Article
Ecology
Christopher Craft
Summary: Restoration of tidal marshes has shown positive effects on vertical accretion, organic carbon sequestration, and nitrogen burial. This study compared a natural tidal salt marsh with a hydrologically restored salt marsh in Sapelo Island, Georgia, and found that the restored marsh had higher rates of accretion, carbon sequestration, and nitrogen burial. The restored marsh has been able to compensate for subsidence caused by dike construction, and current sea level rise and accretion rates support the ecosystem functions. However, the ability of the marshes to sequester carbon and bury nitrogen may be challenged with accelerated sea level rise.
ECOLOGICAL ENGINEERING
(2023)
Article
Environmental Sciences
Kelly Elschot, Martin J. Baptist, Marinka E. B. van Puijenbroek
Summary: A global concern for coastal ecosystems is the predicted rise in sea-level for which salt marshes must keep pace. Variables that control this elevation change need to be identified to predict the adaptability of marshes to future sea-level rise. Grazing by livestock can significantly reduce the annual rates of elevation gain and affect the future adaptability of salt marshes to grow vertically for rising sea levels. Trampling by grazing cattle, along with other factors like precipitation deficit and extreme drought, can lead to biocompaction and reduce the total elevation change.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Yajin Li, Zhigao Sun, Li Mao, Xingyun Hu, Bingbing Chen, Yanzhe Li
Summary: This study investigated the pollution levels, sources, and risks of heavy metals in sediments in the Fuzhou reach of the Min River. The results showed variations in heavy metal concentrations among different types of wetlands, with higher levels of lead and cadmium, which are highly toxic, requiring measures to control pollutant loading.
MARINE POLLUTION BULLETIN
(2022)
Article
Geography, Physical
Duncan M. FitzGerald, Christopher J. Hein, Jennifer E. Connell, Zoe J. Hughes, Ioannis Y. Georgiou, Alyssa B. Novak
Summary: This study investigated the vertical accretion of the Plum Island Sound marsh using Pb-210 and Cs-137 geochronology, revealing an average accretion rate of 3.13 mm/yr, which is 0.6 mm/yr higher than other areas in New England. While individual accretion rates showed no correlation with various parameters, projections suggest that the high marsh may transform into low marsh by 2050.
Article
Environmental Sciences
Anirban Mukhopadhyay, Rituparna Acharyya, Michal Habel, Indrajit Pal, Niloy Pramanick, Jyoti Prakash Hati, Manas Kumar Sanyal, Tuhin Ghosh
Summary: Satellite data reveals severe erosion on the riverbank of the Bhagirathi-Hugli River over the past decades (1990 to 2020), especially in the middle stretch. The estuary of the river is experiencing a continuous influx of sediment load from upstream erosion. The concentration of suspended sediment in the Hugli estuary was found to be higher before the monsoon season and in the southwestern section of the estuary. The impact of this sediment load contributes to deposition, resulting in the increase of effective island and Chars areas in the estuary.
Article
Geography, Physical
Luca Cortese, Sergio Fagherazzi
Summary: Wetlands in the Mississippi River Delta are degrading rapidly due to sea level rise and low sediment supply. This study in Terrebonne Bay, Louisiana, USA, used field data and aerial images to identify the drivers of marsh accretion and degradation. Marshes located inland in sheltered areas and those facing open water exhibit different patterns, with the distance to nearby channels and wave activity playing key roles. The study proposes a bimodal evolution trajectory for marshes in Terrebonne Bay, where marshes close to the bay rapidly accrete but suffer lateral erosion, while sheltered marshes accrete slowly and degrade due to insufficient sediment supply.
EARTH SURFACE PROCESSES AND LANDFORMS
(2022)
Article
Engineering, Civil
Zheyuan Du, Linlin Ge, Alex Hay-Man Ng, Xugang Lian, Qinggaozi Zhu, Finbarr G. Horgan, Qi Zhang
Summary: Following the operation of the middle route of the South-to-North Water Diversion Project, the total water transfer to Beijing has exceeded 5.0 km(3), leading to significant changes in Beijing's water use structure. While the SNWDP has helped alleviate land subsidence issues in Beijing, the main pressure on Beijing's water supply still comes from improved living standards, the popularization of water-using appliances, and rapid development in the accommodation and catering industries. With an expected increase in precipitation in the Beijing region over the next decade, there is a greater likelihood of rapid groundwater recovery, but climate extremes could potentially challenge the success of the SNWDP during certain dry periods.
JOURNAL OF HYDROLOGY
(2021)
Article
Geosciences, Multidisciplinary
Dariusz Ciszewski, Mateusz Sobucki
Summary: Land subsidence is closely related to water withdrawal and mining activities. It can increase the risk of flooding in river valleys, but can be mitigated through channel alignment and raising of flood dykes. This study focuses on the Chechlo River reach in southern Poland and examines the characteristics of sediments and channel geometry. The findings suggest that the sediments in the subsidence basin differ from those in unaffected river reaches in terms of stratigraphy and accretion rate.
Article
Multidisciplinary Sciences
Andrew J. Moodie, Jeffrey A. Nittrouer
Summary: The socioeconomic viability of fluvial-deltaic systems is constrained by the natural processes of these landforms, particularly avulsion. Artificial diversions can help mitigate land loss, but finding the optimal balance between cost and benefit is crucial. Urbanization in delta areas can create a positive feedback loop, enhancing infrastructure development and landscape preservation through diversions.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Environmental Sciences
Meagan J. Eagle, Kevin D. Kroeger, Amanda C. Spivak, Faming Wang, Jianwu Tang, Omar I. Abdul-Aziz, Khandker S. Ishtiaq, Jennifer O'Keefe Suttles, Adrian G. Mann
Summary: Coastal wetlands play a crucial role in storing atmospheric CO2 and responding to sea-level rise. This study shows that anthropogenic activities can disrupt wetland function, but restoration of tidal exchange can enhance elevation gain and carbon storage in these wetlands, improving their resilience to sea-level rise and climate benefits.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Tarandeep S. Kalra, Neil K. Ganju, Alfredo L. Aretxabaleta, Joel A. Carr, Zafer Defne, Julia M. Moriarty
Summary: Salt marshes are dynamic biogeomorphic systems that respond to external physical factors and internal processes. This study implemented new marsh dynamic processes in the COAWST model and verified them through idealized domains. Simulations showed that vertical accretion in marshes is dominated by organic deposition, while mineral estuarine sediments primarily deposit along the channel edges. The model's ability to predict sediment fate can be extended to simulate the impacts of future storms and sea-level rise scenarios on salt marsh ecomorphodynamics.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Ecology
Jacob Z. Cheng, John R. White
Summary: Coastal regions around the world, particularly the deltaic Louisiana in the USA, are experiencing significant land loss due to rising sea levels. The beneficial reuse of dredged sediments to create coastal marshes is a key effort to reverse this problem. However, there are differences in water quality improvement between newly created marshes and natural marshes, mainly related to organic matter content and denitrification rates in the soil.
ECOLOGICAL ENGINEERING
(2022)
Article
Environmental Sciences
Florin Zainescu, Edward Anthony, Alfred Vespremeanu-Stroe
Summary: This study explores the hydrodynamics of river mouths under various conditions through numerical simulations. The presence of river mouth bars and specific river discharge, wave heights, and directions are found to significantly influence the emergent hydrodynamics. The interactions between wave-driven circulation, river jets, and longshore currents at river mouths are complex and can be quantified by different parameters like the Dynamic diversion index.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Marine & Freshwater Biology
B. R. Evans, H. Brooks, C. Chirol, M. K. Kirkham, I Moller, K. Royse, K. Spencer, T. Spencer
Summary: This study investigated the relationship between the presence of different saltmarsh plants and the mechanical properties of the underlying substrate. The findings showed that vegetation can enhance sediment shear strengths, but the effect varies depending on the sediment type.
ESTUARINE COASTAL AND SHELF SCIENCE
(2022)
Review
Environmental Sciences
G. Paul Kemp, Elizabeth C. McDade, John W. Day, Robert R. Lane, Nancye H. Dawers, Jason N. Day
Summary: The Biloxi Marsh in Louisiana, located east of New Orleans, is a geologically stable wetland area benefiting from increased river sediment input, making it a prime candidate for restoration efforts. It has the potential to be restored to sustainability earlier and for a longer period compared to most other areas in the submerging Mississippi Delta. The lessons learned from restoration efforts in Biloxi Marsh can be applied to sustain valuable river deltas worldwide.