Geology, geography and global energy

Scientific and Technical Journal

The transformation of river Valley Ashamba and Blue Bay’s relief during catastrophic floods

2014. №4, pp. 157-166

Yevsyukov Yuriy D. - C.Sc. in Geography, Leading research assistant, Southern Branch of P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, 1g Prostornaya st., Gelendzhik, Krasnodar region, 353467, Russian Federation, evsgeol@rambler.ru

Rudnev Valeriy I. - Younger Research Assistant, Southern Branch of P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, 1g Prostornaya st., Gelendzhik, Krasnodar region, 353467, Russian Federation, evsgeol@rambler.ru

Kuklev Sergey B. - C.Sc. in Geography, Head of Laboratory, Southern Branch of P. P. Shirshov Institute of Oceanology, Russian Academy of Sciences, 1g Prostornaya st., Gelendzhik, Krasnodar region, 353467, Russian Federation, kuklev@ecologpro.ru

The earth's surface formed by the action of endogenous and exogenous processes. Originally created contrast relief further undergoes gradual equalization, which is accompanied by weathering, denudation, erosion, etc. Individual actions of various factors or their combination form different-sized blocks, grabens, gorges. On their slopes occur landslides, mudslides. In the mouths of mountain rivers formed alluvial fans. From many forms of relief they differ smallest study. Interest to them appeared in connection with catastrophic flooding on July, 6th, 2012. An unprecedented rainfall caused the formation of a devastating mudslide. Mudstone material at the mouth of the river Ashamba was formed spit and underwater alluvial fan. Food debris flow dramatically changed bottom relief of the Blue Bay, the depth of which decreased by 2-2,5 m. Based on echo sounding route profiles calculated volume of debris flow. All together stimulated necessity to define sources of occurrence of such a huge mass of products flooding. In this regard, a study river valley Ashamba, eastern foot of Doob mountain, alluvial fans and their structure. Received over 100 photos most expressive effects of the flood. At the mouth of one of the mountain valleys previously formed alluvial fan was В«cutВ» into two parts, between which formed the canyon. On its vertical sides exposed heterogeneous layers of paleo sediment. They are a kind of indicator of mudflows which occurred, perhaps, in recent times. Almost all of the valley slope have undergone to strong erosion. Their depth and width increased by 1,5-2 m and the side marked destroyed layers of marl. Near the mouth of the river Ashamba in ancient alluvial fan a powerful flood washed away the water trench with three (0,5 m) horizons strongly cemented fragments of rocks.

Key words: рельеф, речная долина, бухта, наводнение, селевой поток, донная поверхность, эндогенные процессы, конус выноса, каньон, relief, river valley, bay, flood, mudflow, bottom surface, endogenous processes, alluvial fan, canyon

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