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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 11, Issue 6 - Dec 2011
Volume 11, Issue 5 - Oct 2011
Volume 11, Issue 4 - Aug 2011
Volume 11, Issue 3 - Jun 2011
Volume 11, Issue 2 - Apr 2011
Volume 11, Issue 1 - Feb 2011
Selecting the target year
Evaluation of Shear Behaviour of Void Slabs with Deck
Han, Jun-Hao ; Kim, Sang-Dae ; Kim, Sang-Mo ; Ju, Yong-Ku ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 1~7
DOI : 10.9798/KOSHAM.2011.11.4.001
Shear behaviour of void slabs with deck is experimentally analyzed in this study. The specimens were tested by pushover test with parameters of the existence of void, and the depth of the slab. As a result, the shear capacity of the standard specimen with void were reduced to 67% of the solid specimen. The expectative shear capacity can be calculated with 45 degrees inclined effective concrete area at critical distance d except void area.
An Evaluation on the Shear Capacity of Void Slabs with Prestressed Half PC
Jang, Hye-Jin ; Kim, Sang-Dae ; Ju, Young-Kyu ; Kim, Sang-Mo ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 9~15
DOI : 10.9798/KOSHAM.2011.11.4.009
To obtain a lower story height and reduce the weight of a building structure, the void slabs are proposed. Since it can make a long span and a decrease of
emission by reducing the self weight of the slabs, it gives a lot of advantages. To improve the construction and performance of void slabs, the new system is developed by combination with the prestressed half PC slabs system. In this study, it is subject to estimate the shear capacity through the proposal concerning shear design and the test result to evaluate applicability of new two way void slabs system with prestressed half PC in practice. A total of 4 full scale specimens were producted. From the results of this test, the shear strength of the void slabs with prestressed half PC had lower capacity than solid slabs. And the result showed that to apply the prestressed wire and place more shear keys in slabs made a higher strength. The developed void slabs, therefore, can be designed and evaluated by current design code safety with reduction factor.
A Simplified Analysis for the Steel-Concrete Decks by the Bond Model
Yi, Gyu-Sei ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 17~21
DOI : 10.9798/KOSHAM.2011.11.4.017
In this study, a bond model, which is used to evaluate the behavior of the steel-concrete decks, is proposed. The load-end slip relation in the proposed model is formulated by Newmark theory. The steel-concrete decks are analyzed by finite element analysis with the aid of the proposed bond model. In the finite element analysis, the shear connectors between the steel plate and the concrete are modeled by a number of spring elements. The results of the finite element analysis with the proposed bond model are fairly correlated with the experimental results of the full-size model. This study furthermore indicates that, if the proposed bond model is properly used in the analysis of steel-concrete composite deck, the behavior of the composite deck can be easily analyzed without the aid of the full-size experiment.
Analysis of Reynolds Number According to Section Scale
Lee, Ho-Yeop ; Chun, Nak-Hyun ; Kim, Young-Min ; Lee, Hak-Eun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 23~29
DOI : 10.9798/KOSHAM.2011.11.4.023
Reynolds number similarity is basic theory of aerodynamic test. Over specification Reynolds number, It isn't seem to have much regard for this effect. But it is important factor that should never be missed out on real aerodynamic test. We have to seriously consider this factor when planning aerodynamic test. Reynolds number is important non-dimensional factor that defined fluid viscosity, relative velocity and characteristic length. At two dimensional section model test, there is a special characteristic that air velocity and characteristic length is changed according to section scale. And from this characteristic, Reynolds number is changed. Using this special characteristics, we measure aerodynamic coefficient on aerodynamic test by varying the Reynolds number through two dimensional section model test and analysis sensitivity of Reynolds number. Finally, verify this aero dynamic coefficient by comparing with test data with CFD program analysis data.
Dynamic Analysis of a Wheel force for a Running High-Speed Vehicle on Railway PSC Box Girder Bridge
Oh, Soon-Taek ; Lee, Dong-Jun ; Shim, Young-Woo ; Kim, Han-Su ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 31~39
DOI : 10.9798/KOSHAM.2011.11.4.031
A dynamic analysis procedure is developed to provide a comprehensive estimation of the dynamic responses of locomotive's wheels running over a Pre-Stressed Concrete (PSC) box girder bridge on the Korea high speed railway. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyze accurately and evaluate with in-depth parametric studies of the bridge lengths (25, 30, 35, 40 m) for dynamic responses of railway vehicle wheel forces due to the critical crossing speeds (300~315 km/h) on the bridges. The high-speed railway locomotive (KTX) is used as 38-degree of freedom system. Three displacements (vertical, lateral and longitudinal) as well as three rotational components (pitching, rolling and yawing) are considered in the 38-degree of freedom model. Three dimensional frame element is used to model the PSC box girder bridge, simply supported span length of 40m. The irregulation of rail-way is derived using the exponential spectrum density function under assumption of normal probability procedure. The results of dynamic analysis by Runge-Kutta method which are able to analyze considering the dynamic wheel forces between bridges and normal rail-ways are compared and contrasted. It is presented as an wheel forces spectrum that is varying either the bridge lengths or the critical crossing speeds.
The Weighting Factor Assessment for Water Supply Facility Management Using Analytic Hierarchy Process
Kim, Eung-Seok ; Choi, Hyun-Il ; Kim, Sung-Pyo ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 41~47
DOI : 10.9798/KOSHAM.2011.11.4.041
The purpose of this study is to assess weighing factors which can help to manage six water supply facilities (water intake facility, pipe network, water treatment facility, pumping station, control and distribution facility) by local government. The management of water supply system can be largely affected by the area, location and land use characteristics. In this study, questionnaire was distributed to a specific local government for evaluating relative weighing factors of six water supply facilities. The delphi method was adopted for the survey and the results was analyzed by the analytic hierarchy process(AHP) method for estimating weighing factors in each facility. As the analysis results, priority facility was determined among six facilities in each twelve water works. In addition, the potential application of the analysis results in water supply facilities which are needs to be newly-constructed or maintained is suggested.
Experimental Study of Back and Forth Motion using Tire Tracking Machine
Sung, Ik-Hyun ; Park, Jong-Sup ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 49~55
DOI : 10.9798/KOSHAM.2011.11.4.049
In this paper, an experimental study is performed in order to determine the effects of interaction between vehicle and structure. For this purpose a wheel tracking machine and an adequate single span bridge are designed. Wheel Tracking Machine is consists of real rubber tire and adequate Mass and weight. Results presented in the paper show that an real vehicle internal forces including interaction between vehicle and structure produce additional effects on dynamic behavior of structure including reversal and contrary behavior.
Estimation of Acceleration factor for Tracking Test Machine and Loop type Precast Deck
Sung, Ik-Hyun ; Yi, Gyu-Sei ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 57~63
DOI : 10.9798/KOSHAM.2011.11.4.057
This Paper presented in the behavior of Loop connected Precast panels under the Tracking machine with real truck tire. For this purpose a wheel tracking machine and adequate precast concrete deck single span bridge are designed. For the purpose of dynamic behavior in the precast panels, at first we take moving vehicle's longitudinal displacement data. and make estimated acceleration factor for test specimen. Results presented in this paper show that interaction between vehicle and structure produce additional dynamic effects of structure and various motion of traffic loading cases on the deck.
Improvement of the Tension Estimation Method for Extradosed Bridge Cables
Choi, Dong-Ho ; Park, Wan-Soon ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 65~72
DOI : 10.9798/KOSHAM.2011.11.4.065
Estimating the exact tension force of cables is very important to the construction and maintenance of the cable bridges. The cable tension changes continually from the first installation to the final construction stage. Moreover, in service status, this changes continuously as the vehicle loads change. Recently, many extradosed bridges are constructed and these bridges have the heavy and thick cables. But the existing formulas do not give the reliable estimations for these bridges because these formulas do not consider the tension force induced by self-weight (gravity effect). In this study, the gravity effect on the extradosed bridge cables is investigated and an improved estimation method considering the gravity effect is proposed. The relationship among the gravity effect, the natural frequency and the slenderness ratio is also clearly explained. The field test results show that the new method has the acceptable reliability compared with the existing methods for the extradosed bridge cables.
Temporal and Spatial Variability of Precipitation and Daily Average Temperature in the South Korea
Lee, Won-Hyun ; Hong, Seong-Hyun ; Kim, Youn-Gyu ; Chung, Eun-Sung ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 73~86
DOI : 10.9798/KOSHAM.2011.11.4.073
This study analyzed the recent changed temporal and spatial variations of precipitation and daily average temperature in the South Korea. 65 weather stations were grouped, based on their latitudes and longitudes and the recent variable temporal and spatial variations of each latitude and longitude were derived, quantitatively. In addition, the Mann-Kendall trend analysis was used to determine the tendency (upward/downward/no trend) of rainfall and temperature. From these analyses, it was shown that the precipitation of zone 1 (
) has increased by 7% and the rate of increase showed 5%~18% as the latitude went up. During summer, the rate of precipitation increase has increased as the latitude went up. Due to the rapid increase of summer, the rate of precipitation increase has increased as the longitude went up. On the whole, average temperature has been increased as the latitude went up. The Mann-Kendall trend analysis derived that the temperature of South Korea has increased except zone 2 (
)and summer period and the precipitation on latitude
has increased during summer. Since this study showed the recent climate change trend in detail, it will be a preliminary data for the research of climate change adaptation.
Development of HAZ-RAM for reducing HAZMAT transportation accident
Chung, Sung-Bong ; Kim, Yeon-Woong ; Park, Min-Kyu ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 87~94
DOI : 10.9798/KOSHAM.2011.11.4.087
The accident of HAZMAT causes not only physical damage but also secondary accidents which makes negative effects in regional environment and society. Thus, based on a particular management system in HAZMAT transportation, it is necessary to prevent accidents and to minimize secondary damages. According to the accident data, the causes of accidents are human factor(62.8%), physical factor(9.9%), other factors(23.1%) and unknown factors(4.2%). Especially the most accidents related with human factor are caused by neglect of management and surveillance. In this study to minimize the risk caused by human factor, HT-RAM(Hazmat Transportation Risk Assessment Matrix) was developed using current RAM(Risk Assessment Matrix). For developing HT-RAM effectively, the following 3 factors are also considered. First, the type of HAZMAT accident is defined and classified. Secondly, the severity and the frequency are analyzed by accident type. Finally, the plan for management in transportation was suggested to reduce the risk and accident. In the future, HAZ-RAM developed in this research is applied to the HAZMAT transportation management system, it will reduce not only traffic accident but also the secondary damage caused by the accident.
Analysis on Public Risk Perception and Environmental Risk
Hwang, Seong-Nam ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 95~102
DOI : 10.9798/KOSHAM.2011.11.4.095
This research examined how Scientifically Estimated Environmental Risks (SEERs) of floods, hurricanes, and hazardous material releases are related with perceived risks of those hazards. This study also tested the relationship between household characteristics and environmental risk perceptions. Major findings of this research are as follows. First, there were little differences in risk perceptions of natural and technological hazards across demographic groups. Specifically, the respondents' risk perceptions of both natural and technological hazards did not differ by age, household size, and marital status. By contrast, educational level, gender (male =1), and median household income were statistically related to perceived risk of the natural hazards, whereas educational attainment and gender were statistically related to perceived risk of hazardous material releases. Finally, SEERs of floods and hurricanes were positively related to respondents' perception of property damage, but not related to injury or heath problems from those natural hazards. SEER of hazardous materials was related to all three categories of risk perception of a hazardous material release. These results suggest that environmental cues such as proximity to rivers and bays do not much contribute to an increase in the respondents' perception of safety and health problems resulting from natural hazards. The fact that there was a significant correlation with property damage suggests that risk area residents believe that they can protect themselves (e.g., by evacuating), but not their property.
A Study on the Mechanism through Reproduction Experiments of Water Purifier Fire
Lee, Jung-Il ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 103~108
DOI : 10.9798/KOSHAM.2011.11.4.103
Today, most people work and home, through the water purifier has been resolved. Depending on seasonal changes and personal taste of coffee, if you can enjoy a snack and water purifier is a restaurant, lounge, public areas and focusing on the rapid spread of the fire, water purifier as compared to the total number of fires increased by 0.03% per year trend on, but the washrooms fire and fire-related research data and case studies with analysis of the exact cause lack of proper preventive measures are insufficient reality. This study focused on the water cooler to understand the structure and principles of fire, fire out a mechanism to review the weak factors should contribute to fire prevention.
A Study on Automatic Foam Mixing Characteristics of Pump Proportioner in Steady State to Enhanced the Performance of Foam System for a Fire Truck
Ku, Jae-Hyun ; So, Soo-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 109~113
DOI : 10.9798/KOSHAM.2011.11.4.109
This study describes to analyze automatic foam mixing characteristics in steady state in order to enhance the performance of pump proportioners of foam system for a fire truck, which is designed to mix accurately a foam liquid concentrate into a water stream up to constant concentration. The developed pump proportioner is experimentally evaluated on performance evaluation system consisted of a pump, tanks, a controller, a foam control valve, pressure gauges, flow meters and a nozzle. As a result, the foam mixing performance of the pump proportioner is found to improve with increased the water flow rate due to the venturi effect and with increased the inlet pressure of a pump proportioner and is analysed with 3% and 6% in the error rate of
. Therefore, the pump proportioner system developed for fire trucks showed good performance for automatic foam mixing of foam systems in steady state.
A Study on Improvement of Arson Cause Investigation System in Korea
Ko, Gi-Bong ; Lee, Si-Young ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 115~121
DOI : 10.9798/KOSHAM.2011.11.4.115
This research paper examined the system of investigating the causes of arson and derived related problems and remedies to them. The results of this research showed that the institutions related to the investigation of the causes of arson are fire stations, the police, and insurance companies. However, it was found that fire stations transfer the cases suspected of arson on the scene of a fire to the police for the reason that they have no judicial power, and the police do not positively treat the cases since if they fail to capture arsonists, their work performance is affected and insurance companies do not take part in the investigation of the causes of fire from the beginning due to the lack of information about arson. In order to remedy these problems, it was found to be necessary to establish and operate task force for wide area investigation of the causes of arson, secure the jurisdiction in the investigation of fire, establish tentatively named "National Fire Scientific Research Institute", establish exclusive departments for statistical analysis of arson, reinforce specialized education system for the causes of arson, and form a consultative group for investigation of the causes of arson.
The Vulnerability Assessment of Forest Fire in Gangwon Province Using CCGIS
Chae, Hee-Mmun ; Um, Gi-Jeung ; Lee, Si-Young ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 123~130
DOI : 10.9798/KOSHAM.2011.11.4.123
Since forest sector is increasingly affected by climate change and a forest fire, one of forest disasters, makes a huge impact on a forest ecosystem and regional people's life in general, the vulnerability assessment of forest fires is extremely important. Gangwon province area was selected for the study. Eighty one percent of Gangwon province's land is covered by forest, and 8 cases of big fire, over 300 ha occurred from 2000 to 2009. The vulnerability assessment has been carried out with a help of CCGIS program developed by National Institute of Environmental Research. Climate Exposure Index, Sensitivity Index, Adaptation Capacity Index were employed to evaluate the vulnerability of Gangwon province's forest fire. It turned out that East Sea area of Yeongdong was highly vulnerable to forest fire and various meteorological factors could be involved. The future vulnerability of forest fire in Gangwon province would increase even though the regional difference could exist. The results of the study will be used to establish Gangwon province's adaptation policy for the forest sector.
Effects of Loading Rate and Water Saturation on the Fracture Toughness of Rocks
Jung, Woo-Jin ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 131~135
DOI : 10.9798/KOSHAM.2011.11.4.131
The fracture toughness of rock was measured by Chevron bend Tests. In order to make sure the effects of loading rate and water saturation on the fracture toughness of rocks, Chevron bend tests under static and impact loading using three different types of rocks in both saturated and dry states. In the Impact loading test, the loading rate was adjusted by changing the drop-height of a drop hammer. the testing results showed that dynamic fracture toughness of rocks increased significantly with increasing loading rates. Water saturation induced a substantial decrease in both the dynamic and static fracture toughness of Tage tuff, while we could no significant difference between dynamic and static fracture toughness for Kimachi sandstone and Inada granite between dry and saturated states.
Comparison of Behavior of Earth Slopes Reinforced with Soil Nail
Lee, Seung-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 137~141
DOI : 10.9798/KOSHAM.2011.11.4.137
Full scale field load tests were conducted on two kinds of slopes reinforced with soil nail. One of the two slope is the slope with surface treated by shotcrete. The other slope has a surface placed by precast concrete panel. By comparing load-settlement curves, load bearing capacity for the case of pecast concrete panel was bigger than that for the case of shotcrete. Settlemet distribution of loading plate for the case of precast concrete panel was similar to that for the case in which flexible footing lies on sand. Settlement for the case of shotcrete was bigger than that for the case of the precast concrete panel and also was the differential settlement. By considering overall the test data of all the measurements related with load cell, strain gauge, settlement of loading plate and inclinometer, precast concrete panel has the advantage of load sharing in larger area and restriction of local displacement to the shotcrete treated case.
The Reinforcing Effects of Reinforcing Material in Umbrella Arch Method to Tunnelling
Lee, Jea-Dug ; Choi, Yong-Sung ; Kim, Byoung-Il ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 143~150
DOI : 10.9798/KOSHAM.2011.11.4.143
This paper deals with the reinforcing effects of the reinforced material in the Umbrella Arch Method(UAM). Recently, UAM has been commonly used in Korea to decrease ground movement around a tunnel and stabilize the surface structure adjacent to a tunnel in tunnel construction. In this study, 3-dimensional finite element analyses were carried out for two ground conditions(soil and weathered rock) and for several overburden depths and installation angles of a reinforced material. But ground improvement by grouting was ignored. Displacements at the front of the tunnel crown were obtained from numerical analysis, and the behavior angles in the tunnel face were calculated by using the displacements. The results showed that settlement by tunnel excavation was increased with the increase of overburden depth but was decreased with the increase of overlap length of the reinforced material.
A Study on Mechanical Property of Lightweight Foamed Concrete Using the Silica Fume and Application in Embankment
Woo, Hyeun-Jun ; Yeom, Tae-Jung ; Cho, Kook-Hwan ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 151~156
DOI : 10.9798/KOSHAM.2011.11.4.151
Lightweight Foamed Concrete is one of the most-used materials for insulation of building and embankment. Since it is economic and workability of construction. However, it is not widely used in civil engineering area. Although several researches were performed to investigate material properties of light weight foamed concrete, it is still remained in unexplored field. In this research, laboratory tests were performed to figure out the material properties of light weight foamed concrete to use embankment. The compressive strengths varying with mixing ratio with water and sand as well as silica fume were compared each other. According to research results, the optimum mixing ratio to use embankment material is suggested and the compressive strength using the results is also defined. The adaptability of light weight foamed concrete as an embankment material is checked with design spec and verified.
Variation of Shear Strength of Unsaturated Weathered Granite Soil with Degree of Saturation and Disturbance at Dongrae, Inje and Yeonki sites
Kim, Yun-Tae ; Shin, Ho-Sung ; Park, Dug-Keun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 157~162
DOI : 10.9798/KOSHAM.2011.11.4.157
This study investigates the effects of degree of saturation (or water content) and disturbance on the strength reduction for both disturbed and undisturbed samples of weathered granite soil using direct shear test. Several series of direct shear tests were carried out on undisturbed or disturbed samples with 5 different degrees of saturation ranging from 0 to 100%. The direct test results showed that the values of cohesion reduction ratio (CRR) of weathered granite soil were in the range of 45 - 82 %, while the values of friction angle reduction ratio (FRR) in the range of 6 - 11%. Apparent cohesion and friction angle of weathered granite soils also decreased with an increase in degree of saturation. The results indicated that shear strength of unsaturated weathered granite soil at Dongrae, Inje and Yeonki sites tends to reduce due to an increase of water content induced from rainfall infiltration and/or due to disturbance of soil structure.
Analysis of the Preventive Investment Effect of Small Stream Improvement
Ahn, Tae-Jin ; Lee, Joo-Heon ; Lee, Seung-Oh ; Cheong, Tae-Sung ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 163~169
DOI : 10.9798/KOSHAM.2011.11.4.163
In this study, the necessity and significance of the small stream improvement project are suggested after the quantitative analysis on ROI(Return on Investment) of disaster prevention since abolishing and changing of transfer fund, which was a part of the small stream improvement project cost in 2005. Total 60 small streams were selected to investigate the disaster records and rainfalls, and analyzed ROI of disaster prevention using historical disaster records in this study. Also, investigation items were specified relating with water utilization, environments, flood control, and revetment safety on 52 small streams, already completed the small stream improvement. Results from this study will be able to contribute to the compilation of budget in the central and local governments.
Preliminary Analysis of the Relationship between Annual Precipitation and Vegetation using MODIS NPP Remotely Sensed Data in Korea
Choi, Dae-Gyu ; Choi, Hyun-Il ; Kim, Sang-Dan ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 171~178
DOI : 10.9798/KOSHAM.2011.11.4.171
Growth of vegetation is closely related with water cycle process. Especially, precipitation is a key factor in inter-annual variability of vegetation. However, there is no quantitative approach to examine the relationship with vegetation and precipitation in Korea. Net Primary Production (NPP) is the difference between organic matter by photosynthesis and respiration. It is commonly used as representative of vegetation quantity. In this study, we used 5 year data of NPP and precipitation from 50 sites across Korea. Even though period of data is too short to define the relationship and NPP data has an uncertainty, our results showed that there is a strong relationship (
>0.6) between NPP and precipitation at each site. However considering all sites, its correlation is decreased (
=0.310). We also analyzed the relationship between the Rainfall Use Efficiency and Annual Rainfall, the relationship was not shown clear relationship as determination coefficient, 0.025. The findings in this paper are that it is not easy to show general relationship which can explain Korean vegetation but locally, some places are revealed strong relationship between NPP and precipitation. Therefore locality should be reflected when developing the hydrological model included the ecological components in Korea.
Spatial Analysis of Rain Gauge Networks: Application of Uniform and Poisson Distributions
Yoo, Chul-Sang ; Lee, Ji-Ho ; Yang, Dong-Min ; Chung, Jae-Hak ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 179~187
DOI : 10.9798/KOSHAM.2011.11.4.179
This study compared spatial distribution characteristics of three nationwide rain gauge networks of Ministry of Land, Transportation and Maritime Affairs (MLTM), Korea Meteorology Agency (KMA), and local governments. As methodologies, both quadrat method and nearest neighbor method were applied along with Poisson and uniform probability distributions of interest. As results, the AWS network of KMA was found to show characteristics near the uniform distribution, and that of MLTM the Poisson distribution. That of local governments was found to be in between the other two. Among various purposes of operating rain gauge networks, those following the uniform distribution have an advantage of estimating the areal average rainfall, and others following the Poisson distribution an advantage of estimating the spatial correlation structure of rainfall field.
Analysis of Spatially Distributed Risk for Regional Disaster Management: 1. Hazard and Exposure
Park, Moo-Jong ; Park, Min-Kyu ; Song, Young-Seok ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 189~199
DOI : 10.9798/KOSHAM.2011.11.4.189
In this study, rainfall, temperature and population data at 59 cities over the Korean peninsula are spatially analyzed for the assesment of hazard and exposure of the regional disaster management. The EOF (empirical orthogonal function) analysis for spatial distributions of rainfall and temperature is applied. Youngdong region in Gangwon province was the most hazardous area when considering rainfall and temperature. However, the exposure factor, population is relatively greater in the metropolitan cities including Seoul. In order to assess the factors causing floods, the annual maximum rainfall depth series and the annual maximum storm event series are also analyzed using the EOF analysis. The annual maximum rainfall series include 1 hour as the short duration and 24 hour as the long duration. The short duration maximum rainfall depth occurs at Jiri mountain region and it was analyzed as the reason for that phenomenon that the big intensity of the annual maximum storm event is focused around this area. The long duration maximum rainfall depth occurs at the northern area of Gyeonggi province, Yongdong region in Gangwon province and the region near the South sea. It is associated with this phenomenon that the duration characteristics of storm events have the strongest persistence at these areas.
Analysis of Spatially Distributed Risk for Regional Disaster Management: 2. Vulnerability
Park, Min-Kyu ; Park, Moo-Jong ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 201~209
DOI : 10.9798/KOSHAM.2011.11.4.201
The observed rainfall data at 59 stations over the Korean peninsula are analyzed for the assesment of the vulnerability for the regional disaster management. The rainfall with return periods and the PMP (probable maximum precipitation) were evaluated for their spatial distribution. Annual maximum rainfall series were spatially analyzed also. The frequency factor of the rainfall with 100 year return periods and PMP was reviewed together. These comparison shows more vulnerable area which the frequency factor of PMP is relatively bigger than other area. Adjustment of the return periods has been a commonly used measure to reduce the vulnerability. The influence of the adjustment into the variations of the rainfall depth was examined to determine the relationship between different return period conditions.
Variations of Weather Stations Characteristics to Recent Climate Change Using Rainfall and Average Daily Temperature Data
Kim, Youn-Gyu ; Hong, Seong-Hyun ; Lee, Won-Hyun ; Chung, Eun-Sung ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 211~219
DOI : 10.9798/KOSHAM.2011.11.4.211
This study analyzed the characteristics of 65 weather stations of Korea using rainfall and average daily temperature data and compared differences between before 2000 and after 2001. By seasons, all weather stations were divided into 9 groups depending on their rainfalls and temperatures. Also, the Mann-Kendall trend analysis was used to determine the tendency(upward/downward/no trend) of rainfall and temperature. From these analyses, recent temperature increases appear during spring, fall and winter period and rainfall increase have occurred during summer. Rainfall upward trend appeared in the region of central interior part and four more stations showed the same trend after 2001. For temperature, most coastal area showed the strong upward trend, but 11 weather stations of interior region showed the upward trend during the summer.
Development of a Long-term Rainfall Generation Method for Long-term Runoff Simulations Considering the Recent Rainfall-Runoff Characteristics
Lee, Jung-Ho ; Ryu, Seong-Su ; Kim, Joong-Hoon ; Jun, Hwan-Don ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 221~227
DOI : 10.9798/KOSHAM.2011.11.4.221
To perform a long-term simulation which can be used for the estimation of annual runoff or other analyses, a long-term rainfall-runoff simulation relies on a continuous daily- or monthly-rainfall data. For this purpose, sufficient observed rainfall time series data must be used to satisfy the reliability of runoff analysis. In Korea, many rainfall stations have enough observed rainfall data for the reliable statistical analysis. However, as the characteristics of rainfall change due to urbanization and climate change, using all the rainfall data including older ones may average out their effects. Therefore, in this study, the year of the rainfall characteristic change was determined by the statistical analysis, and the long-term rainfall data was then generated by the Neyman-Scott model using the more recent rainfall data after the year of the rainfall characteristic change. For the observed rainfall data of 48 years(1961~2008), the Year 1990 was determined as the year of the rainfall characteristic change. Based on this finding, the 100- year daily-rainfall time series were generated by the Neyman-Scott model using the rainfall data observed from 1990 to 2008. Finally, the simulated daily-rainfall time series were verified for the statistical reliability by comparing with the more recent observed data.
Estimation of Urban Inundation Risk using Fuzzy C-Means
Lee, Jung-Ho ; Lee, Won-Woo ; Kim, Joong-Hoon ; Jun, Hwan-Don ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 229~235
DOI : 10.9798/KOSHAM.2011.11.4.229
Generally, inundation risk should be estimated to establish the flood disaster prevention policy in urban areas. In this study, a new method was suggested to estimate urban inundation risk. To develop the suggested method, we selected the five factors such as surface elevation, surface slope, pipe density, population and sediment in pipe, which have influence on the urban flood risk. Although the contribution of each factor to increase the risk must be considered at the same time, it is difficult to combine those contributions because each factor has different units. For this reason, the new method adopts the Fuzzy C-Means (FCM) algorithm which is one of the fuzzy cluster algorithms and makes it possible to consider the contribution of those factors that increase urban inundation risk at the same time. To verify the applicability of the suggested method, we applied the suggested method to Gunja basin in Seoul, Korea. Firstly, we collected the five factors for each sub-basin and used them to perform the FCM to estimate the inundation risk of each sub-basin. Then, the results obtained from the analysis were compared with the inundation history of Gunja basin. Comparison results showed that the high-risk sub-basins were in good agreement with the sub-basins which have the inundation history. Thus, the inundation risk estimation using FCM can be applicable to establish the disaster prevention policy for urban flood.
Changes of COD fraction According to Nitritation Using Piggery Wastewater
Gil, Kyung-Ik ; Im, Ji-Yeol ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 4, 2011, Pages 237~243
DOI : 10.9798/KOSHAM.2011.11.4.237
To remove high strength ammonium nitrogen in piggery wastewater through stable nitritation and to analyze nitrite conversion rate under the change of operating condition, laboratory scale reactor was operated with stable nitritation process. As the result, it is observed that nitritation is sensitively affected by SRT. Also, the organic matters in the influent and effluent of laboratory scale reactor were classified according to microbial respirometric method. In the organic matter contained in the raw piggery wastewater, Xs is the most part. But effluent of anaerobic digester form piggery wastewater,
is the most part. In case of effluent of laboratory scale reactor, it is observed that the property of the organic matter fraction in the effluent is being changed according to ammonia removal rate and nitrite conversion rate. Through multiple correlation analysis, this finding also would be important data to predict the property of organic matters fraction in piggery wastewater through nitritation process.