Annual Temperature Study of Five Northwest Arkansas Lakes

Transcription

1 Journal of the Arkansas Academy of Science Volume 8 Article Annual Temperature Study of Five Northwest Arkansas Lakes Carl E. Hoffman Andrew H. Hulsey Charles Nelson Bobby Owen Buford Tatum Follow this and additional works at: Part of the Fresh Water Studies Commons Recommended Citation Hoffman, Carl E.; Hulsey, Andrew H.; Nelson, Charles; Owen, Bobby; and Tatum, Buford (1955) "Annual Temperature Study of Five Northwest Arkansas Lakes," Journal of the Arkansas Academy of Science: Vol. 8, Article 10. Available at: This article is available for use under the Creative Commons license: Attribution-NoDerivatives 4.0 International (CC BY-ND 4.0). Users are able to read, download, copy, prt, distribute, search, lk to the full texts of these articles, or use them for any other lawful purpose, without askg prior permission from the publisher or the author. This Article is brought to you for free and open access by ScholarWorks@UARK. It has been accepted for clusion Journal of the Arkansas Academy of Science by an authorized editor of ScholarWorks@UARK. For more formation, please contact scholar@uark.edu, ccmiddle@uark.edu.

2 AN ANNUAL TEMPERATURE STUDY OF FIVE NORTHWEST ARKANSAS LAKES CARL E. HOFFMAN, ANDREW HULSEY, CHARLES NELSON, BOBBY OWEN and BUFORD TATUM University of Arkansas Temperature records taken over a period of fifteen years from lakes northwestern Arkansas show that lakes this region normally differ from typically stratified lakes of the temperate zone that they do not go through a wter stagnation period. Between the years 1938 ai.d 1953 only one stance of freezg over was found; 1940 the lakes of this region were covered with a th coatg of ice durg the first week January. In recent years a number of vestigators have published reports on thermal conditions for lakes southwestern United States. Some of these publications are: Harris and Silvey (1940) and Cheatum, Longnecker, and Metier (1942) for Texas; Moore (1950) for Louisiana; Irw (1941) and Wallen (1951) for Oklahoma; and Hoffman (1951,1952) for Arkansas. Ail of these vestigators report thermal stratification summer; and those which dealt with annual temperature studies show one contuous circulation period throughout the wter. Durg the years 1949 and 1950 vertical series of temperatures were taken, usg a Negretti and Zambra reversg thermometer, from five artificial lakes northwestern Arkansas. These temperature records are presented here so that they may be compared with published accounts taken from lakes neighborg states and from other areas. The five lakes studied ranged depth from 5 to 20 meters, area from 50 to acres, and were located with a radius of 40 miles of Fayetteville, Arkansas (Table 1). Table 1. General Data for Lakes. Maximum Surface area Exposure to Lake Impounded Depth wd meters acres action Fort Smith Moderate Wedgton Moderate Atalanta Slight Fayetteville Great Hdsville Slight STRATIFICATION PERIOD Vertical series of temperature readgs taken from five Northwest Arkansas lakes between July 1949 and June 1950 are presented Table 2. In this table the extent of the termocle is dicated by numerals italics, and a sudden drop temperature between two adjacent meter levels is dicated by an underscore. Birge' s rule, i.e., a temperature drop of1.0 C or more per meter (Welch, 1952), was used to select the thermocle limits. Table 2 shows that the five lakes were already stratified July, 1949, when this vestigation was begun, and all but two remaed this thermal state through October. Two lakes, Atal an ta and Fayetteville, had no thermocles October, but a temperature gradient existed between the surface and the bottom levels. Chemical records taken durg this time, but not presented this paper, dicate that even though no thermocles were present Lakes Atalanta and Kayetteville durg October 1949, chemical stagnation conditions still prevailed at the lower levels. In the sprg of 1950 all lakes showed stratification by the first week May. The temperature of the water near the bottom when stratification was first recorded ranged from 10.8 C to 12,0 C. No defite stratification pattern was found as to thickness and position of thermocles between sprg and middle Published by Arkansas Academy of Science, 1955 L44 144

3 Table 2. Vertical series of temperature readgs for five Northwest Arkansas lakes from July, 1949 to June, LAKE ATALANTA, BENTON COUNTY, ARKANSAS Depth Dates of Sampl g 7/5 7/21 8/1 8/14 9/24 10/9 10/24 11/7 11/26 12/12 1/6 2/17 3/2 3/29 4/10 4/24 5/8 5/23 6/ ^4 22J jO ' * J Ik * M Depth LAKE WEDINGTON, WASHINGTON COUNTY, ARKANSAS Dates of Samplg 7/24 8/2 8/16 9/25 10/9 10/23 11/6 11/27 12/18 1/12 2/21 3/17 4/1 4/13 5/4 6/ C ^ ^

4 LAKE HINDSVILLE,MADISON COUNTY, ARKANSAS Depth Dates of Sampl g 7/13 8/U 9/28 10/16 10/31 11/10 12/11 2/23 3/15 3/30 4/12 4/30 5/17 5/30 6/ JL <M Depth LAKE FAYETTEVILLE, WASHINGTON COUNTY, ARKANSAS Dates of Sampl g 7/7 7/26 8/7 8/14 9/26 10/12 10/ M/28 12/14 l/ll 2/23 3/17 4/9 4/23 5/7 5/24 6/ J? L i * 19. U J> * U Published by Arkansas Academy of Science,

5 Depth LAKE FORT SMITH, CRAWFORD COUNTY, ARKANSAS Dates of Samp] g 7/12 7/19 8/9 9/23 10/7 10/22 I1/4 I1/25 12/9 1/6 2/2* 3/1 1 t/l 4/20 5/5 5/19 6/ U OJ J) ^ * Less than l.o't per meter ** 15 - meter depth station Numerals italics Limits of thermocle Underscore :Drop temperature between adjacent meters 147

6 148 ARKANSAS Journal of the Arkansas Academy of Science, Vol. 8 [1955], Art. 10 ACADEMY OF SCIENCE summer. However, records for 1949 (Table 2) dicate that the thermocles became thner and their upper limits deeper between late summer and the end of the stratification period autumn. A phenomenon often encountered this study was a sudden drop temperature between two adjacent horizontal meter levels. In some stances this condition was found above the thermocle (Lake Atalanta July and August), below the thermocle (Lake Fort Smith on August 9, 1949), or place of a thermocle (Lake Fort Smith on November 4, 1949 and Lake Atalantaon April 24, 1950). Secondary thermocles (at least one meter thickness) were preeent Lake Fayetteville on July 26, 1949, and Lake Fort Smith on August 9, CIRCULATION PERIOD Table 2 shows that, with a few exceptions, the lakes were unstratified from November to April. In two stances, thermal stratification occurred durg the wter the two lakes with the greatest wd protection; Lake Atalanta stratified on March 2, 1950, and Lake Hdsville on February 23, In general, the vertical temperatures durg this time were either homothermal or had such a slight gradient that a small amount of wd was able to itiate circulation. Because it is possible for the lake to overturn at any time from November to April it is here considered as the circulation period. Chemical records taken from November to April show that dissolved oxygen, carbon dioxide, and ph readgs were nearly uniform from surface to bottom on each samplg date. This would seem to dicate that the temporary thermal stratifications that appear durg this time are not of sufficient duration to allow a chemical differentiation between levels. REFERENCES 1. Cheatum, E. P., Longnecker, Mayne, and Metier, Alv., " Limnological Observations on an East Texas Lake." Trans. Amer. Micro. Soc, 61, pp (1942). 2. Harris, Benjam and Silvey, J. K. Gwynn, "Limnological Investigation on Texas Reservoir Lakes." Scol. Monographs, 10, pp (1949). 3. Hoffman, Carl E., 'Limnological Studies Arkansas. Temperature and Turbidity Records for Lake Fort Smith." Ark. Acad. Sci., 4, pp (1951). 4. Hoffman, Carl E.,and Causey, David, "Limnological Studies Arkansas. I. Physico-chemical and Net Plankton Studies of Lake Fort Smith its Fourth Year of Impoundment. " Ark. Acad. Sci., 5, pp (1952). 5. Irw, W. H., "Prelimary Records of Physico-chemical Features of Grand Lake, Oklahoma." Proc. Oklahoma Acad. Sci., 22, pp (1941). 6. Moore, Walter G.,"Limnological Studies of Louisiana Lakes." I.Lake Providence." Ecology, 31, pp (1950). 7. Wallen, I. E., "Thermal Stratification Some Eastern Oklahoma Waters. Proc. Oklahoma Acad. Sci., 31, pp (1951). 8. Welch, P. S., Limnology. McGrawHill, New York (1952). 1 Published by Arkansas Academy of Science,