• Journal of Conservation Science
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• v.18 s.18
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• pp.33-50
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• 2006

Around Yeongsan river basin, there are Yeongkwang Gundong, Muan Inpyeong Tombs, Muu Gusan-ri Tombs and Hampyeong Guksan remain from which a lot of iron artifacts were excavated. Among them, 6 iron artifacts were chosen, and their microstructures were analyzed. As a result, Iron artifacts were produced sponge iron by the low temperature reduction process and a part of microstructure have the possibility that steel made by decarburizing. And also, by tempering the parts which need high strength, the iron artifacts had high strength and by distributing the weakness of the tempered structure to the nearby untempered parts, their breaking was prevented and they had the durability. These skills were used then. Especially these skills were found to be used in the 2nd century by high skilled people because an iron axe excavated at Yeongkwang Gundong of 2nd century by the historical record showed that the skill was used. Also microstructures were found to show the possibility that the iron technology was inherited to the late 5th century. When producing iron artifacts made of sponge iron containing small amount of carbon, that was made by the production process repeating molding, carburizing, heat treatment and hammering.

• The Korean Journal of Ecology
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• v.26 no.5
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• pp.255-261
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• 2003

To analyze ecological characteristics of the Ulmus pumila community, an on-the-spot survey was conducted in August, 1998 in the Dong River, Gangwon-do, South Korea. The Ulmus pumila community is partially distributed in Dong River's midstream and upper stream. Topographical characteristics of this community are significant in the point bar or sandbank of the river. The community is classified into two types, disturbed and non-disturbed types, by the effect of flooding. The Ulmus pumila community (bush forests of Siberian elms) is a representative community which forms riparian forests, but its distribution is rare in South Korea. Only in Dong River is the Ulmus pumila distributed enough to form a community, and none is known that is lager than this community in South Korea. The non-disturbance type progresses more homogeneously than the disturbance type because it is formed on riverside banks where it is affected less by flooding. We concluded that the Ulmus pumila community in this study area has characteristics of riparian forests. In South Korea, Ulmus pumila community can be regarded as important element of vegetation landscape constituting riparian forests. Specifically, these riparian forests are evaluated as high in conservation value due to their being formed spontaneously. Moreover, Dong River is regarded as the southern limit of Ulmus pumila, which has a northern origin. The species or community needs continuous interests and conservation countermeasures because there are limitations in its spread of distribution by natural or artificial efforts.

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.787-795
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• 2011

Extreme water events such as heavy rainfalls due to recent climate change are continually increasing and their scale has also shown an increasing trend. To overcome these natural disasters, this policy study suggests securing lateral river space as an effective method for extreme flood. To support the importance of restoration and expansion of lateral river space, Gumi upstream region of the Nakdong River basin was chosen as a target area and flood reduction analysis of the washland by using LISFLOOD model have been examined. The 500-year frequency flood was simulated for the estimation of possibly occurable flood level and it turns out that the secured lateral river space on the selected site effectively lowers about 0.53 m flood level and reduces the flood damage of the city on the lower reaches of the river. In addition, based on this result, multilateral river space securing plans were compared, and conservation easement and natural disaster insurance were suggested for sustainable and cost-effective alternatives. The costs of land purchase and conservation easement for securing the river space were also compared.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.400-410
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• 2015

Juniperus chinensis (Cupressaceae) is a valuable woody plant resource, but this rare plant is only distributed in restricted regions in Korea. In this study, we surveyed the geographic distribution regions, variation of sex ratio and the dynamics of natural populations of J. chinensis. in order to establish conservation strategies for the sustainable conservation of this important resource tree. The 17 natural populations of J. chinensis are restrictively distributed in the shore cliffs of (1) Ulleungdo island, (2) Gyeongju-si to Gangneung-si of the eastern coast, the riverside cliff along (3) Donggang-river of Jungsun-gun and Pyeongchang-gun and (4) branch of Nakdonggang-river in Uiseong-gun. The populations in Ulleungdo island showed continuous population distribution of over 200 individuals, but populations in other regions had discontinuous population distribution of under 200. The population of J. chinensis surveyed in Korea was estimated in ca. 3,200 individuals. The sex ratio (male/female) among populations of J. chinensis was diverse with variation from 0.46~1.67 range, but showed no significance. The sex ratio of the total individuals by species level was 0.74, and the percentage of female tree was significantly higher than the male. The results of dynamics analysis within population among regions showed that seedlings and saplings of J. chinensis in three regions surveyed were continuously regenerating. The distribution of DBH class showed a stable population structure of inverse J shape graph, but fragmentation and decrease in populations because of invading broad-leaved shrubs and trees from the surroundings were concerned. Further studies, and in situ and ex situ conservation strategies for the sustainable conservation on natural populations of this rare resources woody plant, J. chinensis in Korea are recommended.

• Journal of Conservation Science
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• v.32 no.3
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• pp.395-402
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• 2016

The impact of a large water control project on surrounding environment(temperature and relative humidity, precipitation, wind speed, present weather and visibility) was monitored. The survey have targeted on Silleuksa temple which is located in the waterside. The number of foggy days emerged as an environmental factor that can cause damage to cultural heritage. Under construction of weir since 2011, monthly relative humidity of Yeoju and Icheon was dropped to 9.6%. It depends on decrease in the number of raining days and precipitation of each year. Silleuksa temple is contiguous to Namhan River and only 100 m away from the waterside. Average wind speed is 0.5 m/s. Silleuksa has a site environmental factors which is often foggy. The number of foggy days of Silleuksa temple declined to 53 days soon after weir's completion. In case of fog, relative humidity of outside was higher than that of outside and inside of Josadang Shrine. Relative humidity difference of outside and inside of Josadang Shrine was 5.4% on average. Relative humidity of the number of foggy days is 6.3% higher on average than that of fine days. The width and dimensions of Namhan River increased by 1.45 times after weir's construction. It can change the number of foggy days. A long-term monitoring is positively necessary on fog occurrence and relative humidity.

• Journal of Environmental Impact Assessment
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• v.22 no.5
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• pp.467-479
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• 2013

This study was conducted to find out characterization of spatial distribution of birds observed in river areas. Our bird survey was carried out 4 times at 31 sites from January to September in 2011. A total of 1,609 accumulated individuals belonging to 59 species, 28 families and 11 orders were observed. In the result of spatial autocorrelation analysis using the richness index of the maximum counts of each sites, we confirmed that the distribution of birds in Namdaecheon river was clustered and the tendency of spatial autocorrelation was apparent. The area of each sites within a 200m radius was classified in four biotope categories such as agricultural land, forest, residential area and water area, and the spatial autocorrelation was analysed about four types. In the result of spatial autocorrelation analysis for four biotope categories, all types were showed the positive spatial autocorrelation, but the type of water area was higher than other types. The positive correlation was found between the water area and water birds in statistical significance. However, the forest birds had non-significance values. Therefore, it is appropriate to focus on water birds except for forest birds, when researches of bird distribution in river ecosystem is conducted. The number of bird species and individuals increased as the riverside of water area was to widen. Thus, if the areas of riverside offering the feeding and roosting area increase, it will be accommodated many birds. Also, the areas of riverside should be maintained naturally because it is an important habitats of birds. Our study area is on the outskirts the city of higher rates of forest and agricultural land, it may be unreasonable to apply our results to the whole rivers. If the research about the river flowing around the city will be conducted, it is expected to be useful to the relation study area such as ecological river's restoration.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.5
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• pp.56-63
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• 2007

This study used the nearest feature model to connect forest patches within the western Geum River Basin. Due to many different forest patch sizes, 3 alternative methods were tested to determine the best way to establish an ecological network with forest patches. Alternative 1 used all forest patches to determine whether patches were large enough. Alternative 2 used forest patches over 10 ha in size. Alternative 3 used natural conservation indices to select forest patches containing better qualities in the natural conservation level. As a result 635 out of 724 patches of over 10 ha were selected for comparison. Alternative 1 showed that forest patches of less than 10 ha were outliers interrupting the establishment of the ecological network. They generated an unnecessary ecological network to link core areas to comparison features. The ecological network was improved by using forest patches greater than 10 ha in size(Alternative 2). Each comparison feature was much more hierarchically connected to core areas in Alternative 2 than in Alternative 1. Forest patches filtered by natural conservation indices were useful for obtaining the best ecological network. Alternative 3 clearly showed the connections in the ecological network between core areas and forest.

• Ecology and Resilient Infrastructure
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• v.9 no.2
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• pp.124-129
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• 2022

Urban river have been a key pillar in citizens' lives through the healthy urban environment of ecological nature along with the function of this dimension. On the other hand, conflicts are occurring in terms of conservation and use of rivers in the region along with the expansion of infrastructure due to urban densification. Appropriate agreement and coordination are needed for sustainable streams. This study aims to analyze various opinions through public discussion of residents' proposals through the resident participation cooperation budget. User awareness surveys and expert interviews were conducted on six rivers in Eunpyeong-gu. Through this, stable and sustainable preservation of local and small rivers and appropriate and balanced use measures were proposed.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.3 no.1
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• pp.1-6
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• 2022

Among the 13 species of otters in the world, only one Eurasian otter (Lutra lutra) is found in South Korea. In the Korean Peninsula, otter pelts were historically valuable and expensive commodities used for international trade, and otters have long been poached as hunting animals. Recent rapid economic development in South Korea has increased habitat fragmentation and loss, creating a continuing threat to the natural environment. Otters live only in the area of rivers and streams as a family group and are territorial (linear habitat). Due to these limited conditions of otter habitat, the population size of otter is lower than that of onshore mammals. According to recent research, DNA analyses using microsatellite markers have shown that only approximately 7-21 otter individuals inhabit river systems for a length of 50-230 km. Korea's urban streams are associated with many threats that hinder otters from inhabiting them. Many areas around the urban streams are surrounded by high concrete riverbanks, and the risk of roadkill is also high. Nevertheless, ecological restoration projects in the urban rivers will contribute greatly to the stable inhabitation of otters. Detailed otter conservation strategies, such as the elimination of threat factors, improvement of habitat environment, and restoration of food resources and shelter, will provide a positive restoration effect on otter and river ecosystems as well.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.4
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• pp.115-124
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• 2013

This study was conducted to make a biotop planning and construct 3 types of biotop by each site conditions. Three sites of different types in ecological and scenery conservation area of the Dong-gang river were selected by expert brain-storming process and constructed terrestrial biotops and aquatic biotops. Targets of 3 sites were set up such as constructing a habitat for Kaloula borealis and an ecological education place, building a terrestrial biotopes and monitoring the natural vegetation succession, and constructing a habitat for Luciola unmunsana Doi. The study results can be applied hereafter to ecological restoration projects, after construction of habitat, the priority should be prepare measures of monitoring and maintenance, hereafter continuous study on ecological restoration should be performed actively through construction of biotope and wild animals and plants habitat.