Stauraumverlandung und Kolkabwehr

Några iakttagelser över vittring, erosion och slambildning i Malaya och Australien

“…Enir savidl kalla som tempererade arstider saknas, blir skillnaden i medeltemperaturen mellan arets kallaste och dess varmaste minad liten och uppgir ofta ej till mer din 50 C.1 Vittringen i Malaya kan alltsa fortgA med stor intensitet under hela aret. 1 Motsvarande temperaturskillnad utg6r i Malm6 16i0 C och i Karesuando 28? C. F6r att unders6ka inverkan av den intensiva solstrilningen pi bergets temperatur m~tte f6rf.…”

Fluvial morphology in terms of slope, abrasion, and bed‐load

“…Sternberg abrasion-law--As the particles of bed-load move downstream, their size is reduced by abrasion, collision, and solution [5,6]. The most important of these is abrasion, for which Sternberg developed a theoretical law that has been verified experimentally by Schoklitsch [5» 6, 7].…”

“…Values of the coefficient of abrasion for various rocks will be found in [5], [6], and [7], Unfortunately, V is not a constant for a given rock. It increases with the one-fourth power of the velocity of the particle and Is proportional to the diameter of the underlying material [5, p. 351].…”

Jet scour

“…Underflow has a considerable potential for scour caused by either high flow velocities or high turbulence intensities. Following Schoklitsch (1935Schoklitsch ( , 1962 it is possible to distinguish attached jets (or wave or plunging jumps) and surface jets (or moving or inverted jumps) in which the jet form depends on a number of factors such as submergence, flow and turbulence patterns.…”

“…in which b u is the width of the 2D jet, U e is the mean efflux velocity, x is the horizontal distance from the 2D outlet and  1 (= 0.2) and  2 (= 0.5) are coefficients (Schoklitsch 1935) Jets, which are initiated by a propeller, accelerate flow in axial, radial and tangential directions. The flow behind a ship's propeller is comparable to a flow in a free (or 3D) jet, because in both flows the jet diffuses.…”