• Journal of the Korean Association of Geographic Information Studies
• /
• v.19 no.4
• /
• pp.17-35
• /
• 2016

Earthquake-induced disasters are often more severe in locations with soft soils than firm soils or rocks due to differences in ground motion amplification. On a regional scale, such differences can be estimated by spatially predicting subsurface soil thickness over the entire target area. In general, soil deposits are generally deeper in coastal or riverside areas than in inland regions. In this study, a coastal metropolitan area, Incheon, was selected to assess site effects and provide information on seismic hazards. Spatial prediction of geotechnical layers was performed for the entire study area within the GIS framework. Approximately 7,000 existing borehole drilling data in the Incheon area were gathered and archived into the GIS Database (DB). In addition, surface geotechnical data were acquired from a walkover survey. Based on the built geotechnical DB, spatial zoning maps of site-specific seismic response parameters were created and presented for use in a regional seismic strategy. Site response parameters were performed to determine site coefficients for seismic design over the entire target area and compared with each other. Site classifications and subsequent seismic zoning were assigned based on site coefficients. From this seismic zonation case study in Incheon, we verified that geotechnical GIS-DB can create spatial zoning maps of site-specific seismic response parameters that are useful for seismic hazard mitigation particularly in coastal metropolitan areas.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2022.05a
• /
• pp.329-329
• /
• 2022

Accurate characterization of terrestrial precipitation variation from high spatial resolution satellite sensors is beneficial for urban hydrology and microscale agriculture modeling, as well as natural disasters (e.g., urban flooding) early warning. However, the widely-used top-down approach for precipitation retrieval from microwave satellites is limited in several hydrological and agricultural applications due to their coarse spatial resolution. In this research, we aim to apply a novel bottom-up method, the parameterized SM2RAIN, where precipitation can be estimated from soil moisture signals based on an inversion of water balance model, to generate high spatial resolution terrestrial precipitation estimates at 0.01º grid (roughly 1-km) from the C-band SAR Sentinel-1. This product was then tested against a common reanalysis-based precipitation data and a domestic rain gauge network from the Korean Meteorological Administration (KMA) over central South Korea, since a clear difference between climatic types (coasts and mainlands) and land covers (croplands and mixed forests) was reported in this area. The results showed that seasonal precipitation variability strongly affected the SM2RAIN performances, and the product derived from separated parameters (rainy and non-rainy seasons) outperformed that estimated considering the entire year. In addition, the product retrieved over the mainland mixed forest region showed slightly superior performance compared to that over the coastal cropland region, suggesting that the 6-day time resolution of S1 data is suitable for capturing the stable precipitation pattern in mainland mixed forests rather than the highly variable precipitation pattern in coastal croplands. Future studies suggest comparing this product to the traditional top-down products, as well as evaluating their integration for enhancing high spatial resolution precipitation over entire South Korea.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.10a
• /
• pp.278-287
• /
• 2000

In Korea, countermeasures against earthquake disasters such as the seismic performance evaluation and/or retrofit scheme of buildings have not been fully performed since Korea had not been experienced many destructive earthquakes in the past. However, due to more than four hundred earthquakes with slight/medium intensity occurred in the off-coastal and inland of Korea during the past 20 years, and due to the great earthquakes occurred recently in neighboring countries, such as the 1995 Hyogoken-Nambu Earthquake with more than 6,500 fatalities in Japan and the 1999 Ji-Ji Earthquake with more than 2,500 fatalities in Taiwan, the importance of the future earthquake preparedness measures in Korea is highly recognized. The main objective of this paper is to provide the basic data for development of a methodology for the future earthquake preparedness in Korea by investigating the concept and applicabilities of the Japanese Standard for Evaluation of Seismic Performance of Existing RC Buildings developed in Japan among the methodologies of all over the world. In this paper, a seismic performance evaluation method of the existing reinforced concrete buildings is proposed based on experimental data of columns and walls carried out in Korea by referring the Japanese Standard, especially focusing on the Strength Index(C) among the indices in the seismic capacity index(IS) equations. Also, the seismic capacities of two existing reinforced concrete buildings in Korea are evaluated based on the proposed methodology and the Japanese Standard, and the correlations between the seismic capacities by the proposed methodology and the Japanese Standard are discussed.

• Journal of Ecology and Environment
• /
• v.38 no.2
• /
• pp.263-269
• /
• 2015

When we consider changes in agro-fishery systems instigated by environmental changes in islands, rise in sea levels, and natural disasters such as tsunamis, there is an urgent need to carry out initiatives to enhance life standard and conserve ecosystem in island and coastal regions. To protect the region's landscape from the effects of climate change, it is necessary to develop an integrated management system for ecosystem conservation, human settlements, and the local economy. This paper discusses the outline of a preliminary national plan for a sustainable island management system for remote (inhabited and uninhabited) islands in Korea. Two main ideas to enhance life standard are adapting to the natural environment by applying traditional knowledge and utilizing ecological resources of islands, i.e., improving the quality of life and creating added value. As a technique for improving the quality of life, the establishment of eco-villages based on energy-efficient passive houses and ecological welfare is suggested. Another technique for creating added value, the development of sea-farming islands that utilize islands' new recyclable energy is also proposed. Finally, the suggested ideas are discussed in relation to island ecotourism and carbon zero islands.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.10a
• /
• pp.995-998
• /
• 2007

It is essential to establish some systematic counterplans to diminish such damages of large-scale tidal invasion on coastal lowlands considering the recent weather conditions of growing scale of typhoons. Therefore, the purpose of this research is to make the counterplans for prevention against disasters fulfilled effectively based on the data conducted by comparing and analyzing the accuracy between observation values and the results of estimating the greatest overflow area according to abnormal tidal levels centered on Masan area where there was the severest damage from tidal wave at that time.

• Journal of Navigation and Port Research
• /
• v.42 no.6
• /
• pp.518-528
• /
• 2018

Unlike in the past, port space in modern society not only serves to meet port functions but also other functions such as housing, leisure, and sightseeing. As a result, more and more people are turning into a dense space. Port space, on the other hand, is also a space vulnerable to disasters which can be attributed to geographical and environmental characteristics. Despite the sensitivity if the issue, in Korea disaster prevention and urban planning have not been clearly established. Therefore, there is a need to provide safety and disaster preventive measures in urban planning considering the characteristics of harbor space.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.293-293
• /
• 2020

기후변화로 인해 다양한 재난이 복합적으로 발생하고 있으며, 특히 해안과 인접해 있는 지역은 풍랑, 지진해일 등으로 인해 다양한 위험에 노출되어 있는 실정이다. 이에 따라 각 지자체는 자연재해대책법에 의거하여 자연재해저감종합계획을 수립하고 저감대책을 마련하고 있으나, 수립 절차에 따른 비용과 시간이 많이 소요되고 있다. 따라서 위험지역의 지리적·사회적 조건을 고려한 맞춤형 재해예방기법 도출방안이 필요하다. 이에 본 연구에서는 과거 피해이력과 침수예상도 정보가 반영된 위험성평가 지도를 활용하여 위험지역 유형을 4단계(관심, 주의, 경계, 위험)로 구분하고, 단계별 구조물적 대책과 비구조물 대책의 적용방안을 제시하였으며, 구조물적 대책과 비구조물적 대책의 도출에는 지역맞춤형 요소와 특성요소를 활용하였다. 지역맞춤형 요소는 자연인자, 재해영향인자, 재해원인인자, 지형인자, 사회인자로 구분하였으며, 각 인자별로 세부인자를 선택하여 논리연산에 따라 재해예방기법을 도출하였다. 특성요소는 효율성, 시공성, 공공성으로 구분하였고, 각 구분별 세부요소를 평가하여 재해예방기법의 우선순위를 도출하였다. 본 연구를 통해 향후 해안가 복합재난이 예상되는 지역을 대상으로 지역맞춤형 재해예방기법을 도출할 수 있을 것이며, 자연재해저감종합계획 수립 시에도 활용할 수 있을 것으로 기대된다.

• Journal of Ocean Engineering and Technology
• /
• v.38 no.3
• /
• pp.103-114
• /
• 2024

Remote sensing wave observation data are crucial when analyzing ocean waves, the main external force of coastal disasters. Nevertheless, it has limitations in accuracy when used in low-wind environments. Therefore, this study collected the raw data from MIROS Wave and Current Radar (MWR) and wave radar at the Ieodo Ocean Research Station (IORS) and applied the optimal filter by combining filters provided by MIROS software. The data were validated by a comparison with South Jeju ocean buoy data. The results showed it maintained accuracy for significant wave height, but errors were observed in significant wave periods and extreme waves. Hence, this study used an artificial neural network (ANN) to improve these errors. The ANN was generalized by separating the data into training and test datasets through stratified sampling, and the optimal model structure was derived by adjusting the hyperparameters. The application of ANN effectively improved the accuracy in significant wave periods and high wave conditions. Consequently, this study reproduced past wave data by enhancing the reliability of the MWR, contributing to understanding wave generation and propagation in storm conditions, and improving the accuracy of wave prediction. On the other hand, errors persisted under high wave conditions because of wave shadow effects, necessitating more data collection and future research.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.7
• /
• pp.760-769
• /
• 2023

A numerical simulations were performed to investigate the storm surge during the passage of Typhoon Maemi on the coast of Busan. The typhoon landed on the southern coasts of Korean Peninsula at 21:00, September 12, 2003 with a central pressure of 950 hPa, and the typhoon resulted on the worst coastal disaster on the coast of Busan in the last decades. Observed storm surges at Busan, Yeosu, Tongyoung, Masan, Jeju and Seogwipo harbors during the passage of the typhoon were compared with the computed data. The simulated storm surge time series were in good agreement with the observations. The simulated peak storm surges were estimated to be 230 cm at Masan harbor, 200 cm at Yeosu harbor and Tongyoung harbor, and 75 cm at Busan harbor. The computed storm surges along the east coast of Busan measure 52 to 55 cm, exhibiting a gradual reduction in surge height as one moves further from the coast of Busan. Therefore, coastal inundation due to the storm surge in the semi-enclosed bay can induce great disasters, and the simulated results can be used as the important data to reduce the impact of a typhoon-induced coastal disaster in the future.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.5
• /
• pp.506-513
• /
• 2020

Due to climate change, there is an increasing risk of complex (hybrid) disasters, comprising rising sea-levels, typhoons, and torrential rains. This study focuses on Marine City, Busan, a new residential city built on a former landfill site in Suyeong Bay, which recently suffered massive flood damage following a combination of typhoons, storm surges, and wave overtopping and run-up. Preparations for similar complex disasters in future will depend on risk impact assessment and prioritization to establish appropriate countermeasures. A framework was first developed for this study, followed by the collection of data on flood prediction and socioeconomic risk factors. Five socioeconomic risk factors were identified: (1) population density, (2) basement accommodation, (3) building density and design, (4) design of sidewalks, and (5) design of roads. For each factor, absolute criteria were determined with which to assess their level of risk, while expert surveys were consulted to weight each factor. The results were classified into four levels and the risk level was calculated according to the sea-level rise predictions for the year 2100 and a 100-year return period for storm surge and rainfall: Attention 43 %, Caution 24 %, Alert 21 %, and Danger 11 %. Finally, each level, indicated by a different color, was depicted on a complex disaster risk map.