Аннотация:Snail Lake, located in Minnesota, USA, is a small lake (190 acres) with watershed area
of 987 acres and maximum depth of about 30 feet. The lake has been known to have a
steadily dropping water level, and in 1993 the new augmentation system was introduced,
with water from Sucker Lake pumping into the Snail Lake. In 2007 pumping was stopped
due to an invasive mussel species threat, and restarted in the end of 2009. In years 2011
and 2013–2016 no water was pumped as water level was maintained by precipitation.
One-dimensional General Lake Model was used to simulate Snail Lake’s vertical thermal
structure and mixing regime over the period of 2005–2016. With water temperature and
specific conductance vertical distribution data from Minnesota Pollution Control Agency
and EPA National Aquatic Resources Survey the model was calibrated and validated to
create better compliance with real conditions. Information on water pumping rates was
provided by City of Shoreview Engineering Department. Patterns in forming of lake
stratification were defined for periods with active lake augmentation and periods with no
pumping. Differences in lake water temperature and mixing regime associated with
different pumping schedules and weather conditions are described. Lake Analyzer tool
was used to calculate key mixing indices for different conditions. With lake mixing and
stratification being key factors of all temperate water ecosystems functioning, results of
this research can be used in connection with biogeochemical studies to gain further
knowledge of Snail Lake ecology.