Architectural Changes and Preferential Sand Deposition In a Confined Channel–Levee System Forced to Surmount a Ridge Crest

Author(s):  
EFTHYMIOS K. TRIPSANAS ◽  
EDDY LEE ◽  
WILLEM HACK ◽  
R. CRAIG SHIPP
2018 ◽  
Author(s):  
Brian E. Bodenbender ◽  
◽  
Edward C. Hansen ◽  
Brian P. Yurk ◽  
Suzanne J. DeVries-Zimmerman ◽  
...  
Keyword(s):  

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4406
Author(s):  
Tadaharu Ishikawa ◽  
Hiroshi Senoo

The development process and flood control effects of the open-levee system, which was constructed from the mid-18th to the mid-19th centuries, on the Kurobe Alluvial Fan—a large alluvial fan located on the Japan Sea Coast of Japan’s main island—was evaluated using numerical flow simulation. The topography for the numerical simulation was determined from an old pictorial map in the 18th century and various maps after the 19th century, and the return period of the flood hydrograph was determined to be 10 years judging from the level of civil engineering of those days. The numerical results suggested the followings: The levees at the first stage were made to block the dominant divergent streams to gather the river flows together efficiently; by the completed open-levee system, excess river flow over the main channel capacity was discharged through upstream levee openings to old stream courses which were used as temporary floodways, and after the flood peak, a part of the flooded water returned to the main channel through the downstream levee openings. It is considered that the ideas of civil engineers of those days to control the floods exceeding river channel capacity, embodied in their levee arrangement, will give us hints on how to control the extraordinary floods that we should face in the near future when the scale of storms will increase due to the global climate change.


1974 ◽  
Vol 21 (4) ◽  
pp. 405-413 ◽  
Author(s):  
E.E. Davis ◽  
C.R.B. Lister
Keyword(s):  

1991 ◽  
Vol 69 (7) ◽  
pp. 1593-1599 ◽  
Author(s):  
César S. B. Costa ◽  
Ulrich Seeliger ◽  
César V. Cordazzo

We studied the effect of nutrient status and sand movement on the population biology of Panicum racemosum Spreng. over a 5-year period (1982–1986) on mobile, semifixed and fixed coastal foredune habitats in southern Brazil. The soils were deficient in nitrate, phosphate, and potassium (<0.5, 0.2–1.2, and 3–5 mg/kg, respectively) in all habitats, and a gradient of decreasing availability existed from the mobile to the fixed dunes. Half-lives of leaves were shorter in the fixed dune as compared with the mobile dune. Similarly, half-lives of leaves were shorter in summer than in winter. Experiments using cuttings of P. racemosum tillers showed that as P. racemosum plants grew, so did the deposition of sand on mobile foredunes. The mechanical deposition of sand itself did not stimulate P. racemosum growth. The deposition of saline sand provided a substrate that supported vertical growth of P. racemosum rhizomes and tillers and was a source of adsorbed nutrients. Also, active sand deposition limited the invasion of frontal dunes by other species. Panicum racemosum populations changed from "invader" to "mature" to "regressive" age states over a 5-year period, apparently in response to the spatial patterns of sand deposition and salt spray input. Key words: Panicum, leaf demography, growth vigour, sand dunes, temporal changes.


Geology ◽  
1994 ◽  
Vol 22 (4) ◽  
pp. 375-379 ◽  
Author(s):  
M. R. Perfit ◽  
D. J. Fornari ◽  
M. C. Smith ◽  
J. F. Bender ◽  
C. H. Langmuir ◽  
...  

2000 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt

Abstract The results of experimental study of pressure variations inside core box during resin bonded sand filling process are reported. The test core specimens were produced using Laempe® Test Specimen Curing Machine L 1. A special pressure measurement system was designed and built with safety and portability requirements of the foundry environment. Special experiments were conducted to establish the effect of sand deposition on vent permeability.


2015 ◽  
Vol 143 (24) ◽  
pp. 244119 ◽  
Author(s):  
Huai Ding ◽  
Huijun Jiang ◽  
Zhonghuai Hou

The Holocene ◽  
2016 ◽  
Vol 27 (4) ◽  
pp. 579-593 ◽  
Author(s):  
Stephen A Wolfe ◽  
Olav B Lian ◽  
Christopher H Hugenholtz ◽  
Justine R Riches

The Bigstick and Seward Sand Hills are possibly two of the oldest dune fields within the late Wisconsin glaciated regions of the Northern Great Plains. As with most Northern Great Plains dune fields, source sediments are former proglacial outwash sands. Thus, Holocene dune construction is primarily related to spatial–temporal variations in surface cover and transport capacity, rather than renewed sediment input. However, eolian landscape reconstructions on the Northern Great Plains have been temporally constrained to recent periods of activity, as older episodes of deposition are typically reworked by younger events. In this study, sediment cores from shallow lacustrine basins and interdune areas provide an improved record of Holocene eolian sand deposition. Eolian sand accumulation in the interdunes and basins occurred between 150 and 270 years ago, 1.9 and 3.0 ka, 5.4 and 8.6 ka, and prior to ca. 10.8 ka. These episodes of sand accumulation were bracketed by lacustrine deposition and soil formation, which represented wetter conditions. Other than mid-Holocene dune activity, which may be related to peak warmth and aridity, most periods of eolian sand accumulation coincided with cooler but drier climatic events such as the Younger Dryas, late-Holocene cooling prior to the Medieval Climatic Anomaly, and the ‘Little Ice Age’. These depositional episodes are also spatially represented by other dune fields in the region, providing a broad-scale view of the connections between past climatic events and eolian landscape evolution on the Northern Great Plains.


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