Zic, KresimirStefan, Heinz G.2011-08-292011-08-291989-12https://hdl.handle.net/11299/114026Many lakes and reservoirs develop a seasonal temperature stratification. The thermal stratification is associated with a density stratification which effectively controls convection and diffusion in the lake. The most stable stratification conditions exist during the summer months when lakes or reservoirs exhibit large thermal gradients. Asa result the water quality of the lower layers may be reduced significantly for example because dissolved oxygen is no longer replenished by surface aeration.en-USReport