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Soft Sediment Deformation Structures in the Sediment Deposits of Ganga River and Its Oxbow Lakes in Parts of Indo-Gangetic plain: Implications for Quake Proxies and Paleoseismicity Tracking

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International Journal of Geosciences 2023年第1期14卷 75-93页

作者： Gufran Ali Mohd Sajid Mohammad Shamim Khan Department of Geology AMU Aligarh India

The Late Quaternary thick sedimentary fills of the Ganga basin predominantly consist of unconsolidated fluvial sandy deposits which are often intercalated with mud. These deposits at various places record the evidence of earthquakes, which occurred in the recent geological past. The evidence is contained and manifested in the form of Soft Sediment Deformation Structures (SSDSs). Saturated sediments/muds/soils are liquefied by earthquake tremors which either generate SSDS or produce structural discordance in the pre-existing sedimentary structures. The present study reports the occurrence of SSDS, e.g. load and associated flame structures, clastic dikes and sill structures, slump structures and sedimentary breccias, etc. from the Ganga River and adjacent oxbow lake sediment deposits. An attempt has been made to establish the origin of soft sediment structures of this region in accordance with its neotectonic history and in turn, identification of seismic structural proxies to delineate paleoseismic events in this region with futuristic implications. The preservation of soft sediment deformation structures in large numbers with multiple geomorphology and scale, in the river and adjoining lake sediments, is indicative of frequent earthquakes of high magnitude consequent to tectonic activism in the Himalayan region.

关键词： Quaternary Sediments flood plain Central Ganga Basin Sediment Dynamism Himalayan Uplift Paleoquakes

THE　ROLE　PLAYED　BY　WASH　LOAD　DEPOSITION　IN　THE　FORMATION　OF　DIFFERENT　RIVER　PATTERNS

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International Journal of Sediment Research 1994年第3期 156-165页

作者： Zhaohui Wan Jinn Gao( Institute of Water Conservancy & Hydroelectric power Research, 100044P.O.Box 366,Beijing,China.)

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关键词： River pattern wash load deposition main channel flood plain

EFFECTS OF FLOW INTENSITY, OBSTACLE ALIGNMENT AND CROSS-SECTION GEOMETRY ON SCOUR AT BRIDGE ABUTMENTS

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International Journal of Sediment Research 2002年第2期17卷 102-113页

作者： A. H. CARDOSO1, J. S. SANTOS2 and M. ROCA3 EFFECTS OF FLOW INTENSITY, OBSTACLE ALIGNMENT AND CROSS-SECTION GEOMETRY ON SCOUR AT BRIDGE ABUTMENTS A. H. CARDOSO1, J. S. SANTOS2 and M. ROCA3 EFFECTS OF FLOW INTENSITY, OBSTACLE ALIGNMENT AND CROSS-SECTIO Associate Professor Instituto Superior Técnico Department of Civil Engineering and Architecture Av. Rovisco Pais 1049-001 Lisboa Civil Engineer GIBB Angola LAWGIBB group member Rua Augusto Tadeu Bastos 3 1° - 1 P.O. Box 35 I-C Luanda Teaching Assistant Universidad Politécnica de Catalunha Departamento de Ingenieria Hidráulica Marítima y Ambiental Jordi Girona1-3D1 08034 Barcelona

Experiments are reported on the effects of flow intensity, obstacle alignment and cross-section geometry on the equilibrium scour depth around abutments. The effect of flow intensity was studied for clear-water flow conditions, the obstacle alignment was studied for a wide range of angles of the obstacle with the flow direction, and tests on the cross-section geometry apply only to the case where the abutment extends into the main channel of a compound cross-section (two-stage channel). The channel bank and flood plain were built up with sand. The hypothesis of zero scour for flow velocities smaller than approximately 50% of the threshold velocity for the beginning of motion in the approaching flow cannot be rejected; maximum scour occurs for obstacles protruding at right angle from the cross-section walls, the reduction being small when obstacles point upstream; compared with rigid banks, the scour depth seems to be significantly reduced when channel bank and flood plain are constituted of alluvial material.

关键词： Flow intensity Obstacle alignment Equilibrium scour depth Threshold velocity flood plain

LOCAL SCOUR AROUND BRIDGE ABUTMENTS

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International Journal of Sediment Research 2002年第1期17卷 48-74页

作者： Er. Shri Ram CHAURASIA1 and Pande B.B. LAL2 1 Assistant Professor, Civil Engineering Department, Madan Mohan Malaviya Engineering College, Gorakhpur-273 010 (U.P.) India, 2 Dr., Principal, Mada Assistant Professor Civil Engineering Department Madan Mohan Malaviya Engineering CollegeGorakhpur-273010 (U.P.) India Dr. Principal Madan Mohan Malaviya Engineering College Gorakhpur-273010(U.P.) India

This paper summarizes the design equations for local scour depth around bridge abutments as proposed by different investigators, and also the different factors, affecting the scour depth. Methods for the estimation of local scour depth based on dimensional analysis are also presented. The design methods based on empirical relations such as flow depth, flow intensity, sediment characteristics, abutments shape and size, alignment, and approach channel geometry are also discussed. Since clear-water scour is the maximum scour depth, the equation for clear-water scour is recommended for the computation of local scour depth around bridge abutments for uniformly and non- uniformly graded sediments.

关键词： Local scour Bridge abutments flood plain Scour depth

Frequency of floodplain Spills in the Tisza River Valley at Vylok (Transcarpathia, Ukraine)

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Journal of Geological Resource and Engineering 2021年第1期9卷 1-12页

作者： Tibor Izhak Department of Geography and Tourism Ferenc Rakoczi II Transcarpathian Hungarian College of Higher EducationBerehove 90202TranscarpathiaUkraine

Record-breaking floods occurred in the autumn of 1998 and the spring of 2001 in the lowlands of Transcarpathia,as well as in the areas of Hungary and Romania bordering Ukraine,which caused severe *** research was to determine the frequency of *** fluctuation of precipitation values brings about the increased frequency of the rivers’inundation as *** research is based on the data of the Tisza River’s inundation onto the flood plain near Vylok,as well as the precipitation data of the Rakhiv meteorological *** data series include the data of the latest 46 years(1970-2015),highlighting the pre-flood period of *** evaluate the data,we used linear trend analysis,which was edited using the Microsoft Excel spreadsheet *** results of the study showed that no particular changes in precipitation were observed,but the frequency of flood waves and the coverage of the floodplain with water showed a gradually increasing *** results of studying the amount of precipitation and the Tisza River’s inundation:in recent decades the frequency of flood wave formation and the coverage of the flood plain with water show a gradually increasing tendency.

关键词： Transcarpathia floods precipitation flood plain inundation