Estuary Area Research Articles

Analyses of sea surface chlorophyll a trends and variability from 1998 to 2020 in the German Bight (North Sea)

Abstract. Satellite remote sensing of ocean colour properties allows observation of the ocean with high temporal and spatial coverage, facilitating the better assessment of changes in marine primary production. Ocean productivity is often assessed using satellite-derived chlorophyll a concentrations, a commonly used proxy for phytoplankton concentration. We used the Copernicus GlobColour remote sensing chlorophyll a surface concentration to investigate seasonal and non-seasonal variability, temporal trends, and changes in spring bloom chlorophyll a magnitude. Complementary, we analysed the chlorophyll a relationship with sea surface temperature and mixed-layer depth in the German Bight from 1998 to 2020. Empirical orthogonal functions were employed in order to investigate dominant spatial and temporal patterns (modes) related to the main processes of chlorophyll a variability. Multi covariance analysis was used to extract the dominant structures that maximize the covariance between chlorophyll a and sea surface temperature mixed-layer depth fields. High levels of chlorophyll a were found near the coast, showing a decreasing gradient towards offshore waters. A significant chlorophyll a positive trend was observed close to the Elbe estuary and adjacent area, while 55 % of the German Bight was characterized by a significant chlorophyll a negative trend. The chlorophyll a non-seasonal variability showed that the first four modes explained around 45 %, with the first and second modes related to inter- and intra-annual variability, respectively, observed in the temporal principal components spectral analyses. Monthly chlorophyll a concentration anomalies co-varied by 45 % with sea surface temperature anomalies and 23 % with mixed-layer depth anomalies. The monthly averages of chlorophyll a anomaly fields were suitable to investigate long-term trends and variability. The rising water temperature, combined with its indirect effects on other variables, can partially explain the observed trends in chlorophyll a.

Retrieval of total suspended matter concentration in the yellow river estuary offshore area based on QAA-RF model

ABSTRACT Total suspended matter is one of the crucial water quality parameters for both inland and marine environments, and a key role in evaluating the water quality of estuaries and offshore areas. Each year, the Yellow River carries a significant amount of sediment into the semi-enclosed Bohai Sea, results in a prolonged high concentration of total suspended matter in the offshore areas of the Yellow River Estuary. This study focuses on the offshore region of the Yellow River Estuary in China. Utilizing Sentinel-2 satellite imagery data from 2020 to 2023 and in-situ measured data from August 2020 to August 2022, to address the lack of physical mechanisms currently studied in machine learning retrieval methods, a model that integrates the physics-driven Quasi-Analytical Algorithm (QAA) and data-driven Random Forest (RF) is employed for the retrieval of total suspended matter concentration in the study area. The fused model (QAA-RF) is compared and analysed against regression models and standalone machine learning models. The results indicate that the accuracy of machine learning retrieval models is consistently higher than that regression models. The QAA-RF model demonstrates the highest accuracy (R 2 = 0.87, MAE = 5.01 mg L−1, RMSE = 6.39 mg L−1). Based on the QAA-RF model and the imagery data, monthly total suspended matter concentration is conducted in the study area. The retrieval results indicates that: (1) the total suspended matter concentrations is primarily concentrated in the near estuary region, with concentrations decreasing as distance from the estuary increases. (2) the total suspended matter concentration exhibits a distribution pattern with higher values in spring and winter, and lower values in summer and autumn. (3) the concentration of total suspended matter shows relatively small fluctuations at the annual scale from 2020 to 2023.

Observation of radial velocity along the Yangtze River based on sentinel-1A

ABSTRACT Estuaries and coasts runoff plays a crucial role in the dynamics of the ocean system. However, the current emphasis on synthetic aperture radar (SAR) retrieved current velocities has been on studying strong boundary currents and large-scale ocean circulation, resulting in relatively limited observational research on estuarine current velocities. This study aims to observe the current velocities in the Yangtze River estuary area using Sentinel-1A SAR data. The findings indicate a high agreement between the current velocities retrieved by Sentinel-1A and those observed at hydrographic stations, showcasing the characteristics of current velocity distribution associated with seafloor topography. This highlights the significant potential of SAR in observing estuarine current velocities, contributing to the analysis of benthic topography and the statistics of river runoff.

Assessment of suitability of the Dniester River's water for drinking water supply

The Dniester is a transboundary river between Ukraine and the Republic of Moldova. It is the second longest river in Ukraine and the ninth in Europe. From its source to a town of Staryi Sambir, the Dniester flows through the Carpathian Mountains, then across the flat territory of Ukraine and Moldova. The Dniester Basin extends across seven regions in southwestern Ukraine (Lviv, Ivano-Frankivsk, Ternopil, Khmelnytskyi, Vinnytsia, Chernivtsi and Odesa Regions). A small area of the river in its upper reaches is located in Poland. The basin's shape is a very elongated oval that is curved in the middle, about 700 km long with an average width of 120 km. As it flows into the Black Sea, the Dniester River forms the Dniester estuary in Odesa region (between Ovidiopol and Bilhorod-Dnistrovskyi districts). The estuary area of the Dniester River is a complex landscape system at the sea-river-land contact. Drinking water is an important factor determining a person's health. Due to the intensive development of industry, agriculture and utility services, the number of pollutants that enter the environment and worsen the quality of drinking water in Ukraine keeps increasing. This increases the risk of toxic and infectious diseases spread among the population that consumes such low-quality water. That is why solving the problem of drinking water monitoring and assessment of its quality is a pressing task requiring urgent action. The article examines the quality of water for drinking needs at the water intake site of the Dniester River, a town of Biliaivka, for 2018-2022. Water quality assessment was carried out according to DSTU 4808: 2007 based on average and worst values. The methodology covers 80 indicators and, in accordance with sanitary legislation, is divided into seven separate groups (blocks). According to hygienic standards, the quality of river water is considered suitable for use if it belongs to quality classes 1-3. In this research, the analysis was carried out according to 23 indicators included in three groups, so the assessment is considered as tentative: Group I - organoleptic indicators (chromaticity, turbidity); Group II - general sanitary indicators (dry residue (mineralization), sulfates, chlorides, magnesium, alkalinity, hydrogen index, ammonium nitrogen, nitrite nitrogen, nitrate nitrogen, phosphate phosphorus, dissolved oxygen, bichromate oxidation (COD), BSK5); Group VII – toxicological parameters (total iron, manganese, chromium (VI), zinc, petroleum products, synthetic surface active agents (surfactants), volatile phenols). It was determined that, according to the average values, the water quality of the Dniester at the water intake site is characterized as "good", which means it has clean water of acceptable quality. As for the worst indicators, the water was assessed as transitional in quality from "good" (clean) to "satisfactory" (slightly polluted).

Contamination, fraction, and source apportionment of heavy metals in sediment of an industrialized urban river in China

In this study, we conducted an analysis of the heavy metal concentrations, health risk assessment, fraction and source interpretation in surface and core sediments from main stream of the Pearl River and Pearl River Estuary (RRE) area. Results showed that the higher deposited heavy metal concentrations in sediments occur at the Pearl River. The concentrations of heavy metals in surface sediments from the studied locations are in a descending order: Zn > Cr > Cu > Ni > Pb > Cd. Regarding chemical fractions, Cd showed the highest proportion of acid soluble fraction (F1) among all studied heavy metals. The high mobility of Cd poses a significant threat to water bodies and the surrounding environment. The potential ecological risk index (RI) showed the Pearl River sediments exhibited significantly higher values than the estuary sediments. Cd was found to be the primary contributor to potential ecological risk, accounting for 74% of RI. The health risk assessment showed the total hazard index (HI) for child was exceeded 1 mainly driven by Zn, indicating that the child population was at risk of non-carcinogenic effects. Besides, unacceptable carcinogenic risk in both Pearl River and estuary area were observed for children. The positive matrix factorization (PMF) model was used to ascertain sources of six heavy metals and apportion their contributions in sediments. The results showed that the source contributions of natural, industrial, and mixed sources from coal combustion and traffic emissions accounted for 39.81%, 34.10%, 26.10%.

Evaluation of water quality fluctuation in the tidal reach under the impact of on shore wastewater discharges based on MIKE 21 model in dongguan, China

The text discusses the study of water quality simulation in the lower reaches of the Dongjiang River basin—tidal river section. Utilizing MIKE 21 software, an integrated 2D hydrodynamic-water quality coupled mathematical model was constructed for the lower reaches and estuary area of the Dongjiang River. The model simulated the hydrodynamic characteristics near the wastewater outlet and the impact of pollutant discharge on the water quality in the study area. The simulation results indicate: (1) During wet and dry seasons, the overall flow pattern remains consistent, with the ebb current velocity slightly greater than the flood tide current velocity beside the outlet. The flow velocity is generally greater during wet season compared to dry season. Interestingly, the flow direction during flood and ebb tides is completely opposite and tides have a great impact on the maximum flow velocity in Xialu Connecting channel. (2) Under normal discharge conditions, the increment of COD, NH3-N, and TP in most areas of Zhongtang Waterway, Daoyun Waterway, and Hengchong Waterway is less than 5 mg/L, 0.1 mg/L, and 0.02 mg/L, respectively, indicating a minor impact on water quality; While in the event of an accidental discharge, the concentration increment is in the range of 5–30 mg/L, 0.1–0.25 mg/L, and 0.02–0.05 mg/L, respectively. COD causes the most significant water quality changes and will severely impact the water environment of the Dongjiang River basin. Furthermore, pollutant dispersion is more extensive during dry seasons due to reduced river flow and weaker dilution capacity. (3) Overall, the results underscore the critical importance of accounting for both tidal and seasonal dynamics in simulation of estuarine water quality.

Development of a detailed bathymetry map of the Nhat Le estuary, Quang Binh province by remote sensing image treatment

Multispectral remote sensing images with the advantages of low cost, wide area coverage, and increased resolution have been widely used recently for determining the bathymetry of coastal waters. In this study, the correlation equation is developed based on the Landsat 8 OLI satellite images captured on September 22, 2022, and the survey data measured during the time period of September 12–22, 2022, was used for mapping bathymetry in the Nhat Le Estuary area, Quang Binh Province, a relatively clear area from sediment. The correlation between the image and the field survey data is quite good, with R2 = 0.88. This shows that Landsat 8 OLI data is suitable for mapping sea areas with depths up to 20 m.

Study of physiochemical parameters and identification of zooplankton in estuary and coastal area of Mela vanjur in Nagapattinam district

Assessment of estuary and marine water quality is essential to check the suitability of a water source for the designated use. Therefore, the present study focuses on preliminary aspects of Physio-chemical parameters and identification of Zooplankton in the estuary and coastal area from Mela Vanjur, Nagapattinam, District, Tamil Nadu, India for this period of January 2023. Physico-chemical parameters like Smell, Flavour, Odour, Colour, Total Dissolved Solids, Turbidity, Temperature, Electrical Conductivity, pH, Salinity, Total alkalinity, Total hardness, Nitrite, Nitrate, NH3, Phosphate, Iron, Total Suspended Solids, COD, BOD, DO, were varied in both sample in the same month. The present study revealed that all the Physico-chemical parameters were more low, normal and high value, which may be due to the industrial effluents mixing up with the estuary. Suitable remedial measures should be taken to prevent the mixing of domestic sewage and discharge of effluent into the river to maintain the quality of the Vettar estuary. The present study revealed 15 genera of zooplankton from the estuary and marine water belonging to the four groups namely, 1. Cladocere: Daphnia sp. Ceriodaphnia sp, Alonella sp, Diaphanosoma sp, Moina sp, 2. Copepoda: Cyclops sp, Tropocyclops sp, Nauplius sp, Diaptomus sp, Heliodiaptomus sp, 3.Rotifera: Brachionus sp, Conochilus sp, Filinia sp, 4.Ostracoda: Cypris sp, Stenocypris sp. The present work provides substantial evidence that water quality analysis from Vettar estuary and marine water. From the study, it is evident that zooplankton may be a promising non-polluted depending on the ecological condition.

Small wetland‐fringed estuaries deliver disproportionately large carbon loads to the ocean

AbstractPrevious estimates of dissolved carbon export from estuaries focused on larger systems in the Northern Hemisphere, with little data for smaller tropical estuaries often fringed by intertidal wetlands. We investigated lateral export (outwelling) and transformation rates of dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and total alkalinity (TA) as well as CO2 emissions from 18 diverse Australian estuaries. Most estuaries acted as net sources for DOC (72%), DIC (83%), and TA (50%). On average, estuaries exported 120 ± 55 and 344 ± 150 mmol m−2 catchment yr−1 DOC and DIC, respectively. Estuarine CO2 emissions (33 ± 20 mmol m−2 estuary d−1) equalled 13% ± 16% of the dissolved lateral carbon export. Carbon export positively correlated with runoff, rain, and intertidal wetland cover, and negatively correlated with estuary and catchment area. Mangroves and saltmarshes cover < 1% of all catchments but can contribute 46% ± 11% of the DOC and 67% ± 13% of the DIC exported to the ocean. Upscaling our observations, Australian estuaries export 2.8 ± 2.2 TgC yr−1 DOC, 8.1 ± 6.2 TgC yr−1 DIC, and 0.7 ± 0.6 Tmol yr−1 TA. Small catchments (< 10 ha) making up 70% of all estuaries and accounting for 18% of the total freshwater flow provided 27% to the total dissolved carbon export. Overall, small tropical estuaries fringed by highly productive intertidal wetlands are hotspots of carbon exports and should be considered in marine carbon budgets.

Trade-Off and Coordination between Development and Ecological Protection of Urban Agglomerations along Rivers: A Case Study of Urban Agglomerations in the Shandong Section of the Lower Yellow River

Urban development of clusters situated along rivers significantly affects the health of the river ecosystems, the quality of urban environments, and the overall well-being of local communities. Ecosystem service supply value (ESSV) measures the delivery of ecosystem goods and services within a specific timeframe in a particular area. Using the lower Yellow River urban agglomeration (Shandong section) as a case, we comprehensively applied land use structure and intensity change analysis, quantitative calculation of ESS, and geographical probe methods to unveil ESS and its mechanism of response to the spatio-temporal evolution of the intensity of land use in urban agglomeration along the river. The key results were as follows: (1) Over the past two decades, farmland and construction land areas have continued to decrease and increase, respectively, with the intensity of land use change being highest from 2005 to 2010. (2) ESS has continued to rise over the past 20 years, with the income in 2020 being 11.142 billion yuan, an increase of 31.13%. The “low-value areas” are mainly concentrated in Liaocheng City, Dezhou City, and Tai’an City, which are characterized by predominantly flat terrains where farmland constitutes the principal land use type. Conversely, “high-value areas” are largely in the counties bordering the Yellow River, including the upper estuary in the north and the rugged, southeastern terrains. (3) Areas with concentrated ESSV were primarily localized in the northern estuary area and along the Yellow River in a scattered point-like pattern. The spatial distribution of hotspots has become increasingly concentrated, transitioning from points to planes. Conversely, cold spots initially increased in number before subsequently decreasing. Waterbody was the most sensitive ESSV-determining factor. (4) The spatial heterogeneity of ESSV emerges as a consequence of the interaction of multiple factors, and among these interactions, those involving NDVI and POP contain the greatest explanatory power. Our findings are expected to offer a scientific foundation for optimizing land spatial patterns and enhancing ecological management in the lower Yellow River region.

Land use conversion to uplands significantly increased the risk of antibiotic resistance genes in estuary area

Land use conversion in estuary wetlands may affect the transmission of antibiotic resistance genes (ARGs), while the risk rank of the ARGs and the change of clinically relevant ARGs under various land-use types are not well understood. This study used metagenomics to reveal the diversity and abundance of ARGs across five distinct land uses: reed wetland, tidal flat, grassland, agricultural land and fallow land, as well as their distribution and potential health risks. Results showed that high numbers of ARG subtypes and classes were detected irrespective of land-use types, notably higher in agricultural land (144 ARG subtypes). The most shared ARG subtypes were multidrug resistance genes across all the land uses (29 subtypes, 4.7 × 10−2-1.5 × 10−1 copies per 16S rRNA gene copy). Proteobacteria and Actinobacteria were primary ARG hosts, with 18 and 15 ARGs were found in both of them, respectively. The ARG subtype mdtB was the most dominant clinical ARG detected with 90 % amino acid identity. The change of ARGs exhibited a consistent trend across land uses in terms of health risk ranks, with the highest observed in fallow land and the lowest in reed wetland. This study reveals the distribution pattern of ARGs across various land-use types, and enhances our understanding of the potential health risks associated with ARGs in the context of coastal wetland conversion in estuary areas.

Integrated multi-omics analyses reveal microbial community resilience to fluctuating low oxygen in the East China sea

Climate change and eutrophication are accelerating ocean deoxygenation, leading to a global decline in oxygen levels. The East China Sea, frequently experiencing deoxygenation events, harbors diverse microbial communities. However, the response of these communities to the changing deoxygenation dynamics remains poorly understood. Here, we explored the composition and function of microbial communities inhabiting seawaters of the Changjiang Estuary and offshore areas. Our findings suggested that neutral processes significantly influenced the assembly of these communities. The overall bacterial composition demonstrated remarkable high stability across the oxygen gradient. Salinity exhibited a significantly stronger correlation with bacterial community structure than dissolved oxygen. Both metagenomics and metaproteomics revealed that all of the samples exhibited similar functional community structures. Heterotrophic metabolism dominated these sites, as evidenced by a diverse array of transporters and metabolic enzymes for organic matter uptake and utilization, which constituted a significant portion of the expressed proteins. O2 was the primary electron acceptor in bacteria even under hypoxic conditions, evidenced by expression of low- and high-affinity cytochrome oxidases. Proteins associated with anaerobic processes, such as dissimilatory sulfite reductases, were virtually undetectable. Untargeted liquid chromatography with tandem mass spectrometry analysis of seawater samples revealed a diverse range of dissolved organic matter (DOM) components in amino acids, lipids, organic acids, peptides, and carbohydrates, potentially fueling dominant taxa growth. Despite fluctuations in the abundance of specific genera, the remarkable similarity in community structure, function, and DOM suggests that this ecosystem possesses robust adaptive mechanisms that buffer against abrupt changes, even below the well-defined hypoxic threshold in marine ecosystem.

Simulation of typhoon-induced hydrodynamic conditions in the Hai Phong coastal area: a case study of Son Tinh typhoon 2012 and 2018

The Hai Phong coastal area is one of the places that is often affected by storms and tropical depressions, with significant impacts on hydrodynamics and geomorphological changes. The influence of typhoons on hydrodynamic conditions in the Hai Phong coastal area has yet to be thoroughly studied. Accordingly, the above study has evaluated the influence of storms with different trajectories on the hydrodynamic field in the Hai Phong coastal area under complex, non-linear impacts to contribute to a better understanding of the influence of storms on hydrodynamic processes and to improve research capacity on hydrodynamic regimes in coastal estuaries using modeling tools. Observational and reanalysis data from global sources were collected systematically and homogeneously to create open boundary conditions (time-serial) for the model. The NESTING method created sea boundary conditions for the model from another model with a larger grid outside. The Delft3D model system was set up with five vertical layers in Sigma coordinates and was validated, showing a fair agreement with measurement data at some places in the study area. Results of scenarios showed typhoons have an extreme impact on hydrodynamic conditions in the Hai Phong coastal area, especially raising the water level and increasing the flow velocity and wave height in the coastal area. Different typhoons effect the hydrodynamics differently, but they all share that the estuary areas with narrow channels are more strongly affected than the remaining areas. When the typhoons make landfall at the Lach Huyen estuary in Nam Trieu, the flow velocity can be up to 0.8–1.2 m/s (an increase of 0.5 m/s compared to the flow velocity in normal conditions), and the wave height can be up to 1.2–2.5 m (a rise of 0.4–2 m compared to the wave height in without typhoon).

Study of nitrogen and phosphorus nutrient dynamics in concentrated marine fish farming water environment in Long Son - Vung Tau

The nutritional content of N and P in concentrated marine fish farming water in the Cha Va - Long Son - Vung Tau estuary area increased sharply during 2013–2016; notably, the N-NH4+ content increased in 2017–2019. The N-NO2- and N-NO3- content in the dry season (0.051 mg/L and 0.190 mg/L) was higher than in the rainy season (0.044 mg/L and 0.133 mg/L). In contrast, the N-NH4+ and P-PO43- contents in the rainy season (0.321 mg/L and 0.1 mg/L) are higher than in the dry season (0.154 mg/L and 0.093 mg/L). The N and P nutrient dynamics in water fluctuate according to the semi-diurnal tide regime; the nutrient content decreases during high water - daytime, increases during low water in the evening, and is high during high water at night and in the morning, early the next day. In dry and rainy seasons, the N-NH4+ content is always the highest (0.024–0.761 mg/L) among the nitrogen-based nutritional parameters. N and P nutrients in water are correlated: N-NH4+ parameter pairs with Total P, N-NO2- with Total P, Total N with Total P, N-NO2- and N-NO3-, P-PO43- with Total P, and the parameter pair N-NO2- with P-PO43- have low positive correlation coefficients (r), from 0.1–0.21. Conversely, the parameter pairs N-NO3- and Total N, N-NO3- and N-NH4+, and N-NO2- and N-NH4+ have low negative correlation coefficients (r), from -0.12 to -0.26. From 2010–2021, the number of cages increased beyond planning, causing environmental pollution in the water in the farming area. The nutritional RQ value of the water is high at level 4 every year (very high risk of environmental pollution).

Landscape, demographic, and dispersal parameters influence the spread and establishment of an aquatic biological invasion

AbstractHuman‐mediated species introductions are contributing to the biotic homogenization of global flora and fauna. Despite extensive research, we lack simple methods of predicting how and where an introduced species will spread and establish, particularly in species with complex life histories in aquatic ecosystems. We predict that spread can be modeled simply using the characteristics of the invading population, specifically species growth rate and dispersal capacity. In addition, we predict that the establishment of introduced species should be explained by the characteristics of the receiving ecosystem. Using the brown trout (Salmo trutta) invasion on the Island of Newfoundland as a case study, we fit and test a reaction–diffusion model with brown trout population data collected from the literature. Next, we use statistical models to assess the influence of a suite of abiotic (conductivity, pH, turbidity, calcium), biotic (Atlantic salmon occurrence), and landscape (watershed relief, watershed area, distance to original introduction) variables on brown trout establishment (i.e., presence–absence) patterns. We find that observed coastal spread in Newfoundland is slow (~4.4 km/year), and that it lies on the lower end of the range of predictions made by the reaction–diffusion model parameterized based on the estimates of growth rate and movement from the literature (predicted spread range 1.4 to 92 km/year). Also, we did not find evidence for a relationship between abiotic or biotic variables and brown trout establishment. However, we did observe that landscape variables of the distance to trout introduction point and estuary area may explain establishment patterns along the south coast of Newfoundland. Our results suggest the importance of using population‐specific parameterization and the need to integrate regional landscape factors that are generally applicable across biological invasions (e.g., distance to introduction), and those that are more specific to the ecology of the invader (e.g., estuary area). Our study contextualizes the mechanisms that contribute to a slow invasion by an aquatic species with a complex life history and reveals that future studies need to integrate a variety of methods to elucidate the processes governing invasions.

Study on Design Method of Diversion Pier in Channel Entrance Area with Complex Flow Characteristics

The entrance area is the main way for ships to enter and exit the approach channel. During the navigation period, the approach channel, the entrance area and the connecting section should avoid turbulence, whirlpool and other bad flow conditions. When conditions are limited and cannot be avoided, engineering or non-engineering measures should be taken to make it harmless to ensure the efficiency and safety of shipping. Aiming at improving the navigation safety effect of the estuary area, this paper analyzes the effect of improvement measures under the actual navigable flow condition by establishing the flow information fitting model and the prediction model of diversion pier setting, and provides the design method and basis for the installation of diversion pier in the estuary area to be predicted. It enriches the model base and knowledge base of the channel entrance area with complex flow characteristics, which has important practical significance and engineering value for shipping safety and waterway management.

Quantitative analysis of aeolian dust incidence and diagnosis using a dynamic Bayesian network model: A case study of estuary area in central Taiwan

The presence of high concentrations of PM10 in aeolian dust within the estuary area of central Taiwan has been a focal point for air quality protection and remediation efforts over the past 15 years. This study explores the quantitative analysis of aeolian dust occurrences concerning various levels of PM10 concentration, aiming to offer early warning information to local communities and government agencies. Employing Dynamic Bayesian network (DBN) models, the research interrelates conditional probability dependencies among air quality and meteorological factors monitored in the downstream area of the Jhuoshuei River, predicting the probability distribution of aeolian dust events. The constructed DBNs demonstrate the inference of probability distributions of meteorological factors' states based on PM10 concentrations, enabling diagnostic analysis of meteorological conditions during high PM10 concentration dust events. The DBN models exhibit robust predictive ability, achieving an overall accuracy of 85.72% in validation and 85.8% in testing, with high discriminatory capacity that the area under the receiver operating characteristic curve (AUC) values of 0.924 and 0.915 during validation and testing, respectively. Sensitivity analysis highlights wind direction, wind speed, relative humidity as significant factors affecting PM10 concentrations. The probability of low PM10 concentrations was notably higher compared to higher concentrations, indicating effective aeolian dust remediation efforts. However, attention is warranted toward the 10% incidence of aeolian dust events deemed unhealthy or hazardous to human health. Diagnosis of meteorological conditions during high PM10 concentration events suggests low temperature, high wind speeds, and dry conditions, particularly with northeastern or southwestern winds, as conducive factors. This study underscores the physical relationship between meteorological factors and PM10 concentrations, employing DBNs to consider temporal relationships and uncertainties in data, aligning with human health impact standards proposed by the Ministry of Environment. Future research should incorporate soil and land surface conditions to provide a more comprehensive understanding of aeolian dust dynamics and mitigation strategies.

Aqueous VOCs in complex water environment of oil exploitation sites: Spatial distribution, migration flux, and risk assessment

Pollution of the aqueous environment by volatile organic compounds (VOCs) has caused increasing concerns. However, the occurrence and risks of aqueous VOCs in oil exploitation areas remain unclear. Herein, spatial distribution, migration flux, and environmental risks of VOCs in complex surface waters (including River, Estuary, Offshore and Aquaculture areas) were investigated at a typical coastal oil exploitation site. Among these surface waters, River was the most polluted area, and 1,2-Dichloropropane—which emerges from oil extraction activities—was the most prevalent VOC. Positive matrix factorization showed that VOCs pollution sources changed from oil exploitation to offshore disinfection activities along River, Estuary, Offshore and Aquaculture areas. Annual volatilization of VOCs to the atmosphere was predicted to be ∼34.42 tons, and rivers discharge ∼23.70 tons VOCs into the Bohai Sea annually. Ecological risk assessment indicated that Ethylbenzene and Bromochloromethane posed potential ecological risks to the aquatic environment, while olfactory assessment indicated that VOCs in surface waters did not pose an odor exposure risk. This study provides the first assessment of the pollution characteristics of aqueous VOCs in complex aqueous environments of oil exploitation sites, highlighting that oil exploitation activities can have nonnegligible impacts on VOCs pollution profiles.

Storm Liquefaction Deposits: A Possibility of Time Reversal in Sedimentary Strata of an Estuarial Coastal Area

Storm Liquefaction Deposits: A Possibility of Time Reversal in Sedimentary Strata of an Estuarial Coastal Area

PENGARUH TAMBAK SILVOFISHERY TERHADAP SIFAT FISIK TANAH MANGROVE SEBAGAI LAHAN KONSERVASI DAERAH MUARA SUNGAI BOGOWONTO KULON PROGO DAERAH ISTIMEWA YOGYAKARTA

The Bogowonto River estuary is a coastal area in the open water category because it faces the Indian Ocean directly, it has high wave energy, which will cause erosion and abrasion, and the presence of mangrove and pond ecosystems (silvofishery) can support the development of coastal areas as conservation land. So it is necessary to conduct research to examine the influence of soil physical properties on silvofishing and determine the types of mangroves in the Bogowonto River estuary area. The method used was a survey, where soil samples were tested at the Yogyakarta BPTP Laboratory and the Yogyakarta "Veteran" National Development University at a depth of 0–20 cm and 20–40 cm. Sampling was conducted in a zigzag method from the left (near the pond) and right sides of the river. The results of the research found that there are 2 types of mangroves, namely the Tan cang (Bruguiera sp.), which grows far from the coastline and close to fish pond areas (silvofishery), has a has a relatively stable pH, is dominated by clay texture, and has a low salinity level. White Mangrove (Avicennia sp.) grows near the coastline, with a dominant sandy loam texture, low-normal pH, and high salinity levels. Mangroves that grow along the southern river in the presence of silvofishery can help with the deposition process of mud that is transported along the river and maintain the sustainability of fish populations, and litter from mangroves tends to increase the organic matter content of the soil.