Geomorphological Research Articles

Evaluating river morphology change with a geomorphic form variation approach

AbstractGeomorphic river design strives for natural resilience by encouraging geomorphic form complexity and morphological processes linked to greater habitat diversity. Increasing availability of high‐resolution topographic data and spatial feature mapping methods provide advantages for morphological analysis and river restoration planning. We propose and evaluate an approach to quantifying topographic variability of geomorphic form and pixel‐level surface roughness resulting from channel planform geometry differences using spatially continuous variety computation applied to component metrics including flow direction, aspect and planform curvature. We define this as the geomorphic form variation (GFV) approach and found it scalable, repeatable and a multi‐stage analytical metric for quantifying physical aspects of river‐bed topographic variability. GFV may complement process‐based morphological feature mapping applications, hydraulic assessment indices and spatial habitat heterogeneity metrics commonly used for ecological quality evaluation and river restoration. The GFV was tested on controlled synthetic channels derived from River Builder software and quasi‐controlled sinuous planform flume experiment channels. Component variety metrics respond independently to specific geometric surface changes and are sensitive to multi‐scaled morphology change, including coarser‐grained sediment distributions of pixel‐level surface roughness. GFV showed systematic patterns of change related to the effects of channel geometry, vertical bed feature (pool‐bar) frequency and amplitude, and bar size, shape and orientation. Hotspot analysis found that bar margins were major components of topographic complexity, whereas grain‐scale variety class maps further supported the multi‐stage analytical capability and scalability of the GFV approach. The GFV can provide an overall variety value that may support river restoration decision‐making and planning, particularly when geomorphic complexity enhancement is a design objective. Analysing metric variety values with statistically significant hotspot cluster maps and complementary process‐based software and mapping applications allows variety correspondence to systematic feature changes to be assessed, providing an analytical approach for river morphology change comparison, channel design and geomorphic process restoration.

The geomorphology of Ireland’s continental shelf

ABSTRACT The Irish Shelf Seabed Geomorphological Map (ISSGM) (v2023) presented here, is the first high-resolution geomorphological map of the entire Irish continental shelf. This large-scale mapping exercise took advantage of the vast INFOMAR multibeam echosounder dataset, and used a protocol of semi-automated mapping techniques to accurately and rapidly extract seabed features. All previous mapping efforts and existing literature on the Irish shallow shelf geomorphology have also been collated and integrated in the map, critically evaluating the previous interpretations. An internationally standardised classification scheme was adopted, aligning the ISSGM (v2023) to other international geomorphological work. At a national level, this detailed geomorphological digital map is intended primarily as a resource to better inform multiple offshore activities and management of the marine environment. The map also acts as a baseline for future studies in marine geomorphology, as it identifies gaps in the knowledge and highlights areas of contentious interpretation that require further work. The map is available online on the Irish Marine Atlas (https://atlas.marine.ie – Geology Theme).

Geospatial Tool-Based Geomorphological Mapping of The Lower Kulsi Basin, India

Detailed geomorphological map of a region provides necessary information on landforms to understand the variations of surface and subsurface processes. Geomorphological maps prepared based on a combined geospatial and field-observation approach are preliminary data for precise, prompt, and efficient watershed-level planning. The Kulsi is a significant left-bank tributary of the Brahmaputra. It has potential for agricultural, land, and water resources, but the region needs to catch up due to frequent climatic-geomorphic hazards. Therefore, this article aims to prepare an object-oriented detailed geomorphological map using geospatial tools. High-resolution satellite images and a digital elevation model were used to generate the detailed geomorphological map of the studied area. The resultant map is verified with extensive fieldwork. The investigated basin is characterized by structural and denudation hills, anthropogenetic escarpment; pediment plain, older and young alluvial plain; active and older flood plain; islands and sandbar deposits, and highly sinuous river and natural and artificial surface waterbodies. The research can contribute to local governments' and communities' land and water resource development plans. Keywords: geomorphology, morphometry, satellite image, Geographic Information System

Host-sensitized colour-tunable emission and Judd-ofelt analysis for Dy3+-doped ZnGa2O4 phosphor through exciton-mediated energy transfer

Single-phase Dy3+-doped zinc gallate (ZnGa2O4) phosphors were synthesized using a conventional solid-state fabrication technique. The structural properties of the host phosphor were determined through X-ray powder diffraction (XRPD) and Rietveld refinement, revealing a cubic spinal structure with a space group of Fd3m. The reflectance properties of the host and doped samples were measured using UV–Vis spectroscopy. The obtained data were used to estimate the bandgap of all the synthesized samples, ranging from 4.18 to 3.69 eV, confirming the formation of a wide bandgap semiconductor. Morphological, compositional, and surface mapping analyses were conducted using a field emission scanning electron microscope, energy dispersive electron spectroscopy, and time-of-flight secondary ion mass spectroscopy. X-ray photoelectron spectroscopy was employed to confirm the oxidation state of the constituent elements and for an in-depth study of the crystal structure. Photoluminescence excitation and emission spectra were recorded to analyze the luminescent properties of the synthesized phosphors. It was confirmed that when using an excitation wavelength of 247 nm, all samples exhibited broad host emission with decreasing intensity. In contrast, Dy3+ emission displayed an increasing trend, confirming host sensitization in this phosphor. To analyze the radiative properties of the activator ion, theoretical analysis using the Judd-Ofelt theory was carried out. The results revealed an overlapping of orbitals between the O2− ion and Dy3+, indicating its higher-order covalent nature and the increased symmetric nature of the activator ion in the present host. This characteristic allowed for the generation of near-white light emissions. A concentration of 7 mol% of Dy3+ was observed to match well with achromatic white (0.32, 0.33) on the color chromaticity diagram. The luminous properties of this material suggest that it is a desirable candidate for use in LEDs and AC electroluminescent systems.

Reconstructing basal ice flow patterns of the Last Glacial Maximum Rhine glacier (northern Alpine foreland) based on streamlined subglacial landforms

AbstractBased on high‐resolution (sub)glacial geomorphological mapping, we present a first digital inventory of streamlined bedforms within the footprint of a Last Glacial Maximum (LGM) Alpine piedmont glacier. A total of 2460 drumlins were mapped across the Rhine glacier foreland. Glacial lineations and one field of subglacial ribs (ribbed/Rogen moraines) — the first record of this type of subglacial landform on the Alpine foreland—were identified. Two flowsets, associated with (i) the Rhine glacier's LGM maximum advance (Schaffhausen stadial) and (ii) a late LGM readvance (Stein am Rhein stadial), are differentiated. The vast majority of streamlined bedforms occur in fields aligned in a 16‐ to 30‐km‐wide swath upstream of the Stein am Rhein frontal moraines. Orientation and elongation of drumlins and glacial lineations set the basis for the reconstruction of paleo‐ice flow. Basal flow paths of the LGM maximum advance are visually interpreted and restricted to the zone proximal to the former ice front. The flow field reconstructed for the late LGM glacier readvance (Stein am Rhein stadial) extends tens of kilometres upstream and is modelled implementing a recently published kriging routine. The derived basal flow patterns paired with information on ice surface levels from lateral and frontal moraines and combined with relative ice velocity differences inferred from spatial changes in bedform elongation reveal detailed insights on ice flow geometries, particularly during the glacier readvance. Reconstructed flowlines highlight basal flow under shallow ice that is strongly controlled by local topography evidenced by diverging around basal bumps and converging in (narrow) valley sections and troughs, where basal flow velocities, steered by topography, are high. Gained paleo‐ice basal flow patterns offer new insights on landscape evolution of the northern Alpine foreland and provide evidence‐based flow data to validate future physical modelling results.

A triangulation approach for groundwater potential evaluation using geospatial technology and multi-criteria decision analysis (MCDA) in Edo State, Nigeria

The quality and availability of groundwater resources are under extreme pressure as a result of growing urbanisation and population. The creation of lithological, structural, and geomorphological maps is made easier by satellite-based remote sensing data, notably at a regional level. This study uses the analytical hierarchical process (AHP) and geoinformatics-based approaches to facilitate and analyse different layers of geographically influencing data to define groundwater potential zones (GWPZ) in Edo State, Nigeria. The generated GWPZ map was created by selecting and weighting eleven precisely defined variables (including rainfall, lineament density, geomorphology, slopes, drainage density, soil type, landuse/landcover, proximity to surface water bodies, geology, a digital elevation model, and land surface temperature) based on their effect on groundwater availability. The zones of groundwater potential were developed using a GIS that incorporated the regulating variables. Depending on the degree of groundwater accessibility within each, this was grouped into four classifications (high, moderate, low, and very low). Low to moderate levels were seen across the study area, with high GWPZ representing 18% (3135.0294 km2) of the total area but only found in the Edo-central and isolated portions of the Edo-south. However, a very small fraction (3%) of very low GWPZ was found in the study's northern region. The exactitude of the established GWPZ map was determined to be 81.25% utilising well yield data (m3/d) from sixteen strategically selected boreholes in the study location, which were used to validate the GWPZ map. The research has shown that the criteria that have been observed are what govern the asymmetric distribution of these groundwater potential zones. The study will aid in the creation and governance of groundwater sources by improving recharge techniques, particularly in very low and low groundwater potential zones.

Reconstruction of palaeoglaciers and palaeoclimate in Zheduo Shan, Eastern Tibetan Plateau, during the Last Glacial Maximum

Reconstructing the extent and timing of palaeoglaciers and their associated climate is of great importance for understanding the responses of glaciers to climate change. Glacial landforms are well-preserved in Zheduo Shan, one of the high mountain ranges on the eastern Tibetan Plateau (TP). However, few studies have constrained glacial chronologies and estimated palaeoclimate in this area. We investigated the glacial advance during the Last Glacial Maximum (LGM) in Zheduo Shan using 10Be surface exposure dating. We then reconstructed the extent and thickness of LGM glaciers based on geomorphological mapping and a flowline-based glacial model-PalaeoIce. Eleven 10Be exposure ages confirmed a major LGM glacial advance between 20.0 ± 3.2 ka and 19.3 ± 2.8 ka. The reconstructed LGM glaciers in this mountain range covered an area of 499.16 km2 with an average ice thickness of 54.4 m and a total ice volume of 52.82 km3. The regional average equilibrium-line altitude (ELA) was estimated as 4524 ± 140 m, 535 ± 140 m lower than the present value. Based on the empirical relationship between precipitation and temperature (P-T model) at the ELAs on the TP, the temperature and precipitation were estimated as 3.10–5.27 °C and 10–16% lower during the LGM than the present values, respectively. These results suggest that the LGM glacial advance was more sensitive to temperature than precipitation in Zheduo Shan.

High-resolution optical remote sensing geomorphological mapping of coral reef: Supporting conservation and management of marine protected áreas

Brazilian corals are unique ecosystems with high endemism and low functional redundancy. Hence, mapping its geomorphology is an important step to inferring analyzes on benthic habitats. We observe several difficulties during this mapping of coastal areas by remote sensing and a lack of fine-scale depth data for reef areas in Brazil. The present study aims to present the bathymetry extracted by satellite imagery in murky waters using a mosaic of Sentinel-2 images in Google Earth Engine (GEE) calibrated with field samples. We used the satellite extracted DBM to map the bottom geomorphology through BTM (Benthic Terrain Modeler). We then present the first detailed geomorphological map for the largest marine coastal protected area in Brazil- MPA Costa dos Corais. The geomorphological raster was differentiated into seven classes: Flat Plains, Depressions, Gentle Slopes, Slopes, Terrestrial Reef Flat, Reef Flat, and Crest. Altogether, we estimate >275 km2 of area representing reef structures (coral reef or beachrocks), or about 48% of the total MPA area. Mapping coral reefs can contribute to conservation, particularly in selecting areas for in situ monitoring activities and in prioritizing the application of remedial actions in the event of environmental disasters or threats to coral health, such as oil spills and bleaching episodes. Our findings encourage the applicability of these methodologies in other reef areas and collaborate for the management and monitoring of marine protected areas. In addition, all mapping is available online for any user.

First record of theridiosomatid genus Sennin Suzuki, Hiramatsu & Tatsuta, 2022 from Anhui Province, China, with the description of a new species (Araneae, Theridiosomatidiae).

Only two Sennin species are known from the world, Sennincoddingtoni (Zhu, Zhang & Chen, 2001) from China and Sennintanikawai Suzuki, Hiramatsu & Tatsuta, 2022 from Ryukyu Islands. No other Sennin species have been recorded from other locations. A new species, Senninshuanglong sp. n. is described from Anhui Province, China. Morphological illustrations, SEMs, living photos, habitat and distribution map are given.

Geomorphological regional mapping for environmental planning in developing countries

Developing countries usually lack environmental baseline information for territorial decision-making. Geomorphological maps constitute valuable tools for natural resource management due to the landforms permanence and dynamics creating interactions between biotic, abiotic, and anthropic unique characteristics worldwide. In this paper, we present an updated method to perform geomorphological regional units applied for developing countries. This region is highly populated and face particular and more challenging development issues. We used the Southern Pacific, or the Brunca region of Costa Rica, as a study site to apply the geomorphological regional unit approach. Our results show that this territory presents mountainous, volcanic, fluvial, and coastal landforms with a vast variety of soils, life zones, protected areas, and land uses in a culturally rich region. Moreover, we discuss and make proposals for land use planning implications, disaster risk conditions, and the ecological and tourism prospects of the region. This approach can be widely used in developing countries throughout the world for their territorial environmental assessment.

Accuracy assessment of post‐processing kinematic georeferencing based on uncrewed aerial vehicle‐based structures from motion multi‐view stereo photogrammetry

AbstractWe verified a method of acquiring digital surface models of steep, forested, small watershed topography, where real‐time kinematic processing is difficult because of the presence of interfering objects. Our approach involved using an uncrewed aerial vehicle with a built‐in global navigation satellite system, which reduces time and labour costs. We tested the applicability of structure‐from‐motion multi‐view stereo processing, and post‐processing motion corrections of positional coordinate data were also tested. Nine verification points were established in a small 0.5 km2 watershed, with check dams established in the headwaters of the forested area. The position accuracy and overall working time of verification points extracted by the method were compared with the position accuracy and work time obtained by a field survey using a conventional total station. The results show that the vertical error between the total station and each verification point at an altitude of 150 m ranged from 0.006 to 0.181 m. The working time of the survey was 13% of that of the total station survey. The proposed workflow shows that safe and non‐destructive topographic surveying, including fluvial geomorphological mapping, is possible with a vertical error of ±0.103 m in small watersheds. This method will be useful for rapid topographic surveying in inaccessible areas during disasters, namely, debris flow monitoring at check dam sites and efficient topographic mapping of steep valleys in forested areas where positioning ground control points is laborious. It should also be of widespread interest to geographers working with spatial challenges related to land management.

Hierarchical Self-Assembly of Carbon Dots into High-Aspect-Ratio Nanowires.

We report a spontaneous and hierarchical self-assembly mechanism of carbon dots prepared from citric acid and urea into nanowire structures with large aspect ratios (>50). Scattering-type scanning near-field optical microscopy (s-SNOM) with broadly tunable mid-IR excitation was used to interrogate details of the self-assembly process by generating nanoscopic chemical maps of local wire morphology and composition. s-SNOM images capture the evolution of wire formation and the complex interplay between different chemical constituents directing assembly over the nano- to microscopic length scales. We propose that residual citrate promotes tautomerization of melamine surface functionalities to produce supramolecular shape synthons comprised of melamine-cyanurate adducts capable of forming long-range and highly directional hydrogen-bonding networks. This intrinsic, heterogeneity-driven self-assembly mechanism reflects synergistic combinations of high chemical specificity and long-range cooperativity that may be harnessed to reproducibly fabricate functional structures on arbitrary surfaces.

Death of a palaeochannel: Slow abandonment of an avulsed channel on the Riverine Plains, SE Australia

AbstractAvulsion of rivers can be a gradual process that is associated with a metamorphosis of channel pattern or changed channel characteristics. The processes controlling avulsion, and hence anastomosis, often operate too slowly to study by measuring active river systems, and hence well preserved Late Quaternary rivers offer one of the best ways to study the long‐term development of avulsive systems. The modern and ancient channels of the Murrumbidgee River provide a classic example of long‐lived, semi‐static anastomosis, operating on timescales that include stadial and interstadial climate cycles. Over the last glacial cycle, regional avulsions have occurred every ~12 ka while maintaining an anastomosing pattern through the slow infill of abandoned channels. The Yanco Creek Palaeochannel System emerged from a period of high discharge linked to snowmelt in the terminal Pleistocene. Here, geomorphological mapping of the Yanco System was conducted together with single‐grain, optically stimulated luminescence dating of sediments in the channel belt. Since the main phase of channel construction during the Last Glacial Maximum, the Yanco system has functioned as a flood conduit and minor anabranch of the Murrumbidgee River, with reworking of ancient channel sediments by an underfit stream that is ongoing to the present day. Our new ages of ~13–14 ka are interpreted as channel sedimentation during an underfit phase following avulsion. The prevalence of full and partial avulsion in this environment may be complicating palaeohydrological interpretations of ages for channel activity, and reworking has gone unrecognised. We contend that some previous interpretations of the significance of ages for sediments collected from palaeochannels in the Riverine Plain may need revision.

Seabed characterization of the Trindade island shelf, Brazil

This paper presents the first mapping of bedform morphological features on the Trindade Island shelf, with the goal of identifying and defining them.By using a side scan sonar, collecting seabed samples, and taking submarine photographs, five different morphological types were identified on this shelf: an erosive type: (i) characterized by the dispersion of rocks and rock blocks; and four depositional types: (ii) one formed by calcareous algal reefs, (iii) one composed by rhodoliths, (iv) one formed by medium sands with large symmetrical wave ripples, (v) and the last one formed by fine sands with asymmetrical wave ripples. The main result is a morphological map of the Trindade Island shelf, which shows the occurrence of these five seabed units.To further understand the sedimentological factors that affect the island shelf, we also examined the sediments that were collected for this study. Our results show that the amount of carbonate-formed grains on the collected sand sediments is higher than the amount of grains formed by the volcanoclastic ones, generated by the disaggregation of the main building on Trindade Island. The sediments formed by bioclastic grains are more frequently found in the coarser fractions than in the finer fractions when compared to lithic ones.

Automatic identification and morphological comparison of bivalve and brachiopod fossils based on deep learning.

Fossil identification is an essential and fundamental task for conducting palaeontological research. Because the manual identification of fossils requires extensive experience and is time-consuming, automatic identification methods are proposed. However, these studies are limited to a few or dozens of species, which is hardly adequate for the needs of research. This study enabled the automatic identification of hundreds of species based on a newly established fossil dataset. An available "bivalve and brachiopod fossil image dataset" (BBFID, containing >16,000 "image-label" data pairs, taxonomic determination completed) was created. The bivalves and brachiopods contained in BBFID are closely related in morphology, ecology and evolution that have long attracted the interest of researchers. We achieved >80% identification accuracy at 22 genera and ∼64% accuracy at 343 species using EfficientNetV2s architecture. The intermediate output of the model was extracted and downscaled to obtain the morphological feature space of fossils using t-distributed stochastic neighbor embedding (t-SNE). We found a distinctive boundary between the morphological feature points of bivalves and brachiopods in fossil morphological feature distribution maps. This study provides a possible method for studying the morphological evolution of fossil clades using computer vision in the future.

Corrosion and bacterial growth inhibition by amino acid functionalized pyridine derivative at P110 steel/oil formation water interface: Experimental, surface and molecular docking investigations

The prime objective of the present research is to explore the green synthesis of pyridine derivative by functionalizing amino acid vanillin (Py-Va) using the ultrasound method and its application as a novel corrosion inhibitor for P110 steel in oil formation water (OFW). The results report that Py-Va inhibits P110 steel corrosion and represents a significant decrease in corrosion rate with the rising dose at certain temperatures. Electrochemical experiments manifest that Py-Va can restrain reactions of the cathode and anode of P110 steel. The molecular adsorption of Py-Va is governed by Langmuir isotherm with the chemical mechanism participation. The morphology maps of surface analysis support the creation of an inhibitive layer of Py-Va over the steel surface. Biological activity reveals a significant reduction in the sulfate-reducing bacteria (SRB) after Py-Va addition. Molecular docking and Root Mean Square deviation (RMSD) as used to analyze the Py-Va and SRB protein interaction.

Study of short-term corrosion behavior of Q345 steel in marine atmospheric environment

This work studied the corrosion behavior law of Q345 steel exposed to 120 days in Qingdao marine atmospheric environment and the differences in corrosion behavior between the sunlit and shaded sides. The corrosion behavior law of Q345 steel was studied in detail by using weight loss method, electrochemical test, SEM, XRD and ultra-depth microscope. We found that the weight loss curve of Q345 steel under short exposure time still conforms to the power function form, and the corrosion rate increases in the early stage (15 d, 30 d) and decreases in the later stage. The change trend of polarization resistance (Rp) and corrosion current density (Icorr) obtained by electrochemical test corresponds to it. There are significant differences in the morphology and phase composition of the corrosion products of Q345 steel sunlit and shaded sides. On the one hand, the color of the rust layer is not the same, and the rust layer of the shaded side is loose and easy to fall off, and the corrosion is more serious. The three-dimensional morphology map after rust removal showed that Q345 steel had obvious local corrosion in the early stage of corrosion, and the depth of the corrosion pit on the shaded side was greater than that on the sunlit side. On the other hand, the ratio of (β + s)/γ * on the shaded side was greater than that on the sunlit side, and the protection ability of the rust layer on the shaded side was weak. The corrosion characteristics of Q345 steel are different between the sunlit side and the shaded side, and the corrosion of the shaded side is more serious. In engineering applications, we should consider the consequences of this phenomenon.

Glacial geomorphology of the Notsarula and Chanchakhi river valleys, Georgian Caucasus

ABSTRACT Detailed glacial geomorphological maps are valuable for identifying target sites for palaeoglaciological reconstructions and thus for palaeoclimate inferences. In this study, we present the first detailed glacial geomorphological mapping of the landform assemblages produced by the former glaciers in the Notsarula (42°45′44″N 43°38′29″E) and Chanchakhi (42°42′5″N 43°40′42″E) river valleys, Georgian Caucasus. Our goal is to create a high-resolution (1:33,000 scale) glacial geomorphological map of this area (237 km2) and provide a detailed and accurate distribution of glacier-related features (see Main Map). Several field investigations between 2010 and 2022 along with detailed remote sensing surveys have been conducted for this glacial geomorphological mapping. The mapped landforms indicate multiple readvance or stillstands of valley glaciers across the study area. The largest and complex glacier body likely existed in the Bubistskali River gorge (42°43′16″N 43°43′32″E). Well-preserved moraine landforms in this valley suggest at least five large and several relatively small glacier readvances or stillstands occurred during the Late Quaternary. The simple-valley-type (without branches) glaciers were also probably present in other tributary valleys of the Chanchakhi River basin at that time. This map can be used for further geomorphological investigation as well as to support future geochronological work in the Greater Caucasus.

Origin and post‐glacial evolution of surface cracks: A case study from the area of the Last Glaciation, north‐eastern Poland

AbstractThe analysis of LiDAR‐based digital elevation models revealed the existence of groups of longitudinal fractures in the ground in northern Poland at the limit of the ice sheet's extent during its last maximum. Our research on the closed elongated depressions (CEDs) of the Jedwabno test field (Szuć site, north‐east Poland) focuses on explaining their origins and their post‐glacial history. This region was covered by an ice sheet and glacitectonically active during the Vistulian, and at least some surface fractures are possible witnesses to this activity. Using geomorphological mapping, sedimentological and geophysical research, we assumed it was related that the origin of these features here is associated with groundwater migration at the end of the Vistulian glaciation or later when groundwater flow intensified due to a rapid climate warming that caused permafrost to melt. The thawing of permafrost caused to transition from continuous permafrost to discontinuous, which in turn created groundwater flow that was probably responsible for the development of the surface cracks (fractures). Radiocarbon, palaeobiological (pollen, Cladocera) and geochemical studies allowed for an estimation of the formation time of these unique surface cracks in the Older Dryas. Prevailing conditions were also reconstructed for the later dynamic changes of the end of the Late Vistulian glaciation and in the Late Holocene until the Subatlantic Period (Megalayan stage). The surface cracks with steep slopes, despite their small area, are extraordinary sedimentation traps that have, in a special way, retained an almost complete record of the environmental and climate changes of the Late Glacial. There are sedimentological gaps in the Holocene, especially after the Preboreal (old part of the Greenlandian Stage), caused by changes in water levels, aeolian processes and human activity.

Sedimentary texture of crevasse splays formed by present-day and palaeofloods against the background of floodplain geomorphology and lithofacies exposed in channel cut banks (in the Vistula River valley between Warsaw and Płock, Poland)

Abstract On the floodplain of a sandy, braided river in the Central European Lowland, we studied the sedimentary texture of two crevasse splays, which were: (1) formed due to a levee breach in the 2010 flood, and widely documented by hydrological, bathymetric and LIDAR data, (2) developed under natural conditions when the channel was not embanked by artificial levees (dikes). We compare the sedimentological results with a geomorphological map, a model of the floodplain geomorphology showing different facies of fluvial deposition derived from a meandering river, and deposits in cut banks of the river channel. The statistical parameters of the grain size composition and geomorphic features of the splay, shaped by overbank flow through the broken embankment, are similar to the natural landform. Most of the cut banks (60% of alluvial deposits were mapped there) consist of lithofacies representing proximal floodplain; 30% were distal floodplain (muds), and 10% channel (coarse sand with gravel, pebbles and cobbles). We speculate about the palaeogeography of the Lower Vistula, and the origin of muds and coarse deposits in the banks of the channel. We link these unusual sediments with avulsion, deposition in side arms during ice-jam conditions, and dredging of the channel bottom by suction excavator, which reached the fluvioglacial, suballuvial layer on the bedrock protrusion.