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Sketches of the 2‐D model domain with a low permeable upper layer (light gray color) and a high permeable bottom layer (dark gray color with black dots). The surface elevation at the ocean boundary (right side) is 0 m. The elevation at the upland boundary is 1.8 m for the milder upslope domain and 4.8 m for the steeper upslope domain. MHTL stands for the mean highest tide level and MSL is the mean sea level. The present‐day MSL is at the 0 m level. h at the left side of the domain indicates the upland groundwater level. Three upland groundwater level scenarios are used: h = 1.3 m (present‐day level), h = 1.8 (reflecting future wetter climate), and h = 0.9 m (reflecting future drier climate or more groundwater extraction).
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Coastal saltwater intrusion (SWI) is one key factor that affects the hydrology, ecology, and biogeochemistry of coastal ecosystems. Future climate change, especially intensified sea level rise (SLR), is expected to trigger SWI to encroach coastal freshwater aquifers more intensively. Numerous studies have investigated decadal/century scale SWI unde...
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Sediment transport modeling (STM) is a potentially effective tool for estimating the magnitude of tsunamis and earthquakes without historical records. However, the application of STM to prehistorical tsunamis is challenging because of multiple uncertainties in topography and roughness. Along the coast of Hidaka, Hokkaido, Japan, there is potential...
Citations
... Transport of organic matter and nutrients below and at the surface is then influenced by heterogeneous soil properties and surface morphology, while microbial activity also plays an important role in mediating carbon and nutrient transformations in the coastal TAIs (Ganju et al., 2019;Lee et al., 2006;Waska et al., 2019). In addition, coastal vegetation in wetlands and uplands also shapes hydrological and biogeochemical processes through transpiration and its interactions with soil, water, and microbes (Krauss et al., 2018;LaFond-Hudson & Sulman, 2023;McDowell et al., 2022;Smith & Kirwan, 2021;Spiteri et al., 2008;Wang et al., 2020;Xiao et al., 2019;Zhang et al., 2022). Terrestrial organic matter can contribute additional carbon for biogeochemical processes, and salt marshes might serve as significant carbon source (Xin et al., 2022). ...
... Numerical models have been increasingly used to understand the coastal TAIs processes (Fang et al., 2022;Li et al., 2020;Yabusaki et al., 2020;Zhang et al., 2022). However, these models lack an integrated framework that couples surface and subsurface flow and reactive transport processes with ecological processes associated with terrestrial and wetland vegetation for the coastal TAIs. ...
Plain Language Summary
The hydrological environment of vegetated coastal ecosystems is directly influenced by precipitation and seawater flooding, which mediates biogeochemical processes within these areas. However, the specific effects of dynamic precipitation and flooding on oxidation‐reduction conditions in these complex terrestrial‐aquatic interfaces (TAIs) are poorly understood, especially when considering the ecological processes of above‐ground plants. To address this gap, this study used integrated process‐based models, the Advanced Terrestrial Simulator (ATS) and PFLOTRAN, to examine the effects of hydrological and ecological controls on biogeochemical reactions and exchange fluxes across a TAIs transect spanning from a coastal upland forest and salt marsh to the open seawater. Our numerical experiments showed that the mixing of different waters within the TAIs significantly influenced the spatial and temporal variability in exchange fluxes across this interface along with the spatial extent of oxic subsurface zones. The interface between the oxic and anoxic zones shifts in response to periodic fluctuations in tidal elevations as higher tides drive more oxygenated water toward the TAIs. Meanwhile, vegetation evapotranspiration removes more water from the subsurface during warm summer months, leading to larger exchange fluxes across the TAIs. Reaction rate parameters that depend on the interactions between the soil and microbes have a large effect on carbon and oxygen consumption represented in our models. A higher aerobic respiration rate results in larger hypoxic and anoxic zones because the dissolved oxygen is consumed more quickly. Our modeling‐based study provided insights into the mechanisms that control the exchange fluxes and cycling of carbon and nitrogen at coastal TAIs, which can be used to inform potential management strategies for mitigating the impacts of climate change on these ecosystems.
... Another significant effect of climate change on lagoon water quality is sea-level rise. Rising sea levels can cause saltwater intrusion, which occurs when saltwater infiltrates freshwater supplies [28]. This influx can cause increased salinity in lagoons, making them less welcoming to freshwater species and affecting the overall ecosystem composition. ...
Lagoons are an environmentally and economically important ecosystem in Sri Lanka. They support
a range of natural services that are highly valued by society including fishing, storm protection,
provide habitat for fauna and flora, tourism, and others. However, it is often subjected to natural
and man-made changes. Contamination of surface water of lagoons has become a common
phenomenon worldwide due to the rapid industrialization, urbanization and development in
agriculture and mining. Excess nutrients, sea water intrusion, and heavy metal discharge from
agricultural and industrial wastage together with land reclamation are found to be the most
serious problems confronting the sustainability of Sri Lankan lagoons. Several toxic elements
finally end up in lagoons from various sources deteriorating the quality of water and threatening
the lives of organisms living in. Despite increasing public sensitization, water pollution continues
to generate unpleasant implications for health and community development. Therefore, the
protection of water quality and the aquatic ecosystem is of utmost importance to prevent water
pollution and degradation of brackish water resources in Sri Lanka. It is important to continually
investigate the quality of surface and groundwater of lagoons to check the influence of growing
population, urbanization and industrialization on it.
Keywords: Contamination, Lagoons, Pollutants, Urbanization, Water quality
... There are multiple ways in which climate change can impact the frequency and intensity of salinity events. Rising sea levels can also result in more saltwater infiltrating coastal aquifers [137], which may cause an increase in groundwater salinity. Furthermore, climate change can indirectly influence salinity levels by affecting other factors contributing to salinization, such as agricultural practices and land use changes. ...
Téllez-Isaías, G.; Khalifa, N.E.; Abdelnour, S.A.; Eissa, M.E.H.; Al-Farga, A.; Dighiesh, H.S.; et al. A Global Analysis of Climate Change and the Impacts on Oyster Diseases. Sustainability 2023, 15, 12775.
... There are multiple ways in which climate change can impact the frequency and intensity of salinity events. Rising sea levels can also result in more saltwater infiltrating coastal aquifers [137], which may cause an increase in groundwater salinity. Furthermore, climate change can indirectly influence salinity levels by affecting other factors contributing to salinization, such as agricultural practices and land use changes. ...
Recently, global demand for seafood such oysters is increasing as consumers seek healthy and nutritive alternatives to a diet dominated by animal protein. This trend is attributed to the growing interest in sustainable seafood strategies and a surge in customer demand. Despite oysters being one of the most promising seafoods, the oyster industry faces various challenges, such as increased infectious diseases promoted by climate change, pollution, and environmental burdens. Hence, the industry’s current challenges must be addressed to ensure long-term viability. One of the current challenges in the production industry (in response to climate change) is mortality or poor product quality from microbial infection. This review reveals that climate change fosters pathogen development, significantly impacting disease spread, host susceptibility, and the survival rates of oysters. Rising temperatures, driven by climate, create favourable conditions for bacteria and viruses to multiply and spread quickly, making oysters more susceptible to diseases and ultimately adversely affecting the oyster industry. Climate-induced changes in oyster-associated microbes and pathogens, coupled with disruptions in biochemical pathways and physiological functions, can lead to increased disease outbreaks and reduced survival in the industry, impacting production and profitability. These adverse effects could result in decreased oyster supply, potentially affecting seafood markets and prices, and necessitate additional investments in disease management strategies. This review identifies and highlights how aquatic pathogens promoted by climate change will affect the oyster industry on a global scale. This review also presents an in-depth global assessment of climate change’s impacts on oysters relative to their disease exposure and pathogen spread and identifies possible future directions.
... Transport of organic matter and nutrients below and at the surface is then influenced by heterogeneous soil properties and surface morphology, while microbial activity also plays an important role in mediating carbon and nutrient transformations in coastal TAIs [Lee et al., 2006;Waska et al., 2019;Ganju et al., 2019]. In addition, coastal vegetation in wetlands and uplands also shapes hydrological and biogeochemical processes through transpiration and its interactions with soil, water, and microbes [LaFond-Hudson and Sulman, 2023;McDowell et al., 2022;Smith and Kirwan, 2021;Zhang et al., 2022;Wang et al., 2020;Krauss et al., 2018]. Organic matter of terrestrial origin may provide an additional source of carbon for biogeochemical transformations, while salt marshes may be important carbon sinks [Xin et al., 2022]. ...
... Numerical models have been increasingly used to understand the TAI processes [Fang et al., 2022;Yabusaki et al., 2020;Li et al., 2020;Zhang et al., 2022]. However, these models lack an integrated framework that couples surface and subsurface flow and reactive transport processes with ecological processes associated with terrestrial and wetland vegetation for coastal TAI systems. ...
The complex interactions among soil, vegetation, and site hydrologic conditions driven by precipitation and tidal cycles control biogeochemical transformations and bi-directional exchange of carbon and nutrients across the terrestrial-aquatic interfaces (TAIs) in the coastal regions. This study uses a highly mechanistic model, ATS-PFLOTRAN, to explore how these interactions impact the material exchanges and carbon and nitrogen cycling along a TAI transect in the Chesapeake Bay region that spans zones of open water, coastal wetland and upland forest. Several simulation scenarios are designed to parse the effects of the individual controlling factors and the sensitivity of carbon cycling to reaction constants derived from laboratory experiments. Our simulations revealed a hot zone for carbon cycling under the coastal wetland and the transition zones between the wetland and the upland. Evapotranspiration is found to enhance the exchange fluxes between the surface and subsurface domains, resulting in higher dissolved oxygen concentration in the TAI. The transport of organic carbon decomposed from leaves provides additional source of organic carbon for the aerobic respiration and denitrification processes in the TAI, while the variability in reaction rates mediated by microbial activities plays a dominant role in controlling the heterogeneity and dynamics of the simulated redox conditions. This modeling-focused exploratory study enabled us to better understand the complex interactions of various system components at the TAIs that control the hydro-biogeochemical processes, which is an important step towards representing coastal ecosystems in larger-scale Earth system models.
... In addition, some uncertainties exist in simply using the static digital elevation model (DEM) for the study period . The geomorphologic change of coastal marshes may have some impacts on seawater propagation, thereby affecting coastal freshwater-saltwater interaction (Zhang et al., 2022b). The RF models used in this study are exemplary for investigating the combined effects and relative importance of hydrogeomorphic variables impacting coastal wetland downgrading, although the models cannot illustrate the detailed physiological processes behind the downgrading processes. ...
Coastal wetlands provide critical ecosystem services but are experiencing disruptions caused by inundation and saltwater intrusion under intensified climate change, sea-level rise, and anthropogenic activities. Recent studies have shown that these disturbances downgraded coastal wetlands mainly through affecting their hydrological processes. However, research on what is the most critical driver for wetland downgrading and how it affects coastal wetlands is still in its infancy. This study examined drivers of three types of wetland downgrading, including woody wetland loss, emergent herbaceous wetland loss, and woody wetlands converting to emergent herbaceous wetlands. By using random forest classification models for the wetland ecosystems in the Alligator River National Wildlife Refuge, North Carolina, USA, during 1995-2019, we determined the relative importance of different hydrogeomorphic processes and the dominant variables in driving the wetland downgrading. Results showed that random forest classification models were accurate (> 97 % overall accuracy) in classifying wetland downgrading. Multiple hydrogeomorphic variables collectively contributed to the coastal wetland downgrading. However, the dominant control factors varied across different types of wetland downgrading. Woody wetlands were most susceptible to saltwater intrusion and were likely to downgrade if the saltwater table was shallower than 0.2 m below the land surface. In contrast, emergent herbaceous wetlands were most vulnerable to inundation and drought. The favorable groundwater table for emergent herbaceous wetlands was between 0.34 m above the land surface and 0.32 m below the land surface, beyond which the emergent herbaceous wetland tended to disappear. For downgraded woody wetlands, their distance to canals/ditches played a crucial role in determining their fates after downgrading. The machine learning approach employed in this study provided critical knowledge about the thresholds of hydrogeomorphic variables for the downgrading of different types of coastal wetlands. Such information can help guide effective and targeted coastal wetland conservation, management, and restoration measures.
... Table S2 summarizes the other sediment parameter values. Similar to many other numerical studies that examined sediment dynamics in coastal vegetated areas, we represented the impact of vegetation on sedimentation through the reduced bed shear stress that regulates 305 sediment erosion (e.g., Zhang et al., 2019;Zhu et al., 2020;Breda et al., 2021;Zhang et al., 2022). We did not activate processes of elevation change and bed load in the simulation. ...
... We also note that the sediment erosion rate is determined solely by bed shear stress in the present hydrodynamic-sediment transport model, similar to most modeling studies (e.g., Zhang et al., 2022). Several recent experimental studies have shown that the turbulence generated by vegetation could contribute to sediment erosion, and that turbulence represented by TKE may 510 be a better predictor of erosion rate than bed shear stress (Tinoco and Coco, 2016;Yang and Nepf, 2018;Liu et al., 2021), a process not considered in this study. ...
In hydrodynamic models, vegetation is commonly approximated as an array of vertical cylinders to represent its impacts on flow and sediment transport. However, this simple approximation may not be valid in the case of Rhizophora mangroves that have complicated three-dimensional root structures. Here, we present a new model to represent the impacts of Rhizophora mangroves on flow and sediment transport in hydrodynamic models. The model explicitly accounts for the effects of the three-dimensional root structures on flow and turbulence, as well as the effects of two different length scales of vegetation-generated turbulence characterized by stem diameter and root diameter. The model employs an empirical model for the Rhizophora root structures that can be applied using basic vegetation parameters (mean stem diameter and tree density), without rigorous measurements of the root structures. We showed that compared to the conventional approximation using an array of cylinders, the new model significantly improves the predictability of velocity, turbulent kinetic energy, and bed shear stress measured in a model and a real Rhizophora mangrove forest. The model further suggested the high efficiency of the three-dimensional root structures of Rhizophora mangroves on sedimentation, which allows a relatively high sediment supply to the forest but effectively regulates sediment erosion through reduced bed shear stress, compared to cylinder arrays that exhibit equivalent sediment supply or sediment retention. The presented model could be a fundamental tool to advance our understanding of the sedimentary processes in Rhizophora mangrove forests which are linked to mangroves’ vulnerability and ecosystem service.
