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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Korean Society of Hazard Mitigation
Journal Basic Information
Journal DOI :
Korean Society of Hazard Mitigation
Editor in Chief :
Moo Jong Park
Volume & Issues
Volume 15, Issue 6 - Dec 2015
Volume 15, Issue 5 - Oct 2015
Volume 15, Issue 4 - Aug 2015
Volume 15, Issue 3 - Jun 2015
Volume 15, Issue 2 - Apr 2015
Volume 15, Issue 1 - Feb 2015
Selecting the target year
Collapse Accident Factors of Pangyo vents by Analyzing AHP
Yang, Ginam ; Kim, Gwang-Hee ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 1~8
DOI : 10.9798/KOSHAM.2015.15.6.1
Collapses of building structures or facilities have been frequently reported in recent years. A structural collapse can cost many people's lives. Mauna Ocean Resort Collapse and Pangyo Techno Valley Vents Collapse are key examples of this kind of incident. In the former, 10 people lost their lives, while 16 people were killed in the latter incident. However, there have been few studies to analyze the causes of these recently reported disasters. In this study, each of the accident factors of the Pangyo Techno Valley Vents Collapse was quantitatively analyzed by using a hierarchical analysis method. In the analysis result, faulty construction items including construction factor and inspection negligence in the construction process were evaluated to have a higher priority. It is expected that the findings of this research can be utilized as fundamental data to prevent a structural collapse.
Review on Evaluation of Ground Snow Load through Building Collapse Cases
Lee, Youngkyu ; Lee, Chuljoo ; Kim, Jinho ; Yu, Insang ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 9~17
DOI : 10.9798/KOSHAM.2015.15.6.9
In the study we estimate the snow loads at building collapse accidents based on the snow depths, precipitation and wind speeds gaged at the closest station. CSL (Conservative Snow Load) is the load evaluated on the assumption that the freshly fallen snow accumulates without melting when it snows day by day. We compare the CSLs at accidents and the GSLs (ground snow load announced by Korean government), and the unit weights at accidents and the snowpack unit weight formula used to estimate GSL. The accidents have occurred frequently near East Sea coast and the unit weights at the accidents are considerably greater than the snowpack unit weight formula. Especially the building collapses in Ulsan and Busan which have comparatively warm winter seasons are caused by highly water content wet snows. The snowpack unit weight formula developed on the assumption of low air temperature would not proper to Korean climate. Development of a new snowpack unit weight formula, therefore, needs for safety Korea.
Optimization of Locations of Elevated Tanks for Stable Water Supply Networks
Park, Yonggyun ; Jung, Sunggyun ; Yoo, Doguen ; Jun, Hwandon ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 19~26
DOI : 10.9798/KOSHAM.2015.15.6.19
Providing customers with the desirable amount of water with sufficient pressure is the most critical issue in operating a water supply network. It is possible to secure the necessary amount of water for stable operation by taking water from a reservoir or a dam, whereas supplying water with sufficient pressure stably is determined by how they properly design and operate a water supply network. In cases of mountainous areas such as Korea or where customers are widely distributed, too much pressure head loss in conveying water makes it difficult to maintain the design pressure head at demand locations. Usually, the utility resolves this problem by introducing a booster pump to the system. Besides booster pumps, another alternative will be an elevated tank for the system. It is, however, important to determine the number and locations of elevated tanks for obtaining the maximum advantages by installing an elevated tank. In this study, we suggest a methodology for determining the number and locations of elevated tanks by the quantification of being pressure-stable. The advantage obtained by elevated tank combinations is quantified in terms of "the number of pressure-improved nodes" and "Index of pressure improvement"and the methodology is applied to a sample network to prove its applicability.
Early Warning Model using Case-Based Reasoning for Construction Site Safety Accidents
Shin, Yoonseok ; Yoo, Wi Sung ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 27~33
DOI : 10.9798/KOSHAM.2015.15.6.27
In these days, the accidents on construction site are continuously increasing in spite of the managerial efforts and financial investments. This trend encourage safety managers or decision makers to enhance existing approaches and to develop innovative and proactive management aids. In this study, we propose an early warning model, called the Early Warning Model (hereafter EWM), for the potential types and causes of an accident as a project is progressive, using Case-Based Reasoning technique. The EWM was tested with illustrative cases, and the results showed a few possible cases with high likelihood for a specific situation randomly selected in the construction field. It is expected that the EWM is useful for furnishing safety managers and field supervisors with warning signals during the construction and helpful for assisting them in responding preactively and minimizing the ripple effect of construction site accidents.
Construction Evaluation on the Form Deck System for Continuos Methods and Laterally Trussed Girder
Kim, Young Ho ; Choi, Sung Mo ; Lee, Seong Hui ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 35~42
DOI : 10.9798/KOSHAM.2015.15.6.35
Slim floor system is a method for the pouring concrete after a steel formed deep deck placed on the bottom flange of steel H-beam. Recently As the demand for long span building to secure a parking area increases, the need for development of a long span deep deck without support has emerged. Accordingly, in this study, we proposed improvements to develop of form deep deck applicable to 7.5 m(net length=7.2 m) without supports, then sand loading experimental tests for six specimens were planned to verify the effect on parameters of the end continuity of spans, methods of the end continuity(rebar or cap plate), the thickness of cap plates, lateral trussed girders.
Evaluation of Shear Strength of Non-prestressed Reinforced Concrete Hollow-Core Slabs
Eom, Tae-Sung ; Hwang, In-Hye ; Park, Tae-Won ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 43~54
DOI : 10.9798/KOSHAM.2015.15.6.43
In Korea, non-prestressed reinforced concrete hollow-core slab construction method has been developed and used in construction fields. Provisions for the shear strength of hollow-core slabs based on the effective width of web (
), which are specified in current design codes, are too conservative and cannot consider accurately the effects of properties of hollow cores. In this study, the shear performance of one-way RC hollow-core slabs was investigated. Two-point loading simple beam tests were performed for ten hollow-core slabs with a thickness of 300 mm and a width of 600 mm, designed to fail in shear or flexure. Results showed that the shear strength of hollow-core slab was degraded as the void ratio increased but hardly affected by other factors including the effective width of web. Shear strengths of the hollow-core slabs estimated by KCI 2012, ACI 318-11, Eurocode 2, and CSA A23.05 were compared with the test strengths. In addition, based on the test observations, the shear resistance of the hollow-core slabs was estimated by using the shear-tension failure theory for the concrete compression zone subjected to biaxial plane stresses.
Experimental Comparative Study on Devices Measuring Field Moisture Content of Roadbed Materials
Lee, Sang Ick ; Oh, Jeongho ; Sebesta, S.D. ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 55~64
DOI : 10.9798/KOSHAM.2015.15.6.55
For in-place moisture content measurements as a part of quality control (QC) of roadbed construction, many agencies rely on nuclear testing and physical gravimetric drying for moisture content measurements. In this study, alternative methods were initially evaluated to identify technologies that could be used to measure moisture content in the field substitute using gravimetric, dielectric, and electrical conductivity, and suction-based methods. The small scale field test and actual field tests were then performed to evaluate device bias and accuracy, and estimates of single-operator standard deviation of repeat measurements. Through those results, the list of most promising devices could be narrowed down.
Track-bridge Longitudinal Interaction Response Analysis Considering the Variation of Temperature
Kwon, Ohhyuk ; Yun, Kyungmin ; Park, Beomho ; Jeon, Byeongheun ; Lim, Namhyoung ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 65~71
DOI : 10.9798/KOSHAM.2015.15.6.65
When a continuous welded rail(CWR) track is supported by bridge, additional axial stress and displacement are occurred by track-bridge interaction, and they have an effect on safety and serviceability of track. Domestic and foreign standards for track-bridge interaction offer analysis methods and limit values which are guiding the safety design, because the influence on interaction is difficult to be evaluated quantitatively. In this study, measurement system was constructed on the concrete a track supported by a bridge, and field monitoring has been carried out to evaluate the influence on track-bridge interaction by temperature changes. And track-bridge interaction responses under various temperatures were analyzed by comparing results of measurement and numerical analysis.
Hydration Heat of Ultra-High-Strength Concrete Column According to Cross Sectional Shape
Lee, Sang Kyu ; Lee, Joo Ha ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 73~78
DOI : 10.9798/KOSHAM.2015.15.6.73
Study on ultra-high-strength concrete(UHSC) has increased since it is essential in skyscraper construction. Since UHSC mixture has a large amount of the cementitious materials, UHSC can be applied on-site only when its thermal crack behavior due to heat of hydration is evaluated and controlled. In this study, finite element analysis using adiabatic temperature rise test data of UHSC was performed to evaluate thermal crack of UHSC columns. By modeling of circular and square UHSC columns, the characteristics of hydration heat, thermal stress, and thermal crack ratio were investigated according to column shape. As a result, it was confirmed that circular columns are more effective in thermal crack resistance than the square column.
Feasibility Study of Smart Sensing Technology for Tram by Using Small Scale Experiment
Moon, Jiho ; Kim, Jeongguk ; Seo, Sung-il ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 79~85
DOI : 10.9798/KOSHAM.2015.15.6.79
The roads in metro cities are very congested and interest in tram system has been increased as an alternative of new roads or metro construction, since heavy cost is expected to construct them. However, tram is always exposed to accident, since the tram share the roads with vehicles. Thus, it is important to enhance the safety of the tram for successful introduction of it. In this study, new 'smart sensing tram' was proposed to enhance the safety of the tram, and small scale model was developed. Several sensing technologies were used to detect the environmental factors, such as signal and obstacle around the tram, and control the tram. The performance of the proposed tram was verified by using the small scale experiments. From the results, reliable results can be obtained for signal and obstacle detection in the tests. For practical use of the proposed tram, it in necessary to investigate the performance of the tram in various environments as well as the tests in real scale tram.
Analysis of Soil Stiffness Variation in Case of Cavity Generation in Underground below Subway Track using Light Weight Deflectometer
Lim, Yujin ; Cho, Hojin ; Jung, Yeong Nam ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 87~99
DOI : 10.9798/KOSHAM.2015.15.6.87
Cavities have been found many times recently in downtown of metropolitan area due to old and damaged utility pipes installed in the ground long time ago. The cavities are generated by spilling out of flowing water from the pipes mostly. The cavities generated below subway track can induce irregularities and unstabilities to the track. In this study, a finite element program ABAQUS is used to analyze stress and deflection spectrum in order to get soil modulus by simulating LWD test applied to the ground with cavity. It is found from the FE analysis of LWD test that the LWD test can be used effectively to check out cavity existence below subway track by checking modulus variation of the ground.
Investigation of Urban Flooding Characteristics due to Heavy Summer Rainfall in Seoul using GIS
Jin, Ri ; Yoo, Jae-yong ; Lee, Kyoo-seock ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 101~108
DOI : 10.9798/KOSHAM.2015.15.6.101
The urban flood occurs frequently due to the heavy summer rainfall by climate change and the intensification of urban heat island caused by increase in the emission of anthropogenic heat in urban area. The damage in urban area is more disastrous than that of rural area due to the concentration of population and facilities. In particular, Daechi station flooding and Woomyeon Mountain landslide by heavy rainfall occurred on July 27, 2011 which showed the seriousness of the urban flooding with life death and property damage. Therefore, the purpose of this study is to investigate the urban flooding characteristics by analyzing meteorological, topographical and land use characteristics of Daechi Station Flooding on July 27, 2011. GIS sewer-network analysis was used in this study to investigate the flooding point. After implementing this study the following conclusions were derived. (1) The topography of the study site is lower than the surrounding area and the water is collected at the study site as a basin. (2) The rainfall intensity was 92mm/hr at that time, which showed the typical heavy urban rainfall. (3) 70% of the surface in the study site was paved with impervious materials and runoff coefficient is 0.95, so the peak discharge rate is
, the maximum drainage capacity of drainage pipe, which resulted in urban flooding. (4). The flooding occurred at branch pipe, not main pipe. So these flooding characteristics should be considered in the future disaster prevention planning.
Inundation Analysis of Ground and Underground Spaces in Urban Areas
Choi, Ji-Hyeok ; Hwang, Sung-Hwan ; Kim, Jong-Suk ; Moon, Young-Il ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 109~117
DOI : 10.9798/KOSHAM.2015.15.6.109
As the population is concentrated in a city, the number of complex buildings such as skyscrapers and underground facilities has increased. Moreover, complicated underground spaces with multi-story, not one-story have been increasingly used. Therefore, it is urgent to analyze underground flooding and make a plan for prevention from the flooding. For this reason, this study set an expected height of underground flooding from the inflow water toward underground with a study target of underground complex buildings with crowded underground stores and parking lots. In addition, through flooding analysis on scenarios, this study suggested proper capacity for the storage and pump facilities. Moreover, this study conducted a comprehensive analysis on flooding process and depth on scenarios to suggest a standard for flooding prevention by building types when designing an underground complex building.
Improvement of the Effect of a Reservoir System Simulation Under Floods for the Han River Basin by an Optimization Technique
Kang, Taeuk ; Lee, Sangho ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 119~127
DOI : 10.9798/KOSHAM.2015.15.6.119
A reservoir simulation operation method is used more frequently than an optimal operation method because the simulation method is more flexible enough to reflect sudden changes of practical flood conditions or the intuitions and experience of dam operators. However, the results from a reservoir simulation operation model vary according to input control data. Thus, it is required to choose appropriate input control data of the reservoir simulation operation model through repetitive preliminary simulations. The purpose of the study is to derive optimal input control data of the reservoir simulation operation model by an optimization technique, and to improve effect of flood control. The shuffled complex evolution algorithm was used to optimize input control data of the model, which are initiation time of spillway release and release quantity. The reservoir simulation operation model and optimization technique was applied to a rainfall event in September 1990 when it rained a lot in the Han River Basin and showed the better flood control effects.
A Study for Flood Control of a Dam Using Flood Guide Curves and Release Determination Method in Accordance with Reservoir Water Level
Kang, Taeuk ; Lee, Sangjin ; Kang, Shinuk ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 129~136
DOI : 10.9798/KOSHAM.2015.15.6.129
Most of dams are located in mountainous area where slope of catchment and stream is very steep. Especially, effective flood control by a dam can't be achieved if there are difficulties in predicting flood by geomorphological effect or restrictions for upstream and downstream of a dam. This study proposed flood guide curves for effective flood control and intuitive response to real time flood in a dam. Release determination method in accordance with reservoir water level was also introduced to apply the flood guide curves to real time practice. Validity of the flood guide curves and release determination method was evaluated by applying them to several previous flood events. The flood guide curves and release determination method can be used in real time flood control of a dam in future.
Development of Rainfall-Runoff Reduction Facilities for Operation and Analysis System Prototype
Kang, Minsuk ; Oh, Kukryul ; Yang, Dongmin ; Jung, Dojun ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 137~145
DOI : 10.9798/KOSHAM.2015.15.6.137
Recently, urbanization had caused an increase in the imperviousness on an area of land and due to climate change, torrential rain frequently occurs everywhere. As a result, the urban flood damages vastly increased. Countries have created a reduction measures for minimizing damage through the use of a rainfall-runoff reduction facilities. However, the standard system and quantitative analysis of the facility for setting the position is insufficient. Therefore, this study tries to develop an analysis of the position selection and effects of rainfall-runoff reduction facilities systematically. Investigation of the trends related to the study of urban rainfall-runoff model for system development, setting the application of SWMM model to derive the direction and function of development and collating of required data to create a flow chart as a design for the overall flow of the system is needed, to developed a Data Base design and prototype. A Prototype system was considered for the convenience of users, which constitutes to a GIS. Through the system's facility arrangement, it is possible to know the result of the analysis of runoff, thereby reducing the size calculations. Allowing this user decision support functions for further development in the future can make it more useful and effective.
A Study on the Rate Making Method Based on Insurable Value and Loss Cost of Each Zone(Inundation Depth)
Lee, Heechun ; Lim, Hyuntaek ; Kim, Donggyun ; Kim, Yongtae ; Lee, Junseok ; Kim, Yongseong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 147~157
DOI : 10.9798/KOSHAM.2015.15.6.147
Generally, the rate making is made by the fundamental principle that it should be fairly differentiated in accordance with risk magnitude of insured objects. But the natural insurance is currently rated by city, country and district, which are recognized as rating units and it does not provide any reasonable discriminatory based on risk magnitude. Therefore, only those who possess the high-risked objects of insurance are strongly likely to be insured and it may also cause the problem of adverse-selection. To solve this problem, the single rate of current city, county and district is specified by six zones, depending on the size of inundation depth, as the homogeneous risk. It then suggests another way of calculating the rate making by using insurable value and loss cost of the zonal object of insurance. Then this study applied this method into calculating the zonal rates of Buk-Gu of Ulsan metropolitan city, and so on. Through making a comparison single rate with zonal rate, we confirmed the actual applicability of using this study.
A Basic Research for the Development of Cultural Heritage Disaster Safety Management System - Focusing on the Typology of Management Targets and Analysis of the Damage Pattern -
Cho, Hong-Seok ; Suh, Hyun-Jung ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 159~168
DOI : 10.9798/KOSHAM.2015.15.6.159
With a view to constructing an efficient and systematic disaster safety management system for cultural heritage, this study has established the concepts of cultural heritage management system in terms of disaster management and analyzed the damage patterns through classifying the targets of the management. Specifically, based on various literature and regulations concerning the matters, we provided definitions of various terms and laid a theoretical basis for system development by reestablishing the concepts regarding cultural heritage disaster safety management and disaster safety management system.
Improvement and Problems of the Greenhouse(Vinyl Greenhouse) Insurance Rates System
Lee, Heechun ; Lim, Hyuntaek ; Kim, Donggyun ; Kim, Yongtae ; Kim, Jungsoo ; Kim, Yongseong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 169~178
DOI : 10.9798/KOSHAM.2015.15.6.169
Generally, it is a fundamental principle of the rate making which should be fairly discriminatory in accordance with risk level of insured objects. However, the current greenhouse(vinyl greenhouse) insurance is estimated and applied by a single rate of current city, county and district unit and it is not fairly discriminatory by the risk level of greenhouse(vinyl greenhouse). In this case, only farmers who possess the high-risk greenhouse(vinyl greenhouse) are likely to be insured and it may cause an adverse selection problem. Therefore, this study classified the current single rate of city, county and district into four rating units, depending on the degree of risk of greenhouse(vinyl greenhouse) and also calculated a mean damage ratio in each class. It suggested a differentiated rate method, applying the calculated mean damage ratio. As using the method in this study, it calculated rates of Andong-si, Gyeongsangbuk-do and four other city, county and district units. It confirmed the actual applicability of the method through making a comparison analysis of the single rate.
Disaster Classification for Optimal Disaster Response in Korea
Kim, Yongkyun ; Jang, Hyoseon ; Choi, Yoonjo ; Sohn, Hong-Gyoo ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 179~188
DOI : 10.9798/KOSHAM.2015.15.6.179
Global loss due to disasters has been sharply increasing in conjunction with intensifying disaster complexity and magnitude. In the last decade, the Republic of Korea has also suffered a large number of casualties, uncountable physical damages and severe economic loss caused by various disasters. In particular, social disasters have been rapidly escalating. A series of recent social disasters, such as the Hydrofluoric Acid Leakage at the Gumi Chemical Plant in 2013 and the Mauna Resort Collapse in Gyeongju and the Sewol Ferry Accident in 2014, show that the current disaster classification system, developed on the basis of hazard type, is neither comprehensive enough to deal with recently emerging disasters' increased complexity and amplified magnitude, nor adequate enough to improve the disaster response system. Therefore, there is a critical need to develop a new disaster classification system that bears in mind disaster characteristics and the role of disaster response organizations. This research analyzed major disasters in the last decade, focusing on what types and patterns of disaster damage occurred; how quickly disasters precipitated damage; and when and how Central Disaster and Safety Countermeasures Headquarters and Central Disaster Management Headquarters operated according to their roles. As a result, this paper proposed a new disaster classification system that can serve to lay the foundation for developing an advanced disaster response system, which takes the characteristics of various disasters into account.
A Study on Statistical Methods for the Development of Flash Flood Index
Yoon, Sanghoo ; Choi, Sumin ; Lee, Byung Ju ; Choi, YoungJean ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 189~197
DOI : 10.9798/KOSHAM.2015.15.6.189
Flash flood prevention system is necessary because local torrential heavy rain during short time causes the damage of human life and property. This study is dealt with the assessment of flash flood based on the reported flash flood casualty accident data between 2009 and 2012, and hydrometeorologic information generated by land surface model (TOPLATS). The past six hour data of soil moisture condition, surface runoff amount, rainfall amount from high potential flash flood time are reconstructed by factor analysis. A flash flood index is developed through a linear regression model and a linear combination of weighted hydrometeorological factors. The flash flood index is sensitive to short-term hydrometeorologic outputs and the frequency of flash flood alarm is minimized through optimization.
Evaluation on the Application of the Estimation of Time of Concentration Using Real Rainfall-Runoff Events in Small Forest Watershed
Kim, Jaehoon ; Choi, Hyung Tae ; Lim, Hong-geun ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 199~206
DOI : 10.9798/KOSHAM.2015.15.6.199
This study was carried to figure out appropriate method for time of concentration used in the Rational method at design flood estimation. For 6 small forest watershed, time of concentration was obtained from time of concentration formulas including Kirpich Rziha, Kraven (I), Kraven (II) and SCS lag method and the results from these were compared to the results from cross correlation function based on real rainfall runoff events. The results of cross correlation function ranged from 12.9 to 28.8 minutes and the average difference between SCS lag method and cross correlation function was 2.5 minutes. SCS lag method would be feasible to estimate time of concentration in small forest watershed.
Two-dimensional Numerical Analysis for Debris Flows at Jecheon
Jun, Byonghee ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 207~212
DOI : 10.9798/KOSHAM.2015.15.6.207
In this study, the topographical changes associated with erosion and deposition by intensive rainfall and the consequential debris flow were evaluated using terrestrial LiDAR (Light Detection And Ranging). The intensive rainfall over 400 mm occurred between on 9 to 14 July 2009 triggered debris flows around the mountain area in Jecheon County. Three major rainfall events occurred in six days with a short interval and the sequence of debris flow events in the study area started on 14 July 2009 during the third rainfall peak which scored the maximum rainfall intensity of 64 mm/h and 201 mm/d. The LiDAR data allowed comprehensive investigation of the morphological features present along the sliding surface and in the deposit areas. The DEM derived from the LiDAR enabled the debris flow to be mapped and analyzed in great detail. The erosion/deposition volume were estimated to
, respectively. The flooding area and erosion/deposition volumes by debris flow were compared with numerical simulation results. The simulation results had sufficiently good agreement with the debris flow track, and a success rate of 65% in affected area was achieved with a simulation time of 250 s. A comparison of the simulated and surveyed results based on deposition volume yields a success rate of over 97% with 350 s of simulation time.
Construction and Operation of the National Landslide Forecast System Using Soil Water Index in Republic of Korea
Lee, Changwoo ; Kim, Dongyeob ; Woo, Choongshik ; Kim, You Seung ; Seo, Junpyo ; Kwon, Hyunjung ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 213~221
DOI : 10.9798/KOSHAM.2015.15.6.213
The objective of this study was to describe the background and methodology of the current operational national landslide forecast system in Republic of Korea and analyze its operational results in the past two years. Soil water index and tank model were employed as the national landslide forecast system with a goal of pre-1-hour forecast for landslide likelihood in a national scale. The tank model was parameterized with the past rainfall data inducing landslides in each divided eleven region after considering rainfall and geological characteristics in the whole country. The national landslide forecast system have provided local administrations with the information of predicted warnings calculated with observed and predicted rainfall data by Korea Weather Administration in a hour since 2013, and they issue landslide warnings including landslide watch and alert based on the information. As results of its two-year-operation, 420 and 248 predicted warnings were calculated in 2013 and 2014, respectively. But, 33 of 420 in 2013 and 17 of 248 in 2014 were not finally issued in reality, accounting for 7.9% and 6.9%, respectively. Also, predicted warnings were not calculated for 36 of 72 landslides occurred in 2014 compared to only one out of 212 landslides in 2013. Overall, improvement of input rainfall data accuracy, regular revision of tank model parameters, and relevant adjustment of landslide warning issuing level were suggested to improve the efficiency of the national landslide forecast system.
Assessment of Physical Properties and Fire Suppression Ability of Wildfire Foam
Kim, Donghyun ; Lee, Jihee ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 223~229
DOI : 10.9798/KOSHAM.2015.15.6.223
Assessment of wildfire agents should consider their physical properties and effects on chemical composition and fire suppression ability. In this study, five candidate foam agents most widely used in the USA (2 Foams), South Korea (2 Foams), and Japan (1 Foam) were evaluated according to: 1) physical properties, such as pH, viscosity, freezing, ignition, specific gravity, surface tension, foam properties, metal corrosion, and accelerated aging; and 2) suppression ability, measured as the time and amount of chemical needed to extinguish a fire. From this analysis, we found that Miracle Foam hardened to a solid state during the test of physical properties and exceeded all criteria for viscosity, surface tension, and specific gravity. In terms of fire-extinguishing capacity, all five products were superior to water, and some exceeded the performance of water by a factor of more than three. Miracle Foam (Japan) hardened to a solid state during the test of physical properties and was thus deemed unsuitable as a fire fighting product; due to the observed hardening, its specific gravity could not be measured. All five products were superior to water in terms of fire-fighting ability, and some exceeded the performance of water by a factor of more than three. Therefore, wildfire foam needs a regulation for test methods and tolerance limits of their properties and fire suppression ability in the near future.
A Change of Body Temperature and Inflammatory Markers Wearing Fire Fighting Equipment
Yoo, Donghoon ; Huh, Yusub ; Kim, Kihoon ; Shin, Jaesuk ; Bang, Changhoon ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 231~235
DOI : 10.9798/KOSHAM.2015.15.6.231
This aim of this study is to examine the change of body temperature(tympanic and mean skin temperature) and inflammatory marks (CRP, TNF-
) wearing fire fighting equipment in high temperature and to provide the basic date for the safety of fire fighters. The results of the study are as follows; Tympanic and mean skin temperature showed significant difference in main effect of time. Also, CRP and TNF-
showed significant difference in main effect of time. On the base of the results of the current study, wearing fire fighting equipment in high temperature environment was shown to affect body temperature and inflammatory markers. Further research on physiological variables during various fire-fighting tasks should also be carried out.
A Fundamental Study on Wi-Fi Based Communication Methods for Enclosed Spaces
Kim, Young-Duk ; Kwon, Soon ; Kim, HyungJun ; Park, Ji Won ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 237~242
DOI : 10.9798/KOSHAM.2015.15.6.237
Recently, thanks to advances in ICT(Information and Communication Technology), a large number of robot systems and specialized equipments are deployed in order to substitute for fire fighters in fire and disaster sites. However, when these unmaned devices are controlled by wireless remote controllers at the remote site, they may suffer from significant performance degradations such as interference, signal collision and fading due to unexpected indoor obstacles. In this paper, the extended measurements and analyses of wireless communication failures are conducted by using commercial wireless devices. All experiments are performed in confined and enclosed spaces such as office and dormitory which is consisted of a number of densely populated small rooms. Finally, the appropriate solutions for such enclosed spaces are proposed especially when wireless devices are deployed. We expect that the proposed communication scenarios can improve the search and rescue performance in real disaster sites.
Study on Prevention of Smoke Spread by Air Curtain System Containing Supply Nozzle and Exhaust Hood
Kim, Jung Yup ; Lee, Su Gak ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 243~250
DOI : 10.9798/KOSHAM.2015.15.6.243
More than 70% of the fatalities by fire is attributable to smoke and thus the importance of smoke control system is increasingly emphasized in a bid to deal with the smoke that has threatened the life safety. In advanced countries, many studies on forming the air curtain using a fast jet flow to block the smoke from spreading have been underway. In this study, air curtain system containing supply nozzle and exhaust hood is proposed as smoke blocking system and a full-scale test device was fabricated to measure the jet flow as well as 3D numerical analysis under the same condition was implemented. Furthermore, smoke blocking effect of air curtain system was numerically analyzed, focusing on ejection velocity of supply nozzle and smoke flow velocity. Consequently, when ejection velocity of supply nozzle was 20 m/s and smoke flow velocity was 1 m/s, 12.9 % of smoke flow passed through air curtain while 76.3% was blocked by air curtain.
Analysis of an Automotive Fire Case That Broke Out due to Knocking After ECU Mapping
Lee, Euipyeong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 251~259
DOI : 10.9798/KOSHAM.2015.15.6.251
In this study, the cause of a foreign car fire in tunnel was investigated and analyzed. The foreign car traveled 26,526 km about 20 months after vehicle registration. The starting part of the fire was the right and left end of mufflers, a connection between a right exhaust pipe and a right muffler, and around the spark plug where left engine oil leaked and burned. Because the fire started at more than two parts, it raised a doubt of arson. Fortunately, the result of engine investigation showed no relation with arson. A right piston head No. 4, an intake valve, and an exhaust valve were damaged and a right piston No. 4 was stuck. Therefore, the analysis suggested that the fire was caused by knocking.
Standardization and Future Challenges for the Replication Evaluation of Special Equipment for Fire Disaster
Park, Ji-Won ; Lee, Jung-Hun ; Jeon, KyuNam ; Kim, Hyungjun ; Kim, Hyun-Joong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 261~269
DOI : 10.9798/KOSHAM.2015.15.6.261
Recently, variety of special equipment for the fire disaster have been proposed for more aggressive lifesaving and effective response to various fire environment. The need for standardization has emerged to more effectively take advantage of these special devices in the field. Standardization plays an essential role in the industrial development and stage of technology application. It is necessary to precisely define the target of standardization for efficient standardized. Standardization of a fire disaster, it is possible to divide the system of fire environment, special equipment and evaluate the specialized equipment. There is a need for comprehensive environmental analysis because each region enclose the contents of standardization of new construction. And grading of the technology that is based on the standards must proceed. Maximizing the availability of special equipment through the standardization and grading. At the same time, basis for technological development are provided by the process.
A Study of Construction of in the Field Performance Evaluation for Specialized Equipment and Robots That are Utilized Such as a Fire Suppression/Navigation/Rescue
Kim, HyungJun ; Kim, YoungDuk ; Jeon, KyuNam ; Kim, HyunJoong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 271~276
DOI : 10.9798/KOSHAM.2015.15.6.271
Because fire-fighting special equipments and fire-fighting disaster robots made at home and abroad have been developed with a focus on service model of products and merchandising, the lack of validation at standardized performance evaluation environment is pointed out as a disadvantage. In addition, a number of special equipments and robotic system are developed to be used in various disaster site such as the fire, earthquake, building collapse around the United States, Japan, Europe and other developed countries, however, the establishment of systematic environment testing and evaluation site is incomplete. In this study, to build the environment for on-site performance evaluation on the simulation of the fire situation in confined space, we analysed the existing cases and status for the establishment and presented the various technical methods for building the on-site testing and evaluation.
A Study on the Toxicity of Combustion Gases for Inner Floor Materials
Park, Youngju ; Lee, Haepyeong ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 277~283
DOI : 10.9798/KOSHAM.2015.15.6.277
In this study, we considered the toxicity of the combustion gases for the indoor floor materials such as carpet tiles, rubber tiles, decorated tiles, monorium, and PVC vinyl asbestos using the cone calorimeter and the NDIR analysis equipments. Only 5 types of gases (CO,
, NO and
) were selected to analyze among the combustion gases because of the limitations of NDIR equipment. For monorium the concentrations of
, CO and
were relatively higher and the maximum concentration of
was 13 times higher than rubber tiles. Especially, the maximum concentration of CO was 3.09 times higher than PVC vinyl asbestos and it was 3.0~9.2 times higher than the permissible concentration of 50 ppm. For carpet tiles the concentration of NO was relatively higher and it was 2.9 times higher than rubber tiles. Also, the maximum concentration of
was 2.25 times higher than PVC vinyl asbestos but it was lower than the hazardous concentration of 117~154 ppm. Therefore, the danger of
and CO was considered to be much higher in fires with monorium.
A Study on Empirical Model for Combustible Supplies in Intelligent Buildings
Chae, Seung-Un ; Kwon, Oh Sang ; Kim, Heung Youl ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 285~291
DOI : 10.9798/KOSHAM.2015.15.6.285
In this study, real fire tests have been performed for the fire behavior and temperature analysis of the compartment. The size of Mock-up experiments were 3 m length, 3.2 m wide, 2.5 m height m. The BFD curve method of C.R. Barnett is adopted to study a empirical model for fire compartment temperatures. The fire load was
with office combustible supplies including access floors. The temperatures in the Mock-up compartment were measured using two different locations of thermocouple trees. These conclusions and experiment data obtained in this paper could be helpful in reference for the fire simulation, fire hazard assessment and fire protection design (including PBD). Based on experimental data, BFD curve and mathematical models need to be discussed to predict temperature curve in flashover and fire spread in the compartment. Also, this empirical model study needs more test to verify and optimize.
Dynamic Analysis of Railway Structures using Multibody Contacts
Rhee, Inkyu ; Roh, Young-Sook ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 293~299
DOI : 10.9798/KOSHAM.2015.15.6.293
Contact responses due to 3D wheel-rail interaction and rail deflection were investigated. The comparison of rail deflection and contact pressure were discussed regarding on contact area/shape and different loading method. Three different simulation models were examined; (1) strong format of dynamic equilibrium equations using Eulerian beam and Timoshenko beam theories, (2) moving load simulation with 3D rail-sleeper-soil model by assuming the contact area upon train axle load and similarly, and (3) moving mass simulation model by surface-to-surface contact of rigid wheel and elastic rail under angular velocity control for forward rolling. The contact geometry shaped with 20~27 mm width and 93 mm long with ellipsoidal area and its value ranged from
. This shows the similar behavior pattern of Song et al. (2014) and reaches maximum 490 MPa of unsymmetric contact pressure.
Life Cycle Energy Analysis of Pipe Rehabilitation and Replacement Strategies in Water Pipeline Systems
Yoo, Do Guen ; Lee, Seung Yub ; Lee, Ho Min ; Jun, Hwandon ; Kim, Joong Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 301~310
DOI : 10.9798/KOSHAM.2015.15.6.301
The life cycle energy analysis of social infrastructures including water pipeline system considering installation, maintenance control, operation, and dismantling is essential component. In this study, life cycle energy analysis was applied to establishment of pipe rehabilitation/replacement strategies and energy consumption and hydraulic factors (nodal pressure) were used for result comparisons. The life cycle of water pipeline system was classified into three steps; 1) manufacturing and installation, 2) rehabilitation, maintenance, replacement and energy recovery form replacement, and 3) disposal. The energy consumption of water pipeline system was calculated at each step. In case of rehabilitation/replacement strategies two criterions were applied; 1) the time after the pipe was laid and 2) variance of pipe roughness coefficient. The developed method in this study was applied to a real water pipeline system of K-block in J-city, Korea and the results were analyzed. The developed method in this study can be applied to suggestion of basic method for specialization of water pipeline system maintenance technique considering energy consumption.
Application of Truss Type Safety Barrier for Increasing Span Length of Temporary Bridges
Oh, Minsik ; Lee, Kiho ; Im, Seokbeen ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 311~320
DOI : 10.9798/KOSHAM.2015.15.6.311
Recently, environmental issues have been raised in offshore bridge constructions, which requires constructing temporary bridges in shallow water levels instead of temporary embankment roads. Therefore, this has significantly increased the amount of trestle required in offshore bridge projects. Due to limitations in using marine equipments to approach shallow waters, the phased forward method needs to be implemented in constructing a trestle in shallow waters. However, depending on the capacity of the crane, the phased forward method restricts the span length of the trestle, which would critically increase the construction period. Therefore, in order to perform offshore bridge projects, more competitive approaches are required to reduce the construction period and the quantity of trestle through optimized designs. This research adopts high strength steel and truss type safety barrier as members to control deflection and propose ways of elongating the span of the trestle. Under the same conditions, the application of SM490 steel and truss type safety barrier enable the trestle span to increase up to 21 m. In addition to considering a trestle at a total length of 1050 m, the proposed approach can reduce the number of spans by 33% and decreasing the quantities of sub-structures and the construction period by approximately 2 months.
Stability Analysis of Unsaturated Soil Slope Considering Rainfall Infiltration by Two-Pahse Flow Model
Cho, Sung-Eun ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 321~329
DOI : 10.9798/KOSHAM.2015.15.6.321
Most previous studies on the rainfall infiltration and its influence on slope stability were based on the single-phase water flow model. The purpose of this study is to study the effect of interaction of air and water flow on the slope stability. In this study, two-phase flow analyses were conducted for weathered residual soil slopes with thin soil overlying impermeable bedrock. Results of the flow analysis were used as input for stability analysis by strength reduction method. Strength reduction method considers mechanical equilibrium to evaluate the effect of rainfall infiltration on the slope stability. The results show that remarkable delaying effects by air flow on the propagation of the wetting front and the deterioration of slope when surface ponding occurs during infiltration. On the other hand, the influence of the pore air flow on the slope stability can be neglected in the non-ponding situation with small rainfall intensity.
Compressibility and Thermal Characteristics of Plant Biomass Ashes
Jeong, Hyangseon ; Mohammad, Jafari ; Ahn, Jaehun ; Shin, Hyunsuk ; Jung, Jongwon ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 331~336
DOI : 10.9798/KOSHAM.2015.15.6.331
Biomass has become one of major sources of renewable energy, but, after combution, the ashes of biomass are not well recycled. The compressibility and thermal characteristics of biomass ashes were experimentally analyzed and compared to silica sand, in attempt to utilize the biomass ashes as sustainable construction material. The mean particle sizes of wood and sugarcane bagasse ashes were 0.15 mm and 0.04 mm, respectively; the particles were angular and had non-uniform array. The compressibility of biomass ashes were much larger than those of sands with the same initial loading; the thermal conductivity lower. In addition, the more saturated, the higher thermal conductivity. The compressibility and thermal characteristics of biomass ashes, reported in this paper, are for uniform materials that contain relative high void contents; the mixture of soil and biomass ashes, which has denser composition, needs to be inspected further.
Back-Calculation of Soil-Water Characteristics Curve for Permeable Pavement Material Based on Infiltration Tests
Kim, Hyoungwon ; Ahn, Jaehun ; Shin, Hyunsuk ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 337~343
DOI : 10.9798/KOSHAM.2015.15.6.337
Permeable pavement systems, an Low Impact Development technique, are widely used for pedestrian and bicycle roads, and parking lots, to relieve the flooding and enhance water cycle, which arises due to climate change and urbanization. However, due to lack of analytical means, permeable pavements are constructed most of time without knowing their performance in reducing runoff. In this paper, saturated permeability and porosity of a pervious concrete sample were experimentally estimated, and a set of infiltration model test was conducted; then, finally, the soil-water characteristics curve of the sample was back-calculated. In inverse analysis, van Genuchten model was selected, and Levenberg-Marquardt method was used for parameter searching algorithm. The results of soil-water characteristics curve presents the air-entry suction pressure is little below 1 kPa, and all the water expels at a suction pressure of 10 kPa. When compared to typical sands, the volumetric water content of pervious concrete drops more steeply with increasing suction pressure.
A Case Study of Colluvium Slope Failure On Tunnel Entrance
Lee, Kyu-Dal ; Jung, U-Yong ; Che, Su-man ; Lee, Jin-Duk ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 345~351
DOI : 10.9798/KOSHAM.2015.15.6.345
The tunnels of highway are often constructed on mountain valley which exist a weak colluvium. In this study, we investigated the cause of slope failure on the tunnel entrance. Geotechnical investigation and electrical resistivity survey was conducted to determine the cause for the slope failure. From the result of geotechnical investigation, The depth of colluvium is larger than the original design. Also, abilities of anchor did not take effect because to position on the loose colluvium. From the result of electrical resistivity survey, the low electrical resistivity zone occurred on the interface between colluvium and bedrock which occurred slope failure.
A Prediction of Entrainment Growth Rate for Debris-flow Hazard Analysis Using Multiple Regression Analysis
Yoon, Seok ; Lee, Seung-Rae ; Park, Jun-Young ; Seong, Joo-Hyun ; Lee, Deuk-Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 353~360
DOI : 10.9798/KOSHAM.2015.15.6.353
Recently, landslide and debris-flow disasters caused by severe rain storms have frequently occurred. Landslides can be mobilized into debris-flows, and then they transport downwards with huge volumes of sediments in an extreme rainfall condition. It is necessary to analyze flow direction and route of debris-flow for the prevention of debris-flow disaster. Many numerical models have been developed to consider these properties of debris-flow, and DAN3D which is a continuum dynamic runout model is known to simulate real events of debris-flow in Korea. DAN3D considers volume increase of various sediments induced by an entrainment mechanism. However, it uses several user-prescribed parameters, and there is no clear method to determine the parameter values. Therefore, this research analyzed 35 previous debris-flow events in Korea and collected values of dependent and independent variables to decide the growth rate. Besides, a multiple regression analysis was conducted and an empirical solution with an
value of 0.824 was suggested for the prediction of growth rate. In the solution, all statistical assumptions for the multiple regression analysis were satisfied.
The Analysis Method of Future Flooding Discharge considering Climate and Land-use Change using Dyna-CLUE
Han, woo suk ; Jeung, Se Jin ; Kim, Byung Sik ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 361~371
DOI : 10.9798/KOSHAM.2015.15.6.361
In this research, the analysis method of future flooding discharge considering climate change and land-use change is proposed. In order to reduce uncertainty of climate change data, RCP 8.5 climate change scenario data is compared with long-term observed rainfall data in case study area and calibrated by regional parameters which can reflect regional weather characteristics and is required parameters for daily weather generation for future climate change data. Using calibrated RCP 8.5 data, the probability rainfall of 1 day and 5 days rainfall duration is calculated by 3 different time zone(Future 1 : 2011~2040, Future 2 : 2041~2070, Future 3 : 2071~2100). The algorithm of sub-module in Dyna-CLUE model is used to calculate the future land-use change by 3 different land-use scenarios and 3 different time zone. The S-RAT which is distributed hydrology model is used to simulate the future discharge by different time zone, 1 and 5 days rainfall duration and land-use change scenarios. As a result, the peak discharge is increased as far future and more urbanized. However, climate change is more effect to increase of peak discharge than the land-use change. Although to simulate future data such as climate and land-use change has a lot of uncertainty, those kinds of research must be required to reduce future natural disaster damage. It is expected that the analysis method in this research would be contribute to more correctly quantify the future flooding risk.
Parameter Estimation and Uncertainty Assessment of a Soil Erosion Model Using Data Assimilation Method
Kim, Yeonsu ; Lee, Giha ; Lee, Daeeop ; Noh, Seong Jin ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 373~382
DOI : 10.9798/KOSHAM.2015.15.6.373
This study aims to develop the CSEM-PF by combining Particle Filter (PF) and Catchment-scale Soil Erosion Model (CSEM) for time-variant parameter estimation and uncertainty assessment. The CSEM-PF can provide information regarding uncertainty of simulation output as well as model parameters of nonlinear soil erosion models. The CSEM-PF was applied to the upper Guemho river basin with two rainfall events. Then we estimated the feasible model parameters of CSEM at each time step and generated uncertainty bounds of both hydrograph and sedigraph. The simulation results show that rainfall-runoff parameters are well estimated as well as good agreement with observed hydrograph with relatively small uncertainty bounds. On the other hand, erosion-sediment yield simulation results led to larger uncertainty bounds than hydrograph results. In particular, parameter estimation with a few sediment observations provided less uncertain (more reliable) sediment discharge than the case with inter- or extrapolated discharge-sediment relation equation.
Evaluation of Rainfall Intermittency on the Simple Kriging
Ro, Yonghun ; Yoo, Chulsang ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 383~393
DOI : 10.9798/KOSHAM.2015.15.6.383
This study evaluated the effect of rainfall intermittency on the quantitative estimation of rainfall field by the simple Kriging method. For this purpose, this study analyzed and compared the three different data fields generated with different ratios of zero values. The variogram for each data field was also derived to evaluate the effect of the ratio of zero values on the shape of variogram. All three variograms have also been applied to each data field, whose simple Kriging application result was then analyzed and compared. Finally, above procedure was repeated with the real radar data from the Bislsan Radar. Summarizing the results are as follows. First, for the data field with larger ratio of zero values, the correlation lengh of variogram increases but the threshold value decreases. Second, the use of the corresponding variogram to the data produces the most similar pattern of interpolated data field by simple Kriging to the original data. Finally, the same result could also be confirmed from the application to the real radar data field.
Alternating Inappropriate Employment of the Thiessen Method in Estimating Design Flood for Small and Ungaged Basins
Lee, Hyunseung ; Lee, Taesam ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 395~403
DOI : 10.9798/KOSHAM.2015.15.6.395
Thiessen method has widely been used to estimate areal rainfall on a basin. However, Thiessen method contains some problems by improper use in practice. Therefore, in this study, we analyzed the estimated design flood from Thiessen method on a small or ungaged basin and how the selection or the usage of Thiessen method affects estimating the design flood. Furthermore, we widely searched existing cases whose design flood were estimated with Thiessen method. Among those cases, we selected the cases that might be problematic on the watershed division using the Thiessen method. In order to assess the effect of Thiessen method in estimating design flood, we employed the standard process suggested by the national flood design manual as follows: (1) selecting a weather station that has long record length and is close to an interested watershed; (2) recalculating the design flood with the standard process. The results indicate that the estimated design flood from the standard process is different from the flood with the Thiessen method. This difference results from the selection of the inappropriate use of multiple weather stations following to the theory of the Thiessen method. Finally, the current study advocates the standard design flood estimation process using a single station is better than the inappropriate use of Thiessen method. In addition, when selecting a single weather station, we prioritize the station with long record length and high credibility, which is generally run by Korea Meteorological Administration (KMA).
A Study of Algae Control in ARA Waterway by Improvement of Canal Operation
Park, Chulgue ; Chong, Suna ; Park, Yongsoon ; Park, Woncheol ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 405~414
DOI : 10.9798/KOSHAM.2015.15.6.405
ARA Waterway is artificial canal of brackish water connecting the West Sea and the Han river in South Korea. In this investigation, we reminded how to improve and apply the stream flow method gradationally (from the test operation period to 2014), and considered how the method contributed to the reduction phytoplankton by discharging the surface water and increasing the stream flow rate in ARA Waterway. We also confirmed the possibility which could be major solution about reducing algae in major canal by applying the stream flow method, as discharging the surface water including high concentrated algae and increasing inflow of the West sea water. Thus, we concluded that discharging surface water and increasing stream flow rate are desirable method to prevent the algal bloom in the canal when we can control the stream flow via handling the lock gate and culvert gate.
Three-dimensional Laboratory Experiments for Tsunami Force Coefficient at Imwon Port
Kim, Byung Ho ; Yoon, Jae-Seon ; Han, Se Jong ; Cho, Yong-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 415~422
DOI : 10.9798/KOSHAM.2015.15.6.415
Tsunamis mainly triggered by impulsive undersea earthquakes are one of most devastating natural disasters. They can travel long distances in all directions from the source region and strike not only neighboring countries but also distant countries. For example, the Central East Sea Tsunami occurred near the Japanese Western Coast on May 26, 1983 stroke the Eastern Coast of Korea across the East Sea. The tsunami killed 3 people and caused property damage at Imwon Port. Thus, an efficient and proper countermeasure is essential to mitigate damage. In this study, a series of laboratory experiments are carried out to investigate the tsunami force acting on coastal structures. A so-called tsunami force coefficient is found at Imwon Port. The coefficient covers most of forces acting on structures due to tsunamis.
Future Drought Projection in Korea under AR5 RCP Climate Change Scenarios
Park, Myungwoo ; Lee, Okjeong ; Park, Yoonkyung ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 423~433
DOI : 10.9798/KOSHAM.2015.15.6.423
In this study, spatio-temporal behavior of future drought in South Korea under AR5 RCP climate change scenarios is projected. In order to investigate more explicitly the effect of climate change, future drought conditions for the region where artificial water supply systems are not well equipped are analyzed. Using South Korea-detailed 1-km resolution daily precipitation data provided by Korea Meteorological Administration as future climate information, annual mean numbers, mean drought event duration, and mean drought event severity of present and future drought events are compared, respectively. As a result, while the annual mean numbers of future drought events are not expected to be increased in most regions, the mean drought event duration and severity are predicted to be increased in the central region.
A Study on the Calculation of Non-point Source Load by Long-term Monitoring and Modeling in Nakdong River Watershed
Kal, Byung Seok ; Kwon, Heongak ; Im, Toehyo ; Park, Jae Beom ; Kim, Changhee ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 435~442
DOI : 10.9798/KOSHAM.2015.15.6.435
In order to identify the characteristics of the Nakdong River runoff from non-point sources in 2007 were carried out using the monitoring unit for monitoring data were pointing to build a runoff model. EMC and estimating runoff loadings for the pollution that is discharged from the unit by using a pointing model and monitoring data were presented as a basis for improvement of the current intensity as compared with the conventional intensity. In the case of BOD and COD, if high tendency in the industrial area and traffic areas in urban areas appeared SS, TN, of TP, it was higher in agricultural areas. This is the case of a contamination source which flows during rainfall is determined that the outflow characteristic changes according to the land use.
The Improvement on the Empirical Formula of Reduced Target Loading Ratio for Bio-Retention Non-point Source Control Facilities
Yeon, Jong Sang ; Sim, Kyu Bum ; Lee, Okjeong ; Kim, Sangdan ; Kim, Eung Seok ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 443~450
DOI : 10.9798/KOSHAM.2015.15.6.443
In this study, the formula of reduced target loading ratio taken into account both the weir and orifice of a bio-retention pond which is one of non-point source control facilities is derived. SWMM is used to develop the formula according to different design capacities of the facility. A comparison of the improved and existing formula shows that the newly proposed formula gives higher value of reduced target loading ratio than the previous formula in the case that the pond has been installed in the same capacity. Since most of ponds have a discharge process through an orifice, the proposed formula is thought to be more reasonable, it can be seen that the existing formula for the reduced target loading ratio has underestimated the amount of intercepting non-point pollutant sources.
Analysis of 2015 Drought in Korea Using Real-Time Drought
Park, Myungwoo ; Jang, Suhyung ; Kim, Sangdan ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 451~458
DOI : 10.9798/KOSHAM.2015.15.6.451
In this study, the spatial and temporal evolution of the drought event in Korea peninsula which occurred in 2015 was analysed using Real-Time Drought Index(RDI). RDI can be applied to determine actual drought conditions at an area where artificial water supply systems was not equipped. To calculate RDI, daily precipitation data from 60 observations and water demand of 164 basic local government regions were used. As a result, the 2015 drought event began in Gangwon-do province, and has spread to most parts of the central provinces in one month. Due to June 25-27th rainfall event, the drought was analyzed to disappear in most areas. However, in municipalities encountered a severe drought including Gangneung, it has confirmed that such amount of rainfall was insufficient to turn to back into normal state. In addition to this, according to hit rate 90.4% and false alarm rate 9.6%, RDI is an adequate drought index to monitor drought.
A Study on Water Quality Prediction Model over Midterm Considering Correlation between Water Quality and Hyrologic Factors
Kim, Mieun ; Kim, Jaemoon ; Ye, Sungjae ; Park, Jaebeom ; Yun, Miyeon ; Shin, Hyunsuk ;
Journal of Korean Society of Hazard Mitigation, volume 15, issue 6, 2015, Pages 459~470
DOI : 10.9798/KOSHAM.2015.15.6.459
Runoff and water quality factors generated from the watershed show strong nonlinear characteristics on their interrelationship. A study of prediction of water quality might be essential with correlation analysis among hydrologic and water quality factors affected by inflow in a watershed. The study selected Nakbon K located in downstream of Nakdong River. A prediction model of water quality based on back propagation algorithm considered nonlinear correlation between water quality observed under Ministry of Environment and hydrologic factors. The established models through qualitative analysis among the various factors showed good results between observed and simulated values. The model could be seen from previous models and improved the prediction accuracy comparing with the previous models.