scholarly journals LARGE-SCALE PHYSICAL MODELING OF COASTAL PROTECTION PROVIDED BY A MODEL RHIZOPHORA MANGROVE FOREST

2018 ◽  
pp. 66
Author(s):  
Maria Maza ◽  
Javier L. Lara ◽  
Inigo J. Losada
Keyword(s):  
Large Scale ◽  
Root Systems ◽  
Coastal Protection ◽  
Mangrove Forests ◽  
Complex Root ◽  
Mangrove Species ◽  
Flow Energy ◽  
Aerial Roots ◽  
Waves And Currents ◽  
Mangrove Trees

Mangrove forests exist in intertidal areas of tropical zones and most are characterized by their complex root systems, which attenuates flow energy. Among the mangrove species, Rhizophora species is the most common one, representing approximately 90% of the world mangrove distribution (Ohira et al., 2013). In addition, this species is used in the majority of restoration projects. Rhizophora plants are characterized by their aerial roots, which form a network above the substrate. Although several studies have been performed in the last decade to characterize flow interaction with mangrove trees (e.g.: Zhang et al., 2015), there is still a lack of knowledge of the forces exerted on the trees and the attenuation produced under waves, currents and waves and currents flowing simultaneously action.

scholarly journals Geographic and environmental contributions to genomic divergence in mangrove forests

2020 ◽  
Author(s):  
Michele Fernandes da Silva ◽  
Mariana Vargas Cruz ◽  
João de Deus Vidal Júnior ◽  
Maria Imaculada Zucchi ◽  
Gustavo Maruyama Mori ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Avicennia Germinans ◽  
Global Changes ◽  
Mangrove Forests ◽  
Tidal Variation ◽  
Mangrove Species ◽  
Coastal Species ◽  
Precipitation Regimes ◽  
Isolation By Environment ◽  
Mangrove Trees

ABSTRACTAssessing the relative importance of geographic and environmental factors to the spatial distribution of genetic variation may provide relevant information about the processes that maintain genetic variation in natural populations. With a globally wide but very restricted habitat distribution, mangrove trees are an interesting model for studies aiming to understand the contributions of these factors. Mangroves occur along the continent-ocean interface of tropical and subtropical latitudes, regions considered inhospitable to many other plant types. Here, we used landscape genomics approaches to investigate the relative contributions of geographic and environmental variables to the genetic variation of two black mangrove species, Avicennia schaueriana and Avicennia germinans, along the South American coast. Using single nucleotide polymorphisms, our results revealed an important role of ocean currents in the gene flow of A. schaueriana and isolation by environment as the pattern that best explains the genetic differentiation of A. germinans. Additionally, for both species, we observed significant correlations between genetic variation with evidence of selection and precipitation regimes, tidal variation, solar radiation and temperature patterns. These discoveries expand our knowledge about the evolution of mangrove trees and provide important information to predict future responses of coastal species to the expected global changes for this century.

scholarly journals Evaluation of the Continuous Monitoring of Land Disturbance Algorithm for Large-Scale Mangrove Classification

2021 ◽  
Vol 13 (19) ◽  
pp. 3978
Author(s):  
Katie Awty-Carroll ◽  
Pete Bunting ◽  
Andy Hardy ◽  
Gemma Bell
Keyword(s):  
Continuous Monitoring ◽  
Large Scale ◽  
Data Availability ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Land Disturbance ◽  
Long Term Monitoring ◽  
The Impact ◽  
Term Monitoring

Mangrove forests are of high biological, economic, and ecological importance globally. Growing within the intertidal zone, they are particularly vulnerable to the effects of climate change in addition to being threatened on local scales by over-exploitation and aquaculture expansion. Long-term monitoring of global mangrove populations is therefore highly important to understanding the impact of these threats. However, data availability from satellites is often limited due to cloud cover. This problem can be mitigated using a season-trend modelling approach such as Continuous Monitoring of Land Disturbance (COLD). COLD operates by using every available observation on a pixel-wise basis, removing the need for whole cloud free images. The approach can be used to better classify land cover by taking into account the underlying seasonal variability, and can also be used to extrapolate between data points to obtain more accurate long term trends. To demonstrate the utility of COLD for global mangrove monitoring, we applied it to five study sites chosen to represent a range of mangrove species, forest types, and quantities of available data. The COLD classifier was trained on the Global Mangrove Watch 2010 dataset and applied to 30 years of Landsat data for each site. By increasing the period between model updates, COLD was successfully applied to all five sites (2253 scenes) in less than four days. The method achieved an overall accuracy of 92% with a User’s accuracy of 77% and a Dice score of 0.84 for the mangrove class. The lowest User’s accuracy was for North Kalimantan (49.9%) due to confusion with mangrove palms. However, the method performed extremely well for the Niger Delta from the 2000s onwards (93.6%) despite the absence of any Landsat 5 data. Observation of trends in mangrove extent over time suggests that the method was able to accurately capture changes in extent caused by the 2014/15 mangrove die-back event in the Gulf of Carpentaria and highlighted a net loss of mangroves in the Matang Forest Reserve over the last two decades, despite ongoing management. COLD is therefore a promising methodology for global, long-term monitoring of mangrove extent and trends.

scholarly journals ASSESSMENT OF MANGROVE ECOSYSTEM POTENCY AND ITS UTILIZATION IN DOMPU REGENCY COASTAL WATERS, WEST NUSA TENGGARA PROVINCE USING SATELLITE IMAGERY APPLICATION

Jurnal Segara ◽  
2019 ◽  
Vol 15 (2) ◽  
Author(s):  
Yulius Yulius ◽  
Syahrial Nur Amri ◽  
August Daulat ◽  
Sari Indriani Putri
Keyword(s):  
Satellite Imagery ◽  
Coastal Waters ◽  
Mangrove Forest ◽  
Satellite Image ◽  
Mangrove Ecosystem ◽  
Coastal Vegetation ◽  
Coastal Protection ◽  
Landsat 8 ◽  
Mangrove Forests ◽  
Mangrove Species

Mangrove forests are tropical coastal vegetation communities, which has the ability to grow in coastal area with tidal and muddy environment. Several functions of mangrove forest such as ecological functions can be used for coastal protection, trapping sediment and strengthen the coastal ecosystems. Coastal waters in Dompu Regency, West Nusa Tenggara have natural mangrove ecosystem with a huge potency and advantages to the region. This study aimed to understand the condition of mangrove ecosystem based on satellite image analysis of Landsat 8 Operational Land Imager (OLI) in 2014 and assess the potency, information related to the utilization by community. Data collection in this study were combined from satellite imagery interpretation with interview and questionnaires. The results showed that the mangrove forest extent in Dompu Regency Coastal Waters were about 90,631 ha with uniformity index 0.68 (medium uniformity). Two mangrove species were found in the region namely Rhizopora stylosa and Rhizopora apiculata and used by the community for several purposes such as firewood, natural coastal protection from tidal, waves and abrasion, also for crabs and fish spawning ground.

scholarly journals Can Strict Protection Stop the Decline of Mangrove Ecosystems in China? From Rapid Destruction to Rampant Degradation

Forests ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 55 ◽  
Author(s):  
Wenqing Wang ◽  
Haifeng Fu ◽  
Shing Yip Lee ◽  
Hangqing Fan ◽  
Mao Wang
Keyword(s):  
Large Scale ◽  
Higher Plants ◽  
Mangrove Ecosystem ◽  
Common Species ◽  
Mangrove Forests ◽  
Ecological Processes ◽  
Mangrove Species ◽  
Bruguiera Gymnorhiza ◽  
Restoration Strategies ◽  
Mangrove Conservation

China has lost about 50% of its mangrove forests from 1950 to 2001. Since 2001, mangrove forest area has increased by 1.8% per year due to strict protection of the remaining mangrove forests and large-scale restoration. By 2019, 67% of the mangrove forests in China had been enclosed within protected areas (PAs). In terms of the proportion of PAs of mangrove forests, China has achieved the conservation target of “Nature Needs Half”. The ongoing degradation of mangrove forests was assessed at the species, population, community and ecosystem levels. The results show that despite the strict protection, the remaining mangrove forests are suffering extensive degradation due to widespread anthropogenic disturbance. Of the 26 mangrove species, 50% are threatened with extinction, a proportion higher than the average for all higher plants in China (10.8%). Local extinction of some common species like Bruguiera gymnorhiza is widespread. About 53% of the existing mangrove areas were dominated by low-intertidal pioneer species. Consequently, the carbon stock in vegetation has decreased by 53.1%, from 21.8 Tg C in the 1950s to 10.2 Tg C in 2019. Meanwhile, there is an estimated 10.8% concomitant decrease in the carbon sequestration rate. The root cause for this degradation in China is seawall construction because most mangroves are outside seawalls in China. Without fundamental changes in protection and restoration strategies, mangrove forests in China will continue to degrade in spite of strict protection and large-scale restoration. Future mangrove conservation effort should aim to preserve the diversity of both the biota and the ecological processes sustaining the mangrove ecosystem. A few suggestions to raise the effectiveness of mangrove conservation actions were provided.

Analysis of East Surabaya Shoreline Determination Using Tidal Data, Image Satellite and RTK-GNSS

2017 ◽  
Vol 862 ◽  
pp. 41-45 ◽  
Author(s):  
Khomsin
Keyword(s):  
Large Scale ◽  
Global Network ◽  
Coastal Protection ◽  
Mangrove Forests ◽  
Residential Areas ◽  
Conservation Area ◽  
Image Satellite ◽  
Catchment Areas ◽  
Tidal Data ◽  
The Impact

Coastal areas often experience changes in function, region supposed to be conservation area or coastal protection forests, as water catchment areas and habitats of mangrove forests have been turned into region large-scale housing, residential, industrial, ware housing and so on. Coastal area of Surabaya, especially in the East Surabaya, the reclaimed much influenced by several factors, including results from land fill for various purposes (residential areas, factories, bussiness and etc.) and caused by the sedimentation of the estuary lead the emergence of mainland. The impact of the reclamation both landfill or natural sedimentation certainly have an impact on shoreline.Based on the explanation of the law of local government No. 23, 2014 Article 6 [1], the meant of shoreline is the boundary meeting between the highest sea level and the mainland. The use of shoreline in this provision is intended for the determination of the administrative area in the management marine areas. Where is the position of the East Surabaya shoreline recently?This paper will answer the question to determine the East Surabaya shoreline using tidal data, image satellite and Real Time Kinematic-Global Network Satellite System (RTK-GNSS). The result can be used by Surabaya Government to manage buffer and marine zone especially in the eastern part of Surabaya.

Restoring barrier habitat in Louisiana to compensate for natural resource injuries: Shell Island and Chenier Ronquille Barrier Restoration Projects

Shore & Beach ◽  
2020 ◽  
pp. 65-71
Author(s):  
Whitney Thompson ◽  
Christopher Paul ◽  
John Darnall
Keyword(s):  
Gulf Of Mexico ◽  
Natural Resource ◽  
Large Scale ◽  
Barrier Island ◽  
Deepwater Horizon ◽  
Coastal Protection ◽  
Restoration Project ◽  
Island Restoration ◽  
Barataria Basin ◽  
Outer Coast

Coastal Louisiana received significant funds tied to BP penalties as a result of the Deepwater Horizon incident. As it is widely considered that the State of Louisiana sustained most of the damage due to this incident, there has been a firm push to waste no time in implementing habitat restoration projects. Sustaining the land on the coast of Louisiana is vital to our nation’s economy, as several of the nation’s largest ports are located on the Gulf coast in Louisiana. In addition, the ecosystems making up the Louisiana coast are important to sustain some of the largest and most valuable fisheries in the nation. Funded by BP Phase 3 Early Restoration, the goals of the Natural Resource Damage Assessment (NRDA) Outer Coast Restoration Project are to restore beach, dune, and marsh habitats to help compensate spill-related injuries to habitats and species, specifically brown pelicans, terns, skimmers, and gulls. Four island components in Louisiana were funded under this project; Shell Island Barrier Restoration, Chenier Ronquille Barrier Island Restoration, Caillou Lake Headlands Barrier Island Restoration, and North Breton Island Restoration (https://www. gulfspillrestoration.noaa.gov/louisiana-outer-coast-restoration, NOAA 2018). Shell Island and Chenier Ronquille are critical pieces of barrier shoreline within the Barataria Basin in Plaquemines Parish, Louisiana. These large-scale restoration projects were completed in the years following the Deepwater Horizon incident, creating new habitat and reinforcing Louisiana’s Gulf of Mexico shoreline. The Louisiana Coastal Protection and Restoration Authority (CPRA) finished construction of the Shell Island NRDA Restoration Project in 2017, which restored two barrier islands in Plaquemines Parish utilizing sand hydraulically dredged from the Mississippi River and pumped via pipeline over 20 miles over levees and through towns, marinas, and marshes to the coastline. The National Marine Fisheries Service (NMFS) also completed the Plaquemines Parish barrier island restoration at Chenier Ronquille in 2017 utilizing nearshore Gulf of Mexico sediment, restoring wetland, coastal, and nearshore habitat in the Barataria Basin. A design and construction overview is provided herein.

scholarly journals Configuration of Allocated Mangrove Areas and Protection of Mangrove-Dominated Muddy Coasts: Knowledge Gaps and Recommendations

2021 ◽  
Vol 13 (11) ◽  
pp. 6258
Author(s):  
Nguyen Tan Phong ◽  
Thai Thanh Luom
Keyword(s):  
Practical Knowledge ◽  
South East Asia ◽  
Mangrove Forests ◽  
Sediment Trapping ◽  
Mangrove Species ◽  
Second Stage ◽  
Seaward Side ◽  
Local Livelihoods ◽  
Full Consideration ◽  
Technical Recommendations

Mangrove-dominated muddy coasts have been allocated for developing livelihood models, particularly in developing countries. Uncontrolled allocation causes the mangrove forests to be vulnerable and even severely eroded. Restoration of vulnerable and eroded coastal areas has been merely conservation-driven, leaving livelihood-oriented mangrove forests unprotected. As a consequence, mangrove-dominated muddy coasts have not been well-protected. How livelihood-oriented mangrove forests are configured towards protecting coasts and protecting local livelihoods remains a challenge. This study employed a critical review for addressing this matter. The results reveal that there is limited practical knowledge of configuring livelihood-oriented models for protecting the coasts. The configuration process reported in this study is merely based on technical recommendations in South East Asia to date. The recommended configuration commences with the first stage of voluntarily designating a certain percentage of allocated forests on the seaward side to protect coasts, relocating livelihood models in the gaps among current stands of mangrove forests landward. Abandoned ponds are ecologically restored using sediment trapping structures for providing suitable substrate for promoting regrowth of local mangrove species as the second stage, followed by designation of an appropriate percentage as mangrove belts on the seaward side. The two-step configuration is highly likely to be replicable and applicable nationally and regionally due to full consideration of different political, sociocultural, and environmental characteristics in Vietnam and Indonesia.

scholarly journals Forest Structure and Projections of Avicennia germinans (L.) L. at Three Levels of Perturbation in a Southwestern Gulf of Mexico Mangrove

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 989
Author(s):  
Basáñez-Muñoz Agustín de Jesús ◽  
Jordán-Garza Adán Guillermo ◽  
Serrano Arturo
Keyword(s):  
Size Structure ◽  
Transition Probabilities ◽  
High Sensitivity ◽  
Avicennia Germinans ◽  
Mangrove Forests ◽  
Mangrove Species ◽  
Adult Trees ◽  
Mangrove Dynamics ◽  
Projection Matrices ◽  
Partial Tree

Mangrove forests have declined worldwide and understanding the key drivers of regeneration at different perturbation levels can help manage and preserve these critical ecosystems. For example, the Ramsar site # 1602, located at the Tampamachoco lagoon, Veracruz, México, consists of a dense forest of medium-sized trees composed of three mangrove species. Due to several human activities, including the construction of a power plant around the 1990s, an area of approximately 2.3 km2 has suffered differential levels of perturbation: complete mortality, partial tree loss (divided into two sections: main and isolated patch), and apparently undisturbed sites. The number and size of trees, from seedlings to adults, were measured using transects and quadrats. With a matrix of the abundance of trees by size categories and species, an ordination (nMDS) showed three distinct groups corresponding to the degree of perturbation. Projection matrices based on the size structure of Avicennia germinans showed transition probabilities that varied according to perturbation levels. Lambda showed growing populations except on the zone that showed partial tree loss; a relatively high abundance of seedlings is not enough to ensure stable mangrove dynamics or start regeneration; and the survival of young trees and adult trees showed high sensitivity.

scholarly journals Large-Scale Laboratory Experiments on Mussel Dropper Lines in Ocean Surface Waves

2020 ◽  
Vol 9 (1) ◽  
pp. 29
Author(s):  
Rebekka Gieschen ◽  
Christian Schwartpaul ◽  
Jannis Landmann ◽  
Lukas Fröhling ◽  
Arndt Hildebrandt ◽  
...  
Keyword(s):  
Large Scale ◽  
Laboratory Experiments ◽  
Blue Mussel ◽  
Farming Systems ◽  
Quality Parameter ◽  
Large Wave ◽  
Marine Aquaculture ◽  
Ocean Surface Waves ◽  
Wave Flume ◽  
Waves And Currents

The rapid growth of marine aquaculture around the world accentuates issues of sustainability and environmental impacts of large-scale farming systems. One potential mitigation strategy is to relocate to more energetic offshore locations. However, research regarding the forces which waves and currents impose on aquaculture structures in such conditions is still scarce. The present study aimed at extending the knowledge related to live blue mussels (Mytilus edulis), cultivated on dropper lines, by unique, large-scale laboratory experiments in the Large Wave Flume of the Coastal Research Center in Hannover, Germany. Nine-months-old live dropper lines and a surrogate of 2.0 m length each are exposed to regular waves with wave heights between 0.2 and 1.0 m and periods between 1.5 and 8.0 s. Force time histories are recorded to investigate the inertia and drag characteristics of live mussel and surrogate dropper lines. The surrogate dropper line was developed from 3D scans of blue mussel dropper lines, using the surface descriptor Abbott–Firestone Curve as quality parameter. Pull-off tests of individual mussels are conducted that reveal maximum attachment strength ranges of 0.48 to 10.55 N for mussels that had medium 3.04 cm length, 1.60 cm height and 1.25 cm width. Mean drag coefficients of CD = 3.9 were found for live blue mussel lines and CD = 3.4 for the surrogate model, for conditions of Keulegan–Carpenter number (KC) 10 to 380, using regular wave tests.

scholarly journals Understanding epistemic uncertainty in large-scale coastal flood risk assessment for present and future climates

2018 ◽  
Author(s):  
Michalis I. Vousdoukas ◽  
Dimitrios Bouziotas ◽  
Alessio Giardino ◽  
Laurens M. Bouwer ◽  
Evangelos Voukouvalas ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Flood Risk ◽  
Large Scale ◽  
Epistemic Uncertainty ◽  
Coastal Protection ◽  
Flood Risk Assessment ◽  
Coastal Flood ◽  
Coastal Flood Risk ◽  
The Impact

Abstract. An upscaling of flood risk assessment frameworks beyond regional and national scales has taken place during recent years, with a number of large-scale models emerging as tools for hotspot identification, support for international policy-making and harmonization of climate change adaptation strategies. There is, however, limited insight on the scaling effects and structural limitations of flood risk models and, therefore, the underlying uncertainty. In light of this, we examine key sources of epistemic uncertainty in the Coastal Flood Risk (CFR) modelling chain: (i) the inclusion and interaction of different hydraulic components leading to extreme sea-level (ESL); (ii) inundation modelling; (iii) the underlying uncertainty in the Digital Elevation Model (DEM); (iv) flood defence information; (v) the assumptions behind the use of depth-damage functions that express vulnerability; and (vi) different climate change projections. The impact of these uncertainties to estimated Expected Annual Damage (EAD) for present and future climates is evaluated in a dual case study in Faro, Portugal and in the Iberian Peninsula. The ranking of the uncertainty factors varies among the different case studies, baseline CFR estimates, as well as their absolute/relative changes. We find that uncertainty from ESL contributions, and in particular the way waves are treated, can be higher than the uncertainty of the two greenhouse gas emission projections and six climate models that are used. Of comparable importance is the quality of information on coastal protection levels and DEM information. In the absence of large-extent datasets with sufficient resolution and accuracy the latter two factors are the main bottlenecks in terms of large-scale CFR assessment quality.

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