Shore & Beach最新文献

{"title":"Observations of wave attenuation, scour, and subsurface pore pressures acrossbthree marsh restoration sill structures on a sandy bed","authors":"J. Converse, M. Wengrove, P. Lomónaco","doi":"10.34237/1008832","DOIUrl":"https://doi.org/10.34237/1008832","url":null,"abstract":"With rising sea levels and more frequent exposure to extreme storms, coastlines worldwide are vulnerable to increased erosion and loss of natural marsh lands. In an effort to lessen these impacts, there is a growing practice of adapting hard or “gray” coastline protection techniques to more nature-based features that promote habitat and ecosystem health. Living shoreline marsh restorations utilize natural and naturebased materials to protect marsh shores from erosion while also allowing intertidal flushing to promote the health and diversity of the marsh. Our study investigates three types of living shoreline sill designs exposed to average and storm-energy wave conditions at varying water levels. The sills were designed to mimic constructed sills in practice (rock, oyster shell, tree root wads), but more generally vary in structure porosity and material dissipation potential. Large-scale laboratory experiments were conducted in the large wave flume at the O.H. Hinsdale Wave Research Laboratory. Wave transmission and reflection are used to demonstrate wave attenuation capability of each sill structure. Scour of the sill, bedload sediment transport rates on the seaward and shoreward sides of the sill, and sediment pore-water vertical hydraulic gradients were used to demonstrate the potential for sediment transport and liquefaction. Results will contribute to understanding the effect of sill material porosity and mass on structure stability, and the effectiveness of using green living shoreline sill structures in the continued effort to establish design criteria for living shoreline implementation.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116750502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Logistical and technical considerations for the use of unmanned aircraft systems in coastal habitat monitoring: A case study in high-resolution subaquatic vegetation assessment","authors":"","doi":"10.34237/1008825","DOIUrl":"https://doi.org/10.34237/1008825","url":null,"abstract":"In recent years, the technology and regulation surrounding the use of unmanned aircraft systems (UASs) has rapidly advanced. This has resulted in the availability of such technology for more common applications. Here we compare manned versus UAS platforms for acquiring high-resolution imagery of subaquatic habitat for the purpose of boat propeller scar delineation in seagrass meadows in Redfish Bay, Texas. We acquired aerial seagrass imagery in three 20-hectare plots using two UASs and one manned aircraft platform. The three plots represented a priori designations of low, moderate, and high seagrass scarring intensity. Overall, we observed that a smaller amount of scarring was detected in the manned aircraft imagery compared to that collected by the two UAS platforms, and that this disparity was much greater for the high scarring intensity plot. The observed differences in scar feature delineations were at least partially related to logistical difference between these two platforms — specifically, the lower altitude flown by the UASs results in a higher spatial resolution of the imagery that is less dependent on the camera specifications. From a logistical standpoint, the potential gain in spatial resolution via lower altitude flight could result in a reduced pricetag for high-resolution mapped products. Further, the rapid deployment and local operation typically resulting from the accessibility of UAS training greatly simplify the logistics of planning imagery acquisition at the appropriate scale. However, we realize that the current trade-off with regard to higher altitude is the ability to cover large areas with fewer transects and shorter flight time. Coverage limitations for UASs is currently rooted in both technological and legal issues. However, as technology and regulations evolve, the technical and logistical comparison of imagery products from UAS and manned platforms will become increasingly important to natural resource managers and researchers looking to make this transition to UAS.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115702000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coastal monitoring and data management for restoration in Louisiana","authors":"R. Raynie, S. Khalil, C. Villarrubia, E. Haywood","doi":"10.34237/10088111","DOIUrl":"https://doi.org/10.34237/10088111","url":null,"abstract":"The Coastal Protection and Restoration Authority (CPRA) of Louisiana was created after the devastating hurricanes of 2005 (Katrina and Rita) and is responsible for planning and implementing projects that will either reduce storm-induced losses (protection) or restore coastal ecosystems that have been lost or are in danger of being lost (restoration). The first task of the CPRA board was to develop Louisiana’s first Coastal Master Plan (CPRA 2007), which formally integrates and guides the protection and restoration of Louisiana’s coast. The System-Wide Assessment and Monitoring Program (SWAMP) was subsequently developed as a long-term monitoring program to ensure that a comprehensive network of coastal data collection activities is in place to support the planning, development, implementation, and adaptive management of the protection and restoration program and projects within coastal Louisiana. SWAMP includes both natural-system and human-system components and also incorporates the previously-developed Coastwide Reference Monitoring System (CRMS), the Barrier Island Comprehensive Monitoring (BICM) program, and fisheries data collected by the Louisiana Department of Wildlife and Fisheries (LDWF) in addition to other aspects of system dynamics, including offshore and inland water-body boundary conditions, water quality, risk status, and protection performance, which have historically not been the subject of CPRA-coordinated monitoring. This program further facilitates the integration of project-specific data needs into a larger, system-level design framework. Monitoring and operation of restoration and protection projects will be nested within a larger hydrologic basin-wide and coast-wide SWAMP framework and will allow informed decisions to be made with an understanding of system conditions and dynamics at multiple scales. This paper also provides an update on the implementation of various components of SWAMP in Coastal Louisiana, which began as a Barataria Basin pilot implementation program in 2015. During 2017, the second phase of SWAMP was initiated in the areas east of the Mississippi River. In 2019, development of SWAMP design was completed for the remaining basins in coastal Louisiana west of Bayou Lafourche (Figure 1). Data collection is important to inform decisions, however if the data are not properly managed or are not discoverable, they are of limited use. CPRA is committed to ensuring that information is organized and publicly available to help all coastal stakeholders make informed, science-based decisions. As a part of this effort, CPRA has re-engineered its data management system to include spatial viewers, tabular download web pages, and a library/document retrieval system along with a suite of public-facing web services providing programmatic access. This system is collectively called the Coastal Information Management System (CIMS). CPRA and U.S. Geological Survey (USGS) are also developing a proposal to create an interface for ","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117308101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In situ hydrodynamic and morphodynamic measurements during extreme storm events","authors":"S. Borrell","doi":"10.34237/1008743","DOIUrl":"https://doi.org/10.34237/1008743","url":null,"abstract":"Wave forcing from hurricanes, nor’easters, and energetic storms can cause erosion of the berm and beach face resulting in increased vulnerability of dunes and coastal infrastructure. LIDAR or other surveying techniques have quantified post-event morphology, but there is a lack of in situ hydrodynamic and morphodynamic measurements during extreme storm events. Two field studies were conducted in March 2018 and April 2019 at Bethany Beach, Delaware, where in situ hydrodynamic and morphodynamic measurements were made during a nor’easter (Nor’easter Riley) and an energetic storm (Easter Eve Storm). An array of sensors to measure water velocity, water depth, water elevation and bed elevation were mounted to scaffold pipes and deployed in a single cross-shore transect. Water velocity was measured using an electro-magnetic current meter while water and bed elevations were measured using an acoustic distance meter along with an algorithm to differentiate between the water and bed during swash processes. GPS profiles of the beach face were measured during every day-time low tide throughout the storm events. Both accretion and erosion were measured at different cross-shore positions and at different times during the storm events. Morphodynamic change along the back-beach was found to be related to berm erosion, suggesting an important morphologic feedback mechanism. Accumulated wave energy and wave energy flux per unit area between Nor’easter Riley and a recent mid-Atlantic hurricane (Hurricane Dorian) were calculated and compared.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121853122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The state of understanding of the effects of beach nourishment activities on coastal biogeochemical processes and conditions","authors":"Angelos Hannides, N. Elko, Kenneth K. Humiston","doi":"10.34237/1008734","DOIUrl":"https://doi.org/10.34237/1008734","url":null,"abstract":"Sandy beaches are sites of significant exchange of matter and energy between water and sediment. This rapid exchange is attributed to the high permeability of sandy deposits and is one of the key ingredients in understanding how a given beach will respond to a nourishment event as a habitat for many important organisms. The response is driven by fundamental abiotically and biotically mediated chemical reactions that are profoundly affected by the ability of chemicals to accumulate or to be flushed out of a sandy column in the beach substrate. So while attention has correctly been paid to the effects of nourishment projects on infaunal communities and the upper levels of the food web, the chemical reactions connecting physics and geology on the one hand and ecology on the other are treated as a black box. We synthesize existing findings on biogeochemical processes at source areas and renourished beaches before, during, and after nourishment activities, and identify gaps in knowledge. Among other processes, we highlight how the exposure of reduced sediment to an oxic water column can initially increase oxygen demand, fuel microbial primary productivity, and drive the mobilization of potentially harmful contaminants. Restoration of oxic conditions in surficial sands can proceed rapidly through rapid exchange between sand and the oxygenated water column under the influence of physical forces, such as waves and currents, and high sand permeability. Based on our findings, we recommend foci for research, outreach, and broader impacts in this field as well as discuss coastal management needs for policy makers, planners, contractors, and the public to encourage information sharing.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129674121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Myrtle Beach: A history of shore protection and beach restoration","authors":"T. Kana, H. L. Kaczkowski","doi":"10.34237/1008732","DOIUrl":"https://doi.org/10.34237/1008732","url":null,"abstract":"The City of Myrtle Beach (South Carolina, USA) initiated a three-phase plan for beach restoration in the 1980s: Phase 1 — small-scale beach scraping; Phase 2 — mediumscale nourishment by trucks using inland sand; and Phase 3 — large-scale nourishment by dredge using offshore sand. Phases 1 and 2 were locally funded and served as interim measures (1981-1996) until a 50-year federal project could be constructed (1997 to present). In the course of this work, the city pioneered several approaches to beach management and became a model for the state. These include: the prototype SC beach survey program; the profile volume method for determining shorelines in the presence of seawalls, which was codified in the Beach Management Act (BMA) of 1988; the first locally funded nourishment (1986-1987) and FEMA-funded postdisaster renourishment after Hurricane Hugo 1989-1990; and the first surveys of offshore deposits for nourishment. Before restoration, nearly 65% of the 9-mile (14.5 kilometer) oceanfront was armored with seawalls, bulkheads, and revetments (1981). After nourishment, erosion control structures are now buried and fronted by a vegetated storm berm, while a wider beach accommodates millions of visitors each year. Total volumes and adjusted costs of nourishment from 1986 to early 2018 are 4,997,201 cubic yards (3,820,360 m3) and ~$70.8 million ($2018), respectively. On a unit annual beach length basis, the cost of beach restoration and improvement has averaged $46.80 per one foot of shoreline per year (~$153.50/m/yr) ($2018). Oceanfront property values on a unit length of shoreline basis presently range from ~$15,000/ft (~$49,200/m) for single-family homes to ~$75,000/ft (~$250,000/m) for high-rise buildings, suggesting that beach maintenance has cost well under 0.5% of oceanfront property values per year. Sand loss rates have averaged ~0.8 cy/ft/yr (2.0 m3/m/yr), and the rate of nourishment has been more than adequate to keep up with the ~0.37 ft (0.11 m) sea level rise between 1980 and 2018.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114298476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Where coasts and rivers meet: Living on the edge requires us all to work together","authors":"S. Cunniff","doi":"10.34237/1008727","DOIUrl":"https://doi.org/10.34237/1008727","url":null,"abstract":"By recognizing the interconnected nature of our coastal and riparian systems — the physical, economic, and social systems — we can make progress toward creating and implementing better approaches to realize communities that are vibrant and increasingly resilient to higher sea levels and storm surges, inland flooding, erosion, and myriad other climate-related changes.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126726530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"California’s coastal development: Sea-level rise and extreme events — where do we go from here?","authors":"G. Griggs, Kiki Patsch","doi":"10.34237/1008722","DOIUrl":"https://doi.org/10.34237/1008722","url":null,"abstract":"As sea level continues to rise at an accelerated rate, California’s intensive coastal development and infrastructure is coming under an increasing threat. Whether lowelevation shoreline areas that are subject to flooding at extreme tides and times of storm wave run-up, or construction on eroding bluffs or cliffs, the risks will continue to increase from extreme events but, over the longer term, from continuing sea-level rise. Future sea-level rise values under different greenhouse gas scenarios have recently been projected and adopted by the state to be used in coastal land use planning and decision making. While beach nourishment can provide very short-term protection, and seawalls and revetments can provide somewhat longer-term protection, they both come with significant costs and also environmental impacts. The era of routine armor emplacement is coming to an end in California, and whether designated as relocation or managed retreat, now is the time to make the difficult decisions on how this will be accomplished and what the trigger points will be to initiate the response.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114301129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The fate of beach nourishment sand placed on the Florida East Coast","authors":"J. Houston","doi":"10.34237/1008721","DOIUrl":"https://doi.org/10.34237/1008721","url":null,"abstract":"Over 100 million yd3 of sand have been placed on Florida east coast beaches since the start of widespread beach nourishment in 1970. What has been the fate of this sand? Has it largely disappeared as some suggest, or is it largely in place, having increased beach width as much as expected? Shoreline position measurements show that beach nourishment has dominated shoreline change with beaches widening over 80 ft on average since 1970. Nourished beaches have widened an average of almost 120 ft and adjacent beaches that have never been nourished have widened almost 50 ft due to longshore transport moving nourishment sand to them. Using equilibrium profile theory, shoreline advance due to beach nourishment minus shoreline recession caused by longshore transport, inlets that trap sand in shoals, and sea level rise is shown to equal measured shoreline change within uncertainty limits in each east coast Florida county and for the entire coastline. About 90% of beach nourishment sand remains on profiles in the active littoral zone. Shoreline advance produced by beach nourishment has been eight times greater than the magnitude of the recession caused by sea level rise from 1970-2017. If beach nourishment sand is placed along this coast at the rate of the past 40 years, the shoreline will be wider in 2100 than in 2018 for all sea-levelrise scenarios of the Intergovernmental Panel on Climate Change (IPCC). Increased beach width since 1970 has produced significant benefits by reducing infrastructure storm damage and greatly increasing beach tourism.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121835808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beach and dune impacts due to Hurricane Florence in Dare County, North Carolina","authors":"E. Sciaudone, L. Velásquez-Montoya","doi":"10.34237/1008725","DOIUrl":"https://doi.org/10.34237/1008725","url":null,"abstract":"Less than two weeks after Hurricane Florence made landfall in North Carolina (NC), a team of researchers from NC State University traveled to Dare County to investigate the storm’s effects on beaches and dunes. Using available post-storm imagery and prior knowledge of vulnerabilities in the system, the team identified several locations to visit in the towns of Kitty Hawk, Nags Head, Rodanthe, Buxton, and Hatteras, as well as a number of locations within the Pea Island National Wildlife Refuge (Figure 1). Data collected included topographic profiles, still imagery and video from unmanned aerial systems, sediment samples, and geo-located photography. This Coastal Observations piece presents some of the data and photos collected; the full report is available online (Sciaudone et al. 2019), and data collected will be made available to interested researchers upon request.","PeriodicalId":153020,"journal":{"name":"Shore & Beach","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124451599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}