Sediment grain size estimation using airborne remote sensing, field sampling, and robust statistic

2011 ◽  
Vol 181 (1-4) ◽  
pp. 431-444 ◽  
Author(s):  
Elena Castillo ◽  
Raúl Pereda ◽  
Julio Manuel de Luis ◽  
Raúl Medina ◽  
Javier Viguri
2021 ◽  
Author(s):  
Vilmos Steinmann ◽  
Ákos Kereszturi

<p>Most of the Martian fluvial valleys formed in the early period (around the Noachian-Hesperian boundary or before), but the formation durations are not well determined, however it would be important to understand as it is related to the climatic history and the reason for specific morphology of the Red Planet’s valleys. We estimated the formation duration for a hundred different sections of a small (~81 km long) Martian valley (called Tinto B, which is East of Palos crater and Tinro Vallis), using ArcMap and Excel software. We used the HRSC DTM (Digital Terrain Model), which was resampled from the resolution of 50 m/px to 100 m/px, because the used THEMIS TI dataset (used for grain size estimation) has a 100 m/px resolution. The visual morphological analysis we used the CTX images.  For the calculation we considered the cross-sectional profile of the valley as a trapezoid shape and calculated the hydraulic radius for it and used several hydraulic variables, like average flow velocity, bedload transport rate, sediment and flow discharge [1], slope of energy grade line. For the formation timescale calculation the Meyer-Peter and Muller bedload transport equation [2] was used. For the sediment grain size estimation we used the THEMIS TI dataset and calculated the shear stress and the Shield parameter from it [3]. The bed of the valley is covered with aeolic sand, which does not represent the grain size of the eroded bedrock, which probably took part in the original formation process. For this reason we sampled the grain size from exposures on both sides of the valley walls, where the original bedrock represented to the best approximation and continuously. The main aim of the work is to compare the different sections of the analysed valley by the final assumed age and different variables and morphology. The detailed morphology analísation comes from the previously made erosion-accumulation results [4] and the visual analysis of the valley. From the given section results the median formation time scale of the valley can be calculated also. With this method the Martian valleys can be comparable with the terrestrial mars-analog valleys after the same calculations. The estimated formation timescale of the whole valley will be compared with the result of the crater size frequency distribution based statistically estimated age of the valley bed. </p> <p> </p> <p>References:</p> <p>[1] - M. R.T. Hoke, B. M. Hynek, G. E. Tucker, Formation timescales of large Martian valley networks, Earth and Planetary Science Letters, 2011, Volume 312, Issues 1–2</p> <p>[2] - M. Wong, G. Parker, Reanalysis and correction of bed-load relation of Meyer-Peter and Muller using their own database, J. Hyrdaul. Eng, 2006, pp. 1159-1168</p> <p>[3] - L. K. Fenton, J. L. Bandfield, A. W. Ward, Aeolian process on Mars: atmospheric modeling and GIS analysis, Journal of Geophysical Research, 2003</p> <p>[4] - V. Steinmann, Á. Kereszturi, L. Mari, Geomorphological analysis of Tinto-B Vallis on Mars, Hungarian Geographical Bulletin, 2020, pp 333-348</p>


2009 ◽  
Vol 67 (3) ◽  
pp. 594-605 ◽  
Author(s):  
Victor Quintino ◽  
Rosa Freitas ◽  
Renato Mamede ◽  
Fernando Ricardo ◽  
Ana Maria Rodrigues ◽  
...  

Abstract Quintino, V., Freitas, R., Mamede, R., Ricardo, F., Rodrigues, A. M., Mota, J., Pérez-Ruzafa, Á., and Marcos, C. 2010. Remote sensing of underwater vegetation using single-beam acoustics. – ICES Journal of Marine Science, 67: 594–605. A single-beam, acoustic, ground-discrimination system (QTC VIEW, Series V) was used to study the distribution of underwater macrophytes in a shallow-water coastal system, employing frequencies of 50 and 200 kHz. The study was conducted in Mar Menor, SE Spain, where the expansion of Caulerpa prolifera has contributed to the silting up of the superficial sediments. A direct relationship was identified between algal biomass and sediment-fines content. Acoustic information on sediment grain size and data on algal biomass were obtained in muddy and sandy sediments, including vegetated and non-vegetated seabed. Non-vegetated muddy areas were created by diving and handpicking the algae. The multivariate acoustic data were analysed under the null hypotheses that there were no acoustic differences between bare seabeds with contrasting superficial sediment types or among low, medium, and high algal-biomass areas, having in mind that grain size can act as a confounding factor. Both null hypotheses were rejected, and the results showed that 200 kHz was better than 50 kHz in distinguishing cover levels of algal biomass. The relationship between the 200-kHz acoustic data and algal biomass suggests utility in modelling the latter using the former.


2021 ◽  
Author(s):  
Adrian Bender

Expanded methods for discharge and grain size estimation; access information for digital imagery and elevation data; precipitation and discharge data; and field data collected during this study.


2001 ◽  
Vol 46 (2-3) ◽  
pp. 113-118 ◽  
Author(s):  
I. Saxl ◽  
P. Ponı́z̆il

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