Sustaining coastal ecosystems from the impact of rising sea levels is vital since they offer environmental services that are considered critical for humans’ well-being. The Coastal Vulnerability ...Index (CVI) is favoured in coastal hazard studies, as it provides a predictive approach to coastal changes through its simple numerical basis in classifying coastlines based on their potential to change. The recent widespread use of innovative technologies has contributed to accessible coastal components to investigate coastal hazards and analyse risk assessment. However, most of the studies related to CVI have rarely exploited these forms of technology despite being utilised in various geodetic applications. Hence, a comprehensive review is performed to evaluate the application of these technological advances, particularly on exploiting space geodetic technology to determine and classify coastal information from various analytical approaches. This paper systematised modern approaches utilizing space technology to form CVI to assess the significant processes affecting the vulnerability and evolution of coastal areas. It is envisaged that the exploitation of space technology will facilitate CVI development and promote effective coastal management strategies.
While there is agreement among tourism role-players on tourism's potential to contribute to socio-economic and environmental development, the industry is under severe threat from the increased impact ...of climate variability and change. This study examines the implications of rising sea level on coastal tourism in Cape Town, South Africa. Making use of mean sea level data from permanent sea level markers, remote sensing and field observations, supported by key informant interviews, the study found that coastal tourism is under threat from rising sea level. Current and projected rising sea level, as well as other extreme weather events such as the increased storm intensity trigger massive waves and tides that result in storm surges, which overtop and encroach into the land surface area. At least 80% of the city's 2019/2020 Blue Flag beaches are now under threat from rising sea level and coastal erosion. The study also found that some of the iconic tourist attractions such as the Cape Point, V&A Waterfront, Robben Island and several beaches along the False Bay area are under the same threat. Other tourism facilities under threat of weather extremes from climate change include servitudes, coastal roads, railway facilities and tidal pools: all threatening the attractiveness of some resorts.
Rising sea level is a huge challenge that requires innovative solutions for the city of Cape Town. Given the threat that the industry is facing, there is a need for a public-private partnership aimed at ensuring that there are sufficient resources to help the tourism sector is capable of adapting to climate change. Increase insurance cover is a must to protect businesses from anticipated increased damage from rising sea levels and associated weather extreme events. Continued risk assessment is a must to ensure the industry is abreast with the continued changes which are threats to coastal tourism resorts and infrastructure.
Category 4 Hurricane Harvey was an extraordinary rain-event. After landfall on the mid-Texas coast, the storm moved slowly to the east, dropping historic amounts of rainfall of more than 1.5 m over ...Southeastern Texas. A massive pulse of floodwater flowed down local canals and rivers, inundating coastal marshes on the McFaddin National Wildlife Refuge. The floodwaters left a muddy flood deposit over much of the marsh, averaging 2.8 cm in thickness along a north-south transect across the refuge. Hurricane Ike (2008) also left a sediment layer in marshes on the refuge, allowing a direct comparison of magnitude, pathways, distribution and character of the washover and flood deposits. Results suggest that Hurricane Harvey's flood sedimentation was the equivalent of seven years of “normal” sedimentation in the marsh. This is a significant contribution to marsh accretion, which counters elevation loss due to rising sea level. The pattern of flood sedimentation was weakly controlled by elevation, whereby lower elevations received more sediment, and more strongly controlled by proximity to flood sediment pathways, which included overbank flows from the Gulf Intracoastal Water Way and the delivery of sediment into the marsh via flows through interconnected lakes and ponds. In contrast, the magnitude of Hurricane Ike's washover sedimentation was controlled primarily by proximity to the Gulf shoreline. The study provides valuable new information on controls on the magnitude and distribution of flood sedimentation in coastal marshes and the role of terrestrial and marine sediment sources – a crucial and timely area of inquiry given the threat of submergence posed to coastal marshes by rising sea-levels.
•Hurricane Harvey deposited flood sedimentation in southeastern Texas coastal marshes.•Sediment magnitude controlled by elevation and proximity to sediment sources•Sedimentation magnitude was comparable to Hurricane Ike's washover sedimentation.•New information on marsh sediment sources, pathways, distribution and character•Terrestrial flooding can cause widespread aggradation of coastal marshes.
An ongoing field study of the effects of elevated atmospheric CO₂ on a brackish wetland on Chesapeake Bay, started in 1987, is unique as the longest continually running investigation of the effects ...of elevated CO₂ on an ecosystem. Since the beginning of the study, atmospheric CO₂ increased 18%, sea level rose 20 cm, and growing season temperature varied with approximately the same range as predicted for global warming in the 21st century. This review looks back at this study for clues about how the effects of rising sea level, temperature, and precipitation interact with high atmospheric CO₂ to alter the physiology of C3 and C4 photosynthetic species, carbon assimilation, evapotranspiration, plant and ecosystem nitrogen, and distribution of plant communities in this brackish wetland. Rising sea level caused a shift to higher elevations in the Scirpus olneyi C3 populations on the wetland, displacing the Spartina patens C4 populations. Elevated CO₂ stimulated carbon assimilation in the Scirpus C3 species measured by increased shoot and root density and biomass, net ecosystem production, dissolved organic and inorganic carbon, and methane production. But elevated CO₂ also decreased biomass of the grass, S. patens C4. The elevated CO₂ treatment reduced tissue nitrogen concentration in shoots, roots, and total canopy nitrogen, which was associated with reduced ecosystem respiration. Net ecosystem production was mediated by precipitation through soil salinity: high salinity reduced the CO₂ effect on net ecosystem production, which was zero in years of severe drought. The elevated CO₂ stimulation of shoot density in the Scirpus C3 species was sustained throughout the 28 years of the study. Results from this study suggest that rising CO₂ can add substantial amounts of carbon to ecosystems through stimulation of carbon assimilation, increased root exudates to supply nitrogen fixation, reduced dark respiration, and improved water and nitrogen use efficiency.
Brett, M.R., 2021. How important is coastal tourism for island nations? An assessment of African and Indian Ocean islands. Journal of Coastal Research, 37(3), 568–575. Coconut Creek (Florida), ISSN ...0749-0208. Coastal tourism is an important component of the global tourism industry, particularly for island nations where the tourism sector often exceeds 40% of gross domestic product. For African island and Indian Ocean island nations, the tourism sector's economic contribution has not received as much attention. This paper analyses the economic contribution of tourism to the economies of African island nations and analyzes tourism statistics from the World Travel and Tourism Council annual reports. Tourism is a major economic factor for the island nations and is concentrated in the coastal zone. The data indicates that islands with larger and more diversified economies performed better in terms of tourism receipts than did islands with less developed economies. The results show that the average per capita income on the islands is more than six-fold greater than the average for the African continent. To test the importance of the coastal zone, tourist infrastructure was mapped on two African island nations, Mauritius and the Seychelles. Given the predominance of tourist infrastructure in the coastal zone, and the importance of tourism to the economies of many of the African island nations, a rise in sea-level even of 0.5 to 1 meters poses a serious threat to the existence of these island nations.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The continuous sea level rising affects all those built heritage elements located near the seacoasts and oceans all over the world. Some of the most affected sites are the found Roman coastal fish ...tanks which were scattered along the coast of the Mediterranean Sea and had the purpose of breeding and keeping the fish in captivity. This study will analyze the current consequences of this phenomenon in these sites, mainly on those located in Spain. It will also analyze the effects in structures because of their submergence, the effects of erosion, the different reasons for coast line variations, the risks of sea storms and floods. Estimations are also made and they are based on the forecasts of sea-level rises in order of what it is being published in scientific fields. Finally, the pernicious effects that these types of infrastructures and their associated elements will suffer in a short or medium term will be studied.
We studied an excellently exposed section of the slightly metamorphic siliciclastic Amdeh Formation. The section is near the base of the Amdeh Member 4 (Am4). Am4 is of Early to Mid-Ordovician age ...and 1677 m thick. Two lensoid placers were examined for their mineral composition (X-ray diffraction, transmitted and reflected light microscopy), geochemistry (X-ray fluorescence), in-situ gamma-ray emissions and the sedimentary structures of the host rocks. The placers were deposited in a beach environment as indicated by sedimentary structures in the associated quartzites, such as parallel lamination, parting lineations and sand volcanoes and as indicated by the compositional and textural maturity of the host rock and the placers. Placer deposition may have been favored by rising sea-levels. Overall, the dark placers contain the following heavy minerals: anatase (up to 35–40%) > ilmenite > zircon > hematite (a few %) > and apatite (<1%, may be present in trace amounts as indicated by low phosphorous contents in XRF analysis). The presence of monazite is indicated in our study by LREEs plus yttrium. Due to the high amounts of ilmenite and anatase, the placers' titanium contents are high (up to 20.5 wt%). In both placers, the concentrations of the light rare earth elements (LREEs) lanthanum, cerium, praseodymium and neodymium plus yttrium (geochemically affine to HREEs) are noteworthy (between ∼3000 and 7000 ppm). The source rocks can be expected in metamorphic and acidic plutonic rocks in the basement of Oman, which may have shed detritus from exposed basin flanks, but other potential source areas lay to the north and south of the basin. A source area with pre-enriched quartz in sandstone to explain the massive quartz influx would also be possible. The coastal/shallow shelf facies of Am4 shows very little bathymetric variability despite its thickness, which requires rapid and continuous subsidence. We attribute basin subsidence to rifting, withdrawal (and subrosion?) of salt in the subsurface (Ara Formation) due to sediment loading and possibly to gravity-driven subsidence due to the presence of dense ophiolite units below the Ara Salt. The absence of the Amdeh Formation in the west (Jabal Akhdar Dome) may be explained by rift shoulder uplift. While the Amdeh Formation accumulated in the rift basin, the Jabal Akhdar region occupied parts of the northwestern rift shoulder.
•The lensoid placers formed in a beach environment during rising sea-level.•The placers contain anatase > ilmenite > zircon > hematite > apatite.•These minerals (and much quartz) may be derived from mature platform sandstones.•Anatase and ilmenite provide for the placers' high titanium contents.•The contents of Y and the LREEs La, Ce, Pr and Nd range from ∼3000–7000 ppm.
The coastal zone is a fascinating place that comprises the interface between sea and land. This interface, which is both very dynamic and sensitive, has been affected by strong urban and industrial ...pressures, and an increase in both traffic and recreational uses, leading to the deterioration of natural habitats and the growing instability of residential areas. Added to this disruption is ongoing climate change, which will lead to rising sea levels and increased wave action. Another problem we are increasingly concerned about is ocean pollution, which has been one of the main causes of threats to deep-water coral reef areas. The main sources of pollution include oil spills and offshore oil drilling. The effects of pollution caused by oil spills can not only seriously affect the global environmental balance of our planet but can also, on a different scale, seriously affect the economy of countries whose main resources depend heavily on the sea. Wave energy has the potential to alleviate the world's dependence on depleting fossil energy resources. With regard to coastal protection, the development of ecological solutions to preserve ecosystems and address coastal processes as an alternative to traditional coastal protection structures (seawalls, groins and breakwaters) is becoming increasingly important. These structures, generally referred to as passive measures, are usually built to alter the effects of sea waves, currents and the movement of sand along the coastline, with the aim of protecting beaches, ports and harbors. The concerns outlined are critically addressed throughout this review article. All of them are highly relevant today and, as demonstrated throughout this article, are expected to grow even more and with much more pronounced consequences starting from the middle of the current century.
This paper reviews the history of conceptual and numerical modelling of hard rock coasts (mean annual cliff erosion typically < 1 mm up to 1 cm) and its use in studying coastal evolution in the past ...and predicting the impact of the changing climate, and especially rising sea level, in the future. Most of the models developed during the last century were concerned with the development and morphology of shore-normal coastal profiles, lacking any sediment cover, in non-tidal environments. Some newer models now consider the plan shape of rock coasts, and models often incorporate elements, such as the tidally controlled expenditure of wave energy within the intertidal zone, beach morphodynamics, weathering, changes in relative sea level, and the role of wave refraction and sediment accumulation. Despite these advances, the lack of field data, combined with the inherent complexity of rock coasts and uncertainty over their age, continue to inhibit attempts to develop more reliable models and to verify their results.
Saltwater intrusion is a major hazard to coastal communities as it causes degradation of fresh water resources. The impact of rising sea level on the saltwater intrusion into coastal aquifers has ...been studied for decades, but how human activities affect the extent of saltwater intrusion is poorly understood. Human activities are known to influence groundwater availability indirectly by affecting precipitation patterns and directly by extracting groundwater and reducing recharge. In this paper the authors investigated the integrated impacts of human activities and rising sea level on aquifer recharge in Quintana Roo, Mexico, by incorporating anthropogenic impacts on groundwater recharge into an analytical saltwater intrusion model. The impact of human activities on groundwater extraction was firstly calculated; then, the resulting groundwater recharge was used in a Ghyben–Herzberg analytical model to determine the inland distance of saltwater intrusion. The analytical model tested six scenarios stemming from different combinations of human development patterns, hydrological settings, hydraulic conditions and rising sea level to obtain the range of possible inland movement of saltwater intrusion. Our results indicate that the groundwater recharge will decrease to 32.6 mm year
−1
if human activities increase by 50 % more. With 1-m sea level rise, inland saltwater intrusion distance is estimated to be up to 150 and 1 km under head-controlled and flux-controlled scenarios, respectively. A sensitivity analysis of the model reveals that the large hydraulic conductivity of the Quintana Roo aquifer (0.26–68.8 m s
−1
) is the most important factor in determining saltwater intrusion distance. Therefore, in this aquifer, the response to human activities is greatly exceeded by natural hydrogeological conditions.
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