Transport of solid material to the coastal zone near Gelendzhik after extremely heavy rains

Effect of an extreme shower (July 6–7, 2012) on the hydrological-morphological processes in the basins of small mountain rivers: Case study of the Ashamba R.

“…Therefore, the passage of extreme flood of July 6-7, 2012 caused many col lapses and landslides on the seashore and the southern slopes of the massif, accompanied by the appearance on the shore of coarse clastic rock with a small admix ture of fine soil (loam) and the falling of large pines that have grown on the slopes and bluffs [2,7]. The rock material that had appeared in the coastal zone was partially involved in the alongshore sediment flow during subsequent storms and thus contributed to some widening of beaches [6].…”

“…In the sites of crack openings at the mouths of intermittent watercourses, large amounts of debris (mostly rubble with admixture of boulders and loams) were discharged onto the seashore [2,6,7]. After the following wave processing of the discharged material, the width of the beach increased to 10 m in some places.…”

“…Damage to vegetation or structures, not strong enough, was recorded. The erosion of soils and, all the more, bedrocks took place only in unstable relief areas-mounds and hol lows [6].…”

“…Large fragments of construction ele ments, fallen trees, and beds of dense gray clay up to 0.5 m in thickness accumulated on the bed along the foot of the cone. According to data in [6], the volume of solid material discharged by the river and deposited immediately at the mouth (excluding fine fractions, which were carried farther into the sea) amounted to 8-10 thousand m 3 .…”

“…This spit has formed and changed as a result of wave induced trans formation during several subsequent medium strength storms. According to [6], it first was a small gravel island lying on a frame of the trunks of large trees brought by the river; however, two months later, after several storms, a gravel spit formed right from the mouth (Fig. 4b).…”