• Journal of Korea Water Resources Association
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• v.42 no.2
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• pp.141-148
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• 2009

Each river in each country has peculiar channel characteristics at every section. Korea consists of mountains at the rate of 70%. Due to this, the sections that display unique channel form are scattered. One of the typical features is the narrow pass of channel section that presents in the process of the generation of alluvial channel and deformation channel. Around as this narrow pass of channel, it often comes to be regular flood disaster section. Regardless of this situation, investigations and plans that reflect channel characteristics at the narrow pass of channel have been wholly wanting until now. In accordance with this, we have investigated and analysed hydraulic significance and channel form of the narrow pass of channel in Seonsan in this study. The study has found real minute classification of sediment phenomenon at river bed of low flow channel on investigation section which is sand-bed river, but it was vaguely difficult to conclude that classification of sediment arises from explicit natural force. We were able to assume that the phenomenon comes from gentle bed slope, supply of river bed materials which is nearly uniformity. However, classification of sediment would come from collecting an aggregate rather than natural force. And we found that compound cross section conversion has been developing dramatically with channel form of movable bed section referring to movement which was active before at drainage district of the narrow pass of channel. With this, we could find the phenomenon that river width of low flow channel diminished largely. This kind of situation implies that it may cause compound section weighting, flood dimension decreasing, revetment at low flow channel or the local scour at bottom of levee when extraordinary flood occurs.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.761-778
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• 2017

The need of the underground space for the infrastructures in urban area is increasing, and especially the demand for shallow tunnels increased drastically. It is very important that the shallow tunnel in the urban area should fulfill not only its own safety conditions but also the safety condition for the adjacent structures and the surrounding sub-structure. Most of the studies on the behavior of shallow tunnels concentrated only on their behaviors due to the local deformation of the tunnel, such as tunnel crown or tunnel sidewall. However, few studies have been performed for the behavior of the shallow tunnel due to the deformation of the entire tunnel. Therefore, in this study the behavior of the surrounding ground and the stability caused by deformation of the whole tunnel were studied. For that purpose, model tests were performed for the various ground surface slopes and the cover depth of the tunnel. The model tunnel (width 300 mm, height 200 mm) could be simulationally deformed in the vertical and horizontal direction. The model ground was built by using carbon rods of three types (4 mm, 6 mm, 8 mm), in various surface slopes and cover depth of the tunnel. The subsidence of ground surface, the load on the tunnel crown and the sidewall, and the transferred load near tunnel were measured. As results, the ground surface subsided above the tunnel, and its amount decreased as the distance from the tunnel increased. The influence of a tunnel ceased in a certain distance from the tunnel. At the inclined ground surface, the wider subsidence has been occurred. The loads on the crown and the sidewall were clearly visible, but there was no effect of the surface slope at a certain depth. The load transfer on the adjacent ground was larger when the cover depth (on the horizontal surface) was lager. The higher the level (on the inclined surface), the wider and smaller it appeared. On the shallow tunnel under inclined surface, the transfer of the ambient load on the tunnel sidewall (low side) was clearly visible.

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.63-69
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• 1986

In general, the snow injury in forestry is an unusual disaster. The degree of snow injury varies greatly depending on stand density and the local topography. This study was conducted to investigate the snow injury in analyzing the demaged by snow-fall in Jinju, Gyeongsangnamdo. The results obtained were summarized as follow; Among 466 total damaged trees, 425 trees were broken and 41 trees were uprooted, the ratio of damage were 5.22%, 2.49%, 0.92% and 0.2% for Pinus densiflora, Pinus thunbergii, Pinus rigida, Alnus hirsuta respectively. The 95% of the damage trees were in the range of 3 to 11 m for height and in the range of 3 to 20 cm for D. B. H.. The directions of the damage trees had a large influence by direction of the wind, but they shown at high tendency to aspect of the slope relatively. The 82% of the damaged trees ranged from 11 to 24 age. The ratio of broken height ($H_B/H$) indicated that the damage was most frequent in the part of stem as 24%, 45%, 31% in the part of the root collar (0.1), stem (0.2-0.4), crown (0.5-1.0) respectively. In general, trees with stem-form coefficient ($H_B/D$) over 0.7-0.8 are apt to suffer by snow damage. The average of stem-form coefficient of trees in this area was 1.06. Therefore, the ratio of damage was high tendency as 3.14%. These results indicate that it is necessary to apply pertinent tending which will increase in resistance of snow damage. As avalanches from the flank of soil erosion rise in an importance matter in present, it should also be considered to measures for prevention and restoration.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.38 no.4
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• pp.74-85
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• 2020

Darangnon in Gachon Village, Namhae-gun, Gyeongsangnam-do, is the first designated environment among Korea's industrial-based historical and cultural sites and is still the only one that involves agricultural activities. Although the stonework, which is the infrastructure environment here, has limitations that inevitably lead to natural and artificial deformation due to its nature, there has been no research to consider the situation so far. As of the end of May 2020, this study investigated and analyzed the damage in the sub-area of the survey, which is approximately 30% of the scope of the designation of the scenic spot, from a quantitative and qualitative perspective. As a result of the study, the state of loss, which reveals the physical damage of the arctic rice paddy stone retaining wall in the environment under investigation, was particularly serious around the coast, in the northern area with high slopes, and near tourist information centers and parking lots. On the other hand, the qualitative aspect of the damage to the stonework was noticeable in the repair of heterogeneous materials on the stone retaining wall adjacent to the village and parking lot, and the landscape damage caused by the cladding of plants was found in an environment far away from the residence. In addition, natural environmental factors such as slopes, elevations, and soil showed a close relationship with the degree of physical damage of the stone retaining wall, the higher the slope, the higher the elevation, and the better the soil drainage, the greater the impact. These results suggest that humanities environmental factors such as cultivation activities and management entities have important factors in the physical damage and management of stone retaining wall. Therefore, it is deemed essential to find management measures with local residents along with improving the agricultural environment, such as securing agricultural water and soil improvement, for the preservation of tuna paddies and stone retaining wall in the future.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.3
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• pp.21-36
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• 2023

As a solution to environmental issues, such as climate change response, the carbon neutrality strategy, urban heat islands, fine dust, and biodiversity enhancement, the value of urban green spaces and trees are becoming important, and various studies dealing with the effects of trees for environmental improvement are being conducted. This study comprehensively considers the preceding studies on planting tree species, planting structure, planting density, and planting base to propose a direction for the planting renewal of green areas in urban parks and applies the findings to a renewal plan to improve the urban environment through landscaping trees. A field survey was conducted on the planting status of Seoul Children's Grand Park, a large-scale neighborhood park in Seoul, and based on the survey data, a planting function evaluation was conducted, and areas needing improvement in planting function were identified. The planting function evaluation was carried out considering the park function setting, planting concept according to spatial function, and planting status. As a result of the study, the direction of planting renewal according to functional change was derived for each stage of planting function evaluation. Increasing the green area ratio is a priority in setting up park functions, but user convenience should also be considered. As a concept of planting, visual landscape planting involves planting species with beautiful tree shapes, high carbon absorption, and fine dust reduction effects. Ecological landscape planting should create a multi-layered planting site on a slope. Buffer planting should be created as multi-layered forests to improve carbon absorption and fine dust reduction effects. Green planting should consist of broad-leaved trees and herbaceous layers and aim for the natural planting of herbaceous species. For plant species, species with high urban environment improvement effects, local native species, and wild bird preferred species should be selected. As for the planting structure, landscape planting sites and green planting sites should be composed of trees, shrubs, and trees and herbaceous layers that emphasize ecology or require multi-layered buffer functions. A higher standard is applied based on the planting interval for planting density. Installing a rainwater recycling facility and using soil loam for the planting base improves performance. The results of this study are meaningful in that they can be applied to derive areas needing functional improvement by performing planting function evaluation when planning planting renewal of aging urban parks and can suggest renewal directions that reflect the paradigm of functional change of created green areas.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.29 no.2
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• pp.77-100
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• 2024

Circulation, tides, currents, harmful algal blooms, water quality, and hypoxic conditions in Jinhae-Masan Bay have been extensively studied. However, these previous studies primarily focused on short-term variations, and there was limited detailed investigation into the physical mechanisms responsible for ocean circulation in the bays. Oceanic processes in the bays, such as pollutant dispersal, changes on a seasonal time scale. Therefore, this study aimed to understand how the circulation in Jinhae-Masan Bay varies seasonally and to examine the effects of tides, winds, and river discharges on regional ocean circulation. To achieve this, a three-dimensional ocean circulation model was used to simulate circulation patterns from 2016 to 2018, and sensitivity experiments were conducted. This study reveals that convective estuarine circulation develops in Jinhae and Masan Bays, characterized by the inflow of deep oceanic water from the Korea Strait through Gadeoksudo, while surface water flows outward. This deep water intrusion divides into northward and westward branches. In this study, the volume transport was calculated along the direction of bottom channels in each region. The meridional water exchange in the eastern region of Jinhae Bay is 2.3 times greater in winter and 1.4 times greater in summer compared to that of zonal exchange in the western region. In the western region of Jinhae Bay, the circulation pattern varies significantly by season due to changes in the balance of forces. During winter, surface currents flow southward and bottom currents flow northward, strengthening the north-south convective circulation due to the combined effects of northwesterly winds and the slope of the sea surface. In contrast, during summer, southwesterly winds cause surface seawater to flow eastward, and the elevated sea surface in the southeastern part enhances northward barotropic pressure gradient intensifying the eastward surface flow. The density gradient and southward baroclinic pressure gradient increase in the lower layer, causing a strong westward inflow of seawater from Gadeoksudo, enhancing the zonal convective circulation by 26% compared to winter. The convective circulation in the western Jinhae Bay is significantly influenced by both tidal current and wind during both winter and summer. In the eastern Jinhae Bay and Masan Bay, surface water flows outward to the open sea in all seasons, while bottom water flows inward, demonstrating a typical convective estuarine circulation. In winter, the contributions of wind and freshwater influx are significant, while in summer, the influence of mixing by tidal currents plays a major role in the north-south convective circulation. In the eastern Jinhae Bay, tidally driven residual circulation patterns, influenced by the local topography, are distinct. The study results are expected to enhance our understanding of pollutant dispersion, summer hypoxic events, and the abundance of red tide organisms in these bays.