DOCSLIB.ORG

Impacts of Jetty Construction on the Wave Heights Off the Kiashahr Lagoon S

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Impacts of Jetty Construction on the Wave Heights Off the Kiashahr Lagoon S Impacts of jetty construction on the wave heights off the Kiashahr lagoon S. A. Azarmsa,1∗ M. Esmaeili,2 and A. Karami Khaniki3 1Faculty of Marine Sciences, Tarbiat Modares University, Gisha, Tehran, Iran 2Faculty of Marine Sciences, Chabahar Maritime University, Chabahar, Iran 3Soil Conservation and Watershed Management Research Center, Tehran, Iran ∗Corresponding author: [email protected] Coastal managers and ecologists are confronted with tasks to estimate wave heights in the Kiashahr sea area, since hydrodynamic factors can profoundly impact this environment. In this study, wind data and an empirical wind wave predicting model were used to estimate deepwater wave characteristics in the Kiashahr sea area; while a numerical model was used to determine wave characteristics in shallow waters. Wave heights were also determined and compared at different stations before and after construction of 2 jetties at the lagoon mouth to evaluate their efficiency in wave height reduction. Results revealed that wave height is in the range of 0.8 to 1.2 m at Sefid Rud river mouth. Significant wave height reduction in the range of 0.15 to 1.2 m occurred at the entrance of the lagoon due to construction of the jetties. This attenuation of wave energy may result in some impacts on the ecosystem health of Kiashahr lagoon such as increased sedimentation, reduction in flushing rates, dumping of garbage and consequently, more pollution. Keywords: wind, Caspian Sea, Iran Introduction into a bay with broad entrance to the sea and exposed it to more energetic waves, similar to the situation Sustainable management of aquatic ecosystems in the 1950s. The marshy grassland and sand-dune demands a deep understanding and ability to predict areas at the mouth of the Sefid Rud have, however, the behavior of the marine environment. Kiashahr remained more or less unchanged mainly because of Lagoon lies immediately east of the mouth of the a huge amount of sedimentation in the river mouth Sefid Rud (river) in the southwest of the Caspian which has reduced the water depth and has kept that ◦ Sea at geographical coordinates on the 39 57 E area from higher and more energetic waves. ◦ and 37 26 N (Figure 1). The lagoon has evolved Waves can profoundly impact the environment in as a result of wide variations in water levels. In the coastal areas (Keddy, 1982; Fonseca and Bell, 1998; early 1970s it was a shallow, brackish coastal lagoon Fonseca et al., 1998a; Ashworth, 2001). Cheong and with fringing marshes in an area of coastal sand- Okada (2001) studied the effects of wave and tidal dunes and grassland; it was fed by local run-off, and actions on the penetration of spilled oil stranded drained north-east through a narrow channel into the on tidal flats, and thus on the tidal flat ecosystem. Caspian Sea, having formed in 1960 as a result of the Waves are responsible for thermal mixing, coastal falling level of the Caspian Sea and development of erosion and accretion. The re-suspending of bed ma- coastal sand spits. The 1.8 m rise in the level of the terials by waves in shallow waters has large effects Caspian Sea since 1978 has converted the wetland upon material balance and water quality, as well. 358 Aquatic Ecosystem Health & Management, 12(4):358–363, 2009. Copyright C 2009 AEHMS. ISSN: 1463-4988 print / 1539-4077 online DOI: 10.1080/14634980903354726 Downloaded from http://read.dukeupress.edu/aehm/article-pdf/12/4/358/886459/358azarmsa.pdf by guest on 29 September 2021 Azarmsa et al. / Aquatic Ecosystem Health and Management 12 (2009) 358–363 359 Figure 1. Location of the Kiashahr sea area. Two jetties were constructed at the Kiashahr lagoon shore wave, NSW, module (Danish Hydraulic Insti- mouth to fix the lagoon entrance and prevent it from tute, 2003) has been used to simulate the wave prop- migration over time. Construction of jetties, more- agation, growth and decay of short period waves in over, has resulted in reduction of wave penetration near-shore areas and to estimate wave heights be- into the lagoon. The objective of this paper is to fore and after construction of jetties on the mouth of determine the wave characteristics in the Kiashahr Kiashahr lagoon. The model is a stationary, direc- sea area and to study the efficiency of these jetties tionally decoupled, parametric model (Holthuijsen in reducing wave heights. et al., 1989) and includes the effects of refraction and shoaling due to varying depth, wave generation Material and methods due to wind (Johnson, 1998), and energy dissipation due to bottom friction and wave breaking (Battjes Wind data were collected from Anzali station and and Janssen, 1978) as well. The effects of current on analyzed to determine wind roses in the study area. these phenomena are also included. The model cov- Deepwater wave characteristics have been deter- ers the whole Kiashahr lagoon and its vicinity with mined by using wind statistics and Sverdrup-Munk- an approximate area of 72 km2 (Figures 2, 3). The Bretschneider, SMB, method (U.S. Army Corps of grid includes 170 × 170 nodal points distributed Engineers, 2002; Azarmsa, 2003). MIKE 21 near- every 50 m in x and y directions. The bathymetry of the study area is modeled with 1:5000 scale. Figure 2. Bathymetry of the study area before jetties construc- tion. Figure 3. Bathymetry of the study area after jetties construction. Downloaded from http://read.dukeupress.edu/aehm/article-pdf/12/4/358/886459/358azarmsa.pdf by guest on 29 September 2021 360 Azarmsa et al. / Aquatic Ecosystem Health and Management 12 (2009) 358–363 Table 1. Model setup information for selected directions. NNW Wind Duration (hour) Wind Speed (m s−1)P%Hs(m)Ts(s)P%Hs(m)Ts(s) 3 2 5.00 0.2 2.2 4.86 0.2 2.2 5 2.77 0.6 3.3 3.06 0.6 3.3 8 1.09 0.9 4.0 1.18 0.9 4.0 11 0.41 1.3 4.7 0.42 1.3 4.7 14 0.10 1.8 5.2 0.11 1.8 5.2 17 0.04 2.0 5.5 0.03 2.0 5.5 20 0.01 2.6 6.0 0.01 2.6 6.0 6 2 0.45 0.3 3.1 0.45 0.3 3.1 5 0.23 0.9 4.6 0.32 0.9 4.6 8 0.09 1.6 5.7 0.12 1.6 5.7 11 0.03 2.3 6.6 0.05 2.3 6.6 14 0.01 3.0 7.4 0.02 3.0 7.4 9 2 0.05 0.3 3.0 0.05 0.3 3.0 5 0.03 1.3 5.7 0.02 1.3 5.7 8 0.01 2.1 7.0 0.02 2.1 6.9 NE E Duration (hour) Wind Speed (m s−1)P%Hs(m)Ts(s)P%Hs(m)Ts(s) 3 2 5.45 0.2 2.2 4.18 0.2 2.2 5 1.96 0.6 3.3 2.15 0.6 3.3 8 0.39 0.9 4.0 0.22 0.9 4.0 11 0.14 1.3 4.7 0.01 1.3 4.7 14 0.02 1.8 5.2 6 2 0.54 0.3 3.1 0.43 0.3 3.1 5 0.14 0.9 4.6 0.25 0.9 4.6 8 0.03 1.6 5.7 0.02 1.6 5.7 9 2 0.04 0.3 3.0 0.03 0.3 3.0 5 0.01 1.3 5.7 0.02 1.3 5.7 8 0.01 2.1 7.0 Considering yearly deepwater wave characteris- to 20 m s−1 in these directions. Local wind duration tics in the region, 50 regional models (Table 1) were ranges from 3 to 9 hours. Northeasterly (8.73%) set up to model wave conditions in the Kiashahr and easterly (7.31%) winds with maximum speed sea area before and after construction of the jetties of 14 m s−1 and 11 m s−1, respectively, are in the (100 models in total). The probability of occurrence second and third order of importance. Increase in of each specific wind duration and speed class and wind duration and speed results in increase of wave thus, resulted deepwater wave field, is given as P% in height and period, but decrease of the probability of Table 1 for each direction. The model results in- occurrence. The waves with 0.2 m height and 2.2 clude: significant wave height, average wave period, s period are more frequent (19.49%), although the and average wave direction at all nodal points of northerly and northwesterly waves with 3.0 m height model mesh in shallow waters for each model set up. and 7.4 s period and yearly probability of occurrence of 0.02% and 0.01%, respectively, are rare, but the Results and discussions most crucial waves in the study area (Table 1). Model results for four representative cases before Winds are calm about 63% of the time. The north- and after construction of the jetties are considered westerly (10.72%) and northerly (10.32%) winds are and discussed here (eight cases in total). Specifi- more dominant (Table 1). Wind speed ranges from 2 cations of their deepwater waves inputted into the Downloaded from http://read.dukeupress.edu/aehm/article-pdf/12/4/358/886459/358azarmsa.pdf by guest on 29 September 2021 Azarmsa et al.
Load more

Recommended publications
  • CONTROL of .ALLUVIAL RIVERS by STEEL JETTIES By
    CONTROL OF .ALLUVIAL RIVERS BY STEEL JETTIES by E. 1. Carlson and R. A. Dodge, Jr. A paper to be presented at The First Water Resources Engineering Conference of The American Society of Civil Engineers, Omaha, Nebraska, May 14-18, 1962 CONTROL OF ALLUVIAL RIVERS BY STEEL JETTIES by E. J. Carlsonl / and R. A. Dodge, Jr. 2 / SYNOPSIS Both field and laboratory studies were conducted to refine the methods used in the design of steel jetty fields for river aline- ment. A set of dimensionless friction head-loss curves, verified by model studies are developed and described. Using the developed curves and reconnaissance field data, a method is given for predict- ing the changes in a riverbed after the designed jetty field is installed. /Head, Sediment Investigations Unit, Hydraulics Branch, Division of Engineering Laboratories, Bureau of Reclamation, Denver, Colorado. 2 /Hydraulic Engineer, Hydraulics Branch, Division of Engineering Laboratories, Bureau of Reclamation, Denver, Colorado. INTRODUCTION Steel jacks and jetties have been used successfully by the Corps of Engineers, highway departments, railway companies, and others to prevent damage to riverbanks, levees, bridge abutments, and other structures. The Bureau of Reclamation and the Corps of Engineers are using them to stabilize the channel of the Rio Grande within the floodway in the Middle Rio Grande Valley. (1)1 / The individual jack unit consists of three angle irons, 12 or 16 feet in length placed at 90° angles in three planes and joined at their cen- ters, Figure 1. Wire is laced through the angle irons in a standard pattern to tie them together.
    [Show full text]
  • Dealing with Erosion: the Spectrum of Coastal Erosion Control Methods
    2ND ANNUAL CAPE COASTAL CONFERENCE Linking Science with Local Solutions and Decision-Making Dealing With Erosion: The Spectrum of Coastal Erosion Control Methods Greg Berman (Woods Hole Sea Grant & Cape Cod Cooperative Extension) Photo Credit: Ted Keon Climate Change Impacts In Coastal Environments 34 5 12 Coastal Adaptation On Cape Cod we manage at parcel scale http://www.ipcc.ch/ipccreports/sres/regional/index.php?idp=223 The Spectrum of Coastal Erosion Control Methods Why protect properties……..? Town of Brewster example The Facts The Implications Value = $333,000,000 (don’t want takings) Only ~1% of properties To keep the same revenue, ~3% of town area the tax rate would go from 8.18 to 9.06 but they make ~10% of the real estate taxes or ~$300 per household The Spectrum of Coastal Erosion Control Methods • Do nothing 1. Will system recover by itself? 2. How far is the structure from the water? 3. Grandfathering protects structures (not lawn) before August 10, 1978 Photo Credit: Ann McNichol The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation Plant Natives: Root systems stabilize. Take up water. Break the impact of raindrops or wave-splash. Slow down runoff Remove Invasive The Spectrum of Coastal Erosion Control Methods • Do nothing • Vegetation • Re-grade The Spectrum of Coastal Erosion Control Methods • Do nothing Horizontal • Vegetation • Re-grade • Managed retreat V E R T I C A L The Spectrum of Coastal Erosion Control Methods • Do nothing Photo Credit: Ted Keon • Vegetation • Re-grade • Managed retreat • Beach
    [Show full text]
  • Beach Nourishment Effects Østerstrand Fredericia - Denmark 2017
    Beach Nourishment Effects Østerstrand Fredericia - Denmark 2017 Juni 2020 Project Building with Nature (EU-InterReg) Start date 01.11.2016 End date 01.07.2020 Project manager (PM) Ane Høiberg Nielsen Project leader (PL) Per Sørensen Project staff (PS) Henrik Vinge Karlsson Time registering 402412 Approved date 26.06.2020 Signature Report Beach nourishment effects – Østerstrand, Frederica, Denmark Author Henrik Vinge Karlsson and Per Sørensen Keyword Beach nourishment, Nourishment design, Coastal protection, Building with nature, BWN, Fredericia, Østerstrand. Distribution www.kyst.dk, www.northsearegion.eu/building-with-nature Referred to as Kystdirektoratet (2020), Beach nourishment effects – Østerstrand, Frederica; Lemvig. 2 Beach Nourishment Effects Contents 1. Introduction ................................................................................................. 5 1.1 Description of Study site .............................................................................................................................5 1.2 Division of study stretch..............................................................................................................................7 1.3 Description of Nourishment ......................................................................................................................7 1.4 Research design ..............................................................................................................................................8 1.4.1 Research questions..............................................................................................................................................................................................................................................9
    [Show full text]
  • COASTAL HAZARDS Too Many People Living Too Close to the Edge of a Rising Sea
    COASTAL HAZARDS Too Many People Living Too Close To The Edge Of A Rising Sea A Growing Challenge For The 21st Century This Report Is Part Of The Ocean On The Edge Series Produced By The Aquarium Of The Pacific As Products Of Its National Conference—Ocean On The Edge: Top Ocean Issues, May 2009 2 COASTAL HAZARDS Ocean on the Edge: Top Ocean Issues Making Ocean Issues Come Alive for the Public The conference brought together leading marine scientists and engineers, policy-makers, film-makers, exhibit designers, informal science educators, journalists and communicators to develop a portfolio of models for communicating major ocean issues to the public. This report is one of a series of reports from that conference. The reports include: Coastal Hazards, Marine Ecosystems and Fisheries, Pollution in the Ocean, and Critical Condition: Ocean Health and Human Health. There is also a series of briefer reports on film-making, kiosk messaging design, and communicating science to the public. All reports are available at www.aquariumofpacific.org COASTAL HAZARDS 3 4 COASTAL HAZARDS Acknowledgements Support for the “Ocean on the Edge Conference: Issues” held in May 2009, at Long Beach Top Ocean Issues” was provided by NOAA, Convention Center. Participants in the the National Science Foundation, Southern Coastal Hazards workshop session included: California Edison, SAVOR, the Long Beach Dr. Robert Dean, Dr. R. A. Dalrymple, Dr. Convention Center, and the Aquarium of the Conrad C. Lautenbacher, Jr., Dr. Jerry R. Pacific. Schubel, and Dana Swanson. Sandy Eslinger was the facilitator of the session. Leah Young We are grateful to the Conference’s National and Margaret Schubel were the rapporteurs.
    [Show full text]
  • Mitigation of Channel Shoaling at a Sheltered Inlet Subject to Flood Gate Operations
    Journal of Marine Science and Engineering Article Mitigation of Channel Shoaling at a Sheltered Inlet Subject to Flood Gate Operations Laura Lemke * , Matthew S. Janssen and Jon K. Miller Coastal Engineering Research Group, Davidson Laboratory, Stevens Institute of Technology, Hoboken, NJ 07030, USA; [email protected] (M.S.J.); [email protected] (J.K.M.) * Correspondence: [email protected] Received: 30 September 2020; Accepted: 29 October 2020; Published: 31 October 2020 Abstract: A comprehensive case study of Keansburg Inlet (New Jersey, USA) is presented with the objective of evaluating inlet management alternatives and assessing the influence of an operational flood gate on channel shoaling. The goal of the research is determining the most effective strategy for minimizing the frequency of maintenance dredging. This study compares the effectiveness of (1) traditional structural solutions; (2) modified dredging templates; and (3) assesses the influence of the flood gate operations during conditions representative of a typical year. Alternative analysis is completed using a coupled hydrodynamic–wave model (Delft3D-Flexible Mesh (FM)) with Real Time Control to simulate morphological changes. The model was calibrated and evaluated using collected field data. Water levels are reproduced within 6% of the spring tide range with lag times less than 20 min. The model results and observations suggest sediment transport is dominated by wave action with pronounced variations in dominant wave direction. The results indicate that changes to the operational dredging, or what the authors have termed broadly as “adaptive dredging techniques”, appear to deliver the most promising improvement. Model results suggest that the current operational procedures of the flood gate do not significantly alter the channel infilling rates and patterns during typical (i.e., non-extreme event) conditions.
    [Show full text]
  • Impacts of Long Jetties Construction on Shoreline Change at the Western Coast of the Gulf of Thailand
    Article Impacts of Long Jetties Construction on Shoreline Change at the Western Coast of the Gulf of Thailand Nathamon Phanomphongphaisarn.1,2,a, Chaipant Rukvichai1,b, and Butsawan Bidorn1,2,c,* 1 Department of Water Resource Engineering, Chulalongkorn University, Bangkok, Thailand 2 WISE Research Unit, Chulalongkorn University, Bangkok, Thailand E-mail: [email protected], [email protected], cbutsawan.p @chula.ac.th (Corresponding author) Abstract. Pranburi Jetties, a pair of long jetties with a length of 800 m and 860 m, have been constructed at the Pranburi River inlet, located on the western coast of the Gulf of Thailand since 1999 to stabilize the river mouth. The purposes of this study were to evaluate the responses of shoreline due to the construction of Pranburi Jetties, and the accuracy of the One-Line model (OLM) on predicting the shoreline change due to construction. Based on the shoreline positions retrieving from aerial photographs and satellite imagery during 1967- 2018, the difference in shoreline evolution before and after the construction of the jetties was evaluated using ArcGIS and Digital Shoreline Analysis System. The predicted shorelines using the One-Line model were compared with the image-analyzed shorelines for evaluating the accuracy of the model. The results indicated that the construction of Pranburi Jetties had caused the shoreline accretion at the vicinity of the jetties with the maximum accretion of up to 300 m in 2018. The land growth of 16.2 and 9 ha took place at the northern and southern coasts, respectively. The percentage of errors between the predicted and the image- analyzed shoreline varied from 2 to 13,000 percent with an average of 250 percent.
    [Show full text]
  • Large Scale Impacts of Jetties and Training Walls - Experience on the Australian East Coast
    LARGE SCALE IMPACTS OF JETTIES AND TRAINING WALLS - EXPERIENCE ON THE AUSTRALIAN EAST COAST Angus Gordon, Coastal Zone Management and Planning, [email protected] Alexander Nielsen, Advisian Worley Group, [email protected] INTRODUCTION The erosion has continued due to both the realignment of Entrance jetties and training walls have instigated the beach and the net loss of sand blown into the dunes fundamental perturbations to coastal and estuary of Newcastle Bight (Gordon & Roy, 1977). This has processes at several locations on the Australian eastern resulted in the requirement to construct a rock revetment seaboard inducing long term changes to foreshore to protect Mitchell Street and the village (Figure 2). More alignments, tidal current velocities, tidal plane elevations recently it has been necessary to undertake beach and marine ecologies with significant consequences, nourishment to offset the on-going coastal recession. some having been realised only recently. This paper presents examples of long-term impacts of entrance jetties and training walls on coastal and estuary processes, gleaned from experience on the NSW coast. COASTALPROCESSES On coastlines with high transport rates of littoral drift, jetties have trapped sand inducing erosion on down-drift beaches at the Tweed River (Delft 1970) and Coffs Harbour (Lord & van Kerkvoort 1981). Another less-appreciated impact of jetties on coastal alignments has been the changes they can induce in near-shore wave patterns that, in turn, will re-align ocean Figure 1 - Left: Entrance to Newcastle Harbour (circa foreshores significantly (Miller & Nielsen 1995, Klein et al. 1850). Right: Present-day entrance with MEPBAY 1850 2003, Gordon 2011).
    [Show full text]
  • 2.2 State Risk Assessment
    Chapter 2: RISK ASSESSMENT | State Risk Assessment | Cultural Resources Summary » Wildfire 2.2 State Risk Assessment Requirement: 44 CFR §201.4(c)(2)(i): The risk assessment shall include… (i) An overview of the type and location of all natural hazards that can affect the State, including information on previous occurrences of hazard events, as well as the probability of future hazard events, using maps where appropriate; The spatial distribution of the facilities within hazard zones is not easily viewed on a statewide map. Therefore, maps depicting hazard zones and facilities within those zones have only been created at the regional scale. Those maps can be found in section 2.3, Regional Risk Assessments. Oregon Natural Hazards Mitigation Plan | September 2020 163 Chapter 2: RISK ASSESSMENT | State Risk Assessment | Coastal Hazards Summary » Wildfire 2.2.1 Coastal Hazards The Pacific Northwest (PNW) coast of Figure 2-29. Erosion at The Capes Oregon is without doubt one of the most Condominiums, Oceanside, Oregon dynamic coastal landscapes in North America, evident by its long sandy beaches, sheer coastal cliffs, dramatic headlands and vistas, and ultimately the power of the Pacific Ocean that serves to erode and change the shape of the coast. It is these qualities along with its various natural resources that have drawn people to live along its narrow shores. However, coastal communities are increasingly under threat from a variety of natural hazards that all come together along the coastal strip. These include wave-induced coastal erosion (both short and long term), wave runup and overtopping (wave-induced flood hazards), inundation Notes: The Capes, a multi-million dollar condominium of homes by wind-blown sand, coastal complex constructed on an old Holocene dune field landslides, earthquakes, and potentially adjacent to Oceanside.
    [Show full text]
  • Bakers Haulover Inlet Management
    Bakers Haulover Inlet Management 2019 National Conference on Beach Preservation Technology – St. Augustine, Florida T. K. Blankenship, P.E., Yong Chen, Ph.D., P.E., Nina Piccoli, MsC. - Moffatt & Nichol Paul Voight, P.G. Miami-Dade DERM February 7, 2019 Presentation Outline • Inlet Management Plan – Developing & Updating IMP • Bakers Haulover Inlet (Location, history) • Beach Management Challenges • Sediment Budget • Alternatives • Next steps towards IMP Bakers Haulover Inlet – Location Map Port Everglades Bakers Haulover Inlet Government Cut Inlet Management Plan – Florida Statutes Section 161.142, F.S. – • The Legislature finds it is in the public interest to replicate the natural drift of sand which is interrupted or altered by inlets to be replaced and for each level of government to undertake all reasonable efforts to maximize inlet sand bypassing to ensure that beach- quality sand is placed on adjacent eroding beaches. Such activities cannot make up for the historical sand deficits caused by inlets but shall be designed to balance the sediment budget of the inlet and adjacent beaches and extend the life of proximate beach- restoration projects so that periodic nourishment is needed less frequently. Inlet Management Plan • All FDEP Inlet Management Plans https://floridadep.gov/water/beaches- inlets-ports/content/strategic- planning-and-coordination#imp Bakers Haulover Inlet - History 1940 Year BHI modifications 1927 1925 The BHI was constructed along with two short rock rubble jetties. All protective structures along BHI were destroyed by a 1926 hurricane. Permits were issued for the reconstruction of BHI which provided 1927 for the construction of two sheet pile jetties. The integrity of the coastal structures (bulkheads and groins) was compromised due to corrosion and abrasion.
    [Show full text]
  • Chapter 3 EM 1110-2-1100 HISTORY of COASTAL ENGINEERING (Part I) 30 April 2002
    Chapter 3 EM 1110-2-1100 HISTORY OF COASTAL ENGINEERING (Part I) 30 April 2002 Table of Contents Page I-3-1. Ancient World ............................................................ I-3-1 I-3-2. Pre-Roman Times ........................................................ I-3-1 I-3-3. Roman Times ............................................................ I-3-3 I-3-4. Modern Age .............................................................. I-3-4 I-3-5. Civil Engineer Era ........................................................ I-3-5 I-3-6. United States Army Corps of Engineers .................................... I-3-6 I-3-7. Coastal Engineering in the United States .................................. I-3-10 a. Nineteenth century projects ................................................ I-3-10 b. Nineteenth century coastal engineering ...................................... I-3-11 c. Early coastal development and shore protection ................................ I-3-12 d. Early 20th century beach development and the Engineering Advisory Board on Coastal Erosion ......................................................... I-3-13 e. American Shore and Beach Preservation Association ........................... I-3-13 f. The Board on Sand Movement and Beach Erosion .............................. I-3-15 g. The Beach Erosion Board ................................................. I-3-15 h. BEB focus on basic research ............................................... I-3-16 i. Dalecarlia reservation and World War II ....................................
    [Show full text]
  • Deconstructing a Jetty to Rectify the Downdrift Erosion
    Journal of Sustainability Science and Management eISSN: 2672-7226 Volume 15 Number 2, February 2020: 79-88 © Penerbit UMT DECONSTRUCTING A JETTY TO RECTIFY THE DOWNDRIFT EROSION CHERDVONG SAENGSUPAVANICH Faculty of International Maritime Studies, Kasetsart University, Sri Racha Campus, 199 Moo 6 Sukhumvit Rd., Tungsukla, Sri Racha, Chonburi, 20230, Thailand. *Corresponding author: [email protected] Abstract: A jetty is a coastal structure constructed across the surf zone to prevent sediment deposition at a river mouth. It creates updrift accumulation and downdrift erosion. Deconstructing the jetty may restore the situation but create another problem. This study used the Cha-am beach in Thailand to simulate future shoreline positions under different scenarios. The main tool used in the study was the software package LITPACK. The calibrated simulations showed that, if no action was taken, the updrift part of the beach would be widened by as much as 130 m in 25 years but the downdrift side of the jetty would experience severe coastal erosion. Deconstructing the jetty would alternate the outcome. The area where the erosion was foreseen along the downdrift shoreline would not occur anymore. The sediment once intercepted by the jetty would move to pass the inlet. However, the updrift shoreline would adjust its alignment, eroding existing houses and other buildings. While jetty deconstruction would restore the downdrift part of the beach, it would at the same time destroy some properties along the updrift section. Removing the jetty may experience great social resistance. Decision- makers should be equipped with adequate information and coastal engineering can provide some necessary inputs.
    [Show full text]
  • SUPPLEMENT Revised Final Environmental Assessment
    SUPPLEMENT To the Revised Final Environmental Assessment Columbia River at the Mouth, Oregon and Washington Rehabilitation of the Jetty System at the Mouth of the Columbia River Clatsop County, Oregon, and Pacific County, Washington May, 2013 Supplemental EA, South Jetty Foredune Augmentation Related to Rehabilitation of Jetty System at MCR Table of Contents: 1. Introduction .......................................................................................................................................... 1 2. Brief Description of Project History and Need ...................................................................................... 2 3. Revised Preferred Alternative ............................................................................................................... 5 3.1. Updated Details for South Jetty Foredune Augmentation ........................................................... 6 3.2. Updated Construction Access, Storage and Staging Areas ......................................................... 11 4. Affected Environment ......................................................................................................................... 14 4.1. Aquatic Resources ....................................................................................................................... 14 4.1.1. Surrounding Water Resources ............................................................................................ 14 4.1.2. Wetlands ............................................................................................................................
    [Show full text]