• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.2
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• pp.103-112
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• 2011

The purpose of this study is to specify the prior eco-preserve zone by establishing the eco-landscape unit on the stream corridor and evaluating the stream ecosystem in the dam basin. The fundamental ecological data was surveyed and collected through "the ecosystem project on Yongdam multipurpose dam watershed" from 2008 to 2009. The Yongdam Dam Watershed has several streams, Jujacheon, Jeongjacheon and Guryangcheon, of which the area is $930km^2$, stretching to Jinangun, Jangsugun and Mujugun Jellabukdo. In spite of being used for drinking purpose, the dam water quality and ecosystem is threatened by in-watershed pollution produced by development, golf course grounds and sports complex, etc. The landscape unit of stream corridor was zoned across by 250m, 500m, and 750m from the vicinity line of stream, which was decided to the accuracy of mapping and surveying. Types of evaluation are the Stream Corridor Evaluation(SCE) and the Vegetated Area Evaluation(VAE). In the process of SCE, several indices were analysed, fish species diversity, species peculiarity, and stream naturality. Indices for VAE were forest stand map, vegetation protection grade, species diversity and peculiarity for wild bird and mammal life. The importance of the ecological items is categorized into three levels and overlapped for specifying the prior preserve zone. The area at which legally protecting species appeared is categorized as absolute preserve area. This study might be meaningful for proposing the evaluation process of a stream corridor ecosystem, which can synthesize a lot of individual ecological surveys. We hope further research will be actively performed about the ecotope mapping which is based on a individual wildlife territory and habitats and also their relationships.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.208-214
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• 2010

This study aimed at the introduction of desktop method for assessment of environmental flows developed by International Water Management Institute (IWMI) recently and its application to Geum river basin. This scheme simulated the influence on aquatic ecosystem caused by watershed development and in turn the decrease of water quantity keeping the river's own flow regime. It was found to be as very effective method although it had simple structure. Flow duration curves for different environmental classes at Sutong and Gongjoo sites were estimated according to the natural conditional scenario of Geum river basin and the results were relatively compared well with the previous studies. The behaviors of monthly average runoff time series of both sites showed the level of A class. The results of this study would provide the fundamental data to establish the future plans of monitoring or management for aquatic ecosystem of Geum river basin.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.933-937
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• 2010

This study aimed at the introduction of desktop method for assessment of environmental flows developed by IWMI(International Water Management Institute) recently and its application to Geum river basin. This scheme simulated the influence on aquatic ecosystem caused by watershed development and in turn the decrease of water quantity keeping the river's own flow regime. It was found to be as very effective method although it had simple structure. Flow duration curves for different environmental classes at Sutong and Gongjoo sites were estimated according to the natural conditional scenario of Geum river basin and the results were relatively compared well with the previous studies. The behaviors of monthly average runoff time series of both sites showed the level of A class. The results of this study would provide the fundamental data to establish the future plans of monitoring or management for aquatic ecosystem of Geum river basin.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.7 no.1
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• pp.10-18
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• 2004

The urban ecosystem, unlike the natural ecosystem, has been affected by the urban environment, so the existences of normal creatures have been threatened and eventually the stability has declined to consist of those that have adapted to such. Therefore, by creating a list of such organisms, their number of variety can be found out and their ecological distinction can be understood. Because flora is known to be an ecological index reflecting region's effects of human and societal environments, weather, and climates, it is a useful method of finding out the ecological position and distinctiveness of that region. The study site is part of watershed at Yangjae Stream, Kahngnam-ku, Seoul. In this study, the difference of flora in each land use type are investigated by plant identification. The purpose of this study is to evaluate the city's plant surviving environment, and eventually to contribute to the restoration of urban green spaces by finding out the plants which are appropriate for the corresponding environment. After doing the study, it was found that the urban forest is the most stable urban ecosystem while the urban park is seriously disturbed, and ecologically unstable. The urban stream is also disturbed continuously.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.19 no.1
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• pp.171-184
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• 2016

Suncheonman-Bay and its surrounding areas play important roles as habitats for migratory birds. However, sustainable management of these areas is difficult because of the development pressure of private lands. Therefore, the areas surrounding Suncheonman-Bay must be classified as additional protected areas; for this, it is necessary to gather concrete and objective evidence and ensure protected area management. Further, compensation measures must be considered when acquiring a private property as an additional protected area. In this study, we distinguish protected areas, such as core, buffer, and transition areas, within a private area by using data from the Winter Waterbird Census of Korea and MARXAN software, a spatial conservation prioritization tool. We applied ecosystem services to apply Payment for Ecosystem services (PES) as compensation measures. Watershed conservation (supply), climate control (regulation), supporting habitats (support), and recreation (culture) etc. were evaluated by calculating the economic value of these ecosystem services. Eastern, western, and northern forests and rice fields of Suncheonman-Bay were shown to have a number of core areas for the preservation of endangered species. The ecosystem service value of the additional protected areas was estimated at 17.5 million KRW/ha/year. We believe that our study result could be used to establish protected areas to preserve major habitats, as well as include areas adjacent to such major habitats that play a vital role in endangered species conservation. In addition, through this study, we highlight the need for an objective basis to establish protected areas.

• Korean Journal of Ecology and Environment
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• v.40 no.4
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• pp.527-536
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• 2007

In this study, we applied 10-metric health assessment model, based on the Index of Biological Integrity (IBI) during 2006 in the Changwon Stream, which is located in the Changwon city, Gyeongnam province, S. Korea, and then compared with water quality data. The Index of Biological Integrity (IBI) in the Changwon Stream varied from 18 to 38 in the watershed depending on the sampling location and averaged 30.3 (n=6) during the study. Analysis of tolerance guilds showed that the proportion of sensitive species was 13%, but tolerant and intermediate species were 34% and 53%, respectively. Qualitative Habitat Evaluation Index (QHEI) averaged 43.3 (range: 65-104, n=6) indicating non-supporting condition, based on the criteria of U.S. EPA (1993). Values of QHEI showed a typical longitudinal decreases from the headwater reach to the downstream location, except for Site 1 with a low QHEI value by artificial habitat by concrete construction. Minimum QHEI was found in Site 4 where fish diversity was minimal. Conductivity increased continuously along the gradients and especially showed abrupt increases in the downstream sites along with turbidity. Stream ecosystem health of IBI matched to the values of QHEI except for S6. Low IBI values in the sites 4 and 5 was considered to be a result of combined effects of chemical pollutions and habitat degradations. Our results support the hypotheses of Plafkin et ai. (1989) that physical habitat quality directly influences the trophic structure and species richness, and is closely associated with IBI values.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.27-27
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• 2003

Lake Texoma is located on the border of southern Oklahoma and northern Texas. It has 93,000 surface acres, and is a focus of the recreation, and farming industries in the region. There are potential stressors around the Lake Texoma watershed that may cause adverse ecological effects in the lake. System assimilative capacity (SAC) is the ability of abiotic and biotic processes to atteuniate the stressors. SAC Exceeded indicates potential of occuring adverse eco-effects. A number of representative chemical release sites and stressor sources in the surrounding watershed were characterized, and several impact sites having stressors sources, such as being near agriculture, landfills, housing areas, oil production fields and heavy use recreational activity, were selected for surface water, sediment, and groundwater monitoring. A paired reference site, having similar physical characteristics as its impact site, was also chosen based on its proximity to the impact site. Lake water samples were collected at locations identified as marina entrance, gasoline filling station, and boat dock at five marinas selected on Lake Texoma from September 1999 to December 2001. Paired water and sediment samples were also collected. Groundwater samples were collected at about 70 producing monitoring wells. Water quality parameters measured were inorganics (nitrate, nitrite, orthophosphate, ammonia, sulfate, and chloride), dissolved methane, total organic carbon (TOC) (or DOC), volatile organic compounds (VOCs) such as methyl tert-butyl ether (MTBE) and BTEX, and a suite of metals. Biotic communities were evaluated at impact and reference sites. Five basic components were measured; two terrestirial components (plants and bird comminitires) and three aquatic components (benthic inverbrates, litteral-zone fishes, ecosystem attribures). Potential impacts to these comminites were evaluated.

• Journal of Korean Society on Water Environment
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• v.31 no.3
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• pp.319-327
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• 2015

The present study was carried out to develop biological criteria for aquatic ecosystem health assessment using composition and diversity of collected species. The sampling sites were a total of 67 sites in the Han River (29 sites) and the Nakdong River (38 sites), May and September 2012. During the survey period fish were collected totally 93 species. In each water system, 73 and 61 species were collected in the Han River and the Nakdong River respectively. The current composition of fish species between the Han River and Nakdong River showed similar pattern. The dominant species was Zacco platypus of the Han River, and the Nakdong River was Opsariichthys uncirostris. In particular, ecological characteristics of O. uncirostris frequently appeared in general polluted waters. In conclusion, in the Nakdong River, average value of FAI (Fish Assessment Index) was averaged 41.3, indicating a "poor condition", and the Han River was 53.1, indicating a "poor condition". The aquatic health of the Nakdong River assessed based on FAI was considered to be worse than that of the Han River.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.1-10
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• 2012

Throughout much of the world, many ecological problems have arisen in watersheds where a significant portion of stream flows are diverted to support agriculture production. Within endorheic watersheds (watersheds whose terminus is a terminal lake) these problems are magnified due to the cumulative effect that reduced stream flows have on the condition of the lake at the stream's terminus. Within an endorheic watershed, any diversion of stream flows will cause an imbalance in the terminal lake's water balance, causing the lake to transition to a new equilibrium level that has a smaller volume and surface area. However, the total mass of Total Dissolved Solids within the lake will continue to grow; resulting in a significant increase in the lake's TDS concentration over time. The ecological consequences of increased TDS concentrations can be as limited as the intermittent disruption of productive fisheries, or as drastic as a complete collapse of a lake's ecosystem. A watershed where increasing TDS concentrations have reached critical levels is the Walker Lake watershed, located on the eastern slope of the central Sierra Nevada range in Nevada, USA. The watershed has an area of 10,400 sq. km, with average annual headwater flows and stream flow diversions of 376 million $m^3/yr$ and 370 million $m^3/yr$, respectively. These diversions have resulted in the volume of Walker Lake decreasing from 11.1 billion m3 in 1882 to less than 2.0 billion $m^3$ at the present time. The resulting rise in TDS concentration has been from 2,560 mg/l in 1882 to nearly 15,000 mg/l at the current time. Changes in water management practices over the last century, as well as climate change, have contributed to this problem in varying degrees. These changes include the construction of reservoirs in the 1920s, the pumpage of shallow groundwater for irrigation in the 1960s and the implementation of high efficiency agricultural practices in the 1980s. This paper will examine the impacts that each of these actions, along with changes in the region's climate, has had on stream flow in the Walker River, and ultimately the TDS concentration in Walker Lake.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.22-34
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• 2004

An artificial disturbance like fragmentation in watershed forest has impacted a sustainability of watershed ecosystem, therefore this research quantified the landscape structure in the Geumho river watershed using landscape indices and GIS. Landscape indices were calculated from the forest distributed maps for 24 subwatersheds. Three common factors, which explained about 85% of the variation in the original data, were extracted by a factor analysis. The fragmentation gradient in forest landscape, which was calculated from the factor scores, was correlated with proportion of urban land (r=0.827, p<0.01, $R^2$=0.685), elevation (r=-0.637, p<0.01) and slope gradient (r=-0.593, p<0.01). The result of the study presented that the methodology and the values of landscape indices to assess the structural patterns of forest landscape for the Geumho river watershed management. Future research will be directed towards the detection of impacts of landscape patterns and their changes on the integrity of watershed environments.