• Journal of Korea Water Resources Association
• /
• v.49 no.5
• /
• pp.381-389
• /
• 2016

In this study, we developed evaluation indicators of dam rehabilitation considering climate change in order to prepare for safety of aging dam facilities in accordance with changes in rainfall intensity. The validity and appropriateness of each indicator, and the evaluation criteria were selected for quantitative indicators for each detail through domestic and international case studies, literature review, and expert advice. The survey was carried out to estimate the importance of each indicator for dam rehabilitation. The subjective assessment of the respondents was rearranged using pairwise comparison from the Analytic Hierarchy Process (AHP). The reliability of the survey results was evaluated through consistent verification. In addition, a comparative assessment was carried out which evaluated the reliability importance estimation result to refine the criteria to distinguish rating scales between expert and non-expert groups on dam-related fields.

• Journal of Korea Water Resources Association
• /
• v.38 no.2
• /
• pp.97-110
• /
• 2005

This paper presents a procedure of evaluation of reservoir capacity for additional water storage for dam rehabilitation. One of the techniques on the extension of rainfall has been developed, and the daily stream flows were simulated by the NWS-PC long-term rainfall-runoff model with the input of the extended daily rainfall which was stochastically generated by the nonhomogeneous markov chain model. We peformed a reliability analysis to Guisan dam about the optimal capacity of dam rehabilitation by using performance criteria that Hashimoto et al. (1982) presented. We estimated that the most suitable water level is approximately 155EL.M. suggested that this method can use supplemental methods to estimate optimum dam scale.

• Smart Structures and Systems
• /
• v.26 no.3
• /
• pp.319-329
• /
• 2020

Structural damage to an arch dam is often of major concern and must be evaluated for probable rehabilitation to ensure safe, regular, normal operation. This evaluation is crucial to prevent any catastrophic or failure consequences for the life time of the dam. If specific major damage such as a large crack occurs to the dam body, the assessments will be necessary to determine the current level of safety and predict the resistance of the structure to various future loading such as earthquakes, etc. This study investigates the behavior of an arch dam cracked due to water pressure. Safety factors (SFs), of shear and compressive tractions were calculated at the surfaces of the contraction joints and the cracks. The results indicated that for cracking with an extension depth of half the thickness of the dam body, for both cases of penetration and non-penetration of water load into the cracks, SFs only slightly reduces. However, in case of increasing the depth of crack extension into the entire thickness of the dam body, the friction angle of the cracked surface is crucial; however, if it reduces, the normal loading SFs of stresses and joints tractions reduce significantly.

• Journal of Korea Water Resources Association
• /
• v.30 no.6
• /
• pp.679-690
• /
• 1997

The risk assessment model for hydrlolgic safety analysis of dam and levee in developed by using Monte-Carlo and AFOSM (Advanced First-Order Second-Moment) method. The fault tree analysis and four phases approach are presented for the safety eveluation of risk of dam and levee. The risk model consists of rainfall-runoff analysis, reservoir routing and channel routing considering the variations in the model parameter. For the rainfall-runoff analysis, KRRL method is adopted with 200-year precipitation and PMP (Probable Maximum Precipitation). Reservoir routing is performed by fourth order Runge-Kutta method and channel routing by standard step method. The suggested model will contribute to safety evaluation of dam and levee and their rehabilitation decision problem.

• Journal of Korea Water Resources Association
• /
• v.39 no.12 s.173
• /
• pp.1067-1080
• /
• 2006

In empirical evaluations of public projects and public provided goods, MCDA(multicriteria decision-making analysis) has helped decision makers with an adequate policy decision-making tool since it allows taking into account a wide range of assessment criteria. As a tool for decision-making of conflict management, MCDA has demonstrated its usefulness in many public projects such as road, dam and harbor construction. In this study, to use this merit of MCDA, dam project assessment indicators from points of social, economic, environmental and practical views are developed based on sustainable development of water resources, and weighting factors are also estimated by means of questionnaire survey. In order to decide project investment rank, developed evaluation indicators are applied to 6 existing dams under investigation for a rehabilitation project. In addition to, it is recognized that the project practicability has become more important indicator as well as environmental and social issues. This is because cooperation and support from a local government and people are regarded as one of the most important problems in public projects recently.

• Journal of the Korean Geosynthetics Society
• /
• v.11 no.3
• /
• pp.53-58
• /
• 2012

There are about 17,531 agricultural small dams and reservoirs in Korea. Ninety five percent of the small dams were constructed by earthfill and they were suffered severe damages or expected to repairs or rehabilitation. Therefore dams are evaluated and are identified their problems. Small Dams should be repaired before too late. Small dam safety evaluation is required to guarantee the proper functions of the existing agricultural dams and reservoirs in time and to minimize the damage.

• Korean Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.242-254
• /
• 2010

Streams changed by artificial factor those support positive functions but also negative function to humanbeing. Time and pathway exceed the lost of structure and negative function appearing as disturbance. Therefore, it is desirable to prepare right situation to break of a vicious circle. Stream ecology was evaluated with using ichthyofauna during three years at the three disturbed sites and reference sites in Nakdong River. Forty-one species belonging three orders and ten families were identified in six surveying sites of Nakdong River during 2007~2009. Korean endemic species (14 species, 34.1%) and alien (3 species, 7.3%) were identified in Nakdong River ichthyofauna. Species number, species diversity, ecosystem structure and habitat variability of ecosystem were applied to evaluate stream ecosystem. In view of three year comprehended data at six sites; numeric instability appeared Andong Dam and Naeseongcheon sites worse than Gamcheon and reference site, otherwise more numeric diversity appeared Gamcheon and reference site than Andong Dam and Naeseongcheon. As a result of integration, sand stream including downstream of Andong dam, Naeseongcheon and Gamcheon has been having more diversified biodiversity and habitat diversity than those in the pebble stream.

• Korean Journal of Hydrosciences
• /
• v.8
• /
• pp.31-40
• /
• 1997

Flow carrying capacity of water distribution systems is getting reduced by deterioration of pipes in the systems. The objective of this paper is to present a managerial decision-making model for the rehabilitation of water distribution systems with a mininum cost. The decisions made by the model also satisfy the requirements for discharge and pressure at demanding nodes in the systems. Replacement cost, pipe break repair cost, and pumping cost are considered in the economic evaluation of the decision along with the break rate and the interest rate to determine the optimal replacement time for each pipe. Then, the hydraulic integrity of the water distribution system is checked for the decision by a pipe network simulator, KYPIPE, if discharge and pressure requirements are satisfied. In case the system does not satisfy the hydraulic requirements, the decision made for the optimal replacement time is revised until the requirments are satisfied. The model is well applied to an existing water distribution system, the Seoul Metropolitan Water Supply System (1st Phase). The results show that the decisions for the replacement time determined by the economic analysis are accepted as optimal and hydraulic integrity of the system is in good condition.

• Journal of Korea Water Resources Association
• /
• v.32 no.2
• /
• pp.143-152
• /
• 1999

South-eastern part of Kyungbuk Province is suffering from lack of suitable water development sources due to geographic condition and insufficient water sources condition. In order to find an appropriate solution, extensive studies are carried out such as investigation of new dam sites, regional water supply system, modification of existing water supply system, rehabilitation of old water resources structures and development of off-stream reservoirs. The network optimization model is applied for evaluation of the newly suggested water development alternatives. The results show that if water supply system is constructed until 2011, the reliability of water supply to Pohang and Kyungju region will be more than 95% and the network optimization model can be used to analyse the management of water resources system considering water rights or priority orders.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2015.05a
• /
• pp.635-635
• /
• 2015

1960년대부터 우리나라는 증가하는 용수수요에 대한 안정적인 생 공용수 공급, 수력발전, 하천생태계 유지를 위한 하천유지용수 공급 및 하천 연안지역의 홍수피해 경감 등의 목적으로 댐 사업이 본격적으로 시작되었다. 그러나 현재 댐 건설적지의 감소, 환경보전에 대한 인식 증대 및 지역 주민의 반대 등으로 신규 댐건설에 한계가 있는 실정이다. 또한 국제적으로 댐 건설 패러다임의 변화로 지속가능한 개발을 위한 노후화된 댐의 개량이 새로운 방안으로 제시됨에 따라 국내에서도 이에 대한 대안으로 기존 댐 재개발의 필요성이 대두되고 있다. 한정된 자원과 인력을 통해 댐 재개발의 효과를 극대화하기 위해서는 댐 재개발 우선순위 결정이 필수적이다. 국내에서도 이에 대한 연구가 진행되어 수자원공사 및 농어촌공사에서 각각 댐 및 농업용 저수지의 재개발 우선순위 평가기법을 제시하였으나 최근 기후변화로 인한 영향이 고려되지 않았을 뿐만 아니라 공공서비스 향상, 고령화율과 안전, 환경 및 지역사회 등 여러 측면을 고려한 기준이 제시되어 있지 않았다. 또한 국내 댐 재개발 우선순위 평가 기술은 다른 선진 국가들에 비해 기술적으로 많이 뒤떨어진 실정이다. 본 연구에서는 국내 댐 재개발 우선순위 평가기준 개발을 위한 국내외 사례조사 및 비교분석을 통해 기존의 댐 재개발 우선순위 결정 기술에서 나아가 기후변화 및 시대적 환경적 측면을 고려한 다 기준 댐 재개발 우선순위를 개발하여 향후 기후변화 적응 댐 재개발 실행프레임워크 구축 기술에 활용하고자 한다.