Composite methodology for interpreting sediment transport pathways from spatial trends in grain size: A case study of the Lithuanian coast

Abstract

To achieve a more robust interpretation of sediment conditions and transport based on grain size, this study combines the perspectives of two different interpretation techniques that have been developed separately and applied in the literature: (i) ‘grain size trend analysis’ interprets changes between interrelated sampling sites assuming that sediment in the direction of transport should become either coarser, better sorted and more positively skewed, or finer, better sorted and more negatively skewed; and (ii) the ‘population anomalies’ method, which estimates the balance between erosion and accumulation processes at each sampling site based on individual site deviations compared with average values for grain‐size parameters in the area of interest. The simultaneous use of both approaches enables sedimentological conditions and transport alternatives to be distinguished. This improvement is necessary because site‐specific changes and general textural trends provide information that complements the strengths and weaknesses of each perspective. The methods are implemented here using two‐dimensional Geographic Information System tools and illustrated for the Lithuanian coast. Grain‐size characteristics of 712 surface samples of sandy sediments are used to interpret sediment transport pathways and predominant sedimentological conditions in the Lithuanian coastal zone. In general, coast‐parallel sediment transport dominates the entire investigation area, although wave‐induced movement perpendicular to the coastline is inferred in the shallow nearshore zone. The deepest areas offshore are characterized by sea floor erosion in the north, whereas an accumulation zone occurs in the relatively deep central part of the study area.

The influence of natural and anthropogenic factors on grain size distribution along the southeastern Baltic spits

“…These meth ods have been widely used to de ter mine sed i ment trans port in differ ent sed i men tary en vi ron ments and are in agree ment with direct mea sure ments of pro cesses and nu mer i cal mod el ling results (Mal let et al, 2000;Rios et al, 2002;van Lancker et al, 2004;Hequette et al, 2008;Maillet et al, 2011;Poizot et al, 2013). Sed i ment trend anal y sis meth ods (Mc Laren and Bowles, 1985;Gao and Col lins, 1992) were used to de ter mine pat terns of the long shore and cross-shore sed i ment trans port in the Polish, Lith u a nian and Rus sian nearshore zone of the Bal tic Sea by Baraniecki and Racinowski (1996), KairytÅ and Stevens (2015) and Kovaleva et al (2016). How ever, when ap ply ing the above-men tioned meth ods for the de ter mi na tion of sed i ment trans port vec tors, re search ers of ten come across un ex pected cir cum stances, e.g.…”

Sediment Classification using Envirometric Technique: A Study Case in Pahang River, Malaysia

“…Nilai pencongan bagi suatu sampel berkait rapat dengan bahan mendapan terdapat di dalam sungai. Sebahagian pasir sungai menunjukkan pencongan positif kerana kebanyakan butiran halus yang dimendapkan selepas sungai surut akibat banjir atau hujan, manakala pasir pantai menunjukkan pencongan negatif kerana butiran kasar akan mudah diasingkan oleh pergerakan arus [18]. Bahan enapan bagi kawasan tebing kanan Sungai Pahang adalah berkeadaaan negatif iaitu butiran yang kasar yang mana kawasan tersebut akan mudah mengalami proses hakisan dan pengangkutan serta lebih mudah mengalami perubahan bentuk dan plan sungai.…”

“…Jadual 4 dan Rajah 5 menunjukkan hasil yang diperolehi selepas analisis pengelasan dijalankan. [12,18]. Selepas membuat pengelasan, didapati bahagian tebing kanan sungai didominasi oleh tahap keseragaman yang buruk dengan nilai phi 1.0 ke phi 2.0 iaitu pada stesen 3, 4, 5 ,6, 8, 10, 12 dan 13, sederhana baik dengan nilai phi 0.5 ke phi 0.71 di stesen 7, 9 dan 12 dan tahap sederhana terdapat di stesen 1 dan 2 dengan nilai phi 0.71 ke phi 1.0.…”

Assessment of the Influence of Dredge Spoil Dumping on the Seafloor Geological Integrity

“…Findings from the study are used for producing a graphical illustration of the assessment process. Grain-size data have been successfully used previously for inferring sediment sources and depositional sub-environments (e.g., Folk and Ward, 1957;Stevens et al, 1996;Bobertz and Harff, 2004;Kairyte and Stevens, 2015), as well as anthropogenic influence such as the redistribution of dumped dredge spoil on the seafloor (Okada et al, 2009;McLaren and Teear, 2014). This study focuses on two offshore dumping areas in Finland, Vuosaari in the south coast and Uusikaupunki-D in the west coast (Figures 1, 2), which provide test cases for discriminating dumped dredge spoil and naturally deposited sediments.…”