• 한국환경과학회지
• /
• 제17권11호
• /
• pp.1281-1293
• /
• 2008

This study aims at the estimation of dam failure time and dam failure scenario analysis of and applied to Yeoncheon Dam which was collapsed August 1st 1999, using HEC-HMS, DAMBRK-FLDWAV simulation model. As the result of the rainfall-runoff simulation, the lancet flood amount of the Yeoncheon Dam site was $10,324\;m^3/sec$ and the total outflow was $1,263.90\;million\;m^3$. For the dam failure time estimation, 13 scenarios were assumed including dam failure duration time and starting time, which reviewed to the runoff results. The simulation time was established with 30 minutes intervals between one o'clock to 4 o'clock in the morning on August 1, 1999 for the setup standard for each case of the dam failure time estimation, considering the arrival time of the flood, when the actually measured water level was sharply raising at Jeongok station area of the Yeoncheon Dam downstream, As results, dam failure arrival time could be estimated at 02:45 a.m., August 1st 1999 and duration time could be also 30 minutes. Those results and procedure could suggest how and when dam failure occurs and analyzes.

• 한국환경과학회지
• /
• 제17권11호
• /
• pp.1295-1305
• /
• 2008

This study aims at the analyze of unsteady downstream flow due to dam failure along dam failure scenario and applied to Yeoncheon Dam which was collapsed August 1st 1999, using HEC-RAS simulation model. The boundary conditions of this unsteady flow simulation are that dam failure arrival time could be at 02:45 a.m. August 1st 1999 and failure duration time could be also 30 minutes. Downstream 19.5 km from dam site was simulated for unsteady flow analysis in terms of dam failure and non-failure cases. For the parameter calibration, observed data of Jeonkok station were used and roughness coefficient was applied to simulation model. The result of the peak discharge difference was 2,696 to $1,745\;m^3/sec$ along the downstream between dam failure and non-failure and also peak elevation of water level showed meanly 0.6m difference. Those results of these studies show that dam failure scenarios for the unknown failure time and duration were rational because most results were coincident with observed records. And also those results and procedure could suggest how and when dam failure occurs and downstream unsteady flow analyzes.

• Journal of Forest and Environmental Science
• /
• 제30권1호
• /
• pp.76-84
• /
• 2014

This study was performed to monitor the effects of water level change on changes of landscape, vegetation community, and species diversity of riparian forest. Hantan river dam, study area, has been constructed in the area of Chansoo-myeon, Pocheon-si and Yeoncheon-eup, Yeoncheon-gun, Gyeonggi-do, which is a dam for flood control only in flooding season. Landscape changes were notable after the construction of coffer dam, and the changes were caused by water level increase in areas of riparian forests which consisted of mainly withered willow as a dominant species in the flooding season. It changed vegetation communities of riparian forest from Phragmites japonica and Salix koreensis to Phragmites japonica. Species diversity index was lowest in 2010 when the coffer dam was constructed and showed an increasing trend later. Thus, this study is well in agreement with a previous report that plants of the genus Salix wither by muddy water during flooding and also suggests, controlling water level of river and prediction of water level change's effects should be considered when any facilities are planned.

• 한국환경과학회지
• /
• 제20권12호
• /
• pp.1635-1646
• /
• 2011

This April 5th dam and Hwanggang dam, which are located in Imjin river, North Korea, become the main causes of water shortages and damages in Imjin river downstream. April 5th dam is assumed a small or medium-sized dam, its total storage volume reaches about 88 million $m^3$. And Hwanggang dam, multi-purposed dam of total storage volume approximately 0.3 billion $m^3$ to 0.4 billion $m^3$ is used as source of residental or industrial water in Gaeseong Industrial Complex. North Korea, which has April 5th dam and Hwanggang dam in Imjin river, manages water of approximately 0.39 billion $m^3$ to 0.49 billion $m^3$ directly. As water is storaged or discharged through dam, it causes a severe damage to areas in Yeoncheon-gun and Paju city, South Korea. Therefore, this study intends to analyze and estimate runoff through dam construction by using hydrological observation data and artificial data such as service water supply and agricultural water in Imjin river, water shortage and damage correctly.

• 한국지진공학회논문집
• /
• 제18권6호
• /
• pp.271-278
• /
• 2014

Seismic intensity deduced from instrumental data has been evaluated using the empirical relationship between intensity and peak ground acceleration (PGA) during an earthquake. The Japan Meteorological Agency (JMA) developed a seismic intensity meter, which can estimate the real-time seismic intensity from seismic motions observed at a local site to evaluate the damage during the earthquake more correctly. This paper proposes a practical application of the JMA intensity to dams during the 2013 earthquake in Yeongcheon, Korea. In the present paper, seismic intensity was estimated from the relationships between accelerations observed at Yeongcheon Dam. Estimated seismic intensities were in the range of 0 to 3, which was verified from the displacements of dams and the variation of the ground water level observed at Yeongcheon dam during the earthquake. The JMA intensity, which is determined by considering the frequency, duration of cyclic loading, etc., was 0 (zero) and there was no damage to Yeoncheon dam during the earthquake.

• 대한원격탐사학회지
• /
• 제34권6_1호
• /
• pp.1033-1039
• /
• 2018

우리나라는 매년 여름철마다 태풍과 집중호우가 함께 발생하는 홍수로 인해 인명 및 재산피해가 발생한다. 특히 임진강 유역은 급경사와 좁은 하도인 상류부와, 낮은 평지인 하류부로 되어 있어 홍수에 취약한 지형을 가지고 있다. 게다가 북한 지역의 임진강 상류에 위치한 대형 댐인 황강댐에서 여름철 마다 무단방류로 인하여 피해가 발생하였다. 이런 홍수 피해를 방지하기 위해 우리나라에서는 2010년 군남홍수조절지를 건설하여 홍수피해를 방지하고 있다. 하지만 홍수조절지의 건설 이후에도 홍수조절능력이 황강댐의 최대 저수량의 20%밖에 미치지 못한다. 이에 이 연구에서는 경기북부지역의 집중호우시 발생할 수 있는 홍수 피해 위험지역을 산정하기 위하여 LAHARZ_py 프로그램을 이용하여 피해예상지역을 산출하였다. 그 결과 군남홍수조절지의 홍수조절능력을 넘는 황강댐의 방류가 발생할 시에 경기도 연천군과 파주시에 피해가 예상되었다. 추후 이 연구는 홍수 피해를 대비하기 위한 자료로 유용할 것으로 판단된다.

• 식물분류학회지
• /
• 제45권4호
• /
• pp.362-368
• /
• 2015

꼬리고사리속의 두 개의 신교잡종과 한 개의 미기록교잡종이 발견되었다. 이들 종들의 형태적 형질에 있어 부모종들의 중간형태를 보였다. 거미사철고사리($A.{\times}uiryeongse$)는 서울 북한산 우이령길에서 발견되었고 거미고사리와 사철고사리의 교잡에 의해 분화되었다. 다른 교잡종, 산꼬리고사리($A.{\times}montanus$)는 경기도 연천군, 성산에서 발견되었고, 거미고사리와 차꼬리고사리가 교잡에 의해 만들어지고 다시 꼬리고사리와의 중복교잡에 의해 형성되었다. 아울러 미기록 교잡종인 거미돌담고사리($A.{\times}kitazawae$)는 대구 도동에서 발견되었고, 거미고사리와 돌담고사리의 교잡에 의해 형성되었다. 이들 교잡종들은 부모종들과 같은 장소에서 자란다. 각 분류군의 형질을 분석해 교잡종임을 입증해 보였으며, 이들에 대한 기재, 도해 및 자생지의 서식 사진을 수록하였다.