• Journal of Environmental Science International
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• v.23 no.8
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• pp.1523-1536
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• 2014

Restoration is the process of reducing or reversing damage to an ecosystem so that it can function in its original manner. However, many restoration programs do not achieve this. In the Nakdong Estuary, the largest migratory nesting site in the center of the East Asian-Australasian flyway, an estuarine barrage was constructed in the 1980s that required site restoration following its completion in 1987 and the expansion of several large industrial complexes(Noksan and Jangrim) and a residential development(Myeongji). The goal of the restoration was to restore the function of the wetland to its pre-disturbance state. To achieve this, a restoration program was designed consisting of three stages. The first stage(1993-1995), saw the construction of three artificial wetlands(Shinhori, Daemadeung, and Eulsuk), the second(2003-2005) involved the dredging and returning of farmed lands to their natural state, and the third(2008-2012) focused on the rehabilitation and vegetation development of the wetlands. However, the project has not achieved all of the desired goals, and it is an example of the lapses in ecological restoration following anthropogenic disturbance. Issues that resulted in an incomplete restoration included the timing of the stages, noncompliance with the restoration plan, not directly monitoring the restoration or continuing the monitoring following completion of the development project, and the political subversion of the restoration plan. For the success of the restoration plan, it is necessary to avoid mistakes such as inconsistent monitoring, unequal levels of stakeholder involvement, and political interference.

• Journal of environmental and Sanitary engineering
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• v.15 no.2
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• pp.34-40
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• 2000

In the tungsten industry, molybdenum wire which used as the center supporter for coil shape tungsten wire was removed. Nitric acid dissolution method which used prevalently up to the present, takes nitric acid as major component and use noxious material such as sulfuric acid and hydrochloric acid remove molybdenum wire which used as center supporter by dissolve selectively within the range of no damage on tungsten wire. Mixed acid waste water occurred to the process were difficult to be decomposed by the conventional methords. This mixed acid waste water was treated by ozone, and It was obtained using possible by-product through the treatment waste water. For the three reactors with the same volume ; Blank reactor, Disturbance plate reactor, Packed-bed reactor ; the results were as follows : For the blank reactor COD removal efficiency in the pH = 4 (HRT : 6hr) was 28.5%, COD removal efficiency in the pH = 7 (HRT : 6hr) was 28.6%, and COD removal efficiency in the pH = 10 (HRT : 6hr) was 27.8%. For the disturbance plate reactor COD removal efficiency in the pH = 4 (HRT : 6Min.) was 86.5%, COD removal efficiency in the pH =7 (HRT : 6Min.) was 84.4%, and COD removal efficiency in the pH = 10 (HRT : 60Min.) was 86.8%. For the packed-bed reactor COD removal efficiency in the pH = 4 (HRT : 40Min.) was 76.0%, COD removal efficiency in the pH = 7 (HRT : 40Min.) was 81.3%, and COD removal efficiency in the pH = 10 (HRT : 40Min.) was 84.6%. After O3 treatment using possible by-product(Na2SO4) was 150g/ℓ.

• Ecology and Resilient Infrastructure
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• v.5 no.3
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• pp.145-155
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• 2018

In a monsoonal climate, the soil seed bank can play an important role in plant regeneration after the severe annual floods that disturb above-ground vegetation within the riparian zone. To investigate the relationship between the soil seed bank and vegetation, we measured the species composition of the soil seed bank and the extant above-ground vegetation in six major plant communities (Artemisia selengensis, Miscanthus sacchariflorus, Persicaria nodosa, Phalaris arundinacea, Phragmites japonica, and Rorippa palustris) in the Cheongmicheon Stream, Korea. A total of 21 species germinated from the floodplain soil seed banks. The most diverse seed bank (21 species) was found in the A. selengensis community, wheres the lowest number of species was found in the R. palustris community (2 species). Most soil seed banks were composed of annuals (90%), exceptions being Rumex crispus and Artemisia princeps, which are perennial ruderals. The similarity of species composition between the soil seed bank and above-ground vegetation was low with Sorensen's similarity indices averaging 29% (range 12 - 42%). Crucially, existing dominant perennials of the extant vegetation including A. selengensis, M. sacchariflorus, P. japonica and P. arundinacea were absent from the soil seed bank. In conclusion, the soil seed banks of the floodplains of the Cheongmicheon Stream were mainly composed of viable seeds of ruderal plants, which could germinate rapidly after severe flood disturbance. The soil seed bank may, therefore, be useful for the restoration of the early succession stages of riparian vegetation after flood disturbances.

• Journal of Ecology and Environment
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• v.29 no.4
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• pp.405-410
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• 2006

Landscape changes for 20 years between 1981 and 2001 in the Wangsuk stream basin located on the central Korea were investigated on the basis of physiognomic vegetation map made from the aerial photograph interpretation and field check. Changes of landscape structure were noticeable in agricultural field and forest landscape elements. Changes in the agricultural fields due to transformation of agricultural pattern into the institutional agriculture dominated landscape change, although urbanization also contributed to such change. The former change due to change of food production structure originated from socio-economic development during this period and the latter to the overpopulation of Seoul. As energy sources for heating and cooking, fertilizer, and fodder for livestock transform from plant materials to fossil fuel, manufactured one, and grain, succession of forest escaped from direct human disturbance dominated change of landscape structure in forested land. Differently from the positive landscape change in the upper area, change in the lower area deteriorated landscape quality by increasing artificial land. It was estimated that such landscape deterioration in the Wangsuk stream basin would influence water quality of the stream. In order to realize sustainable land-use against such environmental degradation, systematic environmental management based on landscape ecological perspective such as "an eco-plan for creating riparian vegetation belt," which is under preparation by Ministry of Environment, was recommended.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.944-951
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• 2011

This paper reports results of a joint experimental and numerical investigation of the causes of near-transducer errors due to the combined effect of acoustic and ADCP-induced flow disturbance near the ADCP transducer. The laboratory study focused on an isolated ADCP (deployment without boat). Measurements of the flow disturbance produced by the ADCP in vertical and horizontal planes were obtained acquiring measurements with an Acoustic Doppler Velocimeter (ADV). Concurrent measurements with ADCP and ADV were made to infer additional near-transducer effects in the ADCP measurements. The numerical investigation was designed to extend the inquiry on the near-transducer potential errors when the ADCP is deployed from a boat. Large Eddy Simulation (LES) was conducted to obtain the extent and magnitude of the disturbances induced by the drag acting on a boat-mounted ADCP and by the blockage effect of the instrument and boat. It is found the velocities measured by the ADCP are biased low and differ substantially from the undisturbed channel flow solution within a limited layer beneath the instrument.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.17 no.1
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• pp.147-162
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• 2014

This study aims to provide the biological and geographical materials to identify the changes in population of Family Ardeidae included Egretta alba modesta, Egretta garzetta, Bubulcus ibis, and Nycticorax nycticorax and establish their conservation measurement in terms of the fragmented and deteriorated habitat by human development such as housing and park projects. Wonjucheon Stream was measured the highest species diversity since the survey site was relatively less interfered by the surrounding human beings showing lower disturbance elements. However, the closer the stream comes downstream, the more the artificial disturbance elements generate, confirming that the species better adapted to contamination grow in more density so that the species composition becomes simplified. It implies that feeding place as well as breeding-growing places is also more closely related to the changes in population structure and species composition of Family Ardeidae. The results of Family Ardeidae immigration in Taejang-dong, Wonju, among the other survey sites, revealed that a total of 231 came to the site in 2006; and 210 in 2011, showing more or less reduction in the population. In the mean while, Namyang-dong in Hwaseong City showed the continuous decrease in population number of Family Ardeidae with 135 before development and 60 during development, resulting in the number never growing but continuously narrowing over and over after development. As a result of surveying the number of Family Ardeidae that bred following the findings above, Taejang-dong in Wonju City had 4 species of Family Ardeidae being bred, however, showing the decrease in number of population from 998 in 2006 to 589 in 2011. Namyang-dong in Hwaseong was confirmed to have as many as 352 of the population in 2006 and 230 in 2008; after the deforestation on their habitat, they had not lived in the site any longer, suggesting that the development would significantly affect Family Ardeidae.

• Economic and Environmental Geology
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• v.24 no.3
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• pp.261-276
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• 1991

The main aspect of this study are to clarify igneous activity of igneous rocks, which is a member of various intrusives and volcanics exposed in Naju-Namchang area of southern central zone of Ogcheon Geosynclinal Belt, southern part of Youngdong-Kwangju depression zone of tectonic provinces in Korea. Naju-Namchang area are subdivided into three rock belts based on occuring of Cretaceous granites. Three rock belts consist of foliated granites, Jurassic granites and Cretaceous granites in central granitic rock belt (C-C), and acidic tuff and lavas in northwest volcanic rock belt(C-NW) and southeast volcanic rock belt(C-SE). Chemical composition of these igneous rocks show mostly similar trend to the Daly's values on Harker diagram and correspond to VAG + Syn-COLG region on Pearce's discrimination diagram. These igneous rocks vary wide range in total REE amount(37.4-221.3ppm) characterized by enriched LREE content and steep negative slope in Eu(-) anomaly. It is concluded each synchronous granites which composed of serveral rock facies is considered to formed by differentiation of co-magma at continental margin, and igneous activity of study area are two more Pre-Cambrian Orogenies, Songrim Disturbance, Daebo Orogeny and Bulkuksa Disturbance.

• Journal of the Korean GEO-environmental Society
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• v.22 no.11
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• pp.23-29
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• 2021

Recently, ground subsidence has been steadily occurring mainly in downtown areas, threatening the safety of citizens. Under the road, various underground facilities such as water supply pipe, sewage pipe, and communication pipe are buried. Due to the aging of these underground facilities and the reckless development of the underground, it is acting as a cause of ground subsidence. Although there is a result of analyzing the risk of ground subsidence according to the deterioration of the existing pipeline, there is no result of analyzing the risk of ground subsidence using the density of pipelines indicating ground disturbance. Therefore, in this study, the density of the underground space was analyzed using the data of six types of representative underground pipelines in Seoul, and a study was conducted on whether there is a correlation with the ground subsidence. As a result, it was found that the density of underground facilities is high in the area where the ground subsidence occurred, indicating that the density of pipelines have an effect on the ground subsidence.

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.375-383
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• 2009

The aims of this study were wintering individuals, usage of foraging sites, potential food availability, daily activity and disturbance factors of White-naped Cranes Grus vipio on the wintering site, Han-river estuary, Goyang and Gimpo city, Korea. We want to provide basic data to conserve the cranes. Maxium population was identified 162 individuals at the middle of February in the river side and mud flat of this study area. Spring migration for breeding was started at the first week of March and finished for two weeks later. White-naped Cranes were used four feeding sites in winter; agricultural area in Hongdopyong, Yihwa-dong, Pyong-dong and Songpo-dong. Expected carrying capacity (ECC) was 334 days (121~909 days). White-naped Cranes departed from roosting site to feeding site at every morning for foraging. If they were disturbed by some factors at feeding sites, they moved to mud flat in the Han river to forage and take a rest. Daily activity was consisted of six category; feeding, alert, locomotion, preening, comfort, social and other behaviors. Feeding was the highest portion among behaviors in the wintering area. Feeding, alert, locomotion and preening in daily activities significantly differed among feeding sites. We watched total 348 times of disturbances in the wintering sites. Artificial disturbances were vehicles, humans, bicycles and motorcycles. Natural disturbances were noises, animals and others. Disturbances in all wintering sites were highest in Yihwa-dong (134 times) and followed by Hongdopyong (109 times), Songpo-dong (64 times) and then Pyong-dong (44 times). And artificial disturbances (228 times) were more than natural disturbances (120 times). Especially, vehicle was one of the most checked factor in the wintering area.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.2
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• pp.99-104
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• 2013

Assessment of noise exposed population is to check the environmental noise level and social influence in order to reduce the risks such as annoyance and disturbance that are generated by environmental noise. Also, this method suggests the preferential noise abatement policy and action plan by accurately finding the area that the noise causes harmful effect to human health. Recently, a noise map, which can predict noise in comprehensive areas, is used for the assessment of noise exposed population, breaking from the methods using existing measures. In particular, countermeasure for the noise can be considered more effectively by using assessment methods of noise exposed population for specific noise levels, areas, and building types which are the main input factors in noise maps. In this study, assessment methods of noise exposed population by using 2 dimensional noise map are compared with those by 3 dimensional noise map.