• Journal of Korea Water Resources Association
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• v.56 no.1
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• pp.23-34
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• 2023

This study analyzed the bed load transport and channel change on the vegetation zone through laboratory experiments and numerical simulations. To examine the effect of vegetation zone in the laboratory experiment, artificial vegetation zones made of acrylic sticks were installed in the experimental channel, and discharge conditions were adjusted to examine the bed load transport and channel change in the vegetation zone. Next, numerical simulations were performed by applying the same conditions as those of the laboratory experiment to the Nays2D model, a two-dimensional numerical model, and the applicability of the numerical model was examined by comparing the results with the results of the laboratory experiment. Finally, by applying a numerical model, the bed load transport and channel change according to the change in vegetation density were examined. As a result of examining the bed load transport and channel change in the vegetation zone according to the discharge condition change by applying the laboratory experiment and the numerical model, the results of the two application methods were similar. As the discharge increased, bed load from the upper stream was deposited inside the vegetation zone. On the other hand, on the other side of the vegetation zone, the flow was concentrated and erosion occurred. Also, the range of erosion increased in the downstream direction. As a result of examining the bed load transport and channel change according to the change in vegetation density, as the vegetation density increased, the bed load from the upper stream was deposited inside the vegetation zone. On the other hand, due to the increase in vegetation density, the flow was concentrated to the opposite side of the vegetation zone, erosion occurred.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.29-39
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• 2009

Research was initiated to investigate a vegetation characteristics of the winter season by seeding periods. 3 seeding periods (Mid-December seeding plot, Late January seeding plot and Early March seeding plot) and 3 zones (the top zone, the middle zone and the bottom zone) in each plot were treated with 3 replications on the experimented slope. Data such as vegetation coverage (%), soil hardness (MPa), temperature ($^{\circ}C$) and moisture (%) content were analyzed. The vegetation coverage was high in Early March seeding plot, medium in Mid-December, and low in Late January seeding plot. Early March seeding plot was effective in moisture content, soil hardness, and temperature for the growth of vegetation when compared to Late January seeding plot and Mid-December seeding plot. From the standpoint of coverage ratio of plant species, the coverage of Dianthus sinensis and Albizzia julibrissin were high in the Late January seeding plot whereas the coverage of Lotus corniculatus and Cool-season turfgrass were high in Early March seeding plot. These results indicated that the high vegetation coverage of Dianthus sinensis and Albizzia julibrissin in Early March seeding plot was caused by scarification during winter season. There was no difference observed in plant height regardless of seeding periods except in early surveying time of May and June after seeding. As far as each zone of the plot was concerned, the vegetation coverage was high. in the bottom zone, medium in the middle zone and low in the top zone. The bottom area of the experimented slope was high in moisture content when compared to the middle zone and the top zone.

• Journal of Ecology and Environment
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• v.34 no.3
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• pp.259-267
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• 2011

A pollen analytical study of sediment sequences collected from Yongneup moor (sampling point: $38^{\circ}$12'57.4" N, $120^{\circ}$7'30.2" E) was conducted to understand the vegetation history in the mountainous region of the central Korean peninsula. Carbon dating was carried out to measure five successive samples obtained from the bottom at a depth of 180 cm to the surface. The Yongneup moor sediment revealed four main local pollen zones; that is, four past vegetation phases as follows: Local pollen zone I: Quercus-Pinus zone; estimated age, 5,900-4,800 calibrated years (cal) before present (BP); vegetation type, cool-temperate central/montane deciduous broad-leaved forest. Local pollen zone II: Pinus-Abies-Quercus zone; estimated age, 4,800-3,400 cal BP; vegetation type, cool-temperate northern/alti-montane mixed coniferous and deciduous broad-leaved forest. Local pollen zone III: Quercus-Pinus-Abies zone; estimated age, 3,400-400 cal BP; vegetation type: cool-temperate central/montane deciduous broad-leaved forest. Local pollen zone IV: Pinus-Quercus zone; estimated age, 400-present cal BP; vegetation type, cool-temperate central/montane mixed deciduous broad-leaved and coniferous forest. It was confirmed that subalpine coniferous forests had expanded to the mountainous region of the central Korean peninsula during the period from 4,800-3,400 cal BP and thereafter deciduous forests dominated by Q. mongolica were established. Notably, secondary forests dominated by P. densiflora developed in the lower part of the mountainous region of the central Korean peninsula about 400 cal BP due to human interference.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.1
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• pp.41-51
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• 1990

This study was executed to investigate the vegetation structure and to propose the vegetation management proposals of the Sansung Nature Park at Cheonju City and the results were as fellows. 1. A damage of vegetation and soil surface around the Namgosa was taken place up to 100m by picnic 2. Pinus rigida forest covered 36.1% of the total area(152.6ha) and total afforested vegetation covered 43.5%, respectively. P. denstflora comm. covered 28.4% arid Carpinus laxiflora Comm. as a climax vegetation in temerate zone covered 0.3%, respectively. 3. 6, 7 and 8 of the degree of human disturbance of vegetation covered 45.3%, 26.6% and 21.4%, respectively and resulted in low quality of naturalness. 4. Physical and chemical properties of soil were pour at high elevation and were poor severely in and around the Namgosa due to human disturbance. 5. Plant community were under rapid succession and had unvalanced structure and heterogeneous composition of species. Rapid vegetational succession from Pinus densiflora and Pf. rigida to Carpinus laxifora, Quercus spp. and Robinina pseudo-acacia were taken place.6. The speeies of Raunkiaer's frequency class I as of high frequency class were Pinus dunsiflora, Carpinus alxiflora, Quercus mmongolica, Sorbus alnifolia, Prunrs sargintii, Rhododendron yedoense, Stephanandra incisa and Lespedeza maxinowiczii. 7. Vegetational management proposals were made for three vegetation zones ; Historic landscape restoration and preservation zone, Afforested vegetation zone, Native vegetation conservation zone and recommanded native species for landcape planting.

• Journal of Ocean Engineering and Technology
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• v.36 no.5
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• pp.326-339
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• 2022

Recently, not only Korea but also the world has been suffering from problems related to coastal erosion. The hard defense method has been primarily used as a countermeasure against erosion. However, this method is expensive and has environmental implications. Hence, interest in other alternative methods, such as the eco-friendly vegetation method, is increasing. In this study, we aim to analyze the hydraulic characteristic of submerged rigid vegetation according to the cross-sectional change through a hydraulic experiment and numerical simulation. From the hydraulic experiment, the reflection coefficient, transmission coefficient, and energy dissipation coefficient were analyzed according to the density, width, and multi-row arrangement of the vegetation zone. From numerical simulations, the flow field, vorticity distribution, turbulence distribution, and wave distribution around the vegetation zone were analyzed according to the crest depth, width, density, and multi-row arrangement distance of the vegetation zone. The hydraulic experiment results suggest that the transmission coefficient decreased as the density and width of the vegetation zone increased, and the multi-row arrangement condition did not affect the hydraulic characteristics significantly. Moreover, the numerical simulations showed that as the crest depth decreased, the width and density of vegetation increased along with vorticity and turbulence intensity, resulting in increased wave height attenuation performance. Additionally, there was no significant difference in vorticity, turbulence intensity, and wave height attenuation performance based on the multi-row arrangement distance. Overall, in the case of submerged rigid vegetation, the wave energy attenuation performance increased as the density and width of the vegetation zone increased and crest depth decreased. However, the multi-row arrangement condition did not affect the wave energy attenuation performance significantly.

• The Korean Journal of Quaternary Research
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• v.13 no.1
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• pp.1-23
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• 1999

A palynological investigation of the Annyeong-ri, Hwasung-gun Gyeonggi-do, in where Yung-Nung and Gun-Nung are located, was carried out for the first time. From the pollen analysis, two pollen zones are established: Pollen Zone I : Ainus-Quercus-Pinus and Pollen Zone Ⅱ : Pinus. Pollen Zone I is characterized by Mixed coniferous and deciduous broadleaved vegetation during about 3,500 yr. B.P.-2,000 yr. B.P., while after 2,000 yr. B.P. Pollen Zone Ⅱ appears to be Coniferous vegetation and Evergreen broadleaved vegetation. The former reflects there was a lowland fluvio-lacustrine environment before fully lacustrine one which represents the latter. Pollen analysis indicates the vegetation before 2,000 yr. B.P. was controled by environmental factor such as climate conditions, whereas after that time vegetation was strongly effected by human's impact. It is concluded that pollen analysis is useful to find out the relationship between vegetation history and man's interference. In addition freshwater algae play to tell the lake environments.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.3
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• pp.224-235
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• 2014

Changes in the interactions among incident ocean water waves, coastal debris (marine debris), and the back vegetation zone line on a natural sandy beach on the island of Jinu-do in the Nakdong river estuary were investigated. The study involved a cross-sectional field survey of the beach, numerical modeling of incident ocean water waves, field observations of the distribution of coastal debris, and vegetation zone line tracking using GPS. The conclusions of this study can be summarized as follows: (1) The ground level of the swash zone (sandy beach) on Jinu-do is rising, and the vegetation zone line, which is the boundary of the coastal sand dunes, shows a tendency to move forward toward the open sea. The vegetation zone line is developing particularly strongly in the offshore direction in areas where the ground level is elevated by more than 1.5 m. (2) The spatial distributions of incident waves differed due to variations in the water depth at the front of the beach, and the wave run-up in the swash zone also displayed complex spatial variations. With a large wave run-up, coastal debris may reach the vegetation zone line, but if the run-up is smaller, coastal debris is more likely to deposit in the form of an independent island on the beach. The deposited coastal debris can then become a factor determining which vegetation zone line advances or retreats. Finally, based on the results of this investigation, a schematic concept of the mechanisms of interaction between the coastal debris and the coastal vegetation zone line due to wave action was derived.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.5
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• pp.39-47
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• 2000

This study is to investigate the conditions closely related to the establishment of vegetation in the riparian zone: the soil condition, an important factor along with climate and light. Especially, the soil structure of the microtopographical formations in the specific area known as the riparian microtopographical zone investigated. In addition, the effect of the riparian microtopographical features on the ground water level, soil moisture content, and vegetation was studied. The results of this study are as follows; 1) At all sample sites, below the sand layer, a gravel layer is always present. This is the result of past floods. 2) Although Salix koreensis experiences frequent disturbances such as increase in river level and floods, this vegetation establishes itself in the most secure are in the microtopographical zone. 3) The growth of Phragmites japonica is closely related to the underground water level. 4) It is clear that Miscanthus sacchariflorus grows concentrated in dry areas. 5) The soil accumulation conditions differ according to the soil moisture content of each microtopgraphical feature. Accordingly, the moisture content of the soil is clearly different within the microtopographical zone. The continuous and long-term investigation and research on the relation of riparian reproduction and the relevance with location surrounding factors are necessary in the future.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.153-159
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• 2011

Vegetative land cover is an important variable many Earth system process, general circulation and carbon exchange model requires vegetative cover as boundary layer necessary to run model. The purpose of this study is to detect and to understand land surface change. To monitor changes of East Asia vegetation, we used NDVI 10-day MVC data derived from SPOT VEGETATION during 12 years from 1999 to 2010. Finally, according to the land cover of classified class, we performed analysis for dynamic zone(positive change zone and negative change zone), static zone in 1999, 2010. Therefore, land covers corresponding to each class have appeared change by 2010. Land cover change was confirmed by analyzing data during 12 years which appeared vegetation change of surrounding the actual desert area to east.

• The Korean Journal of Ecology
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• v.21 no.5_2
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• pp.501-518
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• 1998

Mt. Paektu(2,749.6m)m the biggest mountain in Northeast Asia, located on the border line of Korea and China is characterized as an aspite with broad gentle mountain area and rich biota. however, it seems that the study of forest vegetational feature or vegetation zones in the whole area of this mountain is not yet sufficient in spite of contribution by many investigators. in this paper thermal climatic approach was carried out for the determination of vegetation zones of the mountain with the meteorological data of four stations including Cheonjj and various vegetational data. the application of Warmth Index and/or coldness Index(Kira 1977) for the determination of forest vegetation boundary was useful also here, and their boundaries largely coincided with those of thermal indicies obtained in the Korean Peninsula(Yim and Kira, 1975), including the lapse rate of air temperature along increasing elevation. However, in the mountain the boundary of vegetation zones in not clear like those of mountains in Korea. It may be due so the topographic differences between this area and the Korean Peninsula. Besides, the broad ecotones between different vegetations in this area support the vegetation continum concept rather than the unit concept, and the limit of timber line or tree line reflects various hypothesis(Steven and fox 1991). Therefore, for the explantion of vegetation zone of this area should be considered topography or soil condition, for example, as known the hierachy of ecological units (zonobiomes, orobiomes and pedobiomes, Walter, 1973).