• Journal of Environmental Science International
• /
• v.27 no.3
• /
• pp.203-217
• /
• 2018

For this study, WRF numerical modeling was performed, using RDAPS information for input data on typhoons affecting the Korean peninsula to produce wind data of 700hPa. RAM numerical modeling was also used to calculate 3-second gusts as the extreme wind speed. After comparing wind speeds at an altitude of 10 m to evaluate the feasibility of WRF numerical modeling, modeled values were found to be similar with measured ones, reflecting change tendencies well. Therefore, the WRF numerical modeling results were verified. As a result of comparing and analyzing these wind speeds, as calculated through RAM numerical modeling, to evaluate applicability for disaster preparedness, change tendencies were observed to be similar between modeled and measured values. In particular, modeled values were slightly higher than measured ones, indicating applicability for the prevention of possible damage due to gales. Our analysis of 3-second gusts during the study period showed a high distribution of 3-second gusts in the southeast region of the Korean peninsula from 2002-2006. The frequency of 3-second gusts increased in the central north region of Korea as time progressed. Our analysis on the characteristics of 3-second gusts during years characterized by El $Ni{\tilde{n}}o$ or La Nina showed greater strength during hurricanes that affected the Korean peninsula in El $Ni{\tilde{n}}o$ years.

• 한국방재학회:학술대회논문집
• /
• 2008.02a
• /
• pp.109-112
• /
• 2008

The purpose of this study is to find out the characteristics of disasters caused by typhoons passing through the sea area around the Korean Peninsula. It analyzed two cases, that is, in WEST and EAST cases. These include the typhoons passing through the Yellow Sea, west of the Peninsula and East Sea, east of the Peninsula without landing on the Peninsula. FCM (Fuzzy Clustering Method) analysis was performed on typhoons affecting the Korean Peninsula from 1951 to 2006. The analysis shows that WEST case's cluster has the curved track of NE-S, and EAST case's cluster has the straight track of NE-SW. Typhoons that pass through the Yellow Sea have little change in frequency and the weak intensity. On the other hand, the frequency and the intensity of typhoons passing through the East Sea show the increasing trend. The characteristic of disasters by typhoons affecting the Korean Peninsula from 1973 to 2006 appears differently for each case: EAST cases caused significant damage in flooding, while WEST cases did damage in houses, ships, roads, and bridges. Rainfall amount and maximum wind speed data are analyzed in order to understand the impact of the typhoons, and the result indicates that the WEST cases are influenced by the wind, and East cases by precipitation. The result of this study indicates that the characteristic of disasters is distinctive according to the Typhoon's track. If applied to establish the disaster prevention plan, this result could make a contribution to the damage reduction.

• Journal of the Society of Naval Architects of Korea
• /
• v.43 no.1 s.145
• /
• pp.119-127
• /
• 2006

Recently as a result of excessive development. pollution of the coast and occurrence of a typhoon year after year, fishermen suffer heavy losses in fish farming which is the one of the most important earnings ways. For solution of these problems, we need to go out into the open sea from an inland sea. In this study we suggested new fish cage which makes up for the structural weakness of existing wooden fish cages. It can farm fishes in the open sea of high wave and current with no damages from a typhoon. We substituted TPU(Thermoplastic Polyurethane) air chamber for existing styrofoam flotage which was harmful to the environment and impermanent. We used PE(Polyethylene) pipes for the maintenance of formation and the prevention of buoyancy loss caused by a breakdown of flotage. PE b rackets were designed to combine PE pipes with TPU air-chamber flotage. It has good strength and light weight. As a result of modeling test. it is great in buoyancy, strength and flexibility against wave. Because it can control buoyancy arbitrarily, moreover, we expect that it will reduce damages of a red water by applying it as semi-submerged fish cages.

• Journal of Korea Multimedia Society
• /
• v.15 no.2
• /
• pp.258-265
• /
• 2012

Our country is suffering from many human victims and property damages caused to occur great and small tidal waves in southern areas every year. Even though there were progressing many researches for storm surges, it was required more researches for detection of tidal wave and prevention system of its which can be applied in practical living fields. In this paper, we propose the disaster prevention system that can approximately detect a dangerousness of coast flooding and number of overtopping per time based on images of CCTV considering actual field application. And if it is detected a hazard of flooding of coast, the proposed detection system for tidal wave based GIS is quickly informed the areas of flooding to manager. The analyzing results of CCTV image of this proposed are derived from difference images between photos of fine day and photos or videos which are taken for the typhoon which is called "DIANMU" at our laboratory.

• Journal of Korea Water Resources Association
• /
• v.53 no.7
• /
• pp.521-531
• /
• 2020

The purpose of this study is to suggest a quantitative assessment of wetland damage considering the effects of topsoil erosion and deposition from rainfall. In the Cheoncheon Basin located upstream of the Yongdam Dam, 16 wetlands are located, but the lacustrine and small palustrine wetland were analyzed for possible damage to erosion and deposition. As a result of applying typhoon events in 2002 and 2003, the sediment load from the upper basin was the highest at 2.30% (22,548 ㎥) of low water capacity. The average sediment load in the mountain areas was found to be 0.03% of the low water capacity, and it was analyzed to be less damaging than the lacustrine with relatively large watershed. as a result of the model, the lacustrine wetland, where a large area is used as agricultural land, shows a high probability of sediment yield, so it is highly likely to damage the wetland by topsoil erosion.

• Journal of Korean Society of Disaster and Security
• /
• v.14 no.1
• /
• pp.51-59
• /
• 2021

In Korea, where 64% of the soil is mountainous, typhoons and local rains concentrated in the summer season are frequent in mountainous disasters such as landslides and debris flow. The area of study was the area where the damage to the debris flow was caused by typhoon Mitag in October 2019, and all the houses located in the downstream area were damaged. In this study, numerical simulations were conducted on the area where the damage of earth and stone flow occurred using Hyper KANAKO model that can consider erosion and sedimentation, and the applicability of the model was examined by comparing the actual damage area and the analysis results of the model. As a result of the numerical simulation, the damage area of the debris flow in the target area was 53,875 m², the maximum flow depth was 2.4 m, and the average flow depth was 1.7 m.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.21 no.3
• /
• pp.241-253
• /
• 2009

This study performs the investigation of a long-term variation of annual maximum surge heights(AMSH) and main characteristics of high surge events, and the statistical evaluation of the AMSH using sea level data at Yeosu and Tongyeong tidal stations over more than 30 years. It is found that the long-term uptrends based on the linear regression in the AMSH are 34.5 cm/34 yr at Yeosu and 33.6 cm/31 yr at Tongyeong, which are relatively much higher than those at Sokcho and Mukho in the Eastern Coast. 71% and 68% of the AMSH occur during typhoon's event in Yeosu and Tongyeong tidal stations, respectively, and the highest surge records are mostly produced by the typhoon. The generalized extreme value distribution taking into account of the time variable is applied to detect time trend in annual maximum surge heights. In addition, Gumbel distribution is checked to find which one is best fitted to the data using likelihood ratio test. The return level and its 90% confidence interval are obtained for the statistical prediction of the future trend. The prevention of the growing storm surge damage by the intensified typhoon requires the steady analysis and prediction of the surge events associated with the climate change.

• Journal of Korean Society of Forest Science
• /
• v.77 no.3
• /
• pp.276-282
• /
• 1988

Many landslides occurred at the western part of Gyeongnam province by the typhoon No. 875. Their conditions and causes were investigated and were summarized as follows : The total number of landslide occurred was 2,490 and its area was 156.53ha. In about 94% of landslides and about 97% of landslides area occurred in 3 counties, Sancheong, Hamyang and Geochang. The landslides smaller than 0.01ha was 49% of the total indicating that about half of them were the small landslides. Considering homogenous topography amount of precipitation and forest type landslides appeared to be mainly has a high affected by the geological factor because the landslides mainly occurred in the deep weathered soil of igneous rock. The landslides occured on concave slopes of 31 to $35^{\circ}$ in steepness with low crown density. In the area of the deep weathered soil, landslide likely occur repeatedly. Therefore, regular erosion control works are recommended in the area of pos for disaster prevention and counter-measures.

• Korean Journal of Remote Sensing
• /
• v.37 no.5_3
• /
• pp.1435-1446
• /
• 2021

Wind and flood damage caused by typhoons causes a lot of damage to the Korean Peninsula every year. In order to minimize damage, a preliminary analysis of damage estimation and evacuation routes is required for rapid decision-making. This study attempted to develop an analysis module that can provide necessary information according to the disaster stage. For use in the preparation stage, A function to check past typhoon routes and past damage information similar to typhoon routes heading north, a function to extract isolated dangerous areas, and a function to extract reservoir collapse areas were developed. For use in the early stages of response and recovery, a function to extract the expected flooding range considering the current flooding depth, a function to analyze expected damage information on population, buildings, farmland, and a function to provide evacuation information were included. In addition, an automated web map creation method was proposed to express the analysis results. The analysis function was developed and modularized based on Python open source, and the web display function was implemented based on JavaScript. The tools developed in this study are expected to be efficiently used for rapid decision-making in the early stages of monitoring against storm and flood damage.

• Journal of Korea Water Resources Association
• /
• v.46 no.6
• /
• pp.655-666
• /
• 2013

Lately, intensity and frequency of natural disasters such as flood are increasing because of abnormal climate. Casualties and property damages due to large-scale floods such as Typhoon Rusa in 2002 and Typhoon Maemi in 2003 rapidly increased, and these show the limits of the existing disaster prevention measures and flood forecasting systems regarding irregular climate changes. In order to efficiently respond to extraordinary flood, it is important to provide effective countermeasures through an inundation model that can accurately simulate flood inundation patterns. However, the existing flood inundation analysis model has problems such as excessive take of analysis time and accuracy of the analyzed results. Therefore, this study conducted a flood inundation analysis by using the Gerris flow solver that uses quadtree grid, targeting the Baeksan Levee in the Nakdong River Basin that collapsed because of a concentrated torrential rainfall in August, 2002. Through comparisons with the FLUMEN model that uses unstructured grid among the existing flood inundation models and the actual flooded areas, it determined the applicability and efficiency of the quadtree grid-based flood inundation model of the Gerris flow solver.