• Title/Summary/Keyword: change of coastal area

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Conservation Method of Sindu-ri Coastal Dune using System Dynamics (시스템 다이내믹스를 이용한 신두리 해안사구의 보전방안)

  • Seok, Youngsun;You, Soojin;Song, Kihwan;Chon, Jinhyung
    • Korean System Dynamics Review
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    • v.16 no.1
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    • pp.5-23
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    • 2015
  • The purpose of this study is to analyze the land-use changes in the coastal areas using system dynamics modeling and to provide directions for effective management to maintain coastal dune areas. This research process consists of four steps: First, we built the basic model based on the causal loop diagram which was analyzed the land-use change of Sindu-ri Coastal Dune. Second, a time series land-use change map using Arc Map was established. Third, the validity of the basic model was tested. Finally, three simulations were performed for the cut over area($100,000m^2/y$, $150,000m^2/y$, $200,000m^2/y$) of windbreak for maintaining the coastal dune areas. Simulation of the basic model showed that the area of the coastal dune will be consistently decreased. Based on the simulation, if windbreak were cut down $150,000m^2/y$, windbreak area will be restored to the target area in 2019. This study has the limitation which the simulation is progressed with a limited variable: area. Therefore, the modeling of coastal dune should be reflected various variables in the further study.

The design load factor of road structure considering long-term coastal geographic change (해안지형의 장기적 변화에 따른 도로 구조물 설계하중 고려 요소에 관한 연구)

  • Bae, Sun-Hak;Kang, Sang Hyeok
    • Journal of The Geomorphological Association of Korea
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    • v.20 no.1
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    • pp.75-83
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    • 2013
  • Human-induced modifications in coastal area may cause strong geomorphic responses by disturbing sediment supply, transport and deposition regimes. Morever, engineering structure have been built to stabilize coastal change, these effort impact on other morphologic change. In case of coastal area, there are lack of sediment yield data. This study focus on the tendency of long-term shoreline change, estimate method od sediment discharge which is a major factor of coastal change and adduced to way for considering design load influenced to coastal road.

Characteristics of Ground Water Capture Zone according to Pumping Rate (지하수 양수량에 따른 지하수유동 및 포획구간 특성 변화)

  • Ahn, Seung-Seop;Park, Dong-Il;Oh, Young-Hun
    • Journal of Environmental Science International
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    • v.22 no.7
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    • pp.895-903
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    • 2013
  • This study analyzed on characteristics of the ground-water capture zone in coastal areas and mid-mountainous area according to pumping rate. For this study, it targeted Jejudo island where is the volcanic island. To analyze, MODFLOW model and MODPATH model, which are the ground-water flow analysis models, were used. As a result of research, the following conclusions could be obtained. As a result of analyzing influence of a change in pumping time upon length of capture zone, the length of capture zone in coastal area was indicated to be greater in the changing ratio compared to the length of capture zone in mid-mountainous area. Next, in the coastal area, the pumping rate and the capture-zone length are changing similarly. However, in mid-mountainous area, the length of capture zone was indicated to grow when the pumping rate comes to exceed 1,500m3/day. As a result of analyzing influence of a change in pumping time upon capture area, the tendency of a change in the area was indicated similarly in coastal areas and mid-mountainous area. Especially, it could be known that the larger pumping rate leads to the more definite increase in tendency to a change in capture area. Based on this study, it was allowed to be possibly used in the suitable pumping rate in coastal areas and mid-mountainous area of the volcano island in the future. A follow-up research is judged to necessarily analyze the influence of tubular-well group upon capture zone by additionally analyzing a change in capture zone targeting the concentrated tubular well.

Numerical Analysis for Wave Propagation and Sediment Transport with Coastal Vegetation (연안식생에 의한 표사이동 특성에 관한 수치해석)

  • Lee, Seong-Dae
    • Journal of Ocean Engineering and Technology
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    • v.21 no.5
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    • pp.18-24
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    • 2007
  • The environmental value of coastal vegetation has been widely recognized. Coastal vegetation such as reed forests and seaweed performs several useful functions, including maintaining water quality, supporting fish (and, thus, fisheries), protecting beaches and land from wave attack, stabilizing sea beds and providing scenic value. However, studies on the physical and numerical process of wave propagation, sediment transport and bathymetric change are few and far between compared to those on the hydrodynamic roles of coastal vegetation. In general, vegetation flourishing along the coastal areas attenuates the incident waves through momentum exchange between stagnated water mass in the vegetated area and rapid mass in the un-vegetated area. This study develops a numerical model for describing the wave attenuation and sediment transport in a wave channel in a vegetation area. By comparing these results, the effects of vegetation properties, wave properties and model parameters are clarified.

A Study on the Spatial Change of Busan Nambin Coast from 1895 to 1936 (1895~1936년 부산 '남빈해안(南濱海岸)'의 공간변화 연구)

  • Song, Hye-Young
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.6
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    • pp.59-68
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    • 2019
  • The purpose of this study was to analyze the spatial change of coastal area called Nampo-dong in Busan. And then the subject of research was chiefly concentrated upon the development of southern coast and the land-reclamation based on the commercial facilities after the opening port. There were various reclamation projects in the coastal area of Japanese settlement under the Rule of Japan. Busan Nambin Coast(Currently, Nampo-dong) was one of typical reclamation projects conducted in the southern seashore. Due to the characteristic of coastal area, fishery was developed well and the entertainment industry also grew rapidly with the characteristic of the short distance of urban centre. In this study, we investigated the process of reflecting the characteristic of spatial change that were pursued by communities at that time, particularly through the establishment and change of buildings.

Climate change impact on seawater intrusion in the coastal region of Benin

  • Agossou, Amos;Yang, Jeong-Seok
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.157-157
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    • 2022
  • Recent decades have seen all over the world increasing drought in some regions and increasing flood in others. Climate change has been alarming in many regions resulting in degradation and diminution of available freshwater. The effect of global warming and overpopulation associated with increasing irrigated farming and valuable agricultural lands could be particularly disastrous for coastal areas like the one of Benin. The coastal region of Benin is under a heavy demographic pressure and was in the last decades the object of important urban developments. The present study aims to roughly study the general effect of climate change (Sea Level Rise: SLR) and groundwater pumping on Seawater intrusion (SWI) in Benin's coastal region. To reach the main goal of our study, the region aquifer system was built in numerical model using SEAWAT engine from Visual MODFLOW. The model is built and calibrated from 2016 to 2020 in SEAWAT, and using WinPEST the model parameters were optimized for a better performance. The optimized parameters are used for seawater intrusion intensity evaluation in the coastal region of Benin The simulation of the hydraulic head in the calibration period, showed groundwater head drawdown across the area with an average of 1.92m which is observed on the field by groundwater level depletion in hand dug wells mainly in the south of the study area. SWI area increased with a difference of 2.59km2 between the start and end time of the modeling period. By considering SLR due to global warming, the model was stimulated to predict SWI area in 2050. IPCC scenario IS92a simulated SLR in the coastal region of Benin and the average rise is estimated at 20cm by 2050. Using the average rise, the model is run for SWI area estimation in 2050. SWI area in 2050 increased by an average of 10.34% (21.04 km2); this is expected to keep increasing as population grows and SLR.

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Application of Remote Sensing and GIS technology for monitoring coastal changes in estuary area of the Red river system, Vietnam

  • Lan, Pham Thi;Son, Tong Si;Gunasekara, Kavinda;Nhan, Nguyen Thi;Hien, La Phu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.31 no.6_2
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    • pp.529-538
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    • 2013
  • Coastline is the most dynamic part of seascape since its shape is affected by various factors. Coastal zone is an area with immense geological, geomorphological and ecological interest. Monitoring coastal change is very important for safe navigation, coastal resource management. This paper shows a result of monitoring coastal morphological changes using Remote Sensing and GIS. Study was carried out to obtain intensity of erosion, deposition and sand bar movement in the Red River Delta. Satellite images of ALOS/AVNIR-2 and Landsat were used for the monitoring of coastal morphological changes over the period of 1975 to 2009. Band rationing and threshold technique was used for the coastline extraction. Tidal levels at the time of image acquisition varied from -0.89m to 2.87m. Therefore, coastline from another image at a different tidal level in the same year was considered to get the corrected coastline by interpolation technique. A series of points were generated along the coastal line from 1975 image and were established as reference points to see the change in later periods. The changes were measured in Euclidean distances from these reference points. Positive values represented deposition to the sea and negative values are erosion. The result showed that the Red river delta area expanded to the sea 3500m in Red river mouth, and 2873m in Thai Binh river mouth from 1975 to 2009. The erosion process occurred continuously from 1975 up to now with the average magnitude 23.77m/year from 1975 to 1989 and 7.85m/year from 2001 to 2009 in Giao Thuy area. From 1975 to 2009, total 1095.2ha of settlement area was eroded by sea. On the other hand, land expanded to the sea in 4786.24ha of mangrove and 1673.98ha of aquaculture.

An Analysis of the Coastal Topography and Land Cover Changes in the Haeundae Beach (해운대 해수욕장의 해안지형 및 토지피복 변화 분석)

  • Yang, Ji-Yeon;Choi, Chul-Uong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.1
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    • pp.101-115
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    • 2006
  • As coastal erosion is increasing sharply because of sudden changes in the natural environment and increases in artificial development, the problem of coastal erosion become an important issue, socially and economically. To building the data which needed to grasp the situation and find a solution, we need the monitoring system for long-term. In this study, we analyzed the coastal topography and land cover changes in the Haeundae Beach during 60 years. The Haeundae Beach is the most famous beach in the country and coastal erosion are going on. First, we analyzed the change of coastal topography by calculated the coastline and area of the beach using aerial photos during 60 years. We extracted the coastline by digitized on aerial photo and corrected the height of tide level using sounding and GPS survey data. And we computed the area of beach and analyzed the change of area during 60 years. Second, we analyzed the change of land cover using landcover map. We made the detailed landcover map by on-screen digitizing and estimated the soil loss for the area nearby Haeundae Beach. As a result, we could see that the coastline get nearer to land and the area of beach has been reduced in general. We think that interception of sand supply by the development is the artificial cause of coastal erosion. The result of this study would be useful in long-term coastal monitoring and to analyze the cause of coastal environment change. We expect that the result is available on the coastal information system.

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Systems Thinking for the Land Use and Landscape Value of Coastal Dune (해안사구의 토지이용과 경관가치에 대한 시스템 사고)

  • Seok, Youngsun;Song, Kihwan;Chon, Jinhyung
    • Korean System Dynamics Review
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    • v.15 no.3
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    • pp.81-104
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    • 2014
  • This study aimed to suggest the directions for the landscape protection of Sindu-ri coastal dune based on its ecological system. The study investigated ecological systems of the coastal dune followed by damage causes of coastal dune according to the land use change, and landscape value of coastal dune in the study area. In order to construct causal-effect feedback loop, systems thinking was performed. Result of this study showed that the area of coastal dune and the amount of sand are maintained by the interaction with sand beach while they are affected by wind direction, wind speed, and dune plants. It was also found that the changes of land use pattern, increasing commercial area, and planted windbreak forest damaged to the coastal dune. In addition, size of coastal dune and growing number of dune plants increased landscape value of coastal dune and tourist draw. However increasing tourists have constantly affected land use changes and have damaged to coastal dune area. In sum, planning for land use regulation, rest-year system areas, promotion and education for coastal dune, dune plants protection, and windbreak management should be taken into account for landscape protection in coastal dune.

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Analysis of the Change in the Area of Haeundae Beach Based on Wave Characteristics (파랑특성을 고려한 해운대 해수욕장의 해빈면적 변화에 관한 연구)

  • Kim, Jong-Beom;Kim, Jong-Kyu;Kang, Tae-Soon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.2
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    • pp.324-339
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    • 2021
  • In this study, we determined the correlation between the wave characteristics and the change in the area of Haeundae Beach, conducted regression analysis between the wave characteristics and the change in beach area, and derived a formula for calculating the change in beach area. The change in beach area was calculated by applying the derived formula to wave observation data corresponding to a period of approximately 10 months, and the formula was subsequently validated by comparing the obtained results with the observed area. It is found that the error associated with the formula for calculating the change in beach area ranges from 1.5 m to 2.7 m based on the average beach width, and the correlation coefficient corresponding to the observed area ranges from 0.91 to 0.94. Furthermore, it is observed that the change in beach area is af ected by the wave direction in the western zone, wave height in the central zone, and wave height and wave period in the eastern zone. These results can contribute to understanding the impact of a coastal improvement project on the beach area fluctuation characteristics of Haeundae Beach and the ef ectiveness of such a coastal improvement project. By applying the aforementioned derived formula to highly accurate wave prediction data, the change in beach area can be calculated and incorporated for predicting significant long-term changes in beach areas. Furthermore, such a prediction can be considered as the basis for making decisions while establishing preemptive countermeasure policies to prevent coastal erosion.