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SPATIAL-TEMPORAL DISTRIBUTION, GENESIS AND TRANSPORTATION OF BOTTOM SEDIMENTS
Abstract
Genesis, transport and accumulation of settled sediments of mountain rivers are such random processes in time and space, which are defined by the river flow rate (Q m3/s?c), height of the basin (IпїЅ), the inclination of the river and basin geology. Genesis and the volume of river sediment is the function of the climate and, in accordance with its cycles, it increases during the warming period and decreases as the temperature falls. The main natural factors for sediment formation are the glacier, erosion, landslides and flax. Sediment transportation пїЅ the process of sediment transportation by the flow represents many variable functions, which are mainly described by Chezy-Maning and Airy laws. Aside from the aforementioned laws, this process is also subject to the regularity of dependence between the maximal diameter of the sediment (dmax) and the speed of the river (V, m/sec) in the head race of a water reservoir. In some places, the river crosses an uplifted ridge or пїЅepirogenic thresholdпїЅ and the submersible lowland. The river saws such threshold to create the so-called "equilibrium balanced riverbed" of respective characteristics. In case if the speed of the threshold uplift is more than the speed of the riverbed cut, then the depression is created, in which the river permanently deposits sediments in order to create riverbed with a corresponding inclination, so called equilibrium riverbed. Some rivers use the significant part of sediments for the compensation of stagnations caused by "flax dam" - alluvian fan of the flax. The result of such processes is the creation of Chiori grove, accumulative plain-terraces of Saglolo and Chrebalo in the basin of river Rioni, and the creation of Tianeti plain in upstream of river Iori and many more. The significant part of sediments is spent on the formation of sanding prisms of water reservoirs. River consumes one part of the remaining settled sediments to create balanced riverbed in the submersible lowlands and to neutralize the effect of sea eustasy. The second part of sediments is spent on the formation of delta, permanent filling of coastal beaches and creation of accumulative formations in the sea. The mountain reservoir is in conflicting relations with the sea coast protection, and the security of population and infrastructure at the head race. Hence, the genesis of settled sediments of the river, places of natural accumulation and sediment granulometry should be taken into account when choosing the place for reservoir. The optimal places for the construction of water reservoir dams are epeirogenic thresholds, since the dam is uplifted there and thus, the operation period of water reservoir is relatively longer.
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References15
Barishnikov N., Samuseev E., Simonov A. Hydraulic resistance of river channels. RAS IWP, VI Conference “Dynamics and thermic of rivers, reservoirs and sea coastal zone”, Moscow, Russia, 12-13 (in Russian), 2004
Chavan R, Sharma A, Kumar B. Effect of downward seepage on turbulent flow characteristics and bed morphology around bridge piers. Journal of Marine Science and Application. Springer, 1-3, 2017
Cienciala P., Pasternack G.B. Floodplain inundation response to climate, valley form, and flow regulation on a gravel-bed river in a Mediterranean-climate region. Geomorphology. Elsevier, vol. 282, 1-17, 2017
Colin B. Phillips1, Douglas J. Jerolmack. Self-organization of river channels as a critical filter on climate signals. Science, vol. 352, Issue 6286, 694-697, 2016
Elhakeem M, Papanicolaou AT, Tsakiris AG. A probabilistic model for sediment entrainment: The role of bed irregularity. International Journal of Sediment Research. Elsevier, Nov 29, 2016
Kamal El Kadi Abderrezzaka, Andrés Die Morana, Pablo Tassia, Riadh Ataa, Jean-Michel Hervoueta. Modelling river bank erosion using a 2D depth-averaged numerical model of flow and non-cohesive, non-uniform sediment transport. Advances in Water Resources, Elsevier, vol. 93, Part A, 75-88, 2016
Kondolf G.M., Gao Y., Annandale G.W., Morris G.L., Jiang E., Zhang J., Cao Y., Carling P., Fu K., Guo Q., Hotchkiss R., Peteuil C., Sumi T., Wang H-W., Wang Z., Wei Z., Wu B., Wu C., and Yang C.T. Sustainable sediment management in reservoirs and regulated rivers: Experiences from five continents. Earth’s Future, 2, 256–280, 2014
Kordzakhia G., Shengelia L., Tvauri G., Dzadzamia M. Impact of Modern Climate Change on Glaciers in Georgia. Bulletin of Georgian National Academiof Sciences, vol. 10, №4, 56-63, 2017
Matchavariani L., Metreveli G., Alaverdashvili M., Lagidze L., Svanadze D., Gulashvili Z. Bregvadze G. Results of Field Experiments of Reservoirs' Siltation for Harmonious Realization of Hydropower and Coastline Problems.Second International Conference on Science, Engineering & Environment, Osaka City, Japan, 639-644, 2016
Metreveli G., Matchavariani L. Research Method of Silting the Mountain Reservoirs under the Current Climate Change. Journal of Water Resources and Ocean Science. Science Publishing Group, vol. 5, No. 2, 22-27, 2016
Mohajeri S.H., Righetti M., Wharton G., Romano G.P. On the structure of turbulent gravel bed flow: Implications for sediment transport. Advances in Water Resources, Elsevier, 92, 90-104, 2016
Morris G.L., Fan J. Reservoir Sedimentation Handbook, McGraw-Hill Book Co., New York, 1998
Stephens T. Study shows how river channels adjust to large sediment supplies. Santa Cruuz. University of California. Newscenter, 4, 2017
Tharme R.E. Global perspective on environmental flow assessment: emerging trends in the development and application of environmental flow methodologies for rivers. Rivers Research and Application 19(5-6), 619-639, 2003
Vogel H., Wessels M., Albrecht C., Stich H.-B., and Wagner B.. Spatial variability of recent sedimentation in Lake Ohrid (Albania/Macedonia). Biogeosciences, 7, 3333-3342, 2010
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