• Title/Summary/Keyword: Coastal erosion

Search Result 301, Processing Time 0.024 seconds

Construction of High-Resolution Topographical Map of Macro-tidal Malipo beach through Integration of Terrestrial LiDAR Measurement and MBES Survey at inter-tidal zone (대조차 만리포 해안의 지상 LiDAR와 MBES를 이용한 정밀 지형/수심 측량 및 조간대 접합을 통한 정밀 지형도 작성)

  • Shim, Jae-Seol;Kim, Jin-Ah;Kim, Seon-Jeong;Kim, Sang-Ik
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.22 no.1
    • /
    • pp.58-66
    • /
    • 2010
  • In this paper, we have constructed high-resolution topographical map of macro-tidal Malipo beach through integration of terrestrial LiDAR measurement and MBES survey data at inter-tidal zone. To acquire the enough information of inter-tidal zone, we have done terrestrial LiDAR measurement mounted on the roof of vehicle with DGPS through go-stop-scan method at the ebb tide and MBES depth surveying with tide gauge and eye staff measurement for tide correction and MSL calculation at the high tide all together. To integrate two kinds of data, we have unified the vertical coordination standard to Incheon MSL. The mean error of overlapped inter-tidal zone is about 2~6 cm. To verify the accuracy of terrestrial LiDAR, RTK-DGPS measurement have done simultaneously and the difference of Z value RMSE is about 4~7 cm. The resolution of Malipo topographical map is 50 cm and it has constructed to DEM (Digital Elevation Model) based on GIS. Now it has used as an input topography information for the storm-surge inundation prediction models. Also it will be possible to use monitoring of beach process through the long-term periodic measurement and GIS-based 3D spatial analysis calculating the erosion and deposition considering with the artificial beach transition and coastal environmental parameters.

Evalution for Joints of Coastal Environments Blocks (Coastal Environments 블록 적용을 위한 연결부 강도평가)

  • Kim, Chun-Ho;Kim, Kwang-Jin
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.13 no.6 s.58
    • /
    • pp.176-182
    • /
    • 2009
  • Other damage can occur due to the preexisting dull structure and installation of nonenvironmental-friendly concrete structure, lack of function for preventing coastal erosion. Increase of personal income and fast spread of the concept of waterfront casued the initiation of many project to improve aging coastal ports. However, none of environment-friendly structure has been developed and pre-existing solid block, igloo block, tunnel block are used commonly. In piers and lighter's wharf where the ships are mooring, resonance by the generation of a reflected wave caused by penetration wave in the port and port wave increases wave heights in the port and makes difficult to maintain the temperature, causes problems in mooring ships and cargo-working, and eventually increase the occurance of damages of the small ships by the collision. Therefore, development of new types of blcok is necessary. To apply Coastal Environments block developed for this reason, it requires allowable bearing capacity evaluation of shear key. For this study, we made test specimen for connecting part of C.E. Block, and conducted friction test of boundary surface. Data obtained by the experiment was analyzed by finite element analysis and assessed the coefficient of friction between C.E. Block and boundary surface.

Assessment and Enhancement of Ecosystem Service on Hasidong Anin Coastal Sand Dune of Ecological and Landscape Conservation Area (하시동·안인사구 생태경관보전지역의 생태계서비스 평가와 증진 방안)

  • Eun-Hye Lee;Choong-Hyeon Oh
    • Korean Journal of Environment and Ecology
    • /
    • v.37 no.5
    • /
    • pp.403-414
    • /
    • 2023
  • This study aimed to evaluate the ecosystem services and environmental sustainability index(ESI) of the Hasidong-Anin coastal sand dune ecological and landscapes conservation area using rapid assessment tools. As a result, the analysis of the environmental sustainability index, derived from the evaluation of ecosystem services in the Hasidong-Anin coastal sand dune ecological and landscapes conservation area, revealed that regulating services, cultural services, and supporting services were all rated below 50%. Especially, cultural and supporting services were identified as lacking. With these results, a SWOT analysis was conducted to develop strategies for enhancing ecosystem services in the Hasidong-Anin coastal sand dune ecological and landscapes conservation area. Six approaches were formulated, involving leveraging strengths as opportunities (SO strategy), minimizing threats using strengths (ST strategy), utilizing opportunities to address weaknesses (WO strategy), and mitigating weaknesses and threats (WT strategy). In the future, when promoting projects to enhance ecosystem services in the Hasidong-Anin coastal sand dune ecological and landscapes conservation area, it will be essential to address issues such as the restoration of currently damaged areas and prevention of future erosion-related damages. This will lead to an elevation of the value of the Hasidong-Anin coastal sand dune ecological and landscape conservation area.

Valuing Cultural Ecosystem Services of Coastal Beaches in Korea (연안 생태계문화서비스 경제적 가치 추정 - 전국 해수욕장을 대상으로 -)

  • Chi-Ok Oh;Miju Kim;Namhee Kim
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.30 no.1
    • /
    • pp.43-57
    • /
    • 2024
  • As coastal areas have a distinct nature with the interaction of the lands and waters, they attract people to enjoy and experience the natural environments physically and intellectually; this generates cultural ecosystem services. Coastal beaches are one of the most common coastal areas for cultural ecosystem services. The purpose of this study was to 1) estimate the economic values of cultural ecosystem services derived from coastal beaches, and 2) expand the estimated values into other beaches across the country using a benefit transfer method. We divided the values of cultural ecosystem services into five different categories based on an extensive literature review: recreation and tourism, landscape and aesthetic, educational, heritage, and inspirational values. The values of tourism and recreation, landscape and aesthetic, and educational services were estimated using the choice experiments. The attributes of the choice experiments consisted of conservation funds, litter, water quality, seascape, landscape, and biodiversity, and the data were collected through online surveys with visitors of 11 representative beaches in Korea. Heritage and inspiration services were estimated using a market goods method based on their expenditures. These values were transferred to 257 beaches across the country. Study results can be used for policy decisions on various restoration and conservation projects caused by coastal erosion and development and on the need and extent of public investments.

Monitoring of Tidal Sand Shoal with a Camera Monitoring System and its Morphologic Change (카메라를 활용한 조석사주 관측시스템 구축 및 지형변화)

  • Lee, Soong-Ji;Lee, Guan-Hong;Kang, Tae-Soon;Kim, Young-Taeg;Kim, Tea-Lim
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.39 no.3
    • /
    • pp.326-333
    • /
    • 2015
  • A tidal sandshoal, called 'Puldeung' in the Daeijackdo Marine Protected Area(DMPA), is facing erosion due to sand mining in the nearby coastal region. To monitor the morphologic change and erosion of Puldeung, a camera monitoring system was established at the top of Song-Ee Mountain in Daeijack Island. The system consists of 2 Cannon digital cameras, Eye-fi memory card/Long-Term Evolution wireless network, and solar power supply. The acquired camera images were analyzed to obtain the area of Puldeung by the following methods: geometric correction of image, identification of shoreline, areal measurement of Puldeung and its error estimation. To compare the Puldeung area with previously measured area of 1.79 km2 at tidal height of 137 cm in 2008 and of 1.59 km2 at tidal height of 148 cm in 2010, we selected images with same tidal heights. The Puldeung area was 1.37 and 1.23 km2 at the tidal height of 137 and 148 cm, respectively. The erosion at DMPA is very severe and thus it is imperative to initiate the morphodynamical study on the seasonal variation and long-term evolution of Puldeung as well as the causes and measures of Puldeung erosion.

Prediction of Cohesive Sediment Transport and Flow Resistance Around Artificial Structures of the Beolgyo Stream Estuary

  • Cho, Young-Jun;Hwang, Sung-Su;Park, Il-Heum;Choi, Yo-Han;Lee, Sang-Ho;Lee, Yeon-Gyu;Kim, Jong-Gyu;Shin, Hyun-Chool
    • Fisheries and Aquatic Sciences
    • /
    • v.13 no.2
    • /
    • pp.167-181
    • /
    • 2010
  • To predict changes in the marine environment of the Beolgyo Stream Estuary in Jeonnam Province, South Korea, where cohesive tidal flats cover a broad area and a large bridge is under construction, this study conducted numerical simulations involving tidal flow and cohesive sediment transport. A wetting and drying (WAD) technique for tidal flats from the Princeton Ocean Model (POM) was applied to a large-scale-grid hydrodynamic module capable of evaluating the flow resistance of structures. Derivation of the eddy viscosity coefficient for wakes created by structures was accomplished through the explicit use of shear velocity and Chezy's average velocity. Furthermore, various field observations, including of tide, tidal flow, suspended sediment concentrations, bottom sediments, and water depth, were performed to verify the model and obtain input data for it. In particular, geologic parameters related to the evaluation of settling velocity and critical shear stresses for erosion and deposition were observed, and numerical tests for the representation of suspended sediment concentrations were performed to determine proper values for the empirical coefficients in the sediment transport module. According to the simulation results, the velocity variation was particularly prominent around the piers in the tidal channel. Erosion occurred mainly along the tidal channels near the piers, where bridge structures reduced the flow cross section, creating strong flow. In contrast, in the rear area of the structure, where the flow was relatively weak due to the formation of eddies, deposition and moderated erosion were predicted. In estuaries and coastal waters, changes in the flow environment caused by artificial structures can produce changes in the sedimentary environment, which in turn can affect the local marine ecosystem. The numerical model proposed in this study will enable systematic prediction of changes to flow and sedimentary environments caused by the construction of artificial structures.

Sensitivity Analysis and Parameter Evaluation of a Distributed Model for Rainfall-Runoff-Soil Erosion-Sediment Transport Modeling in the Naesung Stream Watershed (내성천 유역의 강우-유출-토양침식-유사이송 모의를 위한 분포형 모형의 민감도 분석 및 매개변수 평가)

  • Jeong, Won Jun;Ji, Un
    • Journal of Korea Water Resources Association
    • /
    • v.47 no.12
    • /
    • pp.1121-1134
    • /
    • 2014
  • The distributed watershed model of rainfall-runoff-soil erosion-sedimen transport was constructed for the Naesung Stream Watershed with high potentiality and risk of sediments produced by soil erosion. The sensitivity analyses of roughness coefficient and hydraulic conductivity which affected the modeling results of runoff and sediment concentration were performed in this study. As a result, the change of the roughness coefficient for the forest area from 0.4 to 0.45 did not affect the change in runoff and stream discharge and the average value and range of sediment concentration were also insignificantly increased with few difference. As a result of the sensitivity analysis of the hydraulic conductivity, the total amount of runoff and maximum runoff were gradually increased as the hydraulic conductivity was reduced. In the case of sediment concentration modeling, the average and the range of sediment concentration for all stations were increased as the hydraulic conductivity was decreased. For the Hyangseok Station, in case of the hydraulic conductivity reduced by 50%, the simulation result of sediment concentration was most similar to the estimated value by the sediment rating curve.

A Practical Algorithm to Simulate Erosion of On-Shore Zone (실용적 해안선 후퇴 반영 알고리즘)

  • Kim, Hyoseob;Lee, Jungsu;Jin, Jae-Youll;Jang, Changhwan
    • Journal of Wetlands Research
    • /
    • v.15 no.3
    • /
    • pp.423-430
    • /
    • 2013
  • An algorithm to allow shoreline movement during numerical experiment on sediment transport, deposition or resuspension for general coastal morphology is proposed here. The bed slope near shoreline, i.e. mean sea level, is influenced by bed material, tidal current, waves, and wave-induced current, but has been reported to remain within a stable range. Its annual variation is not large, either. The algorithm is adjusting the bathymetry, if the largest bed slope within shoreline band exceeds a given bed slope due to continuous erosion at zones below the shoreline. This algorithm automatically describes retreat of shoreline caused by erosion, when used within a numerical system. The algorithm was tested to a situation which includes a continuous dredging at a point, and showed satisfactory development of concentric circle contours. Next, the algorithm was tested to another situation which includes sinking of eroded part of bed plate, and produced satisfactory results, too. Finally, the algorithm was tested to a movable-bed laboratory experimental conditions. The shoreline movement behind detached breakwater was reasonably reproduced with this algorithm.

Scientific Visualization of Oceanic Data (GIS정보를 이용한 해양자료의 과학적 가시화)

  • Im, Hyo-Hyuc;Kim, Hyeon-Seong;Han, Sang-Cheon;Seong, Ha-Keun;Kim, Kye-Yeong
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2006.06a
    • /
    • pp.195-196
    • /
    • 2006
  • Recently, there are increasing need to make a synthetic assessment about oceanic data which is collected over the various scientific field, in addition to just gathering oceanic data. In this study, we made a basic map using satellite image, aerial photo, multi-beam data, geological stratum data etc. And as well we are producing comprehensive SVT(Scientific Visualization Toolkit) which can visualize various kinds of oceanic data. These oceanic data include both survey data such as tidal height, tide, current, wave, water temperature, salinity, oceanic weather data and numeric modelling results such as ocean hydrodynamic model, wave model, erosion/sediment model, thermal discharged coastal water model, ocean water quality model. In this process, we introduce GIS(Geographic Information System) concepts to reflect time and spatial characteristics of oceanic data.

  • PDF

A Study on the Eco-Environmental Change of Coastal Area by the Sea Level Rise (해수면 상승에 따른 해안지역 생태환경 변화)

  • Kim, Nam-Shin;Lee, Chang-Seok
    • Journal of the Korean Association of Geographic Information Studies
    • /
    • v.13 no.3
    • /
    • pp.53-63
    • /
    • 2010
  • The global sea level rise has an effect on eco-environmental change by the inundation and erosion in the coastal area. Forecasting model on the change of morpho-ecological environments by the sea level change will give us information for coastal area management by predicting environmental changes of the up-coming future. This research aimed to foresee eco-environmental changes by the sea level rise in coastal area. Prediction model used SLAMM model developed to forecast coastal changes by IPCC scenario. The model predicted centennial environmental changes in the mouth of Han river and Nakdong river, Suncheon and Hampyeung bay as case areas. To sum up the research findings, in the estuary of the Han river, tidal flat was gradually disappeared from the year 2075, scrubmarsh and saltmarsh belts were developed. In the Nakdong River estuary, scrubmarsh was decreased from the year 2025, tidal flat was deposited from the year 2050, and also, the Gimhae plain was partially inundated, and wetlands were formed. In the Hampyeung bay, saltmarsh was deposited in the year 2025, tidal flat expanded until 2050 was partially submerged after that time. Tidal flat of Suncheon bay was disappeared by the inundation after 2025, and saltmarsh was developed in the embayment.