• Title/Summary/Keyword: Drainage method

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Risk assessment for inland flooding in a small urban catchment : Focusing on the temporal distribution of rainfall and dual drainage model (도시 소유역 내 내수침수 위험도 평가 : 강우 시간분포 및 이중배수체계 모형을 중심으로)

  • Lee, Jaehyun;Park, Kihong;Jun, Changhyun;Oh, Jeill
    • Journal of Korean Society of Water and Wastewater
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    • v.35 no.6
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    • pp.389-403
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    • 2021
  • In this study, dual drainage system based runoff model was established for W-drainage area in G-si, and considering the various rainfall characteristics determined using Huff and Mononobe methods, the degree of flooding in the target area was analyzed and the risk was compared and analyzed through the risk matrix method. As a result, the Monobe method compared to the Huff method was analyzed to be suitable analysis for flooding of recent heavy rain, and the validity of the dynamic risk assessment considering the weight of the occurrence probability as the return period was verified through the risk matrix-based analysis. However, since the definition and estimating criteria of the flood risk matrix proposed in this study are based on the return period for extreme rainfall and the depth of flooding according to the results of applying the dual drainage model, there is a limitation in that it is difficult to consider the main factors which are direct impact on inland flooding such as city maintenance and life protection functions. In the future, if various factors affecting inland flood damage are reflected in addition to the amount of flood damage, the flood risk matrix concept proposed in this study can be used as basic information for preparation and prevention of inland flooding, as well as it is judged that it can be considered as a major evaluation item in the selection of the priority management area for sewage maintenance for countermeasures against inland flooding.

Affecting Discharge of Flood Water in Paddy Field from Selecting Rainfall with Fixed and Unfixed Duration (고정, 임의시간 강우량 선택에 따른 농경지 배수 영향 분석)

  • Hwang, Dong Joo;Kim, Byoung Gyu;Shim, Jwa Keun
    • KCID journal
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    • v.19 no.1
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    • pp.64-76
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    • 2012
  • Recently, it has been increased disaster of crops and agricultural facilities with climate change such as regional storm, typhoon. However agricultural facilities have unsafe design criteria of improving drainage corresponding to this change. This study has analyzed the impact that inundation area and magnitude of drainage-facility is decided based on fixed- and unfixed-duration precipitation by applying revised design criteria of drainage for climate change. The result was shown that 1-day and 2-days rainfall for 20-years return period has increased about 11.4%, 4.4% respectively by changing fixed- to unfixed duration. And the increase rate of design flood was 15.0%. The result was also shown that Inundation area was enlarged by 6.6% as well as increased inundation duration under same basic condition in designed rainfall between fixed- and unfixed-duration. According to the analysis, it is necessary for pump capacity in unfixed-duration to be increased by 70% for same effect with fixed-duration. Therefore, when computing method of probability precipitation is changed from fixed one to unfixed-duration by applying revised design criteria, there seems to be improving effect in drainage design. Because 1440-minutes rainfall for 20-years return period with unfixed-duration is more effective than 1-day rainfall for 30-years return period with fixed-duration. By applying unfixed-duration rainfall, capacity of drainage facilities need to be expanded to achieve the same effects (Inundation depth & duration) with fixed-duration rainfall. Further study is required for considering each condition of climate, topography and drainage by applying revised design criteria.

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Percutaneous Drainage of Lung Abscess and Infected Bulla (폐농양과 감염성 낭포의 경피적 배농술)

  • Kim, Gun-Ho;Hwang, Young-Sil;Kim, Hyung-Jin
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.2
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    • pp.120-126
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    • 1994
  • Background : Antibiotic therapy has proven an effective method of treatment on the majority of patients with pyogenic lung abscess and infected bulla. When medical therapy has failed, pulmonary resection is the current generally recommended therapy. But nowdays complications of percutaneous tube drainage has decreased with the use of small catheter. So we evaluated the effect of percutaneous tube drainage as an alternative therapy to the pyogenic lung abscess and infected bulla refractory to medical therapy in preference ot the pulmonary resection. Method : Nine cases of the lung abscess and three cases of infected bulla which has large cavity size over 6cm, and has underlying diseases such as lung cancer, diabetes mellitus, refractory to over 1 week of antibiotics, were performed percutaneous tube drainage with All Purpose Drainage catheter(Medi-tech, Watertown, USA) under fluoroscopy. Results : All the cases except one case which complicated empyema was improved clinically. Fever was down within 4days of percutaneous tube drainage(mean : 1.9days). Mean duration of tube drainage was 9.9days. Conclusion : Percutaneous tube drainage is an effective and relatively safe procedure in the management of lung abscesses that do not response to medical therapy. We speculate this procedure should be considered as an alternative therapy for the lung abscess refractory to medical therapy in preference to the surgery. The safety and effectiveness of this procedure in infected bulla should be evaluated with an additional study.

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Optimal Location of Best Management Practices for Storm Water Runoff Reduction (우수유출저감 시설의 최적위치 결정)

  • Jang, Su Hyung;Lee, Jiho;Yoo, Chulsang;Han, Suhee;Kim, Sangdan
    • Journal of Korean Society on Water Environment
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    • v.24 no.2
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    • pp.180-184
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    • 2008
  • A distributed hydrologic model of an urban drainage area on Bugok drainage area in Oncheon stream was developed and combined with a optimization method to determine the optimal location and number of best management practices (BMPs) for storm water runoff reduction. This model is based on the SCS-CN method and integrated with a distributed hydrologic network model of the drainage area using system of 4,211 hydrologic response units (HRUs). Optimal location is found by locating HRU combination that leads to a maximum reduction in peak flow at the drainage outlet in this model. The results of this study indicate the optimal locations and numbers of BMPs, however, for more exact application of this model, project cost and SCS-CN reduction rate of structural facilities such infiltration trench and pervious pavement will have to be considered.

Tracer Experiment and Computational Fluid Dynamics Analysis for the Drainage Efficiency of a Reservoir (배수지의 배수효율분석을 위한 추적자실험 및 전산유체해석)

  • Cho, Jung-Yeon;Go, Sun-Ho;Kwac, Lee-Ku
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.2
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    • pp.22-27
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    • 2017
  • During the water treatment process for household water supply, a reservoir is the last place the water is stored before being supplied to users, and the duration of the water's stay is an important factor that affects its safety. This may cause the concentration of the residual chlorine disinfectant to increase and thus lower the water's quality. The concentration and discharge efficiency of residual chlorine must be verified and managed, because these are key factors that affect the reservoir's performance. Because the actual verification test for analyzing the efficiency of a reservoir and the disinfectant's dilution capacity is difficult, simulations are generally conducted using the computational fluid analysis method. However, the simulation results require validation with experiments. The error and drainage efficiency were analyzed in this study by comparing and analyzing the actual tracer test and simulation so that the actual test for a hexagonal drainage can be replaced by the computational fluid analysis method. Based on the results of the efficiency analysis, the hexagonal reservoir was found to be appropriate, and the simulation's reliability was verified with a tracer test.

Drainage with the Seldinger Technique for Cardiac Tamponade (심장압전에 대한 Seldinger 방법을 이용한 심낭배액술 -2례 보고-)

  • Kim, Jong-Won;Park, Seo-Wan;Kim, Byeong-Jun
    • Journal of Chest Surgery
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    • v.29 no.10
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    • pp.1152-1156
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    • 1996
  • Cardiac tamponade Is an acute, life-threatening emergency, requiring immediate decompression by a safe and simple method. The most effective method of drainage has been controversial. We experienced successful outcome for the treatment of cardiac tamponade with drainage using the Seldinger technique. The causes of the cardiac tamponade were hemopericardium after mitral and aortic valve replacement and malignant pericardial effusion due to primary lung cancer. They were treated with emergency rainage by the Seldinger technique without procedure-related complications. We believe that this technique is simple, safe for the treatment of cardiac tamponade.

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A Comparative Study on the Clamping Protocols of a Biliary External Drainage Tube in Adult Living-donor Liver Transplant Recipients (성인 생체 간이식 수혜자에서 담도 외-배액관 잠그기 훈련 방법 비교)

  • Chung, Jin Ah;Choi, Hye Ran
    • Journal of Korean Critical Care Nursing
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    • v.7 no.1
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    • pp.33-39
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    • 2014
  • Purpose: The propose of this study was to introduce the clamping protocols for a biliary external drainage tube and trace the results of using clamping protocols to prevent some possible biliary complications or enable their early detection in living-donor liver transplantation. Method: This study was a retrospective study to analyze the cases of 97 subjects who had undergone liver transplantation in a hospital in Seoul, Korea. Clamping protocol 1 was applied to 47 patients, and clamping protocol 2 was applied to 50 patients. Results: In the case of protocol 1, the success rate of the clamping protocol was 74.5%, while that of protocol 2 was 84.0%. However, there was no significant difference in the compiled statistics from authentic sources (p = .246). Conclusions: The difference in the success rate between the two protocols was not significant for the clamping protocols of the biliary external drainage tube. However protocol 2 is suggested for the clamping method due to the simplicity of application. Further study with a large sample size is suggested.

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A Study of Sedimentation Processes of Saemangeum Reclamation(II) - A Study of Sedimentation Processes after Saemangeum Reclamation - (새만금간척 퇴적과정에 관한 연구(II) -새만금간척 시행 후를 중심으로-)

  • 신문섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.5
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    • pp.33-40
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    • 2002
  • The purpose of this study is to find the variation of sedimentation patterns after Saemangeum reclamation. Residual flow after Saemangeum reclamation was calculated prognostically from the observed water temperature and salinity data in May 1992 by the Marine Development Institute of Gunsan National University and wind data which were obtained from spring 1969 through winter 1977 by the Kunsan Meteorological Observatory. Three dimensional movements of injected particles due to currents, turbulence and sinking velocity are tracked by the Euler-Lagrange method. When suspended sediments with the size of soil grain of 30 ㎛ are injected in the Sinsi drainage sluice, their dispersion range of sediment is around Gogunsan islands. When suspended sediments with the size of soil grain of 200 ㎛ are injected in the Garyeok drainage sluice, their dispersion range of sediment was around the Garyeok drainage sluice and Byeonsan coastal area.

Improvement of existing drainage system for leakage treatment in exiting underground structures (운영중인 지하구조물의 누수처리를 위한 유도배수공법의 개선)

  • Kim, Dong-Gyou;Yim, Min-Jin
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.19 no.4
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    • pp.669-683
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    • 2017
  • The objective of this study is to propose a modification of the previously proposed drainage system for catching the partial leakage of underground concrete structures. Two techniques were proposed for applying the drainage system only to the leaking parts. One was for conveying leaking groundwater to the collection point in the drainage system and the other was for conveying the collected groundwater to the primary drainage system of the underground concrete structure. Four waterproofing materials for conveying leaking groundwater to the catchment point of the drainage system, Durkflex made of porous rubber material, KE-45 silicone adhesive with super strong adhesion, Hotty-gel made of polymeric materials and general silicone adhesive were evaluated for waterproofing performance. Hotty-gel only showed perfect waterproof performance and the other three waterproof materials leaked. The modified drainage system with Hotty-gel and drainage pipe with fixed saddle to convey the leaking groundwater from the catchment point to the primary drainage system were tested on the concrete retaining wall. The waterproof performance and the drainage performance were evaluated by injecting 1,000 ml of water in the back of the modified drainage system at the 7-day, 14-day, 21-day, 28-day, 2-month and 3-month. There was no problem in waterproof performance and drainage performance of the modified drainage system during 3 months. In order to evaluate the construction period and construction cost of the modified drainage system, it was compared with the existing leaching repair method in surface cleaning stage, leakage treatment stage, and protective barrier stage. Total construction period and construction cost were compared in considering the contents of work, repair material, construction equipment, working time, and total number of workers. As a result of comparing and analyzing in each construction stage, it was concluded that the modified drainage system could save construction period and construction cost compared to the existing leaching repair method.