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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
A Study on Development and Utilization of Wind Hazard Maps
Lee, Young-Kyu ; Lee, Sung-Su ; Ham, Hee-Jung ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 1~8
DOI : 10.9798/KOSHAM.2011.11.3.001
In this study, a wind hazard map over Korea peninsula based on geographical information is developed, which consists of the surface roughness model, the topographical effect model and the homogeneous wind model. The surface roughness model is assessed to evaluate the effect of the surface roughness on the wind field near ground. The topographical effect model is assessed to quantify the effect of the speed-up caused by topology, which is calculated by adopting the topographical effect factor in Korea building code (2005). The homogeneous wind map is created either by a frequency analysis method for meteorological data or a typhoon simulation. The results show that the wind hazard map can be applied to the determination of insurance premium as well as the assessment of loss and damage.
The Moment-Curvature Relationship of the Rectangular Ultra High Performance Fiber Reinforced Concrete Beam
Han, Sang-Mook ; Guo, Qing-Yong ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 9~15
DOI : 10.9798/KOSHAM.2011.11.3.009
The flexural behavior of the UHPFRC rectangular beam which has 100 MPa, 140 MPa compressive strength were compared with that of the typical RPC rectangular beam which has same geometrical shape, prestressd force and 160 MPa compressive strength. UHPFRC beam was not reinforced at all and the variable of test is fraction of steel fiber, compressive strength of concrete, method of prestressing and ratio of prestressing bar. The behavior of UHPFRC beam was analysed by relationship of moment - curvature and load - deflection. Simple modeling of stress-strain of UHPFRC was proposed. Based on the proposed constituted, the flexural moment-curvature relationship was calculated and compared with experimental data on prestressed UHPFRC beams. Good agreement between calculated strengths and experimental data is obtained.
Mean Field Bias Correction of the Very-Short-Range-Forecast Rainfall using the Kalman Filter
Yoo, Chul-Sang ; Kim, Jung-Ho ; Chung, Jae-Hak ; Yang, Dong-Min ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 17~28
DOI : 10.9798/KOSHAM.2011.11.3.017
This study applied the Kalman Filter for real-time forecasting the G/R (ground rain gauge rainfall/radar rainfall) ratio to correct the mean field bias of the very-short-range-forecast (VSRF) rainfall. The MAPLE-forecasted rainfall was used as the VSRF rainfall, also the methodology for deciding the G/R ratio was improved by evaluating the change of G/R ratio characteristics depending on the threshold and accumulation time. This analysis was done for the inland, mountain, and coastal regions, separately, for their comparison. As the results, more stable G/R ratio could be estimated by applying the threshold and accumulation time, whose forecasting accuracy could also be secured. The accuracy of the corrected rainfall forecasting by the forecasted G/R ratio was the best in the inland region but the worst in the coastal region.
Estimation of Regional Probable Rainfall based on Climate Change Scenarios
Kim, Young-Ho ; Yeo, Chang-Geon ; Seo, Geun-Soon ; Song, Jai-Woo ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 29~35
DOI : 10.9798/KOSHAM.2011.11.3.029
This research proposes the suitable method for estimating the future probable rainfall based in 2100 on the observed rainfall data from main climate observation stations in Korea and the rainfall data from the A1B climate change scenario in the Korea Meteorological Administration. For all those, the frequency probable rainfall in 2100 was estimated by the relationship between average values of 24-hours annual maximum rainfalls and related parameters. Three methods to estimate it were introduced; First one is the regressive analysis method by parameters of probable distribution estimated by observed rainfall data. In the second method, parameters of probable distribution were estimated with the observed rainfall data. Also the rainfall data till 2100 were estimated by the A1B scenario of the Korea Meteorological Administration. Last method was that parameters of probable distribution and probable rainfall were estimated by the A1B scenario of the Korea Meteorological Administration. The estimated probable rainfall by the A1B scenario was smaller than the observed rainfall data, so it is required that the estimated probable rainfall was calibrated by the quantile mapping method. After that calibration, estimated probable rainfall data was averagely became approximate 2.3 to 3.0 times. When future probable rainfall was the estimated by only observed rainfall, estimated probable rainfall was overestimated. When future probable rainfall was estimated by the A1B scenario, although it was estimated by similar pattern with observed rainfall data, it frequently does not consider the regional characteristics. Comparing with average increased rate of 24-hours annual maximum rainfall and increased rate of probable rainfall estimated by three methods, optimal method of estimated future probable rainfall would be selected for considering climate change.
Problem and Improvement in Design of Drainage Pipe for Bridges
Hong, Kee-Jeung ; Oh, Chang-Kook ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 37~42
DOI : 10.9798/KOSHAM.2011.11.3.037
Recently, the cause of flood damage has been the local torrential rainfalls rather than a total amount of yearly rainfalls. The domestic design code of drainage pump is being improved by considering the effect of local torrential rainfalls, while there is no consideration on the local torrential rainfalls in the domestic design code of bridge-deck drainage. Compared with the code of Federal Highway Administration in USA, no rational bases are specified in the domestic design code of bridge-deck drainage. This paper proposes the reasonable design guideline for bridge-deck drainage considering the effect of local torrential rainfalls.
An Establishment of Database for Effective Design of Anti-Frost Heave Layer using Field Data
Kim, Nak-Seok ; Nam, Young-Kug ; Cho, Gyu-Tae ; Lee, Bum-Woo ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 43~47
DOI : 10.9798/KOSHAM.2011.11.3.043
Korea has seasonal weathers which result in the frosting of soil in winter times, and the thawing of soil in spring. These climate characteristics result in the damaging of pavements, due to the repeated freezing and thawing of road pavements during winter and spring. In order to reduce these pavement damages, anti-frost heave layers are being specially installed, however it is being applied based on foreign researches, and therefore result in the waste of national budget. With this study, a database system was constructed for effective management and monitoring of measured temperatures and function data of 2 meters below the embankment, cut slope, and the cutting-embankment boundary, which are 15 regions picked by the frost index diagram. As the study result, an effective storage and management-purpose database was established for easy data searching and downloading for the pavement design engineers.
An Algorithm for Searching Pareto Optimal Paths of HAZMAT Transportation: Efficient Vector Labeling Approach
Park, Dong-Joo ; Chung, Sung-Bong ; Oh, Jeong-Taek ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 49~56
DOI : 10.9798/KOSHAM.2011.11.3.049
This paper deals with a methodology for searching optimal route of hazard material (hazmat) vehicles. When we make a decision of hazmat optimal paths, there is a conflict between the public aspect which wants to minimize risk and the private aspect which has a goal of minimizing travel time. This paper presents Efficient Vector Labeling algorithm as a methodology for searching optimal path of hazmat transportation, which is intrinsically one of the multi-criteria decision making problems. The output of the presented algorithm is a set of Pareto optimal paths considering both risk and travel time at a time. Also, the proposed algorithm is able to identify non-dominated paths which are significantly different from each other in terms of links used. The proposed Efficient Vector Labeling algorithm are applied to test bed network and compared with the existing k-shortest path algorithm. Analysis of result shows that the proposed algorithm is more efficient and advantageous in searching reasonable alternative routes than the existing one.
Advancement and Application of Integrated Damage Investigation System using Stereo Images and IT
Choi, Woo-Jung ; Cho, Jae-Woong ; Shim, Jae-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 57~61
DOI : 10.9798/KOSHAM.2011.11.3.057
Large scale natural disasters such as floods and typhoons due to climate change have recently occurred with severe damage in all over the world. Especially, current disaster investigation in affected area takes too much time because it can be done by handcrafted. Also, it is lack of somewhat accuracy and objectiveness because it is influenced by investigator's judgment. Further, the current disaster investigation is difficult when damage area is very wide or investigator can't reach the affected area. Hence, we developed the integrated damage investigation system using stereo images and information technology for quick, accurate and objective investigation. Also, we applied the system to Bonghwa-gun in Gyeongsangbuk-do in 2008, Jecheon-si in Chungcheongbuk-do in 2009, and Namwon-si in Jeollabuk-do and Hapcheon-gun in Gyeongsangnam-do in 2010. This paper presents advancement and application of integrated damage investigation system using stereo images and information technology considering mobility, stability and user convenience in field.
A Study on Curriculum Development for Disaster Management by DACUM Technique and Expert Committee
Min, Geum-Young ; Jeong, Duk-Hoon ; Shim, Hyoung-Seop ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 63~73
DOI : 10.9798/KOSHAM.2011.11.3.063
The purpose of this study was to suggest the education and training program for disaster management by comparison between DACUM technique applied curriculum and curriculum by expert committee, and curriculum development. First, DACUM technique applied curriculum development. Job Classification of Disaster management was consisted of four jobs - mitigation, preparedness, response and recovery - by three times discussions of expert panels. Job analysis and curriculum development were performed by the DACUM panels who consisted of three subject-matter experts and one educational expert on each field. Curriculum developed mitigation was nine courses, preparedness was twelve courses, response was seven courses, and recovery was four courses. Second, Expert committee developed curriculum. Expert committee consisted of five experts and three educational expert. Expert committee was held four times. Curriculum developed thirty five courses. Then disaster management curriculum determined by discussion of experts. disaster management curriculum considered (1)mitigation and preparedness was thirty one courses, (2)response and recovery was fourteen courses, (3)man-made was six courses, (4)manager level was four courses.
Age Differences in Safety Perception: A Comparison of Babyboomer, Pre-elderly, and the Elderly
Chung, Soon-Dool ; Oh, Eun-Chan ; Kim, Go-Eun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 75~81
DOI : 10.9798/KOSHAM.2011.11.3.075
The purpose of this study is to observe the age differences in safety perception among babyboomer, pre-elderly, and the elderly and to seek for countermeasures to overcome the risk. The data used for this study were from the 2008 Social Survey conducted by Administration on Statistics, Korea. The data were divided into three different age groups such as babyboomer, pre-elderly, and the elderly. Results showed that overall safety level of the society, safety perception of others and oneself, current social safety level compared to 10 years ago, social safety level after 10years, awareness of safety among different social fields, and the rank among the list of factors that lead to social insecurity appeared to differ according to the three different age groups. The awareness of safety for the elderly group was not higher than babyboomer and pre-elderly groups. Age differences in safety perception reflected the times and experiences the same age cohort went through. Countermeasures for security should be developed by considering the characteristics of the generations and different age groups.
Full Scale Testing of the Effect of Stairwell Pressurization on Pressure Differential and Flow Velocity
Son, Bong-Sae ; Park, Kyung-Hwan ; Chang, Young-Bae ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 83~89
DOI : 10.9798/KOSHAM.2011.11.3.083
A series of full-scale testing was conducted to examine the effect of stairwell pressurization on the pressure differential between the stairwell and the auxiliary room and between the auxiliary room and the residence. Also, flow velocity profiles at open doors were measured. The building tested was a condominium that had twenty floors above the ground and two floors underground. For pressurization of the stairs, a blower was used to supply air into the stairwell at one location underground. Thirteen different cases were tested, and test variables included the number of floors with open doors and the flow rate of the air supply. When the doors on the first floor were open, the pressure differential between the stairwell and the auxiliary room was distributed almost uniformly except for locations near the first floor. When the flow rate was in the range of 180~270 CMM and the doors of one floor were open, the flow velocity could satisfy the requirement of fire safety standards and the stairwell pressure was positive at all levels. However, the minimum pressure requirement (10 Pa) could not always be satisfied. When doors on two floors were open, the flow velocity requirement could be satisfied by increasing the flow rate, but it was found impractical to satisfy the minimum pressure requirement without causing excessive pressure differential in the area near the blower.
Backfill Materials for Underground Facility with Recycling Materials - Quantification of Design Parameters
Lee, Kwan-Ho ; Kim, Seong-Kyum ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 91~96
DOI : 10.9798/KOSHAM.2011.11.3.091
The design, construction and management of underground facilities as infrastructure of nation should be properly carried out. One of reasons for underground facilitie's failure is a non-proper construction of backfill materials. This is common for circular underground pipes. A non-proper compaction is the cause of settlement and decrease of performance of underground facilities. The use of controlled low strength materials is an alternative to reduce the couple of failure problems. The flowability, self-cementation, and non-compaction are the major advantages to use the controlled low strength materials. In this research, couple of recycled materials, such as in-situ soil, water-treatment sludge, and crumb rubbers, were adopted. The basic properties of each materials were determined according to KS or ASTM. Also, couple of laboratory tests were carried out to get the design parameters for geotechnical and roadway area.
Backfill Materials for Underground Facility with Recycling Materials - Small-Scaled Laboratory Chamber Test and FEM Analysis
Lee, Kwan-Ho ; Lee, Kyung-Jung ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 97~103
DOI : 10.9798/KOSHAM.2011.11.3.097
In this research, a small-scaled laboratory test and FEM analysis have been carried out to evaluate the feasibility of field construction with couple of recycled materials, such as in-situ soil, water-treatment sludge, and crumb rubbers. A static loading, which simulates the real traffic load, was adopted in lab test. The test was carried out, according to simulated field construction stages, such as excavation, bedding materials and pipe installation, placing and curing of controlled low strength materials, and simulated traffic loading. Couple of measuring instruments were adopted. The maximum vertical and horizontal deformations were 0.83% and 1.09%, during placing the CLSM. The measured vertical and horizontal deformations with curing time were 0.603mm and 0.676mm, respectively. The reduction effect of vertical and lateral earth pressure was relatively big. Also, FEM analysis was carried out to get the deformation, earth pressure and strain of PVC with different Controlled Low Strength Materials(CLSM) materials.
Stability Analysis of DCM treated Ground Using Centrifuge Test
Kim, Byoung-Il ; Yoo, Wan-Kyu ; Lee, Seung-Hyun ; Han, Jin-Tae ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 105~110
DOI : 10.9798/KOSHAM.2011.11.3.105
Recently, a deep mixture method as a soil improvement method of marine soft ground, which causes less noise and vibration than other methods, are widely used. In this study, for DCM(Deep Cement Mixing) method, one of the deep mixture method, optimum mixing ratio of clay-cement was suggested using uniaxial compression tests on specimens with various mixing ratio of claycement. In addition, the stability of a caisson on tangent circle-type and wall-type DCM treated ground was evaluated using centrifuge tests. As a result, optimum mixing ratio of clay-cement was 28.5% and the stability of the caisson on DCM treated ground was confirmed. However, the lateral displacement of the caisson on the wall-type DCM treated ground was 7% less and the settlement of that was 39% less than the case of the tangent-circle-type DCM method.
A Theoretical Study on the Analytical Solutions for Laterally Loaded Pile
Lee, Seung-Hyun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 111~116
DOI : 10.9798/KOSHAM.2011.11.3.111
Analytical solutions for laterally loaded piles were derived. Critical pile length which can be considered as the length for behaving as long pile was investigated varying with densities of sandy soils. Lateral behaviors obtained from analytical solution and numerical solution were also investigated. Non-dimensional critical pile lengths obtained from analytical solutions for three types of pile head boundary conditions were 2.3~3.2. By comparing analytical solutions with numerical solutions, distribution of pile deflection and that of moment were similar and it can be seen that pile head deflection obtained by analytical method is conservative. And the values of moments were not too different between analytical solution and numerical solution.
Numerical Analysis of Riverbed Changes at the Downstream of the Ji-Cheon
Choi, Ho ; Rim, Chang-Soo ; Jung, Jae-Wook ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 117~125
DOI : 10.9798/KOSHAM.2011.11.3.117
River bed variation drops storage capacity of dams and reservoirs, and furthermore deteriorates safety of banks and peers. Therefore, understanding of bed variation is important to use and manage river water. Study section is downstream part of Ji- Cheon nearby Ji-Cheon Bridge which is located in Gum river basin. The river surveying at fourteen places with the length of 1,320m were undertaken on November 7, 2003 and September 24, 2004, and the results of river surveying were analyzed for the study. Real bed variation was compared with the simulation results of HEC-6 and GSTARS 3.0. Cross section data for the simulation of HEC-6 and GSTARS3.0 were composed of the basis of river surveying data on November 7, 2003. Hydrological data were acquired from Gu-Ryong watermark located at Ji-Chun Bridge. The research results revealed that when using Toffaleti equation, simulation results of two models were similar to the real bed variation. The bed variation simulated by using GSRARS 3.0 with only one stream tube was similar to the real bed variation. The bed variation simulated by using two models(HEC-6 and GSTRARS 3.0) with Toffaleti equation was also similar to the real bed variation. Therefore, it is expected that HEC-6 and GSTARS 3.0 models have applicability to predict the bed variation at the downstream of Ji-Cheon.
Sediments Yield Estimation of Gangwon Mountain Region in Korea
Kwon, Hyuk-Jae ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 127~132
DOI : 10.9798/KOSHAM.2011.11.3.127
In this study, calculation results of sediments yield prediction models were compared with the amount of dredging data for the Inje, Gangwon mountain region of Korea. MSDPM and LADMP were used as a sediments prediction model which was calibrated and modified to calculate the sediments yield of Korean mountain region. Both sediments yield prediction models were modified by using Threshold Maximum Rainfall Intensity and Total Minimum Rainfall Intensity and correction coefficient. After comparing with the amount of dredging, it was found that results of MSDPM is more accurate than the results of LADMP. Difference of results of MSDPM and the amount of dredging is 27.6% and difference of results of LADMP and the amount of dredging is 50.6%. Both sediments yield prediction models which were calibrated in this study can be used to calculate the sediments yield for the Korean mountain region.
An Application of Infiltration Facilities for Reducing the Runoff in the Basin
Lee, Jae-Joon ; Seol, Ji-Su ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 133~141
DOI : 10.9798/KOSHAM.2011.11.3.133
Urban development of basin causes increasing runoff volume and peak flowrate and shortening in time of concentration, which may cause frequent flooding downstream. An infiltration facilities are operated as a method of reducing flood discharge of urban rivers and peak flowrate. There are various types of infiltration facilities like infiltration trench and porous pavement. In this study, runoff reduction effect due to installation of infiltration facilities are performed and focused on
residential area of Ok-kye dong and
industrial area of Gong-dan dong in Gumi City. The analysis is fulfilled with comparison of total runoff volume and runoff reduction volume by using the WinSLAMM and the relation equation between area ratio of infiltration facilities and ratio of runoff reduction are derived and peak flow reduction effect for installation of infiltration facilities is analyzed.
Estimation of Head Loss Coefficients at Surcharged Square Manhole Using Numerical Model
Kim, Jung-Soo ; Lim, Ga-Hui ; Rim, Chang-Soo ; Yoon, Sei-Eui ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 143~150
DOI : 10.9798/KOSHAM.2011.11.3.143
Energy loss at manholes, often exceeding friction loss of pipes under surcharged flow, is considered as one of the major causes of inundation in urban area. Therefore, it is important to analyze the head losses at manholes, especially in case of surcharged flow. The stream characteristics were analyzed and head loss coefficients were estimated by using the computational fluid dynamics(CFD) model, FLUENT 6.3, at surcharged square manhole in this study. The CFD model was carefully assessed by comparing simulated results with the experimental ones. The study results indicate that there was good agreement between simulation model and experiment. The CFD model was proved to be capable of estimating the head loss coefficients at surcharged manholes. The head loss coefficients with variation of the ratio of manhole width(B) to inflow pipe diameter(d) and variation of the drop height at surcharged square manhole with a straight-path through were calculated using FLUENT 6.3. As the ratio of B/d increases, head loss coefficient increases. The depth and head loss coefficient at manhole were gradually increased when the drop height was more than 5cm. Therefore, the CFD model(Fluent 6.3) might be used as a tool to simulate the water depth, energy losses, and velocity distribution at surcharged square manhole.
Flash Flood Risk Assessment using PROMETHEE and Entropy Method
Lee, Jung-Ho ; Jun, Hwan-Don ; Park, Moo-Jong ; Jung, Jae-Hak ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 151~156
DOI : 10.9798/KOSHAM.2011.11.3.151
Previously most of flood prevention efforts have been made for relatively large watersheds near to channel flow. However, as economical development and the expansion of leisure areas to mountainous region, human casualty by flash flood occurs frequently, requiring additional prevention activity. Therefore, to reduce the damage of human lives and property by flash flood, we develop an assessment method for flash flood occurrence for mountainous areas considering various factors involving it. PROMETHEE(Preference Ranking Organization METHod for Enrichment Evaluations) which is one of the MCDM(Multi-Criteria Decision Making) was adopted to assess the contribution of each factor to the risk of the flash flood in the mountainous area. The main evaluation criteria are classified into three categories, namely, the regional and rainfall characteristics, and geographical features. Also, the Entropy method is used to determine the weight of each evaluation criteria without survey. The suggested method based on PROMETHEE with Entropy method is applied to BongHwa region to verify its applicability. After applied, the method successfully assesses the relative risk of flash flood occurrence of each sub region in the BongHwa region. Out of the seventeen sub-regions, five, seven and five of them are evaluated as high-risk, medium-risk, and low-risk, respectively. To verify the results, we searched the historical data of flash flood and the flash flood had occurred in one of high-risk sub-regions at 2008.
Calculation of Direct Runoff Hydrograph considering Hydrodynamic Characteristics of a Basin
Choi, Yun-Ho ; Choi, Yong-Joon ; Kim, Joo-Cheol ; Jung, Kwan-Sue ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 157~163
DOI : 10.9798/KOSHAM.2011.11.3.157
In this study, after the target basin was divided into both overland and channel grids, the travel time from center of each grid cell to watershed's outlet was calculated based on the manning equation. Through this process, volumetric discharge was calculated according to the isochrones and finally, the direct runoff hydrograph was estimated considering watershed's hydrodynamic characteristics. Sanseong subwatershed located in main stream of Bocheong basin was selected as a target basin. The model parameters are only two: area threshold and channel velocity correction factor; the optimized values were estimated at 3,800 and 3.3, respectively. The developed model based on the tuned parameters led to well-matching results between observed and calculated hydrographs (mean of absolute error of peak discharge: 3.41%, mean of absolute error of peak time: 0.67 hr). Moreover, the analysis results regarding histogram of travel time-contribution area demonstrates that the proposed model characterizes relatively well hydrodynamic characteristics of the catchment due to effective rainfall.
Development of River-Reservoir Integrated Model for Flood Reduction Capacity Analysis of Off-Stream Reservoir
Choi, Sung-Yeul ; Ahn, Tae-Jin ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 165~174
DOI : 10.9798/KOSHAM.2011.11.3.165
The purpose of this research is to develop the model for analyzing the hydraulic behavior of off-stream reservoir whose purpose is to reduce a peak flood. When a flood occurs in river, off-stream reservoir has a capability of sharing a part of peak flood. It is accomplished by flowing over a off-line weir that is built by lowering a portion of bank and connecting river with off-line reservoir. Since flood control depends on river elevation, characteristics of off-line weir (elevation, length, position et al.) and reservoir capacities, an integrated model linking the one dimensional unsteady river flow model, off-line weir model and two dimensional unsteady flood model is developed to analyze the behavior of off-stream reservoir and off-line weir. The results show that a flood control capability of off-stream reservoir strongly depends on facilities of off-line weir and storage capacity of offstream reservoir.
Comparative Study on Rainfall Characteristic at World Cities for Evaluation of Flood Risk
Park, Min-Kyu ; Park, Moo-Jong ; Shin, Sang-Young ; Yoo, Chul-Sang ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 175~182
DOI : 10.9798/KOSHAM.2011.11.3.175
The desire for living without hazardous damages grows these days, the city strategy to make the safer community has become an issue. The global assessment for the flood index require the process considering different climate of the world cities. In this study, the actual rainfall observations of the world's major cities were collected. To compare different rainfall characteristics, we calculated some indicators such as frequency factor etc using the probable maximum precipitation. Using the results of these indicators, major cities in Korea show greater variability in the rainfall characteristics when compared to other major cities in the world. These results are expected to be useful for the development of global flood risk assessment as well as the setting the direction for future flood prevention measures.
The Analysis of Sediment Reduction Effect by Installing Check Dams at Domestic Multi-Purpose Dams
Choi, Gye-Woon ; Kim, Kwang-Nam ; Han, Man-Shin ; Yun, Yong-Jin ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 183~189
DOI : 10.9798/KOSHAM.2011.11.3.183
In this study sediments reduction effects on dam have been analyzed in the case of check dam installation in the upstream. Analyzed sediment reduction effects of 27 points conducted for 10 multi-purposes dam, which is target of this study. According to regression analysis result, Sediment reduction effect by installing check dam has shown inclination which increase as area ratio rises. According to analysis result, sediment reduction effect was greatest in Geum-river point at Daecheong-dam. The life-time is estimated to increases about 60% by installing check dams. When Area ratio increases, it was deduced through regression analysis that rise Sediment Reduction Effect by installing check dam. This study can be useful for the management and design plans like the dam's site or priority for placing. Furthermore, it would be able to construct an efficient sand depositing dam if complementary is provided by being considered catchment area and lucrative property.
A Study of Flow Characteristics in Meandering River
Son, Ah-Long ; Ryu, Jong-Hyun ; Han, Kun-Yeun ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 191~200
DOI : 10.9798/KOSHAM.2011.11.3.191
Levee failure cause the huge amount of damage to human and property. Overflow and erosion of levee are primary cause of a break in a levee but the analysis of breach pattern and impact is partially inadequate. The flow characteristics of meandering rivers are very important in field of river hydraulics that should be studied in practical viewpoints relating to river levee. In meandering the secondary flow that rotary direction is changed reciprocally occurs in three dimension is known. In this study flow characteristics of local river are considered and of meandering channels are analyzed using CCHE2D and FLOW3D. The stability and accuracy of models are examined comparing the measuring and analyzed data for the experimental channel and natural river(Namgang). Consequently, the flow characteristics in a meandering river are suggested precisely and it is essential that river levees having meandering river should be analyzed.
Assessment of the Planned Bank Revetment Using Analytic Hierarchy Process
Jeong, Jang-Myeon ; Kim, Chul ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 201~208
DOI : 10.9798/KOSHAM.2011.11.3.201
When designing a river, it is important to select the appropriate bank revetment methods, but there are no specific guidelines until now. Accordingly, it is important to prevent over-budgeting by deciding the suitability of the adopted bank revetment methods when designing a river. In this study, an assessment method was developed to assess the suitability of the adopted bank revetment methods when designing a river. By adopting this method to eight rivers, its validity was examined. Analytic Hierarchy Process (AHP) was used for the assessment, along with suitability index (SI) of the adopted bank revetment methods when designing a river. In order to select the best bank revetment methods, all environmental variables of the selected location have to be considered. Accordingly, to assess the designed bank revetment methods, all variables of the selected location have to be considered. The assessing items include hydraulic stability, environmental-ecological feasibility, economy, and amenity of the bank revetment. Each item includes four to five sub-items, and each sub-items reflect survey results on the locations. The assessment method was adopted and assessed for eight rivers, and bank revetments was designed to determine the SI. The result of this study is considered to be appropriate when assessing an eco-friendly bank revetment methods, and inappropriate designed bank revetments will guide future planners for selecting the most appropriate construction method.
Design Methodology on the Steel-type Breakwater I.Design Procedure and Wave Pressure Estimation
Kweon, Hyuck-Min ; Han, Yu-Shik ; Kwon, Oh-Kyun ; Ko, Kyoung-Lae ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 209~218
DOI : 10.9798/KOSHAM.2011.11.3.209
The present study proposes a new estimation relationship for the transmission rate of the steel breakwater which is expected to make up for the weakness points in existing hard solution for shore protection. The steel breakwater consists of the wave dissipator of the dual horizontal plates, the supporting columns and their foundations, and thus its respective designs should also be conducted one by one. Furthermore, the breakwater has to ensure both functions of shore protection and structure stabilization. The study produced experimental data for the stability and safety investigation of the steel breakwater. The forces acting on the steel breakwater were classified into two categories, one is vertical up and down loads for the pile resistance and the other was maximum difference of the vertical load acting on horizontally different position for the torsion. The study applied the stability force produced by the summation of maximum pressure at each point and the safety force acting on each point simultaneously. The regular wave corresponding to the significant wave was utilized for measuring wave pressure and force. The study showed the method for the proper position of submerged upper plate by considering occurrence frequency of tide level. The design process finally determined by trial and error is proposed in the present study.
Design Methodology on Steel-type Breakwater II. Pile Design Procedure
Kwon, Oh-Kyun ; Oh, Se-Boong ; Kweon, Hyuck-Min ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 219~228
DOI : 10.9798/KOSHAM.2011.11.3.219
In this paper, the design procedure of substructure of the steel-type breakwater was described and the actual foundation design was performed for the test bed. The site investigation was executed at the Osan-port area, in Uljin, Gyeongbuk, where the steeltype detached breakwater is constructed. The foundation mainly depends on the lateral load and uplift force due to the wave force. Since the superstructure is stuck out about 9.0m from the ocean bed, the foundation must resist on the lateral force and bending moment. After considering various factors, the foundation type of this structure was determined by the steel pipe pile(
). On the stability of pile foundation, the safety factors of the pile on the compressive, lateral and uplift forces were grater than the minimum factor of safety. The displacements of pile under the working load were evaluated as the values below the permissible ones. Based on the subgrade reaction method, we evaluated the relationship of subgrade reaction and displacement for the lateral and the vertical directions in the layers. The structural analyses along with the foundation were perfomed and the effect of pile foundations were compared quantitatively.
Method to Determinate Monitoring Points in Sewer Networks
Lee, Jung-Ho ; Jun, Hwan-Don ; Park, Moo-Jong ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 229~235
DOI : 10.9798/KOSHAM.2011.11.3.229
In order to manage a sewer system effectively, flow conditions such as flux, water quality, Infiltration and Inflow (I/I), Combined Sewer Overflows (CSOs), etc need to be monitored on a regular base. Therefore, in sewer networks, a monitoring is so important to prevent the river disaster. Monitoring all nodes of an entire sewer system is not necessary and cost-prohibitive. Water quality monitoring points that can represent a sewer system should be selected in a economical manner. There is no a standard for the selection of monitoring points and the quantitative analysis of the observed data has not been applied in sewer system. In this study, the entropy method was applied for a sewer network to evaluate and determine the optimal water quality monitoring points using genetic algorithm. The entropy method allows to analyze the observed data for the pattern and magnitude of temporal water quality change. Since water quality measurement usually accompanies with flow measurement, a set of installation locations of flowmeters was chosen as decision variables in this study.
Nitritation at Various Temperature Conditions - Using Anaerobic Digester Supernatant
Gil, Kyung-Ik ; Im, Ji-Yeol ;
Journal of Korean Society of Hazard Mitigation, volume 11, issue 3, 2011, Pages 237~243
DOI : 10.9798/KOSHAM.2011.11.3.237
As the effluent quality standard of the municipal wastewater treatment plant (MWTP) has been strengthened, the treatment of the recycle water containing high concentration of ammonium nitrogen has been considered as one of retrofit methods for upgrading the exising MWTPs. In this study, nitritation, economic nitrogen removal process, was induced by laboratory-scale reactor at the
temperature conditions using anaerobic digester supernatant. The stable nitritation was achieved over
, but nitrification was induced at
. It means that the nitritation was affected by SRT and temperature. SRT, demanded for nitritation, is changed according to the temperature. Therefore, it is considered that SRT and temperature are important factors in nitritation. Also, it is approved that inducing the ammonium nitrogen removal and the nitritation are more beneficial over
. The conclusion of this study can be used for the important basic reference when nitritation process is applied for MWTPs.