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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 12, Issue 6 - Dec 2012
Volume 12, Issue 5 - Oct 2012
Volume 12, Issue 4 - Aug 2012
Volume 12, Issue 3 - Jun 2012
Volume 12, Issue 2 - Apr 2012
Volume 12, Issue 1 - Feb 2012
Selecting the target year
Experimental Study of Vertical Fire Spread of Exterior Wall Finishing Materials
Kweon, Oh Sang ; Yoo, Yong Ho ; Kim, Heung Youl ; Min, Se Hong ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 1~6
DOI : 10.9798/KOSHAM.2012.12.5.001
In this study, we have analyzed the full scale fire test from the fire accidents of finishing materials on the external wall of the buildings, and conducted the vertical fire experiment of finishing materials on the external wall of the buildings. As the ISO 13785-2 fire test, a international test standard, has been judged to be most appropriate as the test method that could figure out the fire performance of finishing materials on the external wall with the effect of external flame break-out due to the fire in the unit compartment among the real scale fire test methods, we have built up the experimental equipment for the full scale vertical fire experiment of finishing materials on the external wall of the buildings. As a result of the full scale vertical fire experiment, the fire has been spreaded up to 4m upwards within about 2 minutes at the point of 5 minutes when the external flame break-out was at maximum. The temperature was recorded as
, and the test result showed that general aluminum composite panel was vulnerable against spread of the vertical fire on the openings due to external flame break-out.
A Study for Estimation of Ventilation Capacity of Large Enclosure Considering Evacuation
Ahn, Chan Sol ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 7~12
DOI : 10.9798/KOSHAM.2012.12.5.007
In this study, we reviewed the performance of smoke control system by national fire safety code to secure evacuation time of occupants in case of a fire in large enclosure structures. Towards this end, we performed numerical analysis modeling of the existing large underground shopping mall and investigated types of business and combustibles loaded inside the stores situated at the shopping mall to fulfill the same configuration requirements with actual fire load conditions. To compare effects of smoke control system by national fire safety code, we created 11 smoke control scenarios of large enclosure shopping malls according to the ventilation capacity and conducted numerical analysis of evacuation behavior of occupants and the spread of fire against each scenario. In addition, to compare the results of the numerical analysis, we analyzed total heat release amount, flash-over occurrence time, residual amount of soot indoors and the number of evacuation failures and the dead, thereby deducing the optimal ventilation capacity.
A Study on the User Recognition of Safety for Waterfront Area of Seoul
Kim, Jin Wook ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 13~18
DOI : 10.9798/KOSHAM.2012.12.5.013
Hangang Waterfront is the place for rest and refresh area for the people since 1988. But safety concern is becoming increase as increasement of crime and natural disaster. In this research, the elements which could affect waterfront safety were analyzed and a survey was carried out to know basic purpose of waterfront visiting, assessment of waterfront area safety by user, the elements which could affect to safety of waterfront and the elements for natural disaster correspondence. Through this examination, 34% visitor assessed that waterfront is safe and 42 % answered water edge could be danger for the question which part of waterfront area could be dangerous. Also 42% of visitors answered the had intention to participate in education of disaster and they prefer media like broadcasting and internet website for the method of disaster education. As a conclusion Hangang waterfront safety recognition status was examined and we could find out the subjects and directions for improvement.
Effective Tangential Modulus of Steel Axial Members with Hot-rolled I-shaped Section Considering Parabolic Residual Stress Distribution
Choi, Jin Hee ; Kim, Seungjun ; Lee, Kyung Suk ; Kang, Young Jong ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 19~28
DOI : 10.9798/KOSHAM.2012.12.5.019
In this study, effective tangential modulus of the steel axial member with hot-rolled I-shaped section was investigated and suggested considering parabolic residual stress distribution. When finite element analysis is performed using beam element, some methods such as plastic zone method, elastic-plastic hinge method and refined plastic hinge method can be used for considering material nonlinearity of steel members. In conventional elastic-plastic hinge method and refined plastic hinge method, the CRC tangential modulus of steel members which have residual stress was used in order to consider gradual yielding effect induced by axial forces. But, the CRC tangential modulus was derived based on Euler's inelastic buckling equation. So, it is not rational when the CRC tangential modulus is adopted for considering gradual yielding effect of axial member because the equation is relative with bending behavior. It is needed that the rational tangential modulus equation for axial members which have residual stress. The new effective tangential modulus was derived for considering gradual yielding effect of axial members which have parabolic residual stress pattern. As well as the shape of the stress pattern, maximum and minimum stress value can be considered. By nonlinear analysis using ABAQUS V6.10, suggested equation of the tangential equation was validated.
Study of the Structural Displacement Estimation by the Acceleration Measurement with an Effective Noise Filtering Method
Kim, Seungjun ; Im, Seok Been ; Choi, Jun Ho ; Kang, Young Jong ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 29~40
DOI : 10.9798/KOSHAM.2012.12.5.029
In this study, the estimation method for the structural displacements by the acceleration measurement is investigated for effective real-time structural monitoring. Theoretically, the velocity and displacement data during the specific period can be obtained by integration of the measured acceleration. But, the integrated data is highly affected by unexpected error sources such as noise signal. So, the effective and rational method for the noise elimination or minimization should be suggested and used. In this study, an effective noise filtering method for an useful displacement estimation by double integration is suggested based on the characteristics of structural dynamics. For the rational noise filtering technique applied to the measured acceleration data, the multi bandpass filter, which allows the signals nearby the peak frequencies of measured data, is newly suggested. By the suggested filtering and double integration method, the estimation method of structural displacements using an acceleration measurement is suggested in this study. The accuracy and rationality of the suggested method was validated using the numerical example obtained by finite element analysis. In the validation, the displacement data estimated by the suggested method was directly compared with those obtained by highpass filter and bandpass filter, formerly well known methods.
A Parametric Study on Shear Buckling Stresses of Steel Pile
Mha, Ho Seong ; Cho, Kwang Il ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 41~46
DOI : 10.9798/KOSHAM.2012.12.5.041
Parametric analysis has been throughly conducted to see the shear buckling stresses of steel piles made of STK400, STK490 and SM570 by using detailed FEM model via commercial code ABAQUS. The thickness of pipe is 2 mm, 40 mm and 75 mm, and radii and lengths are determined based on the values satisfying the following relationship as R/t=20~400, L/R=1~3. Nonlinear buckling behaviors are simulated by giving the initial imperfection with the value of 1/1000 in the longitudinal direction according to the first buckling mode obtained from the elastic buckling analysis.
is prepared to calculate the shear buckling stresses based on the beam theory, and
decreases as L/R increases. The shear buckling stresses is found to decreases as R/t and L/R increases for all steel types considered. The rate of decrease is rather high for the high strength steels. It should be noticed that the decrease rate is sensitive to the length of pile.
Application of the Rate of Change of Acceleration to Damage Evaluation
Choi, Sanghyun ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 47~51
DOI : 10.9798/KOSHAM.2012.12.5.047
Most damage evaluation methods for a structure developed to date utilizes modal responses extracted from acceleration measurements, which involve inevitable errors during the extraction process. Also, displacements, obtained by integrating acceleration measurements, may contain serious deviation due to such errors as in initial conditions. However so far no attempt has been made to identify the feasibility of applying jerks and snaps in damage evaluation. In this study, the applicability of jerks and snaps to damage evaluation for a structure is conducted. The mean strain energy theory in time domain based on displacement measurements is utilized for the purpose of the study, and the feasibility of isolating local damage is verified via a numerical example of a simple beam. From the study, it is found that, unlike snaps, jerks can be utilized directly in evaluating damage in a structure.
Sensitivity of Resistivity Measurement of Steel-Fiber Reinforced Concrete
Moon, Do Young ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 53~61
DOI : 10.9798/KOSHAM.2012.12.5.053
For condition surveying of concrete structures, corrosion rate or permeability is to be one of important checklists and is usually evaluated by resistivity measurement on concrete surface. But, it is known that the conductive materials, such as embedded steel rebars, affect the observed resistivity. This could be more severe in the case of steel-fiber reinforced concrete structures. In this study, the experimental program were conducted on steel-fiber reinforced concrete specimens with 1%, 2% and 3 Vol% of hooked steel fibers to provide more information about the effect of distributed steel fibers on electrical resistivity measurements on concrete structures. The effect of moisture content, embedded steel reinforcement and its corrosion state were investigated also. The results show that the amounts of mixed fibers and moisture content significantly affect more than others. Consequently, their effect should be carefully considered for the evaluation of corrosion rate or permeability of steel-fiber reinforced concrete structures.
Real-time Structural Dynamic Test Using Parallelized Control Algorithms and Optimized Hybrid System
Na, Okpin ; Kim, Sehoon ; Kim, Sungil ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 63~73
DOI : 10.9798/KOSHAM.2012.12.5.063
Real-time hybrid dynamic test is an economical and efficient method capable of the replacement of the shaking table test. The purpose of this paper is to optimize the control algorithms and the system configuration for the prediction of the structural dynamic behavior with the interaction between a physical substructure and a numerical modeling in the hybrid testing system. FEAPH, nonlinear finite element analysis program for hybrid, was developed with a fixed number of substep iteration method and parallel computational technique in the control algorithms. These algorithms can improve the inefficiency of iterative methods caused by sequential process, so that the computational time can be reduced. Furthermore, the previously used data communication method and the interface between a substructure and an analysis program were simplified in the control system. In order to verify the accuracy of the hybrid system, the dynamic test with steel framed structure was conducted. As the results, the processing time in hybrid test with FEAPH was improved up to 10% rather than with OpenSees. Moreover the testing performance is almost the same trend within a 5% error level.
Development of Flood Risk Assessment Model
Joo, Jin Gul ; Lee, Jung Ho ; Park, Moo Jong ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 75~81
DOI : 10.9798/KOSHAM.2012.12.5.075
The frequency and intensity of disaster is increasing by climate change and the establishment of disaster management policy and its application in practice is necessary. for that, it is important to define the risk and assess estimate the degree of the risk in a region. In this study, to assess the risk by damage by storm and flood in a region, three disaster indices(occurrence, vulnerability and damage analysis index) were developed. And a method for estimate risk environment was suggested using the indices. The developed method were applied at 230 regions to assess locality risk. The results of this study are expected to utilize to disaster management policy.
Estimation of Monthly Areal Precipitation using Daymet and PRISM
Kim, Jong Pil ; Kim, Gwangseob ; Lee, Woo-Seop ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 83~90
DOI : 10.9798/KOSHAM.2012.12.5.083
A mixed model interpolating monthly precipitation linking between Daymet and PRISM(Parameter-elevation Regression on Independent Slope Model) was proposed. And it was applied from January 2006 to December 2010(during 60 months) using 348-AWS(Automatic Weather Station) and 60-ASOS(Automated Synoptic Observing System) in Korea. The estimated monthly precipitation amount was compared with observed records at total 408 weather stations using the Jackknife validation method. The results indicated that the model reflected sufficiently well the spatial distribution pattern of the monthly precipitation. However, it was underestimated when the maximum precipitation at a target station occurred in the influence circle. This is the systematic error of the model based on a statistical technique and will get solved through the calibration of model parameters.
A Study on the Parameter Stabilization of Palmer Drought Severity Index
Moon, Jang Won ; Lee, Dong Ryul ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 91~99
DOI : 10.9798/KOSHAM.2012.12.5.091
Drought is a hydrologic phenomenon due to the abnormal water deficiency and a natural disaster lasting for a long time through a large area. Continuous drought monitoring is very important in minimizing damage caused by severe drought. Generally, drought index is used for drought monitoring and PDSI is one of popular indices in the world. In this study, the effect of data duration is analyzed on 3 parameters (water-balance coefficient, climatic characteristic factor, and duration factor) in PDSI. The analysis shows that the effect of data duration on the climatic characteristic factor among 3 parameters is relatively clear and similar patterns are found in the other parameters at some weather stations. Therefore, PDSI parameters need to be recalculated using the observation data in Korea for the correct application of PDSI. In addition, the parameter stabilization of PDSI requires observation data with period longer than 40 years.
Flexural Strength Characteristics of PVA Fiber Reinforced Clayey Soil-Cement Mixture
Kim, Woo Sik ; Jung, Du Hwoe ; Cho, Il Muk ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 101~111
DOI : 10.9798/KOSHAM.2012.12.5.101
Currently, the stability analysis of embankments founded on soft ground stabilized with DCM (Deep Cement Mixing) columns has been performed based on a limit equilibrium analysis by using a shear strength of composite ground. Recent research efforts based on centrifuge tests, numerical analyses, and case studies revealed that the group of DCM columns might fail by several failure modes governed not only by shear failure but also by bending failure. So, the applicability of current practice for the stability analysis of embankments founded on soft ground stabilized with DCM columns is uncertain. Therefore, the bending moment capacity of DCM columns needs to be incorporated in the stability analysis. In this study, PVA fiber has been added to improve the bending moment capacity of DCM columns. This paper presents the effects of cement contents, PVA fiber contents and lengths, and curing periods on the flexural strength characteristics of PVA fiber reinforced soil-cement mixtures through a series of third point bending tests.
Vegetation and Strength Characteristics of Planting Blocks Prepared Cemented Sand and Gravel Reinforced by Geosynthetics
Yoon, Yong Sun ; Kim, Yong Seong ; Yeon, Kyu Seok ; Kim, Ki Sung ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 113~120
DOI : 10.9798/KOSHAM.2012.12.5.113
This study was performed to evaluate the strength characteristics, the planting properties and root potential of planting block with seeding three species of grasses in CSG blocks manufactured by cemented sand and materials (CSG) in order to develop CSG planting blocks reinforced by geosynthetics. Four types of CSG mix designs with cement contents were determined, and the mechanical properties of CSG materials with polyvinyl alcohol were studied experimentally. To analyze growth properties of plants within CSG block, visual cover, plant height, root potential and the flexural strength were measured at 28 days after seeding. The visual cover of kinds of plants evaluated by visual rating system were in the range of 7.5~9.5 in case of seeding three species of grasses in 4 weeks after seeding. The flexural strength of planting blocks prepared with CSG and Polyvinyl alcohol (PVA) were in the range of 1.02~3.76 MPa in 28 days. It is expected that this study will contribute to increasing application of CSG materials as well as to increasing the utilizing of PVA materials as a environmentally friendly CSG method.
Evaluation of Deformation Characteristics of Residual Soils under K
Condition at Full Strain Ranges
Oh, Beyung-Sam ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 121~126
DOI : 10.9798/KOSHAM.2012.12.5.121
The small-to-large strain traixal testing apparatus has been adopted to evaluate the deformation characteristics of soils at full strain ranges (
). In this study, a lateral deformation measurement system was additionally installed to the apparatus in order to measure Poisson's ratio. It was verified using polyurethane specimens and then used to set up
-consolidated state of soil specimens by monitoring the lateral deformation variation and adjusting axial stresses during a consolidation step. Test results show that Poisson's ratio, elastic modulus, and nonlinear stress-strain relations under
condition are significantly different from those under isotropic condition.
The Effect of Pavement Roughness on Fuel Efficiency for Passenger Cars in Korea
Kim, Je Won ; Lee, Soo Hyung ; Yoo, In Kyoon ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 127~133
DOI : 10.9798/KOSHAM.2012.12.5.127
The analysis of fuel consumption due to pavement roughness becomes more important in the economic aspect as well as the environmental aspect related to greenhouse gas emissions. Because vehicle operating costs and carbon dioxide emissions are increased by fuel consumption growth if pavement roughness increases. Therefore, it needs to analyze the change of fuel consumption for vehicles due to roughness in order to maintain pavement and greenhouse gas emissions efficiently. In this study, the amount of fuel consumption due to degree of roughness is measured by using two quantitative values such as voltage signal from fuel injector of vehicle and the speed from GPS. As the results, it was found that the fuel consumption increases with the rate of 100 mL/100 km as IRI increases with rate of 1 m/km.
Feasibility Study on the Designation of a Special Disaster Area by Considering the Climate Extreme Value
Jung, Wooyoung ; Hwang, Donghwan ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 135~141
DOI : 10.9798/KOSHAM.2012.12.5.135
Due to natural disasters, the central government generally extends support for the local authorities faced with disaster recovery and the loss of public and private damages. Also, the current methodology for designation of an area as a special disaster zone has limitations in the distinguishing a regions from one another according to disaster intensity factors and physical damages in the zones. This study addresses the damage estimation in a region by using the annual extreme values of daily precipitation while incorporating current techniques for the damage estimation. Consequently, this research indicated that regardless of the extreme value for the precipitation record per hour, some regions were declared as the national disaster zone, but the other areas were not designated. Additionally, it showed that the over 50% of the total zones had significant damage estimation errors when the extreme value analysis methodology is applied. Further study for the reliable damage estimation is also necessary.
Study on Measures to Promote Urban Search and Rescue
Lee, In-Sun ; Shin, Ho-Joon ; Baek, Min-Ho ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 143~149
DOI : 10.9798/KOSHAM.2012.12.5.143
Population and economic growth have caused the rapid external expansion of cities with high-rises in the metropolitan area, high-intensity utilization of underground space etc. As cities becoming more complex than ever, an outbreak of natural or manmade disaster would result in damages beyond imagination hence the enhancement of Urban Search and Rescue ability in the damaged area becomes crucial. Korea is in its very early stage as far as the concept and awareness of Urban Search and Rescue is concerned, and the lack of professional education and training facilities has prevented the associated bodies to take strategic responses. This paper defined the notion of Urban Search and Rescue, analyzed the status of national and international organizations, conducted surveys on National 119 Rescue Services team members responsible for the rescue operations to figure out problems of Urban Search and Rescue and proposed possible improvement measures.
A Study on the Use of Rainwater as Water for Fire-Fighting
Gu, Dong-Wook ; Shin, Ho-Joon ; Baek, Min-Ho ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 151~158
DOI : 10.9798/KOSHAM.2012.12.5.151
The irrigation, water-control and environment-related problems are getting serious all over the world recently due to droughts, floods or water shortage. The use of rainwater among other methods is becoming an alternative plan for solving these problems. Along with these environmental changes, the number of fire accidents is increasing every year due to industrial growth and urbanization, and this increase in the number of fire concluded in increase in number of fire-fighting activities. Therefore, the measure to use and revitalize rainwater as water for fire-fighting at the scene of a fire was examined in this thesis.
A Comparative Study on Audio-Direction and Video-Direction of Dispatcher for CPR Trainee in Directing Cardiopulmonary Resuscitation(CPR)
Bak, Young-Seok ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 159~164
DOI : 10.9798/KOSHAM.2012.12.5.159
This is a cross-sectional study intended to draw the effectiveness of dispatcher-based voice-direction and video-direction at an advance stage of a hospital in order to draw a more effective CPR directing method between the previous phone CPR direction and the new and active dispatching method-based voice-direction and video-direction. 80 fire officers working at the fire head-quarters in Daejeon participated in the study. While it was average 4.28 for voice-direction, it was 6.23 for video-direction, which showed that video-direction had the significantly higher performance than voice-direction in managing the airway. Voice-direction was average 3.73, whereas video-direction was average 6.15 in performing CPR as well, which showed that video-direction had statistically more positive outcomes than voice-direction. The result of the cardiac massage was also showed that voice-direction was average 4.90 whereas video-direction was average 6.55, which showed a statistically significant difference proving that video-direction had better outcomes than voice-direction. However, it was 17.62% for voice-direction and 18.68% for video-direction in the basic respiration accuracy without a statistically notable difference between them. For pressure accuracy of the cardiac massage, it was average 47.33% for voice-direction and average 77.43% for video-direction implying that video-direction had the higher pressure accuracy than voice-direction. For the time took for respiration and pressure, video-direction had a reduced performance time compared to voice-direction.
Effects of Workload on Human Body Wearing Fire Protective Clothing and Respirator
Bang, Chang-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 165~169
DOI : 10.9798/KOSHAM.2012.12.5.165
The aim of study intends to investigate effects of workload on human body wearing fire protective clothing and respirator and to provide the base data for the safety of firefighter. The results of the study are as follows; Mean skin temperature appeared
under workload 4 METs and
under workload 8 METs and the results were not statistically significant. Heart rate appeared 134.4 bpm under workload 4 METs and 169.7 bpm under workload 8 METs and the results were statistically significant. Respiration Rate showed 32.4 bpm under workload 4 METs and 37.6 bpm under workload 8 METs and the results were not statistically significant. Weight Loss showed 0.2 kg under workload 4 METs and 0.5 kg under workload 8 METs and the results were statistically significant. It was concluded that physiological responses of human body varied considerably and reflected by increase of workload.
A Comparative Study on Effects of Human Body Wearing Various Fire Protective Equipments
Bang, Chang-Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 171~176
DOI : 10.9798/KOSHAM.2012.12.5.171
The aim of study intends to investigate a comparative study on effects of human body wearing various fire protective equipments and to provide the basic data for the safety of firefighter. The results of the study are as follows; After the experiment wearing various fire protective equipments as shorts, fire protective clothing, fire protective clothing and SCBA, heat protective clothing, mean skin temperature, tympanic temperature, heat rate, thermal sensation and RPE due to case of wearing fire protective clothing and SCBA are statistically significant higher, The weight loss due to case of wearing heat protective clothing is statistically significant higher. It is concluded that physiological responses of human body varied considerably and reflected by various fire protective equipments.
A Study on the Construction Methods for a Fire Extinguisher Recycling System
Lee, Eui-Pyeong ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 177~184
DOI : 10.9798/KOSHAM.2012.12.5.177
A fire extinguisher is an important initial extinguishing equipment which should assure accurate extinguishing performance in a fire. Thus, the products which get the model approval of fire equipment and pass the pre-product inspection by the Korea Fire Institute of Industry & Technology only can be produced and sold. Although such a strict national fire equipment inspection system is applied to the fire extinguisher, there are no legal controls or guidelines on its recycling. This study analyzes the situations and problems of disposal of waste fire extinguishers and the need of a fire extinguisher recycling system and examines the possibility of fire extinguisher recycling in terms of technology and legal systems. Moreover, some suggestions are made: the establishment of a recycling guideline of fire extinguishing agents, the development of recycling technology, the creation of the fire extinguisher recycling industry(types of business), the collection of old fire extinguishers, the construction of a fire extinguisher recycling system, and the establishment of a recycling plant.
Study of the Characteristics of Forest Fire Based on Statistics of Forest Fire in Korea
Lee, Myung-Woog ; Lee, Si-Young ; Lee, Jong Ho ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 185~192
DOI : 10.9798/KOSHAM.2012.12.5.185
Forest fires occurred in Korea during past 50 years showed a lot of periodic changes according to the environmental changes. Average occurrences and the damaged area by the forest fires numbered 451 times and 3,760ha a year, respectively. The damaged amount of trees and values were largely increased by the expansion of aged trees growing area along with 1st and 2nd Essential Plan for Forest and by the large-scaled forest fires occurred in 90s and 2000s. The damages were sharply increased since 90s. The number of occurrences and damaged areas according to the region and the control division showed some variant results, but the numbers related to Kyungbuk and Kangwon region noticeably large in compared to the other regions. For Kangwon region, the damaged areas were larger in spite of the occurrences because of the large-scaled forest fires in 90s and 2000s. The statistics represents that carelessness by mountain-goers was the top cause of the origin of fire. The number was 30% in 60s and 70s, but was increased to 50% after 80s. The most frequent month of forest fire had been April, however the tendency showed that increasing the frequency in March and November but decreasing in April during 80s. 15% of the total of forest fire had occurred on Sunday, but the forest fire rate sharply increased on Friday and Saturday after the introduction of five-day workweek since 2000s. For hourly base, the forest fire occurred around 14:00~18:00(2~6PM) of 50%, and around noon(11:00~13:00) of 35%. However, the occurrence of forest fire in the afternoon were decresed steadily, and the forest fire which occurred noon, morning, and night were relatively increased. The forest fire rate of night time was represented the highest among them.
A Study on the Perception of Government Employees on Forest Fire Danger between Forests and Main Facilities within Forest Areas
Lee, Si-Young ; Yeom, Chan Ho ; Kwon, Chun Geun ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 193~198
DOI : 10.9798/KOSHAM.2012.12.5.193
This study conducted a survey targeting government employees from the Korea Forest Service, Local Autonomous entities, and Fire Department in order to research the perception on the separation distance between forests and main facilities within forest areas, and the results showed that 94.3% of the three organizations perceived that a separation distance must be kept, and in case separation distances are not acquirable, it was perceived that the expansion of forest fire surveillance camera systems are necessary as a forest fire prevention method.
Comparison of RUSLE and LISEM for the Evaluation of Spatial Distribution of Simulated Sediment Yield
Im, Sung Soo ; Kim, Minseok ; Kim, Joong Hoon ; Paik, Kyungrock ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 199~206
DOI : 10.9798/KOSHAM.2012.12.5.199
Various models have been developed for the estimation of spatial distribution of sediment yield. However, they often generate distinct results because of differences in their development purposes and calculation processes. Therefore, it is challenging to verify the simulation result without ground measurements of spatially varying sediment fluxes. Here, we postulate that applying multiple models to a same watershed and checking whether they provide similar spatial distributions can be an indirect method of evaluating the performance of the models. To test this idea, we apply two models of LISEM and GIS-based RUSLE for a small watershed in Gyeonggi-do, South Korea, where actual sediment yield was measured at the outlet. Two models result in similar spatial patterns in the distribution of sediments yield. LISEM results show more evenly distributed sediment yield. This difference is partly due to the difference in model structures and due to the ranges of parameters chosen between the two models. Compared to RUSLE, there are limited references for model parameter values of LISEM in Korean practices. Helped by physically-based model structure, LISEM is expected to simulate sediment yield in a more reasonable manner, compared to RUSLE, once the appropriate ranges of model parameters are suggested in the future.
An Improvement on Estimation of Runoff Factor Equation for Mountain Area in MUSLE
Won, Jin Young ; Lee, Jong Seol ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 207~214
DOI : 10.9798/KOSHAM.2012.12.5.207
Williams developed the Modified Universal Soil Loss Equation(MUSLE) by replacing the rainfall energy factor in USLE with runoff energy factor, which was expressed in the function of total runoff volume Q and peak discharge
with the form of
. The coefficients
were derived from individual rainfall data of 47 basins and largely depended on the hydrological characteristics of the basins. Therefore, it may occur the inappropriate results when the runoff factor recommended in MUSLE are applied to the basins in Korea without a validation. The purpose of this study is to present the runoff model and the coefficients of the runoff factor which are suitable for mountainous basins in Korea. We used 32 rainfall runoff and sediment yields data measured from 3 small mountainous basins in Korea. In order to achieve our purposes, the total runoff and peak discharge by SCS, Nakayasu, and Clark model were compared with measured data. And the correlation analysis between calculated and measured runoff factor was performed. The results showed that the suitable model for small mountainous basins was Nakayasu model and the range of coefficients
was 0.61~6.87 and 0.98~1.02 respectively. And the equation of
was suggested as the runoff factor in application of MUSLE to small mountainous basins in Korea. For the purpose of the verification, the runoff factor suggested in this study was applied to another basins to estimate sediment yields, and the results showed that the application of the newly suggested runoff factor was more reasonable than that of the runoff factor suggested by Williams(1975).
Estimation of Infiltration Curved Formulas by using Infiltration Capacity Experiment in the Hongcheun-River Watershed
Kang, Young Bok ; Kim, Bong Jin ; Park, Soo Jin ; Choi, Han Kuy ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 215~223
DOI : 10.9798/KOSHAM.2012.12.5.215
This study provided the value of infiltration capacity by soils after taking experiments of initial infiltration capacity on 29 sites from 18 soil series that were selected from the area of Hongcheon River. According to the result of our study, there is no significant difference between the field and the paddy in terms of initial infiltration capacity, but there is a huge difference between woods and the earth. Then, we suggested a curve formula of infiltration capacity on soil series that have a high defining coefficient based on the data from our study. In the end, we compared effective precipitation by methods of measuring it. The result of this comparison suggested that water is spilled intensively in the latter half of raining when Horton's method is used, and water is spilled from the beginning and is spilled more in the latter half when NRCS is used. The value of effective precipitation was calculated less when Horton's infiltration capacity curve formula was used than when NRCS's AMC-II conditions were applied.
Determination of the Optimal Pipe Dimeter for Irrigation Network using Binary Integer Programming and Developmenr of the Database for Design Standard
Chung, Gunhui ; Kim, YoungHwa ; Jeon, GeonYeong ; Kim, Joong Hoon ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 225~231
DOI : 10.9798/KOSHAM.2012.12.5.225
The interest on the irrigation pipe network systems have been increased. The irrigation pipe network is not affected by the topography and possible to enough supply. Therefore, the network system is applied in the large scale agricultural complex. In this study, a model to optimize pipe diameters was developed to supply enough irrigation water efficiently in the branch type pipe network. The developed model was applied in a agricultural complex with several water demands, hydraulic head in the starting nodes, hydraulic gradients in the different types of the irrigation sector. The optimized pipe diameter was proposed for the standardization of the design. The decision variable of the conventional method was the length of the pipes to linearize the optimization system. In the method, more than two sizes of the diameter were proposed, which was not realistic. Therefore, in this study, the new optimization method was suggested using binary integer programming whose decision variables are the binary number to represent that the pipe with the proposed diameter was installed or not. The design standard was proposed using the simulation results from the sensitivity analysis. The result is used to find the optimal pipe diameter without the model simulation if the type of sector and water demand are known, which is very economic design for the future agriculture area.
The Optimal Analysis of Data Preprocessing Method for Clustering the Region of Precipitation
Kim, Ug-Gi ; Ahn, Won-Sik ; Lee, Chae-Young ; Um, Myoung-Jin ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 233~240
DOI : 10.9798/KOSHAM.2012.12.5.233
In this study, the data preprocessing methods were analyzed to obtain the optimal clustering solution in South Korea. The geographic data and weather data in 75 stations of Korea Meteorological Administration are applied. The applied data preprocessing methods are general normalization, modified normalization, standardization and factor analysis. After the clustering analysis were conducted by K-mean method with preprocessing data, the efficiency of data preprocessing methods are estimated using the clustering index, such as Dunn index and Silhouette index. The clustering analysis are carried out as the cluster number changes from 3 to 9. Among the data preprocessing methods, the data by factor analysis shows the best efficiency for clustering analysis. However, it is not enough to find the optimal cluster number.
Analysis of the Wave Energy Reduction Effect by Different Artificial Riprap Arrangement
Kim, Ha Yong ; Han, Ki Jang ; Jeong, Sang Man ; Kim, Kee Dong ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 241~249
DOI : 10.9798/KOSHAM.2012.12.5.241
The locally constructed revetment structures for coastal protection are presently made of imprevious concrete materials. However, the wave energy reduction effect of present revetment structures are considerably inefficient which yields to bed scouring and thus, collapsing of the revetment structures. Studies on the analysis of the influence of riprap arrangement on the friction area and void fraction, for wave energy reduction, are insufficient. Therefore, this study analyzed the wave energy reduction effect of various artificial ripraps, made with varying friction area and void fraction, in different riprap arrangements. The results of the analysis showed that the increase of both friction area and void fraction of arranged artificial ripraps yields to a more efficient wave energy reducing material intended for revetment structures.
Numerical Study on Reduced Runup Heights of Solitary Wave by Submerged Structures
Ha, Taemin ; Jung, Wooyoung ; Cho, Yong-Sik ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 251~258
DOI : 10.9798/KOSHAM.2012.12.5.251
Most of coastal structures have been built in the surf zone to protect coastal areas. The transformation of waves in the surf zone, in general, is very complicated and contains lots of hazards to coastal communities. Thus, behaviors of waves in the surf zone should be very carefully analyzed and predicted. Furthermore, an accurate analysis of deformed waves around coastal structures is directly related to construction of economic and safe coastal structures because a wave height plays an important role in determination of weight and shape of a levee body or an armoring material. In this study, a numerical model using a large eddy simulation is employed to predict runup heights of nonlinear waves passed a submerged structure in the surf zone. Reduced runup heights are predicted and the characteristics of runup heights in terms of wave reflection, transmission and dissipation coefficients are investigated.
Accident Analysis by the Fire of Cigarettes
Chung, Yeong Jin ;
Journal of Korean Society of Hazard Mitigation, volume 12, issue 5, 2012, Pages 259~266
DOI : 10.9798/KOSHAM.2012.12.5.259
A fire caused by a cigarette, brings deaths and injuries, personal injury and property damage. Moreover, thereby bringing the increase in the cost of fire suppression, loss of community property and will be a threat to the lives of firefighters. The survey by the National Fire Information System of the National Emergency Management Agency (NEMA) in the last five years (2007-2011), the statistics were analyzed. The result of a fire caused by a cigarette butt and annual average 6,419 cases accounted for 13.9% of the entire fire occurs, damage the lives of average annual 109 (15%), damage to property, the annual average 7,022 million won (2.6%) of damage each year occurred. And publicity through the media and the education system need to notify the fire risk cigarettes, and enlightenment for the people, and because of this is considered to be an effort to minimize the damage on a cigarette fire.