Discussion of construction norms

Conclusions

• 1. The limits of settling of fragmental particles fix the width of scattering of a fraction or the distribution zone of its mass. The width of scattering of a fraction is related mostly to the lower limit of sedimentation, which depends on the size of the particles, and the parameters of the acting waves and slopes of the underwater relief.

• 2. The character of sedimentation is determined by the relation between the lower limit of sedimentation Z and erosion H_e. When Z>H_e the particles are carried beyond the limits of the shoal and after deposition become motionless. This process occurs more intensely the greater the difference between Z and H_e. With a decrease of this difference the removal of particles decreases markedly and most of them can circulate for a long time within the shoal, slowly adding material to its outer edge. When Z≤H_e the fragmental material remains entirely on the shoal. During wave action it is mobilized and is capable of continued longshore migrations. The process of alluviation — the delivery of material toward the water's edge—takes place when Z< H_e. The main prerequisites for this are a sufficient size of the fragments and quite gentle slopes of the shoal.

• 3. The regularities obtained can be used for forecasting the deposition of sediments in the shore zone of large water bodies.