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LAKE DIBAWAH |
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+Lake Dibawah has a natural outlet through the River Lembong into Lake Singkarak, being thus part of one of the three lake chains in the Indonesian islands. The drainage area, which is small, is used to some extent for agriculture. Small scale fish farming is practiced at the outlet, and mollusk shells are collected from the shallow areas for various uses.
The lake was weakly stratified (RTR 34.9) and the oxygen depletion began at the depth of about 50-60 meters, while the maximum depth is 309 meters. Thus the major proportion of the lake volume is lacking oxygen. The pH was rather high, 7.7-8.5. As the lake is deep and well sheltered it is likely that mixing occurs only down to the chemocline periodically.
Total nitrogen values were from 0.180 to 0.466 mg/l N and total phosphorus values from 0.015 to 0.080 mg/l P. The highest carbon dioxide concentration was 6.5 mg/l. The chlorophyll a concentration varied from 1.16 to 1.64 mg/m3, algal biomass was 0.18 mg/l and transparency 2.5 meters. The dominant algae in March 1992 were coca green algae, like genus Coenochloris, and in August 1993 the dominant genus was conjugatophyte Spirogyra sp., and chlorophytes Didymocystis bicellularis and Oocystis cf. solitaria were abundant. The lake is oligotrophic and its state is good.
From
the littoral areas mollusk shells are collected for chicken feed. The outlet
is also used for fish culturing in the wooden latch cages.
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