Evaluating short-term morphological changes in a gravel-bed braided river using terrestrial laser scanner

Geomorphology ◽  
2013 ◽  
Vol 201 ◽  
pp. 323-334 ◽  
Author(s):  
L. Picco ◽  
L. Mao ◽  
M. Cavalli ◽  
E. Buzzi ◽  
R. Rainato ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
Braided River ◽  
Short Term ◽  
Gravel Bed

scholarly journals Evaluation of short-term geomorphic changes along the Tagliamento river using LiDAR and terrestrial laser scanner surveys

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
R. Rainato ◽  
L. Picco ◽  
M. Cavalli ◽  
L. Mao ◽  
F. Delai ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Survey Methods ◽  
Laser Scanner ◽  
Sediment Supply ◽  
Qualitative Assessment ◽  
Terrestrial Laser Scanner ◽  
Short Term ◽  
Inference System ◽  
Short Period ◽  
Tagliamento River

In the recent years a change in the predominant morphology of several river environments has taken place, consisting in a reduction of the braided pattern in favor to wandering or straight configurations. This evolution seems to be due, according to the scientific community, to anthropic causes and, in particular, to the alteration of flow regimes as well as the reduction of sediment transport. Braided rivers are characterized by two or more active channels, separated by bars and fluvial islands and normally feature a high morphological dynamism. This dynamism is the result of the interaction among different elements as sediment supply, flow regime and in-channel and perifluvial vegetation. These factors have a fundamental role in the erosion and deposition processes which are the basis of the morphological changes. The aims of this study are the assessment of the short period geomorphic and volumetric changes occurred along a reach of the Tagliamento River and the comparison between the results obtained from LiDAR (Light Detection and Ranging) and TLS (Terrestrial Laser Scanner) data. The Tagliamento river is a natural gravel-bed river located in the NE of Italy, characterized by a relatively low degree of human disturbances. The analyses were carried out considering two different scales (a reach of about 430 ha and a sub-reach of about 25 ha) and were based on two subsequent datasets in order to investigate the shortterm geomorphic changes due to eight significant floods. The surveys were performed using two different datasets derived from LiDAR and TLS technologies and used to analyze the reach and sub-reach respectively. The short-term estimates of geomorphic and volumetric changes were performed using DEMs of Difference (DoD) based on a Fuzzy Inference System. The results have confirmed the high dynamism of the Tagliamento river, estimating a prevalent deposition at reach and a predominant erosion at sub-reach levels. Finally, a comparative qualitative assessment of the output derived from the different data sources was performed, showing little differences between the two survey methods that proved to be both precise and reliable.

Morphological Changes in the Brain of Acutely Ill and Weight-Recovered Patients with Anorexia Nervosa

2014 ◽  
Vol 42 (1) ◽  
pp. 7-18 ◽  
Author(s):  
Jochen Seitz ◽  
Katharina Bühren ◽  
Georg G. von Polier ◽  
Nicole Heussen ◽  
Beate Herpertz-Dahlmann ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Cognitive Deficits ◽  
Time Course ◽  
Morphological Changes ◽  
Meta Analysis ◽  
Short Term ◽  
Clinical Prognosis ◽  
Qualitative Review ◽  
Brain Changes ◽  
The Brain

Objective: Acute anorexia nervosa (AN) leads to reduced gray (GM) and white matter (WM) volume in the brain, which however improves again upon restoration of weight. Yet little is known about the extent and clinical correlates of these brain changes, nor do we know much about the time-course and completeness of their recovery. Methods: We conducted a meta-analysis and a qualitative review of all magnetic resonance imaging studies involving volume analyses of the brain in both acute and recovered AN. Results: We identified structural neuroimaging studies with a total of 214 acute AN patients and 177 weight-recovered AN patients. In acute AN, GM was reduced by 5.6% and WM by 3.8% compared to healthy controls (HC). Short-term weight recovery 2–5 months after admission resulted in restitution of about half of the GM aberrations and almost full WM recovery. After 2–8 years of remission GM and WM were nearly normalized, and differences to HC (GM: –1.0%, WM: –0.7%) were no longer significant, although small residual changes could not be ruled out. In the qualitative review some studies found GM volume loss to be associated with cognitive deficits and clinical prognosis. Conclusions: GM and WM were strongly reduced in acute AN. The completeness of brain volume rehabilitation remained equivocal.

INVESTIGATIONS OF THE BALTIC SEA COASTAL ZONE ABOVE-WATER PART TOPOGRAPHY DYNAMICS BY MEANS OF TERRESTRIAL LASER SCANNER (SVETLOGORSK CITY, KALININGRAD REGION)

2017 ◽  
Author(s):  
Nikolay Lugovoy ◽  
Nikolay Lugovoy ◽  
Askar Ilyasov ◽  
Askar Ilyasov ◽  
Elena Pronina ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Coastal Zone ◽  
Coastal Erosion ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
The Baltic Sea ◽  
Coastal Dynamics ◽  
Kaliningrad Region ◽  
The Baltic

The paper describes application of the terrestrial laser scanner for investigation of coastal dynamics of the Svetlogorskaya Bay, Baltic Sea. Methods of investigation and results of surveys repeated over the two consecutive years for quantification of coastal erosion and slope processes within the coastal zone are presented.

SHORT-TERM MORPHOLOGICAL CHANGES AND SEDIMENT DYNAMICS OF TIDAL FLAT DUE TO TYPHOON PASSAGE

2019 ◽  
Vol 75 (2) ◽  
pp. I_499-I_504
Author(s):  
Itsuki KURITANI ◽  
Shigeru KATO ◽  
Takahiro TABATA ◽  
Ryota NAKAMURA ◽  
Takumi OKABE
Keyword(s):  
Tidal Flat ◽  
Morphological Changes ◽  
Sediment Dynamics ◽  
Short Term

INSIGHTS FROM REPEATED TERRESTRIAL LASER-SCANNER SURVEYS OF CHANNEL-WALL EROSION ALONG THE SOUTH RIVER, VIRGINIA

2020 ◽  
Author(s):  
Collin Megee ◽  
◽  
Michael O'Neal ◽  
Joseph Clemens ◽  
Erica McMaster ◽  
...  
Keyword(s):  
Channel Wall ◽  
Laser Scanner ◽  
Terrestrial Laser Scanner ◽  
The South

scholarly journals Fitting Terrestrial Laser Scanner Point Clouds with T-Splines: Local Refinement Strategy for Rigid Body Motion

2021 ◽  
Vol 13 (13) ◽  
pp. 2494
Author(s):  
Gaël Kermarrec ◽  
Niklas Schild ◽  
Jan Hartmann
Keyword(s):  
Point Cloud ◽  
Goodness Of Fit ◽  
Laser Scanner ◽  
Point Clouds ◽  
Statistical Testing ◽  
Computational Time ◽  
Terrestrial Laser Scanner ◽  
Reference Surface ◽  
Local Refinement ◽  
Surface Approximation

T-splines have recently been introduced to represent objects of arbitrary shapes using a smaller number of control points than the conventional non-uniform rational B-splines (NURBS) or B-spline representatizons in computer-aided design, computer graphics and reverse engineering. They are flexible in representing complex surface shapes and economic in terms of parameters as they enable local refinement. This property is a great advantage when dense, scattered and noisy point clouds are approximated using least squares fitting, such as those from a terrestrial laser scanner (TLS). Unfortunately, when it comes to assessing the goodness of fit of the surface approximation with a real dataset, only a noisy point cloud can be approximated: (i) a low root mean squared error (RMSE) can be linked with an overfitting, i.e., a fitting of the noise, and should be correspondingly avoided, and (ii) a high RMSE is synonymous with a lack of details. To address the challenge of judging the approximation, the reference surface should be entirely known: this can be solved by printing a mathematically defined T-splines reference surface in three dimensions (3D) and modeling the artefacts induced by the 3D printing. Once scanned under different configurations, it is possible to assess the goodness of fit of the approximation for a noisy and potentially gappy point cloud and compare it with the traditional but less flexible NURBS. The advantages of T-splines local refinement open the door for further applications within a geodetic context such as rigorous statistical testing of deformation. Two different scans from a slightly deformed object were approximated; we found that more than 40% of the computational time could be saved without affecting the goodness of fit of the surface approximation by using the same mesh for the two epochs.

scholarly journals Direct Assessment of Biomass Productivity in Short Rotation Forestry (SRF) with the Terrestrial Laser Scanner (TLS). Case of Study in NE Part of Romania (Preliminary Results)

2020 ◽  
Vol 3 (1) ◽  
pp. 93
Author(s):  
Iulian Constantin Dănilă
Keyword(s):  
Biomass Production ◽  
Laser Scanner ◽  
Biomass Productivity ◽  
Tree Height ◽  
Allometric Equations ◽  
Accurate Information ◽  
Terrestrial Laser Scanner ◽  
North East ◽  
Short Rotation ◽  
Destructive Methods

Short rotation forestry (SRF) provides an important supply of biomass for investors in this area. In the NE (North-East) part of Romania at the present time are installed over 800 Ha of this kind of crops. The SRF enjoys the support through environmental policies, in relation to climate change and the provisions of the Kyoto Protocol to reduce the concentration of CO2 in the atmosphere. A precise estimate of biomass production is necessary for the sustainable planning of forest resources and for the exchange of energy in ecosystems. The use of the terrestrial laser scanner (TLS) in estimating the production of above ground wood biomass (AGWB) of short rotation forestry (SRF) brings an important technological leap among indirect (non-destructive) methods. TLS technology is justified when destructive methods become difficult to implement, and allometric equations do not provide accurate information. The main purpose of the research is to estimate the biomass productivity on tree parts in short rotation forestry with TLS technology. Measuring the hybrid poplars crops by TLS may have the following consequences: (1) Higher accuracy of the estimate of biomass production in the SRF; (2) cost and time effective measurements over the biomass of tree parts; (3) new and validated allometric equations for SRF in NE Romania; (4) solid instrument for industry to estimate biomass. TLS technology gives accurate estimates for DBH, tree height and location, as much as the volume on segments, commercial volume or crown volume can be determined. The accuracy of these values depends on the original scan data and their co-registration. The research will contribute to the development of knowledge in the field of hybrid crops.

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