• Title/Summary/Keyword: Check dam

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Safety estimation of check dam in Muju region according to debris yield (토사유출에 따른 무주지역 사방댐의 안전성 평가)

  • Kwon, Hyuk Jae;Kim, Hyeong Gi
    • Journal of Korea Water Resources Association
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    • v.54 no.11
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    • pp.915-924
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    • 2021
  • In this study, the probability of exceeding capacity for 4 check dams in Muju mountain region have been estimated. From the results, optimum design of check dam and safety according to wild fire have been discussed. Reliability model has been established by using MSDPM for calculating debris yield to estimate the probability of exceeding capacity of check dam. Probability of exceeding capacity for 4 check dams has been estimated according to maximum rainfall intensity of return periods (10year, 50year, 100year, and 200year). It was found that 1 check dam of Samga-ri basin and 1 check dam of Jeungsan-ri basin were designed by overestimation and 61% and 47% of capacity should be reduced, respectively. Furthermore, probability of exceeding capacity according to burned area has been estimated and compared. It was found that check dam of Sanga-ri basin is the weakest for the wild fire effect in this study area.

Estimation of Sediment Discharge Controlled by Sediment-filled Check-dam in a Forested Catchment (산림유역의 만사 사방댐에 의한 토사유출 조절 효과 추정)

  • Seo, Jung Il;Chun, Kun Woo;Song, Dong Geun
    • Journal of Korean Society of Forest Science
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    • v.105 no.3
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    • pp.321-329
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    • 2016
  • To estimate the sediment discharge controlled by sediment-filled check-dam and thereby enhancing factor for check-dam design and dredging criteria, we surveyed slope failures and stream-bed fluctuation caused by geomorphic disturbances (i.e., landslides and debris flows) in Inje, Gangwondo. In general, check-dams play roles for restraining and controlling sediment discharge within a section under the design equilibrium gradient and a section under the design flood gradient, respectively. The results in this study showed same pattern: that is, the closed type check-dam, which has a design restraint sediment discharge of $2,111m^3$, estimated to control a sediment discharge of $3,996m^3$ in the stream section within 250 m right upper area immediately after the disturbances occurred in 2006. As a result, a design control sediment discharge of the check-dam was larger than its design restraint sediment discharge. This represents that the check-dam is still having an own function for controlling sediment discharge although it exceeded the designed capacity by the sediment discharged from upstream during the disturbances. Our finding suggests that the sediment discharge controlling of check-dam may need to be evaluated separately from its sediment discharge restraint. Currently, the country, however, does not consider the design control (or restraint) sediment discharges, based on the actual field survey, as criteria for check-dam design and/or dredging work. Therefore, the accumulation of the quantitative data is required to support that check-dam has functions for both restraining and controlling sediment discharge. This would be a way to develop our erosion control technology to the scientific technology equipped with a more objective and systematic aspects.

The Analysis of Sediment Reduction Effect by Installing Check Dams at Domestic Multi-Purpose Dams (국내 다목적 댐의 저사댐 설치에 따른 퇴사저감 효과 분석)

  • Choi, Gye-Woon;Kim, Kwang-Nam;Han, Man-Shin;Yun, Yong-Jin
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.183-189
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    • 2011
  • 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 on the Safety Inspection of Erosion Control Facilities (I): In Case of Check Dams Located in the Gangwon Region (사방시설의 안전점검에 관한 연구(I) - 강원지역의 사방댐 점검결과를 중심으로 -)

  • Lee, Jin-Ho;Chun, Kun-Woo;Lee, Sang-Myung;Park, Ju-Hwan;Kim, Bong-Ki;Kim, Suk-Woo;Seo, Jung Il
    • Journal of Forest and Environmental Science
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    • v.29 no.3
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    • pp.226-236
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    • 2013
  • Recently check dam construction number have been increased by becoming known that effectiveness in the control of the landslide and debris flow. However, check dam management standards are not setting yet. Therefore, this study was carried by provide a basic data for the check dam management and inspection in the Gangwondo. The followings are the results of safety inspection on the 274 check dams, which are located in mountain streams, Gangwondo, Republic of Korea. 1. It was determined that, of 274 check dams inspected, 267 check dams (97.4%) generally had a safe condition but 7 check dams (2.6%) had a bad condition that repair and/or complementary measures are required. 2. The check dams with a bad condition had the ages greater than approximately 20 years. This result should be reflected to future stream management strategy including a timing of the specific inspection for durability of check dams. 3. Our finding suggests that the safety inspection of check dams is able to provide basic information required to maintain their own functions, and thus it should be widely applied to stream management strategy against to sediment-related disasters in the future.

Analysis of the Adequacy Check Dam according to Soil Loss using RUSLE (RUSLE 모형으로 토사유실에 따른 사방댐 적정성 분석)

  • Choi, Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.5
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    • pp.515-524
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    • 2016
  • Damage such as landslides has been caused by natural phenomenon like a heavy rain. As appropriate countermeasures, rather than analysing the cause of the landslide, we used methods of check dam installation and maintenance mountain basin. A check dam is a small, sometimes temporary, dam constructed across a swale, drainage ditch, or waterway to counteract erosion by reducing water flow velocity. In this study, we analysed the adequacy of check dam built to prevent further damage after landslides through GIS and examined the sediment erosion in the existing check dams for an ideal location of check dam, considering the accessibility and size. As a result of reviewing soil loss in the study watershed according to RUSLE(Revised Universal Soil Loss Equation), the basin I had about 2% soil loss reduction, the basin II showed less than 1 % soul loss reduction, and basin III showed the reducing effect of 5 % soil erosion.

New Paradigm on the Safety Check of Concrete Gravity Dams at Earthquake (중력식댐의 지진시 안전검토에 대한 뉴 패러다임)

  • Bae, Jung-Joo;Kim, Yon-Gon;Lee, Jee-Ho
    • Journal of the Korean Society of Safety
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    • v.24 no.6
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    • pp.86-92
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    • 2009
  • In the safety check of gravity dams at earthquake, there have been two types of analysis conducted simultaneously; one is stability analysis and the other stress analysis. But those are essentially the same calculation other than the former considers the dams rigid, while the latter considers the dams' dynamic characteristics which results in the amplification of response acceleration on the upper part of dam body. In this paper, the identity of those two methods is verified by example calculation in terms of stability check of gravity dam. It can be concluded that if stress analysis were performed, stability check of gravity dam could be accomplished with the results from stress analysis, removing unnecessary present dual calculation practice.

A Study on Public Awareness of Landslide and Check Dam Using the Big Data Platform 'Hyean' (공공 빅데이터 플랫폼 '혜안'을 통한 산사태 및 사방댐 인식 분석)

  • Sohee Park;Min Jeng Kang;Song Eu
    • Journal of the Society of Disaster Information
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    • v.18 no.4
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    • pp.687-698
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    • 2022
  • Purpose: This study was conducted to understand the public awareness of landslide and check dams in 2015-2020 using the big data platform 'Hyean' and to confirm the utilization of this platform in disaster prevention areas. Method: The total amount, number of detection by period by media, and affirmative and negative trends of a search for 'landslide' and 'check dam' in 2015-2020 were analyzed using a keyword search of 'Hyean.' Result: There is significant lack of public awareness of check dam compared to landslide, and the trend is more noticeable in the conspicuous gap of data amount between the news and SNS media. The number and the timing of the search for 'landslide' coincided with the actual occurrence of landslide, while the detection of 'check dam' was less related to it. Relatively affirmative preception for the check dam is inferred, but it was difficult to confirm accurate statistical affirmative and negative trends in the disaster prevention field using 'Hyean.' Conclusion: Unlike the experts who expect positive public awareness of check dam, the statistic results show that the public awareness of the check dam as an effective countermeasure against landslide was extremely low. Active promotion of erosion control projects should be carried out first, and a balanced sample survey should accompany online and periodic field surveys. Since there is a limit to grasping the effective perception in the field of disaster prevention area using 'Hyean', it should be very cautious to establish local/governmental policies using it.

Analysis of Debris Flow Disaster Area according to Location Change of Check Dam using Kanako-2D (Kanako-2D를 이용한 사방댐 위치 변화에 따른 토석류 피해지 분석)

  • Kim, Young Hwan;Jun, Kye-Won
    • Journal of the Korean Society of Safety
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    • v.33 no.1
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    • pp.128-134
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    • 2018
  • With the increase in frequency of typhoons and heavy rains following the climate change, the scale of damage from the calamities in the mountainous areas has been growing larger and larger, which is different from the past. For the case of Korea where 64% of land is consisted of the mountainous areas, establishment of the check dams has been drastically increased after 2000 in order to reduce the damages from the debris flow. However, due to the lack of data on scale, location and kind of check dams established for reducing the damages in debris flow, the measures to prevent damages based on experience and subjective basis have to be relied on. Under this study, the high-precision DEM data was structured by using the terrestrial LiDAR in the Jecheon area where the debris flow damage occurred in July 2009. And, from the numerical models of the debris flow, Kanako-2D that is available to reflect the erosion and deposition action was applied to install the erosion control facilities (water channel, check dam) and analyzed the effect of reducing the debris flow shown in the downstream.After installing the erosion control facilities, most of debris flow moves along the water channel to reduce the area to expand the debris flow, and after installing the check dam, the flow depth and flux of the debris flow were reduced along with the erosion. However, as a result of analyzing the diffusion area, flow depth, erosion and deposition volume of the debris flow generated from the deposition part after modifying the location of the check dams with the damages occurring on private residences and agricultural land located on the upstream area, the highest reduction effect was shown when the check dam is installed in the maximal discharge points.

IMPROVING HABITAT OF FORMOSAN LANDLOCKED SALMON BY DAM REMOVAL

  • Yeh, Chao-Hsien;Lien, Hui-Pang
    • Water Engineering Research
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    • v.6 no.4
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    • pp.149-159
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    • 2005
  • With increasing recognition on conservation of endangered species in Taiwan, one of the major conservation projects is the habitat restoration of Formosan Landlocked Salmon which is major threatened by check dams in the channel for their blockading pathway to upstream and causing the problems of population isolation and close-blood mating. By creating an opening in the central dam body appropriately, partial removal dams can provide pathway for the fish for the better upstream channel habitat. Four check dams at Gau-Shan Creek were remodeled between April of 1999 and September of 2002 with information supported from model experiments under certain hydraulic condition of field environment. Based on the follow-up investigation, the channel morphology of observation sections is in stable condition and the total number of Formosan Landlocked Salmon in this creek increased promptly at the reach containing partial-removed dams.

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Development on Prediction Algorithm of Sediment Discharge by Debris Flow for Decision of Location and Scale of the Check Dam (사방댐 위치 및 규모 결정을 위한 토석류 토사유출량 예측 알고리즘 개발)

  • Kim, Kidae;Woo, Choongshik;Lee, Changwoo;Seo, Junpyo;Kang, Minjeng
    • Journal of the Society of Disaster Information
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    • v.16 no.3
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    • pp.586-593
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    • 2020
  • Purpose: This study aims to develop an algorithm for predicting sediment discharge by debris flow, and develop GIS-based decision support system for optimal arrangement of check dam. Method: The average stream width and flow length were used to predict the cumulative sediment discharge by debris flow. At this time, the amount of slope failure on source area and average flow length were utilized as input factors. Result: The predicted sediment discharge calculated through the algorithm was 1.1 times different on average compared to the actual sediment discharge by debris flow. In addition, the program is an objective indicator that selects the location and size of the check dam, and it can help practitioners make rational decisions. Conclusion: The soil erosion control works are being implemented every year. Therefore, it is expected that the GIS-based decision support system for location and size of the check dam will contribute to the prevention of sediment-related disasters.