Coastline Area Research Articles

Application of coastal hazard index to advance nature based protection for coastal communities in the small islands

In the face of rising the seas, relying solely on seawalls and other reinforced coastlines is unsustainable due to the high costs associated with their construction and upkeep and unforeseen effects on habitats. Restoring and conserving coastal habitats can be more affordable, long-term solutions for protecting the coast. Yet, basic knowledge about where, how, and for whom habitats decrease the risk of coastal disasters is typically lacking from decision-makers. This study investigates how climate change may affect coastal areas and how natural coastal habitats may help protect them. We studied two small tropical islands, Bintan and Seribu Islands, Indonesia. The research applied the InVEST Coastal Vulnerability model to calculate the hazard index. To assess the effect on the vulnerable population, a grid system for the coastal population was created and overlaid with the hazard index. The comprehensive analysis indicates that if the coastal habitat is lost in the future, Bintan and Seribu Islands will face a severe threat from rising sea levels, with 96% and 63% of the inhabitants being highly exposed to climate hazards. Furthermore, the model shows that preserving natural coastal habitats by 2040 could help protect approximately 104 and 17 km of coastline areas in Bintan and Seribu Islands, respectively. Ecosystems offer safeguards to certain thinly inhabited, distant coastal villages, certain of those with a large, vulnerable population. Thus, this study highlights that natural coastal habitat is essential in climate change adaptation. Enhancing and safeguarding these natural habitats is crucial for mitigating climate-related hazards and ensuring community resilience.

Climate stress testing for mortgage default probability

Extreme natural disasters, such as tropical cyclones, have a low probability of materialising, but a high social and economic impact, including spillover to financial institutions. We propose a framework for performing a climate-stress testing exercise for the default probability of mortgage loans. We estimated a dynamic credit scoring model based on survival analysis with a relative damage index built using the wind speed of tropical cyclones. We considered scenarios involving tropical cyclone wind speeds with different return periods. We analyse a portfolio of approximately 190,000 mortgage loans granted in Louisiana, one of the US states most affected by tropical cyclones. Our findings suggest that coastline areas are most exposed to severe damage from tropical cyclones. If the geographical area is exposed to an event with a very large return period of 1-in-1,000 years, the probability of default increases by approximately nine percentage points compared to a baseline scenario in the absence of tropical cyclones. However, this finding was mitigated by the insurance coverage. This percentage increases to almost 20 percent in the absence of insurance coverage.

Spatio-temporal pattern analysis of coastal zone in Nansha based on remote sensing technology

Among the most important and active areas of coastal cities is the coastal zone. Examining the changes in the coastal zone of Nansha District is helpful in identifying the spatiotemporal evolution pattern and driving force of this area, as well as serving as a guide for the preservation and exploitation of its resources. This is due to the fact that remote sensing's ability to collect and analyze coastlines can show minute variations in the way the water and land interact. The article uses drone orthophotos and Landsat and Quickbird paired with eight different sceneries from 1987 to 2021 to extract the coastline using remote sensing (RS) and geographic information system (GIS) techniques. The spatiotemporal features of the evolution of the Nansha shoreline are examined in order to guarantee correctness. and the motivating elements are talked about. The findings indicate that: 1) Over the previous 30 years, there has been a consistent upward tendency along Nansha District's shoreline. Among these, the percentage of artificial shoreline is growing annually, growing by about 56%, while the natural coastline is decreasing annually, decreasing by 70%. 2) There is a shift in the type of shoreline from natural to sea-reclamation, engineering construction, and aquaculture. 3) The modifications to the coastline have occurred in three phases: the first was the agricultural phase; the second was the port petrochemical phase; and the third was the reasonable restraint phase (quality construction). Wanqingsha, Longxue Island, and Nansha Bay's coastlines are all close to significant expansion areas of coastline. 4) The primary causes of the changes in the Nansha District shoreline are human activity, regional policy, and natural elements.

The Comparison of Indonesian and Singaporean Defence in Regional Security from Critical Analysis Perspective

Singapore and Indonesia's defence strategies are shaped by significant differences in terms of area and length of coastline. While Singapore's compact size makes it vulnerable to invasion, it also allows for the concentration of military resources within a smaller perimeter. A study was conducted to report a literature analysis that focused on analysis of Global Firepower that tracks military power information from 145 countries in the world. We identified and analyse the comparison of Singapore and Indonesia Military Strengths in 2024. The main purpose of this research is to identify and present relevant information without conducting experiments or direct observation.

Integrated GIS-based and water quality index for evaluation of groundwater quality in the coastal slum settlements of Lagos, Nigeria

This study aimed to identify drinking water suitability through a statistical and water quality index (WQI) approach in coastal slum settlements in Lagos, Nigeria. A total of 250 borehole groundwater samples collected for drinking purposes during the wet (125) and dry (125) seasons were analysed for their physical and chemical properties from 2019 to 2020. The physical and chemical characterisation of the region was conducted based on the correlation matrix, scree plot, PCA, Q-mode HCA, and ROC curve to identify the types of weathering, the influence of rock on precipitation and evaporation, and types of reactions that affect groundwater composition. The analytical mean concentration results revealed that SO4, Cl, TH, NO3, TDS, and PO4 surpassed the USEPA and WHO permissible limits in both seasons. The WQI results demonstrate that 7.6% and 6.7% of water samples fall into the excellent category, while 12.4% and 11.5% are moderately tolerable. In contrast, for both seasons, >100% of the samples fell into the unsuitable drinking category across SA1-SA5, SB1-SB5, SC1-SC5, SD1−SD5, and SE1−SE5. Groundwater quality mainly deteriorates due to anthropogenic activities and climatic variability. The spatial variation map indicates that groundwater quality is primarily affected during the wet season and, to a lesser extent, in a few slums during the dry season. Seawater influx in coastline areas has been identified as the main factor threatening the quality and availability of groundwater resources. As a result, the groundwater quality is mostly poor to unsuitable, and this study confirms its unsuitability for drinking. Hence, this study serves as a guide for effective action in sustainable groundwater management.

Investigating the socioeconomic impacts of sewage spillages on businesses in the Umhlanga Rocks coastline area.

The practical strategies revealed in this study contribute to reducing the vulnerability of communities and businesses to sewage spillages. Findings of the study have also been disseminated to the business owners and other relevant stakeholders to provide them with alternative solutions in 'softening the blow' caused by the spillages.

Valuing hybrid engineering approach: ecosystem and structural based DRR using InVEST model of coastal zone Sikka Flores-Literature Review

The effectiveness and long-term viability of implementing eco-DRR are heavily influenced by the regional context, including factors such as geographical locations, circumstances, and features of risks. The implementation of eco-DRR measures in coastal areas is effectively mitigating the hazards posed by high waves and other hydro-meteorological events, including storm surges, erosion, and coastal floods. The study was carried out within the framework of mangrove forest development as a means of combined protection and hard structural intervention. The success and efficacy of this endeavor rely on various circumstances, such as the magnitude of the large waves and the characteristics of the nearshore bathymetry, which dictate the extent to which the waves reach the coastline beach. In order to achieve optimal effectiveness and provide prompt safeguarding, it is necessary to employ a hybrid approach that combines ecosystem-based disaster risk reduction (DRR) methods with physical structures. This is because non-structural measures, such as ecosystems, inherently require time to grow and are highly susceptible to destruction from waves, rock debris, and water currents. Nevertheless, the ’hybrid approach’ or amalgamation must be formulated in a manner that does not engender novel or distinct dangers in various areas. This study seeks to conduct a comparative analysis of studies on Eco-DRR (Ecological Disaster Risk Reduction) focusing on high waves and other hydrometeorological risks in coastal areas. The objective is to develop a hybrid model that combines Eco-DRR and engineering effectiveness evaluation for disaster risk management, specifically for the Sikka Flores coastline area.

Connecting Land and Sea Vertical Datums: A Data Evaluation for Developing Australia’s AUSHYDROID Model

Land and sea vertical datums have traditionally been separate reference levels, due to the different methodologies and observations used in their derivations. However, the need for a seamless connection of these datums has become important due to a wide range of applications in the coastal zone. This study evaluates existing methods, oceanographic and geodetic models and observations for the development of an operational model of coastal heights called AUSHYDROID. We use a complex study area in north west Australia to gain a new insight into how accurately the separation between the lowest astronomical tide (LAT) and a reference ellipsoid can be estimated from existing models, which could form the basis of a national AUSHYDROID model for Australia. Our results are the first attempt to use this combination of existing data in this location, suggesting that ellipsoidal heights of LAT can be estimated to an accuracy of ∼0.2 m at the coast, with the combination of DTU18MSS and FES2014b having the lowest RMS of 0.125 m. However, in some complex coastline areas such as bays and estuaries, the differences increase to >0.5 m so that additional tide gauge observations with GNSS levelling connections and improved models are needed in these regions.

MOLLUSKS DIVERSITY IN THE PROTECTED COASTLINE OF BERBAK-SEMBILANG NATIONAL PARK INDONESIA

Mollusk has a role as a food source in benthic ecosystems. Presumably, there has been a decrease in its diversity on the protected coastline of Berbak-Sembilang National Park (BSNP) due to fluctuations in water quality parameters that threaten the sustainability of another biota in the web food system. The purpose of this study was to describe the diversity of mollusks and their correlation with water quality in the protected coastline area. The research methodology was carried out, namely: water quality data collection, mollusk sampling, diversity analysis, and correlation analysis. Principal component analysis and similarity analysis were used. The results showed that there were 28 species of mollusks, which were classified into two classes: Bivalvia (79%), and Gatropoda (49%), with 21 species. The mollusk abundance means 263.25 ind.m-2, and the diversity is categorized as low H'1 except stations 2 and 4. It is supported by the dominant species, namely Anadara granosa (36.61%), and Nutricola sp. (35.47%. There are two clusters of mollusks: open coastal areas are characterized by higher temperatures, nutrients, salinity, pH, currents, and brightness, and estuary clusters are characterized by higher dissolved oxygen and mollusk abundance.

A Study of Abrasion Identification for Coastal Areas at Sidangoli Gam Village

An abrasion of the coastal areas has occurred at Sidangoli Gam Village, West Halmahera of North Maluku. The original condition was planted mangroves for coastal areas protection. However, it has recently been abraded due to big waves from the Pacific Ocean. Local people and the government constructed a conventional dike using coral stone and wooden piles. Nonetheless, this dike construction is designed without physical meaning. On the other hand, local people cannot be moved to another location because they have fishermen, and this place is very familiar to them. This research aimed to study the identification factor of coastal abrasion area in the field, such as observation in length, abrasion in width, the measured elevation of land, taken coordinates by using GPS (Global Positioning System) for two points and measuring the slope of the land, lithology of the soil layer, land use, and also enquire about how long people have lived in the nearby coastline area. Therefore, the index of susceptibility to abrasion, called IKP, will be presented. The index of susceptibility of abrasion (CVI) results are obtained at 48,99, a moderate vulnerability condition. This value is considered as shoreline change of 4.0, visually observed of 5.0, abrasion in the length of 1.0, abrasion in width of 4.0, green belt width of 4.0, soil lithology of 4.0, land use of 4.0 and slope on land of 5.0. These results may be conducted using coastal dikes to avoid big and high waves from the Pacific Ocean.

Comparative Analysis on Shoreline Changes in Kelantan, Malaysia Using Digital Shoreline Analysis System (DSAS)

Kelantan is a Malaysian state renowned for its beautiful jungles and coastal districts. Kelantan, which is susceptible to monsoons and tidal waves, witnessed a tsunami-like inundation that affected its coastline landscape in 2014. This study does a comparative examination of shoreline alterations between 2013 and 2021 using the Digital Shoreline Analysis System (DSAS) technology. The coastline has grown by approximately 4.03 percent, from 62.1 kilometres to 64.6 kilometres, as a result of the implementation of digitalisation procedures. This highlights the increase in coastline areas between 2013 and 2021. Using GIS and satellite data, the study identifies considerable sedimentation in Pantai Geting and Lagun Jubakar, Tumpat, as well as severe erosion in Pantai Kundur and Pantai Cahaya Bulan, Kota Bharu. The analysis of the Shoreline Change Envelope (SCE) and Net Shoreline Movement (NSM) reveals an accretion rate of 728.44 m/year and a negative distance of -281.91 m/year, which indicates erosion. The paper concludes by emphasising Kelantan's shoreline expansion over the previous decade, stressing the significance of monitoring coastal changes for effective environmental management and catastrophe preparedness.

Modeling environmental sensitivity and risk assessment of PAHs in sediments along two marine coastal areas in Egypt

Modeling the environmental sensitivity index (ESI) is vital in the planning and management processes, especially along the coastal areas. The main objectives of the study were to define the main sources of polycyclic aromatic hydrocarbons (PAHs), establish an ESI model, and measure the risk of PAHs on humans and the environment using various equations. The methodology of the research involved analyzing PAHs according to the EPA 550 methodology in sediments of the coastline in two important coastline areas in Egypt, namely the Gulf of Suez and the Mediterranean Sea, modeling the sensitivity of PAHs using ArcGIS 10.5 by integrating different physical, biological, and land use/cover factors, identifying the sources, and performing a risk assessment. Nine sediment samples were collected from each area. The produced sensitivity map could explain the highly sensitive areas along the Mediterranean Sea and Gulf of Suez coastlines (especially areas that were near drains' outlets, industrial sites, and sea ports). The highest mean PAH concentrations were Acenaphthylene and Fluorine in the Mediterranean Sea and Suez Gulf, respectively. It's obvious that the individual PAH concentrations were within the ERL, ERM, and PEL threshold limits, indicating no adverse biological impacts. The ratios of BaA/BaA + Chy, Flu/Flu + Py, and Ant/Ant + Phe gave an indication that most PAH sources were petrogenic (63.64%) and others (36.36%) were from petroleum combustion. The principle component analysis (PCA) indicated a diverse correlation among the isomer ratios and LU/LC activities. The carcinogenic risk values were in the very low category (<10−6) for both children and adults. The most significant contributors to carcinogenicity were IP and BkFlu in the Mediterranean Sea and Suez Gulf, respectively. Increasing sources of carbon in seawater, especially with climatic change, may impact the aquatic environment and have impacts on organisms and coral reefs. So it is highly recommended to keep shorelines and seawater free of oil spillage activities along the coastal areas or take actions towards this.

Study on the Impact of the Coastline Changes on Hydrodynamics in Xiangshan Bay

Coastline changes have significant impacts on coastal hydrodynamics. Xiangshan Bay is a semi-closed and long-narrow bay located in Zhejiang Province, China. Its coastline has changed dramatically in recent decades; however, the variations in the small-scale hydrodynamics in the changed coastline areas have not been carefully studied. This study uses the Finite-Volume Community Ocean Model (FVCOM) to design a set of control experiments and five sets of compared experiments targeting the areas with significant coastline changes in Xiangshan Bay over the past 21 years. It was found that the coastline changes at the mouth of the bay, such as areas near Meishan Island and Dasong, have a significant impact on both residual currents and tidal currents, changing the amplitudes and phase distributions of the tides. Coastline changes in the inner bay have lesser impacts on hydrodynamics, mainly affecting the small-scale areas in the vicinity.

Potential of Red, Brown, and Green Macroalgae from Dato Beach, Majene, Indonesia as Natural Food Preservative

Macroalgae is one of the natural resources present in Indonesian coastline areas – specifically in Dato Beach, Majene, South Sulawesi. The abundance of macroalgae found in Dato Beach can be utilized in various sectors – including health, cosmetics, and food. The aim of this study was to investigate the secondary metabolites of three types of macroalgae in Dato Beach and their potential to inhibit the growth of pathogenic bacteria in food. The three macroalgae utilized in this study were Turbinaria decurrens (brown algae), Galaxaura rugosa (red algae), and Halimeda opuntia (green algae) representing the three groups of macroalgae based on their dominant pigments. Four types of pathogenic bacteria – namely, Staphyloccus aureus and Bacillus cereus as Gram-positive bacteria plus Salmonella typhi and Escherichia coli as Gram-negative bacteria – were collected from the Biology Laboratory at Universitas Sulawesi Barat, as these bacteria are commonly responsible for food spoilage. The study began with a sampling of macroalgae, followed by cleaning and drying, and subsequently extraction using methanol as the solvent. Methanol was chosen as the universal solvent for its ability to extract both polar and nonpolar components. Phytochemical screening was carried out to test for the presence of flavonoids, steroids/terpenoids, and alkaloids, which represent the three groups of secondary metabolites. The antimicrobial test was carried out using the well diffusion method, as a control used 80 ppm of ampicillin. The results of the study indicated that T. decurrens contains flavonoids, steroids, and alkaloids, G. rugosa contains flavonoids, terpenoids, and alkaloids, whereas H. opuntia only contains terpenoids and alkaloids. Furthermore, G. rugosa was found to have the best ability to inhibit bacteria, with an inhibition zone ranging from 22–23 mm; in some treatments, the diameter of the inhibition zone was even larger than the positive control. T. decurrens was only effective in inhibiting the growth of S. aureus, whereas H. opuntia demonstrated the potential to inhibit the growth of S. aureus and E. coli, and for B. cereus and S. typhi, it could only be inhibited by 100% (1000 μL) extract of the H. opuntia extract.

Assessment of Marine Coastal Water Pollution from Karachi Harbour Pakistan

In Pakistan, marine pollution is a major problem that is caused by the waste from industrial, municipal, agronomy, and oil leak sources. The pollutant loads along with the coastline areas near Karachi is received from terrestrial contaminants including discharges from Karachi Harbour located on the estuary of the Lyari river. Karachi generates 472 Million Gallon per Day (MGD) of wastewater out of which only 55 MGD is treated and the rest is discharged in the sea. The prevailing sewage treatment plants are functioning at reduced capacity due to the insufficient transmission capacity of interceptors. Water sampling was carried out from the Lyari River and five different selected coastal point around Karachi harbour for physicochemical parameters and selected heavy metals. Results show that the Karachi Harbour area is noticeably polluted, whereas; the coastal environment in the vicinity of Karachi is also under the stress of pollution. High COD and BOD5 values were noticed at the Lyari river samples and the sampling locations close to the Lyari river outfall area. The Pb, Cd, Ni, and Hg heavy metals that pollute marine water are found. This situation is due to the discharge of mixed effluents of industrial and domestic wastes as well as dredging, cargo handling, dumping of ship waste and other coastal activities. The highest value of pollution observed at Karachi Harbour which is near Lyari river mouth, where the domestic and industrial effluents with organic and inorganic wastes have a greater influence on the water quality and the marine environment. At present, there is no effective controlling mechanism for industries to treat their waste, nor has any investigation to assess increasing marine pollution been carried out. As a result, there is an adverse impact on fish habitat and mangroves, corrosion of cargo ships, naval vessels and the residents living in the coastal area. Therefore, the government agencies and industrial sectors should work together to avert marine pollution and attain total environmental sustainability.

Environmental risk assessment for fecal contamination sources in urban and peri-urban estuaries, in Escambia and Santa Rosa counties, FL, USA.

Fecal pollution of estuaries and adjacent creeks and streams is of significant concern along the Gulf of Mexico. The prospective threat to human life and water quality impairment via fecal pollution is a substantial danger to the strength and resistance of coastline areas. Pensacola, FL, has a prosperous coastal tourism industry that is utilized for numerous other uses, such as recreational watersports and boating, seafood, and shellfish harvesting. However, the frequency and severity of fecal contamination present possible socio-economic issues, specifically financial hardships. Therefore, understanding the source, abundance, and fate of fecal microbial pollutants in aquatic systems signifies an imperative initial stage for detecting the host sources and techniques to lessen their transport from the landscape. This research aimed to quantify the fecal indicator bacteria (FIB), Escherichia coli, and perform microbiological fecal source tracking to verify if the fecal inputs are of either animal or human host origin. Surface water samples were taken from urban and peri-urban creeks for two sampling periods (February 2021 and January 2022), and IDEXX Colilert-18 (USEPA Standard Method 9223) was used for E. coli enumeration. DNA extractions were obtained from each sample, and quantitative PCR was utilized for fecal microbial source tracking (MST) to detect human, dog, ruminant, and bird host-specific Bacteroides DNA. The result indicates elevated quantities of FIB, E. coli, that surpass the threshold considered safe regarding human health. E. coli at six sites over the two sampling periods exceeded the impairment threshold, reaching as high as 866.4 MPN/100ml. Fecal source tracking identified human host fecal contamination at four of nine sites, dogs at three of nine, and birds at one site. However, those sites with sources identified via MST all had E. coli levels below impairment thresholds. No sites were determined to be positive for ruminant as a source or for the pathogen Helicobacter pylori. No canine host fecal inputs were found in January 2022, and only one site with human sewage. Our results highlight the utility of MST in assessing bacterial inputs to water bodies and the challenges.

Evaluation of tsunami inundation in the plain of Martil (north Morocco): Comparison of four inundation estimation methods

The Alboran Basin may be subject to tsunami hazards. If such an event were to occur, it is expected that the urbanised and densely populated areas of northern Moroccan coastline would be affected. Precise inundation hazard maps are needed for tsunami risk management in this region. In this article, we argue that the diversity of hazard mapping methods ensures the robustness of the scientific knowledge about the exposure of a territory. Hence, the main objective of this study is to analyse the exposure of the plain of Martil (north of Morocco), by using four hazard mapping methods to create inundation maps for two scenarios of tsunamis generated by extreme submarine mass failure (SMF) in the Alboran Sea, of 0.9 ​km3 and 3.8 ​km3 respectively. A digital terrain model of the plain was used to explore four methods of inundation mapping. The static method identified 4.32 ​km2 and 19.83 ​km2 of flooded areas for each scenario using water height values as inundation thresholds. The hybrid and the volumetric methods use the volume of water to determine the inundation extent. For the first scenario, 3.51 ​km2 of the plain were inundated using the hybrid method, and 20.11 ​km2 for the second scenario. The results of the volumetric methods are 2.32 ​km2 and 7.82 ​km2 respectively for the first and second scenario. Finally, the fourth method relies on numerical hydrodynamic modelling of tsunami inundation (Freshkiss3d® code). With this method, 4.55 ​km2 of the plain were flooded in the first scenario, and 24.12 ​km2 for the second. The comparison of the results highlights that the most sensitive areas to tsunami inundation are the lowest topographic ones, being the beaches and the wadis floodplains. This result raises questions on the current coastal development and the preparedness of its population, thus calling for more attention to engage on tsunami risk management related questions.

A High Precision Tidal Model Based on Multisource Tidal Harmonic Constants for Offshore China

As the accuracy of analytical instruments improve, the accuracy of ocean tide load displacement (OTLD) in geodesy and ocean dynamics is becoming increasingly demanding. The method of integrating through the load Green’s function using the ocean tide model is the main means of OTLD correction. However, although different tidal models have high accuracy in open ocean regions, they are less precise and less practical in the offshore areas of China, making it difficult to correct OTLDs accurately in complicated coastline areas of China. In this work, we evaluate the accuracy of 13 different tidal models in offshore China, and construct a new tidal model, new.chinasea.2022, based on the combination of high-precision tidal harmonic parameters. The OTLD correction efficiency of new.chinasea.2022 and conventional tidal models was assessed by wRMS analysis of GPS coordinate time series from the Crustal Movement Observation Network of China (CMONOC). It turns out that (1) the newly released tidal model performs better than the old model in offshore China, and there are differences in the performance of different models for each tidal constituent in different seas; (2) The OTLD correction of new.chinasea.2022 performed better in the offshore region of China, improving the correction of FES2004 by 1%-12% and osu.chinasea.2010 by 1%-6.5%.

Paleoenvironments and stratigraphy of the Valanginian–Hauterivian carbonates of the Arabian Platform: Implications for the recognition of the Weissert Event on the Southern Tethys

On the Arabian Platform, the Valanginian Weissert Event is associated with the sudden drowning of a major north-easterly prograding carbonate platform located on the southern margin of the Tethys Ocean. This was associated with a sharp back-stepping of the main facies belts to the south-west, bringing shallow marine carbonates into the previously restricted platform top. Integrated detailed facies analysis, biostratigraphy (including nannofossil and palynology) and carbon isotopes have been used to reconstruct the evolution of the carbonate shelf during the Valanginian–Hauterivian in Saudi Arabia. During the early Valanginian the study area was dominated by the deposition of dolomitized clay-prone microbial intertidal mudstones, which passed basinwards into low-energy inner ramp limestones. These facies encompass the initial stage of a 3rd order transgressive trend above the regional Lower Valanginian Unconformity. They are sharply overlain by Lithocodium/Bacinella-dominated floatstones, indicating the maximum flooding of the platform during the late Valanginian. These deposits systematically increase in thickness and abundance towards the platform margin and are associated with a broad positive excursion in δ13C (c.+2‰ V-PDB), corresponding to the Weissert Event. The presence of abundant Lithocodium/Bacinella in strata deposited during the major flooding of the platform is consistent with higher nutrient levels and increased upwelling during the late Valanginian. The Valanginian–Hauterivian boundary is marked by a regional unconformity identified through palynology and benthic foraminifera assemblages, and locally confirmed by carbon isotopes. The combination of carbon isotope data with detailed palynology and micropaleontology provided a stratigraphic resolution in line with ammonite biozones published in the western Tethys. The Valanginian–Hauterivian continental palynoflora, described for the first time on the Arabian Platform, is dominated by primitive conifer pollen such as Classopollis suggesting a rather arid climate in agreement with published reconstructions. In addition, the occurrence of various fern and bryophyte spores suggests an increase in humidity along coastline areas, associated with higher continental input into inner ramp settings, therefore affecting the carbonate factory.

Rockfall susceptibility analysis through 3D simulations in marine protected areas of the Portofino coastline: case studies of San Fruttuoso and Paraggi bays

The research focuses on the assessment of the potential geomorphological hazards affecting the stability of the Promontory of Portofino (Regional Natural Park of Portofino, Northern Italy), mainly on the bays of San Fruttuoso and Paraggi. The study area constitutes one of the most representative and most populated environments, both by locals and tourists, of the entire Liguria area. For this reason, there is a growing need for investigation on the natural dynamics of these landscapes, based on detailed topographic information. The research starts from a regional geological and geomorphological analysis specific to the study area, combined with a multi-model comparison algorithm (M3C2), which allows comparing two LiDAR datasets acquired in 2008 and 2020, respectively, to assess the overall dynamics of the promontory development. Then, a detailed study of San Fruttuoso and Paraggi bays, two key points for visitors and therefore for management, is performed. Three-dimensional modeling of rockfalls is carried out, which allows the development of a specific management oriented to the use of nature-based solutions (NBSs) strategies, respecting the environment and increasing safety against instability processes in these areas.