• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.439-449
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• 2018

Many potential sources of bias are used in several steps of the radar-rainfall estimation process because the hydrological and meteorological radars measure the rainfall amount indirectly. Previous studies on radar-rainfall uncertainties were performed to reduce the uncertainty of each step by using bias correction methods in the quantitative radar-rainfall estimation process. However, these studies do not provide comprehensive uncertainty for the entire process and the relative ratios of uncertainty between each step. Consequently, in this study, a suitable approach is proposed that can quantify the uncertainties at each step of the quantitative radar-rainfall estimation process and show the uncertainty propagation through the entire process. First, it is proposed that, in the suitable approach, the new concept can present the initial and final uncertainties, variation of the uncertainty as well as the relative ratio of uncertainty at each step. Second, the Maximum Entropy Method (MEM) and Uncertainty Delta Method (UDM) were applied to quantify the uncertainty and analyze the uncertainty propagation for the entire process. Third, for the uncertainty quantification of radar-rainfall estimation at each step, two quality control algorithms, two radar-rainfall estimation relations, and two bias correction methods as post-processing through the radar-rainfall estimation process in 18 rainfall cases in 2012. For the proposed approach, in the MEM results, the final uncertainty (from post-processing bias correction method step: ME = 3.81) was smaller than the initial uncertainty (from quality control step: ME = 4.28) and, in the UDM results, the initial uncertainty (UDM = 5.33) was greater than the final uncertainty (UDM = 4.75). However uncertainty of the radar-rainfall estimation step was greater because of the use of an unsuitable relation. Furthermore, it was also determined in this study that selecting the appropriate method for each stage would gradually reduce the uncertainty at each step. Therefore, the results indicate that this new approach can significantly quantify uncertainty in the radar-rainfall estimation process and contribute to more accurate estimates of radar rainfall.

• Journal of Environmental Impact Assessment
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• v.30 no.2
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• pp.117-131
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• 2021

Urban development is continuously being carried out to stabilize housing supply. The importance of ecosystem services assessments considering the various urban spatial structures is emerging as land use change in the wake of urban development has impact on the provision of ecosystem services. However, few studies are available as to the effects of land use transition in agricultural land due to urban development on ecosystem services. The purpose of this study is to examine the applicability of decision-making in the urban planning process by analyzing the impact of land use change on ecosystem services due to urban development. Therefore, the scenario was set on before and after the city development, targeting Namyangju Wangsuk Zone 1 and InVEST model was used to compare and analyze changes in value of ecosystem services. Analysis results of ecosystem services before the urban development, it turned out that habitat quality and water yield increased overtime but carbon storage and crop production decreased. Analysis results of ecosystem services after the urban development indicated that all items in ecosystem services by scenario decreased more than in 2018. Among the scenarios of urban development, compact city had the lowest value of water resource supply but had the highest value in terms of habitat quality, carbon storage amount, and crop production. The study results demonstrate that the compact city has positive effects on ecosystem services and is expected to be used as the basic data for supporting policy decision-making in the establishment of future urban development and management plans.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.145-158
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• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Korean Journal of Environmental Agriculture
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• v.24 no.1
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• pp.34-39
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• 2005

To investigate the germanium content in paddy soil in Gyeongnam province, 310 paddy soil samples were collected at 19 areas in Gyeongnam, Ulsan and Busan. Contents of germanium in paddy soils were analyzed in different topographies, soil types and soil textures. Average content of germanium in Gyeongnam was 0.24 mr/kg, those of Masan, Jinju and Hadong were above 0.30 mg/kg. Germanium content with different topographies were no difference. Germanium contents in different soil types were 0.27 mg/kg in well adapted soil and 0.23 mg/kg in poorly drained soil. Germanium contents in different soil textures were 0.27 mg/kg in silt loam and 0.23 mg/kg in sandy loam. To determine germanium content on agricultural product in the field, content of germanium in cereals, vegetables and fruits were analyzed. Germanium content of agricultural product was high in the order of cereals>vegetables>fruits. In case of vegetables, germanium contents were high in the order of leaf vegetables>root vegetables>fruit vegetables. Germanium contents were high with 62 and $65{\mu}g/kg$ in lettuce and young radish, respectively. To analyze the germanium content in medicinal plant, samples were collected from 19 medicinal plants at Hamyang areas. Germanium contents in Angelica keiskei, Ligusticum chuanxiong, Panax ginseng and Atractylodes macrocephala were relatively high with $100{\mu}g/kg$ above.

• Korean Journal of Environmental Biology
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• v.24 no.3
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• pp.221-229
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• 2006

The effects of ultrasonication on phytoplankton were investigated in two ponds in which physicochemical and biological water quality was similar, one as a treatment and the other as a control. The samples were collected from August 18 to September 30 in 2003. Traditional morphological analysis showed that Bacillariophyceae dominated phytoplankton community in both ponds. The abundance of Cyanophyceae was lower in the phytoplankton community of the sonicated pond than that of control pond. We used DGGE (denaturing gradient gel electrophoresis) to analyze the diversity and change of phytoplankton community in two ponds. The DGGE banding patterns of 16S rRNA gene and sequence analysis demonstrated that Oscillatoria acuminata and CFB (Cytophaga-Flavobacterium-Bacteroides) group bacterium appeared in the treated pond, and the control pond was dominated by Synechococcus sp. and Aphanizomenon flos-aquae. Especially, Pseudanabaena sp. dominated during the ultrasonic cessation in the treated pond. The DGGE profiles of 18S rRNA gene and sequence analysis showed that the treated pond was dominated by Chlamydomonas reinhardtii and the control pond by C. reinhardtii and Pteromonas protracta. In conclusion, the ultrasonication affected the reduced growth of cyanobacteria, particularly Pseudanabaena.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.158-166
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• 2018

Contrary to urban development, urban regeneration is a process of land development through conservation, restoration, and management. In particular, ecologically based urban regeneration is an attempt to improve the quality of life in an area, establish a stable settlement space, and revitalize the local economy by considering the ecological environment. In this regard, the objectives of this study were to establish theoretical concepts and analyze the successful foreign cases of ecologically based urban regeneration, and propose a direction of socio-economic regeneration along with the physical-environmental regeneration of urban areas in Korea. The study results suggest the following. First, strategies must be developed to coordinate public transportation, such as buses and subways, by considering the importance of bicycle riders, along with the sustainable-commuting system. Second, both the importance of planning parks and trails around water systems in various scales while maintaining the existing natural environment as well as using natural elements, such as electric vehicles and wind-power generation systems, were emphasized. Third, urban regeneration for increased energy efficiency requires specific architectural planning and facilities. Fourth, education and research for easy access by the public, as well as public-private partnership, will be needed in the regeneration process.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.218-224
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• 2010

The purpose of this case study is to analyze the environmental and sociological impacts on a golf course construction at the damaged area of a previous limestone mine. Due to a long term of the open-pit mining, that site had been abandoned with geographical and ecological destruction before it was renovated to Ostar Danyang public golf course. This study is focused on the review of restoring the ecosystem through golf course construction procedures. Literature surveys of restoration through golf course construction in Japan and Canada were analyzed the procedure of utilization of previously existed lime mine. The sociological and environmental changes before and after construction were compared and analyzed. Environmental impacts on geographical, animal and plant ecology, and water quality were not affected or significantly improved after golf course construction from the mining site existed before. The local economy was also improved by increasing employment of resident and tax payment to local government. The construction of golf course could be one of the typical alternatives of ecological restoration of abandoned lime mine. Moreover in this project, minimizing the environmental impacts on surrounding ecosystem was emphasized by a larger size of developing construction. The harmonious lay-out on nature and artificial landscape were also considered a very first stage of construction procedure.

• Journal of the Korean Regional Science Association
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• v.31 no.4
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• pp.25-45
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• 2015

The government has implemented the projects of restoring the ecological integrity of streams to improve its water quality and provide resting places with local residents. Because the projects require huge public investments, their economic feasibility should be investigated through ex-post examination of their benefits. This study attempts to analyze the economic feasibility of restoring the ecological integrity using specific cases of Namyang stream in Hwaseong, Gyeonggi and Yugu stream in Gongju, Chungnam. The contingent valuation (CV) method is employed to measure the benefits. To this end, a professional polling firm conducted two CV surveys of 210 and 209 households for Hwaseong and Gongju, respectively. The willingness to pay (WTP) model used in the study is based on utility difference approach and the single-bounded dichotomous choice spike model. The results reveal that the WTP for restoring ecological integrity of the Namyang and Yugu streams are estimated to be 3,140 and 10,121 won per household per year. Interestingly, the latter is about three times greater than the former. The quantitative information can be used in economic feasibility analysis of the projects of restoring the ecological integrity of the Namyang and Yugu streams.

• Journal of Wetlands Research
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• v.7 no.1
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• pp.119-128
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• 2005

Sediment yield and sediment transport in a basin bring about decrease of conveyance by the change of bed section, and have an influence on an aggravation of water quality and freshwater ecosystem. This study is to analyze the characteristics of outflow sediment according to land-use in Mushim-cheon flowing through forest area, farmland area and urban area. The upper stream of Mushim-cheon consists of forest area and farmland area. The suspended sediment is observed through 10 rainfall events in 5 sites. As a result of analyzing characteristics of landuse, the site of Bangse-gyo takes up 69% of Mushim-cheon, and farmland area(27.1%) and forest area(63.7%) take up 90.8% in Bangse-gyo. Accordingly, these two areas have the high possibility to occur sediment. The suspended sediment of this site shows the highest concentration. Transferring to the downstream and the urban, the concentration of suspended sediment gets decreased. The suspended sediment occurred in the upper stream of Mushim-cheon prior to Bangse-gyo has an influence on the downstream, and has a slight influence on the urban area. Also relational formula about suspended sediemtn and discharge is leaded. As a result of this formula, $R^{2}$ is 0.506 in the upper stream and is 0.656 in the downstream.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.1
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• pp.10-21
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• 2007

The Doam-dam watershed, located at Kangwon Province, Korea, has been experiencing significant changes in land uses, conversion from forest to agricultural/urban areas, with human involvements. However, no thorough investigation of the landscape impacts of land use changes was performed at this watershed using the scientific analytical tool. Thus, the FRAGSTATS model was utilized to quantitatively analyze the landscape impacts of forest fragmentation in this study. To provide the detailed explanations for 11 landscape indices considered in this study, two artificial and simplified landscapes, before and after fragmentations, were constructed. Using these 11 indices, the landscape impacts of forest fragmentation in 19 subwatersheds of the Doam-dam watershed were analyzed. The S1 subwatershed, one of 19 subwatersheds of the Doam-dam watershed, was found to have experienced the significant forest fragmentation from 1985 to 2000 based on landscape analysis using the FRAGSTATS model. The results obtained in this study can be used to evaluate the water quality impacts of forest fragmentations/land use changes at watershed scale level, and establish environment-friendly land use planning based on the results obtained using landscape analytical tool, FRAGSTATS.