THE EFFECT OF THE INITIAL BED PERTURBTION TO THE SAND BAR FORMATION AND EVOLUTION PROCESS

San ye House Village are located in Farming-pastoral zone of eastern Inner Mongolia after a hundred years of development history, from mainly nomadic settlements into agricultural and pastoral settlements. The evolution of the settlements' pattern experienced a total of three stages. With the combination of different periods of settlement pattern analysis, the characteristics of San ye House village settlement pattern development is studied and the reasons for its formation and evolution process are presented.

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Development of a Numerical Model to Analyze the Formation and Development Process of River Mouth Bars

Journal of Korean Society of Coastal and Ocean Engineers ◽

10.9765/kscoe.2021.33.6.308 ◽

2021 ◽

Vol 33 (6) ◽

pp. 308-320

Author(s):

Yeon-Joong Kim ◽

Joung-Woon Woo ◽

Jong-Sung Yoon ◽

Myoung-Kyu Kim

Keyword(s):

Formation Process ◽

Numerical Models ◽

Sediment Supply ◽

Management Approach ◽

Sediment Discharge ◽

Duration Of Action ◽

Sand Bars ◽

Tidal Sand ◽

Sand Bar ◽

Bar Formation

An integrated sediment management approach that includes the recovery of the amount of declined sediment supply is effective as a fundamental solution to coastal erosion. During planning, it is essential to analyze the transfer mechanism of the sediments generated from estuaries (the junction between a river and sea) to assess the amount and rate of sediment discharge (from the river to sea) supplied back to the coast. Although numerical models that interpret the tidal sand bar flushing process during flooding have been studied, thus far, there has been no study focusing on the formation and development processes of tidal sand bars. Therefore, this study aims to construct wave deformation, flow regime calculation, and topographic change analysis models to assess the amount of recovered sediment discharge and reproduce the tidal sand bar formation process through numerical analysis for integrated littoral drift management. The tidal sand bar formation process was simulated, and the wave energy and duration of action concepts were implemented to predict the long-term littoral movement. The river flux and wave conditions during winter when tidal sand bars dominantly develop were considered as the external force conditions required for calculation. The initial condition of the topographic data directly after the Maeupcheon tidal sand bar flushing during flooding was set as the initial topography. Consequently, the tidal sand bar formation and development due to nearshore currents dependent on the incident wave direction were reproduced. Approximately 66 h after the initial topography, a sand bar formation was observed at the Maengbang estuary.

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APPLICABILITY OF 3D BEACH EVOLUTION MODEL WITH WAVE-CURRENT INTERACTION FOR SAND BAR FORMATION IN A RIVER MOUTH

Journal of Japan Society of Civil Engineers Ser B2 (Coastal Engineering) ◽

10.2208/kaigan.72.i_697 ◽

2016 ◽

Vol 72 (2) ◽

pp. I_697-I_702

Author(s):

Masamitsu KUROIWA ◽

Ryohei ANAN ◽

Yoko SHIBUTANI ◽

Hajime MASE ◽

Yuhei MATSUBARA

Keyword(s):

River Mouth ◽

Evolution Model ◽

Current Interaction ◽

Sand Bar ◽

Bar Formation

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ASCA Study of Shaplay Supercluster

Symposium - International Astronomical Union ◽

10.1017/s0074180900115244 ◽

1998 ◽

Vol 188 ◽

pp. 300-301 ◽

Cited By ~ 1

Author(s):

H. Hanami

Keyword(s):

Temperature Distribution ◽

Evolution Process ◽

Observational Cosmology ◽

Clusters Of Galaxies ◽

Formation And Evolution

We observed five clusters of galaxies in Shapley supercluster with ASCA; A3562, SC13290-313, SC1327-312, A3558 and A3556, which are candidates for interacting clusters since their separation and relative velocities are only 1Mpc and 700-1000km/s (e.g. Raychaudhury et al. '91, Breen et al. '94, Scaramella et al. '89). Main purpose of mapping observations is to make clear the formation and evolution process of the clusters of galaxies in a supercluster. ASCA gives essential informations of ICM like the temperature distribution related to the dynamics; the interactions due to the infalling and merging events. They are important tests for observational cosmology (e.g. Hanami '93).

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Sand Bar Evolution Process Numerical Simulation Analyze Based on two Dimensional Numerical Model

Journal of Physics Conference Series ◽

10.1088/1742-6596/1885/5/052047 ◽

2021 ◽

Vol 1885 (5) ◽

pp. 052047

Author(s):

Caodong Jiang ◽

Liangchao Ma ◽

Dongfeng Li ◽

Hongwu Zhang ◽

Zihao Li

Keyword(s):

Numerical Simulation ◽

Numerical Model ◽

Evolution Process ◽

Two Dimensional ◽

Sand Bar

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Seismic P-wave receiver function modelling of Archean cratonic crust: A global perspective

10.5194/egusphere-egu2020-9666 ◽

2020 ◽

Author(s):

Poulami Roy ◽

Kajaljyoti Borah

Keyword(s):

Continental Crust ◽

Receiver Function ◽

Function Analysis ◽

Crustal Thickness ◽

Global Perspective ◽

P Wave ◽

Evolution Process ◽

S Wave ◽

Economic Significance ◽

Formation And Evolution

<p>Cratons are representative of the oldest cores of continental crusts. Study of cratons is important &#160;as they preserve the pristine nature of continental crusts as well as they have economic significance as a major source of the world's mineral deposits. The crustal thickness, crustal composition, structure and physical properties of crust-mantle transition (the Moho) are the key parameters for understanding the formation and evolution of continental crust. The ratio of &#160;seismic P-wave and S-wave velocity (Vp/Vs) is used as a parameter to understand the petrologic nature of the Earth's crust. Using these parameters, we address the crustal properties of all Archean cratons. The teleseismic P-wave receiver function analysis reveals that all the Eoarchean (4-3.6 Ga) cratons (Superior, North Atlantic Craton, North China Craton, Yilgarn, Zimbabwe, Kaapvaal) have crustal thickness ranges between 34-42 km and Vp/Vs ratio 1.68-1.79, the Paleoarchean (3.6-3.2 Ga) cratons (Baltic shield, Pilbara, Tanzania, Grunehogna) have 29-52 km crustal thickness and Vp/Vs ratio 1.7-1.85, the Mesoarchean (3.2-2.8 Ga) cratons (Sao Francisco, Guapore, Yangtze, Antananarivo) have 36-53 km thickness and Vp/Vs ratio 1.7-1.9, and Neoarchean (2.8-2.5 Ga) cratons (Guiana, Anabar, Gawler, Napier, Tarim) have 36-59 km thickness and Vp/Vs ratio 1.64-1.95. The nature of crust-mantle transition is overall sharp and flat. &#160;We also found that the crusts which are stabilized earlier, are thinner compared to the later stabilized crusts. Our findings are well-correlated with the craton evolution process predicted by Durrheim and Mooney (1994), where older crusts are thin due to delamination process and relatively younger crusts are thick due to basaltic underplating. Our result of higher Vp/Vs ratio in the relatively younger crusts corroborates with the mafic nature of the crust whereas the older crusts are felsic-intermediate resulting lower Vp/Vs ratio. Our study is unique as it includes most of the global cratons and suggests a global model of continental crust formation and evolution process.</p>

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Experimental Study on Changes of Sloping Sandy Bed Profile under Breaking Waves

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.212-213.163 ◽

2012 ◽

Vol 212-213 ◽

pp. 163-168

Author(s):

Yun Pan ◽

Yong Zhou Cheng ◽

Qing Feng Li ◽

Wen Cheng Wang

Keyword(s):

Wave Breaking ◽

Orbital Motion ◽

Breaking Waves ◽

Coastal Structures ◽

Wave Flume ◽

Sand Ripple ◽

Wide Range ◽

Wave Heights ◽

Formation And Evolution ◽

Sand Bar

The wave breaking forces can exacerbate sediment transport, and lead to erosion of the seabed, coastal deformation and destruction of coastal structures. The experiment is carried out in a wave flume with a 1:30 sloping sandy seabed. A wide range of measurements from the regular wave runs are reported, including time series of wave heights, changes of bed profile. The video records are analysed to measure the time development of the seabed form and the characteristics of the orbital motion of the sand in the wave breaking region. The location and wave height at wave breaking point is measured by experiment. Formation and evolution of sand ripple and sand bar are studied under the breaking waves. It is found that effect of bed surface on wave breaking zone is more significant than wave non-breaking.

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The Sand Bar Formation and Its Impact on the Mangrove Ecosystem:A Case Study of Kadalundi Estuary of Kadalundi River Basin in Kerala, India

Current World Environment ◽

10.12944/cwe.11.1.08 ◽

2016 ◽

Vol 11 (1) ◽

pp. 65-71 ◽

Cited By ~ 1

Author(s):

K B. Bindu ◽

G Jayapal

Keyword(s):

Avicennia Marina ◽

Mangrove Ecosystem ◽

Urban Waste ◽

Sand Bars ◽

Mangrove Ecosystems ◽

Mangrove Vegetation ◽

Sand Bar ◽

Kerala State ◽

Bar Formation

Mangrove ecosystems are prone to die due to both anthropogenic and natural effects. The present study is a case study of how the formation of sand bars affects the natural mangrove ecosystem and becoming a threat to its rich biodiversity of flora and fauna. The Kadalundi – Vallikkunnu Community Reserve located in Kozhikode and Malappuram Districts in Kerala State is the first community reserve of Kerala, declared in 2007 which spread across 1.5 sq. km. andthis area includes Kadalundi bird sanctuary, mangroves and estuarine. These area mainly affected by numerous biotic interferences like over fishing, collection of oyster and mussels, mining of sand and lime and also retting of coconut. The formation of sand bars at the mouth of the river has resulted in the massive die back of the mangrove vegetation, especially that of Avicennia Marina which is one of the five species of mangroves found in the Kadalundi – Vallikunnu community reserve. The illegal utilization of land for coconut plantation, urbanization and dumping of urban waste near the mouth of the river had made the problem highly complicated. The present study highlights the need for urgent measures to be adopted from the authorities to ensure community participation for restoration of community reserve.

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