scholarly journals DEVELOPMENT OF 1-D RIVER BED VARIATION ANALYSIS METHOD BASED ON SEDIMENT TRANSPORT MECHANISM IN STONY BED RIVERS

2008 ◽  
Vol 52 ◽  
pp. 625-630
Author(s):  
Kengo OSADA ◽  
Shoji FUKUOKA
Keyword(s):  
Sediment Transport ◽  
Transport Mechanism ◽  
Analysis Method ◽  
Variation Analysis ◽  
River Bed

scholarly journals Hidrogeomorfologia em confluência fluvial obtusa, Guarapuava, Paraná

2021 ◽  
Vol 14 (4) ◽  
pp. 2131-2148
Author(s):  
Leandro Redin Vestena ◽  
Alessandro Kominecki
Keyword(s):  
Land Use ◽  
Sediment Transport ◽  
Liquid Mixtures ◽  
Hydraulic Characteristics ◽  
Specific Flow ◽  
River Ecosystems ◽  
River Bed ◽  
River Confluence ◽  
Land Use And Management ◽  
Junction Angle

Solid and liquid mixtures in river courses intensify in areas of river confluence, conditioned mainly by the angular opening of the junction. Knowledge of hydrosedimentological dynamics in bedrock junctions with different angular openings is essential for understanding morphological adjustment at confluences and for supporting actions for the preservation and conservation of river ecosystems. For this reason, this article presents the results of a hydrogeomorphologic study on a river confluence with an obtuse junction angle (>100º), in a plateau bedrock river, in the Serra Geral Formation. The research evaluated a fluvial segment upstream and downstream of the Pedras River and in the Pombas River tributary, in Guarapuava, Paraná, through observations and measurements of morphological and hydraulic characteristics, width, talweg depth, bed declivity and bankfull flow. Morphological adjustment in obtuse confluences is peculiar in that the fluvial junction angle conditions specific flow, erosion, sediment transport and deposition dynamics, mainly resulting from its association with the geological nature of the river bed and types of land use and management upstream of the confluence.

Variation analysis driven by small-sample data for compliant aero-structure assembly

2019 ◽  
Vol 39 (1) ◽  
pp. 101-112 ◽  
Author(s):  
Biao Mei ◽  
Weidong Zhu ◽  
Yinglin Ke ◽  
Pengyu Zheng
Keyword(s):  
Probability Distributions ◽  
Small Sample ◽  
Accurate Estimation ◽  
Production Volume ◽  
Analysis Method ◽  
Variation Analysis ◽  
Content Type ◽  
Aircraft Manufacturing ◽  
Sample Data ◽  
Structure Assembly

Purpose Assembly variation analysis generally demands probability distributions of variation sources. However, due to small production volume in aircraft manufacturing, especially prototype manufacturing, the probability distributions are hard to obtain, and only the small-sample data of variation sources can be consulted. Thus, this paper aims to propose a variation analysis method driven by small-sample data for compliant aero-structure assembly. Design/methodology/approach First, a hybrid assembly variation model, integrating rigid effects with flexibility, is constructed based on the homogeneous transformation and elasticity mechanics. Then, the bootstrap approach is introduced to estimate a variation source based on small-sample data. The influences of bootstrap parameters on the estimation accuracy are analyzed to select suitable parameters for acceptable estimation performance. Finally, the process of assembly variation analysis driven by small-sample data is demonstrated. Findings A variation analysis method driven by small-sample data, considering both rigid effects and flexibility, is proposed for aero-structure assembly. The method provides a good complement to traditional variation analysis methods based on probability distributions of variation sources. Practical implications With the proposed method, even if probability distribution information of variation sources cannot be obtained, accurate estimation of the assembly variation could be achieved. The method is well suited for aircraft assembly, especially in the stage of prototype manufacturing. Originality/value A variation analysis method driven by small-sample data is proposed for aero-structure assembly, which can be extended to deal with other similar applications.

scholarly journals ROLES OF FLOODS AND FINE SEDIMENT TRANSPORT TO WOOD LAND EXPANSION ON A GRAVEL RIVER-BED

1998 ◽  
Vol 42 ◽  
pp. 433-438 ◽  
Author(s):  
Sam-hee LEE ◽  
Koh-ichi FUJITA ◽  
Takao TSUKAHARA ◽  
Satoshi WATANABE ◽  
Koichi YAMAMOTO ◽  
...  
Keyword(s):  
Sediment Transport ◽  
Fine Sediment ◽  
River Bed

scholarly journals Morphological development of river widenings with variable sediment supply

2018 ◽  
Vol 40 ◽  
pp. 02007 ◽  
Author(s):  
Cristina Rachelly ◽  
Volker Weitbrecht ◽  
David F. Vetsch ◽  
Robert M. Boes
Keyword(s):  
Sediment Transport ◽  
Adverse Effects ◽  
Habitat Heterogeneity ◽  
Field Studies ◽  
Sediment Supply ◽  
Morphological Development ◽  
Regime Theory ◽  
Channel Response ◽  
River Bed ◽  
Experimental Flume

River widening is a common restoration approach to mitigate the adverse effects of past stream alterations on infrastructure and the riparian ecosystem by stabilizing the river bed and enhancing habitat heterogeneity. In this study, two river widening approaches, excavated and dynamic, are described for the case of moderately steep gravel-bed rivers in the Alpine foothills, with a focus on dynamic river widening. As most channelized rivers exhibit ongoing degradation due to the lack of sediment supply and efforts to restore sediment transport are increasing, the consideration of the response of river widenings to variable sediment supply is important. For this purpose, insights from regime theory are applied to river widening and several experimental flume and field studies on channel response to variable sediment supply are reviewed. Dynamic river widenings are expected to be morphologically active in weakly degraded rivers with sufficient sediment supply, while they may not be an appropriate restoration approach for highly degraded rivers due to persistent impairment of morphological activity.

STUDY ON THE IMPROVEMENT EFFECT OF APPLICATION OF ALB FOR RIVER CHANNEL TOPOGRAPHY ON RIVER-BED VARIATION ANALYSIS

2018 ◽  
Vol 74 (2) ◽  
pp. I_465-I_474 ◽  
Author(s):  
Kaho YAMAGUCHI ◽  
Keisuke YOSHIDA ◽  
Shiro MAENO ◽  
Koji MANO ◽  
Ryosuke AKOH ◽  
...  
Keyword(s):  
River Channel ◽  
Variation Analysis ◽  
River Bed ◽  
Improvement Effect
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