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Full-Text Articles in Earth Sciences
Water Quality In Southeastern Minnesota Streams: Observations Along A Gradient Of Land Use And Geology, Nels H. Troelstrup Jr., James A. Perry
Water Quality In Southeastern Minnesota Streams: Observations Along A Gradient Of Land Use And Geology, Nels H. Troelstrup Jr., James A. Perry
Journal of the Minnesota Academy of Science
ABSTRACT-Surface water quality in southeastern Minnesota's driftless area exhibits subregional and local spatial patterns which are highly correlated with subsurface geology and land-use practices. Some variables appear to respond on subregional or watershed scales. Nitrate, specific conductance, alkalinity, and surface water atrazine concentrations were lower in streams originating from the Prairie Du Chien or Jordan sandstone ~quifers of easte:n Fillmore and Houston Counties than those originating from the Galena limestone aquifer m west-central Fillmore County. In addition, the numbers of pollution intolerant and functionally specialized invertebrates in the benthic community were higher in the eastern streams. Gross primary production on …
Lake Mixing Dynamics And Water Quality Models, Heinz G. Stefan
Lake Mixing Dynamics And Water Quality Models, Heinz G. Stefan
Journal of the Minnesota Academy of Science
ABSTRACT-To forecast water quality changes or to evaluate the potential success of restoration measures in lakes, it is necessary to formulate "models" which relate lake water quality to the inflows and outflows of materials and energy. Concepts of dynamic deterministic (cause-effect) models and examples are presented. The relationship between internal thermo-hydraulic processes and water quality is stressed. Stratification mixing, and nutrient kinetics are included in these models.
The Regional Nature Of Lake Water Quality Across Minnesota: An Analysis For Improving Resource Management, Steven A. Heiskary, C. Bruce Wilson
The Regional Nature Of Lake Water Quality Across Minnesota: An Analysis For Improving Resource Management, Steven A. Heiskary, C. Bruce Wilson
Journal of the Minnesota Academy of Science
ABSTRACT-The diversity and number of lakes in Minnesota may be better understood by the use of regional characterizations of lake and watershed information. Recent efforts have utilized the ecoregion approach to define seven regions across Minnesota, four of which contain 98 percent of our lake resources. Typical land use patterns vary regionally as do lake water quality patterns. Understanding these patterns will assist lake managers to develop realistic goals and minimize false expectations. Regional assessments facilitate the definition of reasonable goals, expressed in terms of: average summer nutrient concentrations, probability of nuisance conditions ( e.g., estimates of algal bloom frequency), …