琵琶湖南湖の湖流観測(2)-吹送流の時間的変化-

Abstract

At the fixed station in Lake Biwa, 123 profiles of the current, wind, air and watertemperatures were measured in every 10-20 minutes within the two periods. Magnitude ofthe wind-driven current is largely affected by stability condition; steeper gradients andlarger deflections of surface current were observed in stable stratification due to radiation.The former is found to be well described by the shear function used in meteorology. Theroughness decreases as wind increases, and smooth conditions are to be proved. Thecurrent consists of the viscous sublayer, log-linear and bottom regions. Extending theeffective viscosity to the hydraulically rough conditions with use of the analogy betweenthe shear function and the effective viscosity, a resistance law is derived from that for pipeflows.