Holocene Evolution of Deltas

Fluvial lowlands have become attractive human settling areas all around the world over the last few millennia. Because rivers kept changing their course and networks due to avulsion, the sedimentary sequences in these areas are archives of both fluvial geomorphological and archaeological development. We integrated geological and archaeological datasets to demonstrate the concurrence of the gradual abandonment of a major Rhine channel (Utrecht, The Netherlands), the development of human habitation in the area, and the interactions between them.

The Utrecht case study highlights the stage-wise abandonment of a natural river channel, due to avulsion, coincident with intensifying human occupation in Roman and Early Medieval times (1st millennium AD). The analyses make maximum use of very rich data sets available for the study area and the tight age control that the geo-archaeological dataset facilitates, offering extra means of time-control to document the pacing of the abandonment process. This allows us to quantify change in river dimensions and meander style and to provide discharge estimates for successive stages of the abandonment phase over a 1000-year period of abandonment succession, from mature river to eventual Late Medieval overbuilt canal when the Rhine branch had lost even more discharge.

Continued geomorphic development during this period - which includes the 'Dark Ages' (450-1000 AD) - appears to have been crucial in the development of Utrecht from Roman army fortress to Medieval ecclesial centre. The settlement dynamics in and around the city of Utrecht changed during the various phases of abandonment. In the bifurcating network of river branches forming the Rhine-Meuse delta, the main Rhine branch hosted the Roman limes military border and transport route. The Rhine- Vecht bifurcation at Utrecht provided an excellent location to raise a Roman fort. Continued geomorphic activity during abandonment in Early Medieval times was characterised by enhanced overbank sedimentation and shifts in the position of bifurcations. River flooding became more incidental in this stage, and alluvial-ridge occupancy became sensitive to flooding events for several centuries. We conclude by demonstrating that similar human-river interactions during Roman times occurred in several other deltas within the former Roman empire, with differences depending on the position of a settlement within the delta, the overall hydrological situation, and the ability of societies to control the changing environment.

This paper demonstrates the decisive role of natural preconditions on the formation of large late Holocene sea ingressions in peaty coastal plains along the North Sea's southern shores. Geological and archaeological evidence shows that these sea ingressions (expansion of new tidal systems) were mainly caused by land subsidence, which occurred due to intensified agricultural use of artificially drained peatlands since the Late Iron Age (250–12 BC). This made the coastal plain sensitive to storm-surge ingression through weak spots, e.g., at the location of existing creeks, in the coastline. Using The Netherlands as a case study, we show that natural preconditions (i.e., the geological setting at the time of ingression) played a key role in the pacing and extent of tidal area expansion. Ingressive tidal systems eventually reached most far inland in coastal segments with wide peaty back-barrier plains. In contrast, sea ingression formation was hampered in coastal segments with well-developed natural ingression-protecting geomorphic features (e.g., beach-barriers, supratidal levees). Feedback mechanisms , such as additional peat subsidence by loading of sediment imported into the new tidal area, caused further tidal volume increase and created accommodation space for tidal deposits. These combined effects caused irreversible sea ingression over large areas that consequently became unsuitable for habitation for many centuries. Improved understanding of such sea-ingression mechanisms and their facilitating conditions are essential for the assessment of the sensitivity of many densely populated coastal plains, which experience major human-induced subsidence, eventually leading to coastal plain drowning.

In 2011 a systematic underwater field survey and an invasive investigation were executed in the Yangtze Harbour planning area, Maasvlakte, Rotterdam, commissioned by Port of Rotterdam Authority.  The aim of the work was to locate and document any archaeological remains in submerged Late Pleistocene and Early Holocene deposits at a depth of 22m to 17m bsl, in the to-be-deepened and extended harbour. A drowned Lateglacial-Early Holocene floodplain  landscape was mapped and a Mesolithic site was discovered in it. The site was visited from c. 8500 to 6500 BC and became a nodal base camp 7000 to 6500 BC, when a wetland landscape had developed around it. Abundant flint tools, bones (of mammals, fish and bird) and plant material (pristine and charred) were recovered and provide information on mobility, diet and use of fire in the Middle Mesolithic. The site rapidly drowned in the transgressing North Sea owing to accelerated sea-level rise events of the period 6500-6300 BC. The site offers a window to the lowland archaeology of the Early Holocene in areas now offshore, that inland sites cannot off. The discoveries allow interregional comparison of delta habitation between the Middle Mesolithic (offshore, at depth in the sea, Doggerland) and Late Mesolithic (onshore, Rhine-Meuse delta, at depth below urbanized coastal plain).

Author list:
Boon, J.J., Brinkhuizen, D.C., Bunnik, F.P.M., Cohen, K.M., Cremer, H., Exaltus, R.P., van Kappel, K., Kooistra, L.I., Koolmees, H., de Kruyk, H., Kubiak-Martens, L., Moree, J.M., Niekus, M.J.L.T., Peeters, J.H.M., Schiltmans, D.E.A., Verbaas, A., Verbruggen, F., Vos, P.C., Zeiler, J.T.

Contents:
Chapter 1 Introduction
Chapter 2 Methods and techniques
Chapter 3 Landscape genesis and palaeogeography 
Chapter 4 Flint and other stone https://www.academia.edu/11573354/
Chapter 5 Fauna
Chapter 6 Archaeobotany: landscape reconstruction and plant food
Chapter 7 Synthesis  https://www.academia.edu/11600300/


Authorship is indicated per chapter. A rich DVD with further technical reports (in Dutch) is part of the publication. It also contains a 15 minute documentary movie (bilingual).

The book is the English translation of BOORrapporten 523 (2014, in Dutch, same editors and authors)
Link to DUTCH book: http://www.rotterdam.nl/Clusters/Stadsbeheer/Images%202014/BOOR/PDF/BOORrapporten%20523%20Rotterdam%20Yangtzehaven.pdf
Link to ENGLISH version: http://www.rotterdam.nl/Clusters/Stadsbeheer/Images%202015/BOOR/PDF/BR566_Maasvlakte2_ENGLISH.pdf
 
The PDF on the Rotterdam.nl website (the right link, in grey, below) is the full Book. It contains a PREFACE, a PART 2 on the stratigraphy of the sand extraction area off the Maasvlakte extension, and an EPILOGUE on a human bone find from that area). The PDF uploaded to academia.edu (the left link, in green, below) is PART 1 only.

During the mid-Holocene, some of the world's first large-scale complex societies came into being within the lower and middle reaches of a number of large river systems. Around this time, as global sea-level stabilised, the hosting fluvial environments of Lower Mesopotamia, the Nile Delta and the North China Plain were evolving from spatially varied landscapes dominated by swampy marshland, to better-drained, more uniform floodplain environments. It is necessary to consider whether such environmental changes could have guided aspects of sociocultural evolution in these settings.

In the Nile Delta, the setting for which most data are available, these palaeolandscape changes are comprehensively mapped through the construction of a four-dimensional aggradation model of the Holocene alluvial plain. Development of this model takes place within the context of a full reinterpretation of the Upper Quaternary stratigraphy of the Nile Delta, which is itself further informed by substantial programmes of fieldwork in the western delta. The environmental changes were forced by a decrease in the rate of relative sea-level rise within the context of decreased discharge and sediment-supply due to regional climate change.

A geoarchaeological model links these changes in the landscape to sociocultural developments taking place in Egypt between 5500 and 2500 BC. Increased adoption of agricultural practices in the delta was stimulated by a decrease in the primary productivity of the landscape, which then led to population growth and shifts in settlement styles. The emergence of the first Egyptian capital of Memphis at the delta apex can also be seen as having been facilitated by changes in the palaeogeography of the fluvio-deltaic environment. Such linkages between the changing deltaic landscapes and social change are crucial in understanding the formation of the Ancient Egyptian State (c. 3100 BC), which involved increased involvement of regional elites using the delta as both an agricultural resource and trade route.

In: R.C.G.M. Lauwerier, M.C. Eerden, B.J. Groenewoudt, M.A. Lascaris, E. Rensink, B.I. Smit, B.P. Speleers and J. van Doesburg (Eds.) 2017. Knowledge for Informed Choices. Tools for more effective and efficient selection of valuable archaeology in the Netherlands.  Nederlandse Archeologische Rapporten 55.

In a geological GIS-data recombination project, a digital map was produced that contains information on the Netherlands’ former coastal and delta plain landscapes over the last 14,000 years: the Holocene and the very end of the Pleistocene. The polygon map product is accompanied by a set of palaeoDEMs (Digital Elevation Models) indicating the attention depth for buried land surfaces and aquatic deposits for four time slices. This paper provides conceptual background information on the legend and construction principles behind the polygon maps and the palaeoDEMs, i.e. the decisions taken during the making of. It also provides a basic overview of the map product: landscape structure, burial depth and preservation, visualised for the four time slices in the RCE’s Archaeology Knowledge Kit. The text links coastal plain buried landscape mapping for four time slices to the other Knowledge Kit activities described in this volume, notably that of the Archaeological Landscapes map (for the most recent  time slice in the coastal plain area of the Netherlands, and for all time slices in the Pleistocene uplands).

The Danube delta is one of the few large deltas in the world the evolution of which has involved numerous and varied episodes within a complex framework of interactivity between river sediment supply, allochthonous sediments supplied by longshore currents, marine dispersing forces, vertical movements (neotectonics, sediment compaction) and sea level. The resulting complex morphology comprises diversified landscapes varying from labyrinthic net of channels and lakes (fluvial delta) to massive tracts of monotonous reed marshes, large lagoons divided by barriers, or beach-ridge plains accommodating large transgressive dunefields (maritime delta). Whilst previous studies have focused on various sectors of the Danube delta, the current paper proposes for the first time an integral reconstruction of delta evolution based on existing and new sedimentological and morphological analyses and absolute ages (AMS 14 C and OSL), enabling a comprehensive synthesis in terms of both evolutionary phases and growth patterns. A chronological framework was established for all the deltaic lobes and beach-ridge plains, highlighting the relationship between formation timespan, growth rates, and the resultant morphology. This work unveils the early stage of delta formation, including the reconstruction of delta front advancement into Danube Bay (Old Danube lobe: prior to 7.5–5.5 ka) and initial spit/barrier development (6.7/6.5–5.8 ka). Inception of the bayhead delta started > 1000 yr before the relative stabilization of sea level and of the initial spit formation. The original fluvial delta plain topography is now buried at a depth of 4–6 m depth below the present topography (representing the current stage of fluvial aggradation), as a result of subsidence and sea-level rise. Regarding the maritime delta, six large open-coast lobes developed in the last six millennia, of which four were formed by the Sf. Gheorghe branch, attesting the long uninterrupted activity of this branch, whereas the other two were created respectively by the Sulina and the Chilia branches. The evolution of each lobe is derived from successive (chronological) shoreline positions and discussed in relation with changes in Danube discharge. Special attention has been paid to their growth stages and progradation rates. For the southern delta, we bring in new arguments for an active southern distributary (the Dunavăţ, derived from the Sf. Gheorghe branch) that formed successive open-coast lobes between 2.6 and 1.3 ka. Additionally, we discuss the effects of modern anthropogenically-driven fluvial sediment reduction on the morphology and morphodynamics of the active lobes of the Danube.

"We use chronostratigraphic data from 194 organic-rich peat and lagoon points to quantitatively reevaluate the drivers of Nile Delta surface dynamics during the Holocene. Reconstructed subsidence rates range from 0.03 to 4.5 mm/yr, and are highest in the Manzala, Burullus, Idku, and Maryut lagoons, areas that correspond to deep late Pleistocene topography infilled with compressible Holocene strata; 88% of the subsidence values are <2 mm/
yr.
We suggest that during the Holocene two significant but previously underestimated contributors to changes in Nile Delta mass balance have been sediment compaction and orbitally forced changes in sediment supply. Between 8000 and 4000 calibrated (cal) 14C yr B.P., spatially averaged sedimentation rates were greater than subsidence, meaning that delta aggradation was the dominant geomorphological process at the regional scale. Since ca. 4000 cal yr B.P., a sharp climate-driven fall in Nile sediment supply, coupled with the human-induced drainage of deltaic wetlands, has rendered the depocenter more sensitive to degradation by sea-level rise and extreme flood events."

Understanding the current and future climate and environmental system requires a deep insight into the development of the global climate during the Quaternary, and the Last Glacial Cycle (LGC) in particular. High frequency climatic and environmental changes are recorded by proxy-data of sediments accumulated on the continental shelves and shallow basins of marginal seas. The sedimentary records do not only reflect changes of the environment on the global, but also on the regional and sub-regional scale. The basins receiving the load of sediments discharged by river mouth systems or coastal erosion display the history of impacts of natural and anthropogenic forcing on the environment of sediment transport from the origin to the final destination. Sedimentological source-to-sink studies allow mass balancing and detailed paleoenvironmental and paleoclimatic synopsis of local to regional development of geosystems in transitional continent – ocean position.
A Polish-Chinese research team is investigating the relation between the Hainan Island as the source and a deltaic systems SW offshore in the Beibu Gulf, South China Sea (SCS), between Marine Isotopic Stages (MIS) 4 and 1, in a source-to-sink study. Key results of the research project “Evolution of the Hainan Delta (SCS’s NW shelf) as a response to changes in paleoenvironment since Late Pleistocene – ERES” will be presented at this International Conference to be held at the University of Szczecin.
The conference is not limited to the goals of the ERES project. It is anticipated to discuss source-to-sink studies for Quaternary marginal seas in general, so that also scientists from the Baltic Sea and other comparable areas shall feel addressed to join the conference in order to discuss methodological questions of coastal research, as well as general topics of the interference of natural and natural driving forces of the global change. Related research topics are not rooted just in the academic ivory tower, but directly related to socio-economic approaches and management tasks. For this reason, not only geoscientists are invited to join the conference but also coastal engineers, socio-economists and representatives of environmental protection and planning agencies.

Although the shifting of deltaic river branches (avulsion) is a natural process that has become increasingly influenced by humans, the impact of early human activities as a driver of avulsion success has remained poorly explored. This study demonstrates how two important avulsions in the downstream part of the Rhine-Meuse delta, The Netherlands, were stimulated by human activities in the first millennium CE, before historic embankment constrained the river courses. Peatland reclamation induced land subsidence in the lower delta. This effect, together with a human-induced increase in suspended fluvial sediments and tidal backwater effects, allowed for a gradual ingression of tidal creek channels and progradation of fluvial crevasse channels into human-occupied and drained peatlands, where they eventually connected. We reconstructed the initial situation and identified the feedback loops among overbank sedimentation, tidal incursion, and land drainage subsidence that led to avulsion success. The processes and feedbacks resulting from human activities are generic and hence relevant to many other deltas today where human-induced subsidence results in tidal ingression, potentially connecting to rivers and causing unexpected avulsions.

Changes in sea level are of wide interest because they shape the sedimentary geologic record, modulate flood-related hazards, and reflect Earth’s climate. One driver of sea-level change is the erosion and deposition of sediment, which induces changes in sea level by perturbing Earth’s crust, gravity field, and rotation axis. Here we use a gravitationally self-consistent global model to explore how sediment erosion and deposition affected sea level during the most recent glacial–interglacial cycle in the northeastern Arabian Sea and the Indus River basin, where fluvial sediment fluxes are among the highest on Earth. We drive the model with a widely used reconstruction of ice mass variations over the last glacial cycle and a sediment loading history that we constructed from published erosion and deposition rate measurements. Our modeling suggests that sediment fluxes from the Indus River are large enough to produce meter- scale changes in sea level near the Indus delta in as little as a few thousand years. These sea-level perturbations are largest closest to the center of the Indus delta, and they grow larger over time as sediment deposition increases. This implies that the elevation of sea-level markers near the Indus delta will be significantly altered by sediment transfer over millennial timescales, and that such deformation should be accounted for in studies that use paleo-sea-level markers to infer past ice sheet volume or explore local processes such as sediment compaction. Our analysis highlights the role that massive fluvial sediment fluxes play in driving sea-level changes over >1000-yr timescales from the Indus River, and, by implication, from other rivers with large sediment fluxes.

Clinoforms are ubiquitous deltaic, shallow-marine and continental-margin depositional morphologies, occurring over a range of spatial scales (1-10 4 m in height). Up to four types of progressively larger-scale clinoforms may prograde synchronously along shoreline-to-abyssal plain transects, albeit at very different rates. Paired subaerial and subaqueous delta clinoforms (or 'delta-scale compound clinoforms'), in particular, constitute a hitherto overlooked depositional model for ancient shallow-marine sandbodies. The topset-to-foreset rollovers of subaqueous deltas are developed at up to 60 m water depths, such that ancient delta-scale clinoforms should not be assumed to record the position of ancient shorelines, even if they are sandstone-rich. This study analyses a large dataset of modern and ancient delta-scale, shelf-prism-and continental-margin-scale clinoforms, in order to characterise diagnostic features of different clinoform systems, and particularly of deltascale subaqueous clinoforms. Such diagnostic criteria allow different clinoform types and their dominant grain-size characteristics to be interpreted in seismic reflection and/or sedimentological data, and prove that all clinoforms are subject to similar physical laws. The examined dataset demonstrates that progressively larger scale clinoforms are deposited in increasingly deeper waters, over progressively larger time spans. Consequently, depositional flux, sedimentation and progradation rates of continental-margin clinoforms are up to 4-6 orders of magnitude lower than those of deltas. For all clinoform types, due to strong statistical correlations between these parameters, it is now possible to calculate clinoform paleobathymetries once clinoform heights, age spans or progradation rates have been constrained. Muddy and sandy delta-scale subaqueous clinoforms show many different features, but all share four characteristics.

During the mid-Holocene, the first large-scale civilizations emerged in lower alluvial systems after a marked decrease in sea-level rise at 7–6 kyr. We show that as the landscapes of deltas and lower alluvial plains adjusted to this decrease in the rate of relative sea-level rise, the abundance and location of resources available for human exploitation changed as did the network of waterways. This dynamic environmental evolution contributed to archaeological changes in the three fluvio-deltaic settings considered herein: Egypt, Mesopotamia, and the Huang He in China. Specifically, an increase in the scale and intensity of agricultural practice, and the focussing of power toward a single city can be interpreted as responses to these environmental changes. Other archaeological observations, and the cultural trajectories leading to the formation of the Primary States also need to be considered in light of these evolving landscapes.

Clinoforms are ubiquitous deltaic, shallow-marine and continental-margin depositional morphologies, occurring over a range of spatial scales (1-10 4 m in height). Up to four types of progressively larger-scale clinoforms may prograde synchronously along shoreline-to-abyssal plain transects, albeit at very different rates. Paired subaerial and subaqueous delta clinoforms (or 'delta-scale compound clinoforms'), in particular, constitute a hitherto overlooked depositional model for ancient shallow-marine sandbodies. The topset-to-foreset rollovers of subaqueous deltas are developed at up to 60 m water depths, such that ancient delta-scale clinoforms should not be assumed to record the position of ancient shorelines, even if they are sandstone-rich. This study analyses a large dataset of modern and ancient delta-scale, shelf-prism-and continental-margin-scale clinoforms, in order to characterise diagnostic features of different clinoform systems, and particularly of deltascale subaqueous clinoforms. Such diagnostic criteria allow different clinoform types and their dominant grain-size characteristics to be interpreted in seismic reflection and/or sedimentological data, and prove that all clinoforms are subject to similar physical laws. The examined dataset demonstrates that progressively larger scale clinoforms are deposited in increasingly deeper waters, over progressively larger time spans. Consequently, depositional flux, sedimentation and progradation rates of continental-margin clinoforms are up to 4-6 orders of magnitude lower than those of deltas. For all clinoform types, due to strong statistical correlations between these parameters, it is now possible to calculate clinoform paleobathymetries once clinoform heights, age spans or progradation rates have been constrained. Muddy and sandy delta-scale subaqueous clinoforms show many different features, but all share four characteristics.

We investigated the Holocene evolution of the Godavari delta along the east coast of India, by analyses of land- forms and 11 borehole cores collected from the delta plain during 2010–2013 with 113 14C dates. The Godavari delta covering an area of 5820 km2 is one of the world's largest wave-dominated deltas fringed by a ~ 30 km wide beach-ridge plain. Our analysis of sediment facies and their ages indicated that the Holocene marine sequence thickens seaward from ~10 m to more than 50 m and that the local relative sea level rapidly rose from 43.5 m to 7.5 m below the present sea level during 10.9–8.0 cal ky BP followed by a slow rise up to its current level around 5 cal ky BP. Spatio-temporal variations in sediment accumulation rates and palaeo-shorelines for the last 6 ky revealed successive changes of the main depocentre (delta lobe). We recognised six stages of delta evo- lution with distinct cyclic shifts of delta lobes controlled by avulsions. A linear beach ridge located 12–14 km in- land from the present shoreline, which separates the first three lobes from the last three, represents the effect of coastal erosion of past cuspate delta lobes, as does the current linear shoreline of the central part of the delta. Our study documents continuous net progradation during the Holocene on millennial to centennial time scales. How- ever, a considerable decrease of sediment discharge due to dam construction and water diversion since the 1970s has exacerbated coastal erosion, resulting in shrinking of the Godavari delta plain and tipping it into a persistent destruction phase.
© 2015 Elsevier B.V. All rights reserved.

The progradation of the Medjerda delta has been the subject of many studies since the 19th century. The scale and the rapidity of this phenomenon interested researchers in various fields early on, such as geomorphology, geology, palaeogeography, history, archaeology, or geoarchaeology. Indeed, the delta prograded by around 10 km over 3 millennia. At the time of its foundation supposedly at the end of the 12th century BC, the Phoenician city of Utica was located on a promontory bathed by the sea, but the sediments carried by the Medjerda progressively sealed the bay, leaving the tip of the Utica promontory now 10 km inland. This area is therefore an exception to the general pattern along the Tunisian coast, since as over the same period everywhere else there is a regression of the coastline, owing to a sea level rise of several decimeters. Based on multi-proxy analyses of two coring transects, this paper aims to reconstruct the palaeoenvironments and the palaeogeography of the Medjerda delta's progradation since the mid-Holocene, some aspects of which are described in ancient sources. The results highlight in particular an episode of high-intensity flooding around the 4th century AD, which is consistent with episodes of high floods and an increase in sedimentation rates recorded in the watershed at the end of the Roman period. The gradual abandonment of the city of Utica can certainly be related to the activity of the Medjerda River, but our results show that it is because of an increase of fluvial sediment contribution in connection with an erosive crisis in the headwaters, and not because of the change of course of the river, which had occurred long before.

The present study deals with the reconstruction of the ancient courses of the Tigris and the Euphrates in the Mesopotamian floodplain, which covers most of the central and southern parts of Iraq. The focus is on tracing palaeochannel courses, determining when these palaeochannels were active, and understanding the patterns of avulsion and its impact on human settlements of ancient civilisations.
The research was carried out using a combination of geological, geomorphological, remote sensing, historical and archaeological approaches. Fieldwork included “groundtruthing” of the remote sensing work. A total of thirty seven boreholes were dug, sedimentary and geomorphologic documentation has been carried out, and twenty five shell samples were collected, and analysed by radiocarbon dating.
This study has reconstructed palaeochannels and archaeological sites within the area of southern Mesopotamia; intensive networks of palaeochannels and archaeological sites within the study area have been identified. More than eight thousand archaeological sites have been plotted during this study, and most of them show a location and alignment consistent with an identified palaeochannel.
Eleven major river avulsions and their nodes have been identified, five for the Euphrates and six for the Tigris. It has been found that these avulsions contributed to the shaping, formation and aggradation of both the ancient and present–day landscapes of the floodplain. Two kinds of avulsion have taken place in the floodplain, re-occupational and progradational. In the first of these types of avulsion, the major flow diverted into a previously existing channel. In contrast, the progradational avulsion began by inundating a large section of the floodplain between elevated ridges, producing prograding deposits that filled topographic lows of the floodplain.
These avulsions have affected the distribution, flourishing and degradation of human settlements of the southern Mesopotamian civilisations. The present study has demonstrated how human impact played a leading role in distribution of sediments across the floodplain and shaping both the Holocene and the recent landscapes of the Mesopotamian floodplain. By using periods of human occupation of archaeological sites to date associated palaeochannels, we can get acceptable accuracy on their timing and duration, and can give clear indications about the activity of a given channel.

En este trabajo se realiza un análisis preliminar del registro arqueológico recuperado en el
sitio Médanos de Escobar. Se trata de un depósito situado en los Bajíos Ribereños meridionales
(humedal del río Paraná inferior). Se presenta la estratigrafía y la cronología del sitio, algunos
aspectos geomorfológicos del área y las principales características del registro arqueológico
recuperado. Finalmente se discute y compara la información generada con la obtenida en otros
sitios con el fin de establecer similitudes y diferencias que nos permitan avanzar en el conocimiento
de la variabilidad arqueológica generada por las poblaciones cazadoras-recolectoras
que habitaron el área de estudio en los últimos 2500 años 14C AP (Holoceno tardío).

Koster, K., Stafleu, J. & Stouthamer, E., 2018. Differential subsidence in the urbanized coastal-deltaic plain of the Netherlands. Netherlands Journal of Geosciences, doi: 10.1017/njg.2018.11

The urbanised peat-rich coastal-deltaic plain of the Netherlands is severely subsiding due to human-induced phreatic groundwater level lowering, as this causes peat layers to compress and oxidise. To determine the potential susceptibility of this area to future subsidence by peat compression and oxidation, the effects of lowering present-day phreatic groundwater levels were quantitatively evaluated using a subsidence model. Input were a 3D geological subsurface voxel-model, modelled phreatic groundwater levels, and functions for peat compression and oxidation. Phreatic groundwater levels were lowered by 0.25 and 0.5 m, and the resulting peat compression and oxidation over periods of 15 and 30 years were determined. The model area comprised the major cities Amsterdam and Rotterdam, and their surrounding agricultural lands. The results revealed that for these scenarios agricultural areas may subside between 0.3 and 0.8 m; potential subsidence in Amsterdam and Rotterdam is considerably lower, less than 0.4 m. This is due to the presence of several metres thick anthropogenic brought-up soils overlying the peat below the urban areas, which has already compressed the peat to a depth below groundwater level, and thus minimises further compression and oxidation. In agricultural areas peat is often situated near the surface, and is therefore highly compressible and prone to oxidation. The averaged subsidence rates for the scenarios range between 7 and 13 mm a −1 , which is corresponds to present-day rates of subsidence in the peat areas of the Netherlands. These results contrast with the trend of coastal-deltaic subsidence in other deltas, with cities subsiding faster than agricultural areas. This difference is explained by the driver of subsidence: in other deltas, subsidence of urban areas is mainly due to deep aquifer extraction, whereas in the Netherlands subsidence is due to phreatic groundwater level lowering.

This paper describes the sedimentary architecture, chronostratigraphy and palaeogeography of the late Middle and Late Pleistocene (Marine Isotope Stage / MIS 6-2) incised Rhine-valley fill in the central Netherlands based on six geological transects, luminescence dating, biostratigraphical data and a 3D geological model. The incised-valley fill consists of a ca. 50 m thick and 10-20 km wide sand-dominated succession and includes a well-developed sequence dating from the Eemian interglacial (Last Interglacial).
The lower part of the valley fill contains coarse-grained fluvio-glacial and fluvial Rhine sediments that were deposited under Late Saalian (MIS 6) cold-climatic periglacial conditions and during the transition into the warm Eemian interglacial (MIS 5e-d). This unit is overlain by fine-grained fresh-water flood-basin deposits, which are transgressed by a fine-grained estuarine unit that formed during marine high-stand. This ca. 10 m thick sequence reflects gradual drowning of the Eemian interglacial fluvial Rhine system and transformation into an estuary due to relative sea-level rise. The chronological data suggests a delay in timing of regional Eemian interglacial transgression and sea-level high-stand of several thousand years, when compared to eustatic sea-level. As a result of this glacio-isostatic controlled delay, formation of the interglacial lower delta took only place for a relative short  period of time and delta progradation was limited. During the cooler Weichselian Early Glacial period (MIS 5d-a) deposition of deltaic sediments continued and extensive westward progradation of the Rhine delta occurred.
Major parts of the Eemian and Weichselian Early Glacial deposits were eroded and buried as a result of sea-level lowering and climate cooling during the early Middle Weichselian (MIS 4-3). Near complete sedimentary preservation occurred along the margins of the incised valley  allowing the detailed reconstruction presented here.

La Berre est un fleuve côtier encadré par la chaîne
des Corbières à l’ouest et la lagune de Bages-Sigean
à l’est. Son delta s’étend du site de Pech
Maho à son actuelle embouchure, en passant par une
ancienne dépression aujourd’hui comblée, connue sous
le toponyme “Plaine du Lac”, objet de cette étude.
Cette unité géomorphologique constitue un
terrain de recherche particulièrement intéressant par la
complexité de ses paysages fluvio-lagunaires et par la forte
mobilité des milieux. Cette mobilité est à la fois induite
par la variation des apports sédimentaires mais aussi par
de nombreux phénomènes de défluviation de la Berre. Ce
fleuve est à l’origine du comblement de la Plaine du Lac.
L’évolution de son delta est un élément important pour la
compréhension d’un environnement qui a été densément
occupé, notamment durant la Protohistoire. L’habitat
protohistorique de Pech Maho (Sigean, Aude) est occupé
du vie au iiie s. a.C. Site côtier faisant manifestement office
de débarcadère, il bénéficie d’une situation géographique
avantageuse entre Roussillon et bas Languedoc occidental,
ce qui lui confère une fonction de relais entre le monde
indigène et la sphère méditerranéenne 1.
L’intérêt de cette recherche repose sur l’étude
des dynamiques sédimentaires liées à la Berre et de leur
évolution, ainsi qu’à l’identification et la caractérisation des
différents milieux qui se sont succédé durant l’Holocène,
en lien avec le site de Pech Maho.
Le présent travail propose une reconstitution de l’évolution paléogéographique du delta de la Berre à partir de l’étude
du carottage SC03, de 22 m de profondeur. Réalisé durant l’été 2010, le carottage et les analyses paléoenvironnementales
font partie du projet PEPS-CNRS “Autour de Pech Maho (Aude) : mobilité d’un territoire face à l’interface des milieux
marin et terrestre, de l’âge du Bronze au Moyen Âge” 2. Outre la description lithostratigraphique, différentes analyses ont
été réalisées : l’évolution des milieux a été déterminée grâce à une étude malacologique, les marqueurs sédimentologique
(texture et granulométrie des sables), géophysique (susceptibilité magnétique) et géochimique (teneur en carbone organique
et inorganique) renseignent sur les conditions de dépôts dans les différents milieux sédimentaires et sur les évolutions
naturelles ou d’origine anthropique des processus morphosédimentaires.

A $40 m sediment core (FZ4) was collected from the Fuzhou Basin, near the lower reaches of the Min River, in Fujian Province on the southeast coast of China. The sediment and pollen record contributes to our understanding of Holocene paleogeography, including local changes in vegetation and climate in the context of Neolithic cultural developments. The sediment record reveals a fluvial environment in the Fuzhou Basin during the late Pleistocene, and it demonstrates that a change from fluvial to estu-arine conditions at $9000 cal yr BP resulted from postglacial sea level rise. Evidence of abundant marine diatoms and tidal flat laminations observed in the FZ4 sediments, implies that the Fuzhou Basin was under marine influence between $9000 and $2000 cal yr BP. After 2000 cal yr BP, a rapid retreat in coastline associated with fluvial aggradation and coastal progradation produced more shallow water for wetlands and initiated formation of the floodplain landscape. The pollen record reveals the presence of a dense subtropical forest between ca. 9000 and 7000 cal yr BP, representing the Holocene thermal maximum , which is linked with rising sea level and marine transgression in the Fuzhou Basin. Between ca. 5500 and 2000 cal yr BP, the thermophilous forest dominated by Castanopsis retreated and coniferous forest expanded, reflecting moderate climatic cooling during this period. Timing of the high frequencies for Pinus and ferns correspond with the mid-late Holocene cooling trend recorded in local mountain peatland and coastal regions of the lower Yangtze and Hanjiang deltas. Anthropogenically induced land cover change was negligible prior to the Tanshishan cultural period, which marks the beginning of Neolithic era sedentary village life on the Fujian coast around 5500 BP. The pollen transition at ca. 3000–1500 cal yr BP, distinguished by rising frequencies of Poaceae and taxa (including Cyperaceae and Artemisia) closely associated with agricultural land cover, indicates exploitation of newly formed lowlands in the emerging Min River floodplain. The historic era intensification of rice agriculture is reflected in this trend of rising frequencies of Poaceae. After ca. 2000 cal yr BP, we observe the onset of a marine regression followed by evidence for an intensely human-impacted environment characterized by sharp rises in pioneer plants such as Poaceae and Dicranopteris. This transition coincides with a rapid retreat of coastline and emergence of the Fuzhou Basin floodplain.

Wide estuaries are natural magnets for urban development. Several of the World’s major cities developed around estuaries, but at the same time encroached upon some of the most complex and vital ecosystems. Sea-level rise threatens to submerge both rare wetland habitat and essential urban areas and infrastructure. This prospect discloses the urgency of balancing urban development and environmental protection in Metropolitan Estuaries. The hard task of dealing with this threat may provide the opportunity to promote an integrated approach to regional planning, where the necessary adaptation of cities to sea-level rise could equally promote the preservation, or even the enhancement, of wetland habitat. The two case study metropolitan estuaries, San Francisco Bay (California, USA) and the Tagus Estuary (Lisbon, Portugal), share striking similarities in terms of morphology. They both host large metropolitan areas and important wetland ecosystems. Nevertheless, a finer analysis of development patterns reveals crucial differences in the extent of shoreline alteration and types of land use that now encroach upon natural estuarine habitat. The comparative study of both estuaries provides mutually beneficial insights on the shortcomings of each system, and helps identify opportunities to enhance coastal zone management, adaptive governance and environmental planning efforts. The evolution of both estuaries throughout the Holocene is reconstructed, with special emphasis on the process of anthropogenic alteration. While this impact has been significant and continuous in the Tagus Estuary for over two millennia, large scale disturbance of the San Francisco Bay was concentrated in the last two centuries. The legal frameworks that have guided, with varying degrees of effectiveness, the process of wetland reclamation and landfilling share a common ancestry in the Roman Law. These have evolved continuously in Lisbon and the State has upheld with relative success the provision to keep estuarine lowlands in public control, even as they were steadily transformed to farmland. In San Francisco, a period of deep disturbances over the Sacramento River’s hydrology was coupled with extremely fast and under regulated development of lowlands. During a short period, the property of these lands, which would theoretically fall within the Public Trust, was transferred to local governments and private landowners, which led to their steady transformation onto salt ponds, industrial zones and even residential neighborhoods. As a consequence, the Bay Area now has extensive developed areas at very low elevations, vulnerable to low levels of sea-level rise, and remaining wetlands are now heavily encroached upon by urban development. Around the Tagus Estuary, while most original wetlands have long been drained for farmland, the remaining patches are adjacent to non-urban land uses, which could facilitate future efforts of restoration or allow wetland migration with rising seas. A comparative modelling of sea-level rise flooding over existing land uses reveals that, while around the Tagus Estuary most reclaimed lowlands are reserved for farmland and urban development over landfill is limited, the extent of developed urban areas at very low elevations is much greater around the SF Bay, which renders the region more vulnerable to early stages of SLR. Nonetheless, both cities have begun to incorporate climate adaptation onto their main environmental planning blueprints, for which they can be seen as early adopters of local sea-level rise adaptation strategies. Through interviews with stakeholders and document analysis, the planning and decision-making exercises that led to the recent elaboration of the first Tagus Estuary Management Plan, and the Bay Plan Climate Change Amendment, are analyzed and discussed. Lisbon benefits from a very simple, top-down, planning structure, with a handful of public entities directly communicating and articulating stakes and approaches along the planning process. A lack of transparency as to some specific interventions and a still somewhat incipient tradition of public participation have contributed to protract the Plan’s final approval. The Bay Area institutional framework is well-used to collaborative planning efforts, which are usually successful in articulating conflicting interests, but are prone to limitations derived from narrow, and often difficult to expand, mandates for environmental planning agencies, within an extremely complex, multi-level, governance structure involving three levels of government and very active interest groups. While broad mitigation/adaptation strategies are decided at the National or State levels, the actual implementation of SLR adaptation measures often require a great deal of involvement of local actors. Given that it is at this juncture that adaptation takes a concrete spatial expression, this is also the moment when land-use conflicts arise. Local governments are left with much of the burden of mediating competing interests, between urban development, environmental protection, and other social demands. In some instances, the prospect of shoreline development may be very attractive for both property owners/developers and local governments, given the potential land value and economic benefits, but these have to be weighed against the medium-/long-term costs of defending these assets from rising sea-levels. In San Francisco Bay, there is an increasing awareness of the challenges posed by SLR, but the institutional arrangements are complex, and communication between the different public agencies/departments is not always as streamlined as it could be. Some agencies and departments need to adapt their procedures in order to remove institutional barriers to adaptation, but path dependence is an obstacle. The several projects where different federal and state agencies are partnered with local governments highlight the benefits of a more frank and regular communication between public actors. It also emphasizes the benefits of a coordination of efforts and strategies, something that was eroded in the transition from government-led policies to a new paradigm of local-based adaptive governance. Whereas the articulation of public actors is often easy to address by increasing communication and coordination, conflicts involving private landowners and developers may be much complicated by the threat of litigation. The lack of a strong legal backing to public environmental protection mandates is a major obstacle to shoreline planning around the Bay and elsewhere, and this is highlighted by the extreme caution of some public agencies in upholding their jurisdictions over private property. Environmental NGOs have, in the case of California, a big role to play, as they are able to resort to the same legal and lobbying instruments as the developers, and may help even-out the field between public stakeholders with limited legal and economic resources, and powerful private developers with nothing to lose. There is seemingly a sense of urgency in pushing for the development of shoreline properties, as public opposition to development on locations exposed to SLR is most likely to increase in the coming decades. At the same time, NGOs and public agencies are aware of the stress wetlands will be under as the rates of SLR increase towards the end of the century. “Green”, or ecosystem-based, adaptation is already on the way around the Bay. Large scale wetland restoration projects have already been concluded, and further action now often requires articulation with the reinforcement of flood defense structures, given the level of urban encroachment. While levee setback, or removal, would provide greater environmental benefit, the need to protect urban areas and infrastructure has led to the trial of ingenious solutions for promoting wetland resilience while upgrading the level of protection granted by levees.

According to ancient literary tradition, Utica is considered to be one of the first three Phoenician foundations in the Western Mediterranean, supposedly founded in 1101 BC by Levantines from Tyre. In the Phoenician and Roman periods it was an important merchant coastal town, on a promontory facing the sea. Over the centuries Utica lost its access to the sea, and its ports silted up as a consequence of the activity of the wadi Medjerda, which flowed to the south of the city. Despite over a century of investigation by archaeologists and associated researchers, the location of the city’s harbour structures from the Phoenician and Roman periods remains unknown, buried under sediments resulting from the progradation of the Medjerda. Based on the study of sedimentary cores, the research presented here highlights the existence of a long maritime façade to the north of the Utica promontory in Phoenician and Roman times. A deep-water marine environment is attested in the former bay from the 6th mill. BC and the depth of the water column along the northern façade was still 2 m around the 4th – 3rd c. BC. Another core to the east of the Kalaat El Andalous promontory showed the possibility that this sector was a sheltered harbour during the Phoenician and Roman periods. This paper illustrates the contribution of geoarchaeology to address this archaeological problem and to understand the relations of this important port city with the sea.

The Holocene evolution of the Ombrone River delta has been investigated using morphological and sedimentological evidence. The delta had a lagoon-like prehistoric evolution, while seawards the growth occurred mainly in historical times. The data obtained, together with the available historical and archeological documentation, enable a quantitative evaluation of the volume of the emerged part of the delta to be made. Moreover, for the apical area, it has been possible to calculate the annual average increase in the volume of deposition during Etruscan and Roman times, as well as during the Middle Ages and since the Renaissance up to now. It has been possible to estimate the periods during which wind exerted a more important role in shaping the delta morphology. The volume of sediments deposited during the last 6000 years has been estimated at 1766-106 m3. A combination of climatic conditions, littoral dynamics and human action appears to have driven the dynamics of the delta growth, which, however, was not continuous, but active especially during the last 3000 years. During this period, about the 80% of the whole delta volume seems to have deposited. High rates of sedimentation occurred between the 16th and the 19th centuries (a cold and moist period coinciding with the Little Ice Age), when the delta took the typical shape of microtidal wave-dominated deltas.

This article presents a new proposal for the geomorphological evolution of the Barcelona seafront, between Mount Tàber and Ciutadella Park, based on the integration of new  sedimentological information, radiocarbon datings and
archaeological data. This data reveals the existence of a
pre-Roman cove at the foot of Mount Tàber which would be straightened with the sedimentary deposits of the river Besòs from the Roman period, when the offshore bar of Santa Maria
del Mar–El Born market was formed. During the medieval period, the formation of offshore bars shaped protected areas that would be used as port zones. The gradual effect of the
deltaic progradation of the river Besòs marks the coastal dynamic of this area with the arrival of a river channel in the
16th century. The construction of successive wharf sections throughout the 17th century accelerated the coastal progradation and gave way to La Barceloneta plain.

Major deltas and their adjacent coastal plains are commonly linked by means of coast-parallel fluxes of water, sediment, and nutrients. Observations of the evolution of these interlinked systems over centennial to millennial timescales are essential to understand the interaction between point sources of sediment discharge (i.e. deltaic distributaries) and adjacent coastal plains across large spatial (i.e. hundreds of kilometres) scales. This information is needed to constrain future generations of numerical models to predict coastal evolution in relation to climate change and other human activities. Here we examine the coastal plain (Chenier Plain, CP) adjacent to the Mississippi River delta, one of the world's largest deltas. We use a refined chronology based on 22 new optically stimulated luminescence and 22 new radiocarbon ages to test the hypothesis that cyclic Mississippi subdelta shifting has influenced the evolution of the adjacent CP. We show that over the past 3 kyr, accumulation rates in the CP were generally 0–1 Mt yr −1. However, between 1.2 and 0.5 ka, when the Mississippi River shifted to a position more proximal to the CP, these rates increased to 2.9 ±1.1 Mt yr −1 or 0.5–1.5 % of the total sediment load of the Mississippi River. We conclude that CP evolution during the past 3 kyr was partly a direct consequence of shifting subdeltas, in addition to changing regional sediment sources and modest rates of relative sea-level (RSL) rise. The RSL history of the CP during this time period was constrained by new limiting data points from the base of overwash deposits associated with the cheniers. These findings have implications for Mississippi River sediment diversions that are currently being planned to restore portions of this vulnerable coast. Only if such diversions are located in the western portion of the Mississippi Delta plain could they potentially contribute to sustaining the CP shoreline. Our findings highlight the importance of a better understanding of mud-dominated shorelines that are often associated with major deltas, in light of the enormous investments in coastal management and restoration that will likely be made around the globe, now and especially later during this century.

River deltas began forming around 7000 years BP because of the stabilization of mean sea level and high sedimentary inputs at base-level. The natural variety of wetland environments on clastic coasts, in particular deltas, explains in major part the important disparities in harbour contexts. These different geomorphological contexts led to specific pressures and potentialities for maritime activities. In this presentation, I will describe an investigation of four different sites using a combination of earth science and archaeological tools.
At the deltaic scale, we investigate 7000 years of environmental changes on the Kuban delta (Taman Peninsula, Russia). We show that the local inhabitants faced significant natural constraints that have undoubtedly dictated the development and decline of some cities, in particular during archaic a nd classical periods.
At the local scale (ancient settlements), we show that the natural environment, such as lagoons or estuaries were particularly attractive for ancient population looking for good mooring areas. We focus on the potentialities and constraints of such environments for the development of harbours in three different sites: Akko (Haifa Bay, Israel), Pollentia (Mallorca, Balearic archipelago) and Halmyris (Danube delta, Romania).

Les Étangs de Villepey correspondent à une lagune occupant la partie méridionale de la basse vallée de l'Argens. Afin de préciser la dynamique hydro-sédimentaire et l'évolution de ce milieu sur le temps long, un carottage de 8,75 m de profondeur a été réalisé en bordure de la lagune en 2004. Les découvertes anciennes de vestiges d'épave(s) antique(s) dans les étangs posaient la question de l'évolution du littoral dans ce secteur depuis l'Antiquité. L'analyse, stratigraphique appuyée par l'étude des lithofaciès, (faciès sédimentaire, granulométrie des sables) et des biofaciès (ostracofaune et malacofaune benthique), a permis d'identifier précisément les paléo-biotopes et les différentes dynamiques sédimentaires, dont le calage chronologique est assuré par 4 dates radiocarbone. Les paléoenvironnements révélés par la carotte Vil2 mettent en évidence la présence d'un milieu marin vers 3 900 av. J.-C. au moins, qui évolue en lagune à partir de l'Âge du Fer. À l'époque romaine, la lagune est protégée et communique avec la mer ; le tirant d'eau que l'on peut y restituer n'exclue pas qu'elle ait pu faire l'objet d'un aménagement portuaire. La persistance de milieux lagunaires à Villepey depuis environ 2 400 ans met également en évidence une progradation dissymétrique de la ria de l'Argens, plus rapide sur le flanc nord (secteur de Fréjus) que sur le flanc sud de la vallée, dans le secteur de Villepey.

The rapid increment of low and middle-income consumers is exerting pressure on the food supply in urban areas. The objective of the study was to identify the present status of rooftop gardening. The study was conducted in the 4 selected residential areas of Dhaka city through plot to plot interview by using questionnaire. Land use nature is divided into four categories like residential, commercial, educational and mixed. Field survey was conducted on 1376 buildings in Dhanmondi, 391 buildings in Lalmatia, 272 buildings in Mohakhali Defense Officers Housing Society (DOHS) and 697 buildings in Uttara 13 no. Sector. Study found that, 39.1%, 59.2%, 36.6 % and 22.2% buildings have rooftop gardening in those selected locations respectively. The study reveals that, nearly one-third of the buildings (36.4%) contain rooftop gardening which basically depends on the aesthetic sense and moral values of individuals. Government should appreciate initiatives and consider proper planning policy to motivate citizen of the urban areas for planting fruit plants and vegetable in their roof. RTG system may also contribute to achieving the Sustainable Development Goals (SDGs). The proposed study identifies the need for long-term policy measures for rooftop gardening that can become the basis for a sustainable approach for urban agriculture.

Flaux, C., Giaime, M., Pichot, V., Marriner, N., el-Assal, M., Guihou, A., Deschamps, P., Claude, C., and Morhange, C.: The late Holocene record of Lake Mareotis, Nile Delta, Egypt, E&G Quaternary Sci. J., 70, pp. 93-104.

https://doi.org/10.5194/egqsj-70-93-2021, 2021.

Abstract: Lake Maryut (northwestern Nile Delta, Egypt) was a key feature of Alexandria's hinterland and economy during Greco-Roman times. Its shores accommodated major economic centers, and the lake acted as a gateway between the Nile valley and the Mediterranean. It is suggested that lake-level changes, connections with the Nile and the sea, and possible high-energy events considerably shaped the human occupation history of the Maryut. To reconstruct Lake Maryut hydrology in historical times, we used faunal remains, geochemistry (Sr isotopic signature of ostracods) and geoarcheological indicators of relative lake-level changes. The data show both a rise in Nile inputs to the basin during the first millennia BCE and CE and a lake-level rise of ca. 1.5 m during the Roman period. A high-energy deposit, inferred from reworked radiocarbon dates, may explain an enigmatic sedimentary hiatus previously attested to in Maryut's chronostratigraphy.

Seabed survey was undertaken in territorial waters off Rushikulya River, Bay of Bengal by Geological Survey of India (GSI) during ST-223 cruise of R.V. Samudra Kaustubh. The work was aimed at determining the sediment distribution pattern and coastal changes associated with sea level rise. The sediment of the inner to middle shelf region of the central part of east coast near the spit of the Rushikulya River mouth is characterized by very hard, compact dark grey clayey silt and clay with medium to coarse sand and layers of wood pieces at different levels formed in the point bar of meandering Rushikulya River channel in a tidal flat environment. Poor sorting of sediments is due to distributed system and channelized systems. These alternating layers of sand and mud are a distinctive feature of tidally influenced meandering channels. All these features coupled with ardent smell of sulphur and carbonaceous material-rich sedimentation indicate a tidal mud flat environment with tide channels and tidal sand bars in front of the Rushikulya River. The submerged paleo-spit of the Rushikulya River marks the limit of the paleogegraphy associated with Rushikulya River.

The growth of Chilia deltaic lobes reflects a drastic reorganization of the Danube delta that accompanied
its rapid expansion in the late Holocene. Using new cores collected at the apices of the two older Chilia
lobes, together with historical maps and satellite photos, we find that a partial avulsion since 1500
years BP led to a gradual rejuvenation of the Chilia distributary. This process led to the successive infilling
of a lake and a lagoon and subsequently to the construction of an open coast lobe at the Black Sea coast.
The Chilia branch became the largest Danube distributary, reaching its maximum sediment load in the
last 300 years as the southernmost St. George branch lost its previous dominance. Here, we propose that
the intensive deforestation of Danube’s lower watershed leading to this delta reorganization has
historical cultural causes: an increase in sheep and timber demand associated to the Ottoman Empire
expansion in Eastern Europe followed by the adoption of maize agriculture as a result of the Columbian
Exchange. Rapid industrialization-driven damming during the Communist Era led to the current
generalized sediment deficit for the Danube. Under these conditions, the modern Chilia lobe is rapidly
remodeled by waves and may join the Sulina coast to impede navigation on the Sulina canal.

Forty years after the publication of the book "The Romanization of the ancient Delta Padano", Ferrara 1975, the author performs a review of the new topographical and epigraphic data and related problems, especially on the Po River and the territories of the current province of Ferrara (Italy).

Nereo Alfieri, after the ancient topography of the Marche region, studied that of Spina and ‘Delta Padano’ (Ferrara). He made a remarkable contribution to the reconstruction of an ever-changing landscape, where he identified the Padus Vetus or River of Spina (Eridanus) and the sancta Maria in Pado Vetere Church, a Ravenna foundation of the 6th century AD.

The growth of Chilia deltaic lobes reflects a drastic reorganization of the Danube delta that accompanied
its rapid expansion in the late Holocene. Using new cores collected at the apices of the two older Chilia
lobes, together with historical maps and satellite photos, we find that a partial avulsion since 1500
years BP led to a gradual rejuvenation of the Chilia distributary. This process led to the successive infilling
of a lake and a lagoon and subsequently to the construction of an open coast lobe at the Black Sea coast.
The Chilia branch became the largest Danube distributary, reaching its maximum sediment load in the
last 300 years as the southernmost St. George branch lost its previous dominance. Here, we propose that
the intensive deforestation of Danube’s lower watershed leading to this delta reorganization has
historical cultural causes: an increase in sheep and timber demand associated to the Ottoman Empire
expansion in Eastern Europe followed by the adoption of maize agriculture as a result of the Columbian
Exchange. Rapid industrialization-driven damming during the Communist Era led to the current
generalized sediment deficit for the Danube. Under these conditions, the modern Chilia lobe is rapidly
remodeled by waves and may join the Sulina coast to impede navigation on the Sulina canal.

Pollution of groundwater in the Bengal Basin (Bangladesh and West Bengal, India) by arsenic (As) puts at risk the health of more than 100 million consumers. Using 1,580 borehole lithological logs and published hydrochemistry on 2,387 wells, it was predicted that low-As (<10 μg/L) groundwater exists, in palaeo-interfluvial aquifers of brown sand capped by a protective palaeosol, beneath at least 45,000 km2 of the Bengal Basin. The aquifers were predicted to be at a depth of as little as 25 m below ground level (mbgl), and typically no more than 50 mbgl. The predictions were confirmed along an east–west traverse 115 km in length (i.e. across half of Bangladesh) by drilling 28 new boreholes to 91-m depth to reveal subsurface sedimentology, and by mapping As distribution in groundwater. The aquifers identified occur at typically <40 mbgl and so are accessible with local drilling methods. A protective palaeosol that caps the palaeo-interfluvial aquifers prevents downward movement into them of As-polluted groundwater present in shallower palaeo-channel aquifers and ensures that the palaeo-interfluvial aquifers will yield low-As groundwater for the foreseeable future. Their use, in place of the shallower As-polluted palaeo-channel aquifers, would rapidly mitigate the health risks from consumption of As-polluted groundwater.

The asymmetric Sf. Gheorghe lobe is the only active lobe in the Danube delta associated with a river-mouth bar
(and related barrier islands and spits) that has continuously displayed cyclic development during the last 1500
years. During the early cycles, the Sf. Gheorghe distributary experienced a significant increase in sediment load
(by an order of magnitude) as a result of the successive avulsions occurred 1.5–1.2 ka, which redistributed
more water and sediment captured from the neighboring branches of Împuţita (southern distributary of the
Sulina arm) and Dunavăţ. Morphological and sedimentological analyses together with a newly obtained chronology
throw light on the multiple ridgeset (10) structure of Sf. Gheorghe lobe, each of them (excepting the first
one) following a common evolutionary pattern reflected by the cyclic succession of the recurring stages: i) subaqueous
mouth bar building, ii) barrier island emergence, and iii) transformation into a barrier spit with several
secondary spits. The spits become encased into the muddy deltaic plain as narrow sandy ridges building out on
the downdrift side of the lobe as a barrier-marsh plain, whereas the updrift side constantly accreted fed by
longshore currents, forming a classic beach ridge plain. The size of each ridgeset increased exponentially with
every new cycle due to the constant lengthening of the coastline as the downdrift side of the lobe advanced seaward
through a series of progressively larger similar quadrilaterals, yielding a corresponding geometric progression
of the delta front size. Even though each newly formed ridgeset (cycle) had a longer lifespan (the latest
cycles lasting 4–5 times longer than the first ones: 200–440 years versus 50–80 years), the evolutionary model
remained unchanged as long as the balance between wave- and river-borne sediments, defined by the sedimentary
index (Si), remained constantly low(Si ≤ 0.1),whereas the mean advance rates of the river mouth remained
constant at c.10 m/year. Abrupt changes occurred within the last cycle (since the beginning of the 20th century)
as a consequence of human-induced depletion of sediment supplied by the Danube flow, and is mainly expressed
by the complete cessation of the updrift coastal progradation and the prevalence of erosion in front of the river
mouth. These changes, which engendered a threefold increase of the Si (0.37 at present), are reflected by the recent
(1930s–present) river mouth dynamics, characterized by cessation of its long-term seaward expansion in
favor of downdrift migration. This is indicative of the transition of the Sf. Gheorghe mouth from an asymmetric
to a deflected wave-influenced delta morphology whose current developments mark a significant change in
the multicentennial cyclic evolutionary pattern. The asymmetric to deflected transition reflects the net increase
in the influence of wave-driven sediment circulation on river mouth morphology, corresponding to a critical Si
threshold of ca. 0.2 (≤0.2: asymmetric; >0.2: deflected).

Pre-Hispanic mounds, known as "cerritos," "cerritos de indios," or "aterros" across southeastern South America, are one of the most conspicuous and well-studied cultural manifestations in lowlands archaeology. Nevertheless, in the Upper Delta of the Paraná River, mounds are rarely studied, and even their anthropic origin is under debate. This could be related to the fact that anthropogenic mounds are located on a floodplain where other "mound-like" natural geoforms (generated by fluvial processes) are also present. In addition to this, the natural geoforms also contain evidence of Holocene human occupation (sherds, bones, charcoal, humans burials, etc.), which can lead to interpretive errors of their origin and formation. Thus, this project set out to determine the genesis and evolution of these mounds and also to identify the cultural occupation and transformation of natural landforms found in the area. In this article, natural and anthropogenic systems and processes were identified and characterized through the application of proxy record analysis (i.e., sediment composition, stratigraphy, micromorphology, silica bodies and chronological analysis) at the Los Tres Cerros archaeological locality in the Upper Delta of the Paraná River of Victoria County, Entre Ríos Province, Argentina. This analysis allowed for the recognition of natural anthropogenic interfaces, such as the "pre-mound" occupation as well as evidence of cultural activities such as mound construction, between 1,000 and 500 14 C years BP. These findings were integrated into current research on the variability of mound construction during the Late Holocene in the lowlands of South America.

Geological, geomorphological and soil maps provide important information on the substrate as well as on the past and present physical landscape. For the intensely studied Netherlands coastal plain and Rhine-Meuse delta, many such map datasets have been compiled over the last two centuries. These mapping materials comprise older and younger legacy datasets, often fragmented over regions. They have been compiled within various research traditions and by various parties, involving geologists, soil scientists, geomorphologists and landscape archaeologists. The maps and datasets summarise overwhelming amounts of underlying data accumulated over the last few centuries, and are therefore valuable for reconstructing past landscapes. Digital-infrastructure developments have enhanced possibilities for recombining existing and new data over the last few decades, e.g. through GIS solutions such as palaeogeographical base maps, from which multiple derived map products can be generated. Integration of thematic information from various source maps and underlying data is needed to use the accumulated data diversity to its full potential and to answer applied and fundamental scientific questions. Using diverse information to compile or update maps, however, requires awareness of legacy surveying strategies and the state of knowledge at the time the original data and maps were produced. This paper reviews the soil, geological and geomorphological mapping traditions. We evaluate their products, underlying data and the reasoning behind their compilation, focusing on their use in conventional and digital palaeogeographical mapping. This helps get the most out of large quantities of legacy and modern data, a major challenge for surface and substrate digital mapping in the big-data era.

The Holocene evolution of the Ombrone River delta has been investigated using morphological and sedimentological evidence. The delta had a lagoon-like prehistoric evolution, while seawards the growth occurred mainly in historical times. The data obtained, together with the available historical and archeological documentation, enable a quantitative evaluation of the volume of the emerged part of the delta to be made. Moreover, for the apical area, it has been possible to calculate the annual average increase in the volume of deposition during Etruscan and Roman times, as well as during the Middle Ages and since the Renaissance up to now. It has been possible to estimate the periods during which wind exerted a more important role in shaping the delta morphology. The volume of sediments deposited during the last 6000 years has been estimated at 1766Á10 6 m 3 . A combination of climatic conditions, littoral dynamics and human action appears to have driven the dynamics of the delta growth, which, however, was not continuous, but active especially during the last 3000 years. During this period, about the 80% of the whole delta volume seems to have deposited. High rates of sedimentation occurred between the 16th and the 19th centuries (a cold and moist period coinciding with the Little Ice Age), when the delta took the typical shape of microtidal wave-dominated deltas. D

TNO Geological Survey of the Netherlands systematically produces 3D voxel models for answering subsurface related questions. The unique combination of vast amounts of borehole data and the voxel-based approach makes the models valuable new sources for exploring the Quaternary fluvial record. The latest generation of 3D voxel models (GeoTOP) schematises the shallow subsurface of the  Netherlands in millions of voxels each measuring 100 by 100 by 0.5 m up to a depth of 50 m below sea level. The GeoTOP model was used to perform a 3D spatial trend analysis on channel belt lithology, sand grain-size and architectural characteristics in the Holocene Rhine-Meuse delta. An analysis of the coarse-sand and fine-sand fractions shows clear spatial trends that relate to downstream changes in gradient, reworking of older sediments and tidal influence. Channel deposit proportions show an almost linear downstream decrease with an average value of about 0.5% per km. Our data can act as an important constraint for hydrocarbon reservoir modelling where this type of information is often only sparsely available.

The growth of Chilia deltaic lobes reflects a drastic reorganization of the Danube delta that accompanied its rapid expansion in the late Holocene. Using new cores collected at the apices of the two older Chilia lobes together with historical maps and satellite photos, we find that a partial avulsion since ∼1500 years BP led to a gradual rejuvenation of the Chilia distributary, which successively infilled a lake, a lagoon, and then constructed an open coast lobe at the Black Sea coast. The Chilia branch became the largest Danube distributary reaching its maximum sediment load in the last 300 years as the southernmost St. George branch lost its previous dominance. Here we propose that the intensive deforestation of Danube&#39;s lower watershed leading to this delta reorganization has historical cultural causes: an increase in sheep and timber demand associated to the Ottoman Empire expansion in Eastern Europe followed by the adoption of maize agriculture as a result of the Columbian ...

In archaeology, environmental history all too often focused on the individual settlements and on the economic use of their immediate environment. This view fails to acknowledge the importance of other actors (e.g. animals, plants, waters) interacting with humans. Outside the settlements, the traces of humans and these other actors are entangled and become difficult to discern. This is especially true for processes in deltas, which are inherently dynamic, complex, short-lived and fragmented. The life and activities of humans in such areas can only be properly assessed if the habitat as a whole with all its actors is understood and a long-term perspective is adopted.
Due to intensive construction work in the Lorze Delta since the 1980s, the archaeological department of Canton Zug has carried out a number of excavations. However, only now has the basic information about the sites (e.g. location, sediments and dating) been more broadly compiled and the results of the different studies been collated. This has led to ground-breaking insights into the cultural and natural interactions in the catchment area of the Lorze River.
In the early stages of the Lorze Delta during the Late Glacial and Early Holocene, after the melting of the Reuss Glacier, the only just populated landscape was characterised by unstable geological conditions. When analysing Neolithic and Bronze Age pile dwellings, understanding the Lorze Delta’s formation is a prerequisite for appreciating the sites’ location. In the alluvial fan, long-term changes in human and riverine activity from the Bronze Age to the Middle Ages can be detected. Today, human impact instead of geological processes write the delta’s story: the river course has been diverted to give way for a motorway while the delta itself has been altered artificially.

Celem niniejszego artykułu jest poznanie cech litologicznych i geochemicznych osadów postglacjalnych występujących w dnie misy Zalewu Szczecińskiego, a także utworów akumulowanych współcześnie w tym akwenie. Uzyskane informacje stanowią podstawę dla rekonstrukcji środowisk sedymentacyjnych i warunków akumulacji osadów panujących na obszarze dzisiejszego Zalewu Szczecińskiego
od schyłku ostatniego zlodowacenia do czasów współczesnych.