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This article studies the migration and settlement laws of backflow proppants after fracturing tight sandstone. This paper proposes a fitting method based on a multi-task learning network to address the issue of interference from multiple physical parameters during the transport and settlement processes of proppants. This method can effectively handle multi-dimensional interference factors and fit the mapping logic of multiple engineering parameters to transport patterns through the continuous correction of multi-layer networks. We first introduce the characteristics of tight sandstone reservoirs and their important value in mining, as well as the status of current research on the migration and settlement laws of proppants at home and abroad. Based on this, we then deeply analyze the sedimentation rate model of proppants in tight sandstone backflow and the equilibrium height of proppants under multiple factors of interference while considering the distribution characteristics of proppants. In order to more accurately simulate the transport and settlement laws of proppants, this paper introduces a multi-task learning network. This network can comprehensively consider multi-dimensional parameters, learn the inherent laws of data through training, and achieve accurate fitting of the transport and settlement laws of proppants. This study trained and tested the model using actual production data, and the results showed that the proposed model can fit the input–output relationship well, thus effectively supporting the study of proppant transport and settlement laws. [ABSTRACT FROM AUTHOR]

Flash floods can carry substantial sediment, posing significant sedimentation hazards in hilly cities. The sedimentation hazard map can reproduce the sediment thickness and extent of an extreme events scenario, playing an important role in sediment risk management. However, current research primarily focuses on modeling the inundation area and depth of floods, while studying sedimentation hazard caused by flash floods in urban areas remains insufficient. This paper aims to address this gap by utilizing a numerical model that simulates hyperconcentrated flow in hilly urban areas using the two‐dimensional hydro‐sediment‐morphological model to compile the cumulative sedimentation hazard map. The model, built upon the open‐source TELEMAC‐MASCARET framework, incorporates Zhang Hongwu's formula to simulate sediment‐carrying capacity, particularly suitable for hyper‐sediment concentration near the riverbed. This paper uses the data of extreme flash flood events in the Wuding River basin in 2017 to simulate and compile the cumulative sedimentation hazard map. The hazard map delineates the sedimentation hazard extent and level attributable to overbank floodplain sedimentation. Notably, the sediment thickness is highest in areas near the levees on both sides of the Dali River. Moreover, the map illustrates the extent of channel erosion resulting from hyperconcentrated floods, which could jeopardize bank stability. [ABSTRACT FROM AUTHOR]

Purpose: Verification monitoring was performed over five years following the sediment remediation of the Buffalo River Area of Concern (AOC), New York, USA. Monitoring results were compared with surface sediment cleanup goals to determine whether natural sedimentation allowed the AOC to achieve long-term remedial goals without the placement of cover material to manage dredge residuals. Material and methods: Monitoring was conducted two years and five years following sediment remediation and included: 1) bathymetric surveys to understand sediment stability and deposition rates, and 2) the analysis of surface sediment samples for four primary chemicals of concern (COCs), including polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), lead, and mercury, to compare surface sediment concentrations over time with site-specific sediment remedial goals. Results and discussion: The monitoring results demonstrated the following: 1) sedimentation is occurring, 2) a stable depositional environment is present throughout the Buffalo River AOC, and 3) measurable reductions in sediment concentrations were observed for PAHs, PCBs, lead and mercury in the newly deposited sediment. By Year 5, surface sediment chemistry results generally achieved the remedial goals throughout the Buffalo River AOC. Conclusion: Monitored natural recovery (MNR) was effective in physically isolating dredge residuals in the Buffalo River AOC, following sediment removal. This post-dredging MNR approach met the surface sediment remedial goals in most areas, resulted in a protective and cost-effective project by not requiring the placement of clean cover material in the dredge areas, and was an environmentally sustainable strategy by eliminating the need to collect, transport, and place millions of kilograms of clean quarried material in the river. [ABSTRACT FROM AUTHOR]

Purpose: This study aims to improve the quality, efficiency, and economic benefits of using ultrafine phosphate tailings in mining backfill operations. Method; Based on the physicochemical properties of phosphate tailings, this study investigates the optimal conditions for their flocculation and sedimentation by controlling flocculant dosage and feed concentration. Additionally, it examines the effects of varying solid concentrations and sand-to-cement ratios on the flowability of the backfill slurries and the mechanical properties of the backfill mass. Result and Conclusion; The results indicate that the optimal feed concentration for flocculation and sedimentation of ultrafine phosphate tailings is 10% .With a polyacrylamide dosage of 25 g/t, the underflow [ABSTRACT FROM AUTHOR]

Due to the significant sedimentation and anthropogenic pressures, the Kashmir Himalaya lakes (Dal, Wular, Manasbal) located within and in the vicinity of urban settlements are experiencing massive degradation. The unique climate, geographic setting, and rock degradation owing to the tectonic uplift of the area, contribute to increased sedimentation in these lakes. The sewage and other anthropogenic pressures have also increased various minerals including nitrogen influx in these lakes. Total organic carbon levels in the Dal Lake are high and range from 2.72% to 25.12%, with nitrogen levels ranging from 0.92% to 9.81%. The total organic carbon of Wular and Manasbal Lakes ranges from 0.83% to 4.52%, and 3.11% to 13.74% with nitrogen ranging from 0.06% to 0.5% and 0.20% to 1.96%, respectively. The estimated sedimentation rates for the Wular, Manasbal, and Dal Lakes are 0.125 cm/yr, 0.44 cm/yr, and 0.93 cm/yr. Given these factors and the geographic setting of Kashmir Himalaya, it is believed that under the sustained threat of climate change and anthropogenic pressure, mitigation strategies to control sedimentation and pollution are unavoidable for the long‐term survival of these valuable ecosystems. This review examines contributing factors, explores potential consequences, and proposes mitigation measures, to save these important aquatic ecosystems from further deterioration. [ABSTRACT FROM AUTHOR]

River channels are maintained by coordination between flow hydraulics, sediment supply, riparian vegetation, and sediment transport. This coordination is challenging to understand in natural flow regimes, where climatic and environmental drivers produce episodic flood and sediment supply events. To better understand the response of channels to flood sequences, we have undertaken laboratory flume experiments on sediment storage and export across a sequence of alternating hydrographs. Our experiments indicate that accumulated sediment storage before floods predicts sediment transport during floods, with sediment storage depletion during floods causing a nonlinear variation of sediment‐transport rates through time. Likewise, sediment storage between floods follows a growth‐to‐saturation pattern, whereby the sediment transport gradually increases toward the sediment feed rate depending on the occupation of available sediment storage zones. To describe these non‐linear variations, we developed a mathematical model which represents sediment transport and storage as a coupled dynamical system. This work highlights the crucial role that within‐channel sediment storage and its history play in determining sediment export in rivers. Plain Language Summary: The amount of sediment moving in a river channel largely determines its stability during floods; therefore, numerous ecological and engineering applications utilize predictions of sediment‐transport rates in rivers. Most prediction models assume that the force of the water and the size of sediment are the main variables needed to predict sediment‐transport rates. This implies that no information about the historical patterns of sedimentation in the channel is required to predict the amount of moving sediment. To test this implication, we conducted laboratory experiments on sediment transport across a sequence of floods. In contrast to existing prediction methods, we determined that the amount of sediment accumulated in a channel is a leading predictor of sediment transport both between and during floods. We characterized this dependence of sediment transport on the history of sediment storage and described it with a mathematical model. This work helps us better understand how floods affect the stability of river channels. Key Points: Sediment‐transport rates across flood sequences are largely predicted by the sediment storage accumulated in periods between floodsCoupling between sediment transport and storage generates non‐linear temporal variations of mean sediment‐transport ratesHistorical sediment transport and supply trends therefore control channel stability in conjunction with present‐time flow and sediment characteristics [ABSTRACT FROM AUTHOR]

Many tidal marshes have been lost by past land use changes, but are nowadays increasingly restored and created to provide valuable ecosystem services such as nature‐based flood and erosion protection along estuarine shorelines. To be functional for flood and shoreline erosion protection, restored and created tidal marshes should develop erosion resistant sediment beds. Here, we investigated which factors drive the spatial variations in sediment strength and erosion resistance in a developing tidal marsh restoration site. Our results show that decreasing tidal inundation frequency, decreasing sedimentation rate, and better drainage led to stronger consolidation in deeper sediment layers. This consolidation resulted in greater sediment strength, quantified here by shear strength and penetration resistance. Generally, sediment strength was greater when sediment had higher bulk density, while a higher water and fine fraction (= clay and silt) content decreased sediment strength. Overall, all measurement locations were relatively erosion resistant, likely caused by the dense root network and cohesive sediment. To restore or create resilient tidal marshes for nature‐based flood and shoreline erosion protection, we should thus aim for sites with relatively low tidal inundation frequency, moderate sedimentation rates, and cohesive sediment mixtures of clay, silt, and sand, which are well drained and have potential for vegetation establishment. These conditions have a high likelihood of resulting in restored or created tidal marshes that contribute to nature‐based flood and shoreline erosion protection. [ABSTRACT FROM AUTHOR]

Sedimentary landforms on Earth and other planetary bodies are built through scour, transport, and deposition of sediment. Sediment connectivity refers to the hypothesis that pathways of sediment transport do not occur in isolation, but rather are mechanistically linked. In dryland river systems, one such example of sediment connectivity is the transport of fluvially deposited sediment by wind. However, predictive tools that can forecast fluvial‐aeolian sediment connectivity at meaningful scales are rare. Here we develop a suite of models for quantifying the availability of river‐sourced sediment for aeolian transport as a function of river flow, wind regime, and land cover across 168 km of the Colorado River in Grand Canyon, USA. We compare and validate these models using topographic changes observed over 10 years in a coupled river sandbar‐aeolian dunefield setting. The models provide a path forward for directly linking fluvial hydrology with the management and understanding of aeolian landscapes. Plain Language Summary: Landscapes on Earth are built from sediment, which is deposited by a variety of processes, especially water and wind. In rivers located in dry regions, sediment is deposited by flowing water during river floods. Once this sediment dries, it is often then moved by wind across the landscape. Although we frequently observe this sediment connectivity between water and wind, we are not currently able to predict when and where windblown transport of river‐deposited sediment may occur. We used maps of sand in Grand Canyon along 168 km of the Colorado River, along with records of river flow, wind speed, and vegetation cover, to develop four models that predict how much sediment is available for wind to move. We compared the results of these models to actual windblown sediment transport at a study site in Grand Canyon, finding that when models predicted more sand was available at the site, we also observed more landscape changes there which were due to wind. Our research makes it possible to understand how changes in river flows affect the amount of sediment moved by wind. Key Points: We developed four methods for modeling the extent of exposed, bare sand available for windblown transport in river valleysOur models employ data on river flow, land cover, wind velocity, and vegetation to predict exposed, bare sand extent at corridor scalesWhere models predict increased areal extent of bare sand, we also observe a greater volume of topographic changes driven by wind [ABSTRACT FROM AUTHOR]

Hydrological drought is a pervasive and reoccurring challenge in managing water resources. Reservoirs are critical for lessening the impacts of drought on water available for many uses. We use a novel and generalized approach to identify periods of unusually low reservoir storage—via comparisons to operational rule curves and historical patterns—to investigate how droughts affect storage in 250 reservoirs across the conterminous U.S. (CONUS). We find that the maximum amount of water stored in reservoirs is decreasing, and that periods of unusually low storage are becoming longer, more severe, and more variable in (a) western and central CONUS reservoirs, and (b) reservoirs with primarily over‐year storage. Results suggest that reservoir storage has become less reliable and more vulnerable to larger deviations from desired storage patterns. These changes have coincided with ongoing shifts to the hydroclimate of CONUS, and with sedimentation further reducing available reservoir storage. Plain Language Summary: Drought in water systems is a major challenge in managing water resources. Reservoirs are important as they can lessen the impacts of drought on water availability for many users. However, they are impacted by drought as well. We use a novel and generally applicable method to identify when reservoir storage is unusually low, potentially from drought, at 250 reservoirs across the conterminous U.S. We find that the maximum amount of water stored in reservoirs is decreasing across the U.S. We also find that periods of unusually low storage are becoming longer and more severe in western and central U.S. regions as well as for certain types of reservoirs. This suggests that reservoir storage may be less reliable and more vulnerable to extreme conditions and may be further impacted by changing climate and hydrology across the U.S. and by sediment building up behind reservoirs. Key Points: Low‐storage periods are longer, more severe, and more variable in over‐year storage reservoirs and in the western and central CONUSLonger periods of low storage for some regions in recent years suggests decreased reservoir reliability in a changing hydroclimateMaximum annual storage is also declining across CONUS, furthered by storage losses from sedimentation [ABSTRACT FROM AUTHOR]

The Zhongsha Platform is the largest modern isolated carbonate platform of around 8600 km2 in the South China Sea, providing a unique case study for sedimentary processes in pure carbonate settings. High-resolution multibeam bathymetric data, two-dimensional seismic profiles, and surface sediment cores are utilizes to reveal the initiation and evolution of submarine canyons on the northeastern slope of the Zhongsha Platform. Three submarine canyons are revealed within the survey area that incise the slope at water depths between 600 and 4100 m. C1 presents a linear pattern, whereas C2 and C3 exhibit dendritic morphologies. A large-scale scalloped collapse has deeply excavated the platform margin and slope. Within this catastrophic failure, C2 originated in a northeastward orientation and subsequently converted to an eastward direction with a length of 54.8 km. It is distinguished by the erosion of numerous tributaries in the upper course, the transition of flow direction in the middle course, and the presence of retrogressive landslides in the lower course. Slope landslides extend eastward from middle-lower slope towards the oceanic basin at water depths ranging from 2300 to 4200 m. A series of scarps and immature canyons have developed with escarpments showing pronounced relief at the landslide heads. The triggering mechanisms of platform margin collapses and slope landslides are attributed to sediment aggradation, slope oversteepening, gravity flows, relative sea-level changes, surface monsoon currents, and deep cyclonic circulation. The canyon evolution is explained through four stages: Inception stage, sediment instability on platform margin and slope-toe; Expansion stage, the presence of platformmargin collapses and slope landslides; Development stage, the initiation of submarine canyons eroded by gravity flows with downslope and retrogressive erosion; Present stage, the upper slope canyon incised into the landslide area and ultimately integrated with the lower slope canyon, creating an elongated modern canyon. This work contributes to enhance our understanding of the detailed morphology, transport processes, and triggering mechanisms of submarine canyons in the pure carbonate systems. [ABSTRACT FROM AUTHOR]

In order to explore the sediment deposition characteristic of ecological riverbanks associated with vegetation restoration in the deep waterway regulation scheme of Yangtze River, two kinds of typical ecological riverbanks and a traditional riprap riverbank (TRR) in engineering areas were investigated. The vegetation community characteristics, sediment aggregate compositions, nutrient contents, total organic carbon (TOC), sediment microbial biomass carbon (MBC), sediment microbial biomass nitrogen (MBN), and sediment microbial biomass phosphorus (MBP) were determined. The results indicated that the ecological restoration effect of the lattice gabion ballasted vegetation mat riverbank (LGBVR) was best, followed by the mesh grid riverbank (MGR), and that of the TRR was relatively poor. In different ecological riverbanks, the sediment aggregated compositions were not significantly varied. The sediment contents of NH4+-N, available phosphorus (AP), and TOC in ecological riverbank areas were relatively higher than those of the TRR. In the LGBVR, the sediment contents of MBC were relatively higher than those of the others. The sediment deposition characteristics and ecological restoration effects in the study area should be monitored for a long time. [ABSTRACT FROM AUTHOR]

Tidal flats, crucial for biodiversity and ecosystem services, are facing significant alterations due to human activities such as reclamation. In South Korea, over 65% of tidal flats have been reclaimed since the 1970s, resulting in morphological changes and altered sediment transport dynamics. This study investigates sediment transport processes in the artificial Aam tidal channel, created as part of the megacity development project in Incheon, Korea. Using data from Acoustic Doppler Current Profiler and Vector instruments deployed in 2019 and 2021, we analyzed tidal asymmetry, current velocities, shear stress, and suspended sediment concentration. Our results reveal a pronounced tidal asymmetry influencing sediment transport, with ebb-dominant currents near the channel entrance and flood-dominant currents in the interior. We observed significant sediment deposition in the landward section of the channel, driven by tidal mixing asymmetry and rainfall events. These findings highlight the complex interactions between artificial structures and natural sediment dynamics, informing future coastal development and management strategies. [ABSTRACT FROM AUTHOR]

The investigation results of granulometric composition, zeta potential, sedimentation stability, and viscosity of some water-coal suspensions made of Ukrainian coal from the “Stepova” mine, Lviv-Volyn region, are reported. The most effective granulometric composition of the water-coal suspension consisting of the rough and fine fractions is found from the analysis of the abovementioned physicochemical characteristics of the suspensions. Based on the complex investigation of the zeta potential of the dispersed phase particles, viscosity, and sedimentation stability of the suspensions, it was established that the best technological effectiveness can be expected for the suspensions containing 60% of the rough fraction (sized between 100 and 250 µm) and fine particles sized between 20 and 40 µm. In such systems, the particles form a quasi-stable structure, where the lower-charged small particles are located in the interparticle space between the highly charged bigger particles. All particles bear the same charge, increasing the system’s sedimentation stability and avoiding decomposition for at least 5 days. This time seems reasonable for the preparation, storage, and pumping of the suspensions while their viscosity and stability meet the relevant technological requirements. [ABSTRACT FROM AUTHOR]

Spaceborne spectroscopic imaging offers the potential to improve our understanding of biodiversity and ecosystem services, particularly for challenging and rich environments like mangroves. Understanding the signals present in large volumes of high-dimensional spectroscopic observations of vegetation communities requires the characterization of seasonal phenology and response to environmental conditions. This analysis leverages both spectroscopic and phenological information to characterize vegetation communities in the Sundarban riverine mangrove forest of the Ganges–Brahmaputra delta. Parallel analyses of surface reflectance spectra from NASA's EMIT imaging spectrometer and MODIS vegetation abundance time series (2000–2022) reveal the spectroscopic and phenological diversity of the Sundarban mangrove communities. A comparison of spectral and temporal feature spaces rendered with low-order principal components and 3D embeddings from Uniform Manifold Approximation and Projection (UMAP) reveals similar structures with multiple spectral and temporal endmembers and multiple internal amplitude continua for both EMIT reflectance and MODIS Enhanced Vegetation Index (EVI) phenology. The spectral and temporal feature spaces of the Sundarban represent independent observations sharing a common structure that is driven by the physical processes controlling tree canopy spectral properties and their temporal evolution. Spectral and phenological endmembers reside at the peripheries of the mangrove forest with multiple outward gradients in amplitude of reflectance and phenology within the forest. Longitudinal gradients of both phenology and reflectance amplitude coincide with LiDAR-derived gradients in tree canopy height and sub-canopy ground elevation, suggesting the influence of surface hydrology and sediment deposition. RGB composite maps of both linear (PC) and nonlinear (UMAP) 3D feature spaces reveal a strong contrast between the phenological and spectroscopic diversity of the eastern Sundarban and the less diverse western Sundarban. [ABSTRACT FROM AUTHOR]

This study presents the analysis of the taphonomical processes at the Rosario Mine (Valdeteja Formation, León). The studied beds are an ensemble of normal graded sequences comprised of rudstones and grainstones that pass upwards to packstones and finally to marls. The last sequence culminates in a 3 m thick bed of carbonaceous shales with coal balls. In the limestones there are evidences of breakage, resedimentation and even some reworking. The top of the packstones and the marls show hummocky cross stratification and abundant burrows. The fossils in the limestones represent an allochthonous assemblage, while the marls contain a mostly autochthonous assemblage, typical of a deep marine environment.These sequences were deposited in a deep area of a tropical carbonate platform in a foreland basin, and they resulted from mass flows triggered by large waves followed by quiet background environmental conditions. Tsunamis or cyclones could be the events originating these sequences. The characteristic of the deposit and the palaeogeographical framework have been examined to try to differentiate between these events. The climate and tectonic context during the sedimentation support both possibilities, while the deep environment and the amount of plant remains dragged to the sea seem more consistent with tsunamis. [ABSTRACT FROM AUTHOR]

The study examines the specific features of the structure and composition of strata of the Tyushevskaya basin of Eastern Kamchatka, which formed at the site of the Vetlovsky basin, which is marginal marine in nature. This structure probably began to form in the Late Eocene–Oligocene. A scheme for its evolution is proposed. In the modern structure, sediments of the Tyushevskaya basin overlie the material complexes and structures of various terranes and participate in the accretionary structure of the region. Sedimentary formations are predominantly facies-variable coarse coastal-marine and/or deltaic sediments, which change upsection to deeper-water flysch formations. Oil-bearing manifestations are associated with these complexes. [ABSTRACT FROM AUTHOR]

Channel deposits from meandering rivers have proven to be far more complex than the well‐known lithofacies model consisting of coarse‐grained channel, gravelly channel‐lag and fine‐grained overbank deposits. Sharp bends in rivers are subject to different hydraulic processes than bends with lower curvatures, enabling erosion of inner banks and deposition of fine‐grained sediments in the outer bend, resulting in downstream migration of river bends. This phenomenon is known as counterpoint deposition, forming counterpoint bars. This research investigates whether scroll bars associated with a sharp bend in the Lower Rhine River, The Netherlands, are such a counterpoint‐bar deposit. A counterpoint bar is expected based on: (i) the surface morphology of the scroll bar; (ii) the confinement of the river course by an ice‐pushed ridge resulting in a sharp bend; and (iii) the archaeological context of successive Roman settlements atop the ice‐pushed ridge, potentially moving downstream with the migrating river bend. This hypothesis is tested through detailed borehole descriptions combined with optically stimulated luminescence dating, the latter being a novel approach to identifying counterpoint deposits. The deposits consist of clays and sandy clays with fine sand laminations, and sporadic larger sand bodies. Further upstream these deposits grade into channel deposits dominated by coarser sands with gravels. These lithologies are explained using earlier proposed mechanisms for counterpoint formation; substrata match those described in previously studied counterpoint deposits and their point bar counterparts. Optically stimulated luminescence dates indicate that the Lower Rhine River bend migrated downstream, confirming counterpoint deposition. A migration rate of 1.93 m/year was established through weighted linear regression. This study demonstrates the potential of optically stimulated luminescence dating to investigate counterpoint bar presence. The identified counterpoint bars and associated bend migration provide insight into meandering river dynamics that is crucial for river management and in aiding river restoration and rewilding initiatives. [ABSTRACT FROM AUTHOR]

Both catchment geology and land use surrounding a stream will affect the degree of fine sediment deposition from erosion and its consequent impacts on stream macroinvertebrate communities. While geology and land use have been shown to impact stream communities individually, their interaction has received less attention.We investigated the interaction between geology and land use on stream macroinvertebrate communities in the Tairāwhiti Region, New Zealand. The region has streams that drain harder sandstones and softer shales and mudstones, the latter having some of the highest erosion rates in the world. Macroinvertebrates were sampled each year between 2016 and 2018 at 80 sites in exotic forest, indigenous forest and pasture streams that drained hard or soft geology catchments.Conductivity in pasture and exotic forest streams was nearly twice as high as in indigenous forest streams and higher in soft than hard sediment streams. Deposited sediment cover was greater in soft than hard sediment streams, and greater in pasture and exotic forest streams than in indigenous forest streams. Periphyton cover did not differ between land uses but was higher in soft sediment streams.Ecological health was higher in the indigenous forest sites, intermediate in exotic forest sites and lowest in pasture streams. Biological indices were also higher within each land use in streams draining hard than soft sediment streams. Invertebrate communities appear to be determined primarily by the amount of deposited fine sediment and conductivity, both of which are higher in soft than in hard bottom streams, and in exotic forest and pasture streams.Synthesis and applications: Our results illustrate a complex and strong interaction between geology and land use and the consequent impact on stream macroinvertebrate communities. The combination of soft bottom streams with pasture or exotic forest land use is more detrimental than in similar hard bottom streams. Therefore, regulations for the management of any given land use need to be much stricter in catchments dominated by soft sediment geology. [ABSTRACT FROM AUTHOR]

The concentrations and composition of hydrocarbons (aliphatic, AHCs, and polycyclic aromatic, PAHs) are determined using molecular markers in bottom sediments of the Greenland–Norwegian basin and the Barents Sea (during the 84th cruise of the R/V Akademik Mstislav Keldysh in 2021). The research covered the deep-sea part of the Greenland Basin, the northern part of the East Greenland Ridge, the near-fault zone in the area of the junction of the Mohns and Knipovich ridges, the Western and Northwestern extremities of the Svalbard continental shelf (the Vestnes Ridge, the Ermak Plateau, the Sofia Basin, and the Hinlopen Trough), the Fram Strait, the Orly trough area with the intersection of the Erik-Eriksen trough, and the central part of the Barents Sea. The surface bottom sediments are found to contain a wide range of concentrations of Corg (0.25%–2.71%), AHCs (7–182 μg/g), and PAHs (23–1918 ng/g). The distribution of HCs is determined by the processes occurring in the sedimentary stratum (changes in Eh and fluid flows), and, to a lesser extent, by the lithotype of sediments. Therefore, in the sedimentary stratum, autochthonous components form in the composition of alkanes and naphthalenes form in the composition of PAHs. [ABSTRACT FROM AUTHOR]

• A novel three-equation two-phase flow model is proposed for sedimentation and consolidation. • Fluid pressure increases with initial sediment concentration, necessitating incorporation of non-hydrostatic pressure. • Inertial effects become significant with larger grains, indicating the need to incorporate inertial forces. Sedimentation and consolidation, a multi-physical phenomenon of great significance in aquatic environments, usually involves dynamic pore pressure, inertial effects, fluid-particle interphase interaction and solid stress. However, simplified models for sedimentation and consolidation typically assume hydrostatic mixture pressure and neglect inertial effects without proper justifications. Here, a one-dimensional three-equation two-phase flow model (TTP) is proposed for sedimentation and consolidation, which directly resolves dynamic fluid pressure and inertial terms. The present TTP model is benchmarked against a series of experimental cases and two existing four-equation two-phase flow (FTP) models. It features encouraging performance as compared to measured data and computed results of the existing FTP model. Furthermore, the present TTP model shows superior computing efficiency over the FTP models. To investigate the influences of inertial effects and non-hydrostatic mixture pressure, two simplified versions of the TTP model are constructed and compared with the TTP model. It is shown that incorporating inertial effects and non-hydrostatic fluid pressure are important for accurately predicting the sedimentation-consolidation process. The present study facilitates a promising framework for modelling sedimentation and consolidation, thereby supporting effective sediment management. [ABSTRACT FROM AUTHOR]

Nanofluids have gained considerable attention as potential alternatives to pure fluids in cooling systems, particularly in boiling flow systems operating in two-phase vapor–liquid conditions. While nanofluids enhance heat transfer in cooling systems, a significant challenge associated with their implementation is the issue of nanoparticle deposition and sedimentation. Numerical analyses often neglect the deposition layer formed on the walls of pipes and channels. Disregarding this layer in simulations can lead to significant errors in estimating fluid flow and heat transfer parameters. This study investigates the boiling flow of four different nanofluids (nickel–water, gold–water, aluminum–water, and titanium oxide–water) with a volume fraction of 0.03% and pure water in a vertical tube with a diameter of 1.45 mm using a two-dimensional simulation in MATLAB software. In the simulation, five mass transfer mechanisms including evaporation, condensation, deposition, entrainment, and fluid entry into the sedimentary area are considered. To simulate the sedimentary layer, the rules of the porous media have been used. In addition, Brownian motion of particles and Kapitza resistance are also considered in the calculations. The primary objective is to demonstrate the impact of deposition layer simulation on the heat transfer coefficient (HTC) and critical heat flux (CHF) in various nanofluids. The results indicate that the deposition layer causes an average reduction of 31% in the HTC and 16% in the CHF. The findings emphasize the importance of incorporating deposition layer simulation in analyzing boiling nanofluids. Ignoring sediment phenomenon can result in substantial errors in predicting heat transfer and CHF, with significant implications for the design and optimization of nanofluid-based cooling systems. [ABSTRACT FROM AUTHOR]

Reactive transport modeling (RTM) is an emerging method used to address geological issues in diagenesis research. However, the extrapolation of RTM results to practical reservoir prediction is not sufficiently understood. This paper presents a case study of the Eocene Qaidam Basin that combines RTM results with petrological and mineralogical evidence. The results show that the Eocene Xiaganchaigou Formation is characterized by mixed siliciclastic-carbonate-evaporite sedimentation in a semiclosed saline lacustrine environment. Periodic evaporation and salinization processes during the syngeneticpenecontemporaneous stage gave rise to the replacive genesis of dolomites and the cyclic enrichment of dolomite in the middle-upper parts of the meter-scale depositional sequences. The successive change in mineral paragenesis from terrigenous clastics to carbonates to evaporites was reconstructed using RTM simulations. Parametric uncertainty analyses further suggest that the evaporation intensity (brine salinity) and particle size of sediments (reactive surface area) were important rate-determining factors in the dolomitization, as shown by the relatively higher reaction rates under conditions of higher brine salinity and fine-grained sediments. Combining the simulation results with measured mineralogical and reservoir physical property data indicates that the preservation of original intergranular pores and the generation of porosity via replacive dolomitization were the major formation mechanisms of the distinctive lacustrine dolomite reservoirs (widespread submicron intercrystalline micropores) in the Eocene Qaidam Basin. The results confirm that RTM can be effectively used in geological studies, can provide a better general understanding of the dolomitizing fluid-rock interactions, and can shed light on the spatiotemporal evolution of mineralogy and porosity during dolomitization and the formation of lacustrine dolomite reservoirs. [ABSTRACT FROM AUTHOR]

A comprehensive study of the Maastrichtian–Danian boundary rocks in the Klementyev Mountain section (eastern Crimea) was carried out. The lithological characteristics of carbonate, carbonate–clayey, and clastic rocks are scrutinized. The dynamic of changes in the benthic and planktonic foraminiferal assemblages is analyzed. The geochemical and isotopic data were obtained for this section for the first time. The stratigraphic range of the upper Maastrichtian and lower Danian has been specified. The late Campanian–early Maastrichtian age of the underlying rocks has been confirmed for the first time. Sediments of the Klementyev Formation were deposited in a deep-sea pelagic paleoenvironment on the submerged part of the outer shelf, whereas the overlying Lower Danian sediments were deposited in shallow waters of the inner shelf with terrigenous sedimentation and high hydrodynamic activity. [ABSTRACT FROM AUTHOR]

The paper considers the composition of sandy rocks from the Upper Triassic deposits of the Mongugai Formation of southwestern Primorye and presents the results of its paleogeodynamic interpretation. It has been established that, according to their mineralogical and geochemical parameters, sandstones are petrogenic, correspond to graywackes and, only partially, to lithite arenites, are characterized by a significant degree of geochemical maturity of the clastic material, and their formation occurred due to the erosion of significantly weathered parent rocks of the source areas. Generalization and paleogeodynamic interpretation of the data obtained indicate that sedimentation in the southwestern Primorye in the Late Triassic occurred in basins related to the active continental margin settings probably complicated by strike-slip dislocations along transform faults. The dominant source of detrital material was continental land: cratons and crystalline basement inliers surrounding the rift zones or along transform faults. Felsic granite-metamorphic complexes were eroded with the participation of sedimentary rocks enriched with ancient components. A secondary source was a deeply dissected continental-margin igneous arc, which supplied an additional amount of sialic material, as well as a small amount of the basic–intermediate volcaniclastic rocks into the basin. The U–Pb geochronological studies of detrital zircons from sandy rocks of the formation made it possible to establish the age and the possible position of igneous complexes, destruction of which formed the sediments. [ABSTRACT FROM AUTHOR]

The main purpose of this article is to model an industrial spiral-type gravitational coalescer by applying population balance as the governing equation. In this model, considering the two-dimensional movement of crude oil flow in the coalescer, the mechanisms of differential sedimentation, laminar shear, and Brownian motion are considered to determine the collision rate of droplets. Then, the population balance equation was solved to determine the droplet size distribution, dehydration, and desalination efficiency using the class method. The simulation results were in good match with the gathered industrial data. Finally, the influence of interfacial tension of water and oil, the pressure drop of the mixing valve, oil temperature, oil density, and washing water flow rate on the process efficiency was analyzed. The modeling results indicated that increasing the interfacial tension of water and oil from 30 to 36 mN/m and the oil density from 800 to 900 kg/m3 will decrease the water removal efficiency by 4.35% and 14.18%, respectively. Also, increasing the temperature of oil from 300 to 340 K and the volume fraction of washing water from 3% to 15% improves the efficiency of separating water from crude oil by 9.55% and 9.95%, respectively. [ABSTRACT FROM AUTHOR]

Since the building roof acts as hub for atmospheric sediment deposition, the attached microbes can enter rainwater storage tank with ease to cause health issue for rainwater users. This study aims to explore the trend of roof-top deposited microbes in the different areas of Ikorodu local Government Area at Lagos, Nigeria. This paper also tests the hypothesis that the roof sediment deposition being a significant source to home bacteria. The total deposition rate on the roof for 34 weeks, which include 17 rainy and 17 dry weeks, were investigated. The enumerated bacteria was obtained from the roof deposit samples, where four representative different sites have been analysed to study the solid depositions and microbes within the area thoroughly. The sites were selected judging by their levels of sanitation and vegetation rate. The experimental investigations showed that enumerated microbes and total suspended solid (TSS) depositions in the different areas were higher in the dry season compared to rainy season, and the highest deposition was experienced in the Harmattan period. In addition, the results showed that areas with poor drainage infrastructure and poor sanitation have the roof-top deposition with higher bacterial count than good sanitation areas; while the unpaved and unvegetated areas produced higher deposits than the paved and vegetated areas. In terms of contamination sources, this study has illustrated that the particulate deposition on the roof-top prior to collection has further contaminated the roof-harvested rainwater. [ABSTRACT FROM AUTHOR]

Cobalt-rich ferromanganese crusts (CRC) are potential resources for Co, Ni, Pt, and other strategic metals. The CRC thickness varies from a few mm to more than 100 mm at various distance scales over the rock outcrops in the seamounts. However, their variation patterns and controlling factors are not well understood. We conducted a comprehensive small-scale survey, including shipboard acoustic measurements, seafloor observations, and rock drilling over the Xufu Guyot of the Marcus-Wake seamounts in the Northwestern Pacific to characterize the thickness variations on a scale of several kilometers with the topography and geological evolution of the guyot. Rock drilling revealed that thicker CRC (>100 mm) tend to occur on the margins and flat areas on the guyot, while thinner CRC are associated with carbonate reef mounds over the volcanic pinnacles and seamount slopes. The microstratigraphic description indicated that the CRC thickness is strongly related to the geological evolution of the guyot, mainly the stability of the substrate rocks and coverage with calcareous pelagic sedimentation. [ABSTRACT FROM AUTHOR]

The suspension of porous particles in fluids occurs widely in various natural and industrial processes. However, the sedimentation behavior of porous particles is not extensively understood as the solid impermeable counterparts. In this work, the drafting–kissing–tumbling (DKT) phenomenon in a narrow channel containing porous particles is investigated by the multi-relaxation-time (MRT) lattice Boltzmann method (LBM). The initial particle spacing L p * (1.5 ∼ 6) and Darcy number Da (8 × 10 − 6 ∼ 6 × 10 − 2 ) are examined on the sedimentation process of two particles under three initial arrangements, i.e., the trailing particle is porous (case 1), the leading particle is porous (case 2), and both the particles are porous (case 3). The results show that the presence of porous particles can enhance the interactions between two particles, and increasing the penetrability reduces the particle drag force to accelerate sedimentation. The drafting time is insensitive to Da at small L p * , and it decreases with Da at large L p * in cases 1 and 3 while it changes to increase with Da in case 2. A phase diagram with respect to Da and L p * is further extracted to identify three sedimentation modes of particle pairs. It is found that the transition between the one-off DKT and repeated DKT modes is not affected by L p * in cases 2 and 3, while the critical condition for the non-DKT and one-off DKT modes depends strongly on Da and L p * in case 2. [ABSTRACT FROM AUTHOR]

Mineralogical and geochemical studies have been undertaken on the Triassic to Lower Jurassic Adigrat Sandstone of the Blue Nile Basin of central Ethiopia to infer its source rock type, paleoweathering, and paleoclimatic history. The Adigrat Sandstone occurs at the basal section of the Mesozoic sedimentary formation and unconformably overlays the Neoproterozoic–Paleozoic crystalline rocks, or locally, the Karroo sediments in the northern Blue Nile Basin. A mineralogical study reveals that quartz (Q), feldspars (F), and lithic fragments (L) are the framework grains of the sandstone. On the QFL diagram, the plot of the modal composition of the sandstone mainly falls within the feldspathic arenite and quartzose arenite fields. The geochemical data of the lower section of the sandstone mainly falls within the arkose and subarkose fields, whereas the upper section data falls within the quartzose and sublithic arenite fields. Mineralogical and geochemical weathering indices indicate that the provenances of the Adigrat Sandstone were exposed to pronounced weathering intensity, where the lower part of the sandstone was controlled by arid to semi‐arid conditions, whereas the upper section was linked to humid to semi‐humid (tropical to subtropical) climatic conditions. Mineralogical and geochemical data also indicate that mafic to intermediate basement rocks were the primary source rocks of the sediment. Perhaps the sediment was assumed to have been reworked by multi‐cyclic sedimentary processes. The discriminant function diagram, the REE pattern, La/Th vs. La/Yb, and the Th–Hf–Co plot are consistent. A comparison of provenance studies for the Adigrat Sandstone in the Blue Nile Basin and the Mekele outlier of northern Ethiopia indicates that the sediment of the former is highly sorted, experienced higher weathering intensity, and compositionally derived from mafic to intermediate crystalline rocks. On the other hand, the sediment of the latter is essentially a weathering product of felsic rocks. [ABSTRACT FROM AUTHOR]

The impacts of the growth and linkage of fault segments on sedimentation in a lacustrine rift basin, the Weixinan Depression, the Beibuwan Basin, in the northern South China Sea, which has been demonstrated to have huge petroleum potential, are elucidated on the basis of well-constrained 3D seismic data. Two main fault systems, the No. 1 boundary fault system and the No. 2 fault system, were developed in the Weixinan Depression. The evolution of the lower basement is based on the No. 1 fault system, which controls the distribution of depocenters (ranging from 450–800 m) within the lower structural layer. It includes the five fault segments isolated at the initial stage, the interaction and propagation stage, the linkage stage, and the decline stage. The No. 2 fault system governs the deposition of the upper structural layer with a series of discrete depocenters in the hangingwall. Initially, it comprises several right-order echelon branching faults. Each branch fault rapidly reached the existing length and maintained a constant length while establishing soft links with each other in the subsequent displacement accrual. The development of topographic slopes, transition zones, transverse anticlines, and related fault troughs and gullies related to the activity of the No. 1 boundary fault system is the main controlling factor that induces the differential development of the western, middle, and eastern sections of steep slope fans. The differential subsidence effect along the No. 2 fault system is responsible for the multiple 'rising-stable' stage changes in the relative lake level during the development of axial delta deposits. This study will help elucidate the different controls of extensional fault systems on associated sedimentation, as well as rift basin development in the South China Sea and similar areas throughout the world. [ABSTRACT FROM AUTHOR]

Vegetation plays a key role in trapping sediments and further controlling pollutants. However, few studies were conducted to clarify the erosion and deposition laws of sediments and the influence factors caused by vegetation patch properties, which is not conducive to the revelation of riverbank protection and erosion prevention. Therefore, this study investigated the change in scouring and deposition characteristics around submerged vegetation patches of nine kinds of typical configurations and their influencing factors. Vegetation patches were assembled from three vegetation densities (G/d = 0.83, 1.3, and 1.77, representing dense, medium, and sparse, respectively), and three vegetation patch thicknesses (dn = 170, 400, and 630, representing narrow, usual, and wide, respectively), to measure vegetation patch property influences. Flow velocity, scouring, and deposition characteristics under nine patches were determined by a hydraulic flume experiment, three-dimensional acoustic Doppler velocimetry (ADV), and three-dimensional laser scanner, and then ten geometry and morphology indices were measured and calculated based on the results of laser scanning. Results showed that both vegetation patch density and thickness were positively related to the turbulence kinetic energy (TKE) above the vegetation canopy, and only vegetation patch density was negatively related to the flow velocity above the vegetation canopy. The relation between the product of density and vegetation patch thickness and erosion area in planform (EA) showed a power function (R2 = 0.644). Both density and vegetation patch thickness determined the scouring degree, but deposition location and amount did not rely on each one simply. On average, medium density showed the smallest maximum erosion length (MEL), EA, deposition area in planform (DA), and average deposition length (ADL) and a minimum of the above parameters also occurred at narrow vegetation patch thickness. The shape factor of the erosion volume (SFEV), the shape factor of the deposition volume (SFDV), ADL, and MEL of medium density and narrow thickness vegetation patch (G/d = 1.3, dn = 170) were significantly smaller than that of other types of patches. DA and equivalent prismatic erosion depth on the erosion area (EPED) were significantly linearly related (R2 = 0.766). Consequently, most sediment was deposited close to the vegetation patch edge. It is suggested that vegetation patch thickness and density should be given to control sediment transport. In particular, natural vegetation growth changes vegetation patch density and then alters vegetation patch thickness. Management and repair need to be first considered. The results of this study shed light on riparian zone recovery and vegetation filter strip mechanism. [ABSTRACT FROM AUTHOR]

Dams are one of the most critical hydraulic structures worldwide. Sediment, entering the reservoirs of the dams with the water flow due to human interference in the dam catchment area, gradually destroys the functional storage through a deposition. Sedimentation threatens the sustainability of all reservoirs in the absence of adequate prevention and mitigation measures. Deposition of sediments in reservoirs can also affect the safe and proper operation of water intakes and bottom outlets belonging to the vital outlet structures. Turbidity currents are among the main impacts on dam reservoir sedimentation. One technique to decrease the impact of more sedimentation is to use bottom outlet gates that preserve the reservoir's useable volume. This procedure may affect the quality of water exiting the dam. The present study experimentally investigated the venting of turbidity current of lock exchange with varying concentrations on the rigid bed, while there were two outlet gates with various levels and diameters at the same time. According to the available information, in the case of , the average value of the concentrated input current was equal to the output concentration, which is the best level for the outlet gate installation based on the primary experimental conditios. The discharge efficiency is also higher when the inlet concentration is lower. [ABSTRACT FROM AUTHOR]

Engineering construction disturbs the Earth's surface and exacerbates soil erosion, resulting in sediment contributions at the watershed scale, the spatiotemporal variation of which remains to be clarified. Based on a typically disturbed catchment, soil samples were collected from sources such as forests, grasslands, spoil heaps, and exposed slopes. Sediment deposition was sampled in 2022 and 2023 along the main channel and fingerprinting technology was employed to calculate the relative contributions of different sources. The results indicated that the optimal composite fingerprints comprising Na₂O, Li, Sr, and Ce could effectively resolve the contributions of different sources. Natural sources were the main sediment contributors, but the average contribution decreased from 72.96% to 58.73% over two periods. In contrast, the contribution of spoil heaps and exposed slopes increased from 27.04% to 41.27% and the area percentage increased from 0.18% to 0.30%. The spoil heap represents the relatively large area of disturbance and its contact length with the river determines the sediment contribution rates, which varied spatially in a quadratic trend along the channel. Meanwhile, the sediment contribution of relatively small and dispersed exposed slopes could be quantified using a linear equation of the disturbance weighting indicator (DWI) composed of disturbed area and flow distance. These results would be helpful in assessing the environmental impact of engineering disturbances and optimizing mitigation measures. [ABSTRACT FROM AUTHOR]

This study presents the historical sequence of the inter-relationship between climate, sea-level change, hydromorphology, and the society in the "Delta of Neretva", Croatia. This study aims to support future-oriented planning, since the cumulative impact of climate and mean sea-level changes on the delta hydromorphology and socio-economy is very uncertain and difficult to predict. In particular, the sustainability development of the Delta of Neretva requires a long-range strategy that is complicated to outline. In the proposed approach, hydromorphology is used as a sustainability indicator since it considers both the physical character and water content of the delta and looks at how nature and human activities influence the biophysical system and economy. The direction of delta progression and persistence of socio-hydromorphology are evaluated with the assessment of system entropy generation considering the simple system state function. Such a method overcomes the difficulties posed by top–down and bottom–up approaches, making future scenarios and cumulative impacts visible and understandable to stakeholders. The historical co-evolution results indicate that the delta in the future could become a submerged estuary (rias), that is, a sea bay as a result of the subsequent delta progradation caused by an MSL rise, similar to the progradation during the Holocene, and decreasing sediment deposition due to anthropologic processes in their watershed. Technology (policy) assessment suggests that adaptation measures that gradually support environmental security and sustainable livelihoods, i.e., increase natural order at a society-acceptable cost, are preferable. [ABSTRACT FROM AUTHOR]

The Pazanan anticline is one of the most important condensate gas reservoirs in Iran, which is located in the southeastern part of the Dezful Embayment with a northwest-southeast trend. The structural analysis and deformation of this anticline based on the interpretation of existing subsurface data (including 3D-seismic data and drilled wells data) indicates that the folding style of this anticline in the Asmari reservoir and older formations is faulted asymmetric detachment folding. Based on the structural interpretation of the tops of the Asmari, Sarvak, Fahliyan, Gotnia formations and a deeper horizon (probably top of the Kangan) in the transversal seismic sections of the Pazanan anticline, it could be divided into 3 main culminations known as southeastern, central and northwestern, which are separated from each other by saddles. The interpretation of the observed seismic data and stratigraphic column clearly shows that the sedimentation thickness of formations, especially the Late Cretaceous and Paleocene, have been reduced due to the uplift of the Hendijan-Izeh Paleo-high, so that the Ilam and Gurpi formations have not been deposited or eroded in the Paleo-high area. The interpretation of the Asmari reflector in the seismic time slices, with assuming that the changes in the spatial dimension (along the axis of the Pazanan anticline) are equivalent to the changes in the time dimension (during the folding time of the anticline); shows folds growth in the central and southeastern culminations of the Pazanan anticline were simultaneously but separately, while the northwestern culmination of this anticline started to folding after increasing the deformation and finally connected to the central culmination. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Recent analytic-philosophical works in the field of situated cognition have proposed to conceptualize the self as deeply entwined with the environment, and even as constituted by it. A common move has been to characterize the self in narrative terms, and then to argue that the narrative self is partly constituted by narratives about the past that are scaffolded (shaped and maintained) by, or distributed over, a variety of objects that can rekindle episodic memories. While we are sympathetic to these approaches, here we propose a different strategy to situate the self—one which can be seen as complementing the narrative one, and which draws from concepts and ideas central to the phenomenological-existentialist tradition. We suggest, first, that the self has a sense of its past not just via narratives and episodic memories, but in virtue of being embodied and thus, importantly, sedimented (in other words, it has, or rather is, a body memory). Embodiment and sedimentation, in turn, always necessarily imply an environment or a situation, entailing that the self is also inherently situated. Second, we discuss the future-oriented dimension of selfhood, and argue that we understand ourselves as projected into the future, again not necessarily only narratively and reflectively, but also tacitly, in a bodily and inherently situated way. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Water Treatment is the property of CNOOC Tianjin Chemical Research & Design Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aiming at the problems such as low settling speed and poor solid-liquid separation effect of a uranium ore high-calcium slurry, static flocculation method was used to settle high-calcium pulp of a uranium ore, and the effects of flocculant type, dosage, mixed flocculant ratio and adding method on the settling effect were investigated. The results show that the settling rate of high calcium pulp can be significantly increased by the mixed flocculant prepared by WZ944 flocculant and 5330 flocculant. The optimal mass ratio of the two flocculants is 1:1, and the minimum dosage of the mixed flocculant is 35 g/t. The research results can provide reference for the optimization design of the uranium ore solid-liquid separation process. [ABSTRACT FROM AUTHOR]

Lake sediments are ideal archives to evaluate the interactions between climatically driven environmental responses and human activity on seasonal to multi‐decadal timescales. This study focuses on the unique sediments of Diss Mere, the only lake in England providing an annually laminated (varved) record for most of the Holocene. We combine microfacies analysis with X‐ray core scanning data to explore the influence of natural and human‐led changes on sediment deposition over the past 10 200 years and evaluate the sensitivity of the lake sediments to climate variability through time. Variability of titanium (Ti), calcium (Ca) and silica (Si) explain most of the lithological changes observed in the sediment and we identify three stages with low (10 290–2070 cal a bp), intermediate (2070–1040 cal a bp) and intensified (1040 cal a bp – present) human influence. During the first stage, where varved sediments are preserved, Ti is low due to the minimal detrital input into the lake. Ca and Si during this stage reveal high‐amplitude variability responding to seasonal changes in sediment deposition. The termination of varved sediment preservation and increases in sedimentation rates coincide with a major rise in Ti after this first stage, marking the intensification of human activity around the lake. Ca is used here as an indicator of temperature‐included calcite precipitation, and the long‐term variability of the Ca profile resembles Holocene temperature evolution. This continues during periods of intensified human activity, suggesting that the Diss Mere sediments remain sensitive to climate through time. [ABSTRACT FROM AUTHOR]

Wetlands formed by natural sediment deposition account for a large proportion of new coastal lands, and these new wetlands usually have active ecosystems and obvious ecological effects. However, previous studies largely overlooked this sediment‐caused wetland expansion, and the spatiotemporal variation in these wetlands and future response to sea‐level rise (SLR) have not been determined. Here, we employed satellite observations to quantify the seaward expansion of coastal lands in China over the past two decades. A total land expansion of 6,651 km2 was found, and wetlands and artificial surfaces dominated, accounting for 32% and 25%, respectively. Subsequently, we utilized an integrated model to estimate the response of these new wetlands to SLR in the 21st century, that is, we estimated the wetland gain from sediment deposition and loss due to SLR. The results indicate that under the current condition of sediment availability, the area of China's new coastal wetlands is projected to increase by 200%–261% compared to that in 2020 based on four SLR scenarios, despite the unavoidable impact of SLR. These increases are accompanied by the continuous enhancement of carbon accumulation. Wetland changes are influenced by factors such as sediment deposition, SLR and storm surges, as well as the continued effect of local natural and anthropogenic factors. These results show the importance of understanding the ecological effects of new wetlands and constructing specific protection measures for sustainable development. Plain Language Summary: Compared to anthropogenic reclamation, sediment deposition represents an alternative mechanism for the formation of coastal lands. These newly formed lands possess highly dynamic ecosystems and offer additional land resources, making them immensely important for ecological environments and societal development. This study focused on the spatiotemporal changes in newly formed lands in China's coastal regions over the past two decades, and an examination of the land use status was conducted. The results show that wetlands constitute the predominant component of these new lands, rather than artificial surfaces. Using an integrated model, we estimated the future response of these new wetlands to sea‐level rise and the corresponding carbon accumulation trend. Additionally, the factors influencing the area of new wetlands was analyzed to provide valuable insights and recommendations for future wetland conservation policies. Key Points: A total of 6,651 km2 of newly formed coastal lands were found in China in the past 20 years, and wetlands were the predominant componentCarbon accumulation in China's new coastal wetlands is projected to increase by 200%–261% by 2100 under various sea‐level scenariosOur results show that wetland change is primarily driven by sediment availability and that wetland loss is maintained with sea‐level rise [ABSTRACT FROM AUTHOR]

Raw water must be purified before being distributed to any village, town, or city. To purify raw water, various significant processes must be performed in a water treatment plant, with sedimentation being one of the most important. Solid particles in the form of dirt and other contaminants can be found in raw water, especially during the rainy season, which can be removed through sedimentation. Plate settlers or tube settlers are commonly utilized in sedimentation units to treat water quickly, reducing the detention time to 15-20 minutes. This study modified conventional tubes in terms of manufacturing and repositioning to increase turbidity removal in raw water. The experimental work was carried out for one year to calculate the balanced turbidity of the raw water using conventional and modified square-shaped tube settlers. Mathematical analysis was deployed to compare the output from one year's data from both experimental studies. Regression, R², relative standard deviation, and ANOVA were employed to analyze the experimental models, and the observed and calculated findings were compared. The results show that the modified tube settlers removed more turbidity from the raw water than the conventional ones. [ABSTRACT FROM AUTHOR]

This paper investigates the deep-sea morphology and sedimentary processes within the Santa Catarina Plateau and the Vema Channel, prominent features crucial for influencing bottom circulation in the western South Atlantic and regulating the exchange of deep and bottom waters between the Argentine and Brazil basins. The study leverages a unique dataset comprising multibeam data for generating detailed digital terrain models and sub-bottom profiling records, alongside numerical modeling of bottom current velocities (GLORYS12V1 reanalysis). Numerous sediment waves, predominantly cresting mudwaves and mass-wasting deposits associated with steeper sea floor gradients, were identified in the region, aligning with findings from the Argentinian and South Brazilian slopes. The investigation of these features contributes not only to the identification of contourites but also to the enhancement of understanding regarding deep-water circulation within the 3,500-to-4,500-meter range. This depth range serves as a critical transition zone between the Argentine and Brazil basins and plays a pivotal role in elucidating the northward distribution of Antarctic Bottom Water (AABW), an integral component of the Atlantic meridional circulation. In contrast to prior studies that focused on specific regions of the plateau, this research offers a comprehensive overview of the region's morphology and sedimentary processes, thereby advancing comprehension of deep-water circulation dynamics between the Argentinian and Brazilian basins. [ABSTRACT FROM AUTHOR]

A sudden angle change between the Y-shaped diversion channel and the inlet tank of the circular pump station often leads to boundary layer separation and large vortex formation. These flow patterns can cause significant sediment deposition in sediment-laden rivers, reducing pump efficiency. A mixture model is introduced to describe water-sediment two-phase flows. Simulation results analyze vortex characteristics and formation mechanisms, and evaluate potential sediment deposition areas. Without rectification, vortex areas cause significant sediment migration towards the sidewalls of the Y-shaped diversion channel and pump inlet. Diversion measures like sills and pressure plates are introduced to reduce flow vortices. Results show that sills generally optimize flow structures. Sills in the main Y-shaped diversion channel outperform those in other channels in terms of optimization. Pressure plates also optimize flow structures. Vortex structure and position are closely related to the distance between the pressure plate and the circular intake tank. Optimized measures with pressure plates significantly reduce the flow deviation angle and improve flow velocity uniformity. Numerical simulation accuracy is validated through experiments. Results reveal the formation mechanism of adverse vortices and their sedimentation effects, which are detrimental to pump stations. The proposed rectification scheme provides theoretical support for optimizing pump station operation. [ABSTRACT FROM AUTHOR]

A filter unit (FU) is a structure installed with the aim of protecting the foundation of an embankment revetment from riverbed scouring, and there are cases in which sediment is deposited in the surrounding area after installation. Vegetation growth in sediment can improve the environment and protect revetments. Hydraulic experiments and numerical calculations were conducted to investigate how suspended sediments are deposited around FUs over a large area within a short period of time. We performed suspended sediment deposition experiments using FU models and confirmed that sediment deposition can be calculated accurately using a two-dimensional planar model. We also analyzed FU placement and its impact on topographical changes in an actual river in which FUs were installed. The results showed that (1) the continuous placement of FUs inhibits sediment deposition on the downstream side; (2) arranging FUs at intervals facilitates sediment deposition even under small-scale floods; and (3) employing an interval of half the FU width for every three or more FUs can effectively promote suspended sediment deposition at intervals. [ABSTRACT FROM AUTHOR]

Estuarine systems that provide valuable ecosystem services to society and important foraging and rearing habitat for fish and wildlife species continue to undergo degradation. In Puget Sound, WA, as much as 70–80% of historic estuarine habitat has been lost to anthropogenic development, and continued losses are expected through the end of the twenty-first century due to rising sea levels. To evaluate whether Puget Sound's estuarine habitats will keep pace with current and projected sea-level rise (SLR), we assessed vertical rates of elevation change from a regional network of surface elevation tables and marker horizons (SET-MH). Over the past two decades, SET-MH equipment has been installed throughout a variety of habitats in five Puget Sound estuaries: the Nisqually, Snohomish, Stillaguamish, and Skagit River estuaries, and Padilla Bay. These data provide a unique opportunity to assess elevation change and habitat resilience across a spatiotemporal and environmental gradient. We observed different rates of surface elevation change among estuaries and habitats (Nisqually = 4.64 ± 2.81 mm/year, Snohomish = 5.71 ± 5.83 mm/year, Stillaguamish = 12.82 ± 10.29 mm/year, Skagit = 16.13 ± 7.57 mm/year, Padilla = − 1.25 ± 1.58 mm/year). The highest rates were found at restoring sites with regular sediment input in the Stillaguamish and Skagit estuaries, whereas rates were consistently negative at low elevation sites in sediment starved Padilla Bay. Many sites in Puget Sound appear to be keeping pace with current rates of relative SLR, and some areas are on track to exceed projected rates through the end of the century. These findings indicate that Puget Sound's estuarine habitats can be resilient to rising tidal levels—as long as sediment delivery is maintained. [ABSTRACT FROM AUTHOR]