List of Conchifera (Mollusca) identified during a beach nourishment in Matinhos, Paraná, Brazil

A global analysis of erosion of sandy beaches and sea-level rise: An application of DIVA

Coastal erosion is a worldwide problem; it is estimated that over 70% of the world’s beaches are currently experiencing erosion (Bird, 1985), and this number may approach 90% in the United States.1 Almost every conceivable form of shore protection has been attempted in the United States, including construction of seawalls, groins, and jetties as well as beach nourishment. The principal approach to protecting coastal property and maintaining recreational beaches inthe United States today is beach nourishment. Engineering structures such as groins and seawalls have often been shown to have detrimental effects on adjacent beaches. Also, their construction and maintenance costs are quite high. Therefore, coastal communities have come to rely on a “soft” engineering solution — beach nourishment — because it is environmentally sound, aesthetically pleasing, and, so far, economically feasible. However, global warming and accelerated sea level rise will cause more rapid rates of beach loss and could make even this alternative too costly for many resort areas along the U.S. shoreline. The cost to nourish all the major recreational oceanic beaches in the United States was estimated based on various sea level rise scenarios. The beach nourishment approach involves placing enough sand on the beach to maintain stable (nonretreating) conditions in response to rising sea level. The quantity of sand required to “hold the line” is evaluated under various sea level rise scenarios from the baseline scenario to the 1-m estimate ofthe Intergovernmental Panel on Climate Change. Beach nourishment is not a practical alternative for most Pacific island nations because sand is a scarce resource. In fact, beaches are often mined for sand for construction, contributing to beach erosion. For mainland countries, beach fill projects are more practical. Singapore was one of the that countries to use this technology in combination with building offshore breakwaters to form artificial headlands. As Western style sunbathing and the overall popularity of beaches for recreation continue to grow, beach nourishment can be expected to become a more common way to deal with sea level rise induced coastal erosion for highly developed beach resort areas.

Hurricanes this century have produced almost a trillion dollars in damages in the U.S., often to critical infrastructure that requires large costs and unacceptable times to repair or replace. There is a need for resilient protection of critical infrastructure where the protection must have the “ability to anticipate, absorb, adapt to, and/or rapidly recover from a potentially disruptive event” and be cost-effective. Coastal infrastructure can be protected by moving infrastructure back from the ocean (retreat), building protective structures, or by beach nourishment to effectively move the ocean back from the infrastructure. Retreat is very costly and highly unpopular on developed shores. Structures are expensive and lack resilience because their failure is usually catastrophic and repair slow. Beach nourishment is the favored protection option on developed shorelines because it significantly reduces infrastructure damage, provides resilient protection, and is cost effective with a high return on investment. The aftermath of Hurricane Sandy provided an example of the tremendous reduction of infrastructure damage due to beach nourishment. Dr. Stewart Farrell, director of the Coastal Research Center in New Jersey, reported: “It really, really works. Where there was a federal beach fill in place, there was no major damage — no homes destroyed. Where there was no beach nourishment, the destruction was complete. Older homes were ripped from foundations and tossed about.” A post-Sandy analysis showed that Corps of Engineers’ beach nourishment projects saved an estimated $1.3 billion in avoided damages. Beach nourishment provides resilient protection. It is partially self-healing, because during a storm some of the sand moves to offshore bars where it causes waves to break and reduces infrastructure damage, and then much of it returns to shore after the storm passes. It can be repaired relatively rapidly by use of a mobile dredge to replace net sand loss. It is a highly adaptable approach to climate change because its rate of sand placement can be varied to raise profiles to offset increased sea level rise. Beach nourishment pays for itself as nice, wide beaches sit in readiness to protect critical coastal infrastructure from storms, while in the meantime, tourists typically generate more than $100 in taxes annually to local, state, and the federal governments for every $1 these governments invest in beach nourishment.

Tourism based on “sun and beach” is the main economic activity in the Algarve region. A considerable part of the beaches of the Barlavento coast corresponds to embedded sand accumulated along the irregular lacework-like coastline of rocky cliffs cut into Miocene calcarenites. The pattern of touristic occupation in the Algarve and the geodynamics of the rocky sea cliffs, characterized by discontinuous and intermittent occurrence of slope mass movements, result in a high level of risk to beach users along pocket beaches. In order to mitigate the risk associated with the cliff geodynamics, artificial beach nourishment was performed in Castelo and Coelha pocket beaches on the Barlavento Coast, in 2014, increasing the beach area by 3.5 times. The effects of the beach nourishment on the occupation patterns of those beaches along the 2006-2016 decade, before and after the beach nourishment, are herein presented and discussed. Occupancy data were obtained covering different seasons along the year, by counting the number of beach users, regardless of age, using periodic and systematic photographs taken at strategic points that provide full coverage of the beach areas. Before the beach nourishments the area of dry sand outside high and moderate hazard zones, measured at half-tide under average summer wave conditions was 500 m2 at Coelha beach and 800 m2 at Castelo beach. After beach nourishment the same area increased to 6700 m2 at Coelha beach and 7100 m2 at Castelo beach. Results show that, following the beach fill, beach occupation by recreational users naturally shifted seaward, moving out from the cliff hazard areas. After the intervention, the occupation of high and moderate hazard areas reduced significantly, from 37 % to 11 % in Castelo beach and from 59 % to 27 % in Coelha beach. Keywords: beach nourishment; hazard; rocky cliffs; Algarve; Portugal.

Mobilisation of toxic trace elements under various beach nourishments

Artificial beach nourishment and beach recycling are widely used shoreline management techniques in the UK, especially in Sussex and east Kent where the majority of beaches are composed of mixed gravel and sand. Beach nourishment schemes in Sussex date back to the late nineteenth century; recycling was under way by 1900. Until the 1970s, beach nourishment in Sussex and east Kent was small-scale and occasional, but since this date there have been a proliferation of schemes, some very large-scale. Beach nourishment volumes peaked in 1995-1999; recycling in 1990-1994. To date, at least 6.7 million m3 of shingle and sand have been added to the beaches of Sussex and east Kent, and at least 7.6 million m3 of beach material recycled. The total investment in beach nourishment has a present day replacement value of about 134 million, while the recycling that has been undertaken can be valued at a further 10-11 million at present prices. The amounts of material added to the region's beaches indicate that South East England has undergone a 'sedimentary crisis'. The volume of fresh shingle derived from cliff erosion is currently insufficient to offset losses. The nourished beaches have performed well, but costs of beach nourishment have risen fivefold since the late 1980s, and it is unclear how long the technique will remain cost effective. If sea-levels rise as predicted due to global warming, beach nourishment will provide only a short-term 'fix'. In the medium to long term, as costs of beach nourishment rise to unacceptable levels, serious consideration will need to be given to abandoning some low-lying coastal areas.

Beach nourishment and sea level rise will dominate future shoreline changes on Florida’s 665 miles of sandy coast. Shoreline changes from 2020-2100 are projected along this entire coast using equilibrium profile theory that accurately predicted shoreline changes on Florida’s east coast from 1970-2017 (Houston 2019). Projections for 2020- 2100 are made assuming past rates of beach nourishment for the 30-yr period from 1988-2017 will continue and sea level will rise according to recent projections of the Intergovernmental Panel on Climate Change (IPCC) that include the latest knowledge on ice melting in Antarctica (IPCC 2019). Using the beach nourishment and sea level rise data, equilibrium profile theory is then used to predict shoreline change from 2020-2100 for each IPCC sea level rise projection. Beach nourishment is shown to produce shoreline advance seaward on average for all IPCC scenarios for both the entire Florida coast and east coast and for all scenarios except the upper confidence level of the worst scenario for the southwest and Panhandle coasts. Some of the 30 counties on these coasts will require a greater rate of nourishment than in the past to offset sea level rise for some or all of the scenarios, whereas some will offset sea level rise for all scenarios with lower nourishment rates than in the past. The annual beach nourishment volume for which a county has a shortfall or surplus in offsetting sea level rise for each IPCC scenario can be calculated with the information provided and examples are presented. The approach can be used on coasts outside Florida if beach nourishment and sea level rise are expected to dominate future shoreline change.

Florida is the world’s top travel destination and. if it were its own country, it would have more tourist visits than any other country. Its sandy beaches extend a shoreline length almost as great as the combined lengths of sandy beaches in California, Texas, and North Carolina. Florida’s beaches are easily America’s recreational playground. Every year, Florida beaches attract approximately 70% more day visits than combined attendance at national parks, college and professional sports, amusement parks, cruises, and NASCAR events. Beach tourism plays a huge role in Florida’s economy. Manufacturing and residential construction are major industries in Florida, but their revenues are each a fraction of beach-oriented tourist spending. Florida’s farmland, ranches, and forests cover 75% of its land area, but beach-oriented tourist spending is more than 10 times the total receipts of all Florida agriculture and forestry. Beach-oriented tourists generate $23.3 billion in tax revenues annually. These tax revenues are more than double the combined salaries of Florida K-12 public school teachers, law enforcement officers, and instructors at colleges and universities. Some Florida beaches have sand deficits because dams on rivers have blocked sand that normally would flow to the coast, and navigation projects have diverted sand out of the littoral system to ebb and flood shoals. Beach nourishment has then been needed to restore and maintain the beaches. Beaches widened by nourishment have not only been a magnet for tourists, but have also protected bil- lions of dollars of shore infrastructure from hurricanes. Beach nourishment has been a bargain, with beach-oriented tourists in Florida generating six times more tax revenues each year than have been spent on Florida beach nourishment during the 80 years from 1944-2023 (in 2022 dollars to account for inflation). Most Florida beach nourishment has been placed in the past 50 years, and beach-oriented tourists have generated $310 dollars in tax revenues and $1070 in Gross Domestic Product (GDP) annually for every $1 spent on beach nourishment. Miami Beach is a good example of the economic benefits of beach nourishment. It had almost no beach in the mid-1970s because of erosion, causing tourism to drop rapidly and itself to become a “seedy backwater of debt-ridden hotels.” Beach nourishment starting in 1978 caused a boom in tourism, and today Miami Beach has the most valuable property in Florida — worth more than the value of all Florida cropland. Miami Beach has had a return of $550 in tourist-generated taxes and $3900 in GDP for every $1 spent on beach nourishment.

On the Jinkoji coast facing the Pacific Ocean, beach nourishment using 8.7×104m3 of gravel with grain sizes ranging from 3 to 15 mm had been carried out by April 2008. After beach nourishment, a stable beach was formed between the artificial headlands. In response to the success in recovering a sandy beach, beach nourishment was also planned for the Komiyasaku coast south of the Jinkoji coast along with the Oritsu coast, which is a famous recreational beach. In this case, beach nourishment using gravel is considered to have been avoided for recreational use. Taking these conditions into account, beach nourishment using medium sand was planned. A stable beach topography produced by gravel nourishment was reproduced numerically using the BG model, while incorporating the effect of changing the grain size into the model, and the effectiveness of the model was confirmed. Then the model was applied to gravel nourishment along the Komiyasaku coast and to beach nourishment using medium sand at the Oritsu coast.

Lee County has the most complex shoreline among Florida’s 25 counties where beach nourishment has been placed. It has eight shoreline breaks such as passes (inlets) that have produced a very complex pattern of both significant shoreline recession and accretion since 1858. Beach nourishment would seem problematic on those shorelines that have experienced significant long-term recession. However, nourishment has been very successful, widening beaches an average of 132 ft from their first nourishments to 2018 along shorelines that had historically receded hundreds of feet. Tourism is the backbone of Lee County’s economy, supporting one of every five jobs. Beaches are the key to the county’s tourism, with more day visits annually than to the 12 most visited National Parks in America. Over 80% of Lee County tourists are beach tourists, and they had a 2019 economic impact in Lee County of $4.3 billion. Beach tourists generated $843 million in total taxes to federal, state, and local governments with these governments receiving $580, $160, and $40, respectively, in taxes for each $1 that they spent on beach nourishment. Moreover, Lee County received an economic impact of $690 for every $1 spent on beach nourishment. International beach tourists spent $462 million in Lee County in 2019, providing a gain in the U.S. international balance of payments. An investment in beach nourishment produces such compelling returns in taxes generated by beach tourists that the state and federal governments should reassess their priorities for this investment versus investments in inland flood control and navigation.

Yeon, Y.J. and Lee, J.L., 2021. Cost comparison between hard and soft approaches adapted as preventive methods of beach erosion. In: Lee, J.L.; Suh, K.-S.; Lee, B.; Shin, S., and Lee, J. (eds.), Crisis and Integrated Management for Coastal and Marine Safety. Journal of Coastal Research, Special Issue No. 114, pp. 519–523. Coconut Creek (Florida), ISSN 0749-0208. To protect the properties behind a beach, submerged breakwater, which is a representative hard approach, or beach nourishment, which is a representative soft approach, has been performed. The submerged breakwater protects the facilities behind the beach by controlling waves to mitigate erosion. This study estimates the cost required to secure a buffer section for the wave inflow of 30-year return period using submerged breakwater and beach nourishment methods for Sokcho Beach (Sokcho-si, Gangwon-do), one of the coastal maintenance project areas, and conducts economic assessment of the two methods. For the submerged breakwater method, the construction cost was calculated using the shoreline observation data, which were observed four times a year for about 8 years. For the beach nourishment method, the construction cost was calculated using the sand loss half-life (shoreline retreat over time) considering that the nourished sands cannot be maintained. The result showed that beach nourishment could obtain a higher economic feasibility. By enhancing sand maintenance, beach nourishment was evaluated as more economical than the hard approach when the sand loss rate (k), which determines the half-life of beach nourishment, was lower than 0.167 yr–1. Furthermore, beach nourishment is highly evaluated because it is an eco-friendly construction method, and it will be more effective when combined with other soft approaches.

The Dutch coast is one of the most heavily nourished coasts globally. An average of 12 mln. m3 is annually added to the coastline of only 432 km for dynamic coastline conservation. This study provides an overview of the operational aspects of the more than 300 nourishments for coastline maintenance that have been performed since the 1990s and discusses the evolution of the nourishment approach and lessons learned with regard to the nourishment design. The first nourishments were beach and dune nourishments to repair local beach and dune erosion. In the 1990s the nourishment efforts increased when nourishing the coastline was set in policy as the formal strategy to dynamically preserve the coastline. Simultaneously shoreface nourishments emerged, which aim to feed the coast gradually over a longer period than beach nourishments. In 2001 the volume of sand used for nourishments increased from 6.4 to 12 mln. m3 per year, to enable the coastal zone to stay in equilibrium with sea level rise. Channel wall nourishments were introduced around that time because they can slow down the landward migration of tidal channels and can accommodate large volumes of sediment. Nowadays, underwater nourishments are preferred because of the lower costs associated, but the decision for a beach, shoreface, or channel wall nourishment also depends on the morphology, the local setting, and the purpose of the nourishment. All nourishments combined have succeeded in conserving the coastline at its desired position over the past 30 years.

Beach nourishment has been widely used for beach protection around the world. However, there is limited information about beach nourishment in China. This study offers an overview of beach nourishment practices, status and technological advances in China, based on the literature, reports, and personal communications. The results demonstrate that beach nourishment has been recognized as an effective and environmentally friendly measure to combat coastal erosion and has been increasingly adopted in China, especially in the past decade. The unique characteristics of coastal China resulted in a difference in beach nourishment between China and Western developed countries in terms of the types, objectives, and shapes of beach nourishment. For the types of nourishments in China, there were approximately the same number of restored beaches and newly constructed beaches. For fill sediment, homogeneous fill and heterogeneous fill comprised 51.1% and 48.9% of projects, respectively. The objective of beach nourishment was mainly to promote coastal tourism, and the shape of nourished beaches was dominated by headland bays. This study also indicated that China has achieved a number of technological advances in beach nourishment, including methods of beach nourishment on severely eroded coasts and muddy coasts, an optimized design of drain pipes involved in urban beaches, and ecological design considerations. From the past decade of practices, four aspects were proposed as considerations for future nourishment: sand sources, technique advances, ecological effects, and management of beach nourishments.

Effects of beach nourishment on seawater intrusion in layered heterogeneous aquifers

In this study, to predict the effect of beach nourishment at Haeundae Beach, the waves and wave-induced currents were compared before and after beach nourishment using the XBEACH model. Representative wave conditions were determined for the data observed during 2014 (KHOA). Then, the Hs,max and Hs,1/10 values, and their prevalent directions, were used in the numerical modeling input data. A variable grid system was used for the <TEX>$5km{\times}2.5km$</TEX> model areas, and irregular waves based on the JONSWAP spectrum were given as incident wave conditions. In the summer season, eastward wave-induced currents were developed along the beach by the incident wave direction. Before the beach nourishment, the maximum speed around the surf zone was 1.2-1.5 m/s in the central zone of the beach, whereas the maximum speed increased to 1.4-1.6 m/s at the same areas when the currents toward Mipo Harbor were blocked as an effect of the groins after the beach nourishment. In the winter season, westward wave-induced currents were developed along the beach by the incident wave direction. After the beach nourishment, the maximum current speed increased slightly around the surf zone in the central area of the beach, and the littoral current speed decreased at the submerged breakwaters located at Dongbaek Island. As a result, after the beach nourishment, the maximum wave-induced currents increased about 10% in the surf zone of the central area of the beach.