Sedimentary Evolution of Estuaries and Coastal Plains: Subsidence, Sediment Loss and Aquifer Hazards

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Oceans and Coastal Zones".

Deadline for manuscript submissions: closed (31 October 2021) | Viewed by 15959

Special Issue Editors

Department of Engineering, University of Campania L.Vanvitelli, Via Roma 9, 81031 Aversa, Italy
Interests: sedimentology; coastal morphology; coastal evolution; quaternary; alluvial-delta systems; landscape evolution; geographic information systems
Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, China
Interests: marine sediment dynamic; inter-tidal flat; saltmarshes; mangrove; organic carbon cycle; heavy metal pollution; sedimentary records; suspended particulate matter; estuarine geomorphology
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Estuaries and the related coastal plains are delicate sedimentary settings which evolve under the effect of different hydrodynamic ranges and sediment load from rivers, in turn controlled by relative sea level rise.

The regime of accelerating sea-level rise forecasted by the IPCC (2013) suggests that many coastal plains and related marshes and/or tidal flats may soon cross a threshold and become threatened by geological hazards such as aquifer salinization, inundation of low lands, coastal erosion, and increased vulnerability to flooding and storm surges. On the other hand, subsidence rates, which reflect regional and local tectonic effects, can be greatly enhanced by consolidation of the Holocene sedimentary strata due to creep, thus resulting in an additional vertical movement at ground surface. Moreover, many coastal areas are also suffering from a sediment loss of billions m3/a due to anthropic extraction from river basins. The consequence of such a deficit in the sediment budget is the progressive destruction of salt marshes and tidal flats, coupled with coastal erosion.

This Special Session aims to explore the causes and consequences of coastal hazard, along with subsidence, coastal erosion, and aquifer salinization, by taking into account the variety of independent drivers and focusing on the role of the hydrodynamics processes, the sedimentary architecture, and the related geotechnical characteristics of estuarine and coastal settings.

We encourage studies addressing a wide range of spatial and temporal scales and applying state-of-the-art methodologies. Interdisciplinary studies are strongly encouraged, as they provide the basis for a sustainable management.

Prof. Dr. Daniela Ruberti
Prof. Dr. Ai-jun Wang
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • estuaries
  • coastal plains
  • sedimentary dynamics
  • sedimentary architecture
  • aquifer salinization
  • coastal erosion
  • subsidence
  • coastal hazards

Published Papers (7 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Other

18 pages, 4763 KiB  
Article
The Holocene Evolution of the Volturno Coastal Plain (Northern Campania, Southern Italy): Implications for the Understanding of Subsidence Patterns
Water 2021, 13(19), 2692; https://doi.org/10.3390/w13192692 - 28 Sep 2021
Cited by 10 | Viewed by 1740
Abstract
In the Mediterranean area, several alluvial coastal plains, developed after the Holocene transgression, are affected by subsidence. The Volturno alluvial-coastal plain, along the eastern Tyrrhenian Sea (southern Italy) is characterized by subsidence rates determined through InSAR data analysis and ranging between 0 and [...] Read more.
In the Mediterranean area, several alluvial coastal plains, developed after the Holocene transgression, are affected by subsidence. The Volturno alluvial-coastal plain, along the eastern Tyrrhenian Sea (southern Italy) is characterized by subsidence rates determined through InSAR data analysis and ranging between 0 and <−20 mm/year in an area of about 750 kmq across the Volturno River. Inside this area, the pattern of subsidence shows sites with apparently anomalous localized subsidence. To understand the driving mechanisms of this process, a lithostratigraphic reconstruction was provided focusing on the spatial distribution of the horizons considered weak by a geotechnical point of view; then, the subsidence map was overlain spatially with geological data in a Geographic Information System (GIS) environment. The spatial analysis highlighted the major ground deformation occurring within the outer boundary of the incised paleo-valley, corresponding to the Holocene alluvial/transitional filling that overlies a compaction-free Pleistocene basement. Inside this general trend, differential compaction was detected corresponding to the thick occurrence of clay and peat deposits, suggesting that the subsidence rate registered in the plain are due in part to the consolidation of primary settlements of soft and compressible soils that characterize the subsoil of these areas, and in large part to the secondary consolidation settlements. Full article
Show Figures

Figure 1

10 pages, 2752 KiB  
Article
Seasonal Variation and Ecological Risk Assessment of Heavy Metal in an Estuarine Mangrove Wetland
Water 2021, 13(15), 2064; https://doi.org/10.3390/w13152064 - 29 Jul 2021
Cited by 9 | Viewed by 2171
Abstract
Potential toxic metal pollution in mangroves has attracted extensive attention globally; however, the seasonal variation of potential toxic metals in mangrove wetlands is still poorly understood. Herein, we investigated the variation of content as well as chemical speciation of typical metals (Pb, Cr, [...] Read more.
Potential toxic metal pollution in mangroves has attracted extensive attention globally; however, the seasonal variation of potential toxic metals in mangrove wetlands is still poorly understood. Herein, we investigated the variation of content as well as chemical speciation of typical metals (Pb, Cr, Zn and Cu) in the sediments from the Zhangjiang Estuary mangrove wetland, China. The potential risk of metal contamination was also investigated. Compared to the wet season, we found that sediment metal content was higher in the dry season. Mangrove sites show accumulated significant metals than does the mudflat both in wet and dry seasons. Geo-accumulation (Igeo) shows moderate pollution, probably because of the dilution as result of runoff and tidal hydrodynamics in the wet season. Increased concentrations of all metals in the acid-soluble fraction and decreased metal contents in the residue fraction were found in the dry season. Risk assessment indicated that the concentrations of Pb poses a higher environmental risk in the dry season. These results can increase awareness of metal pollution in the dry season and provide information for potential toxic metal management in mangrove wetlands. Full article
Show Figures

Figure 1

19 pages, 11591 KiB  
Article
Quaternary Evolution of Coastal Plain in Response to Sea-Level Changes: Example from South-East Sicily (Southern Italy)
Water 2021, 13(11), 1524; https://doi.org/10.3390/w13111524 - 28 May 2021
Cited by 13 | Viewed by 2356
Abstract
During a cycle of sea-level variation, coastal environments develop in different position of the continental shelf following seaward and landward shift of the coastline. They vary widely in character, reflecting the wide range of process-regimes that are brought about during the different stages [...] Read more.
During a cycle of sea-level variation, coastal environments develop in different position of the continental shelf following seaward and landward shift of the coastline. They vary widely in character, reflecting the wide range of process-regimes that are brought about during the different stages of sea-level variations. Within this scenario, the morphology of continental shelves, mainly resulting from the combined effect of tectonic activity and eustatism, plays an important role in controlling the features and the preservation of coastal environments. Coastal deposits formed along continental shelves in the past, during different stages of sea-level changes, consist of discontinuous and thin depositional bodies, thus their reconstruction can be best carried out through the interpretation of high-resolution seismic data. Such a research approach is adopted in the present study to investigate a portion of the continental shelf of the southernmost sector of SE Sicily, in the offshore of Marzamemi village (Syracuse). The interpretation of high-resolution “Sparker” profiles allowed us to reconstruct the evolution of alluvial and lagoonal environments, established on a substratum of Pliocene or more ancient marine deposits, with the detection of several seismic units and unconformity surfaces, which have been related to alternating sedimentation and erosional processes, depicting the sea-level change framework of glacial-interglacial phases, from the late Pleistocene onward. Full article
Show Figures

Figure 1

18 pages, 7719 KiB  
Article
Differences in the Sulfate–Methane Transitional Zone in Coastal Pockmarks in Various Sedimentary Environments
Water 2021, 13(1), 68; https://doi.org/10.3390/w13010068 - 31 Dec 2020
Cited by 4 | Viewed by 2317
Abstract
Different types of pockmarks, including single pockmarks, circular pockmarks, elongated pockmarks, chain-type pockmarks, and compound pockmarks, were identified in coastal areas around Fujian, China. The sediments associated with pockmarks were mainly silty clay to clay, with a small quantity of silt with fine [...] Read more.
Different types of pockmarks, including single pockmarks, circular pockmarks, elongated pockmarks, chain-type pockmarks, and compound pockmarks, were identified in coastal areas around Fujian, China. The sediments associated with pockmarks were mainly silty clay to clay, with a small quantity of silt with fine sand. The sulfate content in the pore water in the sedimentary layers associated with pockmarks decreased with depth from the surface, whereas the free methane content increased with depth. The interaction between sulfate and methane is well known, but differences in the sulfate–methane transitional zone (SMTZ) were observed in different areas with different hydrologic characteristics. The sedimentary SMTZ of the offshore Zhe-Min mud wedge was shallow, at 50–70 cm below the seafloor. The sedimentary SMTZ was moderately deep (90–115 cm) in the central bay area and deep (180–200 cm) in the sandy area offshore. This variability in SMTZ depth reflects different amounts of free methane gas in the underlying formations, with a shallower SMTZ indicating a higher free methane content. The free methane had δ13C values of −26.47‰ to −8.20‰ and a biogenic hybrid genetic type. The flux of sedimentary gas from the pockmark surfaces, calculated according to Fick’s formula, was 2.89 to 18.85 L/m2·a. The shape, size, and scale of the pockmarks are directly related to the substrate type and the gas production of the underlying strata and thus vary with the sedimentary environment and development stage. Therefore, different types of pockmarks, in various phases of development, are associated with different sedimentary and dynamical conditions. A single circular pockmark is formed by a strong methane flux. As the intensity of methane flux weakens, the pockmark becomes elongated in the direction of the water flow because of long-term erosion induced by regular hydrodynamic forces. Finally, under a weak intensity of methane flux and the influence of complex hydrodynamic conditions, pockmarks merge to form large-scale compound pockmarks. Full article
Show Figures

Figure 1

18 pages, 4819 KiB  
Article
Distribution of Carbon and Nitrogen as Indictors of Environmental Significance in Coastal Sediments of Weizhou Island, Beibu Gulf
Water 2020, 12(11), 3285; https://doi.org/10.3390/w12113285 - 23 Nov 2020
Cited by 3 | Viewed by 2318
Abstract
Carbon and nitrogen contents and their isotopic components, and AMS (Accelerator Mass Spectrometry) radiocarbon dating ages, were measured for 57 coastal sediments from Weizhou Island to analyze the distribution of total inorganic carbon (TIC) and its carbon and oxygen isotopic components (δ [...] Read more.
Carbon and nitrogen contents and their isotopic components, and AMS (Accelerator Mass Spectrometry) radiocarbon dating ages, were measured for 57 coastal sediments from Weizhou Island to analyze the distribution of total inorganic carbon (TIC) and its carbon and oxygen isotopic components (δ13Ccarb and δ18Ocarb), total organic carbon (TOC) and total nitrogen (TN) contents and their stable isotopic components (δ13CTOC and δ15NTN), and their environmental significance. The results showed that the oldest age of coastal sediments on Weizhou Island was 2750 cal. a BP (before present), and the average TIC contents of cores A1, A2, B1, C1, and D1 in the intertidal zone were all greater than 5%, where δ13Ccarb and δ18Ocarb were enriched, whereas the TIC contents in cores A3, C2, and D2 of the supra-tidal zone were low, where δ13Ccarb and δ18Ocarb were depleted. Moreover, TIC decreased sharply, 4.95% on average, to close to zero from the estuary to the upstream region in the C1-C2 section. The average C/N ratio was 7.02, and δ13CTOC and δ15NTN were between −14.96‰ and −27.26‰ and −14.38‰ and 4.12‰, respectively. These measurements indicate that the TIC in coastal sediments mainly came from seawater. Cores A1, A2, and B1 in the northern intertidal zone exhibited organic terrestrial signals because of C3 and C4 plant inputs, which indicates that the important source on the northern coast of Weizhou Island came from island land but followed the decrease in C3 plants. The lacustrine facies deposits were mainly distributed in the upper reaches of the river, the northern coastline was advancing toward the sea, and part of the southwestern coastal sediments rapidly accumulated on the shore under the influence of a storm surge. The relative sea level of the Weizhou Island area has continuously declined at a rate of approximately 2.07 mm/a, using beach rock as a marker, since the Holocene. Full article
Show Figures

Figure 1

22 pages, 6134 KiB  
Article
Satellites HY-1C and Landsat 8 Combined to Observe the Influence of Bridge on Sea Surface Temperature and Suspended Sediment Concentration in Hangzhou Bay, China
Water 2020, 12(9), 2595; https://doi.org/10.3390/w12092595 - 17 Sep 2020
Cited by 8 | Viewed by 1895
Abstract
We analyzed the influence of a cross-sea bridge on the sea surface temperature (SST) and suspended sediment concentration (SSC) of Hangzhou Bay based on landsat8_TIRS data and HY-1C data using an improved single window algorithm to retrieve the SST and an empirical formula [...] Read more.
We analyzed the influence of a cross-sea bridge on the sea surface temperature (SST) and suspended sediment concentration (SSC) of Hangzhou Bay based on landsat8_TIRS data and HY-1C data using an improved single window algorithm to retrieve the SST and an empirical formula to retrieve the SSC. In total, 375 paired sampling points and 70 transects were taken to compare the SST upstream and downstream of the bridge, and nine transects were taken to compare the SSC. The results show the following. (i) In summer, when the current flows through the bridge pier, the downstream SST of the bridge decreases significantly, with a range of 3.5%; in winter, generally, the downstream SST decreases but does not change as obviously as in summer. The downstream SSC increases obviously. (ii) The range of influence of the bridge pier on the downstream SST is about 0.3–4.0 km in width from the bridge and that on the downstream SSC is approximately 0.3–6.0 km. (iii) When the current flows around the pier, a portion of the flow is dispersed in upward and downward directions; the downward flow generates local scour. When the scouring at the front end of the pier stops, the upward flow behind the pier brings the sediment and the bottom cold water downstream, causing the downstream SST to decrease and the SSC to increase. (iv) The other portion passes around the pier, which generates a wake vortex. Once a wake vortex is released, a low-pressure center appears, sucking the sediment and the bottom cold water to the downstream sea surface, reducing the downstream SST and raising the SSC. (v) The range of reduction of the SST downstream of the bridge is shorter than the range of increase in the SSC. This is because the wake vortices have an effect in the 0.3–4.0 km downstream but not in the 4.0–6.0 km. Therefore, the SST and SSC are affected within the range of 0.3–4.0 km by wake vortices, while in the 4.0–6.0 km region, the SSC is still high due to the transport of sediment by currents. Full article
Show Figures

Graphical abstract

Other

Jump to: Research

12 pages, 2049 KiB  
Technical Note
Calibrations of Suspended Sediment Concentrations in High-Turbidity Waters Using Different In Situ Optical Instruments
Water 2020, 12(11), 3296; https://doi.org/10.3390/w12113296 - 23 Nov 2020
Cited by 7 | Viewed by 2426
Abstract
In environments of high suspended sediment concentration (SSC > 1 kg/m3), efficient measurements of SSC through accurate calibration relationships between turbidity and SSC are necessary for studies on marine sediment dynamics. Here, we investigated the performance of three types of optical [...] Read more.
In environments of high suspended sediment concentration (SSC > 1 kg/m3), efficient measurements of SSC through accurate calibration relationships between turbidity and SSC are necessary for studies on marine sediment dynamics. Here, we investigated the performance of three types of optical instrument (OBS-3A, AQUAlogger 310TY, and RBRsolo3Tu with Seapoint sensor) in observations carried out at the middle of the Jiangsu coast, China. These instruments were calibrated in the lab using the water and suspended sediment samples collected from the observation site. It was found that both the calibration curves of OBS-3A and RBRsolo3Tu have an inflection point (at SSC of ca. 15 kg/m3 for OBS-3A and ca. 2 kg/m3 for RBRsolo3Tu), on either side of which turbidity increases (the left side) or decreases (the right side) with the increasing SSC. Only under SSCs smaller than the inflection point can OBS-3A and RBRsolo3Tu be applied to continuous SSC measurements at a fixed point. However, the turbidity output of AQUAlogger 310TY has always a positive correlation with SSC, which applies for SSC up to 40 kg/m3; thus, three fluid-mud events are quantified during this observation. AQUAlogger 310TY has important prospects for field applications in high-SSC environments. Full article
Show Figures

Figure 1

Back to TopTop