• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.80-96
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• 2023

The expansion of human activities and road development has led to the loss and fragmentation of ecological spaces, which is a negative factor for biodiversity. In particular, urban areas where land use and land cover have rapidly changed into urbanization zones are regions where ecological spaces are lost and isolated, making it difficult for wildlife to inhabit. Furthermore, the loss and fragmentation of ecological spaces due to urbanization can have a negative impact on ecosystem services. Therefore, to enhance biodiversity and ecosystem services in urban and national land, it is necessary to establish a practical ecological axis that reflects the current status of the city. Thus, this study analyzed the connectivity of ecological spaces and forest axis that can be used for spatial planning related to urban ecological axis of local governments in Daegu and Gyeongsangbuk-do. The ecological connectivity was analyzed by dividing the Daegu-Gyeongbuk region into 31 local government units, distinguishing between forests and natural areas using land cover data. Subsequently, the study area was divided into 20,483 hexagonal grids of 1 square kilometer each, and the restoration effects for ecological fragmentation within 100 meters were spatially clustered to visualize priority restoration areas. The forest axis was derived by considering regional conditions such as land cover, building area, slope, and others to connect 1,534 forests of 100 hectares or more. The research results are expected to be used as fundamental data for spatial planning, goal setting, and the selection of restoration areas for improving ecological connectivity.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.9-18
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• 2023

Climate change affects the safety of river revetments, especially those associated with external flooding. Research on slope reinforcement has been actively conducted to enhance revetment safety. Recently, technologies for producing embankment blocks using recycled materials have been developed. However, it is essential to analyze the impact of block shapes on the flow characteristics of exclusion zones for revetment safety. Therefore, this study investigates the influence of revetment block shapes on the hydraulic characteristics of revetment surfaces through 3D numerical simulations. Three block shapes were proposed, and numerical analyses were performed by installing the blocks in an idealized river channel. FLOW-3D was used for the 3D numerical simulations, and the variations in maximum flow velocity, bed velocity beneath the revetment, and maximum shear stress were analyzed based on the shapes of the revetment blocks. The results indicate that for irregularly sized and spaced revetment blocks, such as the natural stone-type vegetation block (Block A), when connected to the revetment in an irregular manner, the changes in flow velocity in the revetment installation zone are more significant than those for Blocks B and C. It is anticipated that considering the topographical characteristics of rivers in the future will enable the design of revetment blocks with practical applicability in the field.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.2
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• pp.34-44
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• 2024

Recently, due to abnormal climate caused by climate change, natural disasters such as floods, landslides, and soil outflows are rapidly increasing. In Korea, more than 63% of the land is vulnerable to slope disasters due to the geographical characteristics of mountainous areas, and in particular, Quarry mines soil and rocks, so there is a high risk of landslides not only inside the workplace but also outside.Accordingly, this study built a DEM using UAV and aviation LiDAR for monitoring the quarry, conducted a time series change analysis, and proposed an optimal DEM construction method for monitoring the soil collection site. For DEM construction, UAV and LiDAR-based Point Cloud were built, and the ground was extracted using three algorithms: Aggressive Classification (AC), Conservative Classification (CC), and Standard Classification (SC). UAV and LiDAR-based DEM constructed according to the algorithm evaluated accuracy through comparison with digital map-based DEM.

• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.1-18
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• 2016

This study was carried out to investigate the flora of the western front (Paju-Yencheon Area) of the Civilian Control Zone. Vascular plants collected in these areas were a total of 558 taxa composing of 501 species, 3 subspecies, 48 varieties and 1 forma of 330 genera under 109 families This shows that 11% of the 4,880 vascular plant species that are known to exist in Korea is distributed in the western part of the DMZ. 1 taxa of endangered species designated by the Ministry of Environment was found: the Polygonatum stenophyllum Maxim in the edge of the military operation road from Taepung observatory to Imjin river. For the floristically specific ones of the Korean floristic zones, 3 taxa of the $5^{th}$ grade, 3 taxa of the $4^{th}$ grade, 13 taxa of the $3^{rd}$ grade, 13 taxa of the $2^{nd}$ grade and 22 taxa of the $1^{st}$ grade were found. For the endemic species of Korea, 4 taxa including Cirsium setidens (Dunn) Nakai were confirmed to be distributed mostly on the slope or the cutting area. Among the collected rare plants (11 taxa), there were 1 taxa of endangered species, 4 taxa of vulnerable species and 6 taxa of least concern species. Also, 51 taxa of naturalized plants were identified and 4 taxa of ecosystem disturbance organism designated by the Ministry of Environment were identified. The urbanization index and naturalization index for all species were estimated to be 15.89% and 9.14% respectively. Our survey is expected to be considered as primary data of biological diversity and ecological axis in the DMZ and the western part of the DMZ. According to the results of this study, it is thought to be necessary to establish policies for conservation and protection of the DMZ.

• Journal of Environmental Policy
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• v.11 no.3
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• pp.25-47
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• 2012

This research is to suggest an ecological management methods by classification of biotope type and its mapping for Tricholoma matsutake. The target area was construction site of the East Hongchun - Yangyang Highway (Yangyang section) where massive production of Tricholoma matsutakes is in place. Specifically, the 700 m long range of area around the road route, Yangyang section, which is over a total area of $19,79km^2$. The flow of this research was as follows: first studied were the characteristics of the Yangyang Tricholoma matsutakes; second, reviews on previous studies on Tricholoma matsutakes; third, the formulation of standards and processes of biotope type considering Tricholoma matsutake production; and fourth, mapping of biotope considering the production area of Tricholoma matsutake. In 24.77% of the region, slope angle measured $30{\sim}40^{\circ}C$, which is suitable for Tricholoma matsutake production. Also, 17.44% of the region had southward vegetation structures, and as for the Pinus densiflora; 26.00% had average receipts; the tree ages was $38{\pm}8.34$ years; and the average density of canopy layer was $9.55{\pm}4.89/100m^2$. The soil acidity (pH) values of 5.0 to 5.6(47.96%) > 5.6 to 7.0(42.90%) > 4.0 to 5.0(9.14%) were slightly high for Tricholoma matsutake growth; but 57.10% of the area had a soil pH of 4.0-5.6. The organic horizon (A0 layer) was $3.39{\pm}2.14cm$, and the mean depths were 4-6cm(78.03%) > 0-2cm(18.10%) > 2-4cm(3.87%). Based on the results of previous studies and field researches on the presence of vegetation (the pine dominance ratio), the topographic structure (the terrain characteristics and slopes), the receipt, the soil structure (the soil acidity and the organic layers interposed between the depths), and the vegetation density, six clusters based on the identified types of biotopes are produced in this paper. Area of distribution according to the type of biotope was Tricholoma matsutake of the potential-production (II) biotope (32.86%) > Tricholoma matsutake of the inadequate-production biotope (22.17%) > Tricholoma matsutake of the adequate (II)-production biotope (17.79%) > Tricholoma matsutake of the adequate (I)-production biotope (14.86%) > Tricholoma matsutake of the potential-production (I) biotope (9.77%) > Tricholoma matsutake of the produced biotope (2.55%).

• 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 the Korean association of regional geographers
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• v.4 no.2
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• pp.15-30
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• 1998

Physical geography is the discipline which deals with the relationship between man and natural environment. Therefore, it should be studied as the organized unity. In this paper I recognize the drainage basin as a framework outlining physical geography, describe the difference of inhabitant's life style due to the difference of natural environment in the drainage basin, and consider the meaning of drainage basin as a unit of life(and unit of regional geography). Munkyung is divided into three regions(intermontane basin region, middle mountainous region, marginal hilly region of the great basin) owing to the topographic characteristics. Subdivision in these regions is related closely to drainage network distribution, specially in intermontane basin region. And small regions have developed with the confluence point of $3{\sim}4$ order streams as the central figure. Intermontane basin region is the valley floor of Sinbuk-Soya-Kauun-Nongam stream located in the limestone region which is exposed according to Munkyung fault at its northern part. Small streams are affected strongly by the influence of the NNE-SSE or WNW-ESE tectolineament. Thus Kaeripryungro(鷄立嶺路), Saejaegil(새재길), Ewharyungro(伊火嶺路) and so on are constructed through the tectolineament. In the valley floors of small streams which flow into the intermontane basin, there are large floodplains. Floodplain in Sinbuk, Joryung, and Yangsan stream is used to paddy field or orchard, and in Nongam stream is used to paddy field or vegetable field. Hills are distributed largely in the periphery of intermontane basin. Limestone hills in Kauun and Masung basin are not continuous to the present low and flat floodplain, and most of those are used to forest land and field. On the other side. granite hills in Koyori are continuous to be used to the present floodplain, and they are used to residential area and field. In the middle mountainous region are there hilly mountains constructed in the geology of Palaeozoic Pyeongan System in northern area and Chosun System's Limestone Series in southern area, and banded gneiss and schist among Sobaeksan Gneiss Complex. In Palaeozoic Pyeongan System region are there relatively rugged mountains and ingrown meanders developed along tectolineaments. Chosun System's Limestone Series region builds up a geomorphic surface, develops various karst landforms. Mountainous area is used to field. On the other hand, especially in case of Hogye, valley bottom is wide, long, and discontinuous to slope, is used to paddy field dominantly. And schist region in Youngnam Block of Pre-Cambrian is rugged mountainous. Marginal hilly region of the great basin is hilly zone located in the margin of erosional basin(Bonghwa-Youngju-Yechon-Hamchang-Sangju). This region is lower geomorphic surface which is consisted of hills of $50{\sim}100$m height. Hills are used to field or orchard, and dissected gentle depression is used to paddy field.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.1 no.1
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• pp.3-17
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• 1998

The purposes of this study is to investigate the possibility of planting trees at space land in the riverside. The space land is for the green space. Calculating the plantable space in the representation section and the flood flowing stability of the existing banks based on the hydrological and meteorological data of the Kap-Chon riverbasin located in Tae-jon, the following results are drawn. (1) The flood discharges in each flow section are $698.7m^3/s$ in section 1, $654.6m^3/s$ in section 2, and $1353.3m^3/s$ in section 3 during 100 years recurrence interval. Because the designed-flood discharges in those sections are $1719.9m^3/s$, $2119.7m^3/s$, and $1512.8m^3/s$ respectively, safety for flood flowing is sufficient in existing banks. (2) The possible clearance for planting trees is 1.80m in section 1, 3.90m in section 2, and 0.01m in section 3. Planting clearance is enough in section 1 and 2. However, planting should be planned after estimating a rise-height due to the bridge piers, because many piers under riverine-highway are now on the construction in section 2. The section 3 does not have sufficient clearance for planting trees, but the planting is possible after getting enough flow area with slope by cutting the terrace land on the river artificially heightened. (3) In case of planting a tree 70cm diameter in $1m^2$ in section 1, the water level increases by 0.60m. Planting a tree in a $48m^2$ area increases the water level by 0.90m. Considering that plantable clearance is 1.8m in section 1, it is sufficient to flow safely. But if the trees are planted so compactly from the upper stream, expected heavy resistance is expected due to caught materials on the trees. So, trees have to be planted widely in upper streams but compactedly in lower streams. (4) The river width without changing, Kap-Chon's flow channel can be snaked in accordance with the nature law the wide terrace land in the riverside. Decreased flow area due to planting trees will be compensated by the inclination of terrace land. And, it is theoretically proved that the flood discharge is safe even though the terrace land on the river is parked similar to the nature. Planting trees in the terrace land of the Kap-chon river to the extent that flood flowing is not adversely affected, we can get the enjoyable park to citizens not spending expensive cost. It also contributes to the recovery of ecosystem, which gives the natural beauty of river and shade to citizens and becomes good natural-educational places for children.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.87-94
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• 1986

This study was performed in order to contemplate their correlations between physical and mechanical properties of the marine clays which were collected from main harbors in Korea. The results obtained are as follows: 1. Most of the soils in experimental districts consist of CH. CL. and ML. and they are considered to be still proceeding. 2. The equations of the relationship between compression index and liquid limit are as, follows: CH : $C_c=0.0137$ (LL-22.60) CL : $C_c=0.0123$ (LL-14.64) 3. The relationship between compression index and initial void ratio appears that the higher the plasticity, the easier the slope of the regression line. The equations are as follows : CH : $C_c=0.431$ ($e_o-0.504$) CH : $C_c=0.471$ ($e_o-0.235$) ML : $C_c=0.641$ ($e_o-0.393$) 4. The equations of the relationship between compression index and natural water content are as follows: CH : $C_c=0.0133$ ($W_n-28.27$) CL : $C_c=0.0225$ ($W_n-23.56$) ML : $C_c=0.0106$ ($W_n-16.42$) 5. The relationship between initial void ratio and natural water content, and compression index is highly positive correlation and the equations are as follows : CH : $C_c=0.301$ ($e_o+0.017W_n-1.05$) CL : $C_c=0.141$ ($e_o+0.0567W_n-1.054$) ML : $C_c=0.421$ ($e_o+0.0214W_n-1.121$) 6. The equations of the relationship between initial void ratio and liquid limit, and compression index are as follows : CH : $C_c=0.36$ ($e_o+0.08LL-0.819$) CL : $C_c=0.269$ ($e_o+0.026LL-0.929$) 7. The cohesion of marine clays is no concerned with the increment of depth. The equations of relationship between cohesion and unconfined compression strength are as follows. CH : qu=1.896C+0.0107 CL : qu=1.849C+0.04.

• Korean Journal of Heritage: History & Science
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• v.44 no.2
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• pp.4-25
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• 2011

This study was performed in 2010 to examine the flora and vegetation structure and chemical characteristics of soil in the growing community of Abeliophyllum distichum, located in the Byeonsanbando National Park. This Abeliophyllum distichum community has more individual numbers in Cheongrim-ni and Jungkye-ri, Byeonsan-myeon, and Buan-gun area, which is designated as a Natural Monument (No. 370), and also where the habitat conditions for Abeliophyllum distichum is more favorable. The authors recorded 100 taxa with 45 families, 82 genus, 93 species, 4 varieties, and 3 forms. Among them, species such as Abeliophyllum distichum (critically endangered), Asarum maculatum (near threatened) and Chionanthus retusa (near threatened), which are categorized as rare plants, were recorded. According to the list of Korean endemic plants, 4 taxa, particularly Philadelphus schrenckii, Abeliophyllum distichum, Weigela subsessilis, and Lonicera subsessili, were recorded. The community of Abeliophyllum distichum is located in the northwest slope of Baekcheon watershed and the community is comprised of healthy soil. The community structure was classified into three: the Castanea crenata community, Zelkova serrata community, and Quercus serrata community. The Castanea crenata community is composed of the Cornus walteri, Platycarya strobilacea, Zelkova serrata, Rhamnella frangulioides, arranged in terms of importance percentage. The Zelkova serrata community is composed of Celtis sinensis, Quercus aliena, Styrax japonica, and Acer pseudo-sieboldianum, also according to importance percentage. As for the Quercus serrata community, it is composed of Quercus variabilis, Castanea crenata, and Prunus sargentii, also arranged in terms of importance percentage. The importance percentage of Abeliophyllum distichum is 6.6% in the Castanea crenata community, 5.6% in the Zelkova serrata community and 5.1% in the Quercus serrata community. Moreover, in order of chemical characteristics of soil pH, electrical conductivity, available phosphoric, organic matter, and exchangeable cation (K, Ca, Mg) are analyzed. The No. 3 site was relatively higher than other districts of the same chemical characteristics of soil.