• Water for future
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• v.25 no.3
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• pp.65-77
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• 1992

The purpose of this study is to analyse existing hysteresis models and to propose a new type of model. The existing hysteresis models are classified by three types: interpolation model, scaling model and domain model, of which the domain model is based on the theoretical approach. Models which need one branch of hysteresis loop for calibration are developed based on the independent domain concept, however, they are not successful to accurately simulate the real data and Rubicon Sandy Loam and Dune Sand. There is a possibility that a new model is based on the dependent domain model considering the pore blockage effect against air entry for homogeneous porous media(modelIII-1, Mualem, 1984). Concludingly, a new type of hysteresis model is proposed by simplifying ModelIII-1 using a proper assumption.

• Journal of Ecology and Environment
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• v.37 no.2
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• pp.81-90
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• 2014

This study examined the main factors affecting the distribution of Phytolacca americana, an exotic plant species in Korea, in coastal sand dunes. The areas examined from June 2004 to February 2006 were in Sindusagu where was located on Sindu-ri, Wonbuk-myen, Taean-gun, Chungcheongnam-do. The vegetation, sediment properties, sizes and ages of Robinia pseudoacacia, P. americana and Pinus thnunbergii and spatial distribution of P. americana were assessed. Firstly, correlation coefficients (CC) between P. americana's root biomass and sediment properties were not significant. Secondly, of the four community types, P. americana was not in the mixed herbaceous community and its density was the highest in the P. thunbergii-R. pseudoacacia and R. pseudoacacia community The Poisson distribution analysis revealed the distribution of P. americana to be severely clumped. The root biomass of P. americana and the basal area of R. pseudoacacia were significantly correlated, but the CCs between P. thunbergii and other two species were not significant. The ages of P. americana and R. pseudoacacia in a quadrat were significantly correlated. Thirdly, P. americana's ages in a quadrat were mostly similar to each other. Therefore, the spatial distribution of P. americana was largely influenced by R. pseudoacacia but not by the sediment properties, and plants in a narrow area were concurrently germinated.

• Journal of Environmental Science International
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• v.12 no.2
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• pp.151-155
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• 2003

The resources conservation system is comprehended, making Taean-haean National Park a research material by applying the fact of landowning, designating an LOP and Korea and Japan's Natural Park Act. Following conclusions were obtained in this study; Most of land areas of the National Park are privately owned; Only a few have been designated as Natural Reservation, a core reserved area on LOP, and a sandy beach, a sand dune, a sand spit, a tidal flat, a wetland, etc are distributed in the natural environment area so they were exposed to development; As seen in most of coastal type of National Parks, 13 commercial beaches are established. The annual rush to the beaches appears in July and August; Sand dune areas that have to be managed in terms of conservation, are turned into beaches. Moreover, the collective facilities areas are randomly developed. So they fail to function originally; The current Natural Park Act has no systematic devices for conservation of the natural resources on the seashore or offshore.

• Journal of the Korean Society for Marine Environment & Energy
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• v.5 no.3
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• pp.10-15
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• 2002

The assessment of PIV to measure the mean velocity and turbulence was carried out over a train of fixed two-dimensional dunes. The agreement between the PIV and LDV is good enough even in regions of flow reversals and high shear. Though limited in the wall normal direction field-of-view, PIV provides instantaneous flow fields, which reveal the complex nature of flow over dunes, as well as more sophisticated analyses such as two-point space correlation and quadrant analysis with a reasonable accuracy The present study is expected to be directly applied to more complex flow such as sediment transport.

• Journal of the Korean Geotechnical Society
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• v.29 no.11
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• pp.49-60
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• 2013

The plan for major design-build projects of railway link among countries in gulf area (GCC) and freight rail construction is recently announced, but Korean companies have a hard time tendering due to special geotechnical condition in the Middle East. The major geotechnical risks during railway construction in the Middle East are related to ground improvement of soft Sabkha ground, wind-blown sand mitigation measure, dune sand compaction, and construction of large-scale cut and embankment. In this study, the characteristics of special geotechnical condition and potential geotechnical risks during railway construction in the Middle East are discussed on the basis of field observation, literature review, and field and laboratory test results.

• The Korean Journal of Ecology
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• v.7 no.2
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• pp.74-84
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• 1983

The dominant species of the sand vegetation in the western coast of Korea were Carex pumila, Ischaemum antheporoides, Calystegia soldanella, Carex kobomugi and Imperata cylindrica var. koenigii. The salt content of the sand dune soil and of the atmosphere of surveyed areas ranged from 3.93 to 13.86 mg% and from 25.81 to 168.86mg% respectively. Between the salt content of the atmosphere and that of the soil positive relationship was found. Species density and Simpson's index increased with the distance from the coast, the former was exponential, however, the latter was linear. The composition of biological types in the investigated stands were H-D4-R1-3-e or H-D4-R1-3-t. Relative numbers of psammophytes and rhizome psammophytes decreased with the distance from the coast, but those of other plants increased. The standing crop of the sand dune vegetation ranged from 0.04 to 491.64g/m2 and the average 27.77g/m2. This was varied as the stands and showed a linear increment as the distance from the coast was increased. The salt content of atmosphere significantly affected the density, T/R ratio in the standing crop and Simpson's index. The salt content of soil showed similar tendency on the density and the T/R ratio.

• Journal of The Geomorphological Association of Korea
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• v.24 no.1
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• pp.1-12
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• 2017

Planting trees is a very common practice in the coastal dunefields of South Korea as a way to stabilize dune landscapes and protect inland residential areas from strong winds and blown sands. On the other hand, disturbing the original foredune environment may deteriorate the ability of coastal landsto recover from coastal erosion after storms, causing a retreat of coastline. However, there is little information of this sort on the surface of forested dunefields. Airborne LiDAR or drone-based mapping is not easily applicable in such areas. In this study, we developed a digital terrain model of Dasari dunefields, Chungnam Province, based on direct topographic surveys with real-time kinematic GPS and total stations. We also analyzed previous two aerial photographs taken in 1947 and 1966, in order to detect an older landforms of the dunefields. Results suggested that there have been little changes in geomorphology of the Dasari dunefields for the last 50 years, despite continued tree plantings. Today, there are remains of U-shaped structures such as blowouts and parabolic dunes in the dunefields.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.3
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• pp.99-114
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• 2021

We examined a current status of damage in biodiversity and its causing factors in Hasidong Anin coastal dune, Gangneung-si, Gangwon province which is designated as ecological and landscape conservation area. In this study, we found that ecosystem and biodiversity have been primarily damaged by anthropogenic factors such as the construction of surrounding area, military facilities illegally dumped garbage and the expansion of windbreak forest. These factors occur to damage the landscape, ecosystem and biodiversity etc. There is a significant lack of basic data needed for preservation and restoration due to the lack of prior research and value assessment. In order to establish solutions for preservation and restoration, it is critical to collect fundamental data and implement value assessments. Therefore, further studies such as ecosystem services assessment, increasing biodiversity, spatial analysis and monitoring of various items related to coastal dunes are needed.

• Journal of The Geomorphological Association of Korea
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• v.18 no.3
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• pp.83-92
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• 2011

The properties and changes of geomorphic relief and coastal deposits were analyzed at Goreabul sand beach in Yeongdeok-gun, the largest that in east coast of Kyungsangbuk-do Province. As the result of grain size analysis, in almost season except summer, the sands mainly deposited in Goraebul sand beach because longshore current drift northward contrary to Gangwon-do east coast, and summer longshore current is weak or change direction to south ward. Sand beach mostly came form erosion owing to typoon and storm and was deposit more coarse sand in the summer, and was produced deposition actively in the fall and winter. Front side of sand dune came from deposition on sand every season by sea breeze, especially in the winter.

• Journal of Life Science
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• v.18 no.10
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• pp.1355-1359
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• 2008

Endophytic fungi predominantly inhabit grasses, and produce a variety of beneficial metabolites for plant growth, as well as help their hosts against pathogens and herbivores. Current study was focused on plant growth promoting activity of endophytic fungi inhabited in the roots of sand dune grasses. We collected 49 fungal isolates from the roots of four most common sand dune grasses and screened them for their growth promoting capacity. Results showed that 37 fungal isolates (75.5%) promoted plant height and shoot length of waito-c rice, 11 fungal isolates (22.5%) suppressed it, while 1 fungus (2%) showed no effect on the growth attributes. The fungal strain Gibberella fujikuroi, along with distilled water and Czapek broth medium, were taken as control for this experiment. It was concluded that a major proportion of endophytic fungi inhabited in the sand dune plants produce metabolites, and thus help in growth and development of the host plant.