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LAKE BURE- NETLAKE SITE IN DENMARK
Website: www.netlake.org Eleanor Jennings [email protected] Local contacts: Aarhus University - Department of Bioscience - Marine Ecology Peter Anton Stæhr: [email protected] http://pure.au.dk/portal/en/[email protected] University of Copenhagen - freshwater Biological Laboratory Mikkel René Andersen [email protected]
Contacts Monitoring buoy and platform
Sensors
NETworking Lake observatories in Europe: COST Action ES 1201
The NETLAKE COST Action aims to build a network of sites and individuals to support the development and deployment of sensor-based systems in lakes and reservoirs and promote their use to address current and future water quality issues.
Aim of NETLAKE
Lake Bure :
The lake is situated in a glacial valley, carved out by melt water under the ice cover, during the last ice-age, figure 1. The lake is mesotrophic-eutrophic, and water transparency during summer is typically over 3,5 meters. The catchment area is dominated by forest (38%), agriculture (27%) and urban areas (23%).
Figure 1. Location of the Danish netlake site and the buoy and its location within Lake Bure.
The buoy is equipped with a winch, which lowers a Y S I Environmental 6600 v2. multisonde through the water column, measuring every half meter down to 10 meters. In this way the entire water column is measured twice each hour. The multisonde measures dissolved oxygen, temperature, pH level, conductivity and fluorescence. The buoy is also equipped with a self-cleaning rack of light sensors. A series of 4 light sensors measures light attenuation in the surface waters. Furthermore the buoy features a meteorological station which records PAR light and wind speed. See youtube video of buoy here: http://www.youtube.com/watch?v=TgFhACVANBs
U N I V E R S I T Y O F
C O P E N H A G E N
Area: 76,1 ha Avg. depth: 6,7 m Max depth: 10,8 m Volume: 5.100.000 m3
Height above sea-level: 26 m Water residence time: 11,2 years Catchment area: 260 ha
Lake info :
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Temperature (oC)
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The winch system, which is connected to the YSI multisonde, features a cellular modem which transmits data to a server, this allows online access. The meteorological station, as well as underwater light sensors, records data internally and the data is retrieved biweekly when the multisonde receives maintenance and additional water samples are collected. Preliminary data, figure 2, shows good oxygen availability throughout the year, however in summer the lake stratifies and oxygen is depleted in the hypolimnion. Chlorophyll a concentrations are highest during the spring bloom and in early autumn following the summer stratification.
Data available
Figure 2. Data from Lake Bure, April to October 2012.
