• Journal of Environmental Policy
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• v.14 no.4
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• pp.45-61
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• 2015

The river environment in Korea has changed significantly after the completion of the Four Major Rivers Project due to the outdated river management methods and thus, it is necessary to modify the current river management process. A typical example of this management is dredging but it is a method that usually results in socio-environmental side effects. Therefore, in order to minimize the socio-environmental impacts of dredging, Korea is currently applying the Environmental Windows, a management practice currently being used in the United States that eliminates the risk of potentially harmful impacts of dredging. The use of statistical methods was suggested to address the issue of data insufficiency and this methodology was applied in the downstream part of the Gangjeong-Goryeong weir located within the Nakdong river basin. The results show that when performing a month of dredging, the optimal period is March whereas the optimal month to start dredging is August in case of an eight-month dredging project. If Korea's flood season is also considered for an eight-month dredging process, then October is the optimal month to start dredging. Non-structural methods such as the Environmental Windows reduce maintenance costs and also bring only short-term side effects to the environment, as opposed to structural methods such as the development of environmentally-friendly dredging machine. Given that few studies have explored this topic in Korea, the findings and suggestions could serve as basic data in studying river dredging in the future.

• Advances in Energy Research
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• v.5 no.2
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• pp.179-205
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• 2017

This research presents an in-depth analysis of location planning of the solar-hydrogen power plants for electricity production in different cities situated in Kerman province of Iran. Ten cities were analyzed in order to select the most suitable location for the construction of a solar-hydrogen power plant utilizing photovoltaic panels. Data envelopment analysis (DEA) methodology was applied to prioritize cities for installing the solar-hydrogen power plant so that one candidate location was selected for each city. Different criteria including population, distance to main road, flood risk, wind speed, sunshine hours, air temperature, humidity, horizontal solar irradiation, dust, and land costare used for the analysis. From the analysis, it is found that among the candidates' cities, the site of Lalezar is ranked as the first priority for the solar-hydrogen system development. A measure of validity is obtained when results of the DEA method are compared with the results of the technique for ordering preference by similarity to ideal solution (TOPSIS). Applying TOPSIS model, it was found that city of Lalezar ranked first, and Rafsanjan gained last priority for installing the solar-hydrogen power plants. Cities of Baft, Sirjan, Kerman, Shahrbabak, Kahnouj, Shahdad, Bam, and Jiroft ranked second to ninth, respectively. The validity of the DEA model is compared with the results of TOPSIS and it is demonstrated that the two methods produced similar results. The solar-hydrogen power plant is considered for installation in the city of Lalezar. It is demonstrated that installation of the proposed solar-hydrogen system in Lalezar can lead to yearly yield of 129 ton-H2 which covers 4.3% of total annual energy demands of the city.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.2
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• pp.31-37
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• 2009

Most damages of civil infrastructures under natural disasters are frequently occurred at surrounding areas of the river or the road. Every year, Recovery for these disaster damages are performed by the government. Recently, the government decide to change current recovery plan system because current recovery plan which doesn't consider future disaster impacts at a site has been proved to be ineffective. Accordingly, new permanency recovery plan system is needed and its corresponding ideas are presented in this research considering more detailed disaster damage classifications and cause assessments. The proposed permanency recovery plan would also provide more systematic and diverse recovery response strategies including both two concepts, for example Preparedness considered by risk assessment and management, and Mitigation investigated by hazard impact analyses.

• Journal of Korea Water Resources Association
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• v.51 no.5
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• pp.417-424
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• 2018

This study analyzed the effect of irrigation reservoirs, antecedent soil moisture conditions (AMC) and Huff time distribution on peak discharge using Monte Carlo simulation. The peak discharge was estimated for four different cases in combination of irrigation reservoir capacity, AMC, and Huff time distribution. Applying 100% reservoir capacity or AMC-III, the peak discharges corresponding return periods of 50~300 years were overestimated by 25~30% compared to those of cases that considered the probability of occurrence for individual condition. Applying the 3rd quantile huff distribution, the peak discharges were overestimated by 5% over the peak discharge that considered the probability of occurrence. The overall results indicated that the effect on the peak flood of Huff distribution was less than AMC and reservoir storage.

• Journal of Wetlands Research
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• v.21 no.4
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• pp.365-373
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• 2019

In this study, we investigated the effect of wave height in coastal areas using discrete wavelet transform in Taehwa river basin in Ulsan. Through the decomposition result of tide data using daubechies level 7 wavelet and Curve Fitting Function, we confirmed that detail components of d₃ and d₄ were semidiurnal and diurnal components and approximation component(a₆) was the long period of lunar fortnight constituent. The decomposed tide data in six level was divided into tide component with periodicity and wave component with non-periodicity using autocorrelation function and fourier transform. Finally, we confirmed that the tide component is consisted 66% and wave component is consisted 34%. So, we quantitatively assessed the effect of wave on coastal areas. The result could be used for coastal flood risk management considering the effect of wave.

• Journal of the Korean Society of Safety
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• v.36 no.2
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• pp.94-100
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• 2021

In general, the industrial complex is a place where factories of various industries are concentrated. It is only as efficient as it is designed. However, the risks vary as there are various industries. These features are also associated with various types of disasters. The dangers of natural disasters such as a typhoon, flood, and earthquake, as well as fire and explosions, are also latent. Many of these risks can make stable production and business activities difficult, resulting in massive direct and indirect damage. In particular, decades after its establishment, the vulnerabilities increase even more as aging and small businesses are considered. In this sense, it is significant to assess the vulnerability of the industrial complex. Thus analysing fire and explosion hazards as stage 1 of the vulnerability evaluation for the major potential disasters for the industrial complex. First, fire vulnerabilities were analyzed quantitatively. It is displayed in blocks for each company. The assessment block status and the fire vulnerability rating status were conducted by applying the five-step criteria. Level A is the highest potential risk step and E is the lowest step. Level A was 11.8% in 20 blocks, level B was 22.5% in 38 blocks, level C was 25.4% in 43 blocks, level D was 26.0% in 44 blocks, and level E was 14.2% in 24 blocks. Levels A and B with high fire vulnerabilities were analyzed at 34.3%. Secondly, the vulnerability for an explosion was quantitatively analyzed. Explosive vulnerabilities were analyzed at 4.7% for level A with 8 blocks, 3.0% for level B with 5, 1.8% for level C with 3, 4.7% for level D with 8, and 85.8% for level E with 145. Levels A and B, which are highly vulnerable to explosions, were 7.7 %. Thirdly, the overall vulnerability can be assessed by adding disaster vulnerabilities to make future assessments. Moreover, it can also assist in efficient safety and disaster management by visually mapping quantified data. This will also be used for the integrated control center of the N-Industrial Complex, which is currently being installed.

• Journal of the Korean Geographical Society
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• v.41 no.1 s.112
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• pp.106-120
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• 2006

Natural or man-made disaster has been expected to be one of the potential themes that can integrate human geography and physical geography. Typhoons like Rusa and Maemi caused great loss to insurance companies as well as public sectors. We have implemented a natural disaster management system for a private insurance company to produce better estimation of hazards from high wind as well as calculate vulnerability of damage. Climatic gauge sites and addresses of contract's objects were geo-coded and the pressure values along all the typhoon tracks were vectorized into line objects. National GIS topog raphic maps with scale of 1: 5,000 were updated into base maps and digital elevation model with 30 meter space and land cover maps were used for reflecting roughness of land to wind velocity. All the data are converted to grid coverage with $1km{\times}1km$. Vulnerability curve of Munich Re was ad opted, and preprocessor and postprocessor of wind velocity model was implemented. Overlapping the location of contracts on the grid value coverage can show the relative risk, with given scenario. The wind velocities calculated by the model were compared with observed value (average $R^2=0.68$). The calibration of wind speed models was done by dropping two climatic gauge data, which enhanced $R^2$ values. The comparison of calculated loss with actual historical loss of the insurance company showed both underestimation and overestimation. This system enables the company to have quantitative data for optimizing the re-insurance ratio, to have a plan to allocate enterprise resources and to upgrade the international creditability of the company. A flood model, storm surge model and flash flood model are being added, at last, combined disaster vulnerability will be calculated for a total disaster management system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.17-25
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• 2017

Owing to recent climate change, the scale of rainfall tends to increase gradually and the risk of flooding has increased. Therefore, the importance of improving the levee management and disaster response is increasing. Levee management in Korea is carried out at the level of damage recovery after the occurrence of damage. Therefore, it is necessary to develop a technology for predicting and managing the levee safety with proactive river management. In this study, a method to estimate the safety against erosion and overflow was suggested. A map of levee safety that can be used as basic data is presented by displaying the levee safety on the map. The levee erosion safety was calculated as the ratio of the internal and external force for each shore type. The levee overflow safety was calculated as the ratio of the maximum conveyance and design flood. The maximum conveyance was a discharge when the level of the river was equal to the level of the levee crown. The levee safety was classified into 5 grades: very safe, safe, normal, dangerous, and very dangerous. As a research area from downstream of Nam River Dam to Nakdong River Junction, the levee safety against erosion and overflow was estimated for all levees and all cross-sections of the river. The levee safety was displayed on a map using GIS. Through the levee safety map as a result of this study, the levee safety can be observed intuitively. Using the levee safety map, a maintenance plan for a river can be easy to build. This levee safety map can be used to help determine the priority of investment for efficient budget used.

• Journal of Korea Water Resources Association
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• v.52 no.9
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• pp.647-655
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• 2019

Although problems such as river management and flood control have occurred continuously in the Imjin and Bukhan river basin, which are shared by South and North Korea, efforts to manage the basin have not been carried out consistently due to limited cooperation. As the magnitude and frequency of hydrologic phenomena are changing due to global climate change, it is necessary to prepare countermeasures for the rainfall variation in the shared river basin area. Therefore, this study was aimed to project future changes in extreme precipitation in South-North Korea shared river basin by applying 13 Global Climate Models (GCM). Results showed that the probability rainfall compared to the reference period (1981-2005) of the shared river basin increased in the future periods of 2011-2040, 2041-2070 and 2071-2100 under the Representative Concentration Pathways (RCP)4.5 and RCP8.5 scenarios. In addition, the rainfall frequency over the 20-year return period was increased in all periods except for the future periods of 2041-2070 and 2071-2100 under the RCP4.5 scenario. The extreme precipitation in the shared river basin has increased both in magnitude and frequency, and it is expected that the region will have a significant impact from climate change.

• Journal of Wetlands Research
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• v.21 no.spc
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• pp.149-156
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• 2019

Assessing the hydrological safety of existing dams against climate change and providing appropriate adaptation measures are important in terms of sustainable water supply and management. Korean major dams ensure their safety through periodic inspections and maintenance according to 'Special Act on the safety control and maintenance of establishments'. Especially when performing a full safety examination, principal engineer must assess the hydrological safety and prepare for potential risks. This study employed future probable maximum precipitation (PMP) estimated using outputs of regional climate models based on RCP4.5 and RCP8.5 greenhouse-gas emission scenarios to assess climate change impact on existing dam's future hydrological safety. The analysis period was selected from 2011 to 2040, from 2041 to 2070, and from 2071 to 2100. Evaluating the potential risk based on the future probable maximum flood (PMF) for four major dams (A, B, C, I) showed that climate change could induce increasing the overflow risk on three dams (A, B, I), although there are small differences depending on the RCP scenarios and the analysis periods. Our results suggested that dam managers should consider both non-structural measures and structural measures to adapt to the expected climate change.