Further Development of the Calculation of Water Level Curves in Irregular Channels.

The author has introduced a new relationship for the calculation of the water level curves of steady, gradually changing waterflows. In his method the non-prismatic feature and the longitudinal distribution of the discharge had been more distinctly taken into account than earlier through changes considered in velocity-height. Accuracy of the method was proved indirectly because of lack of measurements. For a stretch of the Danube - between river kilometers of 1816 and 1842 - points characterizing the water level curve were calculated by the traditionally Bernoulli-equation (Z//B) and according to the relationship denoted as (Z//D). The differences DELTA Z equals Z//D minus Z//B are presented and the wetted cross-sections (A) belonging to levels Z//D. As a result, it could be concluded that the water levels were always higher than those calculated by the Bernoulli-equation if the bottom-threshold or the surface were decreasing and vice versa.