Geothermal influences on the limnology of Lake Rotoiti: preliminary conclusions from the 1982 field data
By: Spigel, R.H.
Contributor(s): Timperley, M.H. (DSIR, Division of Marine and Freshwater Science, Taupo Research Laboratory. Taupo).Material type: BookSeries: Taupo Research Laboratory report: no. 58Publisher: Taupo, N.Z. : Taupo Research Laboratory, 1983Description: 18 leaves : illustrations (figures) ; 30 cm.Subject(s): LAKE ROTOITI (ROTORUA DISTRICT) | LIMNOLOGY | NZMS260V15 | GEOTHERMAL DISCHARGES | HYPOLIMNION | HEAT FLUX | THERMAL CONDUCTIVITY | THERMAL ANALYSIS | WATER CIRCULATION | WATER MIXING | WATER TEMPERATURE | TURBIDITY | WATER CHEMISTRY | TEMPERATURE DISTRIBUTION | FRESHWATER ECOLOGY | NUTRIENT CYCLES | SEASONAL VARIATIONS | AMMONIA | NITRIFICATION | LAKE SEDIMENTS
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|JOURNAL||WELLINGTON STACK||STACK NO. 58 1983||1||Available||J016618|
5 refs; 4 figs; unpublished file report 27/T/58
This report presents a summary of work to date on the investigation of geothermal influence on the limnology of Lake Rotoiti (North Island). Interpretation of the physical processes associated with heating, mixing, and stratification can now be made with some confidence. A computer model which utilizes lake bathymetric data as well as observed daily meteorological data for solar radiation, air temperature, humidity, wind speed, rainfall, and streamflow for the period September 1981 - July 1982 has been applied to the lake. The model accounts for the dominant physical processes which control thermal stratification and mixing, and has been used to predict the consequences to the lakes' thermal regime of increased bottom heat inputs under 1981-1982 meteorological conditions. Interpretation of the chemical and biological processes is much more difficult, however. Some of the mechanisms by which the geothermal input influences lake ecology have been tentatively identified. These mechanisms are yet understood in only a qualitative way, and we are still working to clarify the relative importance of these mechanisms. The influence of Lake Rotorua inflows further obscures attempts to link lake limnology directly with geothermal inflows. As a result of these difficulties it may prove to be practically impossible to predict the long term consequences of the heat input, or changes in heat input, on the limnology of Lake Rotoiti. (auth/EIM)