Design
The LakeLab in Lake Stechlin consists of a large central enclosure (30 metres in diameter) and 24 enclosures of 9 metres diameter that serve as the experimental units. Their walls are made of special plastic sheets fastened to a floating aluminium ring and stabilized by a supporting underwater structure. To the bottom, the sheets reach down into the sediment of the lake. The enclosures are held together by steel cables and are surrounded by a floating circular walkway. The entire setup is anchored to the lake ground, preventing the LakeLab from drifting.
Inside the enclosures, instruments continuously deliver data from various water depths, which are transmitted to a computer and stored in a database. This produces records of the water temperature, oxygen content and light conditions, for example.
Using a sprinkler system to recirculate the water, the researchers can actively
modify the environment inside the enclosures. Thus, it is possible for example,
to experimentally increase the depth of the warm surface water layer or the
temperature of the deep water as well as to destroy the thermocline during
summer stratification simulating a heavy summer storm. These conditions are
expected to occur in Lake Stechlin over the next few years or decades as a
result of climate change.
Design data
Dimensions:
- 1 central cylinder, diameter 30 m, water volume approx. 14,000 m3
- 24 enclosures as experimental units, diameter 9 m, water volume approx. 1,200 m3
Supporting structure:
- Aluminium for the floating ring and the supporting structure under water
Sheet material:
-
Stamoid insulating fabric 4800 ISO between 0–11 m depth
-
Stamoid fabric 1250 ISO between 11–20 m depth and into the sediment
-
Integrated zip system for opening the sheets under water for controlled water exchange
- Fully surrounding walkway
- Instrument mounts for sediment traps and measuring probes lowerable by electric winches
- Height-adjustable water recirculation system with perforated floating ring, rising conduit and pump
- One industrial computer per experimental unit for controlling the electric winches and for recording and forwarding the measured data
Companies involved
System construction: Ago Hydroair, Berlin
Profiler system: ISW-Wassermesstechnik, Fünfseen
Measuring probes: Ecotech, Bonn; bbe-moldaenke, Kronshagen