolation on a horizontal surface from sun and sky during critical summer months ranged from 5.2 to 7.2 kW-h/m2-day averaging about 78% of possible clear-sky insolation. The thermal loading from solar insolation on the river surface between upper and lower stations was estimated in the annual range 26-108 MW. Thermal infrared (IR) imagery was utilized to thermally map the river throughout the reaches where thermal inflows occur. The IR imagery identified five areas in the river where significant thermal gradients occur, some of which very probably influence fish movements.

GRETA POINT: 551.23(738.7) BUR