Impact Of Erosion Research Articles

Bank Erosion and Bankline Shifting of Dhansiri River In Golaghat District, Assam (1999-2019)

The Dhansiri River is the main river of the Golaghat District of Assam. However, unpredictable shifts of the river, serve erosion and frequent flooding have major adverse effect on the economy and ecology, affecting and threatening key villages, agricultural lands, school, and natural heritage sites. Erosion displaces a large number of the population often rendering them poor and landless. This study is aimed to investigate the flood erosion and bed aggradations scenarios of the Dhansiri River in the Golaghat district, Assam. Most of the villages in Golaghat district have been submerged by flood water and people and animal are taking shelter on the roadside and on the highlands. Golaghat in upper Assam has been most flood affected, where over 1, 19,179 people of 109 villages under Khumtai, Dergaon, Golaghat and Bokakhat revenue circle in Golaghat district have been affected by floods due to rise water of Brahmaputra and Dhansiri rivers. There are many problems being faced by this flood affected are due to river bank erosion: social, economic, health, education and political. The major impact of erosion is social, i.e., homelessness due to land erosion which compels people to migrate. After forced migration they suffer economic crisis, namely loss of occupation and loss of property.

Identifikasi Biota Asosiasi Pada Mangrove Jenis Avicennia spp. dan Sonneratia spp. di Pantai Laksamana Kabupaten Batu Bara

Mangroves are one of the most important natural ecosystems. Mangroves physically function as land protection areas against the impact of abrasion and erosion due to waves. In terms of chemistry, mangroves act as filters for pollutants, especially organic materials, and as an energy source that provides detritus, which is a food source for aquatic organisms. Aquatic biota that live in mangrove areas include mollusks, crabs, fish, oysters, and shrimp. In addition, the role of mangroves is very significant in maintaining the productivity of waters in coastal areas and supporting the lives of surrounding communities. The purpose of this study is to identify biota whose lives are associated with mangroves of Avicennia spp. and Sonneratia spp. The method used in this study is exploration. The location of the transect is made based on the purposive sampling method, where data is taken deliberately based on the abundance of biota and mangroves of the species Avicennia spp. and Sonneratia spp. The types of biota associations Nerita polita, Turritella attenuata, Chicoreus sp., Mytilus edulis, Geloina expansa, Scylla tranquebarica, Leptuca uruguayensis, Aratus pisonii, and Lepas balanoides. Mangroves associated with the above biota are from the types of Sonneratia alba and Avicennia marina.

Performance Assessment of Machine Learning Techniques for Gully Erosion Mapping in South-East Nigeria

Soil erosion is a serious environmental hazard affecting southeast Nigeria. The rate of erosion has continued to increase with devastating impact and has led to land degradation (gullies). To assess the socio-economic and environmental implications of gully erosion and to develop management plans to deal with them, quantitative and qualitative data on soil erosion rates at regional scales are needed. Hence, this study aimed at investigating the spatial and temporal variations of gully erosion impacted areas of South East Nigeria using machine learning techniques to develop a suitable approach for accurately modelling gully erosion impact in South East, Nigeria. Its objectives are to: acquire, process, and perform object-based gully mapping analysis with Kompsat-3 imagery of South East Nigeria, Nigeria using three machine learning algorithms (Linear discriminant analysis, Support Vector Machine, and Artificial Neural Network); compare the performance of the three selected machine learning algorithms using statistical techniques and determine the best suited for gully mapping within the study area; determine the pattern and trend of Gully Erosion in South East, Nigeria between 2010 and 2020, using the best-suited machine learning algorithm; and predict the future gully development pattern for the next 10 years. The methodology involved the acquisition and use of KOMPSAT-3 imagery, identification of gully erosion impacted areas, and topographic maps. Image preprocessing, development of classification scheme, object-based image analysis, trend analysis, and pattern of gully development and expansion. Accuracy assessment and gully development prediction to 2030 as data analysis. The results showed consistent identification of eight class features, including waterbody, dense vegetation, agricultural land, bare ground, built-up area, sand, savannah, and gully erosion. The performance evaluation of the three techniques revealed promising outcomes. LDA achieved an accuracy of 0.759, while SVM demonstrated a higher accuracy of 0.853 and balanced sensitivity and specificity. ANN showed good performance with an accuracy of 0.790. Based on its superior accuracy and balanced performance, SVM was selected for mapping the spatial trend of gully erosion in the study area.

Assessment of Riverbank Erosion and Accretion and its Impact on the People of Chairman Ghat, Noakhali, Bangladesh

Nestled within the vastness of the Meghna deltaic plain, Noakhali, and in particular, Chairman Ghat, stand as poignant examples of Bangladesh's intricate relationship with environmental challenges. The significance of the Meghna deltaic plain cannot be overstated, as it shapes the very fabric of the nation's landscape. However, this geographic richness comes hand-in-hand with vulnerability, and nowhere is this more apparent than in the relentless grip of riverbank erosion. Chairman Ghat, in Noakhali, epitomizes the struggle against this natural force, making it a focal point for understanding and addressing the profound impact of riverbank erosion in the region. The primary objective of this research work is to assessing river bank erosion & accretion and examine its the potential impact in the chairman Ghat area. In order to achieve this goal, this study employs remote sensing and GIS techniques to assess the erosion and accretion rates of Chairman Ghat on the Noakhali coast from 2000 to 2022 and conduct household survey to examine the socioeconomic impacts of river erosion on the local population. The findings revealed that Over the past 22 years, the Meghna estuary experienced a total of 667.0 km2 of erosion and 689.1 km2 of accretion. Chairman Ghat area alone witnessed a net erosion rate of 4.2 km2 per year during the specified period, resulting in a loss of 117.7 km2 of land, while only 25.3 km2 of new land was added. From household survey it is found that the adverse effects of riverbank erosion on the local community are evident, leading to the loss of vital agricultural lands, homesteads, and property damage that cannot be easily recovered. Consequently, a significant portion of the affected population is compelled to migrate, thereby exacerbating their socio-economic plight as they are forced to change professions. This research sheds light on the extent of riverbank erosion in Chairman Ghat, Noakhali, and elucidates its profound socioeconomic implications on the lives of the local inhabitants. The findings of the study will help to enhance our understanding of the specific impact of river erosion enabling the development of targeted strategies to protect vulnerable communities' lives, livelihoods, and environments. It will also promote cohesive coastal zone management, implementing robust measures that counteract the destructive consequences of riverbank erosion, thereby ensuring the sustainable development and resilience of these crucial ecosystems.

Assessing the Impact of Erosion and Farming Practices on the Spatial Distribution of Topsoil Characteristics in a Sloping Vineyard Using an Open-source QGIS Software

Erosion is one of the major threats that negatively affect agricultural soils. Several studies indicated that sloping vineyards are prone to soil erosion due to the soil management method. This study was conducted in a sloping vineyard planted in 2019 (with a slope of 100 and a slope length of 38 m) in Thu Cuc commune, Tan Son district, Phu Tho province, Vietnam. The main objective of the study is to evaluate soil characteristics (pH, particle-size distribution, organic matter, cation exchange capacity (CEC), N, P, and K macronutrients) related to terrain morphology, soil erosion, and farming practices. The open-source QGIS software was used to evaluate the spatial distribution of the soil characteristics. We found that the organic matter content, CEC, and clay content in the soils taken at the footslope zones were higher than those at the top of the hill as a result of soil erosion. In contrast, higher contents of K and silt were observed at the top of the hill compared to the footslope, indicating an unapparent impact of soil erosion on these two factors in the studied vineyard. Phosphorus was evenly distributed throughout the plot and influenced by the soil characteristics. Indeed, a strong correlation between total P content and soil pH, organic matter, and silt content was revealed in our study. On the other hand, cultivation practices exerted a significant impact on the prevailing accumulation of soil organic matter, CEC, total N, and clay particle size at the lower part of the vine rows following the horizontal flow. The vine rows were planted along the contour lines rather than the dominant slope of the vineyard can explain this tendency. In addition, no cover crops sown between the vine rows probably resulted in intense soil erosion at the steepest part of the terrain. Overall, the terrain morphology and farming practices played an essential role in the spatial distribution of soil characteristics. Therefore, integrating geographic information systems into building a digital database and predicting the spatial distribution of soil parameters is necessary to perform soil quality monitoring and serve sustainable land management.

Force-balance modelling of the impact of glacial erosion, trench sedimentation, megathrust weakening and glacial loading on the stress state of the crust at active continental margins

Force-balance analyses showed that the stress state at active continental margins is largely controlled by the gravitational force and the megathrust shear force and remains unchanged as long as subduction proceeds undisturbed. Glacially induced topographic changes and mass redistribution by glacial erosion, sediment transport and deposition may affect the force balance but the impact on the stress state and the style of deformation in the upper plate has not been investigated so far. Here, we use numerical force-balance models to investigate the stress changes in the upper plate resulting from (i) a reduction in mountain height in the arc by glacial erosion, (ii) a steepening of the arc front, (iii) a decrease in the megathrust shear force due to increased sediment subduction and fault weakening, (iv) an increase in sediment thickness in the trench, and (v) the load by an ice cap. Our model results show that each process causes distinct stress changes that affect different parts of the upper plate. The largest stress changes result from a reduction in mountain height, which increases compression in the arc interior, and fault weakening by increased sediment subduction, which decreases the megathrust shear force and hence deviatoric compression in the forearc and backarc. Smaller stress changes occur for a steepening of the arc front, increased sediment deposition in the trench and the load of the ice cap. The different stress changes may promote or suppress faulting in different parts of the upper plate. Application of our model to the North Patagonian Andes indicates that glacial erosion during late Cenozoic cold periods may explain the localization of deformation in the arc interior, whereas the reduced activity of thrust faults in the forearc and backarc may reflect a decrease in deviatoric compression caused by a decrease in the megathrust shear force.

Spatial assessment of soil erosion by water using RUSLE model, remote sensing and GIS: a case study of Mellegue Watershed, Algeria-Tunisia.

Soil erosion is an important global phenomenon that can cause many impacts, like morphometry and hydrology alteration, land degradation and landslides. Moreover, soil loss has a significant effect on agricultural production by removing the most valuable and productive top soil's profile, leading to a reduction in yields, which requires a high production budget. The detrimental impact of soil erosion has reached alarming levels due to the exacerbation of global warming and drought, particularly in the arid climates prevalent in Tunisia and Algeria and other regions of North Africa. The influence of these environmental factors has been especially evident in the catchment of Mellegue, where profound vegetation loss and drastic changes in land use and cover, including the expansion of urban areas and altered agricultural practices, have played a significant role in accelerating water-induced soil loss between 2002 and 2018. The ramifications of these developments on the fragile ecosystems of the region cannot be overlooked. Accordingly, this study aimed to compare soil losses between 2002 and 2018 in the catchment of Mellegue, which is a large cross-border basin commonly shared by Tunisian-Algerian countries. The assessment and mapping of soil erosion risk were carried out by employing the Revised Universal Soil Loss Equation (RUSLE). This widely recognised equation provided valuable insights into the potential for erosion. Additionally, changes in land use and land cover during the same period were thoroughly analysed to identify any factors that may have contributed to the observed risk. By integrating these various elements, a comprehensive understanding of soil erosion dynamics was achieved, facilitating informed decision-making for effective land management and conservation efforts. It requires diverse factors that are integrated into the erosion process, such as topography, soil erodibility, rainfall erosivity, anti-erosion cultivation practice and vegetation cover. The computation of the various equation factors was applied in a GIS environment, using ArcGIS desktop 10.4. The results show that the catchment has undergone significant soil water erosion where it exhibits the appearance of approximately 14,000 new areas vulnerable to erosion by water in 2018 compared to 2002. Average erosion risk has also increased from 1.58 t/ha/year in 2002 to 1.78 in 2018, leading to an increase in total estimated soil loss of 54,000 t/ha in 2018 compared to around 25,500 t/ha in 2002. Maps of erosion risk show that highly eroded areas are more frequent downstream of the basin. These maps can be helpful for decision-makers to make better sustainable management plans and for land use preservation.

Experimental Design and Protocol for Standardized Measurements of Rock Erodibility in Fluvial Impact Erosion

Experimental Design and Protocol for Standardized Measurements of Rock Erodibility in Fluvial Impact Erosion

Experimental investigation of impact force variations during high-speed liquid impingement erosion

High-speed liquid impingement erosion occurs in many industrial settings. The erosion transition, which occurs after the incubation period of liquid impingement erosion, significantly changes the erosion behavior, such as the material erosion rate and surface roughness; however, when and how the transition occurs remains elusive. The study focused on the impact force exerted on a material by a liquid jet impact during the transition in high-speed liquid impingement erosion. To this end, the force acting on an aluminum specimen attached to a force sensor during liquid impingement erosion was examined experimentally. The critical condition, which indicates the beginning of the accumulation stage of erosion, was detected through mass-loss measurements and visual observation of the target material. The results demonstrated a distinctive transition in the impact force with respect to the exposed flow volume. Additionally, a dynamic mode decomposition technique was employed to analyze variations in the impact force. Finally, the mechanism underlying the long-term variation in the impact force was discussed, and the correlation between the impact forces and erosion depths during high-speed liquid impingement erosion was presented.

Membrane fouling and influencing factors of a submerged commercial ceramic flat membrane bioreactor in treatment of coal chemical wastewater

An anoxic/oxic (A/O) treatment unit was upgraded using a submerged commercial ceramic flat-membrane bioreactor. The upgraded bioreactor effectively treated coal chemical wastewater. However, the factors influencing membrane fouling remain unclear. Thus, this study explored the mechanisms of membrane fouling of a commercial ceramic flat membrane bioreactor. With increasing duration of backwash, the rate of growth of transmembrane pressure (TMP) gradually increased. The proportions of concentration polarization resistance Rp and cake layer resistance Rf were 48.87% and 50.08%, respectively. Under the action of static electricity, negatively charged particles in the mixed liquid do not easily adhere to the membrane. Under conditions of high mixed liquid suspended solids (＞12 000 mg/L), an increase in the suspended solid content in the mixture caused membrane fouling and pore blockage. When the flux exceeded 58 L·m−2·h−1, the TMP increased sharply. When the aeration rate exceeded 200 mL/min, the impact of membrane erosion on fouling was no longer significant. The optimal suction/cessation ratio was 7:3. After cleaning with NaOH and NaClO, surface fouling of the membrane was significantly reduced.

Erosion impact on slurry pump behavior and productive life: An experimental and Numerical investigation

ABSTRACT Normally, the characteristics of the main parts of a slurry pump that may be suffer from erosion under two-phase flow circumstances have been extensively and thoroughly researched. Whereas, the effect of particle properties on pump behavior or performance has been the subject of several studies; however, the current research focused on various methods for reducing slurry erosion utilizing recent research methods. Thus, the analysis and investigation for various pressure distributions, velocity, erosion-rate, and vortex structure were carefully demonstrated in this study. In addition, the slurry pump’s wear or erosion characteristics were carefully examined, and it was found that as the flow rate increases, the wear of the suction surface worsens. As a result, the key findings of this research might offer the ideal guidance for optimum design and the right strategies for erosion protection for any slurry flow through centrifugal pumps.

Steady-state forms of channel profiles shaped by debris flow and fluvial processes

Abstract. Debris flows regularly traverse bedrock channels that dissect steep landscapes, but our understanding of bedrock erosion by debris flows and their impact on steepland morphology is still rudimentary. Quantitative models of steep bedrock channel networks are based on geomorphic transport laws designed to represent erosion by water-dominated flows. To quantify the impact of debris flow erosion on steep channel network form, it is first necessary to develop methods to estimate spatial variations in bulk debris flow properties (e.g., flow depth, velocity) throughout the channel network that can be integrated into landscape evolution models. Here, we propose and evaluate two methods to estimate spatial variations in bulk debris flow properties along the length of a channel profile. We incorporate both methods into a model designed to simulate the evolution of longitudinal channel profiles that evolve in response to debris flow and fluvial processes. To explore this model framework, we propose a general family of debris flow erosion laws where erosion rate is a function of debris flow depth and channel slope. Model results indicate that erosion by debris flows can explain the occurrence of a scaling break in the slope–area curve at low-drainage areas and that upper-network channel morphology may be useful for inferring catchment-averaged erosion rates in quasi-steady landscapes. Validating specific forms of a debris flow incision law, however, would require more detailed model–data comparisons in specific landscapes where input parameters and channel morphometry can be better constrained. Results improve our ability to interpret topographic signals within steep channel networks and identify observational targets critical for constraining a debris flow incision law.

Rehabilitative capacity of amendments to restore maize productivity following artificial topsoil erosion/ deposition

Anthropogenic activities leading to erosion-induced topsoil loss still present a pertinent threat to maize (Zea mays L.) productivity across the U.S. Corn Belt region. Using soil amendments has been proven effective in reversing the effects caused by erosion-induced topsoil loss and restoring agronomic productivity and yields to pre-eroded conditions. The current study investigated the impact of simulated erosion and repeated amendment application on agronomic productivity and yields over five growing seasons for a 23-year-old experiment at two central Ohio sites (Waterman Farm: WF; Western Station: WS). Simulated erosion/deposition was employed in 1997 to create three incremental topsoil depths (TSD) (20 cm topsoil removed (TSD-0); 0 cm topsoil removed (TSD-1); 20 cm topsoil added (TSD-2). Three soil amendments (inorganic, synthetic N fertilizer (INO); organic, compost manure (MAN); no amendment (CON)) were investigated for their ability to restore productivity in these cropping systems. Greater TSD produced higher germination counts and crop stand and yielded greater canopy cover during the initial five weeks after germination. The MAN amended soils observed higher values for the productivity parameters during the 2016–2020 growing seasons. Grain and biomass yields were 34–51% and 5–12% lower, respectively, for the TSD-0 level and 4–10% and 3–6% greater, respectively, for the TSD-2 level when compared to the undisturbed, TSD-1 level. Relative biomass yield losses (% per cm topsoil depth lost) were 0.921 for the WF site and 0.254 for the WS site, corresponding to average biomass losses (Mg ha−1 cm−1 yr−1) of 0.083 and 0.026 for each site. Relative grain yield losses (% per cm topsoil depth lost) were 1.29 for the WF site and 0.514 for the WS site, equating to mean grain losses (Mg ha−1 cm−1 yr−1) of 0.083 and 0.026 for each site. The rehabilitative capacity of the soil amendments followed a trend of INO > MAN at the WF site and MAN > INO > CON at the WS site. The deleterious effects of erosion on grain and biomass yields were found to be reversed with the addition of the INO and MAN amendments at the WS site due to improvements in soil health and SOC pools. The MAN amended soils produced grain and biomass yields that were nearly 2.5% and 5.6% greater than the INO amended soil when compared to the reference treatment (TSD-1-CON). This study demonstrates that sustainable soil management practices coupled with annual soil amendment addition can mitigate the deleterious effects of erosion and rebound maize yields to pre-eroded conditions for soils experiencing severe topsoil loss.

Healing Evaluation of Asphalt Mixtures with Polymer Capsules Containing Rejuvenator under Different Water Solutions

Polymer Ca-alginate capsules with rejuvenator bring a high healing level for asphalt concrete under dry healing environments; however, the healing levels of bituminous mixtures containing capsules under water healing conditions are still unknown. In view of this, this study aimed at exploring the healing levels of asphalt concrete containing polymer capsules under various solution healing conditions following cyclic loads. This study involved the preparation of capsules, followed by the evaluation of their morphological characteristics, resilience to compression, thermal endurance, and rejuvenator content. The assessment of the healing properties of asphalt concrete utilizing capsules was conducted through a fracture–heal–refracture examination. This study conducted Fourier transform infrared spectrum experiments to determine the rejuvenator release ratio of capsules under dry conditions and the remaining rejuvenator content in extracted bituminous binder from capsule–asphalt concrete after solution treatment. Meanwhile, a dynamic shear rheometer was utilized to investigate the rheological characteristics of asphalt binder. Results revealed that the healing ratios of capsule–asphalt concrete beams under a dry healing environment were significantly higher than that of beams under various solution healing conditions, and the alkali solution has the worst effect on the improvement in healing ratio. The coupled impact of moisture intrusion and ion erosion resulted in an enhancement of complex modulus of asphalt binder while concurrently reducing its phase angle. Consequently, the restorative capacity of the asphalt binder was weakened.

Erosion Model for Wind-Blown Sand Flow at Earthen Sites in Arid Environment, Northwest China

ABSTRACT This study investigates the erosive impact of wind-blown sand on earthen sites within arid environments through the establishment of meteorological observation equipment. Over a span of 47 months, a comprehensive approach encompassing numerical simulation, plume analysis, particle examination, three-dimensional scanning, and photo monitoring was employed to continuously monitor the patterns of wind-blown sand movement and the degradation of test walls. The study identifies six distinct zones extending from five times the windward side to ten times the leeward side of the test wall’s height. Notably, a negative correlation between captured particle mass and the height of the sand traps is observed, with 70% of particles concentrated within 50 cm from the base of the test wall. Three primary erosion mechanisms for wind-blown sand are elucidated, including frontal impact, side abrasion, and reverse sapping. Furthermore, the study highlights pronounced erosion at the base of the wall due to vortex flow, with depth erosion affecting the lower, side, and upper sections of the test walls. This paper delves into the erosion mechanisms and operational models of wind-blown sand flow surrounding discontinuous site walls, offering valuable insights for the conservation of ancient earthen sites.

Sea water exposure and erosion impact on multifunctional ABS-based thermoplastic hybrid composites

In the present work, acrylonitrile-butadiene-styrene (ABS)/glass fiber (varying fiber orientation angle) and with different % of carbon black (CB) particles-based hybrid composites are fabricated by hot press compression molding technique. Prepared composites were examined under marine conditions in sea water medium and erosion behavior under erodent particles entrained in gas fluid and found reduced impact. Morphological studies are studied through scanning electron microscope. Material removal mechanism is found to be micro-cracking at the impingement angle of 90°. Additionally, numerical analysis for the composite material with respect to single particle impact for erosion was conducted using LS-DYNA.

Geotechnical controls on erodibility in fluvial impact erosion

Abstract. Bedrock incision by rivers is commonly driven by the impacts of moving bedload particles. The speed of incision is modulated by rock properties, which is quantified within a parameter known as erodibility that scales the erosion rate to the erosive action of the flow. Although basic models for the geotechnical controls on rock erodibility have been suggested, large scatter and trends in the remaining relationships indicate that they are incompletely understood. Here, we conducted dedicated laboratory experiments measuring erodibility using erosion mills. In parallel, we measured uniaxial compressive strength, tensile strength, Young's modulus, bulk density, and the Poisson's ratio for the tested lithologies. We find that under the same flow conditions, erosion rates of samples from the same lithology can vary by a factor of up to 60. This indicates that rock properties that may vary over short distances within the same rock can exert a strong control on its erosional properties. The geotechnical properties of the tested lithologies are strongly cross-correlated, preventing a purely empirical determination of their controls on erodibility. The currently prevailing model predicts that erosion rates should scale linearly with Young's modulus and inversely with the square of the tensile strength. We extend this model using first-principle physical arguments, taking into account the geotechnical properties of the impactor. The extended model provides a better description of the data than the existing model. Yet, the fit is far from satisfactory. We suggest that the ratio of mineral grain size to the impactor diameter presents a strong control on erodibility that has not been quantified so far. We also discuss how our laboratory results upscale to real landscapes and long timescales. For both a revised stream power incision model and a sediment-flux-dependent incision model, we suggest that long-term erosion rates scale linearly with erodibility and that, within this theoretical framework, relative laboratory measurements of erodibility can be applied at the landscape scale.

Unveiling the Potential of Cavitation Erosion-Induced Heavy Crude Oil Upgrading

The application of ultrasonic waves in the processing of hydrocarbons is a new promising technology that has developed rapidly in recent years. However, the acoustic-induced cavitation erosion phenomenon is poorly studied. In this paper, a comparison study of cavitation erosion was carried out in water and oils with different viscosities produced from Ashal’cha and North Komsomol using an ultrasonic reactor operating at an industrial frequency of 20 kHz. The acoustic spectra obtained from hydrophones during the ultrasonic treatment of fluids can be characterized by using subharmonics of the main frequency and a continuous white noise level. Moreover, the cavitation erosion of aluminum foil under various ultrasound irradiation times and power levels was thoroughly investigated. It has been found that the process of ultrasonic cavitation has a less erosive impact on metal foil in oil due to its high viscosity. In addition, the formation of microflows in the oil phase, which also intensify the erosion process, is hindered. Cavitation erosion in the Ashal’cha oil sample exhibited a higher intensity compared to that in the North Komsomol oil sample. It was found that upon increasing ultrasound intensity in the case of the viscous (Ashal’cha) oil sample, cavitation stability was disrupted. In turn, this led to a reduction in the collapse energy of the cavitation bubbles. The results we obtained enable the assessment of cavitation erosion in crude oil and could be used to improve methodologies for monitoring and optimizing cavitation processes in crude oil.

Effectiveness of Dune Reconstruction and Beach Nourishment to Mitigate Coastal Erosion of the Ebro Delta (Spain)

Coastal areas facing increasing erosion are resorting to sand displacement strategies to mitigate the erosive impact, which is exacerbated by climate change. In the face of climate change, coastal managers are more frequently resorting to sand displacement strategies to recover eroding coastlines. These vulnerable coastal zones require innovative approaches to minimize the need for frequent sand replenishment, extend their effectiveness and lower their maintenance expenses. This study undertakes a comparison of four primary nourishment strategies—a conventional uniform nourishment technique and the placement of a single sand dune evaluated at three different positions—in contrast to a scenario where no intervention is carried out. The investigation employs the XBeach numerical model to assess the outcomes of these diverse strategies under both low- and high-energetic storm conditions. The case study is a degraded coastal beach in the Ebro Delta (Spain). The results reveal a significant decrease in erosion when the dune is positioned closest to the shoreline. However, this erosion mitigation effect diminishes as the dune is situated further inland. Conversely, the sand nourishment measure exhibits minimal fluctuations in the volume of eroded sand when compared to the scenario with no intervention.

Effects of coastal protection structures in controlling erosion and livelihoods

The fiscal and social cost of ameliorating the impact of coastal erosion resulting from climate change is an increasing burden for coastal states, and in developing nations the physical interventions implemented may present a double agony – increasing debt levels and potentially obstructing livelihoods in the rural coasts. Against this background, this study was conducted to explore the impact of hard-engineered coastal protection on coastal vulnerability and community livelihoods in Ghana using a combination of Unmanned Aerial Vehicles (UAV), geographic information system tools and social survey. Shoreline change analysis by the application of the Digital Shoreline Analysis System (DSAS) with aerial photographs from 2005 to 2022 reveals an average statistical rate of change of −1 m/year in shoreline erosion of the beaches. A computation of coastal vulnerability indices for fourteen beaches, incorporating coastal protection as an additional parameter shows that from east to west, hard-engineered coastal protection structures slowed the rate of erosion, whereas unprotected beaches have highly eroded, stressing the importance of coastal protection. In consequence, coastal protection has dire livelihood-reduction implications for coastal inhabitants who are predominantly artisanal fishers. A lack of acceptable consultation with the communities exacerbates the effects from these hard-engineering interventions. The beaches of high vulnerability concerns are Dzita, Ada, Sakumono, Glefe, Apam, Anlo, and Busua. To safeguard the livelihoods of vulnerable coastal communities, we support a shift from hard engineering to more integrated and nature-based coastal management approaches on a national scale since most parts of the coast are now susceptible to erosion in contrast to what was previously observed that only the eastern part of the coast was highly vulnerable.