• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.204-204
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• 2016

Thailand had set the National Water Management Strategy which covered main six areas in the next 12 years, i.e., by priority: (1) water for household, (2) water for agricultural and industrial production, (3) water for flood and drought management, (4) water for quality issue, (5) water from forest conservation and soil erosion protection, (6) water resources management. However due to the climate change impact, there is a question for all strategies is whether to complete this mission under future climate change. If the impact affects our target, we have to clarify how to mitigate or to adapt with it. Vulnerability assessment was conducted under the framework of ADB's (with the parameters of exposure, sensitivity and adaptive capacity) and the assessments were classified into groups due to their different characteristic and the framework of the National Water Management Strategy, i.e., water supply (rural and urban), water for development (agriculture and others), water disasters (floods (flash, overflow), drought, water quality). The assessments identified the parameters concerned and weight factors used for each groups via expert group discussions and by using GIS mapping technology, the vulnerability maps were produced. The maps were verified with present water situation data (floods, drought, water quality). From the analysis result of this water resources management strategy, we found that 30% of all projects face the big impacts, 40% with low impact, and 30% for no impact. It is clear that water-related agencies have to carefully take care approximately 70% of future projects to meet water resources management strategy. It is recommended that additional issues should be addressed to mitigate the impact from climate risk on water resource management of the country, i.e., water resources management under new risk based on development scenarios, relationship with area-based problems, priority definition by viewpoints of risk, vulnerability (impact and occurrence probability in past and future), water management system in emergency case and water reserve system, use of information, knowledge and technology in management, network cooperation and exchange of experiences, knowledge, technique for sustainable development with mitigation and adaptation, education and communication systems in risk, new impact, and emergency-reserve system. These issues will be described and discussed.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.152-152
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• 2021

The importance of groundwater has long been recognized, but the ground water potential to become contaminated as a result of human activities has only been recognized in recently. Before 1980 it was thought that soils served as filters, preventing harmful substances deposited at the surface from migrating into groundwater. Today it is known that soils have a finite capacity to protect groundwater. It can be contaminated from divers sources. Therefore, Assessment of aquifer vulnerability to pollution is essential for the protection and management of groundwater and land use planning. In this study, we used DRASTIC and AVI for groundwater vulnerability to contamination assessment. the different methods were applied to the southern coastal sedimentary basin of Benin and DRASTIC method was modified in two different steps. First, we modified DRASTIC by adding land use parameter to include the actual pollution sources (DRASTIC_LcLu) and second, classic DRASTIC weights was modified using Shannon's entropy (Entropy weight DRASTIC). The reliability of the applied approaches was verified using nitrate (NO3^-) concentration and by comparing the overall vulnerability maps to the previous researches in the study area and in the world. The results from validation showed that the addition of landcover/land use parameter to the classic DRASTIC helps to improve the method for better definition of the vulnerable areas in the basin and also, the weight modification using entropy improved better the method because Entropy weight DRASTIC_LcLu showed the highest correlation with nitrate concentration in the study basin. In summary the weight modification using entropy approach reduced the uncertainty of the human subjectivity in assigning weights and ratings in the standard DRASTIC.

• Journal of Korea Water Resources Association
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• v.52 no.10
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• pp.729-742
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• 2019

Natural disasters such as floods has been increased in many parts of the world, also Korea is no exception. The biggest part of natural damage in South Korea was caused by the flooding during the rainy season in every summer. The existing flood vulnerability analysis cannot explain the reality because of the repeated changes in topography. Therefore, it is necessary to calculate a new flood vulnerability index in accordance with the changed terrain and socio-economic environment. The priority of the investment for the flood prevention and mitigation has to be determined using the new flood vulnerability index. Total 25 urban districts in Seoul were selected as the study area. Flood vulnerability factors were developed using Pressure-State-Response (PSR) structures. The Pressure Index (PI) includes nine factors such as population density and number of vehicles, and so on. Four factors such as damage of public facilities, etc. for the Status Index (SI) were selected. Finally, seven factors for Response Index (RI) were selected such as the number of evacuation facilities and financial independence, etc. The weights of factors were calculated using AHP method and Fuzzy AHP to implement the uncertainties in the decision making process. As a result, PI and RI were changed, but the ranks in PI and RI were not be changed significantly. However, SI were changed significanlty in terms of the weight method. Flood vulnerability index using Fuzzy AHP shows less vulnerability index in Southern part of Han river. This would be the reason that cost of flood mitigation, number of government workers and Financial self-reliance are high.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.85-97
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• 2022

In this study, a method for an integrated flood risk mapping was proposed that simultaneously considers the flood inundation map indicating the degree of risk and the disaster vulnerability index. This method creates a new disaster map that can be used in actual situations by providing various and specific information on a single map. In order to consider the human, social and economic factors in the disaster map, the study area was divided into exposure, vulnerability, responsiveness, and recovery factors. Then, 7 indicators for each factor were extracted using the GIS tool. The data extracted by each indicator was classified into grades 1 to 5, and the data was selected as a disaster vulnerability index and used for integrated risk mapping by factor. The risk map for each factor, which overlaps the flood inundatoin map and the disaster vulnerability index factor, was used to establish an evacuation plan by considering regional conditions including population, assets, and buildings. In addition, an integrated risk analysis method that considers risks while converting to a single vulnerability through standardization of the disaster vulnerability index was proposed. This is expected to contribute to the establishment of preparedness, response and recovery plans for providing detailed and diverse information that simultaneously considers the flood risk including social, humanistic, and economic factors.

• Journal of Environmental Policy
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• v.5 no.4
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• pp.1-18
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• 2006

Recently, the damage by fresh flood increases in Gangwon-do and Gyeongsangbuk-do of the north-eastern area of Korea. Even though the recent pattern of rain fall keeps changing, there is no strategy to mitigate damage by disaster. For the appropriate measure and policy for decreasing damage, an index for vulnerability is necessary to provide evidence of local climate change. The present work analyzes the flooding damage cost during the past 20 years. During 80's, the southern area of Korea was seriously damaged by over-floods on the agricultural ground. After that time, the loss and damage has decreased in the southern area but the middle part has shown slight but distinct increases of damage. The absolute coast of damage in the northern part has kept constant. However, the relative regional damage to the total country damage has kept increasing over 20 years in the same area. The surface area of floods is strongly correlated with the regional damage cost in the southern part but the north-eastern part has weak correlation between flooded area and cost. It implies that the recent damage in the north-eastern mountain area was not caused by flood itself but the other factors such as avalanches. The present work expects that the damage cost can be a good proxy value for index for climate change impact assessment.

• Journal of Climate Change Research
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• v.2 no.1
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• pp.43-54
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• 2011

Recently, due to severe rainfall by the global climate change, natural disasters such as landslide had also been increased rapidly all over the world. Therefore, it has been very necessary to assess vulnerability of landslide and prepare adaptation measures to future climate change. In this study, we employed sensitivity, exposure and adaptative capacity as criteria for assessing the vulnerability of landslide due to climate change. Spatial database for the criteria was constructed using GIS technology. And vulnerability maps on the entire Korea of past and future were made based on the database. As a result, highly vulnerable area for landslide was detected in most area of Gangwon-do, the east of Gyeonggi-do, and southeast of Jeollanam-do, and the southwest of Gyeongsangnam-do. The result of landslide vulnerability depends on time shows that degree of very low class and low class were decreased and degree of moderate, high, and very high were increase from past to the future. Especially, these three classes above low class were significantly increased in the result of far future.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.105-117
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• 2010

The topographical depressions in urban areas, the lack in drainage capability, sewage backward flow, road drainage, etc. cause internal inundation, and the increase in rainfall resulting from recent climate change, the rapid urbanization accompanied by economic development and population growth, and the increase in an impervious area in urban areas deteriorate the risk of internal inundation in the urban areas. In this study, the vulnerability of internal inundation in urban areas is analyzed and SWMM model is applied into Oncheoncheon watershed, which represents urban river of Busan, as a target basin. Based on the results, the representative storm sewers in individual sub-catchments is selected and the risk of vulnerability to internal inundation due to rainfall in urban streams is analyzed. In order to analyze the risk and vulnerability of internal inundation, capacity is applied as an index indicating the volume of a storm sewer in the SWMM model, and the risk of internal inundation is into 4 steps. For the analysis on the risk of internal inundation, simulation results by using a SMMM model are compared with the actual inundation areas resulting from localized heavy rain on July 7, 2009 at Busan and comparison results are analyzed to prove the validity of the designed model. Accordingly, probabilistic rainfall at Busan was input to the model for each frequency (10, 20, 50, 100 years) and duration (6, 12, 18, 24hr) at Busan. In this study, it suggests that the findings can be used to preliminarily alarm the possibility of internal inundation and selecting the vulnerable zones in urban areas.

• Land and Housing Review
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• v.15 no.2
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• pp.57-71
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• 2024

This study aims to develop an evaluation method for solar power facilities considering disaster impacts and to analyse the vulnerabilities of existing facilities. Haenam-gun in Jeollanam-do, where the reassessment of existing facilities is urgent, was selected as the study area. To evaluate the vulnerability from a more objective perspective, principal component analysis and entropy methods were utilised. Seven vulnerability assessment indicators were selected: maximum hourly rainfall, maximum wind speed, number of typhoon occurrence days, number of rainfall days lasting more than five days, maximum daily rainfall, impermeable area ratio, and population density. Among these, maximum hourly rainfall, maximum wind speed, maximum daily rainfall, and number of rainfall days lasting more than five days were found to have the highest weights. The overlay of the derived weights showed that the southeastern regions of Haenam-eup and Bukil-myeon were classified as Grade 1 and 2, whereas the northern regions of Hwawon-myeon, Sani-myeon, and Munnae-myeon were classified as Grade 4 and 5, indicating differences in vulnerability. Of the 2,133 facilities evaluated, 91.1% were classified as Grade 3 or higher, indicating a generally favourable condition. However, there were more Grade 1 facilities than Grade 2, highlighting the need for countermeasures. This study is significant in that it evaluates solar power facilities considering urban disaster resilience and is expected to be used as a basic resource for the installation of new facilities or the management and operation of existing ones.

• Economic and Environmental Geology
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• v.37 no.6 s.169
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• pp.631-645
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• 2004

This study assesses groundwater vulnerability to contaminants in industrial and residential/commercial areas of the city of Changwon, using DRASTIC technique and groundwater data. The DRASTIC technique was originally applied to situations in which the contamination sources are at the ground surface, and the contaminants flow into the groundwater with infiltration of rainfall. Mostly the industrial area has higher DRASTIC indices than the residential/commercial area. However, a part of the residential/commercial area having much groundwater production and great drawdown is more contaminated in groundwater than other industrial and the residential/commercial areas even if it has lowest DRASTIC indices in the study area. It indicates that groundwater contamination in urban areas can be closely related to excessive pumping resulting in a lowering of the water level. The correlation coefficient between minimum DRASTIC indices and the degree of poor water quality for 10 districts is as low as 0.40. On the other hand, the correlation coefficients between minimum DRASTIC indices and the groundwater discharge rate, and between minimum DRASTIC indices and well distribution density per unit area are 0.70 and 0.87, respectively. Thus, to evaluate the potential of groundwater contamination in urban areas, it is necessary to consider other human-made factors such as groundwater withdrawal rate and well distribution density per unit area as well as the existing seven DRASTIC factors.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.345-352
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• 2023

Recently, the risk of snow disasters has been increasing South Korea. The damages of heavy snow were categorized into direct and indirect. Direct damage is usually the collapse of buildings as houses, greenhouse or barns. Indirect damage is various, for example, traffic congestion, traffic acident, drop damage, and so on. In South Korea, direct damage is severe in rural area, mosty collapse of greenhouse or barns. However, indirect damage such as traffic accident is mostly occurred in urban area. Therefore, the regional characteristics should be considered when vulnerability is evaluated. Therefore, in this study, the PSR and DPSIR method were applied by regional scale in South Korea. The PSR evaluation method is divided into pressure, state, and reaction index. however, the DPSIR evaluation method is divided into Driving force, Pressure, State, Impact, and Response index. the DPSIR evaluation method is divided into Driving force, Pressure, State, Impact, and Response index. Data corresponding to each indicator were collected, and the weight was calculated using the entropy method to calculate the snowfall vulnerability index by regional scale in South Korea. Calculated heavy snow damage vulnerabilities from the two methods were compared. The calculated vulnerabilities were validated using the recent snow damage in South Korea from 2018 to 2022. Snow vulnerability index calculated using the DPSIR method showed more reliable results. The results of this study could be utilized as an information to prepare the mitigation of heavy snow damage and to establish an efficient snow removal response system.