Time series of brightness temperature (TB) measurement obtained at various frequencies by the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E) are investigated to determine ice phenology parameters and ice thickness on Great Bear Lake (GBL) and Great Slave Lake (GSL), Northwest Territories, Canada. TB measurements from the 6.9, 10.7, 18.7, 23.8, 36.5, and 89.0 GHz channels (H- and V- polarization) are compared to assess their potential for detecting freeze-onset (FO)/melt-onset (MO), ice-on/ice-off dates, and ice thickness on both lakes. The sensitivity of TB measurements at 6.9, 10.7, and 18.7 GHz to ice thickness is also examined using a previously validated thermodynamic lake ice model and the most recent version of the Helsinki University of Technology (HUT) model, which accounts for the presence of a lake-ice layer under snow. This study shows that 18.7 GHz H-pol is the most suitable AMSR-E channel for detecting ice phenology events, while 18.7 GHz V-pol is preferred for estimating lake ice thickness on the two large northern lakes. These two channels therefore form the basis of new ice cover retrieval algorithms. The algorithms were applied to map monthly ice thickness products and all ice phenology parameters on GBL and GSL over seven ice seasons (2002-2009). Through application of the algorithms much was learned about the spatio-temporal dynamics of ice formation, decay and growth rate/thickness on the two lakes. Key results reveal that: 1) both FO and ice-on dates occur on average 10 days earlier on GBL than on GSL; 2) the freeze-up process or freeze duration (FO to ice-on) takes a comparable amount of time on both lakes (two to three weeks); 3) MO and ice-off dates occur on average one week and approximately four weeks later, respectively, on GBL; 4) the break-up process or melt duration (MO to ice-off) lasts for an equivalent period of time on both lakes (six to eight weeks); 5) ice cover duration is about three to four weeks longer on GBL compared to its more southern counterpart (GSL); and 6) end-of-winter ice thickness (April) on GBL tends to be on average 5-15 cm thicker than on GSL, but with both spatial variations across lakes and differences between years.

Thesis (M.A.)--University of Wisconsin, 1949. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 157-159).

Thesis (Ph.D.)--University of Western Australia, 2008.

D.Sc. (Freshwater Biology) / Please refer to full text to view abstract

Documentation of social impacts resulting from the construction of Lake Ray Roberts is to be incorporated into a two year post-impoundment study. Research objectives are to: 1) locate current residences of landowners and previous landowners who were displaced; 2) determine social impacts resulting from construction of Lake Ray Roberts; 3) document degree of satisfaction with current living conditions; 4) document landowners' degree of satisfaction associated with COE negotiations; 5) document landowners' observations. Landowners were identified by telephone and sent a mail-back questionnaire. Respondents were generally happy with current residences and communities. While courtesy and sufficient information were provided by the COE, respondents would have preferred for property settlements to be more consistent and timely.

Southeast Harney Lake Hot Spring and its effluent channel were examined for spatial and temporal variations in the concentrations of several chemical species, viz. dissolved oxygen, pH, alkalinity, phosphate-phosphorous, nitrate and nitrite-nitrogen, conductivity, chloride, flouride, temperature, calcium, magnesium, potassium, and sodium. Phosphate-phosphorous and nitrate-nitrogen both exhibited downstream increases in concentration. pH and alkalinity increased also, mainly due to CO2 evolution and temperature mediated carbon species redistribution. The diurnal pH and alkalinity curves exhibited depressions during the daylight hours due to the oxidation of ammonia to nitrate within the pool and effluent stream.

A series of four stations for sampling the waters of the Red Rivers and Lake Texoma was established. Water samples from top, middle, and bottom levels of these four stations were taken on monthly intervals during periods of homothermousity and on two-week intervals during periods of thermal stratification. These samples were analysed for the cations sodium, potassium, calcium, and magnesium, and for the anions normal carbonate, bicarbonate, sulfate, chloride, nitrate, water hardness (expressed as calcium carbonate), and phosphates. Determinations for dissolved oxygen, carbon dioxide, pH, temperature, and specific conductance were performed. Using these data, vertical profiles of the lake at these four stations were established. From the study of these data it was concluded that the waters of the Red River improve in quality coincident with impoundment, and that these improvements are sufficient to warrant the use of these waters.

No description available.

No description available.

Lake Moomaw, a 1024 ha flood control reservoir in western Virginia, retains sufficient cold, oxygenated water (< 21°C, ≥ 5.0 mg/L) to allow trout survival throughout most of the summer. However, trout habitat declines to an annual minimum in September. vertical gillnets and ultrasonic telemetry were used to determine the horizontal and vertical distribution of two cohorts of brown trout, <i>Salmo trutta</i>, and rainbow trout, <i>Oncorhynchus mykiss</i>, relative to ambient temperature and dissolved oxygen. Capture of trout in gillnets afforded the assessment of condition (K), relative liver weight (HSI), and daily consumption (CD) of age 1+ brown and rainbow trout in relation to habitat dynamics. Most age 1+ brown and rainbow trout were distributed in the metalimnion (12 - 21°C) from July to October, even when dissolved oxygen declined below 5.0 mg/L. Location in the metalimnion placed young trout near optimum temperatures and maximum prey abundance. The growth, condition, relative liver weight, and daily consumption of age 1+ brown and rainbow trout were apparently unaffected by habitat limitations. Age 1+ brown trout preyed almost exclusively on alewives, <i>Alosa pseudoharenqus</i>, whereas aquatic and terrestrial insects constituted a substantial portion of young rainbow trout diet. Age 2+ rainbow trout were distributed in the metalimnion from July to September, but were located in the hypolimnion (<12°C) in October. Adult brown trout were located in the metalimnion during July, but were distributed in the hypolimnion from August to October. Adult trout in the hypolimnion were at low temperature (10°C) and diminished dissolved oxygen concentrations (<5.0 mg/L). Distribution in the hypolimnion also resulted in isolation from primary forage alewives. Age 2+ brown trout effectively were not feeding, as only one of 16 adult brown trout collected in two years of sampling contained food. Adult rainbow trout consumed primarily alewives in August and aquatic insects in September, but were apparently not feeding in October. Small sample size precluded the direct measurement of the effects of this isolation on the growth of age 2+ trout in Lake Moomaw. A bioenergetics model predicted that even brief durations of isolation from prey could severely limit the growth of age 2+ brown and rainbow trout. / Master of Science