Editorial

3 pages, 187 KiB

Open AccessEditorial

Applied Sciences: “Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development”

by Marta Pérez-Arlucea and Rita González-Villanueva

Appl. Sci. 2021, 11(1), 119; https://0-doi-org.brum.beds.ac.uk/10.3390/app11010119 - 24 Dec 2020

Cited by 1 | Viewed by 1116

A large percentage of the world’s population lives along the coastal zones, with more than half of the world’s population living in coastal areas [...] Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

Research

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20 pages, 10770 KiB

Open AccessArticle

Wind-Driven Hydrodynamics in the Shallow, Micro-Tidal Estuary at the Fangar Bay (Ebro Delta, NW Mediterranean Sea)

by Marta F-Pedrera Balsells, Manel Grifoll, Manuel Espino, Pablo Cerralbo and Agustín Sánchez-Arcilla

Appl. Sci. 2020, 10(19), 6952; https://0-doi-org.brum.beds.ac.uk/10.3390/app10196952 - 04 Oct 2020

Cited by 9 | Viewed by 2198

Abstract

This article investigates water circulation in small-scale (~10 km²), shallow (less than 4 m) and micro-tidal estuaries. The research characterizes the hydrodynamic wind response in these domains using field data from Fangar Bay (Ebro Delta) jointly with three-dimensional numerical experiments in [...] Read more.

This article investigates water circulation in small-scale (~10 km²), shallow (less than 4 m) and micro-tidal estuaries. The research characterizes the hydrodynamic wind response in these domains using field data from Fangar Bay (Ebro Delta) jointly with three-dimensional numerical experiments in an idealized domain. During calm periods, field data in Fangar Bay show complex water circulation in the inner part of the estuary owing to its shallow depths and positive estuarine circulation in the mouth. Numerical experiments are conducted to investigate wind-induced water circulation due to laterally varying bathymetry. For intense up-bay wind conditions (wind intensities greater than 9 m·s⁻¹), an axially symmetric transverse structure occurs with outflow in the central channel axis and inflow in the lateral shallow areas. These numerical results explain the water circulation observed in Fangar Bay during strong wind episodes, highlighting the role of the bathymetry in a small-scale environment. During these episodes, the water column tends to homogenize rapidly in Fangar Bay, breaking the stratification and disrupting estuarine circulation, consistent with other observations in similar domains. Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

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13 pages, 30969 KiB

Open AccessArticle

Video Monitoring of Shoreline Positions in Hujeong Beach, Korea

by Yeon S. Chang, Jae-Youll Jin, Weon Mu Jeong, Chang Hwan Kim and Jong-Dae Do

Appl. Sci. 2019, 9(23), 4984; https://0-doi-org.brum.beds.ac.uk/10.3390/app9234984 - 20 Nov 2019

Cited by 11 | Viewed by 2664

Abstract

Shoreline processes observed by a video monitoring system were investigated under different wave conditions. A 30 m-high tower equipped with video cameras was constructed in Hujeong Beach, South Korea, where coastal erosion was suspected to occur. Two-year shoreline data since December 2016 showed [...] Read more.

Shoreline processes observed by a video monitoring system were investigated under different wave conditions. A 30 m-high tower equipped with video cameras was constructed in Hujeong Beach, South Korea, where coastal erosion was suspected to occur. Two-year shoreline data since December 2016 showed that beach area, Ab, has decreased, but periods of rapid increase in Ab were also observed. Shoreline change was closely related to the wave propagation directions and bottom topography. Ab increased when waves approached the shore obliquely, whereas it decreased when they approached in a normal direction. The shoreline became undulated when Ab increased, while it became flatter when Ab decreased. The undulation process was influenced by nearshore bedforms because the shoreline protruded in the lee area where underwater rocks or nearshore sandbars actively developed, with a sheltering effect on waves. Specifically, the locations of shoreline accretion corresponded to the locations where the sandbar horns (location where a crescentic sandbar protrudes toward the shore) developed, confirming the out-of-phase coupling between sandbars and shoreline. When waves with higher energy approached normal to the shore, the sheltering effect of sandbars and underwater rocks became weaker and offshore sediment transport occurred uniformly along the coast, resulting in flatter shorelines. Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

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15 pages, 1540 KiB

Open AccessArticle

Feasibility Study of Native Ureolytic Bacteria for Biocementation Towards Coastal Erosion Protection by MICP Method

by Md Al Imran, Shuya Kimura, Kazunori Nakashima, Niki Evelpidou and Satoru Kawasaki

Appl. Sci. 2019, 9(20), 4462; https://0-doi-org.brum.beds.ac.uk/10.3390/app9204462 - 21 Oct 2019

Cited by 36 | Viewed by 5193

Abstract

In recent years, traditional material for coastal erosion protection has become very expensive and not sustainable and eco-friendly for the long term. As an alternative countermeasure, this study focused on a sustainable biological ground improvement technique that can be utilized as an option [...] Read more.

In recent years, traditional material for coastal erosion protection has become very expensive and not sustainable and eco-friendly for the long term. As an alternative countermeasure, this study focused on a sustainable biological ground improvement technique that can be utilized as an option for improving the mechanical and geotechnical engineering properties of soil by the microbially induced carbonate precipitation (MICP) technique considering native ureolytic bacteria. To protect coastal erosion, an innovative and sustainable strategy was proposed in this study by means of combing geotube and the MICP method. For a successful sand solidification, the urease activity, environmental factors, urease distribution, and calcite precipitation trend, among others, have been investigated using the isolated native strains. Our results revealed that urease activity of the identified strains denoted as G1 (Micrococcus sp.), G2 (Pseudoalteromonas sp.), and G3 (Virgibacillus sp.) relied on environment-specific parameters and, additionally, urease was not discharged in the culture solution but would discharge in and/or on the bacterial cell, and the fluid of the cells showed urease activity. Moreover, we successfully obtained solidified sand bearing UCS (Unconfined Compressive Strength) up to 1.8 MPa. We also proposed a novel sustainable approach for field implementation in a combination of geotube and MICP for coastal erosion protection that is cheaper, energy-saving, eco-friendly, and sustainable for Mediterranean countries, as well as for bio-mediated soil improvement. Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

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24 pages, 3810 KiB

Open AccessArticle

Microbial Induced Carbonate Precipitation Using a Native Inland Bacterium for Beach Sand Stabilization in Nearshore Areas

by Pahala Ge Nishadi Nayanthara, Anjula Buddhika Nayomi Dassanayake, Kazunori Nakashima and Satoru Kawasaki

Appl. Sci. 2019, 9(15), 3201; https://0-doi-org.brum.beds.ac.uk/10.3390/app9153201 - 06 Aug 2019

Cited by 36 | Viewed by 4724

Abstract

Microbial Induced Carbonate Precipitation (MICP) via urea hydrolysis is an emerging sustainable technology that provides solutions for numerous environmental and engineering problems in a vast range of disciplines. Attention has now been given to the implementation of this technique to reinforce loose sand [...] Read more.

Microbial Induced Carbonate Precipitation (MICP) via urea hydrolysis is an emerging sustainable technology that provides solutions for numerous environmental and engineering problems in a vast range of disciplines. Attention has now been given to the implementation of this technique to reinforce loose sand bodies in-situ in nearshore areas and improve their resistance against erosion from wave action without interfering with its hydraulics. A current study has focused on isolating a local ureolytic bacterium and assessed its feasibility for MICP as a preliminary step towards stabilizing loose beach sand in Sri Lanka. The results indicated that a strain belonging to Sporosarcina sp. isolated from inland soil demonstrated a satisfactory level of enzymatic activity at 25 °C and moderately alkaline conditions, making it a suitable candidate for target application. Elementary scale sand solidification test results showed that treated sand achieved an approximate strength of 15 MPa as determined by needle penetration device after a period of 14 days under optimum conditions. Further, Scanning Electron Microscopy (SEM) imagery revealed that variables such as grain size distribution, bacteria population, reactant concentrations and presence of other cations like Mg²⁺ has serious implications on the size and morphology of precipitated crystals and thus the homogeneity of the strength improvement. Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

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13 pages, 778 KiB

Open AccessArticle

A Hybrid Approach Using Fuzzy AHP-TOPSIS Assessing Environmental Conflicts in the Titan Mining Industry along Central Coast Vietnam

by Manh Tien Dao, An Thinh Nguyen, The Kien Nguyen, Ha T.T. Pham, Dinh Tien Nguyen, Quoc Toan Tran, Huong Giang Dao, Duyen T. Nguyen, Huong T. Dang and Luc Hens

Appl. Sci. 2019, 9(14), 2930; https://0-doi-org.brum.beds.ac.uk/10.3390/app9142930 - 22 Jul 2019

Cited by 26 | Viewed by 4690

Abstract

Environmental conflict management gains significance in rational use of natural resources, ecosystem preservation and environmental planning for mineral mines. In Central Coast Vietnam, titan mines are subject to conflicting use and management decisions. The paper deals with an empirical research on applying a [...] Read more.

Environmental conflict management gains significance in rational use of natural resources, ecosystem preservation and environmental planning for mineral mines. In Central Coast Vietnam, titan mines are subject to conflicting use and management decisions. The paper deals with an empirical research on applying a combination of the fuzzy Analytic Hierarchy Process (AHP) and the fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) to measure environmental conflicts emerging as a result of titan mining in Vietnam. The methodology used in the paper combines the fuzzy AHP and the fuzzy TOPSIS to rank environmental conflicts and propose conflict prevention solutions in the titan mining industry of Ky Khang coastal commune (Ky Anh district, Central Coast Vietnam). Data was collected by using a questionnaire with 15 locals, 8 communal authorities, 2 district authorities, and 12 scientific experts on titan mining, environmental geology, and sustainability management. The result shows that, titan mining conflicts with the eight criteria of economic sectors at five alternative sites including beach, protected forest, agricultural area, settlement area, and industrial area. The conflicts between titan mining and forestry, agriculture, settlements, fishing and aquaculture are highly valued. The beach area shows most environmental conflict as a result of titan mining, followed by the agricultural area and settlement area. Based on the empirical findings, legal and procedural tools such as environmental impact assessments, strategic environmental assessments, integrated coastal zone management, marine spatial planning, and multi-planning integration advancing environmental management for titan mines in Vietnam are suggested. Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

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15 pages, 10345 KiB

Open AccessArticle

A Novel Remote Sensing Index for Extracting Impervious Surface Distribution from Landsat 8 OLI Imagery

by Hong Fang, Yuchun Wei and Qiuping Dai

Appl. Sci. 2019, 9(13), 2631; https://0-doi-org.brum.beds.ac.uk/10.3390/app9132631 - 28 Jun 2019

Cited by 10 | Viewed by 2840

Abstract

The area of urban impervious surfaces is one of the most important indicators for determining the level of urbanisation and the quality of the environment and is rapidly increasing with the acceleration of urbanisation in developing countries. This paper proposes a novel remote [...] Read more.

The area of urban impervious surfaces is one of the most important indicators for determining the level of urbanisation and the quality of the environment and is rapidly increasing with the acceleration of urbanisation in developing countries. This paper proposes a novel remote sensing index based on the coastal band and normalised difference vegetation index for extracting impervious surface distribution from Landsat 8 multispectral remote sensing imagery. The index was validated using three images covering urban areas of China and was compared with five other typical index methods for the extraction of impervious surface distribution, namely, the normalised difference built-up index, index-based built-up index, normalised difference impervious surface index, normalised difference impervious index, and combinational built-up index. The results showed that the novel index provided higher accuracy and effectively distinguished impervious surfaces from bare soil, and the average values of the recall, precision, and F1 score for the three images were 95%, 91%, and 93%, respectively. The novel index provides better applicability in the extraction of urban impervious surface distribution from Landsat 8 multispectral remote sensing imagery. Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

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20 pages, 20442 KiB

Open AccessArticle

Quantitative Assessment of the Environmental Impacts of Dredging and Dumping Activities at Sea

by Doan Quang Tri, Jaya Kandasamy and Nguyen Cao Don

Appl. Sci. 2019, 9(8), 1703; https://0-doi-org.brum.beds.ac.uk/10.3390/app9081703 - 25 Apr 2019

Cited by 6 | Viewed by 3830

Abstract

The dumping of dredge materials often raises concerns about the release of pollutants to the marine environment. Wind data from the Global Forecast System (GFS) model was used to simulate the wind-wave propagation from offshore in a two-dimensional (2D) model during September and [...] Read more.

The dumping of dredge materials often raises concerns about the release of pollutants to the marine environment. Wind data from the Global Forecast System (GFS) model was used to simulate the wind-wave propagation from offshore in a two-dimensional (2D) model during September and October 2016. The calibration and validation of the 2D model showed a high conformity in both the phases and amplitude between the observed and simulated data. The 2D mud transport simulation results of three scenarios showed that the concentration of suspended material in the third scenario tested (scenario 3) was greater than 0.004 kg/m³ in the low tide, spreading to a 9 km² area, and in the high tide, the concentration was 0.004 kg/m³ in a 6 km² area. Finally, the results of 2D particle tracking (PT) showed changes in the seabed due to the concentration of dredged material, and its dump (approximately 180 days) increased from 0.08 m to 0.16 m in 2.85 ha. In scenario 3, the element block moved quite far—approximately 2.9 km—from the dredge position. Therefore, the simulation results were qualified, as the dredging position situated far from the sea is significantly affected by the direction and velocity of wave-wind in the dredging position. Full article

(This article belongs to the Special Issue Coastal Deposits: Environmental Implications, Mathematical Modeling and Technological Development)

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