From picture to porosity of river bed material using Structure-from-Motion with Multi-View-Stereo

Geomorphology ◽  
2018 ◽  
Vol 306 ◽  
pp. 80-89 ◽  
Author(s):  
Lydia Seitz ◽  
Christian Haas ◽  
Markus Noack ◽  
Silke Wieprecht
Keyword(s):  
Structure From Motion ◽  
River Bed ◽  
Bed Material

scholarly journals Grain sorting in the morphological active layer of a braided river physical model

2015 ◽  
Vol 3 (4) ◽  
pp. 577-585 ◽  
Author(s):  
P. Leduc ◽  
P. Ashmore ◽  
J. T. Gardner
Keyword(s):  
Grain Size ◽  
Numerical Modeling ◽  
Active Layer ◽  
Bedload Transport ◽  
Scale Model ◽  
Active Layer Thickness ◽  
Braided River ◽  
River Bed ◽  
Physical Scale ◽  
Bed Material

Abstract. A physical scale model of a gravel-bed braided river was used to measure vertical grain size sorting in the morphological active layer aggregated over the width of the river. This vertical sorting is important for analyzing braided river sedimentology, for numerical modeling of braided river morphodynamics, and for measuring and predicting bedload transport rate. We define the morphological active layer as the bed material between the maximum and minimum bed elevations at a point over extended time periods sufficient for braiding processes to rework the river bed. The vertical extent of the active layer was measured using 40 hourly high-resolution DEMs (digital elevation models) of the model river bed. An image texture algorithm was used to map bed material grain size of each DEM. Analysis of the 40 DEMs and texture maps provides data on the geometry of the morphological active layer and variation in grain size in three dimensions. By normalizing active layer thickness and dividing into 10 sublayers, we show that all grain sizes occur with almost equal frequency in all sublayers. Occurrence of patches and strings of coarser (or finer) material relates to preservation of particular morpho-textural features within the active layer. For numerical modeling and bedload prediction, a morphological active layer that is fully mixed with respect to grain size is a reliable approximation.

Effects of large-scale rubber farm on soil erosion and river bed material in the upper Mekong Basin

2014 ◽  
pp. 2305-2312
Author(s):  
Xiongdong Zhou ◽  
Zhaoyin Wang ◽  
Bofu Yu ◽  
Lydia Seitz
Keyword(s):  
Soil Erosion ◽  
Large Scale ◽  
Mekong Basin ◽  
River Bed ◽  
Bed Material

scholarly journals Rapid River Bed Recovery after the In-Channel Mining: The Case of Vistula River, Poland

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 623
Author(s):  
Tadeusz Molenda ◽  
Agnieszka Czajka ◽  
Stanisław Czaja ◽  
Barbara Spyt
Keyword(s):  
Mining Area ◽  
Negative Influence ◽  
Vistula River ◽  
River Bed ◽  
Natural Flow ◽  
Average Water ◽  
River Reach ◽  
Bedload Sediment ◽  
Bed Material ◽  
Short Time

The effects of in-channel wet-pit mining is nowadays widely discussed in terms of negative influence of the created pits on the river ecosystem and fluvial processes. The pits induce an alteration of natural flow or sediment transport. This paper describes the post-mining channel recovery observed in a relatively short time in a gravelly sand bed lowland river. The study was based on repeated bathymetry of the channel and grain size analyses of bed material taken from the mining area and its surrounding upstream and downstream pit. We also use calculations of possible bedload sediment movement in the studied river reach. We noticed that the excavation pit exceeded the maximum depth of 8.8 m in 2014 and, immediately after the end of mining, the bedload started to infill the pit. The bathymetric measurements in 2019 indicated that the process of pit infill was completed after five years, though the former pit is refilled with material finer than the natural bedload observed in the discussed river reach, and consists mainly of sand. The studied process of pit infilling runs continuously, even during the annual average water stages.

scholarly journals The Effect Of Lamong River Flow Diversion To Bed Surface Degradation

2020 ◽  
Vol 22 (2) ◽  
pp. 117-126
Author(s):  
Cahyono Ikhsan
Keyword(s):  
River Flow ◽  
Mass Density ◽  
Fixed Bed ◽  
Maximum Flow ◽  
Flow Speed ◽  
Relative Mass ◽  
Mobile Bed ◽  
River Bed ◽  
Bottom Width ◽  
Bed Material

Abstract Kali Lamong River with a trapezoidal channel shape has a bottom width of about 30 m, a top width of 40 m and a depth of 3.5 m. In one of the river segments, the basis is in the form of a fixed bed and it is assumed that there is no sediment transport in this section. On the downstream side after the fixed bed section, the river segment is a mobile bed with river bed material that has an average grain diameter of 1.5 mm, a relative mass density of 2.6, and porosity of 0.3. Flowrate with Q50 is 1000.00 m3/sec with a maximum flow speed of 15 m/sec. Riverbed degradation will occur initially at the upstream point in the fixed and mobile beds. Depth of riverbed degradation calculated by the Parabolic model of 80.00 cm / year based on the solution of the equation.

scholarly journals FIELD SURVEY OF BED MATERIAL EXCHANGE THICKNESS ON DIFFERENT RIVER BED TYPE

2014 ◽  
Vol 70 (4) ◽  
pp. I_1003-I_1008
Author(s):  
Masaaki YANO ◽  
Yasuharu WATANABE ◽  
Hiroki YABE ◽  
Kazuyoshi WATANABE
Keyword(s):  
Field Survey ◽  
River Bed ◽  
Bed Material ◽  
Material Exchange

scholarly journals Evaluating the Trend of Changes in Bed Sediments Gradation over the Sistan River

2021 ◽  
Vol 11 ◽  
pp. 08-14
Author(s):  
Mahdi Motallebian ◽  
Farzad Hassanpour ◽  
Hadi Kamell
Keyword(s):  
Statistical Parameters ◽  
Uniformity Coefficient ◽  
River Bed ◽  
Distance Weighting ◽  
Study Interval ◽  
Arc Gis ◽  
Standard Classification ◽  
Bed Material ◽  
Gis Software ◽  
Inverse Distance

Sediment movement in rivers is one of the most important indicators to evaluate the health of an ecosystem. Bed load different specification such as shape, dimensions and other statistical parameters of this sediment reflect the hydraulic and hydrological conditions governing them, directly. To investigate the changes of particle aggregation of Sistan river bed, four sediment samples were collected from the Sistan river. After aggregation of sediments in the laboratory, sediment diameter (D50) and uniformity coefficient (Cu) was calculated, and using inverse distance weighting (IDW) method, the mentioned parameters for the Sistan river from Jarikeh up to the AfzalAbad plugs place were interpolated and parameters using ARC-GIS software was zoning along the river. Results showed that Sistan river bed material is sand and silt, 3 km to the beginning and at end of the study interval based on the English standard classification it is silty texture and the rest of bed is sandy texture. 11 kilometers beginning and the end of the river also from 20 +721 kilometer up to about 12 kilometers has also a good aggregation. The entire river except for the middle section of river from the 13 +244 km to extent of 4 km river bed has non-uniform soil.

scholarly journals Grain sorting in the morphological active layer of a braided river physical model

2015 ◽  
Vol 3 (3) ◽  
pp. 577-600
Author(s):  
P. Leduc ◽  
P. Ashmore ◽  
J. T. Gardner
Keyword(s):  
Grain Size ◽  
Numerical Modeling ◽  
Active Layer ◽  
Scale Model ◽  
Bed Load ◽  
Active Layer Thickness ◽  
Braided River ◽  
River Bed ◽  
Physical Scale ◽  
Bed Material

Abstract. A physical scale model of a gravel-bed braided river was used to measure vertical grain size sorting in the morphological active layer aggregated over the width of the river. This vertical sorting is important for analyzing braided river sedimentology, for numerical modeling of braided river morpho-dynamics and for measuring and predicting bed load transport rate. We define the morphological active layer as the bed material between the maximum and minimum bed elevations at a point over extended time periods sufficient for braiding processes to re-work the river bed. The vertical extent of the active layer was measured using 40 hourly high-resolution DEMs of the model river bed. An image texture algorithm was used to map bed material grain size of each DEM. Analysis of the 40 DEMs and texture maps provides data on the geometry of the morphological active layer and variation in grain size in three-dimensions. Normalizing active layer thickness and dividing into 10 sub-layers we show that all grain sizes occur with almost equal frequency in all sub-layers. Occurrence of patches and strings of coarser (or finer) material relates to preservation of particular morpho-textural features within the active layer. For numerical modeling and bed load prediction a morphological active layer that is fully mixed with respect to grain size is a reliable approximation.

In-situ measurement of river-bed sediment porosity using Structure-from-Motion image analysis

Geomorphology ◽  
2019 ◽  
Vol 338 ◽  
pp. 61-67 ◽  
Author(s):  
Mina Tabesh ◽  
Thomas Hoffmann ◽  
Stefan Vollmer ◽  
Holger Schüttrumpf ◽  
Roy M. Frings
Keyword(s):  
Image Analysis ◽  
Structure From Motion ◽  
In Situ Measurement ◽  
Bed Sediment ◽  
River Bed ◽  
River Bed Sediment
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